On Mon, Mar 25, 2024 at 9:50 AM kernel test robot <[email protected]> wrote:
>
>
> hi, Uros Bizjak,
>
> we reported an early crash issue for this commit last Oct.
> https://lore.kernel.org/all/[email protected]/
>
> as you mentioned at that time
> "It is KASAN that is not compatible with named address spaces [1]."
>
> now we noticed the commit is merged into mainline, and we observed a different
> issue related with kcsan_setup_watchpoint. below detail report FYI.
>
> [1] https://lore.kernel.org/lkml/CAHk-=wi6U-O1wdPOESuCE6QO2OaPu0hEzaig0uDOU4L5CREhug@mail.gmail.com/
>
Yes, it is the same issue, but with KCSAN.
> Hello,
>
> kernel test robot noticed "BUG:unable_to_handle_page_fault_for_address" on:
>
> commit: ca4256348660cb2162668ec3d13d1f921d05374a ("x86/percpu: Use C for percpu read/write accessors")
> https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
>
> [test failed on linus/master b3603fcb79b1036acae10602bffc4855a4b9af80]
> [test failed on linux-next/master 226d3c72fcde130a99d760895ebdd20e78e02cb5]
>
> in testcase: boot
>
> compiler: gcc-12
> test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
We already have the candidate fix for GCC [1], the fix will be in gcc-13.3+.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111736
Please find attached an emergency patch for mainline that disables
named address spaces when KCSAN is enabled. I'll post a formal patch
submission in a moment. The named AS will be re-enabled with KCSAN
with a patch via -tip tree.
Thanks,
Uros.
hi, Uros Bizjak,
On Mon, Mar 25, 2024 at 11:31:40AM +0100, Uros Bizjak wrote:
> On Mon, Mar 25, 2024 at 9:50 AM kernel test robot <[email protected]> wrote:
> >
> >
> > hi, Uros Bizjak,
> >
> > we reported an early crash issue for this commit last Oct.
> > https://lore.kernel.org/all/[email protected]/
> >
> > as you mentioned at that time
> > "It is KASAN that is not compatible with named address spaces [1]."
> >
> > now we noticed the commit is merged into mainline, and we observed a different
> > issue related with kcsan_setup_watchpoint. below detail report FYI.
> >
> > [1] https://lore.kernel.org/lkml/CAHk-=wi6U-O1wdPOESuCE6QO2OaPu0hEzaig0uDOU4L5CREhug@mail.gmail.com/
> >
>
> Yes, it is the same issue, but with KCSAN.
>
> > Hello,
> >
> > kernel test robot noticed "BUG:unable_to_handle_page_fault_for_address" on:
> >
> > commit: ca4256348660cb2162668ec3d13d1f921d05374a ("x86/percpu: Use C for percpu read/write accessors")
> > https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git master
> >
> > [test failed on linus/master b3603fcb79b1036acae10602bffc4855a4b9af80]
> > [test failed on linux-next/master 226d3c72fcde130a99d760895ebdd20e78e02cb5]
> >
> > in testcase: boot
> >
> > compiler: gcc-12
> > test machine: qemu-system-x86_64 -enable-kvm -cpu SandyBridge -smp 2 -m 16G
>
> We already have the candidate fix for GCC [1], the fix will be in gcc-13.3+.
>
> [1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=111736
>
> Please find attached an emergency patch for mainline that disables
> named address spaces when KCSAN is enabled. I'll post a formal patch
> submission in a moment. The named AS will be re-enabled with KCSAN
> with a patch via -tip tree.
thanks a lot for information! we will apply this patch.
>
> Thanks,
> Uros.
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 39886bab943a..4fff6ed46e90 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -2439,6 +2439,8 @@ config USE_X86_SEG_SUPPORT
> # with named address spaces - see GCC PR sanitizer/111736.
> #
> depends on !KASAN
> + # -fsanitize=thread (KCSAN) is also incompatible.
> + depends on !KCSAN
>
> config CC_HAS_SLS
> def_bool $(cc-option,-mharden-sls=all)