From: Victoria Dye <vdye@xxxxxxxxxx> 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@xxxxxxxxxxxxxx/ Co-authored-by: Johannes Schindelin <johannes.schindelin@xxxxxx> Signed-off-by: Victoria Dye <vdye@xxxxxxxxxx> --- async_die_is_recursing: fix use of pthread_getspecific for Fedora Following up on Johannes' report earlier [1], this patch fixes a compiler error in the Fedora CI build (the same issue was identified in a local developer build about a week ago [2]). This fix changes the second argument in the call to pthread_setspecific from '(void *)1' to a valid pointer, thus preventing the error in the use of __attr_access_none. Changes since V1 ================ * Change &ret to &async_die_counter ("dummy" argument to pthread_setspecific) so that it's using a global (rather than local) variable * Fix typo in commit message (pthread_getspecific -> pthread_setspecific) [1] https://lore.kernel.org/git/nycvar.QRO.7.76.6.2111040007170.56@xxxxxxxxxxxxxxxxx/ [2] https://lore.kernel.org/git/43fe6d5c-bdb2-585c-c601-1da7a1b3ff8b@xxxxxxxxxxxxx/ Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-1072%2Fvdye%2Ffix-fedora-build-v2 Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-1072/vdye/fix-fedora-build-v2 Pull-Request: https://github.com/gitgitgadget/git/pull/1072 Range-diff vs v1: 1: efe0b398f54 ! 1: 7f10e09269a async_die_is_recursing: fix use of pthread_getspecific for Fedora @@ Metadata Author: Victoria Dye <vdye@xxxxxxxxxx> ## Commit message ## - async_die_is_recursing: fix use of pthread_getspecific for Fedora + async_die_is_recursing: work around GCC v11.x issue on Fedora - Correct an issue encountered in the `dockerized(pedantic, fedora)` CI build, - first appearing after the release of v36 as the latest stable version of the - Fedora docker image. This image includes a version of `glibc` with the - attribute `__attr_access_none` added to `pthread_getspecific` [1], the + 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 - Fedora. 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, - resulting in the error. + 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. - The fix imitates a workaround added in SELinux [2] by using the pointer to - `ret` as the second argument to `pthread_getspecific`. This guaranteed - non-NULL, valid pointer adheres to the current intended usage of - `pthread_getspecific` while not triggering the build 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@xxxxxxxxxxxxxx/ @@ run-command.c: static NORETURN void die_async(const char *err, va_list params) { void *ret = pthread_getspecific(async_die_counter); - pthread_setspecific(async_die_counter, (void *)1); -+ pthread_setspecific(async_die_counter, &ret); /* set to any non-NULL valid pointer */ ++ pthread_setspecific(async_die_counter, &async_die_counter); /* set to any non-NULL valid pointer */ return ret != NULL; } run-command.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/run-command.c b/run-command.c index 7ef5cc712a9..f40df01c772 100644 --- a/run-command.c +++ b/run-command.c @@ -1099,7 +1099,7 @@ 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; } base-commit: 876b1423317071f43c99666f3fc3db3642dfbe14 -- gitgitgadget
