+ kconfigdebug-disable-config_frame_warn-for-kmsan-by-default.patch added to mm-hotfixes-unstable branch

+ kconfigdebug-disable-config_frame_warn-for-kmsan-by-default.patch added to mm-hotfixes-unstable branch

[Andrew Morton]

The patch titled
     Subject: Kconfig.debug: disable CONFIG_FRAME_WARN for KMSAN by default
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     kconfigdebug-disable-config_frame_warn-for-kmsan-by-default.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kconfigdebug-disable-config_frame_warn-for-kmsan-by-default.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Alexander Potapenko <glider@google.com>
Subject: Kconfig.debug: disable CONFIG_FRAME_WARN for KMSAN by default
Date: Mon, 24 Oct 2022 23:21:42 +0200

KMSAN adds a lot of instrumentation to the code, which results in
increased stack usage (up to 2048 bytes and more in some cases).  It's
hard to predict how big the stack frames can be, so we disable the
warnings for KMSAN instead.

Link: https://lkml.kernel.org/r/20221024212144.2852069-3-glider@google.com
Link: https://github.com/google/kmsan/issues/89
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/Kconfig.debug |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/lib/Kconfig.debug~kconfigdebug-disable-config_frame_warn-for-kmsan-by-default
+++ a/lib/Kconfig.debug
@@ -400,8 +400,9 @@ config FRAME_WARN
 	default 1536 if (!64BIT && XTENSA)
 	default 1024 if !64BIT
 	default 2048 if 64BIT
+	default 0 if KMSAN
 	help
-	  Tell gcc to warn at build time for stack frames larger than this.
+	  Tell the compiler to warn at build time for stack frames larger than this.
 	  Setting this too low will cause a lot of warnings.
 	  Setting it to 0 disables the warning.
 
_

Patches currently in -mm which might be from glider@google.com are

mm-kmsan-export-kmsan_copy_page_meta.patch
x86-purgatory-disable-kmsan-instrumentation.patch
kconfigdebug-disable-config_frame_warn-for-kmsan-by-default.patch
x86-asm-make-sure-__put_user_size-evaluates-pointer-once.patch
x86-fortify-kmsan-fix-kmsan-fortify-builds.patch