diff mbox series

[v2,31/48] kernel: kmsan: don't instrument stacktrace.c

Message ID 20220329124017.737571-32-glider@google.com (mailing list archive)
State New
Headers show
Series Add KernelMemorySanitizer infrastructure | expand

Commit Message

Alexander Potapenko March 29, 2022, 12:40 p.m. UTC 
When unwinding stack traces, the kernel may pick uninitialized data from
the stack. To avoid false reports on that data, we do not instrument
stacktrace.c

Signed-off-by: Alexander Potapenko <glider@google.com>
---
Link: https://linux-review.googlesource.com/id/Iadb72036ff6868b1d7c9f1ed6630a66be6c57a42
---
 kernel/Makefile | 5 +++++
 1 file changed, 5 insertions(+)

Comments

Alexander Potapenko April 4, 2022, 2:56 p.m. UTC | #1 
On Tue, Mar 29, 2022 at 2:41 PM Alexander Potapenko <glider@google.com> wrote:
>
> When unwinding stack traces, the kernel may pick uninitialized data from
> the stack. To avoid false reports on that data, we do not instrument
> stacktrace.c

This patch is not needed anymore if we unpoison the stack traces
passed to __stack_depot_save() from KMSAN core.
diff mbox series

Patch

diff --git a/kernel/Makefile b/kernel/Makefile
index 80f6cfb60c020..1147f0bd6e022 100644
--- a/kernel/Makefile
+++ b/kernel/Makefile
@@ -40,6 +40,11 @@  KASAN_SANITIZE_kcov.o := n
 KCSAN_SANITIZE_kcov.o := n
 UBSAN_SANITIZE_kcov.o := n
 KMSAN_SANITIZE_kcov.o := n
+
+# Code in stactrace.c may branch on random values taken from the stack.
+# Prevent KMSAN false positives by not instrumenting this file.
+KMSAN_SANITIZE_stacktrace.o := n
+
 CFLAGS_kcov.o := $(call cc-option, -fno-conserve-stack) -fno-stack-protector
 
 # Don't instrument error handlers