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[PATCH] Don't close or flush stdio streams on abort
- From: Andreas Schwab <schwab at suse dot de>
- To: libc-alpha at sourceware dot org
- Date: Wed, 08 May 2013 11:31:05 +0200
- Subject: [PATCH] Don't close or flush stdio streams on abort
[BZ #15436]
* stdlib/abort.c (abort): Don't call fflush and __fcloseall.
---
NEWS | 4 ++++
stdlib/abort.c | 29 +++++------------------------
2 files changed, 9 insertions(+), 24 deletions(-)
diff --git a/NEWS b/NEWS
index 95a4e4f..e9bffbe 100644
--- a/NEWS
+++ b/NEWS
@@ -38,6 +38,10 @@ Version 2.18
* New <math.h> macro named issignaling to check for a signaling NaN (sNaN).
It is based on draft TS 18661 and currently enabled as a GNU extension.
+
+* The abort function no longer tries to flush or close any stdio streams.
+ Doing so would run into locking problems because abort is required to be
+ async-signal-safe, but fflush and fclose cannot be.
Version 2.17
diff --git a/stdlib/abort.c b/stdlib/abort.c
index 72b2d60..4b7df18 100644
--- a/stdlib/abort.c
+++ b/stdlib/abort.c
@@ -30,9 +30,6 @@
# define ABORT_INSTRUCTION
#endif
-#include <libio/libioP.h>
-#define fflush(s) _IO_flush_all_lockp (0)
-
/* Exported variable to locate abort message in core files etc. */
struct abort_msg_s *__abort_msg __attribute__ ((nocommon));
libc_hidden_def (__abort_msg)
@@ -66,16 +63,8 @@ abort (void)
__sigprocmask (SIG_UNBLOCK, &sigs, (sigset_t *) NULL);
}
- /* Flush all streams. We cannot close them now because the user
- might have registered a handler for SIGABRT. */
- if (stage == 1)
- {
- ++stage;
- fflush (NULL);
- }
-
/* Send signal which possibly calls a user handler. */
- if (stage == 2)
+ if (stage == 1)
{
/* This stage is special: we must allow repeated calls of
`abort' when a user defined handler for SIGABRT is installed.
@@ -93,7 +82,7 @@ abort (void)
}
/* There was a handler installed. Now remove it. */
- if (stage == 3)
+ if (stage == 2)
{
++stage;
memset (&act, '\0', sizeof (struct sigaction));
@@ -103,30 +92,22 @@ abort (void)
__sigaction (SIGABRT, &act, NULL);
}
- /* Now close the streams which also flushes the output the user
- defined handler might has produced. */
- if (stage == 4)
- {
- ++stage;
- __fcloseall ();
- }
-
/* Try again. */
- if (stage == 5)
+ if (stage == 3)
{
++stage;
raise (SIGABRT);
}
/* Now try to abort using the system specific command. */
- if (stage == 6)
+ if (stage == 4)
{
++stage;
ABORT_INSTRUCTION;
}
/* If we can't signal ourselves and the abort instruction failed, exit. */
- if (stage == 7)
+ if (stage == 5)
{
++stage;
_exit (127);
--
1.8.2.2
--
Andreas Schwab, SUSE Labs, schwab@suse.de
GPG Key fingerprint = 0196 BAD8 1CE9 1970 F4BE 1748 E4D4 88E3 0EEA B9D7
"And now for something completely different."