Stephen Boyd 792702911f slub: force on no_hash_pointers when slub_debug is enabled
Obscuring the pointers that slub shows when debugging makes for some
confusing slub debug messages:

 Padding overwritten. 0x0000000079f0674a-0x000000000d4dce17

Those addresses are hashed for kernel security reasons.  If we're trying
to be secure with slub_debug on the commandline we have some big problems
given that we dump whole chunks of kernel memory to the kernel logs.
Let's force on the no_hash_pointers commandline flag when slub_debug is on
the commandline.  This makes slub debug messages more meaningful and if by
chance a kernel address is in some slub debug object dump we will have a
better chance of figuring out what went wrong.

Note that we don't use %px in the slub code because we want to reduce the
number of places that %px is used in the kernel.  This also nicely prints
a big fat warning at kernel boot if slub_debug is on the commandline so
that we know that this kernel shouldn't be used on production systems.

[akpm@linux-foundation.org: fix build with CONFIG_SLUB_DEBUG=n]

Link: https://lkml.kernel.org/r/20210601182202.3011020-5-swboyd@chromium.org
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Petr Mladek <pmladek@suse.com>
Cc: Joe Perches <joe@perches.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:47 -07:00
..
2021-06-29 10:53:46 -07:00
2020-08-09 14:10:26 -07:00
2021-04-29 11:28:08 -07:00
2020-10-30 17:34:45 +11:00
2021-04-14 16:30:30 +03:00
2021-05-06 19:24:12 -07:00
2021-05-05 12:39:29 -07:00
2018-08-16 12:14:42 -07:00
2021-01-21 14:06:00 -07:00
2021-06-05 08:58:12 -07:00
2021-01-03 20:05:18 -05:00
2020-10-20 14:39:37 -07:00
2021-04-14 16:30:30 +03:00
2021-02-26 09:41:05 -08:00
2018-10-16 13:45:44 +02:00
2021-05-06 19:24:12 -07:00
2020-06-15 18:22:43 -07:00
2019-07-11 15:17:41 -07:00
2020-12-15 22:46:16 -08:00
2018-10-15 16:31:29 -04:00
2020-12-15 22:46:16 -08:00
2021-04-28 10:01:40 -07:00
2021-02-26 09:41:05 -08:00
2021-02-26 09:41:05 -08:00