linux/include
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
..
acpi Merge branches 'acpi-cppc', 'acpi-video' and 'acpi-utils' 2021-04-26 17:04:27 +02:00
asm-generic vmlinux.lds.h: Avoid orphan section with !SMP 2021-06-02 12:43:55 -07:00
clocksource ARM: platform support for Apple M1 2021-04-26 12:30:36 -07:00
crypto
drm
dt-bindings dt-bindings: connector: Add PD rev 2.0 VDO definition 2021-06-04 11:43:01 +02:00
keys integrity-v5.13 2021-05-01 15:32:18 -07:00
kunit kunit: make test->lock irq safe 2021-06-29 10:53:46 -07:00
kvm
linux slub: force on no_hash_pointers when slub_debug is enabled 2021-06-29 10:53:47 -07:00
math-emu
media media updates for v5.13-rc1 2021-04-28 09:24:36 -07:00
memory
misc
net net: inline function get_net_ns_by_fd if NET_NS is disabled 2021-06-15 11:00:45 -07:00
pcmcia
ras
rdma
scsi SCSI misc on 20210428 2021-04-28 17:22:10 -07:00
soc Networking changes for 5.13. 2021-04-29 11:57:23 -07:00
sound ASoC: Fixes for v5.13 2021-05-25 08:58:01 +02:00
target
trace NFS client updates for Linux 5.13 2021-05-07 11:23:41 -07:00
uapi userfaultfd: uapi: fix UFFDIO_CONTINUE ioctl request definition 2021-06-25 10:53:26 -07:00
vdso
video
xen xen/arm: move xen_swiotlb_detect to arm/swiotlb-xen.h 2021-05-14 15:52:05 +02:00