The patch titled
Subject: kmsan: core: kmsan_in_runtime() should return true in NMI context
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
kmsan-core-kmsan_in_runtime-should-return-true-in-nmi-context.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kmsan-core-kmsan_in_runtime-should-return-true-in-nmi-context.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Alexander Potapenko <glider@xxxxxxxxxx>
Subject: kmsan: core: kmsan_in_runtime() should return true in NMI context
Date: Wed, 2 Nov 2022 12:06:07 +0100
Without that, every call to __msan_poison_alloca() in NMI may end up
allocating memory, which is NMI-unsafe.
Link: https://lkml.kernel.org/r/20221102110611.1085175-1-glider@xxxxxxxxxx
Link: https://lore.kernel.org/lkml/20221025221755.3810809-1-glider@xxxxxxxxxx/
Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx>
Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Cc: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kmsan/kmsan.h | 2 ++
1 file changed, 2 insertions(+)
--- a/mm/kmsan/kmsan.h~kmsan-core-kmsan_in_runtime-should-return-true-in-nmi-context
+++ a/mm/kmsan/kmsan.h
@@ -124,6 +124,8 @@ static __always_inline bool kmsan_in_run
{
if ((hardirq_count() >> HARDIRQ_SHIFT) > 1)
return true;
+ if (in_nmi())
+ return true;
return kmsan_get_context()->kmsan_in_runtime;
}
_
Patches currently in -mm which might be from glider@xxxxxxxxxx are
kmsan-core-kmsan_in_runtime-should-return-true-in-nmi-context.patch
x86-uaccess-instrument-copy_from_user_nmi.patch
kconfigdebug-ensure-early-check-for-kmsan-in-config_kmsan_warn.patch
kmsan-make-sure-preempt_rt-is-off.patch
x86-traps-avoid-kmsan-bugs-originating-from-handle_bug.patch
