Commit Graph

702902 Commits

Author SHA1 Message Date
Alexey Dobriyan
f22ef333c3 cpumask: make cpumask_next() out-of-line
Every for_each_XXX_cpu() invocation calls cpumask_next() which is an
inline function:

	static inline unsigned int cpumask_next(int n, const struct cpumask *srcp)
	{
	        /* -1 is a legal arg here. */
	        if (n != -1)
	                cpumask_check(n);
	        return find_next_bit(cpumask_bits(srcp), nr_cpumask_bits, n + 1);
	}

However!

find_next_bit() is regular out-of-line function which means "nr_cpu_ids"
load and increment happen at the caller resulting in a lot of bloat

x86_64 defconfig:
	add/remove: 3/0 grow/shrink: 8/373 up/down: 155/-5668 (-5513)
x86_64 allyesconfig-ish:
	add/remove: 3/1 grow/shrink: 57/634 up/down: 3515/-28177 (-24662) !!!

Some archs redefine find_next_bit() but it is OK:

	m68k		inline but SMP is not supported
	arm		out-of-line
	unicore32	out-of-line

Function call will happen anyway, so move load and increment into callee.

Link: http://lkml.kernel.org/r/20170824230010.GA1593@avx2
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:51 -07:00
Luis R. Rodriguez
0ce2c20293 kmod: move #ifdef CONFIG_MODULES wrapper to Makefile
The entire file is now conditionally compiled only when CONFIG_MODULES is
enabled, and this this is a bool.  Just move this conditional to the
Makefile as its easier to read this way.

Link: http://lkml.kernel.org/r/20170810180618.22457-5-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:51 -07:00
Luis R. Rodriguez
c1f3fa2a4f kmod: split off umh headers into its own file
In the future usermode helper users do not need to carry in all the of
kmod headers declarations.

Since kmod.h still includes umh.h this change has no functional changes,
each umh user can be cleaned up separately later and with time.

Link: http://lkml.kernel.org/r/20170810180618.22457-4-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:51 -07:00
Luis R. Rodriguez
00653d3aba MAINTAINERS: clarify kmod is just a kernel module loader
This should make it clearer what the kmod code is now that
the umh code is split out separately.

Link: http://lkml.kernel.org/r/20170810180618.22457-3-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Luis R. Rodriguez
235586939d kmod: split out umh code into its own file
Patch series "kmod: few code cleanups to split out umh code"

The usermode helper has a provenance from the old usb code which first
required a usermode helper.  Eventually this was shoved into kmod.c and
the kernel's modprobe calls was converted over eventually to share the
same code.  Over time the list of usermode helpers in the kernel has grown
-- so kmod is just but one user of the API.

This series is a simple logical cleanup which acknowledges the code
evolution of the usermode helper and shoves the UMH API into its own
dedicated file.  This way users of the API can later just include umh.h
instead of kmod.h.

Note despite the diff state the first patch really is just a code shove,
no functional changes are done there.  I did use git format-patch -M to
generate the patch, but in the end the split was not enough for git to
consider it a rename hence the large diffstat.

I've put this through 0-day and it gives me their machine compilation
blessings with all tests as OK.

This patch (of 4):

There's a slew of usermode helper users and kmod is just one of them.
Split out the usermode helper code into its own file to keep the logic and
focus split up.

This change provides no functional changes.

Link: http://lkml.kernel.org/r/20170810180618.22457-2-mcgrof@kernel.org
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: Daniel Mentz <danielmentz@google.com>
Cc: David Binderman <dcb314@hotmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Dan Carpenter
52c270d358 test_kmod: flip INT checks to be consistent
Most checks will check for min and then max, except the int check.  Flip
the checks to be consistent with the other code.

[mcgrof@kernel.org: massaged commit log]
Link: http://lkml.kernel.org/r/20170802211707.28020-3-mcgrof@kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: David Binderman <dcb314@hotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Dan Carpenter
f520409cfd test_kmod: remove paranoid UINT_MAX check on uint range processing
The UINT_MAX comparison is not needed because "max" is already an unsigned
int, and we expect developer C code max value input to have a sensible 0 -
UINT_MAX range.  Note that if it so happens to be UINT_MAX + 1 it would
lead to an issue, but we expect the developer to know this.

[mcgrof@kernel.org: massaged commit log]
Link: http://lkml.kernel.org/r/20170802211707.28020-2-mcgrof@kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Jessica Yu <jeyu@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Michal Marek <mmarek@suse.com>
Cc: Petr Mladek <pmladek@suse.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Colin Ian King <colin.king@canonical.com>
Cc: David Binderman <dcb314@hotmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
OGAWA Hirofumi
5680db4b66 vfat: deduplicate hex2bin()
We may use hex2bin() instead of custom approach.

Link: http://lkml.kernel.org/r/87zibktpil.fsf@devron
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Tomohiro Kusumi
b9fa2ad1ed autofs: use unsigned int/long instead of uint/ulong for ioctl args
The standard types unsigned int and unsigned long should be used for
.compat_ioctl.  autofs is the only fs using uing/ulong for this, and these
are even the only uint/ulong in the entire autofs code.

Drop unneeded long cast in return value of autofs_dev_ioctl_compat().
It's already long.

Link: http://lkml.kernel.org/r/150285069709.4670.3884827966280147529.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Tomohiro Kusumi
7ed1da84b3 autofs: drop wrong comment
This comment was correct when it was added in 8d7b48e0 ("autofs4: add
miscellaneous device for ioctls") in 2008, but not after 4e44b685 "Get rid
of path_lookup in autofs4" in 2009 which introduced find_autofs_mount().

Link: http://lkml.kernel.org/r/150285069148.4670.17959501481201077445.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Tomohiro Kusumi
718b303b49 autofs: use AUTOFS_DEV_IOCTL_SIZE
Use a macro which defines misc-dev ioctl parameter size (excluding a path
beyond &path[0]) since it's been used to initialize and copy this
structure ever since it first appeared in 8d7b48e0 in 2008.

(or simply get rid of this if this is just unnecessary abstraction when
all it needs is sizeof(struct autofs_dev_ioctl))

Edit: raven@themaw.net
That's a good point but I'd prefer to keep the macro define.
End edit: raven@themaw.net

Link: http://lkml.kernel.org/r/150285068577.4670.2599968823770600622.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Tomohiro Kusumi
ed837d0901 autofs: non functional header inclusion cleanup
Having header includes before any macro (without any dependency) simply
looks normal.  No reason to have these macros in between.

Link: http://lkml.kernel.org/r/150285068011.4670.10271483982093996996.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Tomohiro Kusumi
1f28c5d055 autofs: remove unused AUTOFS_IOC_EXPIRE_DIRECT/INDIRECT
These are not used by either kernel or userspace, although
AUTOFS_IOC_EXPIRE_DIRECT once seems to have been used by userspace in
around 2006-2008, which was technically just an alias of the existing
ioctl AUTOFS_IOC_EXPIRE_MULTI.

ioctls for autofs are already complicated enough that they could be
removed unless these are staying here to be able to compile userspace code
of certain period of time from a decade ago.

Edit: raven@themaw.net
Yes, this is indeed very old and anything that still uses must
be updated becuase it will be using broken functionality.
End edit: raven@themaw.net

Link: http://lkml.kernel.org/r/150285067347.4670.11494624644273072003.stgit@pluto.themaw.net
Signed-off-by: Tomohiro Kusumi <tkusumi@tuxera.com>
Signed-off-by: Ian Kent <raven@themaw.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Ian Kent
3dd8f7c3b7 autofs: make dev ioctl version and ismountpoint user accessible
Some of the autofs miscellaneous device ioctls need to be accessable to
user space applications without CAP_SYS_ADMIN to get information about
autofs mounts.

Link: http://lkml.kernel.org/r/150216642517.11652.2338933266137331637.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Colin Walters <walters@redhat.com>
Cc: Ondrej Holy <oholy@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Ian Kent
e54c7bcbf1 autofs: make disc device user accessible
The autofs miscellanous device ioctls that shouldn't require
CAP_SYS_ADMIN need to be accessible to user space applications in order
to be able to get information about autofs mounts.

The module checks capabilities so the miscelaneous device should be fine
with broad permissions.

Link: http://lkml.kernel.org/r/150216641928.11652.7388977863125547969.stgit@pluto.themaw.net
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Colin Walters <walters@redhat.com>
Cc: Ondrej Holy <oholy@redhat.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Ian Kent
42f4614821 autofs: fix AT_NO_AUTOMOUNT not being honored
The fstatat(2) and statx() calls can pass the flag AT_NO_AUTOMOUNT which
is meant to clear the LOOKUP_AUTOMOUNT flag and prevent triggering of an
automount by the call.  But this flag is unconditionally cleared for all
stat family system calls except statx().

stat family system calls have always triggered mount requests for the
negative dentry case in follow_automount() which is intended but prevents
the fstatat(2) and statx() AT_NO_AUTOMOUNT case from being handled.

In order to handle the AT_NO_AUTOMOUNT for both system calls the negative
dentry case in follow_automount() needs to be changed to return ENOENT
when the LOOKUP_AUTOMOUNT flag is clear (and the other required flags are
clear).

AFAICT this change doesn't have any noticable side effects and may, in
some use cases (although I didn't see it in testing) prevent unnecessary
callbacks to the automount daemon.

It's also possible that a stat family call has been made with a path that
is in the process of being mounted by some other process.  But stat family
calls should return the automount state of the path as it is "now" so it
shouldn't wait for mount completion.

This is the same semantic as the positive dentry case already handled.

Link: http://lkml.kernel.org/r/150216641255.11652.4204561328197919771.stgit@pluto.themaw.net
Fixes: deccf497d8 ("Make stat/lstat/fstatat pass AT_NO_AUTOMOUNT to vfs_statx()")
Signed-off-by: Ian Kent <raven@themaw.net>
Cc: David Howells <dhowells@redhat.com>
Cc: Colin Walters <walters@redhat.com>
Cc: Ondrej Holy <oholy@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Daniel Micay
33d72f3822 init/main.c: extract early boot entropy from the passed cmdline
Feed the boot command-line as to the /dev/random entropy pool

Existing Android bootloaders usually pass data which may not be known by
an external attacker on the kernel command-line.  It may also be the
case on other embedded systems.  Sample command-line from a Google Pixel
running CopperheadOS....

    console=ttyHSL0,115200,n8 androidboot.console=ttyHSL0
    androidboot.hardware=sailfish user_debug=31 ehci-hcd.park=3
    lpm_levels.sleep_disabled=1 cma=32M@0-0xffffffff buildvariant=user
    veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab
    androidboot.bootdevice=624000.ufshc androidboot.verifiedbootstate=yellow
    androidboot.veritymode=enforcing androidboot.keymaster=1
    androidboot.serialno=FA6CE0305299 androidboot.baseband=msm
    mdss_mdp.panel=1:dsi:0:qcom,mdss_dsi_samsung_ea8064tg_1080p_cmd:1:none:cfg:single_dsi
    androidboot.slot_suffix=_b fpsimd.fpsimd_settings=0
    app_setting.use_app_setting=0 kernelflag=0x00000000 debugflag=0x00000000
    androidboot.hardware.revision=PVT radioflag=0x00000000
    radioflagex1=0x00000000 radioflagex2=0x00000000 cpumask=0x00000000
    androidboot.hardware.ddr=4096MB,Hynix,LPDDR4 androidboot.ddrinfo=00000006
    androidboot.ddrsize=4GB androidboot.hardware.color=GRA00
    androidboot.hardware.ufs=32GB,Samsung androidboot.msm.hw_ver_id=268824801
    androidboot.qf.st=2 androidboot.cid=11111111 androidboot.mid=G-2PW4100
    androidboot.bootloader=8996-012001-1704121145
    androidboot.oem_unlock_support=1 androidboot.fp_src=1
    androidboot.htc.hrdump=detected androidboot.ramdump.opt=mem@2g:2g,mem@4g:2g
    androidboot.bootreason=reboot androidboot.ramdump_enable=0 ro
    root=/dev/dm-0 dm="system none ro,0 1 android-verity /dev/sda34"
    rootwait skip_initramfs init=/init androidboot.wificountrycode=US
    androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136

Among other things, it contains a value unique to the device
(androidboot.serialno=FA6CE0305299), unique to the OS builds for the
device variant (veritykeyid=id:dfcb9db0089e5b3b4090a592415c28e1cb4545ab)
and timings from the bootloader stages in milliseconds
(androidboot.boottime=1BLL:85,1BLE:669,2BLL:0,2BLE:1777,SW:6,KL:8136).

[tytso@mit.edu: changelog tweak]
[labbott@redhat.com: line-wrapped command line]
Link: http://lkml.kernel.org/r/20170816231458.2299-3-labbott@redhat.com
Signed-off-by: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Laura Abbott <lauraa@codeaurora.org>
Cc: Nick Kralevich <nnk@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Laura Abbott
121388a313 init: move stack canary initialization after setup_arch
Patch series "Command line randomness", v3.

A series to add the kernel command line as a source of randomness.

This patch (of 2):

Stack canary intialization involves getting a random number.  Getting this
random number may involve accessing caches or other architectural specific
features which are not available until after the architecture is setup.
Move the stack canary initialization later to accommodate this.

Link: http://lkml.kernel.org/r/20170816231458.2299-2-labbott@redhat.com
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Laura Abbott <labbott@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Daniel Micay <danielmicay@gmail.com>
Cc: Nick Kralevich <nnk@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Markus Elfring
9367bb730e binfmt_flat: delete two error messages for a failed memory allocation in decompress_exec()
Omit extra messages for a memory allocation failure in this function.

This issue was detected by using the Coccinelle software.

Link: http://lkml.kernel.org/r/f92aac79-b05e-321a-1a19-d38c7159ee9c@users.sourceforge.net
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Jean Delvare
0547fa5851 checkpatch: add 6 missing types to --list-types
Unlike all other types, LONG_LINE, LONG_LINE_COMMENT and LONG_LINE_STRING
are passed to WARN() through a variable.  This causes the parser in
list_types() to miss them and consequently they are not present in the
output of --list-types.

Additionally, types TYPO_SPELLING, FSF_MAILING_ADDRESS and AVOID_BUG are
passed with a variable level, causing the parser to miss them too.

So modify the regex to also catch these special cases.

Link: http://lkml.kernel.org/r/20170902175610.7e4a7c9d@endymion
Fixes: 3beb42eced ("checkpatch: add --list-types to show message types to show or ignore")
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Jean Delvare
0675a8fbd7 checkpatch: rename variables to avoid confusion
The variable name "$msg_type" is sometimes used to set the message type,
and sometimes used to set the message level.  This works but is kind of
confusing.  Use "$msg_level" in the latter case instead, to make the code
clearer.

Link: http://lkml.kernel.org/r/20170902175345.175db33a@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Jean Delvare
ab1ecabf4f checkpatch: fix typo in comment
Link: http://lkml.kernel.org/r/20170902175249.15bb77f2@endymion
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Joe Perches
63b7c73ec8 checkpatch: add --strict check for ifs with unnecessary parentheses
An if statement test like
	if ((foo == bar) && (baz != qux))
can arguably be better written without the parentheses as
	if (foo == bar && baz != qux)

Add a test to find these cases.

Link: http://lkml.kernel.org/r/dcd0561ddd0fa43c51a420d53b550d738bf42001.1502734458.git.joe@perches.com
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:50 -07:00
Takashi Iwai
afdb05e9d6 lib/oid_registry.c: X.509: fix the buffer overflow in the utility function for OID string
The sprint_oid() utility function doesn't properly check the buffer size
that it causes that the warning in vsnprintf() be triggered.  For
example on v4.1 kernel:

  ------------[ cut here ]------------
  WARNING: CPU: 0 PID: 2357 at lib/vsprintf.c:1867 vsnprintf+0x5a7/0x5c0()
  ...

We can trigger this issue by injecting maliciously crafted x509 cert in
DER format.  Just using hex editor to change the length of OID to over
the length of the SEQUENCE container.  For example:

    0:d=0  hl=4 l= 980 cons: SEQUENCE
    4:d=1  hl=4 l= 700 cons:  SEQUENCE
    8:d=2  hl=2 l=   3 cons:   cont [ 0 ]
   10:d=3  hl=2 l=   1 prim:    INTEGER           :02
   13:d=2  hl=2 l=   9 prim:   INTEGER           :9B47FAF791E7D1E3
   24:d=2  hl=2 l=  13 cons:   SEQUENCE
   26:d=3  hl=2 l=   9 prim:    OBJECT            :sha256WithRSAEncryption
   37:d=3  hl=2 l=   0 prim:    NULL
   39:d=2  hl=2 l= 121 cons:   SEQUENCE
   41:d=3  hl=2 l=  22 cons:    SET
   43:d=4  hl=2 l=  20 cons:     SEQUENCE      <=== the SEQ length is 20
   45:d=5  hl=2 l=   3 prim:      OBJECT            :organizationName
	<=== the original length is 3, change the length of OID to over the length of SEQUENCE

Pawel Wieczorkiewicz reported this problem and Takashi Iwai provided
patch to fix it by checking the bufsize in sprint_oid().

Link: http://lkml.kernel.org/r/20170903021646.2080-1-jlee@suse.com
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: "Lee, Chun-Yi" <jlee@suse.com>
Reported-by: Pawel Wieczorkiewicz <pwieczorkiewicz@suse.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Pawel Wieczorkiewicz <pwieczorkiewicz@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Eric Dumazet
bc9ae2247a radix-tree: must check __radix_tree_preload() return value
__radix_tree_preload() only disables preemption if no error is returned.

So we really need to make sure callers always check the return value.

idr_preload() contract is to always disable preemption, so we need
to add a missing preempt_disable() if an error happened.

Similarly, ida_pre_get() only needs to call preempt_enable() in the
case no error happened.

Link: http://lkml.kernel.org/r/1504637190.15310.62.camel@edumazet-glaptop3.roam.corp.google.com
Fixes: 0a835c4f09 ("Reimplement IDR and IDA using the radix tree")
Fixes: 7ad3d4d85c ("ida: Move ida_bitmap to a percpu variable")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org>    [4.11+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Baoquan He
7c61bd6983 lib/cmdline.c: remove meaningless comment
One line of code was commented out by c++ style comment for debugging, but
forgot removing it.

Clean it up.

Link: http://lkml.kernel.org/r/1503312113-11843-1-git-send-email-bhe@redhat.com
Signed-off-by: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Dan Carpenter
da43652826 lib/string.c: check for kmalloc() failure
This is mostly to keep the number of static checker warnings down so we
can spot new bugs instead of them being drowned in noise.  This function
doesn't return normal kernel error codes but instead the return value is
used to display exactly which memory failed.  I chose -1 as hopefully
that's a helpful thing to print.

Link: http://lkml.kernel.org/r/20170817115420.uikisjvfmtrqkzjn@mwanda
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Kees Cook <keescook@chromium.org>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Cc: Daniel Micay <danielmicay@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
895a60728f lib/rhashtable: fix comment on locks_mul default value
As of commit 4cf0b354d9 ("rhashtable: avoid large lock-array
allocations"), the default value for the locks multiplier was reduced
from 128 to 32.

Update the header file to reflect this.

Link: http://lkml.kernel.org/r/20170815215401.30745-1-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Florian Westphal <fw@strlen.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Yury Norov
60ef690018 bitmap: introduce BITMAP_FROM_U64()
The macro is the compile-time analogue of bitmap_from_u64() with the same
purpose: convert the 64-bit number to the properly ordered pair of 32-bit
parts, suitable for filling the bitmap in 32-bit BE environment.

Use it to make test_bitmap_parselist() correct for 32-bit BE ABIs.

Tested on BE mips/qemu.

[akpm@linux-foundation.org: tweak code comment]
Link: http://lkml.kernel.org/r/20170810172916.24144-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Cc: Noam Camus <noamca@mellanox.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Yury Norov
6df0d464db lib/test_bitmap.c: add test for bitmap_parselist()
Do some basic checks for bitmap_parselist().

[akpm@linux-foundation.org: fix printk warning]
Link: http://lkml.kernel.org/r/20170807225438.16161-2-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Cc: Noam Camus <noamca@mellanox.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Yury Norov
0a5ce0831d lib/bitmap.c: make bitmap_parselist() thread-safe and much faster
Current implementation of bitmap_parselist() uses a static variable to
save local state while setting bits in the bitmap.  It is obviously wrong
if we assume execution in multiprocessor environment.  Fortunately, it's
possible to rewrite this portion of code to avoid using the static
variable.

It is also possible to set bits in the mask per-range with bitmap_set(),
not per-bit, as it is implemented now, with set_bit(); which is way
faster.

The important side effect of this change is that setting bits in this
function from now is not per-bit atomic and less memory-ordered.  This is
because set_bit() guarantees the order of memory accesses, while
bitmap_set() does not.  I think that it is the advantage of the new
approach, because the bitmap_parselist() is intended to initialise bit
arrays, and user should protect the whole bitmap during initialisation if
needed.  So protecting individual bits looks expensive and useless.  Also,
other range-oriented functions in lib/bitmap.c don't worry much about
atomicity.

With all that, setting 2k bits in map with the pattern like 0-2047:128/256
becomes ~50 times faster after applying the patch in my testing
environment (arm64 hosted on qemu).

The second patch of the series adds the test for bitmap_parselist().  It's
not intended to cover all tricky cases, just to make sure that I didn't
screw up during rework.

Link: http://lkml.kernel.org/r/20170807225438.16161-1-ynorov@caviumnetworks.com
Signed-off-by: Yury Norov <ynorov@caviumnetworks.com>
Cc: Noam Camus <noamca@mellanox.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Florian Fainelli
e4dace3615 lib: add test module for CONFIG_DEBUG_VIRTUAL
Add a test module that allows testing that CONFIG_DEBUG_VIRTUAL works
correctly, at least that it can catch invalid calls to virt_to_phys()
against the non-linear kernel virtual address map.

Link: http://lkml.kernel.org/r/20170808164035.26725-1-f.fainelli@gmail.com
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Cc: "Luis R. Rodriguez" <mcgrof@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Andy Shevchenko
9888a588ea lib/hexdump.c: return -EINVAL in case of error in hex2bin()
In some cases caller would like to use error code directly without
shadowing.

-EINVAL feels a rightful code to return in case of error in hex2bin().

Link: http://lkml.kernel.org/r/20170731135510.68023-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
f0f1a45f95 block/cfq: cache rightmost rb_node
For the same reasons we already cache the leftmost pointer, apply the same
optimization for rb_last() calls.  Users must explicitly do this as
rb_root_cached only deals with the smallest node.

[dave@stgolabs.net: brain fart #1]
  Link: http://lkml.kernel.org/r/20170731155955.GD21328@linux-80c1.suse
Link: http://lkml.kernel.org/r/20170719014603.19029-18-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
fa90b2fd30 mem/memcg: cache rightmost node
Such that we can optimize __mem_cgroup_largest_soft_limit_node().  The
only overhead is the extra footprint for the cached pointer, but this
should not be an issue for mem_cgroup_tree_per_node.

[dave@stgolabs.net: brain fart #2]
  Link: http://lkml.kernel.org/r/20170731160114.GE21328@linux-80c1.suse
Link: http://lkml.kernel.org/r/20170719014603.19029-17-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
b2ac2ea629 fs/epoll: use faster rb_first_cached()
...  such that we can avoid the tree walks to get the node with the
smallest key.  Semantically the same, as the previously used rb_first(),
but O(1).  The main overhead is the extra footprint for the cached rb_node
pointer, which should not matter for epoll.

Link: http://lkml.kernel.org/r/20170719014603.19029-15-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
410bd5ecb2 procfs: use faster rb_first_cached()
...  such that we can avoid the tree walks to get the node with the
smallest key.  Semantically the same, as the previously used rb_first(),
but O(1).  The main overhead is the extra footprint for the cached rb_node
pointer, which should not matter for procfs.

Link: http://lkml.kernel.org/r/20170719014603.19029-14-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
f2686bb486 lib/interval-tree: correct comment wrt generic flavor
interval_tree.h _is_ the generic flavor.

Link: http://lkml.kernel.org/r/20170719014603.19029-13-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
f808c13fd3 lib/interval_tree: fast overlap detection
Allow interval trees to quickly check for overlaps to avoid unnecesary
tree lookups in interval_tree_iter_first().

As of this patch, all interval tree flavors will require using a
'rb_root_cached' such that we can have the leftmost node easily
available.  While most users will make use of this feature, those with
special functions (in addition to the generic insert, delete, search
calls) will avoid using the cached option as they can do funky things
with insertions -- for example, vma_interval_tree_insert_after().

[jglisse@redhat.com: fix deadlock from typo vm_lock_anon_vma()]
  Link: http://lkml.kernel.org/r/20170808225719.20723-1-jglisse@redhat.com
Link: http://lkml.kernel.org/r/20170719014603.19029-12-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Doug Ledford <dledford@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Christian Benvenuti <benve@cisco.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
09663c86e2 block/cfq: replace cfq_rb_root leftmost caching
... with the generic rbtree flavor instead. No changes
in semantics whatsoever.

Link: http://lkml.kernel.org/r/20170719014603.19029-11-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Jens Axboe <axboe@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
a23ba907d5 locking/rtmutex: replace top-waiter and pi_waiters leftmost caching
... with the generic rbtree flavor instead. No changes
in semantics whatsoever.

Link: http://lkml.kernel.org/r/20170719014603.19029-10-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
2161573ecd sched/deadline: replace earliest dl and rq leftmost caching
... with the generic rbtree flavor instead. No changes
in semantics whatsoever.

Link: http://lkml.kernel.org/r/20170719014603.19029-9-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:49 -07:00
Davidlohr Bueso
bfb068892d sched/fair: replace cfs_rq->rb_leftmost
... with the generic rbtree flavor instead. No changes
in semantics whatsoever.

Link: http://lkml.kernel.org/r/20170719014603.19029-8-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Davidlohr Bueso
b10d43f989 lib/rbtree_test.c: support rb_root_cached
We can work with a single rb_root_cached root to test both cached and
non-cached rbtrees.  In addition, also add a test to measure latencies
between rb_first and its fast counterpart.

Link: http://lkml.kernel.org/r/20170719014603.19029-7-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Davidlohr Bueso
977bd8d5e1 lib/rbtree_test.c: add (inorder) traversal test
This adds a second test for regular rb-tree testing in that there is no
need to repeat it for the augmented flavor.

Link: http://lkml.kernel.org/r/20170719014603.19029-6-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Davidlohr Bueso
223f8911ea lib/rbtree_test.c: make input module parameters
Allows for more flexible debugging.

Link: http://lkml.kernel.org/r/20170719014603.19029-5-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Davidlohr Bueso
35dc67d7d9 rbtree: add some additional comments for rebalancing cases
While overall the code is very nicely commented, it might not be
immediately obvious from the diagrams what is going on.  Add a very
brief summary of each case.  Opposite cases where the node is the left
child are left untouched.

Link: http://lkml.kernel.org/r/20170719014603.19029-4-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Davidlohr Bueso
2aadf7fc7d rbtree: optimize root-check during rebalancing loop
The only times the nil-parent (root node) condition is true is when the
node is the first in the tree, or after fixing rbtree rule #4 and the
case 1 rebalancing made the node the root.  Such conditions do not apply
most of the time:

(i) The common case in an rbtree is to have more than a single node,
    so this is only true for the first rb_insert().

(ii) While there is a chance only one first rotation is needed, cases
    where the node's uncle is black (cases 2,3) are more common as we can
    have the following scenarios during the rotation looping:

    case1 only, case1+1, case2+3, case1+2+3, case3 only, etc.

This patch, therefore, adds an unlikely() optimization to this
conditional.  When profiling with CONFIG_PROFILE_ANNOTATED_BRANCHES, a
kernel build shows that the incorrect rate is less than 15%, and for
workloads that involve insert mostly trees overtime tend to have less
than 2% incorrect rate.

Link: http://lkml.kernel.org/r/20170719014603.19029-3-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Davidlohr Bueso
cd9e61ed1e rbtree: cache leftmost node internally
Patch series "rbtree: Cache leftmost node internally", v4.

A series to extending rbtrees to internally cache the leftmost node such
that we can have fast overlap check optimization for all interval tree
users[1].  The benefits of this series are that:

(i)   Unify users that do internal leftmost node caching.
(ii)  Optimize all interval tree users.
(iii) Convert at least two new users (epoll and procfs) to the new interface.

This patch (of 16):

Red-black tree semantics imply that nodes with smaller or greater (or
equal for duplicates) keys always be to the left and right,
respectively.  For the kernel this is extremely evident when considering
our rb_first() semantics.  Enabling lookups for the smallest node in the
tree in O(1) can save a good chunk of cycles in not having to walk down
the tree each time.  To this end there are a few core users that
explicitly do this, such as the scheduler and rtmutexes.  There is also
the desire for interval trees to have this optimization allowing faster
overlap checking.

This patch introduces a new 'struct rb_root_cached' which is just the
root with a cached pointer to the leftmost node.  The reason why the
regular rb_root was not extended instead of adding a new structure was
that this allows the user to have the choice between memory footprint
and actual tree performance.  The new wrappers on top of the regular
rb_root calls are:

 - rb_first_cached(cached_root) -- which is a fast replacement
     for rb_first.

 - rb_insert_color_cached(node, cached_root, new)

 - rb_erase_cached(node, cached_root)

In addition, augmented cached interfaces are also added for basic
insertion and deletion operations; which becomes important for the
interval tree changes.

With the exception of the inserts, which adds a bool for updating the
new leftmost, the interfaces are kept the same.  To this end, porting rb
users to the cached version becomes really trivial, and keeping current
rbtree semantics for users that don't care about the optimization
requires zero overhead.

Link: http://lkml.kernel.org/r/20170719014603.19029-2-dave@stgolabs.net
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00
Matthias Kaehlcke
c32ee3d9ab bitops: avoid integer overflow in GENMASK(_ULL)
GENMASK(_ULL) performs a left-shift of ~0UL(L), which technically
results in an integer overflow.  clang raises a warning if the overflow
occurs in a preprocessor expression.  Clear the low-order bits through a
substraction instead of the left-shift to avoid the overflow.

(akpm: no change in .text size in my testing)

Link: http://lkml.kernel.org/r/20170803212020.24939-1-mka@chromium.org
Signed-off-by: Matthias Kaehlcke <mka@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08 18:26:48 -07:00