From 79dbd006a6d6f51777ba4948046561b6d9270504 Mon Sep 17 00:00:00 2001
From: Alexander Potapenko <glider@google.com>
Date: Thu, 15 Sep 2022 17:03:46 +0200
Subject: [PATCH] kmsan: disable instrumentation of unsupported common kernel
 code

EFI stub cannot be linked with KMSAN runtime, so we disable
instrumentation for it.

Instrumenting kcov, stackdepot or lockdep leads to infinite recursion
caused by instrumentation hooks calling instrumented code again.

Link: https://lkml.kernel.org/r/20220915150417.722975-13-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Eric Biggers <ebiggers@google.com>
Cc: Eric Biggers <ebiggers@kernel.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vegard Nossum <vegard.nossum@oracle.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 drivers/firmware/efi/libstub/Makefile | 1 +
 kernel/Makefile                       | 1 +
 kernel/locking/Makefile               | 3 ++-
 lib/Makefile                          | 3 +++
 4 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/firmware/efi/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile
index d0537573501e..81432d0c904b 100644
--- a/drivers/firmware/efi/libstub/Makefile
+++ b/drivers/firmware/efi/libstub/Makefile
@@ -46,6 +46,7 @@ GCOV_PROFILE			:= n
 # Sanitizer runtimes are unavailable and cannot be linked here.
 KASAN_SANITIZE			:= n
 KCSAN_SANITIZE			:= n
+KMSAN_SANITIZE			:= n
 UBSAN_SANITIZE			:= n
 OBJECT_FILES_NON_STANDARD	:= y
 
diff --git a/kernel/Makefile b/kernel/Makefile
index 318789c728d3..d754e0be1176 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -38,6 +38,7 @@ KCOV_INSTRUMENT_kcov.o := n
 KASAN_SANITIZE_kcov.o := n
 KCSAN_SANITIZE_kcov.o := n
 UBSAN_SANITIZE_kcov.o := n
+KMSAN_SANITIZE_kcov.o := n
 CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector
 
 # Don't instrument error handlers
diff --git a/kernel/locking/Makefile b/kernel/locking/Makefile
index d51cabf28f38..ea925731fa40 100644
--- a/kernel/locking/Makefile
+++ b/kernel/locking/Makefile
@@ -5,8 +5,9 @@ KCOV_INSTRUMENT		:= n
 
 obj-y += mutex.o semaphore.o rwsem.o percpu-rwsem.o
 
-# Avoid recursion lockdep -> KCSAN -> ... -> lockdep.
+# Avoid recursion lockdep -> sanitizer -> ... -> lockdep.
 KCSAN_SANITIZE_lockdep.o := n
+KMSAN_SANITIZE_lockdep.o := n
 
 ifdef CONFIG_FUNCTION_TRACER
 CFLAGS_REMOVE_lockdep.o = $(CC_FLAGS_FTRACE)
diff --git a/lib/Makefile b/lib/Makefile
index d7d94102991b..42e185cdecd0 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -270,6 +270,9 @@ obj-$(CONFIG_POLYNOMIAL) += polynomial.o
 CFLAGS_stackdepot.o += -fno-builtin
 obj-$(CONFIG_STACKDEPOT) += stackdepot.o
 KASAN_SANITIZE_stackdepot.o := n
+# In particular, instrumenting stackdepot.c with KMSAN will result in infinite
+# recursion.
+KMSAN_SANITIZE_stackdepot.o := n
 KCOV_INSTRUMENT_stackdepot.o := n
 
 obj-$(CONFIG_REF_TRACKER) += ref_tracker.o