[PATCH v2 04/33] kmsan: Increase the maximum store size to 4096

Ilya Leoshkevich posted 33 patches 2 years ago
There is a newer version of this series
[PATCH v2 04/33] kmsan: Increase the maximum store size to 4096
Posted by Ilya Leoshkevich 2 years ago
The inline assembly block in s390's chsc() stores that much.

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
 mm/kmsan/instrumentation.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/kmsan/instrumentation.c b/mm/kmsan/instrumentation.c
index cc3907a9c33a..470b0b4afcc4 100644
--- a/mm/kmsan/instrumentation.c
+++ b/mm/kmsan/instrumentation.c
@@ -110,11 +110,10 @@ void __msan_instrument_asm_store(void *addr, uintptr_t size)
 
 	ua_flags = user_access_save();
 	/*
-	 * Most of the accesses are below 32 bytes. The two exceptions so far
-	 * are clwb() (64 bytes) and FPU state (512 bytes).
-	 * It's unlikely that the assembly will touch more than 512 bytes.
+	 * Most of the accesses are below 32 bytes. The exceptions so far are
+	 * clwb() (64 bytes), FPU state (512 bytes) and chsc() (4096 bytes).
 	 */
-	if (size > 512) {
+	if (size > 4096) {
 		WARN_ONCE(1, "assembly store size too big: %ld\n", size);
 		size = 8;
 	}
-- 
2.41.0
Re: [PATCH v2 04/33] kmsan: Increase the maximum store size to 4096
Posted by Alexander Potapenko 2 years ago
On Tue, Nov 21, 2023 at 11:07 PM Ilya Leoshkevich <iii@linux.ibm.com> wrote:
>
> The inline assembly block in s390's chsc() stores that much.
>
> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Alexander Potapenko <glider@google.com>