2023-11-21 22:04:12

by Ilya Leoshkevich

Subject: [PATCH v2 05/33] kmsan: Fix is_bad_asm_addr() on arches with overlapping address spaces

Comparing pointers with TASK_SIZE does not make sense when kernel and
userspace overlap. Skip the comparison when this is the case.

Signed-off-by: Ilya Leoshkevich <[email protected]>
---
mm/kmsan/instrumentation.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/mm/kmsan/instrumentation.c b/mm/kmsan/instrumentation.c
index 470b0b4afcc4..8a1bbbc723ab 100644
--- a/mm/kmsan/instrumentation.c
+++ b/mm/kmsan/instrumentation.c
@@ -20,7 +20,8 @@

static inline bool is_bad_asm_addr(void *addr, uintptr_t size, bool is_store)
{
- if ((u64)addr < TASK_SIZE)
+ if (IS_ENABLED(CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE) &&
+ (u64)addr < TASK_SIZE)
return true;
if (!kmsan_get_metadata(addr, KMSAN_META_SHADOW))
return true;
--
2.41.0

2023-12-11 09:53:23

by Alexander Potapenko

Subject: Re: [PATCH v2 05/33] kmsan: Fix is_bad_asm_addr() on arches with overlapping address spaces

On Tue, Nov 21, 2023 at 11:02 PM Ilya Leoshkevich <[email protected]> wrote:
>
> Comparing pointers with TASK_SIZE does not make sense when kernel and
> userspace overlap. Skip the comparison when this is the case.
>
> Signed-off-by: Ilya Leoshkevich <[email protected]>
Reviewed-by: Alexander Potapenko <[email protected]>