From 4b540cf913b8f528fadb9357530a34ea0dc09737 Mon Sep 17 00:00:00 2001 From: Victoria Dye Date: Thu, 4 Nov 2021 04:01:03 +0000 Subject: [PATCH] async_die_is_recursing: work around GCC v11.x issue on Fedora This fix corrects an issue found in the `dockerized(pedantic, fedora)` CI build, first appearing after the introduction of a new version of the Fedora docker image version. This image includes a version of `glibc` with the attribute `__attr_access_none` added to `pthread_setspecific` [1], the implementation of which only exists for GCC 11.X - the version included in the Fedora image. The attribute requires that the pointer provided in the second argument of `pthread_getspecific` must, if not NULL, be a pointer to a valid object. In the usage in `async_die_is_recursing`, `(void *)1` is not valid, causing the error. This fix imitates a workaround added in SELinux [2] by using the pointer to the static `async_die_counter` itself as the second argument to `pthread_setspecific`. This guaranteed non-NULL, valid pointer matches the intent of the current usage while not triggering the build error. [1] https://sourceware.org/git/?p=glibc.git;a=commitdiff;h=a1561c3bbe8 [2] https://lore.kernel.org/all/20211021140519.6593-1-cgzones@googlemail.com/ Co-authored-by: Johannes Schindelin Signed-off-by: Victoria Dye Acked-by: Jeff King Signed-off-by: Junio C Hamano --- run-command.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/run-command.c b/run-command.c index 87ddce02ef..a06c43b533 100644 --- a/run-command.c +++ b/run-command.c @@ -614,7 +614,7 @@ static NORETURN void die_async(const char *err, va_list params) static int async_die_is_recursing(void) { void *ret = pthread_getspecific(async_die_counter); - pthread_setspecific(async_die_counter, (void *)1); + pthread_setspecific(async_die_counter, &async_die_counter); /* set to any non-NULL valid pointer */ return ret != NULL; }