Messages in this thread | | | Date | Wed, 9 Sep 2020 00:25:24 +0200 | From | Pavel Machek <> | Subject | Re: [PATCH] x86: work around clang IAS bug referencing __force_order |
| |
On Sat 2020-08-22 11:51:56, Sedat Dilek wrote: > On Sat, Aug 22, 2020 at 11:23 AM Sedat Dilek <sedat.dilek@gmail.com> wrote: > > > > On Sat, Aug 22, 2020 at 10:42 AM Segher Boessenkool > > <segher@kernel.crashing.org> wrote: > > > > > > Hi Arvind, > > > > > > On Fri, Aug 21, 2020 at 11:55:52PM -0400, Arvind Sankar wrote: > > > > Cc Segher. > > > > > > > > Segher, we were looking at gcc PR82602, where IRA could reorder volatile > > > > asm's (reported on ARM). The fix was backported to gcc-6. > > > > > > I know ;-) > > > > > > > Do you know if > > > > there is any reason the problem couldn't occur on x86 on older gcc > > > > without the fix? > > > > > > No, I see no particular reason, at least GCC 5 seems vulnerable. (The > > > GCC 5 release branch was closed at the time this bug report was made, > > > already). There is no reason I see why it would work on x86 but fail > > > elsewhere, either. > > > > > > > [1] says: > > > > Current Minimal Requirements > > ... > > ====================== =============== ======================================== > > Program Minimal version Command to check the version > > ====================== =============== ======================================== > > GNU C 4.9 gcc --version > > > > - Sedat - > > > > [1] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/changes.rst#n32 > > [ CC Miguel Ojeda (Compiler Attributes maintainer) ] > > There exist gcc-4.8 and gcc-4.9 for Debian/jessie where EOL was June > 30, 2020 (see [1] and [2]). > > In the latest available version "4.9.2-10+deb8u1" I see no PR82602 was > backported (see [3] and [4]). > > I am asking myself who is using such ancient compilers? > Recently, I threw away GCC-8 from my Debian system.
I do have 4.9.2 on some systems. They work well, and are likely to compile significantly faster than newer ones.
Please don't break them.
Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
| |