lkml.org 
[lkml]   [2022]   [Oct]   [18]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH AUTOSEL 5.4 10/13] kmsan: disable physical page merging in biovec
From
On 10/18/22 02:22, Eric Biggers wrote:
> On Mon, Oct 17, 2022 at 08:10:59PM -0400, Sasha Levin wrote:
>> From: Alexander Potapenko <glider@google.com>
>>
>> [ Upstream commit f630a5d0ca59a6e73b61e3f82c371dc230da99ff ]
>>
>> KMSAN metadata for adjacent physical pages may not be adjacent, therefore
>> accessing such pages together may lead to metadata corruption. We disable
>> merging pages in biovec to prevent such corruptions.
>>
>> Link: https://lkml.kernel.org/r/20220915150417.722975-28-glider@google.com
>> Signed-off-by: Alexander Potapenko <glider@google.com>
>> Cc: Alexander Viro <viro@zeniv.linux.org.uk>
>> Cc: Alexei Starovoitov <ast@kernel.org>
>> Cc: Andrey Konovalov <andreyknvl@gmail.com>
>> Cc: Andrey Konovalov <andreyknvl@google.com>
>> Cc: Andy Lutomirski <luto@kernel.org>
>> Cc: Arnd Bergmann <arnd@arndb.de>
>> Cc: Borislav Petkov <bp@alien8.de>
>> Cc: Christoph Hellwig <hch@lst.de>
>> Cc: Christoph Lameter <cl@linux.com>
>> Cc: David Rientjes <rientjes@google.com>
>> Cc: Dmitry Vyukov <dvyukov@google.com>
>> Cc: Eric Biggers <ebiggers@google.com>
>> Cc: Eric Biggers <ebiggers@kernel.org>
>> Cc: Eric Dumazet <edumazet@google.com>
>> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
>> Cc: Herbert Xu <herbert@gondor.apana.org.au>
>> Cc: Ilya Leoshkevich <iii@linux.ibm.com>
>> Cc: Ingo Molnar <mingo@redhat.com>
>> Cc: Jens Axboe <axboe@kernel.dk>
>> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
>> Cc: Kees Cook <keescook@chromium.org>
>> Cc: Marco Elver <elver@google.com>
>> Cc: Mark Rutland <mark.rutland@arm.com>
>> Cc: Matthew Wilcox <willy@infradead.org>
>> Cc: Michael S. Tsirkin <mst@redhat.com>
>> Cc: Pekka Enberg <penberg@kernel.org>
>> Cc: Peter Zijlstra <peterz@infradead.org>
>> Cc: Petr Mladek <pmladek@suse.com>
>> Cc: Stephen Rothwell <sfr@canb.auug.org.au>
>> Cc: Steven Rostedt <rostedt@goodmis.org>
>> Cc: Thomas Gleixner <tglx@linutronix.de>
>> Cc: Vasily Gorbik <gor@linux.ibm.com>
>> Cc: Vegard Nossum <vegard.nossum@oracle.com>
>> Cc: Vlastimil Babka <vbabka@suse.cz>
>> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
>> Signed-off-by: Sasha Levin <sashal@kernel.org>
>> ---
>> block/blk.h | 7 +++++++
>> 1 file changed, 7 insertions(+)
>>
>> diff --git a/block/blk.h b/block/blk.h
>> index ee3d5664d962..3358ef4244fe 100644
>> --- a/block/blk.h
>> +++ b/block/blk.h
>> @@ -79,6 +79,13 @@ static inline bool biovec_phys_mergeable(struct request_queue *q,
>> phys_addr_t addr1 = page_to_phys(vec1->bv_page) + vec1->bv_offset;
>> phys_addr_t addr2 = page_to_phys(vec2->bv_page) + vec2->bv_offset;
>>
>> + /*
>> + * Merging adjacent physical pages may not work correctly under KMSAN
>> + * if their metadata pages aren't adjacent. Just disable merging.
>> + */
>> + if (IS_ENABLED(CONFIG_KMSAN))
>> + return false;
>> +
>> if (addr1 + vec1->bv_len != addr2)
>> return false;
>> if (xen_domain() && !xen_biovec_phys_mergeable(vec1, vec2->bv_page))
>
> So KMSAN is being backported to 5.4?

No, AUTOSEL is drunk and should drop the random kmsan patches for random
stable versions.

> - Eric

\
 
 \ /
  Last update: 2022-10-18 11:25    [W:0.142 / U:0.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site