From: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
To: Florian Weimer <fweimer@redhat.com>,
Adhemerval Zanella via Libc-alpha <libc-alpha@sourceware.org>
Cc: Carlos O'Donell <carlos@redhat.com>
Subject: Re: [PATCH 1/2] setjmp: Use BSD sematic as default for setjmp
Date: Tue, 1 Aug 2023 10:51:40 -0300 [thread overview]
Message-ID: <40947004-fcac-d50c-feea-3a6512a10d69@linaro.org> (raw)
In-Reply-To: <871qgn5fds.fsf@oldenburg.str.redhat.com>
On 01/08/23 05:35, Florian Weimer wrote:
> * Adhemerval Zanella via Libc-alpha:
>
>> POSIX relaxed the relation of setjmp/longjmp and the signal mask
>> save/restore, meaning that setjmp does not require to be routed to
>> _setjmp to be standard compliant.
>>
>> This is done to avoid breakage of SIGABRT handlers, since to fully
>> make abort AS-safe, it is required to remove the recurisve lock
>> used to unblock SIGABRT prior raised the signal.
>>
>> Also, it allows caller to actually use setjmp, since from
>> 7011c2622fe3e10a29dbe74f06aaebd07710127d the symbol is unconditionally
>> routed to _setjmp.
>
> Doesn't this have non-trivial performance impact?
Yes, it is two extra sigprocmask to get/set the signal mask. This is not
*strictly* required, but the SIGABRT on abort generates racy conditions on
process creation and. This patch can be dropped, but it would mean that
to get expected semantic for abort handlers will need to use sigsetjmp (..., 1)
instead of setjmp.
next prev parent reply other threads:[~2023-08-01 13:51 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-31 17:18 [PATCH 0/2] Make abort AS-safe Adhemerval Zanella
2023-07-31 17:18 ` [PATCH 1/2] setjmp: Use BSD sematic as default for setjmp Adhemerval Zanella
2023-08-01 8:35 ` Florian Weimer
2023-08-01 13:51 ` Adhemerval Zanella Netto [this message]
2023-08-02 7:59 ` Florian Weimer
2023-08-02 12:32 ` Adhemerval Zanella Netto
2023-08-02 12:42 ` Florian Weimer
2023-08-02 12:48 ` Adhemerval Zanella Netto
2023-08-02 13:17 ` Florian Weimer
2023-08-02 13:29 ` Adhemerval Zanella Netto
2023-08-02 14:43 ` Florian Weimer
2023-08-02 14:56 ` Adhemerval Zanella Netto
2023-07-31 17:19 ` [PATCH 2/2] stdlib: Make abort AS-safe (BZ 26275) Adhemerval Zanella
2023-08-01 8:10 ` Florian Weimer
2023-08-01 13:52 ` Adhemerval Zanella Netto
2023-08-01 8:26 ` Florian Weimer
2023-08-01 13:57 ` Adhemerval Zanella Netto
2023-08-01 13:44 ` Cristian Rodríguez
2023-08-02 7:57 ` Florian Weimer
2023-08-02 13:08 ` Adhemerval Zanella Netto
2023-08-02 14:44 ` Florian Weimer
2023-08-02 14:48 ` Adhemerval Zanella Netto
2023-08-02 12:38 ` Florian Weimer
2023-08-02 13:08 ` Adhemerval Zanella Netto
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=40947004-fcac-d50c-feea-3a6512a10d69@linaro.org \
--to=adhemerval.zanella@linaro.org \
--cc=carlos@redhat.com \
--cc=fweimer@redhat.com \
--cc=libc-alpha@sourceware.org \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).