Re: [GIT PULL] tracing: More updates for 6.13

[Paul Moore]

On November 28, 2024 9:17:31 PM Yafang Shao <laoar.shao@xxxxxxxxx> wrote:
> On Fri, Nov 29, 2024 at 7:23 AM Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> > On Thu, 28 Nov 2024 15:51:20 -0500
> > Steven Rostedt <rostedt@xxxxxxxxxxx> wrote:
> >
> > > > I've pushed out my resolution, and hopefully rust people can actually
> > > > test it. I might just be full of it.
> > >
> > > Looks better than what I had. I'll kick my tests on it just as a sanity
> > > check.
> >
> > And my tests failed. But not for this change. The build failed. Config 
> > attached:
> >
> > CC      kernel/time/tick-broadcast.o
> > In file included from 
> > /work/build/trace/nobackup/linux-test.git/include/linux/string.h:390,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/bitmap.h:13,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/cpumask.h:12,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/smp.h:13,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/lockdep.h:14,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/spinlock.h:63,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/wait.h:9,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/wait_bit.h:8,
> >         from /work/build/trace/nobackup/linux-test.git/include/linux/fs.h:6,
> >         from /work/build/trace/nobackup/linux-test.git/kernel/auditsc.c:37:
> > In function ‘sized_strscpy’,
> > inlined from ‘__audit_ptrace’ at 
> > /work/build/trace/nobackup/linux-test.git/kernel/auditsc.c:2732:2:
> > /work/build/trace/nobackup/linux-test.git/include/linux/fortify-string.h:293:17: 
> > error: call to ‘__write_overflow’ declared with attribute error: detected 
> > write beyond size of object (1st parameter)
> > 293 |                 __write_overflow();
> > |                 ^~~~~~~~~~~~~~~~~~
> > CC      arch/x86/kernel/tracepoint.o
> > In function ‘sized_strscpy’,
> > inlined from ‘audit_signal_info_syscall’ at 
> > /work/build/trace/nobackup/linux-test.git/kernel/auditsc.c:2759:3:
> > /work/build/trace/nobackup/linux-test.git/include/linux/fortify-string.h:293:17: 
> > error: call to ‘__write_overflow’ declared with attribute error: detected 
> > write beyond size of object (1st parameter)
> > 293 |                 __write_overflow();
> > |                 ^~~~~~~~~~~~~~~~~~
> > AR      drivers/nvmem/built-in.a
> > make[4]: *** 
> > [/work/build/trace/nobackup/linux-test.git/scripts/Makefile.build:229: 
> > kernel/auditsc.o] Error 1
> >
> > I'm currently too busy eating turkey, so I'll let someone else figure this out.
>
> The issue appears to be a known GCC bug, though the root cause remains
> unclear at this time.
>
> A potential workaround has been proposed, which you can find here:
> https://lore.kernel.org/linux-hardening/202410171059.C2C395030@keescook/
>
> However, it seems that the patch has not yet been accepted into the mainline.

I didn't pull that into the audit tree because it isn't a real patch. 
Looking at it again on my phone before today's holiday stuff kicks off, I 
don't have a problem with the workaround, but i do need to see it as a 
proper patch with a commit description, sign off, etc. before I can merge it.

For anyone who is going to put together a patch, please make it clear that 
it is a compiler bug and provide the associated bug report links.

--
paul-moore.com