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From: "tom dot honermann at oracle dot com" <sourceware-bugzilla@sourceware.org> To: glibc-bugs@sources.redhat.com Subject: [Bug libc/4737] fork is not async-signal-safe Date: Tue, 11 Nov 2008 21:41:00 -0000 [thread overview] Message-ID: <20081111213956.21520.qmail@sourceware.org> (raw) In-Reply-To: <20070704013541.4737.nmiell@comcast.net> ------- Additional Comments From tom dot honermann at oracle dot com 2008-11-11 21:39 ------- (In reply to comment #7) > It is, as far as I can see, not a problem of the fork() implementation > allocating memory. I believe that it's: > > 1) a problem of glibc's malloc() implementation registering ptmalloc_lock_all() > for execution at fork (via thread_atfork()) while not making sure that this > function can actually be called from a signal handler without deadlocking. > Fork() just calls each registered function. It can not, in any way, know if > these functions will lock up the process - that is the responsibility of whoever > registers a the function for execution. This must be a bug in malloc/arena.c. > This is the bug you (Nicholas) hit. Absolutely correct. ptmalloc_lock_all, ptmalloc_unlock_all, and ptmalloc_unlock_all2 are not async-signal-safe as is required to be called within the context of a signal handler. > > 2) a problem of fork() calling _IO_list_lock() which might be locked by the main > execution flow. This must be a bug in nptl/sysdeps/unix/sysv/linux/fork.c. This > is the bug I hit. > > I think it looks like two separate bugs, which are triggered by similar > conditions. The fix might be identical; I don't know. These look like two separate bugs to me as well. I haven't hit the _IO_list_lock related one myself yet, but I suspect it is only a matter of time... -- http://sourceware.org/bugzilla/show_bug.cgi?id=4737 ------- You are receiving this mail because: ------- You are on the CC list for the bug, or are watching someone who is.
next prev parent reply other threads:[~2008-11-11 21:41 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2007-07-04 1:35 [Bug libc/4737] New: " nmiell at comcast dot net 2008-10-11 18:47 ` [Bug libc/4737] " morten+sources dot redhat dot com at afdelingp dot dk 2008-10-20 11:47 ` morten+sources dot redhat dot com at afdelingp dot dk 2008-10-21 5:13 ` nmiell at comcast dot net 2008-10-30 14:55 ` morten+sources dot redhat dot com at afdelingp dot dk 2008-11-05 9:00 ` tom dot honermann at oracle dot com 2008-11-05 9:57 ` tom dot honermann at oracle dot com 2008-11-06 23:10 ` nmiell at comcast dot net 2008-11-07 1:10 ` morten+sources dot redhat dot com at afdelingp dot dk 2008-11-11 21:35 ` tom dot honermann at oracle dot com 2008-11-11 21:41 ` tom dot honermann at oracle dot com [this message] 2008-11-11 22:04 ` tom dot honermann at oracle dot com 2008-11-18 22:30 ` tom dot honermann at oracle dot com 2008-11-18 23:45 ` rsa at us dot ibm dot com 2008-11-18 23:57 ` rsa at us dot ibm dot com 2008-11-19 1:39 ` tom dot honermann at oracle dot com 2008-11-19 16:23 ` rsa at us dot ibm dot com 2009-01-14 1:22 ` tom dot honermann at oracle dot com 2009-01-14 8:46 ` jakub at redhat dot com 2009-01-14 9:44 ` tom dot honermann at oracle dot com 2009-01-16 17:19 ` tom dot honermann at oracle dot com [not found] <bug-4737-131@http.sourceware.org/bugzilla/> 2011-10-13 17:53 ` llucax at gmail dot com 2011-10-13 17:54 ` llucax at gmail dot com 2011-10-13 17:56 ` llucax at gmail dot com 2011-10-14 14:06 ` bugdal at aerifal dot cx 2012-03-27 13:43 ` krebbel1 at de dot ibm.com 2012-04-11 7:58 ` aj at suse dot de 2014-02-16 19:42 ` jackie.rosen at hushmail dot com 2014-05-28 19:41 ` schwab at sourceware dot org 2014-08-25 2:25 ` naesten at gmail dot com 2015-05-07 15:27 ` gbenson at redhat dot com 2021-06-28 19:00 ` adhemerval.zanella at linaro dot org
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