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Dmitry Vyukov 9776404388 mm: don't warn about large allocations for slab
commit 61448479a9 upstream.

Slub does not call kmalloc_slab() for sizes > KMALLOC_MAX_CACHE_SIZE,
instead it falls back to kmalloc_large().

For slab KMALLOC_MAX_CACHE_SIZE == KMALLOC_MAX_SIZE and it calls
kmalloc_slab() for all allocations relying on NULL return value for
over-sized allocations.

This inconsistency leads to unwanted warnings from kmalloc_slab() for
over-sized allocations for slab.  Returning NULL for failed allocations is
the expected behavior.

Make slub and slab code consistent by checking size >
KMALLOC_MAX_CACHE_SIZE in slab before calling kmalloc_slab().

While we are here also fix the check in kmalloc_slab().  We should check
against KMALLOC_MAX_CACHE_SIZE rather than KMALLOC_MAX_SIZE.  It all kinda
worked because for slab the constants are the same, and slub always checks
the size against KMALLOC_MAX_CACHE_SIZE before kmalloc_slab().  But if we
get there with size > KMALLOC_MAX_CACHE_SIZE anyhow bad things will
happen.  For example, in case of a newly introduced bug in slub code.

Also move the check in kmalloc_slab() from function entry to the size >
192 case.  This partially compensates for the additional check in slab
code and makes slub code a bit faster (at least theoretically).

Also drop __GFP_NOWARN in the warning check.  This warning means a bug in
slab code itself, user-passed flags have nothing to do with it.

Nothing of this affects slob.

Link: http://lkml.kernel.org/r/20180927171502.226522-1-dvyukov@gmail.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Reported-by: syzbot+87829a10073277282ad1@syzkaller.appspotmail.com
Reported-by: syzbot+ef4e8fc3a06e9019bb40@syzkaller.appspotmail.com
Reported-by: syzbot+6e438f4036df52cbb863@syzkaller.appspotmail.com
Reported-by: syzbot+8574471d8734457d98aa@syzkaller.appspotmail.com
Reported-by: syzbot+af1504df0807a083dbd9@syzkaller.appspotmail.com
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-01 09:42:51 +01:00
arch ARM: trusted_foundations: do not use naked function 2018-12-01 09:42:49 +01:00
block SCSI: fix queue cleanup race before queue initialization is done 2018-11-21 09:24:09 +01:00
certs Replace magic for trusting the secondary keyring with #define 2018-09-09 19:55:54 +02:00
crypto crypto: user - fix leaking uninitialized memory to userspace 2018-11-21 09:24:15 +01:00
Documentation x86/mm: Move LDT remap out of KASLR region on 5-level paging 2018-11-27 16:10:50 +01:00
drivers Input: synaptics - avoid using uninitialized variable when probing 2018-12-01 09:42:51 +01:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs gfs2: Don't leave s_fs_info pointing to freed memory in init_sbd 2018-12-01 09:42:51 +01:00
include netfilter: ipset: Correct rcu_dereference() call in ip_set_put_comment() 2018-11-27 16:10:48 +01:00
init init: rename and re-order boot_cpu_state_init() 2018-08-15 18:12:48 +02:00
ipc ipc/sem.c: prevent queue.status tearing in semop 2018-09-05 09:26:30 +02:00
kernel sched/core: Take the hotplug lock in sched_init_smp() 2018-11-27 16:10:49 +01:00
lib lib/raid6: Fix arm64 test build 2018-11-27 16:10:48 +01:00
mm mm: don't warn about large allocations for slab 2018-12-01 09:42:51 +01:00
net llc: do not use sk_eat_skb() 2018-12-01 09:42:51 +01:00
samples samples/bpf: Check the error of write() and read() 2018-08-24 13:09:12 +02:00
scripts kconfig: fix the rule of mainmenu_stmt symbol 2018-11-04 14:52:45 +01:00
security selinux: Add __GFP_NOWARN to allocation at str_read() 2018-12-01 09:42:50 +01:00
sound ALSA: oss: Use kvzalloc() for local buffer allocations 2018-12-01 09:42:49 +01:00
tools tools/power/cpupower: fix compilation with STATIC=true 2018-12-01 09:42:50 +01:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM: arm64: Fix caching of host MDCR_EL2 value 2018-11-13 11:15:08 -08:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS MAINTAINERS: Add Sasha as a stable branch maintainer 2018-12-01 09:42:50 +01:00
Makefile Linux 4.14.84 2018-11-27 16:10:52 +01:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.