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Merge branch 'ti/glibc-stdio-mutex-from-signal-handler' into maint

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Allocation related functions and stdio are unsafe things to call
inside a signal handler, and indeed killing the pager can cause
glibc to deadlock waiting on allocation mutex as our signal handler
tries to free() some data structures in wait_for_pager().  Reduce
these unsafe calls.

* ti/glibc-stdio-mutex-from-signal-handler:
  pager: don't use unsafe functions in signal handlers
This commit is contained in:
Junio C Hamano
2015-10-16 14:32:41 -07:00
parent f4892a3c28 507d7804c0
commit 267ebf6c84
3 changed files with 34 additions and 14 deletions
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22
pager.c
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@ -14,19 +14,29 @@
static const char *pager_argv[] = { NULL, NULL };
static struct child_process pager_process = CHILD_PROCESS_INIT;
static void wait_for_pager(void)
static void wait_for_pager(int in_signal)
{
fflush(stdout);
fflush(stderr);
if (!in_signal) {
fflush(stdout);
fflush(stderr);
}
/* signal EOF to pager */
close(1);
close(2);
finish_command(&pager_process);
if (in_signal)
finish_command_in_signal(&pager_process);
else
finish_command(&pager_process);
}
static void wait_for_pager_atexit(void)
{
wait_for_pager(0);
}
static void wait_for_pager_signal(int signo)
{
wait_for_pager();
wait_for_pager(1);
sigchain_pop(signo);
raise(signo);
}
@ -90,7 +100,7 @@ void setup_pager(void)
/* this makes sure that the parent terminates after the pager */
sigchain_push_common(wait_for_pager_signal);
atexit(wait_for_pager);
atexit(wait_for_pager_atexit);
}
int pager_in_use(void)