On Mon, Mar 25, 2024 at 9:50 AM kernel test robot <oliver.sang@xxxxxxxxx> wrote: > > > hi, Uros Bizjak, > > we reported an early crash issue for this commit last Oct. > https://lore.kernel.org/all/202310071301.a5113890-oliver.sang@xxxxxxxxx/ > > 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@xxxxxxxxxxxxxx/ > 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.
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)
