Previously, the callback registered by pthread_atfork() is called before _my_tls.fixup_after_fork(). This causes misbehaviour if the callback uses tls related functions. Due to this problem, subprocess of cmake (> 3.29.x) sometimes fails after the commit 7ed9adb356df. The commit 7ed9adb356df triggers this issue, but it is not the issue of that patch. This patch moves the pthread::atforkchild() at the end of the fork::child().
Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257800.html Addresses: https://github.com/msys2/msys2-runtime/issues/272 Fixes: f02b22dcee17 ("* fork.cc (frok::child): Change order of cleanup prior to return.") Reported-by: Christoph Reiter <reiter.christ...@gmail.com> Reviewed-by: Jeremy Drake <cyg...@jdrake.com> Signed-off-by: Takashi Yano <takashi.y...@nifty.ne.jp> --- winsup/cygwin/fork.cc | 2 +- winsup/cygwin/release/3.6.1 | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/winsup/cygwin/fork.cc b/winsup/cygwin/fork.cc index 783971b76..f88acdbbf 100644 --- a/winsup/cygwin/fork.cc +++ b/winsup/cygwin/fork.cc @@ -187,7 +187,6 @@ frok::child (volatile char * volatile here) ForceCloseHandle1 (fork_info->forker_finished, forker_finished); - pthread::atforkchild (); cygbench ("fork-child"); ld_preload (); fixup_hooks_after_fork (); @@ -199,6 +198,7 @@ frok::child (volatile char * volatile here) CloseHandle (hParent); hParent = NULL; cygwin_finished_initializing = true; + pthread::atforkchild (); return 0; } diff --git a/winsup/cygwin/release/3.6.1 b/winsup/cygwin/release/3.6.1 index 07a29ecce..5a15642b8 100644 --- a/winsup/cygwin/release/3.6.1 +++ b/winsup/cygwin/release/3.6.1 @@ -31,3 +31,7 @@ Fixes: - Return EMFILE when opening /dev/ptmx too many times. Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257786.html + +- Move pthread::atforkchild() at the end of fork::child(). + Addresses: https://cygwin.com/pipermail/cygwin/2025-March/257800.html + Addresses: https://github.com/msys2/msys2-runtime/issues/272 -- 2.45.1
