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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull debugfs patches from Al Viro:
"debugfs patches, mostly to make it possible for something like tracefs
to be transparently automounted on given directory in debugfs.
New primitive in there is debugfs_create_automount(name, parent, func,
arg), which creates a directory and makes its ->d_automount() return
func(arg). Another missing primitive was debugfs_create_file_size() -
open-coded in quite a few places. Dave's patch adds it and converts
the open-code instances to calling it"
* 'debugfs_automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
debugfs: Provide a file creation function that also takes an initial size
new primitive: debugfs_create_automount()
debugfs: split end_creating() into success and failure cases
debugfs: take mode-dependent parts of debugfs_get_inode() into callers
fold debugfs_mknod() into callers
fold debugfs_create() into caller
fold debugfs_mkdir() into caller
debugfs_mknod(): get rid useless arguments
fold debugfs_link() into caller
debugfs: kill __create_file()
debugfs: split the beginning and the end of __create_file() off
debugfs_{mkdir,create,link}(): get rid of redundant argument
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc VFS updates from Al Viro:
"This cycle a lot of stuff sits on topical branches, so I'll be sending
more or less one pull request per branch.
This is the first pile; more to follow in a few. In this one are
several misc commits from early in the cycle (before I went for
separate branches), plus the rework of mntput/dput ordering on umount,
switching to use of fs_pin instead of convoluted games in
namespace_unlock()"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
switch the IO-triggering parts of umount to fs_pin
new fs_pin killing logics
allow attaching fs_pin to a group not associated with some superblock
get rid of the second argument of acct_kill()
take count and rcu_head out of fs_pin
dcache: let the dentry count go down to zero without taking d_lock
pull bumping refcount into ->kill()
kill pin_put()
mode_t whack-a-mole: chelsio
file->f_path.dentry is pinned down for as long as the file is open...
get rid of lustre_dump_dentry()
gut proc_register() a bit
kill d_validate()
ncpfs: get rid of d_validate() nonsense
selinuxfs: don't open-code d_genocide()
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Merge yet more updates from Andrew Morton:
- a pile of minor fs fixes and cleanups
- kexec updates
- random misc fixes in various places: vmcore, rbtree, eventfd, ipc, seccomp.
- a series of python-based kgdb helper scripts
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO
samples/seccomp: improve label helper
ipc,sem: use current->state helpers
scripts/gdb: disable pagination while printing from breakpoint handler
scripts/gdb: define maintainer
scripts/gdb: convert CpuList to generator function
scripts/gdb: convert ModuleList to generator function
scripts/gdb: use a generator instead of iterator for task list
scripts/gdb: ignore byte-compiled python files
scripts/gdb: port to python3 / gdb7.7
scripts/gdb: add basic documentation
scripts/gdb: add lx-lsmod command
scripts/gdb: add class to iterate over CPU masks
scripts/gdb: add lx_current convenience function
scripts/gdb: add internal helper and convenience function for per-cpu lookup
scripts/gdb: add get_gdbserver_type helper
scripts/gdb: add internal helper and convenience function to retrieve thread_info
scripts/gdb: add is_target_arch helper
scripts/gdb: add helper and convenience function to look up tasks
scripts/gdb: add task iteration class
...
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Signed-off-by: John de la Garza <john@jjdev.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add a new kexec preprocessor macro IND_FLAGS, which is the bitwise OR of
all the possible kexec IND_ kimage_entry indirection flags. Having this
macro allows for simplified code in the prosessing of the kexec
kimage_entry items. Also, remove the local powerpc definition and use the
generic one.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Maximilian Attems <max@stro.at>
Cc: Michal Marek <mmarek@suse.cz>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Define new kexec preprocessor macros IND_*_BIT that define the bit
position of the kimage entry flags. Change the existing IND_* flag macros
to be defined as bit shifts of the corresponding IND_*_BIT macros. Also
wrap all C language code in kexec.h with #if !defined(__ASSEMBLY__) so
assembly files can include kexec.h to get the IND_* and IND_*_BIT macros.
Some CPU instruction sets have tests for bit position which are convenient
in implementing routines that operate on the kimage entry list. The
addition of these bit position macros in a common location will avoid
duplicate definitions and the chance that changes to the IND_* flags will
not be propagated to assembly files.
Signed-off-by: Geoff Levand <geoff@infradead.org>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Maximilian Attems <max@stro.at>
Cc: Michal Marek <mmarek@suse.cz>
Cc: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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struct kimage has a member destination which is used to store the real
destination address of each page when load segment from user space buffer
to kernel. But we never retrieve the value stored in kimage->destination,
so this member variable in kimage and its assignment operation are
redundent code.
I guess for_each_kimage_entry just does the work that kimage->destination
is expected to do.
So in this patch just make a cleanup to remove it.
Signed-off-by: Baoquan He <bhe@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull suspend-to-idle updates from Rafael Wysocki:
"Suspend-to-idle timer quiescing support for v3.20-rc1
Until now suspend-to-idle has not been able to save much more energy
than runtime PM because of timer interrupts that periodically bring
CPUs out of idle while they are waiting for a wakeup interrupt. Of
course, the timer interrupts are not wakeup ones, so the handling of
them can be deferred until a real wakeup interrupt happens, but at the
same time we don't want to mass-expire timers at that point.
The solution is to suspend the entire timekeeping when the last CPU is
entering an idle state and resume it when the first CPU goes out of
idle. That has to be done with care, though, so as to avoid accessing
suspended clocksources etc. end we need extra support from idle
drivers for that.
This series of commits adds support for quiescing timers during
suspend-to-idle and adds the requisite callbacks to intel_idle and the
ACPI cpuidle driver"
* tag 'suspend-to-idle-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
ACPI / idle: Implement ->enter_freeze callback routine
intel_idle: Add ->enter_freeze callbacks
PM / sleep: Make it possible to quiesce timers during suspend-to-idle
timekeeping: Make it safe to use the fast timekeeper while suspended
timekeeping: Pass readout base to update_fast_timekeeper()
PM / sleep: Re-implement suspend-to-idle handling
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git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull ARM SoC driver updates from Olof Johansson:
"These are changes for drivers that are intimately tied to some SoC and
for some reason could not get merged through the respective subsystem
maintainer tree.
This time around, much of this is for at91, with the bulk of it being
syscon and udc drivers.
Also, there's:
- coupled cpuidle support for Samsung Exynos4210
- Renesas 73A0 common-clk work
- of/platform changes to tear down DMA mappings on device destruction
- a few updates to the TI Keystone knav code"
* tag 'drivers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (26 commits)
cpuidle: exynos: add coupled cpuidle support for exynos4210
ARM: EXYNOS: apply S5P_CENTRAL_SEQ_OPTION fix only when necessary
soc: ti: knav_qmss_queue: change knav_range_setup_acc_irq to static
soc: ti: knav_qmss_queue: makefile tweak to build as dynamic module
pcmcia: at91_cf: depend on !ARCH_MULTIPLATFORM
soc: ti: knav_qmss_queue: export API calls for use by user driver
of/platform: teardown DMA mappings on device destruction
usb: gadget: at91_udc: Allocate udc instance
usb: gadget: at91_udc: Update DT binding documentation
usb: gadget: at91_udc: Rework for multi-platform kernel support
usb: gadget: at91_udc: Simplify probe and remove functions
usb: gadget: at91_udc: Remove non-DT handling code
usb: gadget: at91_udc: Document DT clocks and clock-names property
usb: gadget: at91_udc: Drop uclk clock
usb: gadget: at91_udc: Fix clock names
mfd: syscon: Add Atmel SMC binding doc
mfd: syscon: Add atmel-smc registers definition
mfd: syscon: Add Atmel Matrix bus DT binding documentation
mfd: syscon: Add atmel-matrix registers definition
clk: shmobile: fix sparse NULL pointer warning
...
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Provide a file creation function that also takes an initial size so that the
caller doesn't have to set i_size, thus meaning that we don't have to call
deal with ->d_inode in the callers.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Merge fifth set of updates from Andrew Morton:
- A few things which were awaiting merges from linux-next:
- rtc
- ocfs2
- misc others
- Willy's "dax" feature: direct fs access to memory (mainly NV-DIMMs)
which isn't backed by pageframes.
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (37 commits)
rtc: add driver for DS1685 family of real time clocks
MAINTAINERS: add entry for Maxim PMICs on Samsung boards
lib/Kconfig: use bool instead of boolean
powerpc: drop _PAGE_FILE and pte_file()-related helpers
ocfs2: set append dio as a ro compat feature
ocfs2: wait for orphan recovery first once append O_DIRECT write crash
ocfs2: complete the rest request through buffer io
ocfs2: do not fallback to buffer I/O write if appending
ocfs2: allocate blocks in ocfs2_direct_IO_get_blocks
ocfs2: implement ocfs2_direct_IO_write
ocfs2: add orphan recovery types in ocfs2_recover_orphans
ocfs2: add functions to add and remove inode in orphan dir
ocfs2: prepare some interfaces used in append direct io
MAINTAINERS: fix spelling mistake & remove trailing WS
dax: does not work correctly with virtual aliasing caches
brd: rename XIP to DAX
ext4: add DAX functionality
dax: add dax_zero_page_range
ext2: get rid of most mentions of XIP in ext2
ext2: remove ext2_aops_xip
...
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This adds a driver for the Dallas/Maxim DS1685-family of RTC chips. It
supports the DS1685/DS1687, DS1688/DS1691, DS1689/DS1693, DS17285/DS17287,
DS17485/DS17487, and DS17885/DS17887 RTC chips. These chips are commonly
found in SGI O2 and SGI Octane systems. It was originally derived from a
driver patch submitted by Matthias Fuchs many years ago for use in
EPPC-405-UC modules, which also used these RTCs. In addition to the
time-keeping functions, this RTC also handles the shutdown mechanism of
the O2 and Octane and acts as a partial NVRAM for the boot PROMS in these
systems.
Verified on both an SGI O2 and an SGI Octane.
Signed-off-by: Joshua Kinard <kumba@gentoo.org>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This new function allows us to support hole-punch for DAX files by zeroing
a partial page, as opposed to the dax_truncate_page() function which can
only truncate to the end of the page. Reimplement dax_truncate_page() to
call dax_zero_page_range().
[ross.zwisler@linux.intel.com: ported to 3.13-rc2]
[akpm@linux-foundation.org: fix typos in comments]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The fewer Kconfig options we have the better. Use the generic
CONFIG_FS_DAX to enable XIP support in ext2 as well as in the core.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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All callers of get_xip_mem() are now gone. Remove checks for it,
initialisers of it, documentation of it and the only implementation of it.
Also remove mm/filemap_xip.c as it is now empty. Also remove
documentation of the long-gone get_xip_page().
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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It takes a get_block parameter just like nobh_truncate_page() and
block_truncate_page()
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Instead of calling aops->get_xip_mem from the fault handler, the
filesystem passes a get_block_t that is used to find the appropriate
blocks.
This requires that all architectures implement copy_user_page(). At the
time of writing, mips and arm do not. Patches exist and are in progress.
[akpm@linux-foundation.org: remap_file_pages went away]
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is practically generic code; other filesystems will want to call it
from other places, but there's nothing ext2-specific about it.
Make it a little more generic by allowing it to take a count of the number
of bytes to zero rather than fixing it to a single page. Thanks to Dave
Hansen for suggesting that I need to call cond_resched() if zeroing more
than one page.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Use the generic AIO infrastructure instead of custom read and write
methods. In addition to giving us support for AIO, this adds the missing
locking between read() and truncate().
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Use an inode flag to tag inodes which should avoid using the page cache.
Convert ext2 to use it instead of mapping_is_xip(). Prevent I/Os to files
tagged with the DAX flag from falling back to buffered I/O.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Currently COW of an XIP file is done by first bringing in a read-only
mapping, then retrying the fault and copying the page. It is much more
efficient to tell the fault handler that a COW is being attempted (by
passing in the pre-allocated page in the vm_fault structure), and allow
the handler to perform the COW operation itself.
The handler cannot insert the page itself if there is already a read-only
mapping at that address, so allow the handler to return VM_FAULT_LOCKED
and set the fault_page to be NULL. This indicates to the MM code that the
i_mmap_lock is held instead of the page lock.
Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andreas Dilger <andreas.dilger@intel.com>
Cc: Boaz Harrosh <boaz@plexistor.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Pull drm updates from Dave Airlie:
"This is the main drm pull, it has a shared branch with some alsa
crossover but everything should be acked by relevant people.
New drivers:
- ATMEL HLCDC driver
- designware HDMI core support (used in multiple SoCs).
core:
- lots more atomic modesetting work, properties and atomic ioctl
(hidden under option)
- bridge rework allows support for Samsung exynos chromebooks to
work finally.
- some more panels supported
i915:
- atomic plane update support
- DSI uses shared DSI infrastructure
- Skylake basic support is all merged now
- component framework used for i915/snd-hda interactions
- write-combine cpu memory mappings
- engine init code refactored
- full ppgtt enabled where execlists are enabled.
- cherryview rps/gpu turbo and pipe CRC support.
radeon:
- indirect draw support for evergreen/cayman
- SMC and manual fan control for SI/CI
- Displayport audio support
amdkfd:
- SDMA usermode queue support
- replace suballocator usage with more suitable one
- rework for allowing interfacing to more than radeon
nouveau:
- major renaming in prep for later splitting work
- merge arm platform driver into nouveau
- GK20A reclocking support
msm:
- conversion to atomic modesetting
- YUV support for mdp4/5
- eDP support
- hw cursor for mdp5
tegra:
- conversion to atomic modesetting
- better suspend/resume support for child devices
rcar-du:
- interlaced support
imx:
- move to using dw_hdmi shared support
- mode_fixup support
sti:
- DVO support
- HDMI infoframe support
exynos:
- refactoring and cleanup, removed lots of internal unnecessary
abstraction
- exynos7 DECON display controller support
Along with the usual bunch of fixes, cleanups etc"
* 'drm-next' of git://people.freedesktop.org/~airlied/linux: (724 commits)
drm/radeon: fix voltage setup on hawaii
drm/radeon/dp: Set EDP_CONFIGURATION_SET for bridge chips if necessary
drm/radeon: only enable kv/kb dpm interrupts once v3
drm/radeon: workaround for CP HW bug on CIK
drm/radeon: Don't try to enable write-combining without PAT
drm/radeon: use 0-255 rather than 0-100 for pwm fan range
drm/i915: Clamp efficient frequency to valid range
drm/i915: Really ignore long HPD pulses on eDP
drm/exynos: Add DECON driver
drm/i915: Correct the base value while updating LP_OUTPUT_HOLD in MIPI_PORT_CTRL
drm/i915: Insert a command barrier on BLT/BSD cache flushes
drm/i915: Drop vblank wait from intel_dp_link_down
drm/exynos: fix NULL pointer reference
drm/exynos: remove exynos_plane_dpms
drm/exynos: remove mode property of exynos crtc
drm/exynos: Remove exynos_plane_dpms() call with no effect
drm/i915: Squelch overzealous uncore reset WARN_ON
drm/i915: Take runtime pm reference on hangcheck_info
drm/i915: Correct the IOSF Dev_FN field for IOSF transfers
drm/exynos: fix DMA_ATTR_NO_KERNEL_MAPPING usage
...
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|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irqchip updates from Ingo Molnar:
"Various irqchip driver updates, plus a genirq core update that allows
the initial spreading of irqs amonst CPUs without having to do it from
user-space"
* 'irq-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
genirq: Fix null pointer reference in irq_set_affinity_hint()
irqchip: gic: Allow interrupt level to be set for PPIs
irqchip: mips-gic: Handle pending interrupts once in __gic_irq_dispatch()
irqchip: Conexant CX92755 interrupts controller driver
irqchip: Devicetree: document Conexant Digicolor irq binding
irqchip: omap-intc: Remove unused legacy interface for omap2
irqchip: omap-intc: Fix support for dm814 and dm816
irqchip: mtk-sysirq: Get irq number from register resource size
irqchip: renesas-intc-irqpin: r8a7779 IRLM setup support
genirq: Set initial affinity in irq_set_affinity_hint()
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|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 perf updates from Ingo Molnar:
"This series tightens up RDPMC permissions: currently even highly
sandboxed x86 execution environments (such as seccomp) have permission
to execute RDPMC, which may leak various perf events / PMU state such
as timing information and other CPU execution details.
This 'all is allowed' RDPMC mode is still preserved as the
(non-default) /sys/devices/cpu/rdpmc=2 setting. The new default is
that RDPMC access is only allowed if a perf event is mmap-ed (which is
needed to correctly interpret RDPMC counter values in any case).
As a side effect of these changes CR4 handling is cleaned up in the
x86 code and a shadow copy of the CR4 value is added.
The extra CR4 manipulation adds ~ <50ns to the context switch cost
between rdpmc-capable and rdpmc-non-capable mms"
* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks
perf/x86: Only allow rdpmc if a perf_event is mapped
perf: Pass the event to arch_perf_update_userpage()
perf: Add pmu callbacks to track event mapping and unmapping
x86: Add a comment clarifying LDT context switching
x86: Store a per-cpu shadow copy of CR4
x86: Clean up cr4 manipulation
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver patches from Greg KH:
"Here's the big tty/serial driver update for 3.20-rc1. Nothing huge
here, just lots of driver updates and some core tty layer fixes as
well. All have been in linux-next with no reported issues"
* tag 'tty-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (119 commits)
serial: 8250: Fix UART_BUG_TXEN workaround
serial: driver for ETRAX FS UART
tty: remove unused variable sprop
serial: of-serial: fetch line number from DT
serial: samsung: earlycon support depends on CONFIG_SERIAL_SAMSUNG_CONSOLE
tty/serial: serial8250_set_divisor() can be static
tty/serial: Add Spreadtrum sc9836-uart driver support
Documentation: DT: Add bindings for Spreadtrum SoC Platform
serial: samsung: remove redundant interrupt enabling
tty: Remove external interface for tty_set_termios()
serial: omap: Fix RTS handling
serial: 8250_omap: Use UPSTAT_AUTORTS for RTS handling
serial: core: Rework hw-assisted flow control support
tty/serial: 8250_early: Add support for PXA UARTs
tty/serial: of_serial: add support for PXA/MMP uarts
tty/serial: of_serial: add DT alias ID handling
serial: 8250: Prevent concurrent updates to shadow registers
serial: 8250: Use canary to restart console after suspend
serial: 8250: Refactor XR17V35X divisor calculation
serial: 8250: Refactor divisor programming
...
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging drivers patches from Greg KH:
"Here's the big staging driver tree update for 3.20-rc1.
Lots of little things in here, adding up to lots of overall cleanups.
The IIO driver updates are also in here as they cross the staging tree
boundry a lot. I2O has moved into staging as well, as a plan to drop
it from the tree eventually as that's a dead subsystem.
All of this has been in linux-next with no reported issues for a
while"
* tag 'staging-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (740 commits)
staging: lustre: lustre: libcfs: define symbols as static
staging: rtl8712: Do coding style cleanup
staging: lustre: make obd_updatemax_lock static
staging: rtl8188eu: core: switch with redundant cases
staging: rtl8188eu: odm: conditional setting with no effect
staging: rtl8188eu: odm: condition with no effect
staging: ft1000: fix braces warning
staging: sm7xxfb: fix remaining CamelCase
staging: sm7xxfb: fix CamelCase
staging: rtl8723au: multiple condition with no effect - if identical to else
staging: sm7xxfb: make smtc_scr_info static
staging/lustre/mdc: Initialize req in mdc_enqueue for !it case
staging/lustre/clio: Do not allow group locks with gid 0
staging/lustre/llite: don't add to page cache upon failure
staging/lustre/llite: Add exception entry check after radix_tree
staging/lustre/libcfs: protect kkuc_groups from write access
staging/lustre/fld: refer to MDT0 for fld lookup in some cases
staging/lustre/llite: Solve a race to access lli_has_smd in read case
staging/lustre/ptlrpc: hold rq_lock when modify rq_flags
staging/lustre/lnet: portal spreading rotor should be unsigned
...
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core patches from Greg KH:
"Really tiny set of patches for this kernel. Nothing major, all
described in the shortlog and have been in linux-next for a while"
* tag 'driver-core-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
sysfs: fix warning when creating a sysfs group without attributes
firmware_loader: handle timeout via wait_for_completion_interruptible_timeout()
firmware_loader: abort request if wait_for_completion is interrupted
firmware: Correct function name in comment
device: Change dev_<level> logging functions to return void
device: Fix dev_dbg_once macro
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char / misc patches from Greg KH:
"Here's the big char/misc driver update for 3.20-rc1.
Lots of little things in here, all described in the changelog.
Nothing major or unusual, except maybe the binder selinux stuff, which
was all acked by the proper selinux people and they thought it best to
come through this tree.
All of this has been in linux-next with no reported issues for a while"
* tag 'char-misc-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (90 commits)
coresight: fix function etm_writel_cp14() parameter order
coresight-etm: remove check for unknown Kconfig macro
coresight: fixing CPU hwid lookup in device tree
coresight: remove the unnecessary function coresight_is_bit_set()
coresight: fix the debug AMBA bus name
coresight: remove the extra spaces
coresight: fix the link between orphan connection and newly added device
coresight: remove the unnecessary replicator property
coresight: fix the replicator subtype value
pdfdocs: Fix 'make pdfdocs' failure for 'uio-howto.tmpl'
mcb: Fix error path of mcb_pci_probe
virtio/console: verify device has config space
ti-st: clean up data types (fix harmless memory corruption)
mei: me: release hw from reset only during the reset flow
mei: mask interrupt set bit on clean reset bit
extcon: max77693: Constify struct regmap_config
extcon: adc-jack: Release IIO channel on driver remove
extcon: Remove duplicated include from extcon-class.c
Drivers: hv: vmbus: hv_process_timer_expiration() can be static
Drivers: hv: vmbus: serialize Offer and Rescind offer
...
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The efficiency of suspend-to-idle depends on being able to keep CPUs
in the deepest available idle states for as much time as possible.
Ideally, they should only be brought out of idle by system wakeup
interrupts.
However, timer interrupts occurring periodically prevent that from
happening and it is not practical to chase all of the "misbehaving"
timers in a whack-a-mole fashion. A much more effective approach is
to suspend the local ticks for all CPUs and the entire timekeeping
along the lines of what is done during full suspend, which also
helps to keep suspend-to-idle and full suspend reasonably similar.
The idea is to suspend the local tick on each CPU executing
cpuidle_enter_freeze() and to make the last of them suspend the
entire timekeeping. That should prevent timer interrupts from
triggering until an IO interrupt wakes up one of the CPUs. It
needs to be done with interrupts disabled on all of the CPUs,
though, because otherwise the suspended clocksource might be
accessed by an interrupt handler which might lead to fatal
consequences.
Unfortunately, the existing ->enter callbacks provided by cpuidle
drivers generally cannot be used for implementing that, because some
of them re-enable interrupts temporarily and some idle entry methods
cause interrupts to be re-enabled automatically on exit. Also some
of these callbacks manipulate local clock event devices of the CPUs
which really shouldn't be done after suspending their ticks.
To overcome that difficulty, introduce a new cpuidle state callback,
->enter_freeze, that will be guaranteed (1) to keep interrupts
disabled all the time (and return with interrupts disabled) and (2)
not to touch the CPU timer devices. Modify cpuidle_enter_freeze() to
look for the deepest available idle state with ->enter_freeze present
and to make the CPU execute that callback with suspended tick (and the
last of the online CPUs to execute it with suspended timekeeping).
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB patches from Greg KH:
"Here's the big pull request for the USB driver tree for 3.20-rc1.
Nothing major happening here, just lots of gadget driver updates, new
device ids, and a bunch of cleanups.
All of these have been in linux-next for a while with no reported
issues"
* tag 'usb-3.20-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (299 commits)
usb: musb: fix device hotplug behind hub
usb: dwc2: Fix a bug in reading the endpoint directions from reg.
staging: emxx_udc: fix the build error
usb: Retry port status check on resume to work around RH bugs
Revert "usb: Reset USB-3 devices on USB-3 link bounce"
uhci-hub: use HUB_CHAR_*
usb: kconfig: replace PPC_OF with PPC
ehci-pci: disable for Intel MID platforms (update)
usb: gadget: Kconfig: use bool instead of boolean
usb: musb: blackfin: remove incorrect __exit_p()
USB: fix use-after-free bug in usb_hcd_unlink_urb()
ehci-pci: disable for Intel MID platforms
usb: host: pci_quirks: joing string literals
USB: add flag for HCDs that can't receive wakeup requests (isp1760-hcd)
USB: usbfs: allow URBs to be reaped after disconnection
cdc-acm: kill unnecessary messages
cdc-acm: add sanity checks
usb: phy: phy-generic: Fix USB PHY gpio reset
usb: dwc2: fix USB core dependencies
usb: renesas_usbhs: fix NULL pointer dereference in dma_release_channel()
...
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Pull UBI and UBIFS updates from Richard Weinberger:
- cleanups and bug fixes all over UBI and UBIFS
- block-mq support for UBI Block
- UBI volumes can now be renamed while they are in use
- security.* XATTR support for UBIFS
- a maintainer update
* 'for-linus-v3.20' of git://git.infradead.org/linux-ubifs:
UBI: block: Fix checking for NULL instead of IS_ERR()
UBI: block: Continue creating ubiblocks after an initialization error
UBIFS: return -EINVAL if log head is empty
UBI: Block: Explain usage of blk_rq_map_sg()
UBI: fix soft lockup in ubi_check_volume()
UBI: Fastmap: Care about the protection queue
UBIFS: add a couple of extra asserts
UBI: do propagate positive error codes up
UBI: clean-up printing helpers
UBI: extend UBI layer debug/messaging capabilities - cosmetics
UBIFS: add ubifs_err() to print error reason
UBIFS: Add security.* XATTR support for the UBIFS
UBIFS: Add xattr support for symlinks
UBI: Block: Add blk-mq support
UBI: Add initial support for scatter gather
UBI: rename_volumes: Use UBI_METAONLY
UBI: Implement UBI_METAONLY
Add myself as UBI co-maintainer
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This field is unused and uninitialized since commit 9a11b49a8056
("[PATCH] lockdep: better lock debugging")
Signed-off-by: Adrien Schildknecht <adrien+dev@schischi.me>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux
Pull ACCESS_ONCE() rule tightening from Christian Borntraeger:
"Tighten rules for ACCESS_ONCE
This series tightens the rules for ACCESS_ONCE to only work on scalar
types. It also contains the necessary fixups as indicated by build
bots of linux-next. Now everything is in place to prevent new
non-scalar users of ACCESS_ONCE and we can continue to convert code to
READ_ONCE/WRITE_ONCE"
* tag 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/borntraeger/linux:
kernel: Fix sparse warning for ACCESS_ONCE
next: sh: Fix compile error
kernel: tighten rules for ACCESS ONCE
mm/gup: Replace ACCESS_ONCE with READ_ONCE
x86/spinlock: Leftover conversion ACCESS_ONCE->READ_ONCE
x86/xen/p2m: Replace ACCESS_ONCE with READ_ONCE
ppc/hugetlbfs: Replace ACCESS_ONCE with READ_ONCE
ppc/kvm: Replace ACCESS_ONCE with READ_ONCE
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Pull crypto update from Herbert Xu:
"Here is the crypto update for 3.20:
- Added 192/256-bit key support to aesni GCM.
- Added MIPS OCTEON MD5 support.
- Fixed hwrng starvation and race conditions.
- Added note that memzero_explicit is not a subsitute for memset.
- Added user-space interface for crypto_rng.
- Misc fixes"
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (71 commits)
crypto: tcrypt - do not allocate iv on stack for aead speed tests
crypto: testmgr - limit IV copy length in aead tests
crypto: tcrypt - fix buflen reminder calculation
crypto: testmgr - mark rfc4106(gcm(aes)) as fips_allowed
crypto: caam - fix resource clean-up on error path for caam_jr_init
crypto: caam - pair irq map and dispose in the same function
crypto: ccp - terminate ccp_support array with empty element
crypto: caam - remove unused local variable
crypto: caam - remove dead code
crypto: caam - don't emit ICV check failures to dmesg
hwrng: virtio - drop extra empty line
crypto: replace scatterwalk_sg_next with sg_next
crypto: atmel - Free memory in error path
crypto: doc - remove colons in comments
crypto: seqiv - Ensure that IV size is at least 8 bytes
crypto: cts - Weed out non-CBC algorithms
MAINTAINERS: add linux-crypto to hw random
crypto: cts - Remove bogus use of seqiv
crypto: qat - don't need qat_auth_state struct
crypto: algif_rng - fix sparse non static symbol warning
...
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This feature let us to detect accesses out of bounds of global variables.
This will work as for globals in kernel image, so for globals in modules.
Currently this won't work for symbols in user-specified sections (e.g.
__init, __read_mostly, ...)
The idea of this is simple. Compiler increases each global variable by
redzone size and add constructors invoking __asan_register_globals()
function. Information about global variable (address, size, size with
redzone ...) passed to __asan_register_globals() so we could poison
variable's redzone.
This patch also forces module_alloc() to return 8*PAGE_SIZE aligned
address making shadow memory handling (
kasan_module_alloc()/kasan_module_free() ) more simple. Such alignment
guarantees that each shadow page backing modules address space correspond
to only one module_alloc() allocation.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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MODULE_DEVICE_TABLE() macro used to create aliases to device tables.
Normally alias should have the same type as aliased symbol.
Device tables are arrays, so they have 'struct type##_device_id[x]'
types. Alias created by MODULE_DEVICE_TABLE() will have non-array type -
'struct type##_device_id'.
This inconsistency confuses compiler, it could make a wrong assumption
about variable's size which leads KASan to produce a false positive report
about out of bounds access.
For every global variable compiler calls __asan_register_globals() passing
information about global variable (address, size, size with redzone, name
...) __asan_register_globals() poison symbols redzone to detect possible
out of bounds accesses.
When symbol has an alias __asan_register_globals() will be called as for
symbol so for alias. Compiler determines size of variable by size of
variable's type. Alias and symbol have the same address, so if alias have
the wrong size part of memory that actually belongs to the symbol could be
poisoned as redzone of alias symbol.
By fixing type of alias symbol we will fix size of it, so
__asan_register_globals() will not poison valid memory.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
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For instrumenting global variables KASan will shadow memory backing memory
for modules. So on module loading we will need to allocate memory for
shadow and map it at address in shadow that corresponds to the address
allocated in module_alloc().
__vmalloc_node_range() could be used for this purpose, except it puts a
guard hole after allocated area. Guard hole in shadow memory should be a
problem because at some future point we might need to have a shadow memory
at address occupied by guard hole. So we could fail to allocate shadow
for module_alloc().
Now we have VM_NO_GUARD flag disabling guard page, so we need to pass into
__vmalloc_node_range(). Add new parameter 'vm_flags' to
__vmalloc_node_range() function.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
For instrumenting global variables KASan will shadow memory backing memory
for modules. So on module loading we will need to allocate memory for
shadow and map it at address in shadow that corresponds to the address
allocated in module_alloc().
__vmalloc_node_range() could be used for this purpose, except it puts a
guard hole after allocated area. Guard hole in shadow memory should be a
problem because at some future point we might need to have a shadow memory
at address occupied by guard hole. So we could fail to allocate shadow
for module_alloc().
Add a new vm_struct flag 'VM_NO_GUARD' indicating that vm area doesn't
have a guard hole.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Stack instrumentation allows to detect out of bounds memory accesses for
variables allocated on stack. Compiler adds redzones around every
variable on stack and poisons redzones in function's prologue.
Such approach significantly increases stack usage, so all in-kernel stacks
size were doubled.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
With this patch kasan will be able to catch bugs in memory allocated by
slub. Initially all objects in newly allocated slab page, marked as
redzone. Later, when allocation of slub object happens, requested by
caller number of bytes marked as accessible, and the rest of the object
(including slub's metadata) marked as redzone (inaccessible).
We also mark object as accessible if ksize was called for this object.
There is some places in kernel where ksize function is called to inquire
size of really allocated area. Such callers could validly access whole
allocated memory, so it should be marked as accessible.
Code in slub.c and slab_common.c files could validly access to object's
metadata, so instrumentation for this files are disabled.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Signed-off-by: Dmitry Chernenkov <dmitryc@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Remove static and add function declarations to linux/slub_def.h so it
could be used by kernel address sanitizer.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
virt_to_obj takes kmem_cache address, address of slab page, address x
pointing somewhere inside slab object, and returns address of the
beginning of object.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Add kernel address sanitizer hooks to mark allocated page's addresses as
accessible in corresponding shadow region. Mark freed pages as
inaccessible.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Kernel Address sanitizer (KASan) is a dynamic memory error detector. It
provides fast and comprehensive solution for finding use-after-free and
out-of-bounds bugs.
KASAN uses compile-time instrumentation for checking every memory access,
therefore GCC > v4.9.2 required. v4.9.2 almost works, but has issues with
putting symbol aliases into the wrong section, which breaks kasan
instrumentation of globals.
This patch only adds infrastructure for kernel address sanitizer. It's
not available for use yet. The idea and some code was borrowed from [1].
Basic idea:
The main idea of KASAN is to use shadow memory to record whether each byte
of memory is safe to access or not, and use compiler's instrumentation to
check the shadow memory on each memory access.
Address sanitizer uses 1/8 of the memory addressable in kernel for shadow
memory and uses direct mapping with a scale and offset to translate a
memory address to its corresponding shadow address.
Here is function to translate address to corresponding shadow address:
unsigned long kasan_mem_to_shadow(unsigned long addr)
{
return (addr >> KASAN_SHADOW_SCALE_SHIFT) + KASAN_SHADOW_OFFSET;
}
where KASAN_SHADOW_SCALE_SHIFT = 3.
So for every 8 bytes there is one corresponding byte of shadow memory.
The following encoding used for each shadow byte: 0 means that all 8 bytes
of the corresponding memory region are valid for access; k (1 <= k <= 7)
means that the first k bytes are valid for access, and other (8 - k) bytes
are not; Any negative value indicates that the entire 8-bytes are
inaccessible. Different negative values used to distinguish between
different kinds of inaccessible memory (redzones, freed memory) (see
mm/kasan/kasan.h).
To be able to detect accesses to bad memory we need a special compiler.
Such compiler inserts a specific function calls (__asan_load*(addr),
__asan_store*(addr)) before each memory access of size 1, 2, 4, 8 or 16.
These functions check whether memory region is valid to access or not by
checking corresponding shadow memory. If access is not valid an error
printed.
Historical background of the address sanitizer from Dmitry Vyukov:
"We've developed the set of tools, AddressSanitizer (Asan),
ThreadSanitizer and MemorySanitizer, for user space. We actively use
them for testing inside of Google (continuous testing, fuzzing,
running prod services). To date the tools have found more than 10'000
scary bugs in Chromium, Google internal codebase and various
open-source projects (Firefox, OpenSSL, gcc, clang, ffmpeg, MySQL and
lots of others): [2] [3] [4].
The tools are part of both gcc and clang compilers.
We have not yet done massive testing under the Kernel AddressSanitizer
(it's kind of chicken and egg problem, you need it to be upstream to
start applying it extensively). To date it has found about 50 bugs.
Bugs that we've found in upstream kernel are listed in [5].
We've also found ~20 bugs in out internal version of the kernel. Also
people from Samsung and Oracle have found some.
[...]
As others noted, the main feature of AddressSanitizer is its
performance due to inline compiler instrumentation and simple linear
shadow memory. User-space Asan has ~2x slowdown on computational
programs and ~2x memory consumption increase. Taking into account that
kernel usually consumes only small fraction of CPU and memory when
running real user-space programs, I would expect that kernel Asan will
have ~10-30% slowdown and similar memory consumption increase (when we
finish all tuning).
I agree that Asan can well replace kmemcheck. We have plans to start
working on Kernel MemorySanitizer that finds uses of unitialized
memory. Asan+Msan will provide feature-parity with kmemcheck. As
others noted, Asan will unlikely replace debug slab and pagealloc that
can be enabled at runtime. Asan uses compiler instrumentation, so even
if it is disabled, it still incurs visible overheads.
Asan technology is easily portable to other architectures. Compiler
instrumentation is fully portable. Runtime has some arch-dependent
parts like shadow mapping and atomic operation interception. They are
relatively easy to port."
Comparison with other debugging features:
========================================
KMEMCHECK:
- KASan can do almost everything that kmemcheck can. KASan uses
compile-time instrumentation, which makes it significantly faster than
kmemcheck. The only advantage of kmemcheck over KASan is detection of
uninitialized memory reads.
Some brief performance testing showed that kasan could be
x500-x600 times faster than kmemcheck:
$ netperf -l 30
MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to localhost (127.0.0.1) port 0 AF_INET
Recv Send Send
Socket Socket Message Elapsed
Size Size Size Time Throughput
bytes bytes bytes secs. 10^6bits/sec
no debug: 87380 16384 16384 30.00 41624.72
kasan inline: 87380 16384 16384 30.00 12870.54
kasan outline: 87380 16384 16384 30.00 10586.39
kmemcheck: 87380 16384 16384 30.03 20.23
- Also kmemcheck couldn't work on several CPUs. It always sets
number of CPUs to 1. KASan doesn't have such limitation.
DEBUG_PAGEALLOC:
- KASan is slower than DEBUG_PAGEALLOC, but KASan works on sub-page
granularity level, so it able to find more bugs.
SLUB_DEBUG (poisoning, redzones):
- SLUB_DEBUG has lower overhead than KASan.
- SLUB_DEBUG in most cases are not able to detect bad reads,
KASan able to detect both reads and writes.
- In some cases (e.g. redzone overwritten) SLUB_DEBUG detect
bugs only on allocation/freeing of object. KASan catch
bugs right before it will happen, so we always know exact
place of first bad read/write.
[1] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel
[2] https://code.google.com/p/address-sanitizer/wiki/FoundBugs
[3] https://code.google.com/p/thread-sanitizer/wiki/FoundBugs
[4] https://code.google.com/p/memory-sanitizer/wiki/FoundBugs
[5] https://code.google.com/p/address-sanitizer/wiki/AddressSanitizerForKernel#Trophies
Based on work by Andrey Konovalov.
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Acked-by: Michal Marek <mmarek@suse.cz>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
To be consistent with other compiler attributes introduce __alias(symbol)
macro expanding into __attribute__((alias(#symbol)))
Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrey Konovalov <adech.fo@gmail.com>
Cc: Yuri Gribov <tetra2005@gmail.com>
Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Now that all bitmap formatting usages have been converted to
'%*pb[l]', the separate formatting functions are unnecessary. The
following functions are removed.
* bitmap_scn[list]printf()
* cpumask_scnprintf(), cpulist_scnprintf()
* [__]nodemask_scnprintf(), [__]nodelist_scnprintf()
* seq_bitmap[_list](), seq_cpumask[_list](), seq_nodemask[_list]()
* seq_buf_bitmask()
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
printf family of functions can now format bitmaps using '%*pb[l]' and
all cpumask and nodemask formatting will be converted to use it. To
ease printing these masks with '%*pb[l]' which require two params -
the number of bits and the actual bitmap, this patch implement
cpumask_pr_args() and nodemask_pr_args() which can be used to provide
arguments for '%*pb[l]'
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
bitmap implements two variants of scnprintf functions to format a bitmap
into a string and cpumask and nodemask wrap them to provide equivalent
interfaces. The scnprintf family of functions require a string buffer as
an output target which complicates code paths which just want to print out
the mask through printk for informational or debug purposes as they have
to worry about how large the buffer should be and whether it's too large
to allocate on stack.
Neither cpumask or nodemask provides a guildeline on how large the target
buffer should be forcing users come up with their own solutions - some
allocate an arbitrarily sized buffer which is small enough to allocate on
stack but may be too short in corner cases, other come up with a custom
upper limit calculation considering the output format, some allocate the
buffer dynamically while one resorted to using lock to synchronize access
to a static buffer.
This is an artificial problem which is being solved repeatedly for no
benefit. In a lot of cases, the output area already exists and can be
targeted directly making the intermediate buffer unnecessary. This
patchset teaches printf family of functions how to format bitmaps and
replace the dedicated formatting functions with it.
Pointer formatting is extended to cover bitmap formatting. It uses the
field width for the number of bits instead of precision. The format used
is '%*pb[l]', with the optional trailing 'l' specifying list format
instead of hex masks. For more details, please see 0002.
This patch (of 31):
Currently, the formatting and parsing functions in cpumask.h use
nr_cpumask_bits like other cpumask functions; however, nr_cpumask_bits
is either NR_CPUS or nr_cpu_ids depending on CONFIG_CPUMASK_OFFSTACK.
This leads to inconsistent behaviors.
With CONFIG_NR_CPUS=512 and !CONFIG_CPUMASK_OFFSTACK
# cat /sys/devices/virtual/net/lo/queues/rx-0/rps_cpus
00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000,00000000
# cat /proc/self/status | grep Cpus_allowed:
Cpus_allowed: f
With CONFIG_NR_CPUS=1024 and CONFIG_CPUMASK_OFFSTACK (fedora default)
# cat /sys/devices/virtual/net/lo/queues/rx-0/rps_cpus
0
# cat /proc/self/status | grep Cpus_allowed:
Cpus_allowed: f
Note that /proc/self/status is always using nr_cpu_ids regardless of
config. This is because seq cpumask formattings functions always use
nr_cpu_ids.
Given that the same output fields may switch between the two forms,
converging on nr_cpu_ids always isn't too likely to surprise userland.
This patch updates the formatting and parsing functions in cpumask.h
to always use nr_cpu_ids. There's no point in dealing with CPUs which
aren't even possible on the machine.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: "John W. Linville" <linville@tuxdriver.com>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Chris Metcalf <cmetcalf@tilera.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: Christoph Lameter <cl@linux.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Mike Travis <travis@sgi.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
When a new kernfs node is created, KERNFS_STATIC_NAME is used to avoid
making a separate copy of its name. It's currently only used for sysfs
attributes whose filenames are required to stay accessible and unchanged.
There are rare exceptions where these names are allocated and formatted
dynamically but for the vast majority of cases they're consts in the
rodata section.
Now that kernfs is converted to use kstrdup_const() and kfree_const(),
there's little point in keeping KERNFS_STATIC_NAME around. Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
kstrdup() is often used to duplicate strings where neither source neither
destination will be ever modified. In such case we can just reuse the
source instead of duplicating it. The problem is that we must be sure
that the source is non-modifiable and its life-time is long enough.
I suspect the good candidates for such strings are strings located in
kernel .rodata section, they cannot be modifed because the section is
read-only and their life-time is equal to kernel life-time.
This small patchset proposes alternative version of kstrdup -
kstrdup_const, which returns source string if it is located in .rodata
otherwise it fallbacks to kstrdup. To verify if the source is in
.rodata function checks if the address is between sentinels
__start_rodata, __end_rodata. I guess it should work with all
architectures.
The main patch is accompanied by four patches constifying kstrdup for
cases where situtation described above happens frequently.
I have tested the patchset on mobile platform (exynos4210-trats) and it
saves 3272 string allocations. Since minimal allocation is 32 or 64
bytes depending on Kconfig options the patchset saves respectively about
100KB or 200KB of memory.
Stats from tested platform show that the main offender is sysfs:
By caller:
2260 __kernfs_new_node
631 clk_register+0xc8/0x1b8
318 clk_register+0x34/0x1b8
51 kmem_cache_create
12 alloc_vfsmnt
By string (with count >= 5):
883 power
876 subsystem
135 parameters
132 device
61 iommu_group
...
This patch (of 5):
Add an alternative version of kstrdup which returns pointer to constant
char array. The function checks if input string is in persistent and
read-only memory section, if yes it returns the input string, otherwise it
fallbacks to kstrdup.
kstrdup_const is accompanied by kfree_const performing conditional memory
deallocation of the string.
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Mike Turquette <mturquette@linaro.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Greg KH <greg@kroah.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
