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2017-09-08kmod: split out umh code into its own fileLuis R. Rodriguez4-559/+577
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>
2017-09-08test_kmod: flip INT checks to be consistentDan Carpenter1-1/+1
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>
2017-09-08test_kmod: remove paranoid UINT_MAX check on uint range processingDan Carpenter1-1/+1
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>
2017-09-08vfat: deduplicate hex2bin()OGAWA Hirofumi1-23/+12
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>
2017-09-08autofs: use unsigned int/long instead of uint/ulong for ioctl argsTomohiro Kusumi1-4/+6
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>
2017-09-08autofs: drop wrong commentTomohiro Kusumi1-5/+0
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>
2017-09-08autofs: use AUTOFS_DEV_IOCTL_SIZETomohiro Kusumi1-7/+7
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>
2017-09-08autofs: non functional header inclusion cleanupTomohiro Kusumi1-11/+11
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>
2017-09-08autofs: remove unused AUTOFS_IOC_EXPIRE_DIRECT/INDIRECTTomohiro Kusumi1-2/+0
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>
2017-09-08autofs: make dev ioctl version and ismountpoint user accessibleIan Kent2-5/+9
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>
2017-09-08autofs: make disc device user accessibleIan Kent1-1/+2
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>
2017-09-08autofs: fix AT_NO_AUTOMOUNT not being honoredIan Kent2-5/+13
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: deccf497d804a4c5fca ("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>
2017-09-08init/main.c: extract early boot entropy from the passed cmdlineDaniel Micay1-0/+2
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>
2017-09-08init: move stack canary initialization after setup_archLaura Abbott1-6/+5
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>
2017-09-08binfmt_flat: delete two error messages for a failed memory allocation in ↵Markus Elfring1-5/+3
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>
2017-09-08checkpatch: add 6 missing types to --list-typesJean Delvare1-1/+2
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: 3beb42eced39 ("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>
2017-09-08checkpatch: rename variables to avoid confusionJean Delvare1-16/+16
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>
2017-09-08checkpatch: fix typo in commentJean Delvare1-1/+1
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>
2017-09-08checkpatch: add --strict check for ifs with unnecessary parenthesesJoe Perches1-0/+24
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>
2017-09-08lib/oid_registry.c: X.509: fix the buffer overflow in the utility function ↵Takashi Iwai1-2/+2
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>
2017-09-08radix-tree: must check __radix_tree_preload() return valueEric Dumazet1-4/+5
__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: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree") Fixes: 7ad3d4d85c7a ("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>
2017-09-08lib/cmdline.c: remove meaningless commentBaoquan He1-1/+0
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>
2017-09-08lib/string.c: check for kmalloc() failureDan Carpenter1-3/+15
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>
2017-09-08lib/rhashtable: fix comment on locks_mul default valueDavidlohr Bueso1-1/+1
As of commit 4cf0b354d92 ("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>
2017-09-08bitmap: introduce BITMAP_FROM_U64()Yury Norov2-15/+64
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>
2017-09-08lib/test_bitmap.c: add test for bitmap_parselist()Yury Norov1-0/+74
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>
2017-09-08lib/bitmap.c: make bitmap_parselist() thread-safe and much fasterYury Norov1-12/+6
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>
2017-09-08lib: add test module for CONFIG_DEBUG_VIRTUALFlorian Fainelli3-0/+61
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>
2017-09-08lib/hexdump.c: return -EINVAL in case of error in hex2bin()Andy Shevchenko1-2/+3
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>
2017-09-08block/cfq: cache rightmost rb_nodeDavidlohr Bueso1-5/+14
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>
2017-09-08mem/memcg: cache rightmost nodeDavidlohr Bueso1-5/+18
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>
2017-09-08fs/epoll: use faster rb_first_cached()Davidlohr Bueso1-14/+16
... 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>
2017-09-08procfs: use faster rb_first_cached()Davidlohr Bueso4-15/+17
... 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>
2017-09-08lib/interval-tree: correct comment wrt generic flavorDavidlohr Bueso1-1/+1
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>
2017-09-08lib/interval_tree: fast overlap detectionDavidlohr Bueso33-105/+145
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>
2017-09-08block/cfq: replace cfq_rb_root leftmost cachingDavidlohr Bueso1-50/+20
... 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>
2017-09-08locking/rtmutex: replace top-waiter and pi_waiters leftmost cachingDavidlohr Bueso7-44/+27
... 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>
2017-09-08sched/deadline: replace earliest dl and rq leftmost cachingDavidlohr Bueso2-35/+21
... 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>
2017-09-08sched/fair: replace cfs_rq->rb_leftmostDavidlohr Bueso3-29/+15
... 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>
2017-09-08lib/rbtree_test.c: support rb_root_cachedDavidlohr Bueso1-19/+137
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>
2017-09-08lib/rbtree_test.c: add (inorder) traversal testDavidlohr Bueso1-2/+23
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>
2017-09-08lib/rbtree_test.c: make input module parametersDavidlohr Bueso1-21/+34
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>
2017-09-08rbtree: add some additional comments for rebalancing casesDavidlohr Bueso1-3/+5
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>
2017-09-08rbtree: optimize root-check during rebalancing loopDavidlohr Bueso1-7/+16
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>
2017-09-08rbtree: cache leftmost node internallyDavidlohr Bueso4-8/+113
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>
2017-09-08bitops: avoid integer overflow in GENMASK(_ULL)Matthias Kaehlcke1-2/+3
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>
2017-09-08include: warn for inconsistent endian config definitionBabu Moger2-0/+8
We have seen some generic code use config parameter CONFIG_CPU_BIG_ENDIAN to decide the endianness. Here are the few examples. include/asm-generic/qrwlock.h drivers/of/base.c drivers/of/fdt.c drivers/tty/serial/earlycon.c drivers/tty/serial/serial_core.c Display warning if CPU_BIG_ENDIAN is not defined on big endian architecture and also warn if it defined on little endian architectures. Here is our original discussion https://lkml.org/lkml/2017/5/24/620 Link: http://lkml.kernel.org/r/1499358861-179979-4-git-send-email-babu.moger@oracle.com Signed-off-by: Babu Moger <babu.moger@oracle.com> Suggested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David S. Miller <davem@davemloft.net> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jonas Bonn <jonas@southpole.se> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Michal Simek <monstr@monstr.eu> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08arch/microblaze: add choice for endianness and update MakefileBabu Moger2-0/+18
microblaze architectures can be configured for either little or big endian formats. Add a choice option for the user to select the correct endian format(default to big endian). Also update the Makefile so toolchain can compile for the format it is configured for. Link: http://lkml.kernel.org/r/1499358861-179979-3-git-send-email-babu.moger@oracle.com Signed-off-by: Babu Moger <babu.moger@oracle.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Michal Simek <monstr@monstr.eu> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: David S. Miller <davem@davemloft.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Helge Deller <deller@gmx.de> Cc: Ingo Molnar <mingo@elte.hu> Cc: Jonas Bonn <jonas@southpole.se> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stafford Horne <shorne@gmail.com> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08arch: define CPU_BIG_ENDIAN for all fixed big endian archsBabu Moger6-0/+18
Patch series "Define CPU_BIG_ENDIAN or warn for inconsistencies", v3. While working on enabling queued rwlock on SPARC, found this following code in include/asm-generic/qrwlock.h which uses CONFIG_CPU_BIG_ENDIAN to clear a byte. static inline u8 *__qrwlock_write_byte(struct qrwlock *lock) { return (u8 *)lock + 3 * IS_BUILTIN(CONFIG_CPU_BIG_ENDIAN); } Problem is many of the fixed big endian architectures don't define CPU_BIG_ENDIAN and clears the wrong byte. Define CPU_BIG_ENDIAN for all the fixed big endian architecture to fix it. Also found few more references of this config parameter in drivers/of/base.c drivers/of/fdt.c drivers/tty/serial/earlycon.c drivers/tty/serial/serial_core.c Be aware that this may cause regressions if someone has worked-around problems in the above code already. Remove the work-around. Here is our original discussion https://lkml.org/lkml/2017/5/24/620 Link: http://lkml.kernel.org/r/1499358861-179979-2-git-send-email-babu.moger@oracle.com Signed-off-by: Babu Moger <babu.moger@oracle.com> Suggested-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Stafford Horne <shorne@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Jonas Bonn <jonas@southpole.se> Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Simek <monstr@monstr.eu> Cc: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-08treewide: make "nr_cpu_ids" unsignedAlexey Dobriyan17-21/+21
First, number of CPUs can't be negative number. Second, different signnnedness leads to suboptimal code in the following cases: 1) kmalloc(nr_cpu_ids * sizeof(X)); "int" has to be sign extended to size_t. 2) while (loff_t *pos < nr_cpu_ids) MOVSXD is 1 byte longed than the same MOV. Other cases exist as well. Basically compiler is told that nr_cpu_ids can't be negative which can't be deduced if it is "int". Code savings on allyesconfig kernel: -3KB add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370) function old new delta coretemp_cpu_online 450 512 +62 rcu_init_one 1234 1272 +38 pci_device_probe 374 399 +25 ... pgdat_reclaimable_pages 628 556 -72 select_fallback_rq 446 369 -77 task_numa_find_cpu 1923 1807 -116 Link: http://lkml.kernel.org/r/20170819114959.GA30580@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>
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