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| author | Davide Cavalca <davide@cavalca.name> | 2025-07-31 17:32:58 +0200 |
|---|---|---|
| committer | Florian Weimer <fweimer@redhat.com> | 2025-07-31 19:11:08 +0200 |
| commit | d9a348d0927c7a1aec5caf3df3fcd36956b3eb23 (patch) | |
| tree | eeeff5d9c349faceda6f1e4d1441230582b0c00f | |
| parent | 258126bc0b77d7f9ae7d0b2737ec66e186c1e0ef (diff) | |
| download | glibc-d9a348d0927c7a1aec5caf3df3fcd36956b3eb23.zip glibc-d9a348d0927c7a1aec5caf3df3fcd36956b3eb23.tar.gz glibc-d9a348d0927c7a1aec5caf3df3fcd36956b3eb23.tar.bz2 | |
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>
| -rw-r--r-- | stdlib/abort.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/stdlib/abort.c b/stdlib/abort.c index caa9e6d..904244a 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 |