Messages in this thread | | | Date | Thu, 17 Nov 2022 14:58:37 +0100 | From | Marco Elver <> | Subject | Re: WARNING: CPU: 0 PID: 0 at arch/x86/include/asm/kfence.h:46 kfence_protect |
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On Thu, Nov 17, 2022 at 05:01PM +0530, Naresh Kamboju wrote: > Kunit test cases failed and found warnings while booting Linux next > version 6.1.0-rc5-next-20221117 on qemu-x86_64 [1]. > > It was working on Linux next-20221116 tag. > > [ 0.663761] WARNING: CPU: 0 PID: 0 at > arch/x86/include/asm/kfence.h:46 kfence_protect+0x7b/0x120 > [ 0.664033] WARNING: CPU: 0 PID: 0 at mm/kfence/core.c:234 > kfence_protect+0x7d/0x120 > [ 0.664465] kfence: kfence_init failed > > Reported-by: Linux Kernel Functional Testing <lkft@linaro.org> [...] > [ 0.663758] ------------[ cut here ]------------ > [ 0.663761] WARNING: CPU: 0 PID: 0 at > arch/x86/include/asm/kfence.h:46 kfence_protect+0x7b/0x120 [...] > [ 0.664465] kfence: kfence_init failed > > metadata: > git_ref: master > git_repo: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next > git_sha: af37ad1e01c72483c4ee8453d9d9bac95d35f023 > git_describe: next-20221117 > kernel_version: 6.1.0-rc5 > kernel-config: https://builds.tuxbuild.com/2Hfb6n1z0frt4iBlIvqUzjMHiLm/config > build-url: https://gitlab.com/Linaro/lkft/mirrors/next/linux-next/-/pipelines/697483979 > artifact-location: https://builds.tuxbuild.com/2Hfb6n1z0frt4iBlIvqUzjMHiLm > toolchain: gcc-11
I bisected this to:
commit 127960a05548ea699a95791669e8112552eb2452 Author: Peter Zijlstra <peterz@infradead.org> Date: Thu Nov 10 13:33:57 2022 +0100
x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias()
There is a cludge in change_page_attr_set_clr() that inhibits propagating NX changes to the aliases (directmap and highmap) -- this is a cludge twofold:
- it also inhibits the primary checks in __change_page_attr(); - it hard depends on single bit changes.
The introduction of set_memory_rox() triggered this last issue for clearing both _PAGE_RW and _PAGE_NX.
Explicitly ignore _PAGE_NX in cpa_process_alias() instead.
Fixes: b38994948567 ("x86/mm: Implement native set_memory_rox()") Reported-by: kernel test robot <oliver.sang@intel.com> Debugged-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20221110125544.594991716%40infradead.org
A simple revert of this commit fixes the issue.
Since all this seems to be about set_memory_rox(), and this is a fix commit, the fix itself missed something?
Thanks, -- Marco
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