diff options
| author | Davide Cavalca <davide@cavalca.name> | 2025-07-31 17:32:58 +0200 |
|---|---|---|
| committer | Mark Wielaard <mark@klomp.org> | 2025-08-01 13:30:28 +0200 |
| commit | fd18059c0fcf5568db3688da47403b663cf91c5e (patch) | |
| tree | db670d5b9fd73f666310956ad2c22a1b7f51db1f | |
| parent | bc13db73937730401d592b33092db6df806d193e (diff) | |
stdlib: resolve a double lock init issue after fork [BZ #32994]
The __abort_fork_reset_child (introduced in
d40ac01cbbc66e6d9dbd8e3485605c63b2178251) call resets the lock after the
fork. This causes a DRD regression in valgrind
(https://bugs.kde.org/show_bug.cgi?id=503668), as it's effectively a
double initialization, despite it being actually ok in this case. As
suggested in https://sourceware.org/bugzilla/show_bug.cgi?id=32994#c2
we replace it here with a memcpy of another initialized lock instead,
which makes valgrind happy.
Reviewed-by: Florian Weimer <fweimer@redhat.com>
(cherry picked from commit d9a348d0927c7a1aec5caf3df3fcd36956b3eb23)
| -rw-r--r-- | NEWS | 2 | ||||
| -rw-r--r-- | stdlib/abort.c | 6 |
2 files changed, 6 insertions, 2 deletions
@@ -9,7 +9,7 @@ Version 2.42.1 The following bugs were resolved with this release: - [insert bugs here] + [32994] stdlib: resolve a double lock init issue after fork Version 2.42 diff --git a/stdlib/abort.c b/stdlib/abort.c index caa9e6dc04..904244a2fb 100644 --- a/stdlib/abort.c +++ b/stdlib/abort.c @@ -19,6 +19,7 @@ #include <internal-signals.h> #include <libc-lock.h> #include <pthreadP.h> +#include <string.h> #include <unistd.h> /* Try to get a machine dependent instruction which will make the @@ -42,7 +43,10 @@ __libc_rwlock_define_initialized (static, lock); void __abort_fork_reset_child (void) { - __libc_rwlock_init (lock); + /* Reinitialize lock without calling pthread_rwlock_init, to + avoid a valgrind DRD false positive. */ + __libc_rwlock_define_initialized (, reset_lock); + memcpy (&lock, &reset_lock, sizeof (lock)); } void |