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authorAndrew Gregory <andrew.gregory.8@gmail.com>2014-08-06 16:36:00 -0400
committerAllan McRae <allan@archlinux.org>2014-09-23 21:43:16 +1000
commitc792262b137a5f2daddac22f82e7d8d98d0d7d31 (patch)
treed3177e6c722a96da72503a912d4c5fded0ef78e8
parent9c066dff439ba453f4c362e1875b794cf3f362ed (diff)
wrap fgets to retry on EINTR
The read() underlying fgets() can be interrupted by a signal handler causing fgets() to return NULL. Before we started handling SIGWINCH, the odds of interrupting a read were low and typically resulted in termination anyway. Replace all fgets calls with a wrapper that retries in EINTR. Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>
-rw-r--r--lib/libalpm/be_local.c14
-rw-r--r--lib/libalpm/trans.c2
-rw-r--r--lib/libalpm/util.c3
-rw-r--r--src/common/util-common.c25
-rw-r--r--src/common/util-common.h3
-rw-r--r--src/pacman/ini.c2
-rw-r--r--src/pacman/util.c8
7 files changed, 43 insertions, 14 deletions
diff --git a/lib/libalpm/be_local.c b/lib/libalpm/be_local.c
index 1b333e44..091ed4c8 100644
--- a/lib/libalpm/be_local.c
+++ b/lib/libalpm/be_local.c
@@ -616,7 +616,7 @@ char *_alpm_local_db_pkgpath(alpm_db_t *db, alpm_pkg_t *info,
}
#define READ_NEXT() do { \
- if(fgets(line, sizeof(line), fp) == NULL && !feof(fp)) goto error; \
+ if(safe_fgets(line, sizeof(line), fp) == NULL && !feof(fp)) goto error; \
_alpm_strip_newline(line, 0); \
} while(0)
@@ -627,7 +627,7 @@ char *_alpm_local_db_pkgpath(alpm_db_t *db, alpm_pkg_t *info,
#define READ_AND_STORE_ALL(f) do { \
char *linedup; \
- if(fgets(line, sizeof(line), fp) == NULL) {\
+ if(safe_fgets(line, sizeof(line), fp) == NULL) {\
if(!feof(fp)) goto error; else break; \
} \
if(_alpm_strip_newline(line, 0) == 0) break; \
@@ -636,7 +636,7 @@ char *_alpm_local_db_pkgpath(alpm_db_t *db, alpm_pkg_t *info,
} while(1) /* note the while(1) and not (0) */
#define READ_AND_SPLITDEP(f) do { \
- if(fgets(line, sizeof(line), fp) == NULL) {\
+ if(safe_fgets(line, sizeof(line), fp) == NULL) {\
if(!feof(fp)) goto error; else break; \
} \
if(_alpm_strip_newline(line, 0) == 0) break; \
@@ -682,7 +682,7 @@ static int local_db_read(alpm_pkg_t *info, alpm_dbinfrq_t inforeq)
}
free(path);
while(!feof(fp)) {
- if(fgets(line, sizeof(line), fp) == NULL && !feof(fp)) {
+ if(safe_fgets(line, sizeof(line), fp) == NULL && !feof(fp)) {
goto error;
}
if(_alpm_strip_newline(line, 0) == 0) {
@@ -771,13 +771,13 @@ static int local_db_read(alpm_pkg_t *info, alpm_dbinfrq_t inforeq)
goto error;
}
free(path);
- while(fgets(line, sizeof(line), fp)) {
+ while(safe_fgets(line, sizeof(line), fp)) {
_alpm_strip_newline(line, 0);
if(strcmp(line, "%FILES%") == 0) {
size_t files_count = 0, files_size = 0, len;
alpm_file_t *files = NULL;
- while(fgets(line, sizeof(line), fp) &&
+ while(safe_fgets(line, sizeof(line), fp) &&
(len = _alpm_strip_newline(line, 0))) {
if(!_alpm_greedy_grow((void **)&files, &files_size,
(files_size ? files_size + sizeof(alpm_file_t) : 8 * sizeof(alpm_file_t)))) {
@@ -797,7 +797,7 @@ static int local_db_read(alpm_pkg_t *info, alpm_dbinfrq_t inforeq)
info->files.count = files_count;
info->files.files = files;
} else if(strcmp(line, "%BACKUP%") == 0) {
- while(fgets(line, sizeof(line), fp) && _alpm_strip_newline(line, 0)) {
+ while(safe_fgets(line, sizeof(line), fp) && _alpm_strip_newline(line, 0)) {
alpm_backup_t *backup;
CALLOC(backup, 1, sizeof(alpm_backup_t), goto error);
if(_alpm_split_backup(line, &backup)) {
diff --git a/lib/libalpm/trans.c b/lib/libalpm/trans.c
index 4a176086..aebd8dd2 100644
--- a/lib/libalpm/trans.c
+++ b/lib/libalpm/trans.c
@@ -280,7 +280,7 @@ static int grep(const char *fn, const char *needle)
}
while(!feof(fp)) {
char line[1024];
- if(fgets(line, sizeof(line), fp) == NULL) {
+ if(safe_fgets(line, sizeof(line), fp) == NULL) {
continue;
}
/* TODO: this will not work if the search string
diff --git a/lib/libalpm/util.c b/lib/libalpm/util.c
index 6dab0de2..43d0d7be 100644
--- a/lib/libalpm/util.c
+++ b/lib/libalpm/util.c
@@ -576,8 +576,9 @@ int _alpm_run_chroot(alpm_handle_t *handle, const char *cmd, char *const argv[])
.type = ALPM_EVENT_SCRIPTLET_INFO,
.line = line
};
- if(fgets(line, PATH_MAX, pipe_file) == NULL)
+ if(safe_fgets(line, PATH_MAX, pipe_file) == NULL) {
break;
+ }
alpm_logaction(handle, "ALPM-SCRIPTLET", "%s", line);
EVENT(handle, &event);
}
diff --git a/src/common/util-common.c b/src/common/util-common.c
index 3316eaec..ab74e7c6 100644
--- a/src/common/util-common.c
+++ b/src/common/util-common.c
@@ -17,6 +17,7 @@
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
+#include <errno.h>
#include <stdlib.h>
#include <string.h>
@@ -102,6 +103,30 @@ int llstat(char *path, struct stat *buf)
return ret;
}
+/** Wrapper around fgets() which properly handles EINTR
+ * @param s string to read into
+ * @param size maximum length to read
+ * @param stream stream to read from
+ * @return value returned by fgets()
+ */
+char *safe_fgets(char *s, int size, FILE *stream)
+{
+ char *ret;
+ int errno_save = errno, ferror_save = ferror(stream);
+ while((ret = fgets(s, size, stream)) == NULL && !feof(stream)) {
+ if(errno == EINTR) {
+ /* clear any errors we set and try again */
+ errno = errno_save;
+ if(!ferror_save) {
+ clearerr(stream);
+ }
+ } else {
+ break;
+ }
+ }
+ return ret;
+}
+
#ifndef HAVE_STRNDUP
/* A quick and dirty implementation derived from glibc */
/** Determines the length of a fixed-size string.
diff --git a/src/common/util-common.h b/src/common/util-common.h
index 576702fa..ca8db5ab 100644
--- a/src/common/util-common.h
+++ b/src/common/util-common.h
@@ -20,6 +20,7 @@
#ifndef _PM_UTIL_COMMON_H
#define _PM_UTIL_COMMON_H
+#include <stdio.h>
#include <sys/stat.h> /* struct stat */
const char *mbasename(const char *path);
@@ -27,6 +28,8 @@ char *mdirname(const char *path);
int llstat(char *path, struct stat *buf);
+char *safe_fgets(char *s, int size, FILE *stream);
+
#ifndef HAVE_STRNDUP
char *strndup(const char *s, size_t n);
#endif
diff --git a/src/pacman/ini.c b/src/pacman/ini.c
index 2a3ef0ed..2eb32302 100644
--- a/src/pacman/ini.c
+++ b/src/pacman/ini.c
@@ -66,7 +66,7 @@ static int _parse_ini(const char *file, ini_parser_fn cb, void *data,
goto cleanup;
}
- while(fgets(line, PATH_MAX, fp)) {
+ while(safe_fgets(line, PATH_MAX, fp)) {
char *key, *value, *ptr;
size_t line_len;
diff --git a/src/pacman/util.c b/src/pacman/util.c
index 6a095fdb..2671e54c 100644
--- a/src/pacman/util.c
+++ b/src/pacman/util.c
@@ -1403,7 +1403,7 @@ int multiselect_question(char *array, int count)
flush_term_input(fileno(stdin));
- if(fgets(response, response_len, stdin)) {
+ if(safe_fgets(response, response_len, stdin)) {
const size_t response_incr = 64;
size_t len;
/* handle buffer not being large enough to read full line case */
@@ -1416,7 +1416,7 @@ int multiselect_question(char *array, int count)
lastchar = response + response_len - 1;
/* sentinel byte */
*lastchar = 1;
- if(fgets(response + response_len - response_incr - 1,
+ if(safe_fgets(response + response_len - response_incr - 1,
response_incr + 1, stdin) == 0) {
free(response);
return -1;
@@ -1467,7 +1467,7 @@ int select_question(int count)
flush_term_input(fileno(stdin));
- if(fgets(response, sizeof(response), stdin)) {
+ if(safe_fgets(response, sizeof(response), stdin)) {
size_t len = strtrim(response);
if(len > 0) {
int n;
@@ -1521,7 +1521,7 @@ static int question(short preset, const char *format, va_list args)
flush_term_input(fd_in);
- if(fgets(response, sizeof(response), stdin)) {
+ if(safe_fgets(response, sizeof(response), stdin)) {
size_t len = strtrim(response);
if(len == 0) {
return preset;