From: Florian Weimer <fweimer@redhat.com>
To: James Y Knight <jyknight@google.com>
Cc: musl@lists.openwall.com
Subject: Re: [musl] add noexcept to all functions please
Date: Sun, 07 Nov 2021 19:20:21 +0100 [thread overview]
Message-ID: <87lf1z6d5m.fsf@oldenburg.str.redhat.com> (raw)
In-Reply-To: <CAA2zVHqHTh9OZfxPRo0XAL0npnDrMbebaYasZfMsuTArrN40eQ@mail.gmail.com> (James Y. Knight's message of "Sun, 7 Nov 2021 12:37:09 -0500")
* James Y. Knight:
> Glibc defines macros for this purpose, which expand into "throw()" in
> C++ and "__attribute__((__nothrow__))" in GCC-C. The latter is only
> useful in conjunction with an extremely-rarely-used feature, C code
> built with -fexceptions enabled, and is thus probably ignorable.
We build our distributions with -fexceptions
-fasynchronous-unwind-tables. These features have real uses out there
(although -fasynchronous-unwind-tables is probably more important for
performance analysis and diagnostics). With glibc, -fexceptions is
desirable to avoid unprotected function pointers on the stack in
conjunction with POSIX cancellation handlers (which can be relevant even
if unwinding does not happen).
I believe the musl cancellation implementation does not use DWARF
unwinding. I do not know if it cancellation handlers have the same
hardening gap as glibc's with setjmp-based unwinding.
Thanks,
Florian
next prev parent reply other threads:[~2021-11-07 18:20 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-11-06 17:15 sotrdg sotrdg
2021-11-06 18:28 ` Jon Chesterfield
2021-11-06 18:39 ` Joakim Sindholt
2021-11-07 17:37 ` James Y Knight
2021-11-07 18:20 ` Florian Weimer [this message]
2021-11-07 19:56 ` Markus Wichmann
2021-11-08 8:30 ` Florian Weimer
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