From cd613bd699fe4652c3be24d81f4e447cd646c5b2 Mon Sep 17 00:00:00 2001 From: Ilya Leoshkevich Date: Fri, 21 Jun 2024 13:35:05 +0200 Subject: [PATCH] kmsan: accept ranges starting with 0 on s390 On s390 the virtual address 0 is valid (current CPU's lowcore is mapped there), therefore KMSAN should not complain about it. Disable the respective check on s390. There doesn't seem to be a Kconfig option to describe this situation, so explicitly check for s390. Link: https://lkml.kernel.org/r/20240621113706.315500-22-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich Reviewed-by: Alexander Potapenko Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Heiko Carstens Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim Cc: Cc: Marco Elver Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Pekka Enberg Cc: Roman Gushchin Cc: Steven Rostedt (Google) Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Signed-off-by: Andrew Morton --- mm/kmsan/init.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/mm/kmsan/init.c b/mm/kmsan/init.c index 6c56dca46063..10f52c085e6c 100644 --- a/mm/kmsan/init.c +++ b/mm/kmsan/init.c @@ -33,7 +33,10 @@ static void __init kmsan_record_future_shadow_range(void *start, void *end) bool merged = false; KMSAN_WARN_ON(future_index == NUM_FUTURE_RANGES); - KMSAN_WARN_ON((nstart >= nend) || !nstart || !nend); + KMSAN_WARN_ON((nstart >= nend) || + /* Virtual address 0 is valid on s390. */ + (!IS_ENABLED(CONFIG_S390) && !nstart) || + !nend); nstart = ALIGN_DOWN(nstart, PAGE_SIZE); nend = ALIGN(nend, PAGE_SIZE);