From: "Victoria Dye via GitGitGadget" <gitgitgadget@gmail.com>
To: git@vger.kernel.org
Cc: gitster@pobox.com, philipoakley@iee.email,
eschwartz@archlinux.org, Carlo Arenas <carenas@gmail.com>,
Jeff King <peff@peff.net>, Victoria Dye <vdye@github.com>,
Victoria Dye <vdye@github.com>
Subject: [PATCH v2] async_die_is_recursing: work around GCC v11.x issue on Fedora
Date: Thu, 04 Nov 2021 04:01:03 +0000 [thread overview]
Message-ID: <pull.1072.v2.git.1635998463474.gitgitgadget@gmail.com> (raw)
In-Reply-To: <pull.1072.git.1635990465854.gitgitgadget@gmail.com>
From: Victoria Dye <vdye@github.com>
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 <johannes.schindelin@gmx.de>
Signed-off-by: Victoria Dye <vdye@github.com>
---
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@tvgsbejvaqbjf.bet/
[2]
https://lore.kernel.org/git/43fe6d5c-bdb2-585c-c601-1da7a1b3ff8b@archlinux.org/
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@github.com>
## 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@googlemail.com/
@@ 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
next prev parent reply other threads:[~2021-11-04 4:01 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-04 1:47 [PATCH] async_die_is_recursing: fix use of pthread_getspecific for Fedora Victoria Dye via GitGitGadget
2021-11-04 2:23 ` Carlo Arenas
2021-11-04 2:37 ` Jeff King
2021-11-04 3:20 ` Carlo Arenas
2021-11-04 5:56 ` Jeff King
2021-11-04 4:01 ` Victoria Dye via GitGitGadget [this message]
2021-11-04 5:58 ` [PATCH v2] async_die_is_recursing: work around GCC v11.x issue on Fedora Jeff King
2021-11-04 6:35 ` Junio C Hamano
2021-11-04 9:42 ` Ævar Arnfjörð Bjarmason
2021-11-04 13:08 ` Derrick Stolee
2021-11-04 17:46 ` Junio C Hamano
2021-11-05 21:45 ` Junio C Hamano
2021-11-04 8:43 ` Johannes Schindelin
2021-11-04 9:46 ` Carlo Arenas
2021-11-04 16:33 ` Johannes Schindelin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=pull.1072.v2.git.1635998463474.gitgitgadget@gmail.com \
--to=gitgitgadget@gmail.com \
--cc=carenas@gmail.com \
--cc=eschwartz@archlinux.org \
--cc=git@vger.kernel.org \
--cc=gitster@pobox.com \
--cc=peff@peff.net \
--cc=philipoakley@iee.email \
--cc=vdye@github.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).