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Always do locking when iterating over list of streams (bug 15142)

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_IO_list_all should only be traversed while locking list_all_lock.
This commit is contained in:
Andreas Schwab
2017-08-21 16:07:29 +02:00
parent 91e7cf982d
commit 19f82f3586
2 changed files with 26 additions and 42 deletions
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8
ChangeLog
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@@ -1,3 +1,11 @@
2017-10-05 Andreas Schwab <schwab@suse.de>
[BZ #15142]
* libio/genops.c (_IO_list_all_stamp): Delete. All uses removed.
(_IO_flush_all_lockp): Always lock list_all_lock.
(_IO_flush_all_linebuffered): Likewise.
(_IO_unbuffer_all): Likewise.
2017-10-05 Florian Weimer <fweimer@redhat.com> 2017-10-05 Florian Weimer <fweimer@redhat.com>
[BZ #15436] [BZ #15436]

60
libio/genops.c
View File

@@ -36,10 +36,6 @@
static _IO_lock_t list_all_lock = _IO_lock_initializer; static _IO_lock_t list_all_lock = _IO_lock_initializer;
#endif #endif
/* Used to signal modifications to the list of FILE decriptors. */
static int _IO_list_all_stamp;
static _IO_FILE *run_fp; static _IO_FILE *run_fp;
#ifdef _IO_MTSAFE_IO #ifdef _IO_MTSAFE_IO
@@ -67,16 +63,12 @@ _IO_un_link (struct _IO_FILE_plus *fp)
if (_IO_list_all == NULL) if (_IO_list_all == NULL)
; ;
else if (fp == _IO_list_all) else if (fp == _IO_list_all)
{ _IO_list_all = (struct _IO_FILE_plus *) _IO_list_all->file._chain;
_IO_list_all = (struct _IO_FILE_plus *) _IO_list_all->file._chain;
++_IO_list_all_stamp;
}
else else
for (f = &_IO_list_all->file._chain; *f; f = &(*f)->_chain) for (f = &_IO_list_all->file._chain; *f; f = &(*f)->_chain)
if (*f == (_IO_FILE *) fp) if (*f == (_IO_FILE *) fp)
{ {
*f = fp->file._chain; *f = fp->file._chain;
++_IO_list_all_stamp;
break; break;
} }
fp->file._flags &= ~_IO_LINKED; fp->file._flags &= ~_IO_LINKED;
@@ -104,7 +96,6 @@ _IO_link_in (struct _IO_FILE_plus *fp)
#endif #endif
fp->file._chain = (_IO_FILE *) _IO_list_all; fp->file._chain = (_IO_FILE *) _IO_list_all;
_IO_list_all = fp; _IO_list_all = fp;
++_IO_list_all_stamp;
#ifdef _IO_MTSAFE_IO #ifdef _IO_MTSAFE_IO
_IO_funlockfile ((_IO_FILE *) fp); _IO_funlockfile ((_IO_FILE *) fp);
run_fp = NULL; run_fp = NULL;
@@ -758,17 +749,13 @@ _IO_flush_all_lockp (int do_lock)
{ {
int result = 0; int result = 0;
struct _IO_FILE *fp; struct _IO_FILE *fp;
int last_stamp;
#ifdef _IO_MTSAFE_IO #ifdef _IO_MTSAFE_IO
__libc_cleanup_region_start (do_lock, flush_cleanup, NULL); _IO_cleanup_region_start_noarg (flush_cleanup);
if (do_lock) _IO_lock_lock (list_all_lock);
_IO_lock_lock (list_all_lock);
#endif #endif
last_stamp = _IO_list_all_stamp; for (fp = (_IO_FILE *) _IO_list_all; fp != NULL; fp = fp->_chain)
fp = (_IO_FILE *) _IO_list_all;
while (fp != NULL)
{ {
run_fp = fp; run_fp = fp;
if (do_lock) if (do_lock)
@@ -785,21 +772,11 @@ _IO_flush_all_lockp (int do_lock)
if (do_lock) if (do_lock)
_IO_funlockfile (fp); _IO_funlockfile (fp);
run_fp = NULL; run_fp = NULL;
if (last_stamp != _IO_list_all_stamp)
{
/* Something was added to the list. Start all over again. */
fp = (_IO_FILE *) _IO_list_all;
last_stamp = _IO_list_all_stamp;
}
else
fp = fp->_chain;
} }
#ifdef _IO_MTSAFE_IO #ifdef _IO_MTSAFE_IO
if (do_lock) _IO_lock_unlock (list_all_lock);
_IO_lock_unlock (list_all_lock); _IO_cleanup_region_end (0);
__libc_cleanup_region_end (0);
#endif #endif
return result; return result;
@@ -818,16 +795,13 @@ void
_IO_flush_all_linebuffered (void) _IO_flush_all_linebuffered (void)
{ {
struct _IO_FILE *fp; struct _IO_FILE *fp;
int last_stamp;
#ifdef _IO_MTSAFE_IO #ifdef _IO_MTSAFE_IO
_IO_cleanup_region_start_noarg (flush_cleanup); _IO_cleanup_region_start_noarg (flush_cleanup);
_IO_lock_lock (list_all_lock); _IO_lock_lock (list_all_lock);
#endif #endif
last_stamp = _IO_list_all_stamp; for (fp = (_IO_FILE *) _IO_list_all; fp != NULL; fp = fp->_chain)
fp = (_IO_FILE *) _IO_list_all;
while (fp != NULL)
{ {
run_fp = fp; run_fp = fp;
_IO_flockfile (fp); _IO_flockfile (fp);
@@ -837,15 +811,6 @@ _IO_flush_all_linebuffered (void)
_IO_funlockfile (fp); _IO_funlockfile (fp);
run_fp = NULL; run_fp = NULL;
if (last_stamp != _IO_list_all_stamp)
{
/* Something was added to the list. Start all over again. */
fp = (_IO_FILE *) _IO_list_all;
last_stamp = _IO_list_all_stamp;
}
else
fp = fp->_chain;
} }
#ifdef _IO_MTSAFE_IO #ifdef _IO_MTSAFE_IO
@@ -879,6 +844,12 @@ static void
_IO_unbuffer_all (void) _IO_unbuffer_all (void)
{ {
struct _IO_FILE *fp; struct _IO_FILE *fp;
#ifdef _IO_MTSAFE_IO
_IO_cleanup_region_start_noarg (flush_cleanup);
_IO_lock_lock (list_all_lock);
#endif
for (fp = (_IO_FILE *) _IO_list_all; fp; fp = fp->_chain) for (fp = (_IO_FILE *) _IO_list_all; fp; fp = fp->_chain)
{ {
if (! (fp->_flags & _IO_UNBUFFERED) if (! (fp->_flags & _IO_UNBUFFERED)
@@ -921,6 +892,11 @@ _IO_unbuffer_all (void)
used. */ used. */
fp->_mode = -1; fp->_mode = -1;
} }
#ifdef _IO_MTSAFE_IO
_IO_lock_unlock (list_all_lock);
_IO_cleanup_region_end (0);
#endif
} }