Andrew Morton
unread,Jun 28, 2024, 10:30:55 PM (4 days ago) Jun 28Sign in to reply to author
Sign in to forward
You do not have permission to delete messages in this group
Either email addresses are anonymous for this group or you need the view member email addresses permission to view the original message
to mm-co...@vger.kernel.org, vba...@suse.cz, sv...@linux.ibm.com, ros...@goodmis.org, roman.g...@linux.dev, rien...@google.com, pen...@kernel.org, mhir...@kernel.org, mark.r...@arm.com, kasa...@googlegroups.com, iamjoon...@lge.com, h...@linux.ibm.com, g...@linux.ibm.com, gli...@google.com, el...@google.com, dvy...@google.com, c...@linux.com, bornt...@linux.ibm.com, agor...@linux.ibm.com, 42.h...@gmail.com, i...@linux.ibm.com, ak...@linux-foundation.org
The quilt patch titled
Subject: kmsan: do not round up pg_data_t size
has been removed from the -mm tree. Its filename was
kmsan-do-not-round-up-pg_data_t-size.patch
This patch was dropped because it was merged into the mm-stable branch
of git://
git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
From: Ilya Leoshkevich <
i...@linux.ibm.com>
Subject: kmsan: do not round up pg_data_t size
Date: Fri, 21 Jun 2024 13:34:59 +0200
x86's alloc_node_data() rounds up node data size to PAGE_SIZE. It's not
explained why it's needed, but it's most likely for performance reasons,
since the padding bytes are not used anywhere. Some other architectures
do it as well, e.g., mips rounds it up to the cache line size.
kmsan_init_shadow() initializes metadata for each node data and assumes
the x86 rounding, which does not match other architectures. This may
cause the range end to overshoot the end of available memory, in turn
causing virt_to_page_or_null() in kmsan_init_alloc_meta_for_range() to
return NULL, which leads to kernel panic shortly after.
Since the padding bytes are not used, drop the rounding.
Link:
https://lkml.kernel.org/r/20240621113706...@linux.ibm.com
Signed-off-by: Ilya Leoshkevich <
i...@linux.ibm.com>
Reviewed-by: Alexander Potapenko <
gli...@google.com>
Cc: Alexander Gordeev <
agor...@linux.ibm.com>
Cc: Christian Borntraeger <
bornt...@linux.ibm.com>
Cc: Christoph Lameter <
c...@linux.com>
Cc: David Rientjes <
rien...@google.com>
Cc: Dmitry Vyukov <
dvy...@google.com>
Cc: Heiko Carstens <
h...@linux.ibm.com>
Cc: Hyeonggon Yoo <
42.h...@gmail.com>
Cc: Joonsoo Kim <
iamjoon...@lge.com>
Cc: <
kasa...@googlegroups.com>
Cc: Marco Elver <
el...@google.com>
Cc: Mark Rutland <
mark.r...@arm.com>
Cc: Masami Hiramatsu (Google) <
mhir...@kernel.org>
Cc: Pekka Enberg <
pen...@kernel.org>
Cc: Roman Gushchin <
roman.g...@linux.dev>
Cc: Steven Rostedt (Google) <
ros...@goodmis.org>
Cc: Sven Schnelle <
sv...@linux.ibm.com>
Cc: Vasily Gorbik <
g...@linux.ibm.com>
Cc: Vlastimil Babka <
vba...@suse.cz>
Signed-off-by: Andrew Morton <
ak...@linux-foundation.org>
---
mm/kmsan/init.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/kmsan/init.c~kmsan-do-not-round-up-pg_data_t-size
+++ a/mm/kmsan/init.c
@@ -72,7 +72,7 @@ static void __init kmsan_record_future_s
*/
void __init kmsan_init_shadow(void)
{
- const size_t nd_size = roundup(sizeof(pg_data_t), PAGE_SIZE);
+ const size_t nd_size = sizeof(pg_data_t);
phys_addr_t p_start, p_end;
u64 loop;
int nid;
_
Patches currently in -mm which might be from
i...@linux.ibm.com are