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Merged revisions 332321 via svnmerge from 

https://origsvn.digium.com/svn/asterisk/branches/10

................
  r332321 | twilson | 2011-08-17 13:09:49 -0500 (Wed, 17 Aug 2011) | 17 lines
  
  Merged revisions 332320 via svnmerge from 
  https://origsvn.digium.com/svn/asterisk/branches/1.8
  
  ........
    r332320 | twilson | 2011-08-17 12:35:27 -0500 (Wed, 17 Aug 2011) | 10 lines
    
    Don't read from a disarmed or invalid timerfd
    
    Numerous isues have been reported for deadlocks that are caused by
    a blocking read in res_timing_timerfd on a file descriptor that will
    never be written to. This patch adds some checks to make sure that
    the timerfd is both valid and armed before calling read().
    
    Should fix: ASTERISK-18142, ASTERISK-18166, ASTERISK-18197, AST-486,
    AST-495, AST-507 and possibly others.

    Review: https://reviewboard.asterisk.org/r/1361/
  ........
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git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@332337 65c4cc65-6c06-0410-ace0-fbb531ad65f3
This commit is contained in:
Terry Wilson 2011-08-17 18:31:39 +00:00
parent 265102faf8
commit c38cb95863
1 changed files with 27 additions and 0 deletions
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27
res/res_timing_timerfd.c
View File

@ -162,8 +162,32 @@ static void timerfd_timer_ack(int handle, unsigned int quantity)
{
uint64_t expirations;
int read_result = 0;
struct timerfd_timer *our_timer, find_helper = {
.handle = handle,
};
if (!(our_timer = ao2_find(timerfd_timers, &find_helper, OBJ_POINTER))) {
ast_log(LOG_ERROR, "Couldn't find a timer with handle %d\n", handle);
return;
}
ao2_lock(our_timer);
do {
struct itimerspec timer_status;
if (timerfd_gettime(handle, &timer_status)) {
ast_log(LOG_ERROR, "Call to timerfd_gettime() error: %s\n", strerror(errno));
expirations = 0;
break;
}
if (timer_status.it_value.tv_sec == 0 && timer_status.it_value.tv_nsec == 0) {
ast_debug(1, "Avoiding read on disarmed timerfd %d\n", handle);
expirations = 0;
break;
}
read_result = read(handle, &expirations, sizeof(expirations));
if (read_result == -1) {
if (errno == EINTR || errno == EAGAIN) {
@ -175,6 +199,9 @@ static void timerfd_timer_ack(int handle, unsigned int quantity)
}
} while (read_result != sizeof(expirations));
ao2_unlock(our_timer);
ao2_ref(our_timer, -1);
if (expirations != quantity) {
ast_debug(2, "Expected to acknowledge %u ticks but got %llu instead\n", quantity, (unsigned long long) expirations);
}