diff options
| -rw-r--r-- | Makefile | 56 | ||||
| -rw-r--r-- | src/app.c | 41 | ||||
| -rw-r--r-- | src/libandroid.c | 464 | ||||
| -rw-r--r-- | src/libc-sha1.h | 302 | ||||
| -rw-r--r-- | src/libc.c | 64 | ||||
| -rw-r--r-- | src/liblog.c | 19 | ||||
| -rw-r--r-- | src/libpthread.c | 178 | ||||
| -rw-r--r-- | src/linker/NOTICE | 190 | ||||
| -rw-r--r-- | src/linker/README.TXT | 144 | ||||
| -rw-r--r-- | src/linker/bionic_tls.h | 141 | ||||
| -rw-r--r-- | src/linker/dlfcn.c | 333 | ||||
| -rw-r--r-- | src/linker/linker.c | 2541 | ||||
| -rw-r--r-- | src/linker/linker.h | 226 | ||||
| -rw-r--r-- | src/linker/linker_debug.h | 154 | ||||
| -rw-r--r-- | src/linker/linker_environ.c | 204 | ||||
| -rw-r--r-- | src/linker/linker_environ.h | 54 | ||||
| -rw-r--r-- | src/linker/linker_format.h | 43 | ||||
| -rw-r--r-- | src/linker/rt.c | 36 | ||||
| -rw-r--r-- | src/linker/strlcpy.c | 50 | ||||
| -rw-r--r-- | src/linker/strlcpy.h | 10 |
20 files changed, 5250 insertions, 0 deletions
diff --git a/Makefile b/Makefile new file mode 100644 index 0000000..c9c552a --- /dev/null +++ b/Makefile @@ -0,0 +1,56 @@ +PREFIX ?= /usr/local +BINDIR ?= /bin + +MAKEFLAGS += --no-builtin-rules + +# GCC 7: -Wstringop-overflow=, -Walloc-size-larger-than=, -Wduplicated-{branches,cond} +WARNINGS := -Wall -Wextra -Wpedantic -Wformat=2 -Wstrict-aliasing=3 -Wstrict-overflow=3 -Wstack-usage=12500 \ + -Wfloat-equal -Wcast-align -Wpointer-arith -Wchar-subscripts -Warray-bounds=2 -Wno-unused-parameter + +override CFLAGS ?= -g +override CFLAGS += -std=c11 $(WARNINGS) +override CPPFLAGS += -Isrc + +bins = app +all: $(bins) runtime/libc.so runtime/libandroid.so runtime/liblog.so + +%.o: %.c + $(COMPILE.c) $^ -o $@ + +%.so: + $(LINK.c) -shared $(filter %.c,$^) $(LDLIBS) -o $@ + +%.a: + $(AR) rvs $@ $^ + +$(bins): %: + $(LINK.c) $(filter %.c %.a,$^) $(LDLIBS) -o $@ + +runtime: + mkdir -p $@ + +runtime/libc.so: private CFLAGS += -D_GNU_SOURCE +runtime/libc.so: runtime src/libc.c +runtime/libpthread.so: private CFLAGS += -D_GNU_SOURCE +runtime/libpthread.so: private LDLIBS += -lpthread +runtime/libpthread.so: runtime src/libpthread.c +runtime/libandroid.so: runtime src/libandroid.c +runtime/liblog.so: runtime src/liblog.c + +linker.a: CFLAGS += -D_GNU_SOURCE -DANDROID_X86_LINKER -DLINKER_DEBUG=1 +linker.a: CFLAGS += -Wno-pedantic -Wno-variadic-macros -Wno-pointer-to-int-cast -Wno-int-to-pointer-cast +linker.a: src/linker/dlfcn.o src/linker/linker.o src/linker/linker_environ.o src/linker/rt.o src/linker/strlcpy.o + +app: private LDLIBS += -ldl -Wl,-rpath,runtime +app: src/app.c linker.a runtime/libc.so runtime/libpthread.so runtime/libandroid.so runtime/liblog.so + +install-bin: $(bins) + install -Dm755 $^ -t "$(DESTDIR)$(PREFIX)$(BINDIR)" + +install: install-bin + +clean: + $(RM) $(bins) *.a src/linker/*.o + $(RM) -r runtime + +.PHONY: all clean install diff --git a/src/app.c b/src/app.c new file mode 100644 index 0000000..6dd8e10 --- /dev/null +++ b/src/app.c @@ -0,0 +1,41 @@ +#include <stdlib.h> +#include <stdio.h> +#include <libgen.h> +#include <dlfcn.h> +#include <err.h> +#include <assert.h> + +extern void *apkenv_android_dlopen(const char*, int); +extern void *apkenv_android_dlclose(void*); +extern void *apkenv_android_dlsym(void*, const char*); +extern void apkenv_parse_library_path(const char *path, char *delim); + +int +main(int argc, const char *argv[]) +{ + if (argc < 2) + errx(EXIT_FAILURE, "usage: so-file"); + + dlopen("libpthread.so", RTLD_NOW | RTLD_GLOBAL); + + printf("loading: %s\n", argv[1]); + + char path[4096]; + snprintf(path, sizeof(path), "%s", argv[1]); + apkenv_parse_library_path(dirname(path), ";"); + + void *handle; + if (!(handle = apkenv_android_dlopen(argv[1], RTLD_NOW | RTLD_LOCAL))) + errx(EXIT_FAILURE, "dlopen failed: %s", dlerror()); + + printf("loaded: %s\n", argv[1]); + + void* (*JNI_OnLoad)(void*, void*) = apkenv_android_dlsym(handle, "JNI_OnLoad"); + assert(JNI_OnLoad); + + char data[1024]; + JNI_OnLoad(data, NULL); + + // apkenv_android_dlclose(handle); + return EXIT_SUCCESS; +} diff --git a/src/libandroid.c b/src/libandroid.c new file mode 100644 index 0000000..fb58bd7 --- /dev/null +++ b/src/libandroid.c @@ -0,0 +1,464 @@ +#include <stddef.h> +#include <stdint.h> +#include <stdlib.h> + +// System + +#define PROP_NAME_MAX 32 +#define PROP_VALUE_MAX 92 + +int __system_property_get(const char *name, char *value) +{ + return 0; +} + +// AConfiguration + +struct AConfiguration +{ +}; + +struct AAssetManager +{ +}; + +struct AConfiguration* +AConfiguration_new(void) +{ + return calloc(1, sizeof(struct AConfiguration)); +} + +void +AConfiguration_delete(struct AConfiguration *config) +{ + free(config); +} + +void +AConfiguration_fromAssetManager(struct AConfiguration *out, struct AAssetManager *am) +{ +} + +// ALooper + +static struct ALooper +{ +} thread_looper; + +typedef void* ALooper_callbackFunc; + +struct ALooper* +ALooper_forThread(void) +{ + return &thread_looper; +} + +struct ALooper* +ALooper_prepare(int opts) +{ + return &thread_looper; +} + +void +ALooper_wake(struct ALooper *looper) +{ +} + +int +ALooper_pollAll(int timeoutMillis, int *outFd, int *outEvents, void **outData) +{ + return 0; +} + +// ASensor + +struct ASensor { +}; + +const char* +ASensor_getName(struct ASensor const *sensor) +{ + return NULL; +} + +const char* +ASensor_getVendor(struct ASensor const *sensor) +{ + return NULL; +} + +int +ASensor_getType(struct ASensor const *sensor) +{ + return 0; +} + +float +ASensor_getResolution(struct ASensor const *sensor) +{ + return 0; +} + +int +ASensor_getMinDelay(struct ASensor const *sensor) +{ + return 0; +} + +struct ASensorEvent { +}; + +struct ASensorEventQueue { +}; + +int +ASensorEventQueue_enableSensor(struct ASensorEventQueue *queue, struct ASensor const *sensor) +{ + return 0; +} + +int +ASensorEventQueue_disableSensor(struct ASensorEventQueue *queue, struct ASensor const *sensor) +{ + return 0; +} + +int +ASensorEventQueue_setEventRate(struct ASensorEventQueue *queue, struct ASensor const *sensor, int32_t usec) +{ + return 0; +} + +int +ASensorEventQueue_hasEvents(struct ASensorEventQueue *queue) +{ + return 0; +} + +size_t +ASensorEventQueue_getEvents(struct ASensorEventQueue *queue, struct ASensorEvent *events, size_t count) +{ + return 0; +} + +struct ASensorManager { +}; + +struct ASensorList { +}; + +struct ASensorManager* +ASensorManager_getInstance() +{ + return NULL; +} + +struct ASensor const* +ASensorManager_getDefaultSensor(struct ASensorManager *manager, int type) +{ + return NULL; +} + +int +ASensorManager_getSensorList(struct ASensorManager *manager, struct ASensorList *list) +{ + return 0; +} + +struct ASensorEventQueue* +ASensorManager_createEventQueue(struct ASensorManager *manager, struct ALooper *looper, int ident, ALooper_callbackFunc callback, void *data) +{ + return NULL; +} + +int +ASensorManager_destroyEventQueue(struct ASensorManager *manager, struct ASensorEventQueue *queue) +{ + return 0; +} + +// AInput + +struct AInputEvent +{ +}; + +int32_t +AInputEvent_getType(const struct AInputEvent *event) +{ + return 0; +} + +int32_t +AInputEvent_getDeviceId(const struct AInputEvent *event) +{ + return 0; +} + +int32_t +AInputEvent_getSource(const struct AInputEvent *event) +{ + return 0; +} + +int32_t +AMotionEvent_getEdgeFlags(const struct AInputEvent *motion_event) +{ + return 0; +} + +float +AMotionEvent_getTouchMajor(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +float +AMotionEvent_getTouchMinor(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +int32_t +AMotionEvent_getPointerId(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +int64_t +AMotionEvent_getDownTime(const struct AInputEvent *motion_event) +{ + return 0; +} + +size_t +AMotionEvent_getPointerCount(const struct AInputEvent *motion_event) +{ + return 0; +} + +float +AMotionEvent_getXPrecision(const struct AInputEvent *motion_event) +{ + return 0; +} + +float +AMotionEvent_getYPrecision(const struct AInputEvent *motion_event) +{ + return 0; +} + +float +AMotionEvent_getToolMajor(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +float +AMotionEvent_getToolMinor(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +float +AMotionEvent_getX(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +float +AMotionEvent_getY(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +float +AMotionEvent_getSize(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +float +AMotionEvent_getPressure(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +int64_t +AMotionEvent_getEventTime(const struct AInputEvent *motion_event) +{ + return 0; +} + +int32_t +AMotionEvent_getFlags(const struct AInputEvent *motion_event) +{ + return 0; +} + +int32_t +AMotionEvent_getMetaState(const struct AInputEvent *motion_event) +{ + return 0; +} + +int32_t +AMotionEvent_getAction(const struct AInputEvent *motion_event) +{ + return 0; +} + +size_t +AMotionEvent_getHistorySize(const struct AInputEvent *motion_event) +{ + return 0; +} + +int64_t +AMotionEvent_getHistoricalEventTime(const struct AInputEvent *motion_event, size_t history_index) +{ + return 0; +} + +size_t +AMotionEvent_getHistoricalSize(const struct AInputEvent *motion_event, size_t pointer_index, size_t history_index) +{ + return 0; +} + +float +AMotionEvent_getHistoricalPressure(const struct AInputEvent *motion_event, size_t pointer_index, size_t history_index) +{ + return 0; +} + +float +AMotionEvent_getHistoricalX(const struct AInputEvent *motion_event, size_t pointer_index, size_t history_index) +{ + return 0; +} + +float +AMotionEvent_getHistoricalY(const struct AInputEvent *motion_event, size_t pointer_index, size_t history_index) +{ + return 0; +} + +float +AMotionEvent_getOrientation(const struct AInputEvent *motion_event, size_t pointer_index) +{ + return 0; +} + +int32_t +AKeyEvent_getKeyCode(const struct AInputEvent *key_event) +{ + return 0; +} + +int32_t +AKeyEvent_getMetaState(const struct AInputEvent *key_event) +{ + return 0; +} + +int32_t +AKeyEvent_getAction(const struct AInputEvent *key_event) +{ + return 0; +} + +struct AInputQueue +{ +}; + +void +AInputQueue_attachLooper(struct AInputQueue *queue, struct ALooper *looper, int ident, ALooper_callbackFunc callback, void *data) +{ +} + +void +AInputQueue_detachLooper(struct AInputQueue *queue) +{ +} + +int32_t +AInputQueue_getEvent(struct AInputQueue *queue, struct AInputEvent **outEvent) +{ + return 0; +} + +int32_t +AInputQueue_preDispatchEvent(struct AInputQueue *queue, struct AInputEvent *event) +{ + return 0; +} + +void +AInputQueue_finishEvent(struct AInputQueue *queue, struct AInputEvent *event, int handled) +{ +} + +// ANative + +struct ANativeWindow +{ +}; + +struct ANativeWindow_Buffer +{ +}; + +struct ARect +{ +}; + +typedef void JNIEnv; +typedef uint32_t jobject; + +struct ANativeWindow* +ANativeWindow_fromSurface(JNIEnv* env, jobject surface) +{ + return NULL; +} + +void +ANativeWindow_acquire(struct ANativeWindow *window) +{ +} + +void +ANativeWindow_release(struct ANativeWindow *window) +{ +} + +int32_t +ANativeWindow_getWidth(struct ANativeWindow *window) +{ + return 0; +} + +int32_t +ANativeWindow_getHeight(struct ANativeWindow *window) +{ + return 0; +} + +int32_t +ANativeWindow_setBuffersGeometry(struct ANativeWindow *window, int32_t width, int32_t height, int32_t format) +{ + return 0; +} + +int32_t +ANativeWindow_lock(struct ANativeWindow *window, struct ANativeWindow_Buffer *outBuffer, struct ARect *inOutDirtyBounds) +{ + return 0; +} + +int32_t +ANativeWindow_unlockAndPost(struct ANativeWindow *window) +{ + return 0; +} diff --git a/src/libc-sha1.h b/src/libc-sha1.h new file mode 100644 index 0000000..43b562a --- /dev/null +++ b/src/libc-sha1.h @@ -0,0 +1,302 @@ +#pragma once + +/* + SHA-1 in C + By Steve Reid <steve@edmweb.com> + 100% Public Domain + */ + +#include <stdint.h> + +typedef struct +{ + uint32_t state[5]; + uint32_t count[2]; + unsigned char buffer[64]; +} SHA1_CTX; + +/* +Test Vectors (from FIPS PUB 180-1) +"abc" + A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D +"abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq" + 84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1 +A million repetitions of "a" + 34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F +*/ + +/* #define LITTLE_ENDIAN * This should be #define'd already, if true. */ +/* #define SHA1HANDSOFF * Copies data before messing with it. */ + +#define SHA1HANDSOFF + +#include <stdio.h> +#include <string.h> + +#define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits)))) + +/* blk0() and blk() perform the initial expand. */ +/* I got the idea of expanding during the round function from SSLeay */ +#if BYTE_ORDER == LITTLE_ENDIAN +#define blk0(i) (block->l[i] = (rol(block->l[i],24)&0xFF00FF00) \ + |(rol(block->l[i],8)&0x00FF00FF)) +#elif BYTE_ORDER == BIG_ENDIAN +#define blk0(i) block->l[i] +#else +#error "Endianness not defined!" +#endif +#define blk(i) (block->l[i&15] = rol(block->l[(i+13)&15]^block->l[(i+8)&15] \ + ^block->l[(i+2)&15]^block->l[i&15],1)) + +/* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */ +#define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk0(i)+0x5A827999+rol(v,5);w=rol(w,30); +#define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)+blk(i)+0x5A827999+rol(v,5);w=rol(w,30); +#define R2(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0x6ED9EBA1+rol(v,5);w=rol(w,30); +#define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk(i)+0x8F1BBCDC+rol(v,5);w=rol(w,30); +#define R4(v,w,x,y,z,i) z+=(w^x^y)+blk(i)+0xCA62C1D6+rol(v,5);w=rol(w,30); + + +/* Hash a single 512-bit block. This is the core of the algorithm. */ + +void SHA1Transform( + uint32_t state[5], + const unsigned char buffer[64] +) +{ + uint32_t a, b, c, d, e; + + typedef union + { + unsigned char c[64]; + uint32_t l[16]; + } CHAR64LONG16; + +#ifdef SHA1HANDSOFF + CHAR64LONG16 block[1]; /* use array to appear as a pointer */ + + memcpy(block, buffer, 64); +#else + /* The following had better never be used because it causes the + * pointer-to-const buffer to be cast into a pointer to non-const. + * And the result is written through. I threw a "const" in, hoping + * this will cause a diagnostic. + */ + CHAR64LONG16 *block = (const CHAR64LONG16 *) buffer; +#endif + /* Copy context->state[] to working vars */ + a = state[0]; + b = state[1]; + c = state[2]; + d = state[3]; + e = state[4]; + /* 4 rounds of 20 operations each. Loop unrolled. */ + R0(a, b, c, d, e, 0); + R0(e, a, b, c, d, 1); + R0(d, e, a, b, c, 2); + R0(c, d, e, a, b, 3); + R0(b, c, d, e, a, 4); + R0(a, b, c, d, e, 5); + R0(e, a, b, c, d, 6); + R0(d, e, a, b, c, 7); + R0(c, d, e, a, b, 8); + R0(b, c, d, e, a, 9); + R0(a, b, c, d, e, 10); + R0(e, a, b, c, d, 11); + R0(d, e, a, b, c, 12); + R0(c, d, e, a, b, 13); + R0(b, c, d, e, a, 14); + R0(a, b, c, d, e, 15); + R1(e, a, b, c, d, 16); + R1(d, e, a, b, c, 17); + R1(c, d, e, a, b, 18); + R1(b, c, d, e, a, 19); + R2(a, b, c, d, e, 20); + R2(e, a, b, c, d, 21); + R2(d, e, a, b, c, 22); + R2(c, d, e, a, b, 23); + R2(b, c, d, e, a, 24); + R2(a, b, c, d, e, 25); + R2(e, a, b, c, d, 26); + R2(d, e, a, b, c, 27); + R2(c, d, e, a, b, 28); + R2(b, c, d, e, a, 29); + R2(a, b, c, d, e, 30); + R2(e, a, b, c, d, 31); + R2(d, e, a, b, c, 32); + R2(c, d, e, a, b, 33); + R2(b, c, d, e, a, 34); + R2(a, b, c, d, e, 35); + R2(e, a, b, c, d, 36); + R2(d, e, a, b, c, 37); + R2(c, d, e, a, b, 38); + R2(b, c, d, e, a, 39); + R3(a, b, c, d, e, 40); + R3(e, a, b, c, d, 41); + R3(d, e, a, b, c, 42); + R3(c, d, e, a, b, 43); + R3(b, c, d, e, a, 44); + R3(a, b, c, d, e, 45); + R3(e, a, b, c, d, 46); + R3(d, e, a, b, c, 47); + R3(c, d, e, a, b, 48); + R3(b, c, d, e, a, 49); + R3(a, b, c, d, e, 50); + R3(e, a, b, c, d, 51); + R3(d, e, a, b, c, 52); + R3(c, d, e, a, b, 53); + R3(b, c, d, e, a, 54); + R3(a, b, c, d, e, 55); + R3(e, a, b, c, d, 56); + R3(d, e, a, b, c, 57); + R3(c, d, e, a, b, 58); + R3(b, c, d, e, a, 59); + R4(a, b, c, d, e, 60); + R4(e, a, b, c, d, 61); + R4(d, e, a, b, c, 62); + R4(c, d, e, a, b, 63); + R4(b, c, d, e, a, 64); + R4(a, b, c, d, e, 65); + R4(e, a, b, c, d, 66); + R4(d, e, a, b, c, 67); + R4(c, d, e, a, b, 68); + R4(b, c, d, e, a, 69); + R4(a, b, c, d, e, 70); + R4(e, a, b, c, d, 71); + R4(d, e, a, b, c, 72); + R4(c, d, e, a, b, 73); + R4(b, c, d, e, a, 74); + R4(a, b, c, d, e, 75); + R4(e, a, b, c, d, 76); + R4(d, e, a, b, c, 77); + R4(c, d, e, a, b, 78); + R4(b, c, d, e, a, 79); + /* Add the working vars back into context.state[] */ + state[0] += a; + state[1] += b; + state[2] += c; + state[3] += d; + state[4] += e; + /* Wipe variables */ + a = b = c = d = e = 0; +#ifdef SHA1HANDSOFF + memset(block, '\0', sizeof(block)); +#endif +} + + +/* SHA1Init - Initialize new context */ + +void SHA1Init( + SHA1_CTX * context +) +{ + /* SHA1 initialization constants */ + context->state[0] = 0x67452301; + context->state[1] = 0xEFCDAB89; + context->state[2] = 0x98BADCFE; + context->state[3] = 0x10325476; + context->state[4] = 0xC3D2E1F0; + context->count[0] = context->count[1] = 0; +} + + +/* Run your data through this. */ + +void SHA1Update( + SHA1_CTX * context, + const unsigned char *data, + uint32_t len +) +{ + uint32_t i; + + uint32_t j; + + j = context->count[0]; + if ((context->count[0] += len << 3) < j) + context->count[1]++; + context->count[1] += (len >> 29); + j = (j >> 3) & 63; + if ((j + len) > 63) + { + memcpy(&context->buffer[j], data, (i = 64 - j)); + SHA1Transform(context->state, context->buffer); + for (; i + 63 < len; i += 64) + { + SHA1Transform(context->state, &data[i]); + } + j = 0; + } + else + i = 0; + memcpy(&context->buffer[j], &data[i], len - i); +} + + +/* Add padding and return the message digest. */ + +void SHA1Final( + unsigned char digest[20], + SHA1_CTX * context +) +{ + unsigned i; + + unsigned char finalcount[8]; + + unsigned char c; + +#if 0 /* untested "improvement" by DHR */ + /* Convert context->count to a sequence of bytes + * in finalcount. Second element first, but + * big-endian order within element. + * But we do it all backwards. + */ + unsigned char *fcp = &finalcount[8]; + + for (i = 0; i < 2; i++) + { + uint32_t t = context->count[i]; + + int j; + + for (j = 0; j < 4; t >>= 8, j++) + *--fcp = (unsigned char) t} +#else + for (i = 0; i < 8; i++) + { + finalcount[i] = (unsigned char) ((context->count[(i >= 4 ? 0 : 1)] >> ((3 - (i & 3)) * 8)) & 255); /* Endian independent */ + } +#endif + c = 0200; + SHA1Update(context, &c, 1); + while ((context->count[0] & 504) != 448) + { + c = 0000; + SHA1Update(context, &c, 1); + } + SHA1Update(context, finalcount, 8); /* Should cause a SHA1Transform() */ + for (i = 0; i < 20; i++) + { + digest[i] = (unsigned char) + ((context->state[i >> 2] >> ((3 - (i & 3)) * 8)) & 255); + } + /* Wipe variables */ + memset(context, '\0', sizeof(*context)); + memset(&finalcount, '\0', sizeof(finalcount)); +} + +void SHA1( + char *hash_out, + const char *str, + int len) +{ + SHA1_CTX ctx; + int ii; + + SHA1Init(&ctx); + for (ii=0; ii<len; ii+=1) + SHA1Update(&ctx, (const unsigned char*)str + ii, 1); + SHA1Final((unsigned char *)hash_out, &ctx); + hash_out[20] = '\0'; +} diff --git a/src/libc.c b/src/libc.c new file mode 100644 index 0000000..f83395b --- /dev/null +++ b/src/libc.c @@ -0,0 +1,64 @@ +#include <unistd.h> +#include <stdint.h> +#include <stdlib.h> +#include <stdio.h> +#include <math.h> +#include <sys/stat.h> +#include <sys/types.h> +#include <sys/syscall.h> + +// Stuff that doesn't exist in glibc + +void +__assert2(const char* file, int line, const char* function, const char* failed_expression) +{ + fprintf(stderr, "%s:%d: %s: assertion \"%s\" failed", file, line, function, failed_expression); + abort(); +} + +pid_t +gettid(void) +{ + return syscall(SYS_gettid); +} + +#include "libc-sha1.h" + +// Stuff needed for runtime compatibility, but not neccessary for linking +// Also stuff that exists in glibc, but needs to be wrapped for runtime compatibility + +const char *bionic__ctype_, *bionic__tolower_tab_, *bionic__toupper_tab_; +char bionic___sF[0x54]; +int bionic___errno; + +int +bionic_stat(const char *restrict path, struct stat *restrict buf) +{ + return stat(path, buf); +} + +int +bionic_lstat(const char *restrict path, struct stat *restrict buf) +{ + return lstat(path, buf); +} + +int +bionic_fstat(int fd, struct stat *buf) +{ + return fstat(fd, buf); +} + +int +bionic___isfinitef(float f) +{ + return isfinite(f); +} + +uintptr_t bionic___stack_chk_guard = 4; + +__attribute__((noreturn)) +void bionic___stack_chk_fail(void) +{ + abort(); +} diff --git a/src/liblog.c b/src/liblog.c new file mode 100644 index 0000000..522166e --- /dev/null +++ b/src/liblog.c @@ -0,0 +1,19 @@ +#include <stdarg.h> + +int +__android_log_print(int prio, const char *tag, const char *fmt, ...) +{ + return 0; +} + +int +__android_log_vprint(int prio, const char *tag, const char *fmt, va_list ap) +{ + return 0; +} + +int +__android_log_write(int prio, const char *tag, const char *text) +{ + return 0; +} diff --git a/src/libpthread.c b/src/libpthread.c new file mode 100644 index 0000000..3359c4a --- /dev/null +++ b/src/libpthread.c @@ -0,0 +1,178 @@ +#include <stdint.h> +#include <stdbool.h> +#include <unistd.h> +#include <memory.h> +#include <pthread.h> +#include <assert.h> +#include <sys/mman.h> + +typedef struct { + union { +#if defined(__LP64__) + int32_t __private[10]; +#else + int32_t __private[1]; +#endif + void *glibc; + }; +} bionic_mutex_t; + +typedef struct { + union { + long __private; + void *glibc; + }; +} bionic_mutexattr_t; + +static const struct { + bionic_mutex_t bionic; + pthread_mutex_t glibc; +} bionic_mutex_init_map[] = { + { .bionic = {{{ ((PTHREAD_MUTEX_NORMAL & 3) << 14) }}}, .glibc = PTHREAD_MUTEX_INITIALIZER }, + { .bionic = {{{ ((PTHREAD_MUTEX_RECURSIVE & 3) << 14) }}}, .glibc = PTHREAD_RECURSIVE_MUTEX_INITIALIZER_NP }, + { .bionic = {{{ ((PTHREAD_MUTEX_ERRORCHECK & 3) << 14) }}}, .glibc = PTHREAD_ERRORCHECK_MUTEX_INITIALIZER_NP }, +}; + +typedef struct { + union { +#if defined(__LP64__) + int32_t __private[12]; +#else + int32_t __private[1]; +#endif + void *glibc; + }; +} bionic_cond_t; + +typedef struct { + union { + long __private; + void *glibc; + }; +} bionic_condattr_t; + +typedef int bionic_key_t; + +_Static_assert(sizeof(bionic_key_t) == sizeof(pthread_key_t), "bionic_key_t and pthread_key_t size mismatch"); + +#define ARRAY_SIZE(x) (sizeof(x) / sizeof(x[0])) +#define IS_MAPPED(x) is_mapped(x->glibc, sizeof(x)) +#define INIT_IF_NOT_MAPPED(x, init) do { if (!IS_MAPPED(x)) init(x); } while(0) + +static bool +is_mapped(void *mem, const size_t sz) +{ + const size_t ps = sysconf(_SC_PAGESIZE); + assert(ps > 0); + unsigned char vec[(sz + ps - 1) / ps]; + return !mincore(mem, sz, vec); +} + +int +bionic_pthread_cond_timedwait_monotonic_np(bionic_cond_t *cond, bionic_mutex_t *mutex, const struct timespec *abstime) +{ + return 0; +} + +int +bionic_pthread_mutexattr_settype(bionic_mutexattr_t *attr, int type) +{ + assert(attr && IS_MAPPED(attr)); + return pthread_mutexattr_settype(attr->glibc, type); +} + +int +bionic_pthread_mutexattr_destroy(bionic_mutexattr_t *attr) +{ + assert(attr); + int ret = 0; + if (IS_MAPPED(attr)) { + ret = pthread_mutexattr_destroy(attr->glibc); + munmap(attr->glibc, sizeof(pthread_mutexattr_t)); + } + return ret; +} + +int +bionic_pthread_mutexattr_init(bionic_mutexattr_t *attr) +{ + assert(attr); + if (!IS_MAPPED(attr)) + attr->glibc = mmap(NULL, sizeof(pthread_mutexattr_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + return pthread_mutexattr_init(attr->glibc); +} + +int +bionic_pthread_mutex_destroy(bionic_mutex_t *mutex) +{ + assert(mutex); + int ret = 0; + if (IS_MAPPED(mutex)) { + ret = pthread_mutex_destroy(mutex->glibc); + munmap(mutex->glibc, sizeof(pthread_mutex_t)); + } + return ret; +} + +int +bionic_pthread_mutex_init(bionic_mutex_t *mutex, const bionic_mutexattr_t *attr) +{ + assert(mutex && (!attr || IS_MAPPED(attr))); + if (!IS_MAPPED(mutex)) + mutex->glibc = mmap(NULL, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + return pthread_mutex_init(mutex->glibc, (attr ? attr->glibc : NULL)); +} + +static void +default_pthread_mutex_init(bionic_mutex_t *mutex) +{ + assert(mutex && !IS_MAPPED(mutex)); + mutex->glibc = mmap(NULL, sizeof(pthread_mutex_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + + for (size_t i = 0; i < ARRAY_SIZE(bionic_mutex_init_map); ++i) { + if (!memcmp(&bionic_mutex_init_map[i].bionic, mutex, sizeof(*mutex))) + continue; + + memcpy(mutex->glibc, &bionic_mutex_init_map[i].glibc, sizeof(bionic_mutex_init_map[i].glibc)); + return; + } + + assert(0 && "no such default initializer???"); +} + +int +bionic_pthread_mutex_lock(bionic_mutex_t *mutex) +{ + assert(mutex); + INIT_IF_NOT_MAPPED(mutex, default_pthread_mutex_init); + return pthread_mutex_lock(mutex->glibc); +} + +int +bionic_pthread_cond_destroy(bionic_cond_t *cond) +{ + assert(cond); + int ret = 0; + if (IS_MAPPED(cond)) { + ret = pthread_cond_destroy(cond->glibc); + munmap(cond->glibc, sizeof(pthread_cond_t)); + } + return ret; +} + +int +bionic_pthread_cond_init(bionic_cond_t *cond, const bionic_condattr_t *attr) +{ + assert(cond && (!attr || IS_MAPPED(attr))); + if (!IS_MAPPED(cond)) + cond->glibc = mmap(NULL, sizeof(pthread_cond_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + return pthread_cond_init(cond->glibc, (attr ? attr->glibc : NULL)); +} + +static void +default_pthread_cond_init(bionic_cond_t *cond) +{ + assert(cond && !IS_MAPPED(cond)); + cond->glibc = mmap(NULL, sizeof(pthread_cond_t), PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_SHARED, -1, 0); + memset(cond->glibc, 0, sizeof(pthread_cond_t)); +} diff --git a/src/linker/NOTICE b/src/linker/NOTICE new file mode 100644 index 0000000..c5b1efa --- /dev/null +++ b/src/linker/NOTICE @@ -0,0 +1,190 @@ + + Copyright (c) 2005-2008, The Android Open Source Project + + Licensed under the Apache License, Version 2.0 (the "License"); + you may not use this file except in compliance with the License. + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + See the License for the specific language governing permissions and + limitations under the License. + + + Apache License + Version 2.0, January 2004 + http://www.apache.org/licenses/ + + TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION + + 1. Definitions. + + "License" shall mean the terms and conditions for use, reproduction, + and distribution as defined by Sections 1 through 9 of this document. + + "Licensor" shall mean the copyright owner or entity authorized by + the copyright owner that is granting the License. + + "Legal Entity" shall mean the union of the acting entity and all + other entities that control, are controlled by, or are under common + control with that entity. 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If You + institute patent litigation against any entity (including a + cross-claim or counterclaim in a lawsuit) alleging that the Work + or a Contribution incorporated within the Work constitutes direct + or contributory patent infringement, then any patent licenses + granted to You under this License for that Work shall terminate + as of the date such litigation is filed. + + 4. Redistribution. You may reproduce and distribute copies of the + Work or Derivative Works thereof in any medium, with or without + modifications, and in Source or Object form, provided that You + meet the following conditions: + + (a) You must give any other recipients of the Work or + Derivative Works a copy of this License; and + + (b) You must cause any modified files to carry prominent notices + stating that You changed the files; and + + (c) You must retain, in the Source form of any Derivative Works + that You distribute, all copyright, patent, trademark, and + attribution notices from the Source form of the Work, + excluding those notices that do not pertain to any part of + the Derivative Works; and + + (d) If the Work includes a "NOTICE" text file as part of its + distribution, then any Derivative Works that You distribute must + include a readable copy of the attribution notices contained + within such NOTICE file, excluding those notices that do not + pertain to any part of the Derivative Works, in at least one + of the following places: within a NOTICE text file distributed + as part of the Derivative Works; within the Source form or + documentation, if provided along with the Derivative Works; or, + within a display generated by the Derivative Works, if and + wherever such third-party notices normally appear. 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In no event and under no legal theory, + whether in tort (including negligence), contract, or otherwise, + unless required by applicable law (such as deliberate and grossly + negligent acts) or agreed to in writing, shall any Contributor be + liable to You for damages, including any direct, indirect, special, + incidental, or consequential damages of any character arising as a + result of this License or out of the use or inability to use the + Work (including but not limited to damages for loss of goodwill, + work stoppage, computer failure or malfunction, or any and all + other commercial damages or losses), even if such Contributor + has been advised of the possibility of such damages. + + 9. Accepting Warranty or Additional Liability. While redistributing + the Work or Derivative Works thereof, You may choose to offer, + and charge a fee for, acceptance of support, warranty, indemnity, + or other liability obligations and/or rights consistent with this + License. However, in accepting such obligations, You may act only + on Your own behalf and on Your sole responsibility, not on behalf + of any other Contributor, and only if You agree to indemnify, + defend, and hold each Contributor harmless for any liability + incurred by, or claims asserted against, such Contributor by reason + of your accepting any such warranty or additional liability. + + END OF TERMS AND CONDITIONS + diff --git a/src/linker/README.TXT b/src/linker/README.TXT new file mode 100644 index 0000000..f920b97 --- /dev/null +++ b/src/linker/README.TXT @@ -0,0 +1,144 @@ +Android Dynamic Linker Design Notes +=================================== + +Introduction: +------------- + +This document provides several notes related to the design of the Android +dynamic linker. + + +Prelinking: +----------- + +System libraries in Android are internally prelinked, which means that +any internal relocations within them are stripped from the corresponding +shared object, in order to reduce size and speed up loading. + +Such libraries can only be loaded at the very specific virtual memory address +they have been prelinked to (during the build process). The list of prelinked +system libraries and their corresponding virtual memory address is found in +the file: + + build/core/prelink-linux-<arch>.map + +It should be updated each time a new system library is added to the +system. + +The prelink step happens at build time, and uses the 'soslim' and 'apriori' +tools: + + - 'apriori' is the real prelink tool which removes relocations from the + shared object, however, it must be given a list of symbols to remove + from the file. + + - 'soslim' is used to find symbols in an executable ELF file + and generate a list that can be passed to 'apriori'. + +By default, these tools are only used to remove internal symbols from +libraries, though they have been designed to allow more aggressive +optimizations (e.g. 'global' prelinking and symbol stripping, which +prevent replacing individual system libraries though). + +You can disable prelinking at build time by modifying your Android.mk with +a line like: + + LOCAL_PRELINK_MODULE := false + + +Initialization and Termination functions: +----------------------------------------- + +The Unix Sys V Binary Interface standard states that an +executable can have the following entries in its .dynamic +section: + + DT_INIT + Points to the address of an initialization function + that must be called when the file is loaded. + + DT_INIT_ARRAY + Points to an array of function addresses that must be + called, in-order, to perform initialization. Some of + the entries in the array can be 0 or -1, and should + be ignored. + + Note: this is generally stored in a .init_array section + + DT_INIT_ARRAYSZ + The size of the DT_INITARRAY, if any + + DT_FINI + Points to the address of a finalization function which + must be called when the file is unloaded or the process + terminated. + + DT_FINI_ARRAY + Same as DT_INITARRAY but for finalizers. Note that the + functions must be called in reverse-order though + + Note: this is generally stored in a .fini_array section + + DT_FINI_ARRAYSZ + Size of FT_FINIARRAY + + DT_PREINIT_ARRAY + An array similar to DT_INIT_ARRAY which must *only* be + present in executables, not shared libraries, which contains + a list of functions that need to be called before any other + initialization function (i.e. DT_INIT and/or DT_INIT_ARRAY) + in the executable or any of its libraries. + + Note: this is generally stored in a .preinit_array section + + DT_PREINIT_ARRAYSZ + The size of DT_PREINIT_ARRAY + +If both a DT_INIT and DT_INITARRAY entry are present, the DT_INIT +function must be called before the DT_INITARRAY functions. + +Consequently, the DT_FINIARRAY must be parsed in reverse order before +the DT_FINI function, if both are available. + +Note that the implementation of static C++ constructors is very +much processor dependent, and may use different ELF sections. + +On the ARM (see "C++ ABI for ARM" document), the static constructors +must be called explicitly from the DT_INIT_ARRAY, and each one of them +shall register a destructor by calling the special __eabi_atexit() +function (provided by the C library). The DT_FINI_ARRAY is not used +by static C++ destructors. + +On x86, the lists of constructors and destructors are placed in special +sections named ".ctors" and ".dtors", and the DT_INIT / DT_FINI functions +are in charge of calling them explicitly. + + +Debugging: +---------- + +It is possible to enable debug output in the dynamic linker. To do so, +follow these steps: + +1/ Modify the line in Android.mk that says: + + LOCAL_CFLAGS += -DLINKER_DEBUG=0 + + Into the following: + + LOCAL_CFLAGS += -DLINKER_DEBUG=1 + +2/ Force-rebuild the dynamic linker: + + cd bionic/linker + mm -B + +3/ Rebuild a new system image. + +You can increase the verbosity of debug traces by defining the DEBUG +environment variable to a numeric value from 0 to 2. This will only +affect new processes being launched. + +By default, traces are sent to logcat, with the "linker" tag. You can +change this to go to stdout instead by setting the definition of +LINKER_DEBUG_TO_LOG to 0 in "linker_debug.h". diff --git a/src/linker/bionic_tls.h b/src/linker/bionic_tls.h new file mode 100644 index 0000000..3907a83 --- /dev/null +++ b/src/linker/bionic_tls.h @@ -0,0 +1,141 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +#ifndef _SYS_TLS_H +#define _SYS_TLS_H + +#define HAVE_ARM_TLS_REGISTER + +#include <sys/cdefs.h> + +__BEGIN_DECLS + +/** WARNING WARNING WARNING + ** + ** This header file is *NOT* part of the public Bionic ABI/API + ** and should not be used/included by user-serviceable parts of + ** the system (e.g. applications). + ** + ** It is only provided here for the benefit of the system dynamic + ** linker and the OpenGL sub-system (which needs to access the + ** pre-allocated slot directly for performance reason). + **/ + +/* maximum number of elements in the TLS array */ +#define BIONIC_TLS_SLOTS 64 + +/* note that slot 0, called TLS_SLOT_SELF must point to itself. + * this is required to implement thread-local storage with the x86 + * Linux kernel, that reads the TLS from fs:[0], where 'fs' is a + * thread-specific segment descriptor... + */ + +/* Well known TLS slots */ +#define TLS_SLOT_SELF 0 +#define TLS_SLOT_THREAD_ID 1 +#define TLS_SLOT_ERRNO 2 + +#define TLS_SLOT_OPENGL_API 3 +#define TLS_SLOT_OPENGL 4 + +/* this slot is only used to pass information from the dynamic linker to + * libc.so when the C library is loaded in to memory. The C runtime init + * function will then clear it. Since its use is extremely temporary, + * we reuse an existing location. + */ +#define TLS_SLOT_BIONIC_PREINIT (TLS_SLOT_ERRNO+1) + +/* small technical note: it is not possible to call pthread_setspecific + * on keys that are <= TLS_SLOT_MAX_WELL_KNOWN, which is why it is set to + * TLS_SLOT_ERRNO. + * + * later slots like TLS_SLOT_OPENGL are pre-allocated through the use of + * TLS_DEFAULT_ALLOC_MAP. this means that there is no need to use + * pthread_key_create() to initialize them. on the other hand, there is + * no destructor associated to them (we might need to implement this later) + */ +#define TLS_SLOT_MAX_WELL_KNOWN TLS_SLOT_ERRNO + +#define TLS_DEFAULT_ALLOC_MAP 0x0000001F + +/* set the Thread Local Storage, must contain at least BIONIC_TLS_SLOTS pointers */ +extern void __init_tls(void** tls, void* thread_info); + +/* syscall only, do not call directly */ +extern int __set_tls(void *ptr); + +/* get the TLS */ +#ifdef __arm__ +/* The standard way to get the TLS is to call a kernel helper + * function (i.e. a function provided at a fixed address in a + * "magic page" mapped in all user-space address spaces ), which + * contains the most appropriate code path for the target device. + * + * However, for performance reasons, we're going to use our own + * machine code for the system's C shared library. + * + * We cannot use this optimization in the static version of the + * C library, because we don't know where the corresponding code + * is going to run. + */ +# ifdef LIBC_STATIC + +/* Use the kernel helper in static C library. */ + typedef volatile void* (__kernel_get_tls_t)(void); +# define __get_tls() (*(__kernel_get_tls_t *)0xffff0fe0)() + +# else /* !LIBC_STATIC */ +/* Use optimized code path. + * Note that HAVE_ARM_TLS_REGISTER is build-specific + * (it must match your kernel configuration) + */ +# ifdef HAVE_ARM_TLS_REGISTER + /* We can read the address directly from a coprocessor + * register, which avoids touching the data cache + * completely. + */ +# define __get_tls() \ + ({ register unsigned int __val asm("r0"); \ + asm ("mrc p15, 0, r0, c13, c0, 3" : "=r"(__val) ); \ + (volatile void*)__val; }) +# else /* !HAVE_ARM_TLS_REGISTER */ + /* The kernel provides the address of the TLS at a fixed + * address of the magic page too. + */ +# define __get_tls() ( *((volatile void **) 0xffff0ff0) ) +# endif +# endif /* !LIBC_STATIC */ +#else /* !ARM */ +extern void* __get_tls( void ); +#endif /* !ARM */ + +/* return the stack base and size, used by our malloc debugger */ +extern void* __get_stack_base(int *p_stack_size); + +__END_DECLS + +#endif /* _SYS_TLS_H */ diff --git a/src/linker/dlfcn.c b/src/linker/dlfcn.c new file mode 100644 index 0000000..3f76e92 --- /dev/null +++ b/src/linker/dlfcn.c @@ -0,0 +1,333 @@ +/* + * Copyright (C) 2007 The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#include <dlfcn.h> +#include <pthread.h> +#include <time.h> +#include <stdio.h> +#include <string.h> +#include "linker.h" +#include "linker_format.h" + +/* for apkenv_get_hooked_symbol */ +// #include "../compat/hooks.h" + +/* for create_wrapper */ +// #include "../debug/wrappers.h" + +#include "linker_debug.h" + +#ifdef APKENV_DEBUG +# define LINKER_DEBUG_PRINTF(...) PRINT(__VA_ARGS__) +#else +# define LINKER_DEBUG_PRINTF(...) +#endif +/* This file hijacks the symbols stubbed out in libdl.so. */ + +#define DL_SUCCESS 0 +#define DL_ERR_CANNOT_LOAD_LIBRARY 1 +#define DL_ERR_INVALID_LIBRARY_HANDLE 2 +#define DL_ERR_BAD_SYMBOL_NAME 3 +#define DL_ERR_SYMBOL_NOT_FOUND 4 +#define DL_ERR_SYMBOL_NOT_GLOBAL 5 + +static char dl_err_buf[1024]; +static const char *dl_err_str; + +static const char *dl_errors[] = { + [DL_ERR_CANNOT_LOAD_LIBRARY] = "Cannot load library", + [DL_ERR_INVALID_LIBRARY_HANDLE] = "Invalid library handle", + [DL_ERR_BAD_SYMBOL_NAME] = "Invalid symbol name", + [DL_ERR_SYMBOL_NOT_FOUND] = "Symbol not found", + [DL_ERR_SYMBOL_NOT_GLOBAL] = "Symbol is not global", +}; + +#define likely(expr) __builtin_expect (expr, 1) +#define unlikely(expr) __builtin_expect (expr, 0) + +pthread_mutex_t apkenv_dl_lock = PTHREAD_MUTEX_INITIALIZER; + +static void set_dlerror(int err) +{ + format_buffer(dl_err_buf, sizeof(dl_err_buf), "%s: %s", dl_errors[err], + apkenv_linker_get_error()); + dl_err_str = (const char *)&dl_err_buf[0]; +} + +void *apkenv_android_dlopen(const char *filename, int flag) +{ + soinfo *ret; + + pthread_mutex_lock(&apkenv_dl_lock); + ret = apkenv_find_library(filename); + + if (unlikely(ret == NULL)) { + set_dlerror(DL_ERR_CANNOT_LOAD_LIBRARY); + } else { + apkenv_call_constructors_recursive(ret); + ret->refcount++; + } + pthread_mutex_unlock(&apkenv_dl_lock); + return ret; +} + +static void *apkenv_android_dlopen_wrap(const char *filename, int flag) +{ +#if 0 + void *ret = get_builtin_lib_handle(filename); + if (ret) + return ret; +#endif + + return apkenv_android_dlopen(filename, flag); +} + +const char *apkenv_android_dlerror(void) +{ + const char *tmp = dl_err_str; + dl_err_str = NULL; + return (const char *)tmp; +} + +enum { + WRAPPER_DYNHOOK, +}; + +void *apkenv_android_dlsym(void *handle, const char *symbol) +{ + soinfo *found; + Elf32_Sym *sym; + unsigned bind; + + pthread_mutex_lock(&apkenv_dl_lock); + + if(unlikely(handle == 0)) { + set_dlerror(DL_ERR_INVALID_LIBRARY_HANDLE); + goto err; + } + if(unlikely(symbol == 0)) { + set_dlerror(DL_ERR_BAD_SYMBOL_NAME); + goto err; + } + +#if 0 + void *sym_addr; + if(0 != (sym_addr = apkenv_get_hooked_symbol_dlfcn(handle, symbol))) + { + LINKER_DEBUG_PRINTF("symbol %s hooked to %x\n",symbol,sym_addr); + pthread_mutex_unlock(&apkenv_dl_lock); + return sym_addr; + } + + if (is_builtin_lib_handle(handle)) { + /* must be hooked.. */ + set_dlerror(DL_ERR_SYMBOL_NOT_FOUND); + goto err; + } +#endif + + if(handle == RTLD_DEFAULT) { + sym = apkenv_lookup(symbol, &found, NULL); + } else if(handle == RTLD_NEXT) { + void *ret_addr = __builtin_return_address(0); + soinfo *si = apkenv_find_containing_library(ret_addr); + + sym = NULL; + if(si && si->next) { + sym = apkenv_lookup(symbol, &found, si->next); + } + } else { + found = (soinfo*)handle; + sym = apkenv_lookup_in_library(found, symbol); + } + + if(likely(sym != 0)) { + bind = ELF32_ST_BIND(sym->st_info); + + if(likely((bind == STB_GLOBAL) && (sym->st_shndx != 0))) { + unsigned ret = sym->st_value + found->base; + pthread_mutex_unlock(&apkenv_dl_lock); + return create_wrapper((char*)symbol, (void*)ret, WRAPPER_DYNHOOK); + } + + set_dlerror(DL_ERR_SYMBOL_NOT_GLOBAL); + } + else + set_dlerror(DL_ERR_SYMBOL_NOT_FOUND); + +err: + LINKER_DEBUG_PRINTF("symbol %s has not been hooked\n",symbol); + pthread_mutex_unlock(&apkenv_dl_lock); + return 0; +} + +int apkenv_android_dladdr(const void *addr, Dl_info *info) +{ + int ret = 0; + + pthread_mutex_lock(&apkenv_dl_lock); + + /* Determine if this address can be found in any library currently mapped */ + soinfo *si = apkenv_find_containing_library(addr); + + if(si) { + memset(info, 0, sizeof(*info)); + + info->dli_fname = si->name; + info->dli_fbase = (void*)(uintptr_t)si->base; + + /* Determine if any symbol in the library contains the specified address */ + Elf32_Sym *sym = apkenv_find_containing_symbol(addr, si); + + if(sym != NULL) { + info->dli_sname = si->strtab + sym->st_name; + info->dli_saddr = (void*)(uintptr_t)(si->base + sym->st_value); + } + + ret = 1; + } + + pthread_mutex_unlock(&apkenv_dl_lock); + + return ret; +} + +int apkenv_android_dlclose(void *handle) +{ +#if 0 + if (is_builtin_lib_handle(handle)) + return 0; +#endif + + pthread_mutex_lock(&apkenv_dl_lock); + (void)apkenv_unload_library((soinfo*)handle); + pthread_mutex_unlock(&apkenv_dl_lock); + return 0; +} + + +#if defined(ANDROID_ARM_LINKER) +// 0000000 00011111 111112 22222222 2333333 333344444444445555555 +// 0123456 78901234 567890 12345678 9012345 678901234567890123456 +#define ANDROID_LIBDL_STRTAB \ + "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0dl_unwind_find_exidx\0" + +_Unwind_Ptr apkenv_android_dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount); + +#elif defined(ANDROID_X86_LINKER) +// 0000000 00011111 111112 22222222 2333333 3333444444444455 +// 0123456 78901234 567890 12345678 9012345 6789012345678901 +#define ANDROID_LIBDL_STRTAB \ + "dlopen\0dlclose\0dlsym\0dlerror\0dladdr\0dl_iterate_phdr\0" +int +apkenv_android_dl_iterate_phdr(int (*cb)(struct dl_phdr_info *info, size_t size, void *data), + void *data); + +#else +#error Unsupported architecture. Only ARM and x86 are presently supported. +#endif + +static Elf32_Sym apkenv_libdl_symtab[7]; + +/* Fake out a hash table with a single bucket. + * A search of the hash table will look through + * apkenv_libdl_symtab starting with index [1], then + * use apkenv_libdl_chains to find the next index to + * look at. apkenv_libdl_chains should be set up to + * walk through every element in apkenv_libdl_symtab, + * and then end with 0 (sentinel value). + * + * I.e., apkenv_libdl_chains should look like + * { 0, 2, 3, ... N, 0 } where N is the number + * of actual symbols, or nelems(apkenv_libdl_symtab)-1 + * (since the first element of apkenv_libdl_symtab is not + * a real symbol). + * + * (see _elf_lookup()) + * + * Note that adding any new symbols here requires + * stubbing them out in libdl. + */ +static unsigned apkenv_libdl_buckets[1] = { 1 }; +static unsigned apkenv_libdl_chains[7] = { 0, 2, 3, 4, 5, 6, 0 }; + +soinfo apkenv_libdl_info = { + .name = "libdl.so", + .flags = FLAG_LINKED, + + .strtab = ANDROID_LIBDL_STRTAB, + .symtab = apkenv_libdl_symtab, + + .nbucket = 1, + .nchain = 7, + .bucket = apkenv_libdl_buckets, + .chain = apkenv_libdl_chains, +}; + +__attribute__((constructor)) +void +construct(void) +{ + const Elf32_Sym symtab[sizeof(apkenv_libdl_symtab) / sizeof(apkenv_libdl_symtab[0])] = { + // total length of apkenv_libdl_info.strtab, including trailing 0 + // This is actually the the STH_UNDEF entry. Technically, it's + // supposed to have st_name == 0, but instead, it points to an index + // in the strtab with a \0 to make iterating through the symtab easier. + { + .st_name = sizeof(ANDROID_LIBDL_STRTAB) - 1, + }, { + .st_name = 0, // starting index of the name in apkenv_libdl_info.strtab + .st_value = (Elf32_Addr)(uintptr_t)apkenv_android_dlopen_wrap, + .st_info = STB_GLOBAL << 4, + .st_shndx = 1, + }, { + .st_name = 7, + .st_value = (Elf32_Addr)(uintptr_t)apkenv_android_dlclose, + .st_info = STB_GLOBAL << 4, + .st_shndx = 1, + }, { + .st_name = 15, + .st_value = (Elf32_Addr)(uintptr_t)apkenv_android_dlsym, + .st_info = STB_GLOBAL << 4, + .st_shndx = 1, + }, { + .st_name = 21, + .st_value = (Elf32_Addr)(uintptr_t)apkenv_android_dlerror, + .st_info = STB_GLOBAL << 4, + .st_shndx = 1, + }, { + .st_name = 29, + .st_value = (Elf32_Addr)(uintptr_t)apkenv_android_dladdr, + .st_info = STB_GLOBAL << 4, + .st_shndx = 1, + }, +#ifdef ANDROID_ARM_LINKER + { + .st_name = 36, + .st_value = (Elf32_Addr)(uintptr_t)apkenv_android_dl_unwind_find_exidx, + .st_info = STB_GLOBAL << 4, + .st_shndx = 1, + }, +#elif defined(ANDROID_X86_LINKER) + { + .st_name = 36, + .st_value = (Elf32_Addr)(uintptr_t)apkenv_android_dl_iterate_phdr, + .st_info = STB_GLOBAL << 4, + .st_shndx = 1, + }, +#endif + }; + memcpy(apkenv_libdl_symtab, symtab, sizeof(symtab)); +} diff --git a/src/linker/linker.c b/src/linker/linker.c new file mode 100644 index 0000000..8f95472 --- /dev/null +++ b/src/linker/linker.c @@ -0,0 +1,2541 @@ +/* + * Copyright (C) 2008, 2009 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifdef APKENV_DEBUG +# define LINKER_DEBUG_PRINTF(...) PRINT(__VA_ARGS__) +#else +# define LINKER_DEBUG_PRINTF(...) +#endif + + +#include <linux/auxvec.h> + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <fcntl.h> +#include <errno.h> +#include <dlfcn.h> +#include <sys/stat.h> +#include <assert.h> + +#include <pthread.h> + +#include <sys/mman.h> + +/* special private C library header - see Android.mk */ +#include "bionic_tls.h" + +#include "strlcpy.h" + +/* for apkenv_get_hooked_symbol */ +// #include "../compat/hooks.h" +/* for create_wrapper */ +// #include "../debug/wrappers.h" + +#include "linker.h" +#include "linker_debug.h" +#include "linker_environ.h" +#include "linker_format.h" + +#define ALLOW_SYMBOLS_FROM_MAIN 1 +#define SO_MAX 128 + +/* Assume average path length of 64 and max 8 paths */ +#define LDPATH_BUFSIZE 512 +#define LDPATH_MAX 8 + +#define LDPRELOAD_BUFSIZE 512 +#define LDPRELOAD_MAX 8 + +/* >>> IMPORTANT NOTE - READ ME BEFORE MODIFYING <<< + * + * Do NOT use malloc() and friends or pthread_*() code here. + * Don't use printf() either; it's caused mysterious memory + * corruption in the past. + * The linker runs before we bring up libc and it's easiest + * to make sure it does not depend on any complex libc features + * + * open issues / todo: + * + * - are we doing everything we should for ARM_COPY relocations? + * - cleaner error reporting + * - after linking, set as much stuff as possible to READONLY + * and NOEXEC + * - linker hardcodes PAGE_SIZE and PAGE_MASK because the kernel + * headers provide versions that are negative... + * - allocate space for soinfo structs dynamically instead of + * having a hard limit (64) +*/ + + +static int apkenv_link_image(soinfo *si, unsigned wr_offset); + +static int apkenv_socount = 0; +static soinfo apkenv_sopool[SO_MAX]; +static soinfo *apkenv_freelist = NULL; +static soinfo *apkenv_solist = &apkenv_libdl_info; +static soinfo *apkenv_sonext = &apkenv_libdl_info; +#if ALLOW_SYMBOLS_FROM_MAIN +static soinfo *apkenv_somain; /* main process, always the one after apkenv_libdl_info */ +#endif + + +static inline int apkenv_validate_soinfo(soinfo *si) +{ + return (si >= apkenv_sopool && si < apkenv_sopool + SO_MAX) || + si == &apkenv_libdl_info; +} + +static char apkenv_ldpaths_buf[LDPATH_BUFSIZE]; +static const char *apkenv_ldpaths[LDPATH_MAX + 1]; + +static char apkenv_ldpreloads_buf[LDPRELOAD_BUFSIZE]; +static const char *apkenv_ldpreload_names[LDPRELOAD_MAX + 1]; + +static soinfo *apkenv_preloads[LDPRELOAD_MAX + 1]; + +#if LINKER_DEBUG +int apkenv_debug_verbosity = 5; +#endif + +static int apkenv_pid; + +/* This boolean is set if the program being loaded is setuid */ +static int apkenv_program_is_setuid; + +#if STATS +struct _link_stats apkenv_linker_stats; +#endif + +#if COUNT_PAGES +unsigned apkenv_bitmask[4096]; +#endif + +#ifndef PT_ARM_EXIDX +#define PT_ARM_EXIDX 0x70000001 /* .ARM.exidx segment */ +#endif + +static char apkenv_tmp_err_buf[768]; +static char apkenv___linker_dl_err_buf[768]; +#define DL_ERR(fmt, x...) \ + do { \ + format_buffer(apkenv___linker_dl_err_buf, sizeof(apkenv___linker_dl_err_buf), \ + "%s[%d]: " fmt, __func__, __LINE__, ##x); \ + ERROR(fmt "\n", ##x); \ + } while(0) + +const char *apkenv_linker_get_error(void) +{ + return (const char *)&apkenv___linker_dl_err_buf[0]; +} + +enum { + WRAPPER_DYNHOOK, + WRAPPER_THUMB_INJECTION, + WRAPPER_UNHOOKED, + WRAPPER_ARM_INJECTION, +}; + +static void +trace(const char *const symbol) +{ + printf("trace: %s\n", symbol); +} + +__asm__( + "wrapper_start: nop\n" + "wrapper_symbol: pushl $0xFAFBFCFD\n" + "wrapper_trace: movl $0xFAFBFCFD, %eax\ncall *%eax\npop %eax\n" + "wrapper_call: movl $0xFAFBFCFD, %eax\njmp *%eax\n" + "wrapper_end: nop\n" +); + +extern char wrapper_start, wrapper_symbol, wrapper_trace, wrapper_call, wrapper_end; + +void* +create_wrapper(const char *const symbol, void *function, int wrapper_type) +{ + const size_t sz = &wrapper_end - &wrapper_start; + unsigned char *fun = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + assert(fun != MAP_FAILED); + memcpy(fun, &wrapper_start, sz); + memcpy(fun + (&wrapper_symbol - &wrapper_start) + 1, &symbol, sizeof(symbol)); + memcpy(fun + (&wrapper_trace - &wrapper_start) + 1, (uintptr_t[]){ (uintptr_t)trace }, sizeof(uintptr_t)); + memcpy(fun + (&wrapper_call - &wrapper_start) + 1, &function, sizeof(function)); + mprotect(fun, sz, PROT_READ | PROT_EXEC); + return fun; +} + +/* + * This function is an empty stub where GDB locates a breakpoint to get notified + * about linker activity. + */ +//extern void __attribute__((noinline)) rtld_db_dlactivity(void); + +//static struct r_debug _r_debug = {1, NULL, &rtld_db_dlactivity, +// RT_CONSISTENT, 0}; +/* apkenv */ +#define rtld_db_dlactivity() ((void (*)(void))_r_debug.r_brk)() + +static struct link_map *apkenv_r_debug_head, *apkenv_r_debug_tail; + +static pthread_mutex_t apkenv__r_debug_lock = PTHREAD_MUTEX_INITIALIZER; + +static void apkenv_insert_soinfo_into_debug_map(soinfo * info) +{ + struct link_map * map; + + /* Copy the necessary fields into the debug structure. + */ + map = &(info->linkmap); + map->l_addr = info->base; + map->l_name = info->fullpath; + map->l_ld = (void *)info->dynamic; + + /* Stick the new library at the end of the list. + * gdb tends to care more about libc than it does + * about leaf libraries, and ordering it this way + * reduces the back-and-forth over the wire. + */ + if (apkenv_r_debug_tail) { + apkenv_r_debug_tail->l_next = map; + map->l_prev = apkenv_r_debug_tail; + map->l_next = 0; + } else { + /* apkenv: for sending to gdb */ + apkenv_r_debug_head = map; + map->l_prev = 0; + map->l_next = 0; + } + apkenv_r_debug_tail = map; +} + +static void apkenv_remove_soinfo_from_debug_map(soinfo * info) +{ + struct link_map * map = &(info->linkmap); + + if (apkenv_r_debug_tail == map) + apkenv_r_debug_tail = map->l_prev; + + if (map->l_prev) map->l_prev->l_next = map->l_next; + if (map->l_next) map->l_next->l_prev = map->l_prev; +} + +void apkenv_notify_gdb_of_libraries(void); + +static void apkenv_notify_gdb_of_load(soinfo * info) +{ + if (info->flags & FLAG_EXE) { + // GDB already knows about the main executable + return; + } + + pthread_mutex_lock(&apkenv__r_debug_lock); + + _r_debug.r_state = RT_ADD; + rtld_db_dlactivity(); + + apkenv_insert_soinfo_into_debug_map(info); + + _r_debug.r_state = RT_CONSISTENT; + rtld_db_dlactivity(); + + apkenv_notify_gdb_of_libraries(); + pthread_mutex_unlock(&apkenv__r_debug_lock); +} + +static void apkenv_notify_gdb_of_unload(soinfo * info) +{ + if (info->flags & FLAG_EXE) { + // GDB already knows about the main executable + return; + } + + pthread_mutex_lock(&apkenv__r_debug_lock); + + _r_debug.r_state = RT_DELETE; + rtld_db_dlactivity(); + + apkenv_remove_soinfo_from_debug_map(info); + + _r_debug.r_state = RT_CONSISTENT; + rtld_db_dlactivity(); + + apkenv_notify_gdb_of_libraries(); + pthread_mutex_unlock(&apkenv__r_debug_lock); +} + +void apkenv_notify_gdb_of_libraries(void) +{ + struct link_map *tmap = _r_debug.r_map; + while (tmap->l_next != NULL) + tmap = tmap->l_next; + + _r_debug.r_state = RT_ADD; + rtld_db_dlactivity(); + + /* append android libs before notifying gdb */ + tmap->l_next = apkenv_r_debug_head; + apkenv_r_debug_head->l_prev = tmap; + + _r_debug.r_state = RT_CONSISTENT; + rtld_db_dlactivity(); + + /* restore so that ld-linux doesn't freak out */ + tmap->l_next = NULL; +} + +static soinfo *apkenv_alloc_info(const char *name) +{ + soinfo *si; + + if(strlen(name) >= SOINFO_NAME_LEN) { + DL_ERR("%5d library name %s too long", apkenv_pid, name); + return NULL; + } + + /* The apkenv_freelist is populated when we call apkenv_free_info(), which in turn is + done only by dlclose(), which is not likely to be used. + */ + if (!apkenv_freelist) { + if(apkenv_socount == SO_MAX) { + DL_ERR("%5d too many libraries when loading %s", apkenv_pid, name); + return NULL; + } + apkenv_freelist = apkenv_sopool + apkenv_socount++; + apkenv_freelist->next = NULL; + } + + si = apkenv_freelist; + apkenv_freelist = apkenv_freelist->next; + + /* Make sure we get a clean block of soinfo */ + memset(si, 0, sizeof(soinfo)); + apkenv_strlcpy((char*) si->name, name, sizeof(si->name)); + apkenv_sonext->next = si; + si->next = NULL; + si->refcount = 0; + apkenv_sonext = si; + + TRACE("%5d name %s: allocated soinfo @ %p\n", apkenv_pid, name, si); + return si; +} + +static void apkenv_free_info(soinfo *si) +{ + soinfo *prev = NULL, *trav; + + TRACE("%5d name %s: freeing soinfo @ %p\n", apkenv_pid, si->name, si); + + for(trav = apkenv_solist; trav != NULL; trav = trav->next){ + if (trav == si) + break; + prev = trav; + } + if (trav == NULL) { + /* si was not ni apkenv_solist */ + DL_ERR("%5d name %s is not in apkenv_solist!", apkenv_pid, si->name); + return; + } + + /* prev will never be NULL, because the first entry in apkenv_solist is + always the static apkenv_libdl_info. + */ + prev->next = si->next; + if (si == apkenv_sonext) apkenv_sonext = prev; + si->next = apkenv_freelist; + apkenv_freelist = si; +} + +static const char *apkenv_addr_to_name(unsigned addr) +{ + soinfo *si; + + for(si = apkenv_solist; si != 0; si = si->next){ + if((addr >= si->base) && (addr < (si->base + si->size))) { + return si->name; + } + } + + return ""; +} + +/* For a given PC, find the .so that it belongs to. + * Returns the base address of the .ARM.exidx section + * for that .so, and the number of 8-byte entries + * in that section (via *pcount). + * + * Intended to be called by libc's __gnu_Unwind_Find_exidx(). + * + * This function is exposed via dlfcn.c and libdl.so. + */ +#ifdef ANDROID_ARM_LINKER +_Unwind_Ptr apkenv_android_dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount) +{ + soinfo *si; + unsigned addr = (unsigned)pc; + + for (si = apkenv_solist; si != 0; si = si->next){ + if ((addr >= si->base) && (addr < (si->base + si->size))) { + *pcount = si->ARM_exidx_count; + return (_Unwind_Ptr)(si->base + (unsigned long)si->ARM_exidx); + } + } + *pcount = 0; + return NULL; +} +#elif defined(ANDROID_X86_LINKER) +/* Here, we only have to provide a callback to iterate across all the + * loaded libraries. gcc_eh does the rest. */ +int +apkenv_android_dl_iterate_phdr(int (*cb)(struct dl_phdr_info *info, size_t size, void *data), + void *data) +{ + soinfo *si; + struct dl_phdr_info dl_info; + int rv = 0; + + for (si = apkenv_solist; si != NULL; si = si->next) { + dl_info.dlpi_addr = si->linkmap.l_addr; + dl_info.dlpi_name = si->linkmap.l_name; + dl_info.dlpi_phdr = (void*)si->phdr; + dl_info.dlpi_phnum = si->phnum; + rv = cb(&dl_info, sizeof (struct dl_phdr_info), data); + if (rv != 0) + break; + } + return rv; +} +#endif + +static Elf32_Sym *apkenv__elf_lookup(soinfo *si, unsigned hash, const char *name) +{ + Elf32_Sym *s; + Elf32_Sym *symtab = si->symtab; + const char *strtab = si->strtab; + unsigned n; + + TRACE_TYPE(LOOKUP, "%5d SEARCH %s in %s@0x%08x %08x %d\n", apkenv_pid, + name, si->name, si->base, hash, hash % si->nbucket); + if (si->nbucket == 0) { + return NULL; + } + n = hash % si->nbucket; + + for(n = si->bucket[hash % si->nbucket]; n != 0; n = si->chain[n]){ + s = symtab + n; + if(strcmp(strtab + s->st_name, name)) continue; + + /* only concern ourselves with global and weak symbol definitions */ + switch(ELF32_ST_BIND(s->st_info)){ + case STB_GLOBAL: + case STB_WEAK: + /* no section == undefined */ + if(s->st_shndx == 0) continue; + + TRACE_TYPE(LOOKUP, "%5d FOUND %s in %s (%08x) %d\n", apkenv_pid, + name, si->name, s->st_value, s->st_size); + return s; + } + } + + return NULL; +} + +static unsigned apkenv_elfhash(const char *_name) +{ + const unsigned char *name = (const unsigned char *) _name; + unsigned h = 0, g; + + while(*name) { + h = (h << 4) + *name++; + g = h & 0xf0000000; + h ^= g; + h ^= g >> 24; + } + return h; +} + +const char *apkenv_last_library_used = NULL; + +static Elf32_Sym * +apkenv__do_lookup(soinfo *si, const char *name, unsigned *base) +{ + unsigned elf_hash = apkenv_elfhash(name); + Elf32_Sym *s; + unsigned *d; + soinfo *lsi = si; + int i; + + /* Look for symbols in the local scope (the object who is + * searching). This happens with C++ templates on i386 for some + * reason. + * + * Notes on weak symbols: + * The ELF specs are ambigious about treatment of weak definitions in + * dynamic linking. Some systems return the first definition found + * and some the first non-weak definition. This is system dependent. + * Here we return the first definition found for simplicity. */ + + s = apkenv__elf_lookup(si, elf_hash, name); + if(s != NULL) + goto done; + + /* Next, look for it in the apkenv_preloads list */ + for(i = 0; apkenv_preloads[i] != NULL; i++) { + lsi = apkenv_preloads[i]; + s = apkenv__elf_lookup(lsi, elf_hash, name); + if(s != NULL) + goto done; + } + + for(d = si->dynamic; *d; d += 2) { + if(d[0] == DT_NEEDED){ + lsi = (soinfo *)d[1]; + if (!apkenv_validate_soinfo(lsi)) { + DL_ERR("%5d bad DT_NEEDED pointer in %s", + apkenv_pid, si->name); + return NULL; + } + + DEBUG("%5d %s: looking up %s in %s\n", + apkenv_pid, si->name, name, lsi->name); + s = apkenv__elf_lookup(lsi, elf_hash, name); + if ((s != NULL) && (s->st_shndx != SHN_UNDEF)) + goto done; + } + } + +#if ALLOW_SYMBOLS_FROM_MAIN + /* If we are resolving relocations while dlopen()ing a library, it's OK for + * the library to resolve a symbol that's defined in the executable itself, + * although this is rare and is generally a bad idea. + */ + if (apkenv_somain) { + lsi = apkenv_somain; + DEBUG("%5d %s: looking up %s in executable %s\n", + apkenv_pid, si->name, name, lsi->name); + s = apkenv__elf_lookup(lsi, elf_hash, name); + } +#endif + +done: + if(s != NULL) { + TRACE_TYPE(LOOKUP, "%5d si %s sym %s s->st_value = 0x%08x, " + "found in %s, base = 0x%08x\n", + apkenv_pid, si->name, name, s->st_value, lsi->name, lsi->base); + apkenv_last_library_used = lsi->name; + *base = lsi->base; + return s; + } + + return NULL; +} + +/* This is used by dl_sym(). It performs symbol lookup only within the + specified soinfo object and not in any of its dependencies. + */ +Elf32_Sym *apkenv_lookup_in_library(soinfo *si, const char *name) +{ + return apkenv__elf_lookup(si, apkenv_elfhash(name), name); +} + +/* This is used by dl_sym(). It performs a global symbol lookup. + */ +Elf32_Sym *apkenv_lookup(const char *name, soinfo **found, soinfo *start) +{ + unsigned elf_hash = apkenv_elfhash(name); + Elf32_Sym *s = NULL; + soinfo *si; + + if(start == NULL) { + start = apkenv_solist; + } + + for(si = start; (s == NULL) && (si != NULL); si = si->next) + { + if(si->flags & FLAG_ERROR) + continue; + s = apkenv__elf_lookup(si, elf_hash, name); + if (s != NULL) { + *found = si; + break; + } + } + + if(s != NULL) { + TRACE_TYPE(LOOKUP, "%5d %s s->st_value = 0x%08x, " + "si->base = 0x%08x\n", apkenv_pid, name, s->st_value, si->base); + return s; + } + + return NULL; +} + +soinfo *apkenv_find_containing_library(const void *addr) +{ + soinfo *si; + + for(si = apkenv_solist; si != NULL; si = si->next) + { + if((unsigned)addr >= si->base && (unsigned)addr - si->base < si->size) { + return si; + } + } + + return NULL; +} + +Elf32_Sym *apkenv_find_containing_symbol(const void *addr, soinfo *si) +{ + unsigned int i; + unsigned soaddr = (unsigned)addr - si->base; + + /* Search the library's symbol table for any defined symbol which + * contains this address */ + for(i=0; i<si->nchain; i++) { + Elf32_Sym *sym = &si->symtab[i]; + + if(sym->st_shndx != SHN_UNDEF && + soaddr >= sym->st_value && + soaddr < sym->st_value + sym->st_size) { + return sym; + } + } + + return NULL; +} + +#if 0 +static void dump(soinfo *si) +{ + Elf32_Sym *s = si->symtab; + unsigned n; + + for(n = 0; n < si->nchain; n++) { + TRACE("%5d %04d> %08x: %02x %04x %08x %08x %s\n", apkenv_pid, n, s, + s->st_info, s->st_shndx, s->st_value, s->st_size, + si->strtab + s->st_name); + s++; + } +} +#endif + +#define SOPATH_MAX 8 + +static const char *apkenv_sopaths[SOPATH_MAX + 1] = { + "/vendor/lib", + "/system/lib", + // APKENV_PREFIX "/lib/" APKENV_TARGET "/bionic/", +#ifdef APKENV_LOCAL_BIONIC_PATH + APKENV_LOCAL_BIONIC_PATH, +#endif +}; + +int apkenv_add_sopath(const char *path) +{ + int i; + for (i = 0; i < SOPATH_MAX; i++) { + if (apkenv_sopaths[i] == NULL) { + apkenv_sopaths[i] = path; + return 0; + } + + if (strcmp(path, apkenv_sopaths[i]) == 0) + return 0; + } + + ERROR("too many apkenv_sopaths\n"); + return -1; +} + +static int apkenv__open_lib(const char *name) +{ + int fd; + struct stat filestat; + + if ((stat(name, &filestat) >= 0) && S_ISREG(filestat.st_mode)) { + if ((fd = open(name, O_RDONLY)) >= 0) + return fd; + } + + return -1; +} + +static int apkenv_open_library(const char *name, char *fullpath) +{ + int fd; + char buf[512]; + const char **path; + int n; + + TRACE("[ %5d opening %s ]\n", apkenv_pid, name); + + if(name == 0) return -1; + if(strlen(name) > 256) return -1; + + strcpy(fullpath, name); + + if ((name[0] == '/') && ((fd = apkenv__open_lib(name)) >= 0)) + return fd; + + if (((fd = apkenv__open_lib(name)) >= 0)) + return fd; + + for (path = apkenv_ldpaths; *path; path++) { + n = format_buffer(buf, sizeof(buf), "%s/%s", *path, name); + if (n < 0 || n >= (int)sizeof(buf)) { + WARN("Ignoring very long library path: %s/%s\n", *path, name); + continue; + } + if ((fd = apkenv__open_lib(buf)) >= 0) { + strcpy(fullpath, buf); + return fd; + } + } + for (path = apkenv_sopaths; *path; path++) { + n = format_buffer(buf, sizeof(buf), "%s/%s", *path, name); + if (n < 0 || n >= (int)sizeof(buf)) { + WARN("Ignoring very long library path: %s/%s\n", *path, name); + continue; + } + if ((fd = apkenv__open_lib(buf)) >= 0) { + strcpy(fullpath, buf); + return fd; + } + } + + return -1; +} + +typedef struct { + long mmap_addr; + char tag[4]; /* 'P', 'R', 'E', ' ' */ +} prelink_info_t; + +/* Returns the requested base address if the library is prelinked, + * and 0 otherwise. */ +static unsigned long +apkenv_is_prelinked(int fd, const char *name) +{ + off_t sz; + prelink_info_t info; + + sz = lseek(fd, -sizeof(prelink_info_t), SEEK_END); + if (sz < 0) { + DL_ERR("lseek() failed!"); + return 0; + } + + if (read(fd, &info, sizeof(info)) != sizeof(info)) { + WARN("Could not read prelink_info_t structure for `%s`\n", name); + return 0; + } + + if (strncmp(info.tag, "PRE ", 4)) { + WARN("`%s` is not a prelinked library\n", name); + return 0; + } + + return (unsigned long)info.mmap_addr; +} + +/* apkenv_verify_elf_object + * Verifies if the object @ base is a valid ELF object + * + * Args: + * + * Returns: + * 0 on success + * -1 if no valid ELF object is found @ base. + */ +static int +apkenv_verify_elf_object(void *base, const char *name) +{ + Elf32_Ehdr *hdr = (Elf32_Ehdr *) base; + + if (hdr->e_ident[EI_MAG0] != ELFMAG0) return -1; + if (hdr->e_ident[EI_MAG1] != ELFMAG1) return -1; + if (hdr->e_ident[EI_MAG2] != ELFMAG2) return -1; + if (hdr->e_ident[EI_MAG3] != ELFMAG3) return -1; + + /* TODO: Should we verify anything else in the header? */ +#ifdef ANDROID_ARM_LINKER + if (hdr->e_machine != EM_ARM) return -1; +#elif defined(ANDROID_X86_LINKER) + if (hdr->e_machine != EM_386) return -1; +#endif + return 0; +} + + +/* apkenv_get_lib_extents + * Retrieves the base (*base) address where the ELF object should be + * mapped and its overall memory size (*total_sz). + * + * Args: + * fd: Opened file descriptor for the library + * name: The name of the library + * _hdr: Pointer to the header page of the library + * total_sz: Total size of the memory that should be allocated for + * this library + * + * Returns: + * -1 if there was an error while trying to get the lib extents. + * The possible reasons are: + * - Could not determine if the library was prelinked. + * - The library provided is not a valid ELF object + * 0 if the library did not request a specific base offset (normal + * for non-prelinked libs) + * > 0 if the library requests a specific address to be mapped to. + * This indicates a pre-linked library. + */ +static unsigned +apkenv_get_lib_extents(int fd, const char *name, void *__hdr, unsigned *total_sz) +{ + unsigned req_base; + unsigned min_vaddr = 0xffffffff; + unsigned max_vaddr = 0; + unsigned char *_hdr = (unsigned char *)__hdr; + Elf32_Ehdr *ehdr = (Elf32_Ehdr *)_hdr; + Elf32_Phdr *phdr; + int cnt; + + TRACE("[ %5d Computing extents for '%s'. ]\n", apkenv_pid, name); + if (apkenv_verify_elf_object(_hdr, name) < 0) { + DL_ERR("%5d - %s is not a valid ELF object", apkenv_pid, name); + return (unsigned)-1; + } + + req_base = (unsigned) apkenv_is_prelinked(fd, name); + if (req_base == (unsigned)-1) + return -1; + else if (req_base != 0) { + TRACE("[ %5d - Prelinked library '%s' requesting base @ 0x%08x ]\n", + apkenv_pid, name, req_base); + } else { + TRACE("[ %5d - Non-prelinked library '%s' found. ]\n", apkenv_pid, name); + } + + phdr = (Elf32_Phdr *)(_hdr + ehdr->e_phoff); + + /* find the min/max p_vaddrs from all the PT_LOAD segments so we can + * get the range. */ + for (cnt = 0; cnt < ehdr->e_phnum; ++cnt, ++phdr) { + if (phdr->p_type == PT_LOAD) { + if ((phdr->p_vaddr + phdr->p_memsz) > max_vaddr) + max_vaddr = phdr->p_vaddr + phdr->p_memsz; + if (phdr->p_vaddr < min_vaddr) + min_vaddr = phdr->p_vaddr; + } + } + + if ((min_vaddr == 0xffffffff) && (max_vaddr == 0)) { + DL_ERR("%5d - No loadable segments found in %s.", apkenv_pid, name); + return (unsigned)-1; + } + + /* truncate min_vaddr down to page boundary */ + min_vaddr &= ~PAGE_MASK; + + /* round max_vaddr up to the next page */ + max_vaddr = (max_vaddr + PAGE_SIZE - 1) & ~PAGE_MASK; + + *total_sz = (max_vaddr - min_vaddr); + return (unsigned)req_base; +} + +/* apkenv_reserve_mem_region + * + * This function reserves a chunk of memory to be used for mapping in + * a prelinked shared library. We reserve the entire memory region here, and + * then the rest of the linker will relocate the individual loadable + * segments into the correct locations within this memory range. + * + * Args: + * si->base: The requested base of the allocation. + * si->size: The size of the allocation. + * + * Returns: + * -1 on failure, and 0 on success. On success, si->base will contain + * the virtual address at which the library will be mapped. + */ + +static int apkenv_reserve_mem_region(soinfo *si) +{ + void *base = mmap((void *)si->base, si->size, PROT_NONE, + MAP_FIXED | MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (base == MAP_FAILED) { + DL_ERR("%5d can NOT map (%sprelinked) library '%s' at 0x%08x " + "as requested, will try general pool: %d (%s)", + apkenv_pid, (si->base ? "" : "non-"), si->name, si->base, + errno, strerror(errno)); + return -1; + } else if (base != (void *)si->base) { + DL_ERR("OOPS: %5d %sprelinked library '%s' mapped at 0x%08x, " + "not at 0x%08x", apkenv_pid, (si->base ? "" : "non-"), + si->name, (unsigned)base, si->base); + munmap(base, si->size); + return -1; + } + return 0; +} + +static int apkenv_alloc_mem_region(soinfo *si) +{ + if (si->base) { + /* Attempt to mmap a prelinked library. */ + return apkenv_reserve_mem_region(si); + } + + /* This is not a prelinked library, so we use the kernel's default + allocator. + */ + + void *base = mmap(NULL, si->size, PROT_NONE, + MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); + if (base == MAP_FAILED) { + DL_ERR("%5d mmap of library '%s' failed: %d (%s)\n", + apkenv_pid, si->name, + errno, strerror(errno)); + goto err; + } + si->base = (unsigned) base; + PRINT("%5d mapped library '%s' to %08x via kernel allocator.\n", + apkenv_pid, si->name, si->base); + return 0; + +err: + DL_ERR("OOPS: %5d cannot map library '%s'. no vspace available.", + apkenv_pid, si->name); + return -1; +} + +#define MAYBE_MAP_FLAG(x,from,to) (((x) & (from)) ? (to) : 0) +#define PFLAGS_TO_PROT(x) (MAYBE_MAP_FLAG((x), PF_X, PROT_EXEC) | \ + MAYBE_MAP_FLAG((x), PF_R, PROT_READ) | \ + MAYBE_MAP_FLAG((x), PF_W, PROT_WRITE)) +/* apkenv_load_segments + * + * This function loads all the loadable (PT_LOAD) segments into memory + * at their appropriate memory offsets off the base address. + * + * Args: + * fd: Open file descriptor to the library to load. + * header: Pointer to a header page that contains the ELF header. + * This is needed since we haven't mapped in the real file yet. + * si: ptr to soinfo struct describing the shared object. + * + * Returns: + * 0 on success, -1 on failure. + */ +static int +apkenv_load_segments(int fd, void *header, soinfo *si) +{ + Elf32_Ehdr *ehdr = (Elf32_Ehdr *)header; + Elf32_Phdr *phdr = (Elf32_Phdr *)((unsigned char *)header + ehdr->e_phoff); + Elf32_Addr base = (Elf32_Addr) si->base; + int cnt; + unsigned len; + Elf32_Addr tmp; + unsigned char *pbase; + unsigned char *extra_base; + unsigned extra_len; + unsigned total_sz = 0; + + si->wrprotect_start = 0xffffffff; + si->wrprotect_end = 0; + + TRACE("[ %5d - Begin loading segments for '%s' @ 0x%08x ]\n", + apkenv_pid, si->name, (unsigned)si->base); + /* Now go through all the PT_LOAD segments and map them into memory + * at the appropriate locations. */ + for (cnt = 0; cnt < ehdr->e_phnum; ++cnt, ++phdr) { + if (phdr->p_type == PT_LOAD) { + DEBUG_DUMP_PHDR(phdr, "PT_LOAD", apkenv_pid); + /* we want to map in the segment on a page boundary */ + tmp = base + (phdr->p_vaddr & (~PAGE_MASK)); + /* add the # of bytes we masked off above to the total length. */ + len = phdr->p_filesz + (phdr->p_vaddr & PAGE_MASK); + + TRACE("[ %d - Trying to load segment from '%s' @ 0x%08x " + "(0x%08x). p_vaddr=0x%08x p_offset=0x%08x ]\n", apkenv_pid, si->name, + (unsigned)tmp, len, phdr->p_vaddr, phdr->p_offset); + pbase = mmap((void *)tmp, len, PFLAGS_TO_PROT(phdr->p_flags), + MAP_PRIVATE | MAP_FIXED, fd, + phdr->p_offset & (~PAGE_MASK)); + if (pbase == MAP_FAILED) { + DL_ERR("%d failed to map segment from '%s' @ 0x%08x (0x%08x). " + "p_vaddr=0x%08x p_offset=0x%08x", apkenv_pid, si->name, + (unsigned)tmp, len, phdr->p_vaddr, phdr->p_offset); + goto fail; + } + + /* If 'len' didn't end on page boundary, and it's a writable + * segment, zero-fill the rest. */ + if ((len & PAGE_MASK) && (phdr->p_flags & PF_W)) + memset((void *)(pbase + len), 0, PAGE_SIZE - (len & PAGE_MASK)); + + /* Check to see if we need to extend the map for this segment to + * cover the diff between filesz and memsz (i.e. for bss). + * + * base _+---------------------+ page boundary + * . . + * | | + * . . + * pbase _+---------------------+ page boundary + * | | + * . . + * base + p_vaddr _| | + * . \ \ . + * . | filesz | . + * pbase + len _| / | | + * <0 pad> . . . + * extra_base _+------------|--------+ page boundary + * / . . . + * | . . . + * | +------------|--------+ page boundary + * extra_len-> | | | | + * | . | memsz . + * | . | . + * \ _| / | + * . . + * | | + * _+---------------------+ page boundary + */ + tmp = (Elf32_Addr)(((unsigned)pbase + len + PAGE_SIZE - 1) & + (~PAGE_MASK)); + if (tmp < (base + phdr->p_vaddr + phdr->p_memsz)) { + extra_len = base + phdr->p_vaddr + phdr->p_memsz - tmp; + TRACE("[ %5d - Need to extend segment from '%s' @ 0x%08x " + "(0x%08x) ]\n", apkenv_pid, si->name, (unsigned)tmp, extra_len); + /* map in the extra page(s) as anonymous into the range. + * This is probably not necessary as we already mapped in + * the entire region previously, but we just want to be + * sure. This will also set the right flags on the region + * (though we can probably accomplish the same thing with + * mprotect). + */ + extra_base = mmap((void *)tmp, extra_len, + PFLAGS_TO_PROT(phdr->p_flags), + MAP_PRIVATE | MAP_FIXED | MAP_ANONYMOUS, + -1, 0); + if (extra_base == MAP_FAILED) { + DL_ERR("[ %5d - failed to extend segment from '%s' @ 0x%08x" + " (0x%08x) ]", apkenv_pid, si->name, (unsigned)tmp, + extra_len); + goto fail; + } + /* TODO: Check if we need to memset-0 this region. + * Anonymous mappings are zero-filled copy-on-writes, so we + * shouldn't need to. */ + TRACE("[ %5d - Segment from '%s' extended @ 0x%08x " + "(0x%08x)\n", apkenv_pid, si->name, (unsigned)extra_base, + extra_len); + } + /* set the len here to show the full extent of the segment we + * just loaded, mostly for debugging */ + len = (((unsigned)base + phdr->p_vaddr + phdr->p_memsz + + PAGE_SIZE - 1) & (~PAGE_MASK)) - (unsigned)pbase; + TRACE("[ %5d - Successfully loaded segment from '%s' @ 0x%08x " + "(0x%08x). p_vaddr=0x%08x p_offset=0x%08x\n", apkenv_pid, si->name, + (unsigned)pbase, len, phdr->p_vaddr, phdr->p_offset); + total_sz += len; + /* Make the section writable just in case we'll have to write to + * it during relocation (i.e. text segment). However, we will + * remember what range of addresses should be write protected. + * + */ + if (!(phdr->p_flags & PF_W)) { + if ((unsigned)pbase < si->wrprotect_start) + si->wrprotect_start = (unsigned)pbase; + if (((unsigned)pbase + len) > si->wrprotect_end) + si->wrprotect_end = (unsigned)pbase + len; + mprotect(pbase, len, + PFLAGS_TO_PROT(phdr->p_flags) | PROT_WRITE); + } + } else if (phdr->p_type == PT_DYNAMIC) { + DEBUG_DUMP_PHDR(phdr, "PT_DYNAMIC", apkenv_pid); + /* this segment contains the dynamic linking information */ + si->dynamic = (unsigned *)(base + phdr->p_vaddr); + } else if (phdr->p_type == PT_GNU_RELRO) { + if ((phdr->p_vaddr >= si->size) + || ((phdr->p_vaddr + phdr->p_memsz) > si->size) + || ((base + phdr->p_vaddr + phdr->p_memsz) < base)) { + DL_ERR("%d invalid GNU_RELRO in '%s' " + "p_vaddr=0x%08x p_memsz=0x%08x", apkenv_pid, si->name, + phdr->p_vaddr, phdr->p_memsz); + goto fail; + } + si->gnu_relro_start = (Elf32_Addr) (base + phdr->p_vaddr); + si->gnu_relro_len = (unsigned) phdr->p_memsz; + } else { +#ifdef ANDROID_ARM_LINKER + if (phdr->p_type == PT_ARM_EXIDX) { + DEBUG_DUMP_PHDR(phdr, "PT_ARM_EXIDX", apkenv_pid); + /* exidx entries (used for stack unwinding) are 8 bytes each. + */ + si->ARM_exidx = (unsigned *)phdr->p_vaddr; + si->ARM_exidx_count = phdr->p_memsz / 8; + } +#endif + } + + } + + /* Sanity check */ + if (total_sz > si->size) { + DL_ERR("%5d - Total length (0x%08x) of mapped segments from '%s' is " + "greater than what was allocated (0x%08x). THIS IS BAD!", + apkenv_pid, total_sz, si->name, si->size); + goto fail; + } + + TRACE("[ %5d - Finish loading segments for '%s' @ 0x%08x. " + "Total memory footprint: 0x%08x bytes ]\n", apkenv_pid, si->name, + (unsigned)si->base, si->size); + return 0; + +fail: + /* We can just blindly unmap the entire region even though some things + * were mapped in originally with anonymous and others could have been + * been mapped in from the file before we failed. The kernel will unmap + * all the pages in the range, irrespective of how they got there. + */ + munmap((void *)si->base, si->size); + si->flags |= FLAG_ERROR; + return -1; +} + +/* TODO: Implement this to take care of the fact that Android ARM + * ELF objects shove everything into a single loadable segment that has the + * write bit set. wr_offset is then used to set non-(data|bss) pages to be + * non-writable. + */ +#if 0 +static unsigned +get_wr_offset(int fd, const char *name, Elf32_Ehdr *ehdr) +{ + Elf32_Shdr *shdr_start; + Elf32_Shdr *shdr; + int shdr_sz = ehdr->e_shnum * sizeof(Elf32_Shdr); + int cnt; + unsigned wr_offset = 0xffffffff; + + shdr_start = mmap(0, shdr_sz, PROT_READ, MAP_PRIVATE, fd, + ehdr->e_shoff & (~PAGE_MASK)); + if (shdr_start == MAP_FAILED) { + WARN("%5d - Could not read section header info from '%s'. Will not " + "not be able to determine write-protect offset.\n", apkenv_pid, name); + return (unsigned)-1; + } + + for(cnt = 0, shdr = shdr_start; cnt < ehdr->e_shnum; ++cnt, ++shdr) { + if ((shdr->sh_type != SHT_NULL) && (shdr->sh_flags & SHF_WRITE) && + (shdr->sh_addr < wr_offset)) { + wr_offset = shdr->sh_addr; + } + } + + munmap(shdr_start, shdr_sz); + return wr_offset; +} +#endif + +static soinfo * +apkenv_load_library(const char *name) +{ + char fullpath[512]; + int fd = apkenv_open_library(name, fullpath); + int cnt; + unsigned ext_sz; + unsigned req_base; + const char *bname; + soinfo *si = NULL; + Elf32_Ehdr *hdr; + + if(fd == -1) { +#if !LINKER_DEBUG + if (!is_lib_optional(name)) +#endif + DL_ERR("Library '%s' not found", name); + return NULL; + } + + off_t end; + if ((end = lseek(fd, 0, SEEK_END)) < 0) { + DL_ERR("lseek() failed!"); + goto fail; + } + + uint8_t *bytes; + if (!(bytes = calloc(1, end))) { + DL_ERR("calloc() failed!"); + goto fail; + } + + /* We have to read the ELF header to figure out what to do with this image + */ + if (lseek(fd, 0, SEEK_SET) < 0) { + DL_ERR("lseek() failed!"); + goto fail; + } + + + if ((cnt = read(fd, bytes, end)) < 0) { + DL_ERR("read() failed!"); + goto fail; + } + + /* Parse the ELF header and get the size of the memory footprint for + * the library */ + req_base = apkenv_get_lib_extents(fd, name, bytes, &ext_sz); + if (req_base == (unsigned)-1) + goto fail; + TRACE("[ %5d - '%s' (%s) wants base=0x%08x sz=0x%08x ]\n", apkenv_pid, name, + (req_base ? "prelinked" : "not pre-linked"), req_base, ext_sz); + + /* Now configure the soinfo struct where we'll store all of our data + * for the ELF object. If the loading fails, we waste the entry, but + * same thing would happen if we failed during linking. Configuring the + * soinfo struct here is a lot more convenient. + */ + bname = strrchr(name, '/'); + si = apkenv_alloc_info(bname ? bname + 1 : name); + if (si == NULL) + goto fail; + + /* apkenv */ + strncpy(si->fullpath, fullpath, sizeof(si->fullpath)); + si->fullpath[sizeof(si->fullpath) - 1] = 0; + + /* Carve out a chunk of memory where we will map in the individual + * segments */ + si->base = req_base; + si->size = ext_sz; + si->flags = 0; + si->entry = 0; + si->dynamic = (unsigned *)-1; + if (apkenv_alloc_mem_region(si) < 0) + goto fail; + + TRACE("[ %5d allocated memory for %s @ %p (0x%08x) ]\n", + apkenv_pid, name, (void *)si->base, (unsigned) ext_sz); + + /* Now actually load the library's segments into right places in memory */ + if (apkenv_load_segments(fd, bytes, si) < 0) { + goto fail; + } + + /* this might not be right. Technically, we don't even need this info + * once we go through 'apkenv_load_segments'. */ + hdr = (Elf32_Ehdr *)si->base; + si->phdr = (Elf32_Phdr *)((unsigned char *)si->base + hdr->e_phoff); + si->phnum = hdr->e_phnum; + /**/ + + close(fd); + return si; + +fail: + if (si) apkenv_free_info(si); + close(fd); + return NULL; +} + +static soinfo * +apkenv_init_library(soinfo *si) +{ + unsigned wr_offset = 0xffffffff; + + /* At this point we know that whatever is loaded @ base is a valid ELF + * shared library whose segments are properly mapped in. */ + TRACE("[ %5d apkenv_init_library base=0x%08x sz=0x%08x name='%s') ]\n", + apkenv_pid, si->base, si->size, si->name); + if(apkenv_link_image(si, wr_offset)) { + /* We failed to link. However, we can only restore libbase + ** if no additional libraries have moved it since we updated it. + */ + munmap((void *)si->base, si->size); + return NULL; + } + + return si; +} + +soinfo *apkenv_find_library(const char *name) +{ + soinfo *si; + const char *bname; + +#if ALLOW_SYMBOLS_FROM_MAIN + if (name == NULL) + return apkenv_somain; +#else + if (name == NULL) + return NULL; +#endif + + bname = strrchr(name, '/'); + bname = bname ? bname + 1 : name; + + for(si = apkenv_solist; si != 0; si = si->next){ + if(!strcmp(bname, si->name)) { + if(si->flags & FLAG_ERROR) { + DL_ERR("%5d '%s' failed to load previously", apkenv_pid, bname); + return NULL; + } + if(si->flags & FLAG_LINKED) return si; + DL_ERR("OOPS: %5d recursive link to '%s'", apkenv_pid, si->name); + return NULL; + } + } + + TRACE("[ %5d '%s' has not been loaded yet. Locating...]\n", apkenv_pid, name); + si = apkenv_load_library(name); + if(si == NULL) + return NULL; + return apkenv_init_library(si); +} + +/* TODO: + * notify gdb of unload + * for non-prelinked libraries, find a way to decrement libbase + */ +static void apkenv_call_destructors(soinfo *si); +unsigned apkenv_unload_library(soinfo *si) +{ + unsigned *d; + if (si->refcount == 1) { + TRACE("%5d unloading '%s'\n", apkenv_pid, si->name); + apkenv_call_destructors(si); + + /* + * Make sure that we undo the PT_GNU_RELRO protections we added + * in apkenv_link_image. This is needed to undo the DT_NEEDED hack below. + */ + if ((si->gnu_relro_start != 0) && (si->gnu_relro_len != 0)) { + Elf32_Addr start = (si->gnu_relro_start & ~PAGE_MASK); + unsigned len = (si->gnu_relro_start - start) + si->gnu_relro_len; + if (mprotect((void *) start, len, PROT_READ | PROT_WRITE) < 0) + DL_ERR("%5d %s: could not undo GNU_RELRO protections. " + "Expect a crash soon. errno=%d (%s)", + apkenv_pid, si->name, errno, strerror(errno)); + + } + + for(d = si->dynamic; *d; d += 2) { + if(d[0] == DT_NEEDED){ + soinfo *lsi = (soinfo *)d[1]; + + // The next line will segfault if the we don't undo the + // PT_GNU_RELRO protections (see comments above and in + // apkenv_link_image(). + d[1] = 0; + + if (apkenv_validate_soinfo(lsi)) { + TRACE("%5d %s needs to unload %s\n", apkenv_pid, + si->name, lsi->name); + apkenv_unload_library(lsi); + } + else + DL_ERR("%5d %s: could not unload dependent library", + apkenv_pid, si->name); + } + } + + munmap((char *)si->base, si->size); + apkenv_notify_gdb_of_unload(si); + apkenv_free_info(si); + si->refcount = 0; + } + else { + si->refcount--; + PRINT("%5d not unloading '%s', decrementing refcount to %d\n", + apkenv_pid, si->name, si->refcount); + } + return si->refcount; +} + +#define MIN(a,b) (((a)<(b))?(a):(b)) + +/* TODO: don't use unsigned for addrs below. It works, but is not + * ideal. They should probably be either uint32_t, Elf32_Addr, or unsigned + * long. + */ +static int apkenv_reloc_library(soinfo *si, Elf32_Rel *rel, unsigned count) +{ + Elf32_Sym *symtab = si->symtab; + const char *strtab = si->strtab; + Elf32_Sym *s; + unsigned base; + Elf32_Rel *start = rel; + unsigned idx; + + for (idx = 0; idx < count; ++idx) { + unsigned type = ELF32_R_TYPE(rel->r_info); + unsigned sym = ELF32_R_SYM(rel->r_info); + unsigned reloc = (unsigned)(rel->r_offset + si->base); + unsigned sym_addr = 0; + char *sym_name = NULL; + char wrap_sym_name[1024] = { 'b', 'i', 'o', 'n', 'i', 'c', '_' }; + + DEBUG("%5d Processing '%s' relocation at index %d\n", apkenv_pid, + si->name, idx); + if(sym != 0) { + sym_name = (char *)(strtab + symtab[sym].st_name); + memcpy(wrap_sym_name + 7, sym_name, MIN(sizeof(wrap_sym_name) - 7, strlen(sym_name))); + sym_addr = 0; + if ((sym_addr = dlsym(RTLD_DEFAULT, wrap_sym_name))) { + LINKER_DEBUG_PRINTF("%s hooked symbol %s to %x\n", si->name, wrap_sym_name, sym_addr); + } else if ((sym_addr = dlsym(RTLD_DEFAULT, sym_name))) { + LINKER_DEBUG_PRINTF("%s hooked symbol %s to %x\n", si->name, sym_name, sym_addr); + } +#if 0 + if ((sym_addr = (unsigned)apkenv_get_hooked_symbol(sym_name, 1)) != 0) { + LINKER_DEBUG_PRINTF("%s hooked symbol %s to %x\n", si->name, sym_name, sym_addr); + } +#endif + else + { + s = apkenv__do_lookup(si, sym_name, &base); + } + if(sym_addr != 0) + { + sym_addr = (unsigned)create_wrapper(sym_name, (void*)sym_addr, WRAPPER_UNHOOKED); + } else + if(s == NULL) { + /* We only allow an undefined symbol if this is a weak + reference.. */ + s = &symtab[sym]; + if (ELF32_ST_BIND(s->st_info) != STB_WEAK) { + DL_ERR("%5d cannot locate '%s'...\n", apkenv_pid, sym_name); + return -1; + } + + /* IHI0044C AAELF 4.5.1.1: + + Libraries are not searched to resolve weak references. + It is not an error for a weak reference to remain + unsatisfied. + + During linking, the value of an undefined weak reference is: + - Zero if the relocation type is absolute + - The address of the place if the relocation is pc-relative + - The address of nominial base address if the relocation + type is base-relative. + */ + + switch (type) { +#if defined(ANDROID_ARM_LINKER) + case R_ARM_JUMP_SLOT: + case R_ARM_GLOB_DAT: + case R_ARM_ABS32: + case R_ARM_RELATIVE: /* Don't care. */ + case R_ARM_NONE: /* Don't care. */ +#elif defined(ANDROID_X86_LINKER) + case R_386_JUMP_SLOT: + case R_386_GLOB_DAT: + case R_386_32: + case R_386_RELATIVE: /* Dont' care. */ +#endif /* ANDROID_*_LINKER */ + /* sym_addr was initialized to be zero above or relocation + code below does not care about value of sym_addr. + No need to do anything. */ + break; + +#if defined(ANDROID_X86_LINKER) + case R_386_PC32: + sym_addr = reloc; + break; +#endif /* ANDROID_X86_LINKER */ + +#if defined(ANDROID_ARM_LINKER) + case R_ARM_COPY: + /* Fall through. Can't really copy if weak symbol is + not found in run-time. */ +#endif /* ANDROID_ARM_LINKER */ + default: + DL_ERR("%5d unknown weak reloc type %d @ %p (%d)\n", + apkenv_pid, type, rel, (int) (rel - start)); + return -1; + } + } else { + /* We got a definition. */ +#if 0 + if((base == 0) && (si->base != 0)){ + /* linking from libraries to main image is bad */ + DL_ERR("%5d cannot locate '%s'...", + apkenv_pid, strtab + symtab[sym].st_name); + return -1; + } +#endif + sym_addr = (unsigned)(s->st_value + base); + LINKER_DEBUG_PRINTF("%s symbol (from %s) %s to %x\n", si->name, apkenv_last_library_used, sym_name, sym_addr); + if(ELF32_ST_TYPE(s->st_info) == STT_FUNC) { + sym_addr = (unsigned)create_wrapper(sym_name, (void*)sym_addr, WRAPPER_UNHOOKED); + } + + } + COUNT_RELOC(RELOC_SYMBOL); + } else { + s = NULL; + } + +/* TODO: This is ugly. Split up the relocations by arch into + * different files. + */ + switch(type){ +#if defined(ANDROID_ARM_LINKER) + case R_ARM_JUMP_SLOT: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO JMP_SLOT %08x <- %08x %s\n", apkenv_pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) = sym_addr; + break; + case R_ARM_GLOB_DAT: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO GLOB_DAT %08x <- %08x %s\n", apkenv_pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) = sym_addr; + break; + case R_ARM_ABS32: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO ABS %08x <- %08x %s\n", apkenv_pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) += sym_addr; + break; + case R_ARM_REL32: + COUNT_RELOC(RELOC_RELATIVE); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO REL32 %08x <- %08x - %08x %s\n", apkenv_pid, + reloc, sym_addr, rel->r_offset, sym_name); + *((unsigned*)reloc) += sym_addr - rel->r_offset; + break; +#elif defined(ANDROID_X86_LINKER) + case R_386_JUMP_SLOT: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO JMP_SLOT %08x <- %08x %s\n", apkenv_pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) = sym_addr; + break; + case R_386_GLOB_DAT: + COUNT_RELOC(RELOC_ABSOLUTE); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO GLOB_DAT %08x <- %08x %s\n", apkenv_pid, + reloc, sym_addr, sym_name); + *((unsigned*)reloc) = sym_addr; + break; +#endif /* ANDROID_*_LINKER */ + +#if defined(ANDROID_ARM_LINKER) + case R_ARM_RELATIVE: +#elif defined(ANDROID_X86_LINKER) + case R_386_RELATIVE: +#endif /* ANDROID_*_LINKER */ + COUNT_RELOC(RELOC_RELATIVE); + MARK(rel->r_offset); + if(sym){ + DL_ERR("%5d odd RELATIVE form...", apkenv_pid); + return -1; + } + TRACE_TYPE(RELO, "%5d RELO RELATIVE %08x <- +%08x\n", apkenv_pid, + reloc, si->base); + *((unsigned*)reloc) += si->base; + break; + +#if defined(ANDROID_X86_LINKER) + case R_386_32: + COUNT_RELOC(RELOC_RELATIVE); + MARK(rel->r_offset); + + TRACE_TYPE(RELO, "%5d RELO R_386_32 %08x <- +%08x %s\n", apkenv_pid, + reloc, sym_addr, sym_name); + *((unsigned *)reloc) += (unsigned)sym_addr; + break; + + case R_386_PC32: + COUNT_RELOC(RELOC_RELATIVE); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO R_386_PC32 %08x <- " + "+%08x (%08x - %08x) %s\n", apkenv_pid, reloc, + (sym_addr - reloc), sym_addr, reloc, sym_name); + *((unsigned *)reloc) += (unsigned)(sym_addr - reloc); + break; +#endif /* ANDROID_X86_LINKER */ + +#ifdef ANDROID_ARM_LINKER + case R_ARM_COPY: + COUNT_RELOC(RELOC_COPY); + MARK(rel->r_offset); + TRACE_TYPE(RELO, "%5d RELO %08x <- %d @ %08x %s\n", apkenv_pid, + reloc, s->st_size, sym_addr, sym_name); + memcpy((void*)reloc, (void*)sym_addr, s->st_size); + break; + case R_ARM_NONE: + break; +#endif /* ANDROID_ARM_LINKER */ + + default: + DL_ERR("%5d unknown reloc type %d @ %p (%d)", + apkenv_pid, type, rel, (int) (rel - start)); + return -1; + } + rel++; + } + return 0; +} + +/* Please read the "Initialization and Termination functions" functions. + * of the linker design note in bionic/linker/README.TXT to understand + * what the following code is doing. + * + * The important things to remember are: + * + * DT_PREINIT_ARRAY must be called first for executables, and should + * not appear in shared libraries. + * + * DT_INIT should be called before DT_INIT_ARRAY if both are present + * + * DT_FINI should be called after DT_FINI_ARRAY if both are present + * + * DT_FINI_ARRAY must be parsed in reverse order. + */ + +static void apkenv_call_array(unsigned *ctor, int count, int reverse) +{ + int n, inc = 1; + + if (reverse) { + ctor += (count-1); + inc = -1; + } + + for(n = count; n > 0; n--) { + TRACE("[ %5d Looking at %s *0x%08x == 0x%08x ]\n", apkenv_pid, + reverse ? "dtor" : "ctor", + (unsigned)ctor, (unsigned)*ctor); + void (*func)() = (void (*)()) *ctor; + ctor += inc; + if(((int) func == 0) || ((int) func == -1)) continue; + TRACE("[ %5d Calling func @ 0x%08x ]\n", apkenv_pid, (unsigned)func); + func(); + } +} + +void apkenv_call_constructors_recursive(soinfo *si) +{ + if (si->constructors_called) + return; + if (strcmp(si->name, "libc.so") == 0) +return; + // Set this before actually calling the constructors, otherwise it doesn't + // protect against recursive constructor calls. One simple example of + // constructor recursion is the libc debug malloc, which is implemented in + // libc_malloc_debug_leak.so: + // 1. The program depends on libc, so libc's constructor is called here. + // 2. The libc constructor calls dlopen() to load libc_malloc_debug_leak.so. + // 3. dlopen() calls apkenv_call_constructors_recursive() with the newly created + // soinfo for libc_malloc_debug_leak.so. + // 4. The debug so depends on libc, so apkenv_call_constructors_recursive() is + // called again with the libc soinfo. If it doesn't trigger the early- + // out above, the libc constructor will be called again (recursively!). + si->constructors_called = 1; + + if (si->flags & FLAG_EXE) { + TRACE("[ %5d Calling preinit_array @ 0x%08x [%d] for '%s' ]\n", + apkenv_pid, (unsigned)si->preinit_array, si->preinit_array_count, + si->name); + apkenv_call_array(si->preinit_array, si->preinit_array_count, 0); + TRACE("[ %5d Done calling preinit_array for '%s' ]\n", apkenv_pid, si->name); + } else { + if (si->preinit_array) { + DL_ERR("%5d Shared library '%s' has a preinit_array table @ 0x%08x." + " This is INVALID.", apkenv_pid, si->name, + (unsigned)si->preinit_array); + } + } + + if (si->dynamic) { + unsigned *d; + for(d = si->dynamic; *d; d += 2) { + if(d[0] == DT_NEEDED){ + soinfo* lsi = (soinfo *)d[1]; + if (!apkenv_validate_soinfo(lsi)) { + DL_ERR("%5d bad DT_NEEDED pointer in %s", + apkenv_pid, si->name); + } else { + apkenv_call_constructors_recursive(lsi); + } + } + } + } + + if (si->init_func) { + TRACE("[ %5d Calling init_func @ 0x%08x for '%s' ]\n", apkenv_pid, + (unsigned)si->init_func, si->name); + si->init_func(); + TRACE("[ %5d Done calling init_func for '%s' ]\n", apkenv_pid, si->name); + } + + if (si->init_array) { + TRACE("[ %5d Calling init_array @ 0x%08x [%d] for '%s' ]\n", apkenv_pid, + (unsigned)si->init_array, si->init_array_count, si->name); + apkenv_call_array(si->init_array, si->init_array_count, 0); + TRACE("[ %5d Done calling init_array for '%s' ]\n", apkenv_pid, si->name); + } + +} + +static void apkenv_call_destructors(soinfo *si) +{ + if (si->fini_array) { + TRACE("[ %5d Calling fini_array @ 0x%08x [%d] for '%s' ]\n", apkenv_pid, + (unsigned)si->fini_array, si->fini_array_count, si->name); + apkenv_call_array(si->fini_array, si->fini_array_count, 1); + TRACE("[ %5d Done calling fini_array for '%s' ]\n", apkenv_pid, si->name); + } + + if (si->fini_func) { + TRACE("[ %5d Calling fini_func @ 0x%08x for '%s' ]\n", apkenv_pid, + (unsigned)si->fini_func, si->name); + si->fini_func(); + TRACE("[ %5d Done calling fini_func for '%s' ]\n", apkenv_pid, si->name); + } +} + +/* Force any of the closed stdin, stdout and stderr to be associated with + /dev/null. */ +static int apkenv_nullify_closed_stdio (void) +{ + int dev_null, i, status; + int return_value = 0; + + dev_null = open("/dev/null", O_RDWR); + if (dev_null < 0) { + DL_ERR("Cannot open /dev/null."); + return -1; + } + TRACE("[ %5d Opened /dev/null file-descriptor=%d]\n", apkenv_pid, dev_null); + + /* If any of the stdio file descriptors is valid and not associated + with /dev/null, dup /dev/null to it. */ + for (i = 0; i < 3; i++) { + /* If it is /dev/null already, we are done. */ + if (i == dev_null) + continue; + + TRACE("[ %5d Nullifying stdio file descriptor %d]\n", apkenv_pid, i); + /* The man page of fcntl does not say that fcntl(..,F_GETFL) + can be interrupted but we do this just to be safe. */ + do { + status = fcntl(i, F_GETFL); + } while (status < 0 && errno == EINTR); + + /* If file is openned, we are good. */ + if (status >= 0) + continue; + + /* The only error we allow is that the file descriptor does not + exist, in which case we dup /dev/null to it. */ + if (errno != EBADF) { + DL_ERR("nullify_stdio: unhandled error %s", strerror(errno)); + return_value = -1; + continue; + } + + /* Try dupping /dev/null to this stdio file descriptor and + repeat if there is a signal. Note that any errors in closing + the stdio descriptor are lost. */ + do { + status = dup2(dev_null, i); + } while (status < 0 && errno == EINTR); + + if (status < 0) { + DL_ERR("nullify_stdio: dup2 error %s", strerror(errno)); + return_value = -1; + continue; + } + } + + /* If /dev/null is not one of the stdio file descriptors, close it. */ + if (dev_null > 2) { + TRACE("[ %5d Closing /dev/null file-descriptor=%d]\n", apkenv_pid, dev_null); + do { + status = close(dev_null); + } while (status < 0 && errno == EINTR); + + if (status < 0) { + DL_ERR("nullify_stdio: close error %s", strerror(errno)); + return_value = -1; + } + } + + return return_value; +} + +static void apkenv_wrap_function(void *sym_addr, char *sym_name, int is_thumb, soinfo *si) +{ + void *hook = NULL; +#ifdef APKENV_LATEHOOKS + if((hook = apkenv_get_hooked_symbol(sym_name, 0)) != NULL) + { + // if we have a hook redirect the call to that by overwriting + // the first 2 instruction of the function + // this should work in any case unless the hook is wrong + // or the function shorter than 64-bit (2 32-Bit instructions) + if(!is_thumb) + { + DEBUG("HOOKING INTERNAL (ARM) FUNCTION %s@%x (in %s) TO: %x\n",sym_name,sym_addr,si->name,hook); + ((int32_t*)sym_addr)[0] = 0xe51ff004; // ldr pc, [pc, -#4] (load the hooks address into pc) + ((int32_t*)sym_addr)[1] = (uint32_t)create_wrapper(sym_name, hook, WRAPPER_LATEHOOK); + + __clear_cache((int32_t*)sym_addr, (int32_t*)sym_addr + 2); + } + else + { + DEBUG("HOOKING INTERNAL (THUMB) FUNCTION %s@%x (in %s) TO: %x\n",sym_name,sym_addr,si->name,hook); + sym_addr = (void*)((char*)sym_addr - 1); // get actual sym_addr + + ((int16_t*)sym_addr)[0] = 0xB401; /* push {r0} */ + ((int16_t*)sym_addr)[1] = 0xF8DF; /* ldr r0, [pc, #8] */ + ((int16_t*)sym_addr)[2] = 0x0008; /* continuation of last instruction */ + ((int16_t*)sym_addr)[3] = 0x4684; /* mov ip, r0 */ + ((int16_t*)sym_addr)[4] = 0xBC01; /* pop {r0} */ + ((int16_t*)sym_addr)[5] = 0x4760; /* bx ip */ + + void *wrp = create_wrapper(sym_name, hook, WRAPPER_LATEHOOK); + + // store the hooks address + ((int16_t*)sym_addr)[6] = (uint32_t)wrp & 0x0000FFFF; + ((int16_t*)sym_addr)[7] = (uint32_t)wrp >> 16; + + __clear_cache((int16_t*)sym_addr, (int16_t*)sym_addr + 8); + } + } + else +#endif /* APKENV_LATEHOOKS */ + // TODO: this will fail if the first 2 instructions do something pc related + // (this DOES NOT happen very often) + if(sym_addr && !is_thumb) + { + DEBUG("CREATING ARM WRAPPER FOR: %s@%x (in %s)\n", sym_name, (unsigned)sym_addr, si->name); + + create_wrapper(sym_name, sym_addr, WRAPPER_ARM_INJECTION); + } + // TODO: this will fail if the first 2-5 instructions do something pc related + // (this DOES happen very often) + else if(sym_addr && is_thumb) + { + DEBUG("CREATING THUMB WRAPPER FOR: %s@%x (in %s)\n",sym_name, (unsigned)sym_addr,si->name); + + create_wrapper(sym_name, sym_addr, WRAPPER_THUMB_INJECTION); + } +} + + +/* Franz-Josef Haider apkenv_create_latehook_wrappers */ +static void apkenv_create_latehook_wrappers(soinfo *si) +{ + Elf32_Sym *s; + + unsigned int n = 0; + for(n=0;n<si->nchain;n++) + { + s = si->symtab + n; + switch(ELF32_ST_BIND(s->st_info)) + { + case STB_GLOBAL: + case STB_WEAK: + if(s->st_shndx == 0) continue; + + if(ELF32_ST_TYPE(s->st_info) == STT_FUNC) // only wrap functions + { + char *sym_name = (char*)(si->strtab + s->st_name); + void *sym_addr = (void*)(intptr_t)(si->base + s->st_value); + + int is_thumb = ((int32_t)(intptr_t)sym_addr) & 0x00000001; + + apkenv_wrap_function(sym_addr,sym_name,is_thumb,si); + } + } + } +} + + +static int apkenv_link_image(soinfo *si, unsigned wr_offset) +{ + unsigned *d; + Elf32_Phdr *phdr = si->phdr; + int phnum = si->phnum; + + INFO("[ %5d linking %s ]\n", apkenv_pid, si->name); + DEBUG("%5d si->base = 0x%08x si->flags = 0x%08x\n", apkenv_pid, + si->base, si->flags); + + if (si->flags & (FLAG_EXE | FLAG_LINKER)) { + /* Locate the needed program segments (DYNAMIC/ARM_EXIDX) for + * linkage info if this is the executable or the linker itself. + * If this was a dynamic lib, that would have been done at load time. + * + * TODO: It's unfortunate that small pieces of this are + * repeated from the apkenv_load_library routine. Refactor this just + * slightly to reuse these bits. + */ + si->size = 0; + for(; phnum > 0; --phnum, ++phdr) { +#ifdef ANDROID_ARM_LINKER + if(phdr->p_type == PT_ARM_EXIDX) { + /* exidx entries (used for stack unwinding) are 8 bytes each. + */ + si->ARM_exidx = (unsigned *)phdr->p_vaddr; + si->ARM_exidx_count = phdr->p_memsz / 8; + } +#endif + if (phdr->p_type == PT_LOAD) { + /* For the executable, we use the si->size field only in + dl_unwind_find_exidx(), so the meaning of si->size + is not the size of the executable; it is the distance + between the load location of the executable and the last + address of the loadable part of the executable. + We use the range [si->base, si->base + si->size) to + determine whether a PC value falls within the executable + section. Of course, if a value is between si->base and + (si->base + phdr->p_vaddr), it's not in the executable + section, but a) we shouldn't be asking for such a value + anyway, and b) if we have to provide an EXIDX for such a + value, then the executable's EXIDX is probably the better + choice. + */ + DEBUG_DUMP_PHDR(phdr, "PT_LOAD", apkenv_pid); + if (phdr->p_vaddr + phdr->p_memsz > si->size) + si->size = phdr->p_vaddr + phdr->p_memsz; + /* try to remember what range of addresses should be write + * protected */ + if (!(phdr->p_flags & PF_W)) { + unsigned _end; + + if (si->base + phdr->p_vaddr < si->wrprotect_start) + si->wrprotect_start = si->base + phdr->p_vaddr; + _end = (((si->base + phdr->p_vaddr + phdr->p_memsz + PAGE_SIZE - 1) & + (~PAGE_MASK))); + if (_end > si->wrprotect_end) + si->wrprotect_end = _end; + /* Make the section writable just in case we'll have to + * write to it during relocation (i.e. text segment). + * However, we will remember what range of addresses + * should be write protected. + */ + mprotect((void *) (si->base + phdr->p_vaddr), + phdr->p_memsz, + PFLAGS_TO_PROT(phdr->p_flags) | PROT_WRITE); + } + } else if (phdr->p_type == PT_DYNAMIC) { + if (si->dynamic != (unsigned *)-1) { + DL_ERR("%5d multiple PT_DYNAMIC segments found in '%s'. " + "Segment at 0x%08x, previously one found at 0x%08x", + apkenv_pid, si->name, si->base + phdr->p_vaddr, + (unsigned)si->dynamic); + goto fail; + } + DEBUG_DUMP_PHDR(phdr, "PT_DYNAMIC", apkenv_pid); + si->dynamic = (unsigned *) (si->base + phdr->p_vaddr); + } else if (phdr->p_type == PT_GNU_RELRO) { + if ((phdr->p_vaddr >= si->size) + || ((phdr->p_vaddr + phdr->p_memsz) > si->size) + || ((si->base + phdr->p_vaddr + phdr->p_memsz) < si->base)) { + DL_ERR("%d invalid GNU_RELRO in '%s' " + "p_vaddr=0x%08x p_memsz=0x%08x", apkenv_pid, si->name, + phdr->p_vaddr, phdr->p_memsz); + goto fail; + } + si->gnu_relro_start = (Elf32_Addr) (si->base + phdr->p_vaddr); + si->gnu_relro_len = (unsigned) phdr->p_memsz; + } + } + } + + if (si->dynamic == (unsigned *)-1) { + DL_ERR("%5d missing PT_DYNAMIC?!", apkenv_pid); + goto fail; + } + + DEBUG("%5d dynamic = %p\n", apkenv_pid, si->dynamic); + + /* extract useful information from dynamic section */ + for(d = si->dynamic; *d; d++){ + DEBUG("%5d d = %p, d[0] = 0x%08x d[1] = 0x%08x\n", apkenv_pid, d, d[0], d[1]); + switch(*d++){ + case DT_HASH: + si->nbucket = ((unsigned *) (si->base + *d))[0]; + si->nchain = ((unsigned *) (si->base + *d))[1]; + si->bucket = (unsigned *) (si->base + *d + 8); + si->chain = (unsigned *) (si->base + *d + 8 + si->nbucket * 4); + break; + case DT_STRTAB: + si->strtab = (const char *) (si->base + *d); + break; + case DT_SYMTAB: + si->symtab = (Elf32_Sym *) (si->base + *d); + break; + case DT_PLTREL: + if(*d != DT_REL) { + DL_ERR("DT_RELA not supported"); + goto fail; + } + break; + case DT_JMPREL: + si->plt_rel = (Elf32_Rel*) (si->base + *d); + break; + case DT_PLTRELSZ: + si->plt_rel_count = *d / 8; + break; + case DT_REL: + si->rel = (Elf32_Rel*) (si->base + *d); + break; + case DT_RELSZ: + si->rel_count = *d / 8; + break; + case DT_PLTGOT: + /* Save this in case we decide to do lazy binding. We don't yet. */ + si->plt_got = (unsigned *)(si->base + *d); + break; + case DT_DEBUG: + // Set the DT_DEBUG entry to the addres of _r_debug for GDB + *d = (int) &_r_debug; + break; + case DT_RELA: + DL_ERR("%5d DT_RELA not supported", apkenv_pid); + goto fail; + case DT_INIT: + si->init_func = (void (*)(void))(si->base + *d); + DEBUG("%5d %s constructors (init func) found at %p\n", + apkenv_pid, si->name, si->init_func); + break; + case DT_FINI: + si->fini_func = (void (*)(void))(si->base + *d); + DEBUG("%5d %s destructors (fini func) found at %p\n", + apkenv_pid, si->name, si->fini_func); + break; + case DT_INIT_ARRAY: + si->init_array = (unsigned *)(si->base + *d); + DEBUG("%5d %s constructors (init_array) found at %p\n", + apkenv_pid, si->name, si->init_array); + break; + case DT_INIT_ARRAYSZ: + si->init_array_count = ((unsigned)*d) / sizeof(Elf32_Addr); + break; + case DT_FINI_ARRAY: + si->fini_array = (unsigned *)(si->base + *d); + DEBUG("%5d %s destructors (fini_array) found at %p\n", + apkenv_pid, si->name, si->fini_array); + break; + case DT_FINI_ARRAYSZ: + si->fini_array_count = ((unsigned)*d) / sizeof(Elf32_Addr); + break; + case DT_PREINIT_ARRAY: + si->preinit_array = (unsigned *)(si->base + *d); + DEBUG("%5d %s constructors (preinit_array) found at %p\n", + apkenv_pid, si->name, si->preinit_array); + break; + case DT_PREINIT_ARRAYSZ: + si->preinit_array_count = ((unsigned)*d) / sizeof(Elf32_Addr); + break; + case DT_TEXTREL: + /* TODO: make use of this. */ + /* this means that we might have to write into where the text + * segment was loaded during relocation... Do something with + * it. + */ + DEBUG("%5d Text segment should be writable during relocation.\n", + apkenv_pid); + break; + } + } + + DEBUG("%5d si->base = 0x%08x, si->strtab = %p, si->symtab = %p\n", + apkenv_pid, si->base, si->strtab, si->symtab); + + if((si->strtab == 0) || (si->symtab == 0)) { + DL_ERR("%5d missing essential tables", apkenv_pid); + goto fail; + } + + /* if this is the main executable, then load all of the apkenv_preloads now */ + if(si->flags & FLAG_EXE) { + int i; + memset(apkenv_preloads, 0, sizeof(apkenv_preloads)); + for(i = 0; apkenv_ldpreload_names[i] != NULL; i++) { + soinfo *lsi = apkenv_find_library(apkenv_ldpreload_names[i]); + if(lsi == 0) { + apkenv_strlcpy(apkenv_tmp_err_buf, apkenv_linker_get_error(), sizeof(apkenv_tmp_err_buf)); + DL_ERR("%5d could not load needed library '%s' for '%s' (%s)", + apkenv_pid, apkenv_ldpreload_names[i], si->name, apkenv_tmp_err_buf); + goto fail; + } + lsi->refcount++; + apkenv_preloads[i] = lsi; + } + } + + for(d = si->dynamic; *d; d += 2) { + if(d[0] == DT_NEEDED){ + DEBUG("%5d %s needs %s\n", apkenv_pid, si->name, si->strtab + d[1]); + soinfo *lsi = NULL; +#if 1 + // if (get_builtin_lib_handle(si->strtab + d[1]) == NULL) + lsi = apkenv_find_library(si->strtab + d[1]); + if (!lsi && dlopen(si->strtab + d[1], RTLD_NOW | RTLD_GLOBAL)) { + DEBUG("Loaded %s with glibc dlopen\n", si->strtab + d[1]); + } +#endif + if(lsi == 0) { + /** + * XXX Dirty Hack Alarm --thp XXX + * + * For libraries that are not found, simply use libdl's soinfo, + * in order to not break downstream users of the library while + * still allowing the application to start up. + **/ + lsi = &apkenv_libdl_info; + //apkenv_strlcpy(apkenv_tmp_err_buf, apkenv_linker_get_error(), sizeof(apkenv_tmp_err_buf)); + //DL_ERR("%5d could not load needed library '%s' for '%s' (%s)", + // apkenv_pid, si->strtab + d[1], si->name, apkenv_tmp_err_buf); + //continue; + //goto fail; + } + /* Save the soinfo of the loaded DT_NEEDED library in the payload + of the DT_NEEDED entry itself, so that we can retrieve the + soinfo directly later from the dynamic segment. This is a hack, + but it allows us to map from DT_NEEDED to soinfo efficiently + later on when we resolve relocations, trying to look up a symbol + with dlsym(). + */ + d[1] = (intptr_t)lsi; + lsi->refcount++; + } + } + + if(si->plt_rel) { + DEBUG("[ %5d relocating %s plt ]\n", apkenv_pid, si->name ); + if(apkenv_reloc_library(si, si->plt_rel, si->plt_rel_count)) + goto fail; + } + if(si->rel) { + DEBUG("[ %5d relocating %s ]\n", apkenv_pid, si->name ); + if(apkenv_reloc_library(si, si->rel, si->rel_count)) + goto fail; + } + + apkenv_create_latehook_wrappers(si); + + si->flags |= FLAG_LINKED; + DEBUG("[ %5d finished linking %s ]\n", apkenv_pid, si->name); + +#if 0 + /* This is the way that the old dynamic linker did protection of + * non-writable areas. It would scan section headers and find where + * .text ended (rather where .data/.bss began) and assume that this is + * the upper range of the non-writable area. This is too coarse, + * and is kept here for reference until we fully move away from single + * segment elf objects. See the code in get_wr_offset (also #if'd 0) + * that made this possible. + */ + if(wr_offset < 0xffffffff){ + mprotect((void*) si->base, wr_offset, PROT_READ | PROT_EXEC); + } +#else + /* TODO: Verify that this does the right thing in all cases, as it + * presently probably does not. It is possible that an ELF image will + * come with multiple read-only segments. What we ought to do is scan + * the program headers again and mprotect all the read-only segments. + * To prevent re-scanning the program header, we would have to build a + * list of loadable segments in si, and then scan that instead. */ + if (si->wrprotect_start != 0xffffffff && si->wrprotect_end != 0) { + mprotect((void *)(intptr_t)si->wrprotect_start, + si->wrprotect_end - si->wrprotect_start, + PROT_READ | PROT_EXEC); + } +#endif + + if (si->gnu_relro_start != 0 && si->gnu_relro_len != 0) { + Elf32_Addr start = (si->gnu_relro_start & ~PAGE_MASK); + unsigned len = (si->gnu_relro_start - start) + si->gnu_relro_len; + if (mprotect((void *)(intptr_t)start, len, PROT_READ) < 0) { + DL_ERR("%5d GNU_RELRO mprotect of library '%s' failed: %d (%s)\n", + apkenv_pid, si->name, errno, strerror(errno)); + goto fail; + } + } + + /* If this is a SET?ID program, dup /dev/null to opened stdin, + stdout and stderr to close a security hole described in: + + ftp://ftp.freebsd.org/pub/FreeBSD/CERT/advisories/FreeBSD-SA-02:23.stdio.asc + + */ + if (apkenv_program_is_setuid) + apkenv_nullify_closed_stdio (); + apkenv_notify_gdb_of_load(si); + return 0; + +fail: + ERROR("failed to link %s\n", si->name); + si->flags |= FLAG_ERROR; + return -1; +} + +void apkenv_parse_library_path(const char *path, char *delim) +{ + size_t len; + char *apkenv_ldpaths_bufp = apkenv_ldpaths_buf; + int i = 0; + + len = apkenv_strlcpy(apkenv_ldpaths_buf, path, sizeof(apkenv_ldpaths_buf)); + + while (i < LDPATH_MAX && (apkenv_ldpaths[i] = strsep(&apkenv_ldpaths_bufp, delim))) { + if (*apkenv_ldpaths[i] != '\0') + ++i; + } + + /* Forget the last path if we had to truncate; this occurs if the 2nd to + * last char isn't '\0' (i.e. not originally a delim). */ + if (i > 0 && len >= sizeof(apkenv_ldpaths_buf) && + apkenv_ldpaths_buf[sizeof(apkenv_ldpaths_buf) - 2] != '\0') { + apkenv_ldpaths[i - 1] = NULL; + } else { + apkenv_ldpaths[i] = NULL; + } +} + +static void apkenv_parse_apkenv_preloads(const char *path, char *delim) +{ + size_t len; + char *apkenv_ldpreloads_bufp = apkenv_ldpreloads_buf; + int i = 0; + + len = apkenv_strlcpy(apkenv_ldpreloads_buf, path, sizeof(apkenv_ldpreloads_buf)); + + while (i < LDPRELOAD_MAX && (apkenv_ldpreload_names[i] = strsep(&apkenv_ldpreloads_bufp, delim))) { + if (*apkenv_ldpreload_names[i] != '\0') { + ++i; + } + } + + /* Forget the last path if we had to truncate; this occurs if the 2nd to + * last char isn't '\0' (i.e. not originally a delim). */ + if (i > 0 && len >= sizeof(apkenv_ldpreloads_buf) && + apkenv_ldpreloads_buf[sizeof(apkenv_ldpreloads_buf) - 2] != '\0') { + apkenv_ldpreload_names[i - 1] = NULL; + } else { + apkenv_ldpreload_names[i] = NULL; + } +} + +/* + * This code is called after the linker has linked itself and + * fixed it's own GOT. It is safe to make references to externs + * and other non-local data at this point. + */ +static unsigned apkenv___linker_init_post_relocation(unsigned **elfdata) +{ + static soinfo linker_soinfo; + + int argc = (int)(intptr_t)*elfdata; + char **argv = (char**) (elfdata + 1); + unsigned *vecs = (unsigned*) (argv + argc + 1); + unsigned *v; + soinfo *si; + struct link_map * map; + const char *ldpath_env = NULL; + const char *ldpreload_env = NULL; + + /* NOTE: we store the elfdata pointer on a special location + * of the temporary TLS area in order to pass it to + * the C Library's runtime initializer. + * + * The initializer must clear the slot and reset the TLS + * to point to a different location to ensure that no other + * shared library constructor can access it. + */ +#if 0 + __libc_init_tls(elfdata); +#endif + + apkenv_pid = getpid(); + +#if TIMING + struct timeval t0, t1; + gettimeofday(&t0, 0); +#endif + + /* Initialize environment functions, and get to the ELF aux vectors table */ + vecs = apkenv_linker_env_init(vecs); + + /* Check auxv for AT_SECURE first to see if program is setuid, setgid, + has file caps, or caused a SELinux/AppArmor domain transition. */ + for (v = vecs; v[0]; v += 2) { + if (v[0] == AT_SECURE) { + /* kernel told us whether to enable secure mode */ + apkenv_program_is_setuid = v[1]; + goto sanitize; + } + } + + /* Kernel did not provide AT_SECURE - fall back on legacy test. */ + apkenv_program_is_setuid = (getuid() != geteuid()) || (getgid() != getegid()); + +sanitize: + /* Sanitize environment if we're loading a setuid program */ + if (apkenv_program_is_setuid) + apkenv_linker_env_secure(); + +#if 0 + apkenv_debugger_init(); +#endif + + /* Get a few environment variables */ + { +#if LINKER_DEBUG + const char* env; + env = apkenv_linker_env_get("DEBUG"); /* XXX: TODO: Change to LD_DEBUG */ + if (env) + apkenv_debug_verbosity = atoi(env); +#endif + + /* Normally, these are cleaned by linker_env_secure, but the test + * against apkenv_program_is_setuid doesn't cost us anything */ + if (!apkenv_program_is_setuid) { + ldpath_env = getenv("LD_LIBRARY_PATH"); + ldpreload_env = getenv("LD_PRELOAD"); + } + } + + INFO("[ android linker & debugger ]\n"); + DEBUG("%5d elfdata @ 0x%08x\n", apkenv_pid, (unsigned)elfdata); + + si = apkenv_alloc_info(argv[0]); + if(si == 0) { + exit(-1); + } + + /* bootstrap the link map, the main exe always needs to be first */ + si->flags |= FLAG_EXE; + map = &(si->linkmap); + + map->l_addr = 0; + map->l_name = argv[0]; + map->l_prev = NULL; + map->l_next = NULL; + + _r_debug.r_map = map; + apkenv_r_debug_tail = map; + + /* gdb expects the linker to be in the debug shared object list, + * and we need to make sure that the reported load address is zero. + * Without this, gdb gets the wrong idea of where rtld_db_dlactivity() + * is. Don't use apkenv_alloc_info(), because the linker shouldn't + * be on the soinfo list. + */ + apkenv_strlcpy((char*) linker_soinfo.name, "/system/bin/linker", sizeof linker_soinfo.name); + linker_soinfo.flags = 0; + linker_soinfo.base = 0; // This is the important part; must be zero. + apkenv_insert_soinfo_into_debug_map(&linker_soinfo); + + /* extract information passed from the kernel */ + while(vecs[0] != 0){ + switch(vecs[0]){ + case AT_PHDR: + si->phdr = (Elf32_Phdr*)(intptr_t)vecs[1]; + break; + case AT_PHNUM: + si->phnum = (int) vecs[1]; + break; + case AT_ENTRY: + si->entry = vecs[1]; + break; + } + vecs += 2; + } + + /* Compute the value of si->base. We can't rely on the fact that + * the first entry is the PHDR because this will not be true + * for certain executables (e.g. some in the NDK unit test suite) + */ + int nn; + si->base = 0; + for ( nn = 0; nn < si->phnum; nn++ ) { + if (si->phdr[nn].p_type == PT_PHDR) { + si->base = (Elf32_Addr)(intptr_t)si->phdr - si->phdr[nn].p_vaddr; + break; + } + } + si->dynamic = (unsigned *)-1; + si->wrprotect_start = 0xffffffff; + si->wrprotect_end = 0; + si->refcount = 1; + si->gnu_relro_start = 0; + si->gnu_relro_len = 0; + + /* Use LD_LIBRARY_PATH if we aren't setuid/setgid */ + if (ldpath_env) + apkenv_parse_library_path(ldpath_env, ":"); + + if (ldpreload_env) { + apkenv_parse_apkenv_preloads(ldpreload_env, " :"); + } + if(apkenv_link_image(si, 0)) { + char errmsg[] = "CANNOT LINK EXECUTABLE\n"; + write(2, apkenv___linker_dl_err_buf, strlen(apkenv___linker_dl_err_buf)); + write(2, errmsg, sizeof(errmsg)); + exit(-1); + } + + apkenv_call_constructors_recursive(si); + +#if ALLOW_SYMBOLS_FROM_MAIN + /* Set apkenv_somain after we've loaded all the libraries in order to prevent + * linking of symbols back to the main image, which is not set up at that + * point yet. + */ + apkenv_somain = si; +#endif + +#if TIMING + gettimeofday(&t1,NULL); + PRINT("LINKER TIME: %s: %d microseconds\n", argv[0], (int) ( + (((long long)t1.tv_sec * 1000000LL) + (long long)t1.tv_usec) - + (((long long)t0.tv_sec * 1000000LL) + (long long)t0.tv_usec) + )); +#endif +#if STATS + PRINT("RELO STATS: %s: %d abs, %d rel, %d copy, %d symbol\n", argv[0], + apkenv_linker_stats.reloc[RELOC_ABSOLUTE], + apkenv_linker_stats.reloc[RELOC_RELATIVE], + apkenv_linker_stats.reloc[RELOC_COPY], + apkenv_linker_stats.reloc[RELOC_SYMBOL]); +#endif +#if COUNT_PAGES + { + unsigned n; + unsigned i; + unsigned count = 0; + for(n = 0; n < 4096; n++){ + if(apkenv_bitmask[n]){ + unsigned x = apkenv_bitmask[n]; + for(i = 0; i < 8; i++){ + if(x & 1) count++; + x >>= 1; + } + } + } + PRINT("PAGES MODIFIED: %s: %d (%dKB)\n", argv[0], count, count * 4); + } +#endif + +#if TIMING || STATS || COUNT_PAGES + fflush(stdout); +#endif + + TRACE("[ %5d Ready to execute '%s' @ 0x%08x ]\n", apkenv_pid, si->name, + si->entry); + return si->entry; +} + +/* + * Find the value of AT_BASE passed to us by the kernel. This is the load + * location of the linker. + */ +static unsigned apkenv_find_linker_base(unsigned **elfdata) { + int argc = (int)(intptr_t)*elfdata; + char **argv = (char**) (elfdata + 1); + unsigned *vecs = (unsigned*) (argv + argc + 1); + while (vecs[0] != 0) { + vecs++; + } + + /* The end of the environment block is marked by two NULL pointers */ + vecs++; + + while(vecs[0]) { + if (vecs[0] == AT_BASE) { + return vecs[1]; + } + vecs += 2; + } + + return 0; // should never happen +} + +/* + * This is the entry point for the linker, called from begin.S. This + * method is responsible for fixing the linker's own relocations, and + * then calling apkenv___linker_init_post_relocation(). + * + * Because this method is called before the linker has fixed it's own + * relocations, any attempt to reference an extern variable, extern + * function, or other GOT reference will generate a segfault. + */ +unsigned apkenv___linker_init(unsigned **elfdata) { + unsigned linker_addr = apkenv_find_linker_base(elfdata); + Elf32_Ehdr *elf_hdr = (Elf32_Ehdr *)(intptr_t)linker_addr; + Elf32_Phdr *phdr = + (Elf32_Phdr *)((unsigned char *)(intptr_t)linker_addr + elf_hdr->e_phoff); + + soinfo linker_so; + memset(&linker_so, 0, sizeof(soinfo)); + + linker_so.base = linker_addr; + linker_so.dynamic = (unsigned *) -1; + linker_so.phdr = phdr; + linker_so.phnum = elf_hdr->e_phnum; + linker_so.flags |= FLAG_LINKER; + linker_so.wrprotect_start = 0xffffffff; + linker_so.wrprotect_end = 0; + linker_so.gnu_relro_start = 0; + linker_so.gnu_relro_len = 0; + if (apkenv_link_image(&linker_so, 0)) { + // It would be nice to print an error message, but if the linker + // can't link itself, there's no guarantee that we'll be able to + // call write() (because it involves a GOT reference). + // + // This situation should never occur unless the linker itself + // is corrupt. + exit(-1); + } + + // We have successfully fixed our own relocations. It's safe to run + // the main part of the linker now. + return apkenv___linker_init_post_relocation(elfdata); +} diff --git a/src/linker/linker.h b/src/linker/linker.h new file mode 100644 index 0000000..13d9bff --- /dev/null +++ b/src/linker/linker.h @@ -0,0 +1,226 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _LINKER_H_ +#define _LINKER_H_ + +#include <unistd.h> +#include <sys/types.h> +#include <elf.h> +#include <link.h> + +#undef PAGE_MASK +#undef PAGE_SIZE +#define PAGE_SIZE 4096 +#define PAGE_MASK 4095 + +void apkenv_debugger_init(); + +/* magic shared structures that GDB knows about */ + +#if 0 +struct link_map +{ + uintptr_t l_addr; + char * l_name; + uintptr_t l_ld; + struct link_map * l_next; + struct link_map * l_prev; +}; + +/* needed for dl_iterate_phdr to be passed to the callbacks provided */ +struct dl_phdr_info +{ + Elf32_Addr dlpi_addr; + const char *dlpi_name; + const Elf32_Phdr *dlpi_phdr; + Elf32_Half dlpi_phnum; +}; + + +// Values for r_debug->state +enum { + RT_CONSISTENT, + RT_ADD, + RT_DELETE +}; + +struct r_debug +{ + int32_t r_version; + struct link_map * r_map; + void (*r_brk)(void); + int32_t r_state; + uintptr_t r_ldbase; +}; +#endif + +typedef struct soinfo soinfo; + +#define FLAG_LINKED 0x00000001 +#define FLAG_ERROR 0x00000002 +#define FLAG_EXE 0x00000004 // The main executable +#define FLAG_LINKER 0x00000010 // The linker itself + +#define SOINFO_NAME_LEN 128 + +struct soinfo +{ + const char name[SOINFO_NAME_LEN]; + Elf32_Phdr *phdr; + int phnum; + unsigned entry; + unsigned base; + unsigned size; + + int unused; // DO NOT USE, maintained for compatibility. + + unsigned *dynamic; + + unsigned wrprotect_start; + unsigned wrprotect_end; + + soinfo *next; + unsigned flags; + + const char *strtab; + Elf32_Sym *symtab; + + unsigned nbucket; + unsigned nchain; + unsigned *bucket; + unsigned *chain; + + unsigned *plt_got; + + Elf32_Rel *plt_rel; + unsigned plt_rel_count; + + Elf32_Rel *rel; + unsigned rel_count; + + unsigned *preinit_array; + unsigned preinit_array_count; + + unsigned *init_array; + unsigned init_array_count; + unsigned *fini_array; + unsigned fini_array_count; + + void (*init_func)(void); + void (*fini_func)(void); + +#ifdef ANDROID_ARM_LINKER + /* ARM EABI section used for stack unwinding. */ + unsigned *ARM_exidx; + unsigned ARM_exidx_count; +#endif + + unsigned refcount; + struct link_map linkmap; + + int constructors_called; + + Elf32_Addr gnu_relro_start; + unsigned gnu_relro_len; + + /* apkenv stuff */ + char fullpath[SOINFO_NAME_LEN]; +}; + + +extern soinfo apkenv_libdl_info; + +#ifdef ANDROID_ARM_LINKER + +#define R_ARM_COPY 20 +#define R_ARM_GLOB_DAT 21 +#define R_ARM_JUMP_SLOT 22 +#define R_ARM_RELATIVE 23 + +/* According to the AAPCS specification, we only + * need the above relocations. However, in practice, + * the following ones turn up from time to time. + */ +#define R_ARM_ABS32 2 +#define R_ARM_REL32 3 + +#elif defined(ANDROID_X86_LINKER) + +#define R_386_32 1 +#define R_386_PC32 2 +#define R_386_GLOB_DAT 6 +#define R_386_JUMP_SLOT 7 +#define R_386_RELATIVE 8 + +#endif + +#ifndef DT_INIT_ARRAY +#define DT_INIT_ARRAY 25 +#endif + +#ifndef DT_FINI_ARRAY +#define DT_FINI_ARRAY 26 +#endif + +#ifndef DT_INIT_ARRAYSZ +#define DT_INIT_ARRAYSZ 27 +#endif + +#ifndef DT_FINI_ARRAYSZ +#define DT_FINI_ARRAYSZ 28 +#endif + +#ifndef DT_PREINIT_ARRAY +#define DT_PREINIT_ARRAY 32 +#endif + +#ifndef DT_PREINIT_ARRAYSZ +#define DT_PREINIT_ARRAYSZ 33 +#endif + +soinfo *apkenv_find_library(const char *name); +unsigned apkenv_unload_library(soinfo *si); +Elf32_Sym *apkenv_lookup_in_library(soinfo *si, const char *name); +Elf32_Sym *apkenv_lookup(const char *name, soinfo **found, soinfo *start); +soinfo *apkenv_find_containing_library(const void *addr); +Elf32_Sym *apkenv_find_containing_symbol(const void *addr, soinfo *si); +const char *apkenv_linker_get_error(void); +void apkenv_call_constructors_recursive(soinfo *si); + +#ifdef ANDROID_ARM_LINKER +typedef long unsigned int *_Unwind_Ptr; +_Unwind_Ptr apkenv_dl_unwind_find_exidx(_Unwind_Ptr pc, int *pcount); +#elif defined(ANDROID_X86_LINKER) +int apkenv_dl_iterate_phdr(int (*cb)(struct dl_phdr_info *, size_t, void *), void *); +#endif + +void apkenv_notify_gdb_of_libraries(void); +int apkenv_add_sopath(const char *path); + +#endif diff --git a/src/linker/linker_debug.h b/src/linker/linker_debug.h new file mode 100644 index 0000000..2ab7a40 --- /dev/null +++ b/src/linker/linker_debug.h @@ -0,0 +1,154 @@ +/* + * Copyright (C) 2008-2010 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#ifndef _LINKER_DEBUG_H_ +#define _LINKER_DEBUG_H_ + +#include <stdio.h> + +#ifndef LINKER_DEBUG +#error LINKER_DEBUG should be defined to either 1 or 0 in Android.mk +#endif + +/* set LINKER_DEBUG_TO_LOG to 1 to send the logs to logcat, + * or 0 to use stdout instead. + */ +#define LINKER_DEBUG_TO_LOG 0 +#define TRACE_DEBUG 1 +#define DO_TRACE_LOOKUP 1 +#define DO_TRACE_RELO 1 +#define TIMING 0 +#define STATS 0 +#define COUNT_PAGES 0 + +/********************************************************************* + * You shouldn't need to modify anything below unless you are adding + * more debugging information. + * + * To enable/disable specific debug options, change the defines above + *********************************************************************/ + + +/*********************************************************************/ +#undef TRUE +#undef FALSE +#define TRUE 1 +#define FALSE 0 + +/* Only use printf() during debugging. We have seen occasional memory + * corruption when the linker uses printf(). + */ +#if LINKER_DEBUG +#include "linker_format.h" +extern int apkenv_debug_verbosity; +#if LINKER_DEBUG_TO_LOG +extern int apkenv_format_log(int, const char *, const char *, ...); +#define _PRINTVF(v,f,x...) \ + do { \ + if (apkenv_debug_verbosity > (v)) apkenv_format_log(5-(v),"linker",x); \ + } while (0) +#else /* !LINKER_DEBUG_TO_LOG */ +#define _PRINTVF(v,f,x...) \ + do { \ + if (apkenv_debug_verbosity > (v)) printf(x); \ + } while (0) +#endif /* !LINKER_DEBUG_TO_LOG */ +#else /* !LINKER_DEBUG */ +#define _PRINTVF(v,f,x...) do {} while(0) +#endif /* LINKER_DEBUG */ + +#define PRINT(x...) _PRINTVF(-1, FALSE, x) +#define INFO(x...) _PRINTVF(1, TRUE, x) +#define TRACE(x...) _PRINTVF(1, TRUE, x) +#define WARN(fmt,args...) \ + _PRINTVF(-1, TRUE, "%s:%d| WARNING: " fmt, __FILE__, __LINE__, ## args) +#define ERROR(fmt,args...) \ + printf("%s:%d| ERROR: " fmt, __FILE__, __LINE__, ## args) + + +#if TRACE_DEBUG +#define DEBUG(x...) _PRINTVF(2, TRUE, "DEBUG: " x) +#else /* !TRACE_DEBUG */ +#define DEBUG(x...) do {} while (0) +#endif /* TRACE_DEBUG */ + +#if LINKER_DEBUG +#define TRACE_TYPE(t,x...) do { if (DO_TRACE_##t) { TRACE(x); } } while (0) +#else /* !LINKER_DEBUG */ +#define TRACE_TYPE(t,x...) do {} while (0) +#endif /* LINKER_DEBUG */ + +#if STATS +#define RELOC_ABSOLUTE 0 +#define RELOC_RELATIVE 1 +#define RELOC_COPY 2 +#define RELOC_SYMBOL 3 +#define NUM_RELOC_STATS 4 + +struct _link_stats { + int reloc[NUM_RELOC_STATS]; +}; +extern struct _link_stats apkenv_linker_stats; + +#define COUNT_RELOC(type) \ + do { if (type >= 0 && type < NUM_RELOC_STATS) { \ + apkenv_linker_stats.reloc[type] += 1; \ + } else { \ + PRINT("Unknown reloc stat requested\n"); \ + } \ + } while(0) +#else /* !STATS */ +#define COUNT_RELOC(type) do {} while(0) +#endif /* STATS */ + +#if TIMING +#undef WARN +#define WARN(x...) do {} while (0) +#endif /* TIMING */ + +#if COUNT_PAGES +extern unsigned apkenv_bitmask[]; +#define MARK(offset) do { \ + apkenv_bitmask[((offset) >> 12) >> 3] |= (1 << (((offset) >> 12) & 7)); \ + } while(0) +#else +#define MARK(x) do {} while (0) +#endif + +#define DEBUG_DUMP_PHDR(phdr, name, pid) do { \ + DEBUG("%5d %s (phdr = 0x%08x)\n", (pid), (name), (unsigned)(phdr)); \ + DEBUG("\t\tphdr->offset = 0x%08x\n", (unsigned)((phdr)->p_offset)); \ + DEBUG("\t\tphdr->p_vaddr = 0x%08x\n", (unsigned)((phdr)->p_vaddr)); \ + DEBUG("\t\tphdr->p_paddr = 0x%08x\n", (unsigned)((phdr)->p_paddr)); \ + DEBUG("\t\tphdr->p_filesz = 0x%08x\n", (unsigned)((phdr)->p_filesz)); \ + DEBUG("\t\tphdr->p_memsz = 0x%08x\n", (unsigned)((phdr)->p_memsz)); \ + DEBUG("\t\tphdr->p_flags = 0x%08x\n", (unsigned)((phdr)->p_flags)); \ + DEBUG("\t\tphdr->p_align = 0x%08x\n", (unsigned)((phdr)->p_align)); \ + } while (0) + +#endif /* _LINKER_DEBUG_H_ */ diff --git a/src/linker/linker_environ.c b/src/linker/linker_environ.c new file mode 100644 index 0000000..ca8b1d9 --- /dev/null +++ b/src/linker/linker_environ.c @@ -0,0 +1,204 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +#include "linker_environ.h" +#include <stddef.h> + +static char** apkenv__envp; + +/* Returns 1 if 'str' points to a valid environment variable definition. + * For now, we check that: + * - It is smaller than MAX_ENV_LEN (to detect non-zero terminated strings) + * - It contains at least one equal sign that is not the first character + */ +static int +apkenv__is_valid_definition(const char* str) +{ + int pos = 0; + int first_equal_pos = -1; + + /* According to its sources, the kernel uses 32*PAGE_SIZE by default + * as the maximum size for an env. variable definition. + */ + const int MAX_ENV_LEN = 32*4096; + + if (str == NULL) + return 0; + + /* Parse the string, looking for the first '=' there, and its size */ + do { + if (str[pos] == '\0') + break; + if (str[pos] == '=' && first_equal_pos < 0) + first_equal_pos = pos; + pos++; + } while (pos < MAX_ENV_LEN); + + if (pos >= MAX_ENV_LEN) /* Too large */ + return 0; + + if (first_equal_pos < 1) /* No equal sign, or it is the first character */ + return 0; + + return 1; +} + +unsigned* +apkenv_linker_env_init(unsigned* vecs) +{ + /* Store environment pointer - can't be NULL */ + apkenv__envp = (char**) vecs; + + /* Skip over all definitions */ + while (vecs[0] != 0) + vecs++; + /* The end of the environment block is marked by two NULL pointers */ + vecs++; + + /* As a sanity check, we're going to remove all invalid variable + * definitions from the environment array. + */ + { + char** readp = apkenv__envp; + char** writep = apkenv__envp; + for ( ; readp[0] != NULL; readp++ ) { + if (!apkenv__is_valid_definition(readp[0])) + continue; + writep[0] = readp[0]; + writep++; + } + writep[0] = NULL; + } + + /* Return the address of the aux vectors table */ + return vecs; +} + +/* Check if the environment variable definition at 'envstr' + * starts with '<name>=', and if so return the address of the + * first character after the equal sign. Otherwise return NULL. + */ +static char* +apkenv_env_match(char* envstr, const char* name) +{ + size_t cnt = 0; + + while (envstr[cnt] == name[cnt] && name[cnt] != '\0') + cnt++; + + if (name[cnt] == '\0' && envstr[cnt] == '=') + return envstr + cnt + 1; + + return NULL; +} + +#define MAX_ENV_LEN (16*4096) + +const char* +apkenv_linker_env_get(const char* name) +{ + char** readp = apkenv__envp; + + if (name == NULL || name[0] == '\0') + return NULL; + + for ( ; readp[0] != NULL; readp++ ) { + char* val = apkenv_env_match(readp[0], name); + if (val != NULL) { + /* Return NULL for empty strings, or if it is too large */ + if (val[0] == '\0') + val = NULL; + return val; + } + } + return NULL; +} + + +void +apkenv_linker_env_unset(const char* name) +{ + char** readp = apkenv__envp; + char** writep = readp; + + if (name == NULL || name[0] == '\0') + return; + + for ( ; readp[0] != NULL; readp++ ) { + if (apkenv_env_match(readp[0], name)) + continue; + writep[0] = readp[0]; + writep++; + } + /* end list with a NULL */ + writep[0] = NULL; +} + + + +/* Remove unsafe environment variables. This should be used when + * running setuid programs. */ +void +apkenv_linker_env_secure(void) +{ + /* The same list than GLibc at this point */ + static const char* const unsec_vars[] = { + "GCONV_PATH", + "GETCONF_DIR", + "HOSTALIASES", + "LD_AUDIT", + "LD_DEBUG", + "LD_DEBUG_OUTPUT", + "LD_DYNAMIC_WEAK", + "LD_LIBRARY_PATH", + "LD_ORIGIN_PATH", + "LD_PRELOAD", + "LD_PROFILE", + "LD_SHOW_AUXV", + "LD_USE_LOAD_BIAS", + "LOCALDOMAIN", + "LOCPATH", + "MALLOC_TRACE", + "MALLOC_CHECK_", + "NIS_PATH", + "NLSPATH", + "RESOLV_HOST_CONF", + "RES_OPTIONS", + "TMPDIR", + "TZDIR", + "LD_AOUT_LIBRARY_PATH", + "LD_AOUT_PRELOAD", + }; + + const char* const* cp = unsec_vars; + const char* const* endp = cp + sizeof(unsec_vars)/sizeof(unsec_vars[0]); + + while (cp < endp) { + apkenv_linker_env_unset(*cp); + cp++; + } +} diff --git a/src/linker/linker_environ.h b/src/linker/linker_environ.h new file mode 100644 index 0000000..9bb24c4 --- /dev/null +++ b/src/linker/linker_environ.h @@ -0,0 +1,54 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +#ifndef LINKER_ENVIRON_H +#define LINKER_ENVIRON_H + +/* Call this function before anything else. 'vecs' must be the pointer + * to the environment block in the ELF data block. The function returns + * the start of the aux vectors after the env block. + */ +extern unsigned* apkenv_linker_env_init(unsigned* vecs); + +/* Unset a given environment variable. In case the variable is defined + * multiple times, unset all instances. This modifies the environment + * block, so any pointer returned by linker_env_get() after this call + * might become invalid */ +extern void apkenv_linker_env_unset(const char* name); + + +/* Returns the value of environment variable 'name' if defined and not + * empty, or NULL otherwise. Note that the returned pointer may become + * invalid if linker_env_unset() or linker_env_secure() are called + * after this function. */ +extern const char* apkenv_linker_env_get(const char* name); + +/* Remove unsecure environment variables. This should be used when + * running setuid programs. */ +extern void apkenv_linker_env_secure(void); + +#endif /* LINKER_ENVIRON_H */ diff --git a/src/linker/linker_format.h b/src/linker/linker_format.h new file mode 100644 index 0000000..e7b34b5 --- /dev/null +++ b/src/linker/linker_format.h @@ -0,0 +1,43 @@ +/* + * Copyright (C) 2010 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ +#ifndef _LINKER_FORMAT_H +#define _LINKER_FORMAT_H + +#include <stdarg.h> +#include <stddef.h> + +/* Formatting routines for the dynamic linker's debug traces */ +/* We want to avoid dragging the whole C library fprintf() */ +/* implementation into the dynamic linker since this creates */ +/* issues (it uses malloc()/free()) and increases code size */ + +// apkenv: we can just use snprintf +//int format_buffer(char *buffer, size_t bufsize, const char *format, ...); +#define format_buffer snprintf + +#endif /* _LINKER_FORMAT_H */ diff --git a/src/linker/rt.c b/src/linker/rt.c new file mode 100644 index 0000000..31db8ee --- /dev/null +++ b/src/linker/rt.c @@ -0,0 +1,36 @@ +/* + * Copyright (C) 2008 The Android Open Source Project + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, + * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT + * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * This function is an empty stub where GDB locates a breakpoint to get notified + * about linker activity. + */ +void __attribute__((noinline)) apkenv_rtld_db_dlactivity(void) +{ +} + diff --git a/src/linker/strlcpy.c b/src/linker/strlcpy.c new file mode 100644 index 0000000..e0fd250 --- /dev/null +++ b/src/linker/strlcpy.c @@ -0,0 +1,50 @@ +/* $OpenBSD: strlcpy.c,v 1.11 2006/05/05 15:27:38 millert Exp $ */ + +/* + * Copyright (c) 1998 Todd C. Miller <Todd.Miller@courtesan.com> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#include "strlcpy.h" + +/* + * Copy src to string dst of size siz. At most siz-1 characters + * will be copied. Always NUL terminates (unless siz == 0). + * Returns strlen(src); if retval >= siz, truncation occurred. + */ +size_t +apkenv_strlcpy(char *dst, const char *src, size_t siz) +{ + char *d = dst; + const char *s = src; + size_t n = siz; + + /* Copy as many bytes as will fit */ + if (n != 0) { + while (--n != 0) { + if ((*d++ = *s++) == '\0') + break; + } + } + + /* Not enough room in dst, add NUL and traverse rest of src */ + if (n == 0) { + if (siz != 0) + *d = '\0'; /* NUL-terminate dst */ + while (*s++) + ; + } + + return(s - src - 1); /* count does not include NUL */ +} diff --git a/src/linker/strlcpy.h b/src/linker/strlcpy.h new file mode 100644 index 0000000..a524530 --- /dev/null +++ b/src/linker/strlcpy.h @@ -0,0 +1,10 @@ +#ifndef STRLCPY_H +#define STRLCPY_H + +#include <sys/types.h> +#include <string.h> + +size_t +apkenv_strlcpy(char *dst, const char *src, size_t siz); + +#endif |