Vivien Didelot [Fri, 4 Sep 2015 18:34:12 +0000 (14:34 -0400)]
net: dsa: mv88e6xxx: rework ATU Flush operation
These Marvell switches have 4 operations to flush or (re)move, all or
only non-static MAC addresses, from the entire set of databases or from
just a particular one.
The value of the EntryState bits will determine if the operation is
either a Flush (0x0) or a Move (0xF).
When moving entries from one port to another, entries will be removed if
the destination port is 0xF.
This patch renames these operations for consistency, add a new generic
_mv88e6xxx_atu_flush_move function, and change _mv88e6xxx_flush_fid to
use it.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Vivien Didelot [Fri, 4 Sep 2015 18:34:11 +0000 (14:34 -0400)]
net: dsa: mv88e6xxx: extract ATU data write access
Other ATU commands need to write the ATU data register. To ease the
introduction of such commands, extract the ATU data write access from
_mv88e6xxx_atu_load to its own function.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Vivien Didelot [Fri, 4 Sep 2015 18:34:10 +0000 (14:34 -0400)]
net: dsa: mv88e6xxx: extract FID write from ATU command
Not every ATU commands apply to an FID, thus remove the FID writing from
mv88e6xxx_atu_cmd and write it explicitly where needed, in order to ease
introduction of such commands.
Signed-off-by: Vivien Didelot <vivien.didelot@savoirfairelinux.com> Signed-off-by: David S. Miller <davem@davemloft.net>
David Ahern [Wed, 2 Sep 2015 20:58:36 +0000 (13:58 -0700)]
net: Allow user to get table id from route lookup
rt_fill_info which is called for 'route get' requests hardcodes the
table id as RT_TABLE_MAIN which is not correct when multiple tables
are used. Use the newly added table id in the rtable to send back
the correct table similar to what is done for IPv6.
To maintain current ABI a new request flag, RTM_F_LOOKUP_TABLE, is
added to indicate the actual table is wanted versus the hardcoded
response.
Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Merge tag 'sound-fix-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"A collection of small fixes since the last update: the HD-audio quirks
as usual with a USB-audio fix and a trivial fix for the old sparc
driver"
* tag 'sound-fix-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Change internal PCM order
ALSA: hda - Fix white noise on Dell M3800
ALSA: hda - Use ALC880_FIXUP_FUJITSU for FSC Amilo M1437
ALSA: hda - Enable headphone jack detect on old Fujitsu laptops
ALSA: sparc: amd7930: Fix module autoload for OF platform driver
ALSA: hda - Add some FIXUP quirks for white noise on Dell laptop.
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"Just a bunch of fixes to squeeze in before -rc1:
- three nouveau regression fixes
- one qxl regression fix
- a bunch of i915 fixes
... and some core displayport/atomic fixes"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux:
drm/nouveau/device: enable c800 quirk for tecra w50
drm/nouveau/clk/gt215: Unbreak engine pausing for GT21x/MCP7x
drm/nouveau/gr/nv04: fix big endian setting on gr context
drm/qxl: validate monitors config modes
drm/i915: Allow DSI dual link to be configured on any pipe
drm/i915: Don't try to use DDR DVFS on CHV when disabled in the BIOS
drm/i915: Fix CSR MMIO address check
drm/i915: Limit the number of loops for reading a split 64bit register
drm/i915: Fix broken mst get_hw_state.
drm/i915: Pass hpd_status_i915[] to intel_get_hpd_pins() in pre-g4x
uapi/drm/i915_drm.h: fix userspace compilation.
drm/i915: Always mark the object as dirty when used by the GPU
drm/dp: Add dp_aux_i2c_speed_khz module param to set the assume i2c bus speed
drm/dp: Adjust i2c-over-aux retry count based on message size and i2c bus speed
drm/dp: Define AUX_RETRY_INTERVAL as 500 us
drm/atomic: Fix bookkeeping with TEST_ONLY, v3.
Dave Airlie [Fri, 11 Sep 2015 04:38:36 +0000 (14:38 +1000)]
Merge branch 'linux-4.3' of git://anongit.freedesktop.org/git/nouveau/linux-2.6 into drm-next
three nouveau regression fixes.
* 'linux-4.3' of git://anongit.freedesktop.org/git/nouveau/linux-2.6:
drm/nouveau/device: enable c800 quirk for tecra w50
drm/nouveau/clk/gt215: Unbreak engine pausing for GT21x/MCP7x
drm/nouveau/gr/nv04: fix big endian setting on gr context
Merge branch 'for-4.3/blkcg' of git://git.kernel.dk/linux-block
Pull blk-cg updates from Jens Axboe:
"A bit later in the cycle, but this has been in the block tree for a a
while. This is basically four patchsets from Tejun, that improve our
buffered cgroup writeback. It was dependent on the other cgroup
changes, but they went in earlier in this cycle.
Series 1 is set of 5 patches that has cgroup writeback updates:
- bdi_writeback iteration fix which could lead to some wb's being
skipped or repeated during e.g. sync under memory pressure.
- Simplification of wb work wait mechanism.
- Writeback tracepoints updated to report cgroup.
Series 2 is is a set of updates for the CFQ cgroup writeback handling:
cfq has always charged all async IOs to the root cgroup. It didn't
have much choice as writeback didn't know about cgroups and there
was no way to tell who to blame for a given writeback IO.
writeback finally grew support for cgroups and now tags each
writeback IO with the appropriate cgroup to charge it against.
This patchset updates cfq so that it follows the blkcg each bio is
tagged with. Async cfq_queues are now shared across cfq_group,
which is per-cgroup, instead of per-request_queue cfq_data. This
makes all IOs follow the weight based IO resource distribution
implemented by cfq.
- Switched from GFP_ATOMIC to GFP_NOWAIT as suggested by Jeff.
- Other misc review points addressed, acks added and rebased.
Series 3 is the blkcg policy cleanup patches:
This patchset contains assorted cleanups for blkcg_policy methods
and blk[c]g_policy_data handling.
- alloc/free added for blkg_policy_data. exit dropped.
- alloc/free added for blkcg_policy_data.
- blk-throttle's async percpu allocation is replaced with direct
allocation.
- all methods now take blk[c]g_policy_data instead of blkcg_gq or
blkcg.
And finally, series 4 is a set of patches cleaning up the blkcg stats
handling:
blkcg's stats have always been somwhat of a mess. This patchset
tries to improve the situation a bit.
- The following patches added to consolidate blkcg entry point and
blkg creation. This is in itself is an improvement and helps
colllecting common stats on bio issue.
- per-blkg stats now accounted on bio issue rather than request
completion so that bio based and request based drivers can behave
the same way. The issue was spotted by Vivek.
- cfq-iosched implements custom recursive stats and blk-throttle
implements custom per-cpu stats. This patchset make blkcg core
support both by default.
- cfq-iosched and blk-throttle keep track of the same stats
multiple times. Unify them"
* 'for-4.3/blkcg' of git://git.kernel.dk/linux-block: (45 commits)
blkcg: use CGROUP_WEIGHT_* scale for io.weight on the unified hierarchy
blkcg: s/CFQ_WEIGHT_*/CFQ_WEIGHT_LEGACY_*/
blkcg: implement interface for the unified hierarchy
blkcg: misc preparations for unified hierarchy interface
blkcg: separate out tg_conf_updated() from tg_set_conf()
blkcg: move body parsing from blkg_conf_prep() to its callers
blkcg: mark existing cftypes as legacy
blkcg: rename subsystem name from blkio to io
blkcg: refine error codes returned during blkcg configuration
blkcg: remove unnecessary NULL checks from __cfqg_set_weight_device()
blkcg: reduce stack usage of blkg_rwstat_recursive_sum()
blkcg: remove cfqg_stats->sectors
blkcg: move io_service_bytes and io_serviced stats into blkcg_gq
blkcg: make blkg_[rw]stat_recursive_sum() to be able to index into blkcg_gq
blkcg: make blkcg_[rw]stat per-cpu
blkcg: add blkg_[rw]stat->aux_cnt and replace cfq_group->dead_stats with it
blkcg: consolidate blkg creation in blkcg_bio_issue_check()
blk-throttle: improve queue bypass handling
blkcg: move root blkg lookup optimization from throtl_lookup_tg() to __blkg_lookup()
blkcg: inline [__]blkg_lookup()
...
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (81 commits)
dma-mapping: consolidate dma_set_mask
dma-mapping: consolidate dma_supported
dma-mapping: cosolidate dma_mapping_error
dma-mapping: consolidate dma_{alloc,free}_noncoherent
dma-mapping: consolidate dma_{alloc,free}_{attrs,coherent}
mm: use vma_is_anonymous() in create_huge_pmd() and wp_huge_pmd()
mm: make sure all file VMAs have ->vm_ops set
mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
mm: mark most vm_operations_struct const
namei: fix warning while make xmldocs caused by namei.c
ipc: convert invalid scenarios to use WARN_ON
zlib_deflate/deftree: remove bi_reverse()
lib/decompress_unlzma: Do a NULL check for pointer
lib/decompressors: use real out buf size for gunzip with kernel
fs/affs: make root lookup from blkdev logical size
sysctl: fix int -> unsigned long assignments in INT_MIN case
kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo
kexec: align crash_notes allocation to make it be inside one physical page
kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
kexec: split kexec_load syscall from kexec core code
...
Merge tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull late ARM SoC updates from Kevin Hilman:
"This is a collection of a few late fixes and other misc stuff that had
dependencies on things being merged from other trees.
The bulk of the changes are for samsung/exynos SoCs for some changes
that needed a few minor reworks so ended up a bit late. The others
are mainly for qcom SoCs: a couple fixes and some DTS updates"
* tag 'armsoc-late' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (37 commits)
ARM: multi_v7_defconfig: Enable PBIAS regulator
soc: qcom: smd: Correct fBLOCKREADINTR handling
soc: qcom: smd: Use correct remote processor ID
soc: qcom: smem: Fix errant private access
ARM: dts: qcom: msm8974-sony-xperia-honami: Use stdout-path
ARM: dts: qcom: msm8960-cdp: Use stdout-path
ARM: dts: qcom: msm8660-surf: Use stdout-path
ARM: dts: qcom: ipq8064-ap148: Use stdout-path
ARM: dts: qcom: apq8084-mtp: Use stdout-path
ARM: dts: qcom: apq8084-ifc6540: Use stdout-path
ARM: dts: qcom: apq8074-dragonboard: Use stdout-path
ARM: dts: qcom: apq8064-ifc6410: Use stdout-path
ARM: dts: qcom: apq8064-cm-qs600: Use stdout-path
ARM: dts: qcom: Label serial nodes for aliasing and stdout-path
reset: ath79: Fix missing spin_lock_init
reset: Add (devm_)reset_control_get stub functions
ARM: EXYNOS: switch to using generic cpufreq driver for exynos4x12
cpufreq: exynos: Remove unselectable rule for arm-exynos-cpufreq.o
ARM: dts: add iommu property to JPEG device for exynos4
ARM: dts: enable SPI1 for exynos4412-odroidu3
...
Dave Airlie [Fri, 11 Sep 2015 00:52:37 +0000 (10:52 +1000)]
Merge tag 'topic/drm-fixes-2015-09-09' of git://anongit.freedesktop.org/drm-intel into drm-next
bunch of drm fixes.
* tag 'topic/drm-fixes-2015-09-09' of git://anongit.freedesktop.org/drm-intel:
drm/dp: Add dp_aux_i2c_speed_khz module param to set the assume i2c bus speed
drm/dp: Adjust i2c-over-aux retry count based on message size and i2c bus speed
drm/dp: Define AUX_RETRY_INTERVAL as 500 us
drm/atomic: Fix bookkeeping with TEST_ONLY, v3.
Dave Airlie [Fri, 11 Sep 2015 00:52:08 +0000 (10:52 +1000)]
Merge tag 'drm-intel-next-fixes-2015-09-10' of git://anongit.freedesktop.org/drm-intel into drm-next
Fixes headed for v4.3-rc1, including Maarten's DP MST state checker fix
you requested.
* tag 'drm-intel-next-fixes-2015-09-10' of git://anongit.freedesktop.org/drm-intel:
drm/i915: Allow DSI dual link to be configured on any pipe
drm/i915: Don't try to use DDR DVFS on CHV when disabled in the BIOS
drm/i915: Fix CSR MMIO address check
drm/i915: Limit the number of loops for reading a split 64bit register
drm/i915: Fix broken mst get_hw_state.
drm/i915: Pass hpd_status_i915[] to intel_get_hpd_pins() in pre-g4x
uapi/drm/i915_drm.h: fix userspace compilation.
drm/i915: Always mark the object as dirty when used by the GPU
Jonathon Jongsma [Thu, 20 Aug 2015 19:04:32 +0000 (14:04 -0500)]
drm/qxl: validate monitors config modes
Due to some recent changes in
drm_helper_probe_single_connector_modes_merge_bits(), old custom modes
were not being pruned properly. In current kernels,
drm_mode_validate_basic() is called to sanity-check each mode in the
list. If the sanity-check passes, the mode's status gets set to to
MODE_OK. In older kernels this check was not done, so old custom modes
would still have a status of MODE_UNVERIFIED at this point, and would
therefore be pruned later in the function.
As a result of this new behavior, the list of modes for a device always
includes every custom mode ever configured for the device, with the
largest one listed first. Since desktop environments usually choose the
first preferred mode when a hotplug event is emitted, this had the
result of making it very difficult for the user to reduce the size of
the display.
The qxl driver did implement the mode_valid connector function, but it
was empty. In order to restore the old behavior where old custom modes
are pruned, we implement a proper mode_valid function for the qxl
driver. This function now checks each mode against the last configured
custom mode and the list of standard modes. If the mode doesn't match
any of these, its status is set to MODE_BAD so that it will be pruned as
expected.
Signed-off-by: Jonathon Jongsma <jjongsma@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com>
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull more kvm updates from Paolo Bonzini:
"ARM:
- Full debug support for arm64
- Active state switching for timer interrupts
- Lazy FP/SIMD save/restore for arm64
- Generic ARMv8 target
PPC:
- Book3S: A few bug fixes
- Book3S: Allow micro-threading on POWER8
x86:
- Compiler warnings
Generic:
- Adaptive polling for guest halt"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (49 commits)
kvm: irqchip: fix memory leak
kvm: move new trace event outside #ifdef CONFIG_KVM_ASYNC_PF
KVM: trace kvm_halt_poll_ns grow/shrink
KVM: dynamic halt-polling
KVM: make halt_poll_ns per-vCPU
Silence compiler warning in arch/x86/kvm/emulate.c
kvm: compile process_smi_save_seg_64() only for x86_64
KVM: x86: avoid uninitialized variable warning
KVM: PPC: Book3S: Fix typo in top comment about locking
KVM: PPC: Book3S: Fix size of the PSPB register
KVM: PPC: Book3S HV: Exit on H_DOORBELL if HOST_IPI is set
KVM: PPC: Book3S HV: Fix race in starting secondary threads
KVM: PPC: Book3S: correct width in XER handling
KVM: PPC: Book3S HV: Fix preempted vcore stolen time calculation
KVM: PPC: Book3S HV: Fix preempted vcore list locking
KVM: PPC: Book3S HV: Implement H_CLEAR_REF and H_CLEAR_MOD
KVM: PPC: Book3S HV: Fix bug in dirty page tracking
KVM: PPC: Book3S HV: Fix race in reading change bit when removing HPTE
KVM: PPC: Book3S HV: Implement dynamic micro-threading on POWER8
KVM: PPC: Book3S HV: Make use of unused threads when running guests
...
Merge tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip
Pull xen terminology fixes from David Vrabel:
"Use the correct GFN/BFN terms more consistently"
* tag 'for-linus-4.3-rc0b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
xen/xenbus: Rename the variable xen_store_mfn to xen_store_gfn
xen/privcmd: Further s/MFN/GFN/ clean-up
hvc/xen: Further s/MFN/GFN clean-up
video/xen-fbfront: Further s/MFN/GFN clean-up
xen/tmem: Use xen_page_to_gfn rather than pfn_to_gfn
xen: Use correctly the Xen memory terminologies
arm/xen: implement correctly pfn_to_mfn
xen: Make clear that swiotlb and biomerge are dealing with DMA address
1) Fix out-of-bounds array access in netfilter ipset, from Jozsef
Kadlecsik.
2) Use correct free operation on netfilter conntrack templates, from
Daniel Borkmann.
3) Fix route leak in SCTP, from Marcelo Ricardo Leitner.
4) Fix sizeof(pointer) in mac80211, from Thierry Reding.
5) Fix cache pointer comparison in ip6mr leading to missed unlock of
mrt_lock. From Richard Laing.
6) rds_conn_lookup() needs to consider network namespace in key
comparison, from Sowmini Varadhan.
7) Fix deadlock in TIPC code wrt broadcast link wakeups, from Kolmakov
Dmitriy.
8) Fix fd leaks in bpf syscall, from Daniel Borkmann.
9) Fix error recovery when installing ipv6 multipath routes, we would
delete the old route before we would know if we could fully commit
to the new set of nexthops. Fix from Roopa Prabhu.
10) Fix run-time suspend problems in r8152, from Hayes Wang.
11) In fec, don't program the MAC address into the chip when the clocks
are gated off. From Fugang Duan.
12) Fix poll behavior for netlink sockets when using rx ring mmap, from
Daniel Borkmann.
13) Don't allocate memory with GFP_KERNEL from get_stats64 in r8169
driver, from Corinna Vinschen.
14) In TCP Cubic congestion control, handle idle periods better where we
are application limited, in order to keep cwnd from growing out of
control. From Eric Dumzet.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
tcp_cubic: better follow cubic curve after idle period
tcp: generate CA_EVENT_TX_START on data frames
xen-netfront: respect user provided max_queues
xen-netback: respect user provided max_queues
r8169: Fix sleeping function called during get_stats64, v2
ether: add IEEE 1722 ethertype - TSN
netlink, mmap: fix edge-case leakages in nf queue zero-copy
netlink, mmap: don't walk rx ring on poll if receive queue non-empty
cxgb4: changes for new firmware 1.14.4.0
net: fec: add netif status check before set mac address
r8152: fix the runtime suspend issues
r8152: split DRIVER_VERSION
ipv6: fix ifnullfree.cocci warnings
add microchip LAN88xx phy driver
stmmac: fix check for phydev being open
net: qlcnic: delete redundant memsets
net: mv643xx_eth: use kzalloc
net: jme: use kzalloc() instead of kmalloc+memset
net: cavium: liquidio: use kzalloc in setup_glist()
net: ipv6: use common fib_default_rule_pref
...
Almost everyone implements dma_set_mask the same way, although some time
that's hidden in ->set_dma_mask methods.
This patch consolidates those into a common implementation that either
calls ->set_dma_mask if present or otherwise uses the default
implementation. Some architectures used to only call ->set_dma_mask
after the initial checks, and those instance have been fixed to do the
full work. h8300 implemented dma_set_mask bogusly as a no-ops and has
been fixed.
Unfortunately some architectures overload unrelated semantics like changing
the dma_ops into it so we still need to allow for an architecture override
for now.
[jcmvbkbc@gmail.com: fix xtensa] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Jonas Bonn <jonas@southpole.se> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most architectures just call into ->dma_supported, but some also return 1
if the method is not present, or 0 if no dma ops are present (although
that should never happeb). Consolidate this more broad version into
common code.
Also fix h8300 which inorrectly always returned 0, which would have been
a problem if it's dma_set_mask implementation wasn't a similarly buggy
noop.
As a few architectures have much more elaborate implementations, we
still allow for arch overrides.
[jcmvbkbc@gmail.com: fix xtensa] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Jonas Bonn <jonas@southpole.se> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Most architectures do not support non-coherent allocations and either
define dma_{alloc,free}_noncoherent to their coherent versions or stub
them out.
Openrisc uses dma_{alloc,free}_attrs to implement them, and only Mips
implements them directly.
This patch moves the Openrisc version to common code, and handles the
DMA_ATTR_NON_CONSISTENT case in the mips dma_map_ops instance.
Note that actual non-coherent allocations require a dma_cache_sync
implementation, so if non-coherent allocations didn't work on
an architecture before this patch they still won't work after it.
[jcmvbkbc@gmail.com: fix xtensa] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Jonas Bonn <jonas@southpole.se> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Since 2009 we have a nice asm-generic header implementing lots of DMA API
functions for architectures using struct dma_map_ops, but unfortunately
it's still missing a lot of APIs that all architectures still have to
duplicate.
This series consolidates the remaining functions, although we still need
arch opt outs for two of them as a few architectures have very
non-standard implementations.
This patch (of 5):
The coherent DMA allocator works the same over all architectures supporting
dma_map operations.
This patch consolidates them and converges the minor differences:
- the debug_dma helpers are now called from all architectures, including
those that were previously missing them
- dma_alloc_from_coherent and dma_release_from_coherent are now always
called from the generic alloc/free routines instead of the ops
dma-mapping-common.h always includes dma-coherent.h to get the defintions
for them, or the stubs if the architecture doesn't support this feature
- checks for ->alloc / ->free presence are removed. There is only one
magic instead of dma_map_ops without them (mic_dma_ops) and that one
is x86 only anyway.
Besides that only x86 needs special treatment to replace a default devices
if none is passed and tweak the gfp_flags. An optional arch hook is provided
for that.
[linux@roeck-us.net: fix build]
[jcmvbkbc@gmail.com: fix xtensa] Signed-off-by: Christoph Hellwig <hch@lst.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Russell King <linux@arm.linux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Michal Simek <monstr@monstr.eu> Cc: Jonas Bonn <jonas@southpole.se> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Guan Xuetao <gxt@mprc.pku.edu.cn> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm, mpx: add "vm_flags_t vm_flags" arg to do_mmap_pgoff()
Add the additional "vm_flags_t vm_flags" argument to do_mmap_pgoff(),
rename it to do_mmap(), and re-introduce do_mmap_pgoff() as a simple
wrapper on top of do_mmap(). Perhaps we should update the callers of
do_mmap_pgoff() and kill it later.
This way mpx_mmap() can simply call do_mmap(vm_flags => VM_MPX) and do not
play with vm internals.
After this change mmap_region() has a single user outside of mmap.c,
arch/tile/mm/elf.c:arch_setup_additional_pages(). It would be nice to
change arch/tile/ and unexport mmap_region().
[kirill@shutemov.name: fix build]
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Dave Hansen <dave.hansen@linux.intel.com> Tested-by: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Ingo Molnar <mingo@elte.hu> Cc: Minchan Kim <minchan@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
namei: fix warning while make xmldocs caused by namei.c
Fix the following warnings:
Warning(.//fs/namei.c:2422): No description found for parameter 'nd'
Warning(.//fs/namei.c:2422): Excess function parameter 'nameidata'
description in 'path_mountpoint'
Signed-off-by: Masanari Iida <standby24x7@gmail.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Considering Linus' past rants about the (ab)use of BUG in the kernel, I
took a look at how we deal with such calls in ipc. Given that any errors
or corruption in ipc code are most likely contained within the set of
processes participating in the broken mechanisms, there aren't really many
strong fatal system failure scenarios that would require a BUG call.
Also, if something is seriously wrong, ipc might not be the place for such
a BUG either.
1. For example, recently, a customer hit one of these BUG_ONs in shm
after failing shm_lock(). A busted ID imho does not merit a BUG_ON,
and WARN would have been better.
2. MSG_COPY functionality of posix msgrcv(2) for checkpoint/restore.
I don't see how we can hit this anyway -- at least it should be IS_ERR.
The 'copy' arg from do_msgrcv is always set by calling prepare_copy()
first and foremost. We could also probably drop this check altogether.
Either way, it does not merit a BUG_ON.
3. No ->fault() callback for the fs getting the corresponding page --
seems selfish to make the system unusable.
Yinghai Lu [Wed, 9 Sep 2015 22:39:12 +0000 (15:39 -0700)]
lib/decompressors: use real out buf size for gunzip with kernel
When loading x86 64bit kernel above 4GiB with patched grub2, got kernel
gunzip error.
| early console in decompress_kernel
| decompress_kernel:
| input: [0x807f2143b4-0x807ff61aee]
| output: [0x807cc00000-0x807f3ea29b] 0x027ea29c: output_len
| boot via startup_64
| KASLR using RDTSC...
| new output: [0x46fe000000-0x470138cfff] 0x0338d000: output_run_size
| decompress: [0x46fe000000-0x47007ea29b] <=== [0x807f2143b4-0x807ff61aee]
|
| Decompressing Linux... gz...
|
| uncompression error
|
| -- System halted
the new buffer is at 0x46fe000000ULL, decompressor_gzip is using
0xffffffb901ffffff as out_len. gunzip in lib/zlib_inflate/inflate.c cap
that len to 0x01ffffff and decompress fails later.
We could hit this problem with crashkernel booting that uses kexec loading
kernel above 4GiB.
We have decompress_* support:
1. inbuf[]/outbuf[] for kernel preboot.
2. inbuf[]/flush() for initramfs
3. fill()/flush() for initrd.
This bug only affect kernel preboot path that use outbuf[].
Add __decompress and take real out_buf_len for gunzip instead of guessing
wrong buf size.
Fixes: 1431574a1c4 (lib/decompressors: fix "no limit" output buffer length) Signed-off-by: Yinghai Lu <yinghai@kernel.org> Cc: Alexandre Courbot <acourbot@nvidia.com> Cc: Jon Medhurst <tixy@linaro.org> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/affs: make root lookup from blkdev logical size
This patch resolves https://bugzilla.kernel.org/show_bug.cgi?id=16531.
When logical blkdev size > 512 then sector numbers become larger than the
device can support.
Make affs start lookup based on the device's logical sector size instead
of 512.
Reported-by: Mark <markk@clara.co.uk> Suggested-by: Mark <markk@clara.co.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
sysctl: fix int -> unsigned long assignments in INT_MIN case
The following
if (val < 0)
*lvalp = (unsigned long)-val;
is incorrect because the compiler is free to assume -val to be positive
and use a sign-extend instruction for extending the bit pattern. This is
a problem if val == INT_MIN:
Baoquan He [Wed, 9 Sep 2015 22:39:03 +0000 (15:39 -0700)]
kexec: export KERNEL_IMAGE_SIZE to vmcoreinfo
In x86_64, since v2.6.26 the KERNEL_IMAGE_SIZE is changed to 512M, and
accordingly the MODULES_VADDR is changed to 0xffffffffa0000000. However,
in v3.12 Kees Cook introduced kaslr to randomise the location of kernel.
And the kernel text mapping addr space is enlarged from 512M to 1G. That
means now KERNEL_IMAGE_SIZE is variable, its value is 512M when kaslr
support is not compiled in and 1G when kaslr support is compiled in.
Accordingly the MODULES_VADDR is changed too to be:
So when kaslr is compiled in and enabled, the kernel text mapping addr
space and modules vaddr space need be adjusted. Otherwise makedumpfile
will collapse since the addr for some symbols is not correct.
Hence KERNEL_IMAGE_SIZE need be exported to vmcoreinfo and got in
makedumpfile to help calculate MODULES_VADDR.
Signed-off-by: Baoquan He <bhe@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Baoquan He [Wed, 9 Sep 2015 22:39:00 +0000 (15:39 -0700)]
kexec: align crash_notes allocation to make it be inside one physical page
People reported that crash_notes in /proc/vmcore were corrupted and this
cause crash kdump failure. With code debugging and log we got the root
cause. This is because percpu variable crash_notes are allocated in 2
vmalloc pages. Currently percpu is based on vmalloc by default. Vmalloc
can't guarantee 2 continuous vmalloc pages are also on 2 continuous
physical pages. So when 1st kernel exports the starting address and size
of crash_notes through sysfs like below:
kdump kernel use them to get the content of crash_notes. However the 2nd
part may not be in the next neighbouring physical page as we expected if
crash_notes are allocated accross 2 vmalloc pages. That's why
nhdr_ptr->n_namesz or nhdr_ptr->n_descsz could be very huge in
update_note_header_size_elf64() and cause note header merging failure or
some warnings.
In this patch change to call __alloc_percpu() to passed in the align value
by rounding crash_notes_size up to the nearest power of two. This makes
sure the crash_notes is allocated inside one physical page since
sizeof(note_buf_t) in all ARCHS is smaller than PAGE_SIZE. Meanwhile add
a BUILD_BUG_ON to break compile if size is bigger than PAGE_SIZE since
crash_notes definitely will be in 2 pages. That need be avoided, and need
be reported if it's unavoidable.
[akpm@linux-foundation.org: use correct comment layout] Signed-off-by: Baoquan He <bhe@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Young <dyoung@redhat.com> Cc: Lisa Mitchell <lisa.mitchell@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kexec: remove unnecessary test in kimage_alloc_crash_control_pages()
Transforming PFN(Page Frame Number) to struct page is never failure, so we
can simplify the code logic to do the image->control_page assignment
directly in the loop, and remove the unnecessary conditional judgement.
Signed-off-by: Minfei Huang <mnfhuang@gmail.com> Acked-by: Dave Young <dyoung@redhat.com> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Simon Horman <horms@verge.net.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Dave Young [Wed, 9 Sep 2015 22:38:55 +0000 (15:38 -0700)]
kexec: split kexec_load syscall from kexec core code
There are two kexec load syscalls, kexec_load another and kexec_file_load.
kexec_file_load has been splited as kernel/kexec_file.c. In this patch I
split kexec_load syscall code to kernel/kexec.c.
And add a new kconfig option KEXEC_CORE, so we can disable kexec_load and
use kexec_file_load only, or vice verse.
The original requirement is from Ted Ts'o, he want kexec kernel signature
being checked with CONFIG_KEXEC_VERIFY_SIG enabled. But kexec-tools use
kexec_load syscall can bypass the checking.
Vivek Goyal proposed to create a common kconfig option so user can compile
in only one syscall for loading kexec kernel. KEXEC/KEXEC_FILE selects
KEXEC_CORE so that old config files still work.
Because there's general code need CONFIG_KEXEC_CORE, so I updated all the
architecture Kconfig with a new option KEXEC_CORE, and let KEXEC selects
KEXEC_CORE in arch Kconfig. Also updated general kernel code with to
kexec_load syscall.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Dave Young <dyoung@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Petr Tesarik <ptesarik@suse.cz> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Josh Boyer <jwboyer@fedoraproject.org> Cc: David Howells <dhowells@redhat.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>
fs: Don't dump core if the corefile would become world-readable.
On a filesystem like vfat, all files are created with the same owner
and mode independent of who created the file. When a vfat filesystem
is mounted with root as owner of all files and read access for everyone,
root's processes left world-readable coredumps on it (but other
users' processes only left empty corefiles when given write access
because of the uid mismatch).
Given that the old behavior was inconsistent and insecure, I don't see
a problem with changing it. Now, all processes refuse to dump core unless
the resulting corefile will only be readable by their owner.
Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs: if a coredump already exists, unlink and recreate with O_EXCL
It was possible for an attacking user to trick root (or another user) into
writing his coredumps into an attacker-readable, pre-existing file using
rename() or link(), causing the disclosure of secret data from the victim
process' virtual memory. Depending on the configuration, it was also
possible to trick root into overwriting system files with coredumps. Fix
that issue by never writing coredumps into existing files.
Requirements for the attack:
- The attack only applies if the victim's process has a nonzero
RLIMIT_CORE and is dumpable.
- The attacker can trick the victim into coredumping into an
attacker-writable directory D, either because the core_pattern is
relative and the victim's cwd is attacker-writable or because an
absolute core_pattern pointing to a world-writable directory is used.
- The attacker has one of these:
A: on a system with protected_hardlinks=0:
execute access to a folder containing a victim-owned,
attacker-readable file on the same partition as D, and the
victim-owned file will be deleted before the main part of the attack
takes place. (In practice, there are lots of files that fulfill
this condition, e.g. entries in Debian's /var/lib/dpkg/info/.)
This does not apply to most Linux systems because most distros set
protected_hardlinks=1.
B: on a system with protected_hardlinks=1:
execute access to a folder containing a victim-owned,
attacker-readable and attacker-writable file on the same partition
as D, and the victim-owned file will be deleted before the main part
of the attack takes place.
(This seems to be uncommon.)
C: on any system, independent of protected_hardlinks:
write access to a non-sticky folder containing a victim-owned,
attacker-readable file on the same partition as D
(This seems to be uncommon.)
The basic idea is that the attacker moves the victim-owned file to where
he expects the victim process to dump its core. The victim process dumps
its core into the existing file, and the attacker reads the coredump from
it.
If the attacker can't move the file because he does not have write access
to the containing directory, he can instead link the file to a directory
he controls, then wait for the original link to the file to be deleted
(because the kernel checks that the link count of the corefile is 1).
A less reliable variant that requires D to be non-sticky works with link()
and does not require deletion of the original link: link() the file into
D, but then unlink() it directly before the kernel performs the link count
check.
On systems with protected_hardlinks=0, this variant allows an attacker to
not only gain information from coredumps, but also clobber existing,
victim-writable files with coredumps. (This could theoretically lead to a
privilege escalation.)
Signed-off-by: Jann Horn <jann@thejh.net> Cc: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
kmod: handle UMH_WAIT_PROC from system unbound workqueue
The UMH_WAIT_PROC handler runs in its own thread in order to make sure
that waiting for the exec kernel thread completion won't block other
usermodehelper queued jobs.
On older workqueue implementations, worklets couldn't sleep without
blocking the rest of the queue. But now the workqueue subsystem handles
that. Khelper still had the older limitation due to its singlethread
properties but we replaced it to system unbound workqueues.
Those are affine to the current node and can block up to some number of
instances.
They are a good candidate to handle UMH_WAIT_PROC assuming that we have
enough system unbound workers to handle lots of parallel usermodehelper
jobs.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: 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>
We need to launch the usermodehelper kernel threads with the widest
affinity and this is partly why we use khelper. This workqueue has
unbound properties and thus a wide affinity inherited by all its children.
Now khelper also has special properties that we aren't much interested in:
ordered and singlethread. There is really no need about ordering as all
we do is creating kernel threads. This can be done concurrently. And
singlethread is a useless limitation as well.
The workqueue engine already proposes generic unbound workqueues that
don't share these useless properties and handle well parallel jobs.
The only worrysome specific is their affinity to the node of the current
CPU. It's fine for creating the usermodehelper kernel threads but those
inherit this affinity for longer jobs such as requesting modules.
This patch proposes to use these node affine unbound workqueues assuming
that a node is sufficient to handle several parallel usermodehelper
requests.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: 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>
kmod: add up-to-date explanations on the purpose of each asynchronous levels
There seem to be quite some confusions on the comments, likely due to
changes that came after them.
Now since it's very non obvious why we have 3 levels of asynchronous code
to implement usermodehelpers, it's important to comment in detail the
reason of this layout.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rik van Riel <riel@redhat.com> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: Christoph Lameter <cl@linux.com> Cc: 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>
This patchset does a bunch of cleanups and converts khelper to use system
unbound workqueues. The 3 first patches should be uncontroversial. The
last 2 patches are debatable.
Kmod creates kernel threads that perform userspace jobs and we want those
to have a large affinity in order not to contend busy CPUs. This is
(partly) why we use khelper which has a wide affinity that the kernel
threads it create can inherit from. Now khelper is a dedicated workqueue
that has singlethread properties which we aren't interested in.
Hence those two debatable changes:
_ We would like to use generic workqueues. System unbound workqueues are
a very good candidate but they are not wide affine, only node affine.
Now probably a node is enough to perform many parallel kmod jobs.
_ We would like to remove the wait_for_helper kernel thread (UMH_WAIT_PROC
handler) to use the workqueue. It means that if the workqueue blocks,
and no other worker can take pending kmod request, we can be screwed.
Now if we have 512 threads, this should be enough.
This patch (of 5):
Underscores on function names aren't much verbose to explain the purpose
of a function. And kmod has interesting such flavours.
kmod: correct documentation of return status of request_module
If request_module() successfully runs modprobe, but modprobe exits with a
non-zero status, then the return value from request_module() will be that
(positive) error status. So the return from request_module can be:
negative errno
zero for success
positive exit code.
hfs: fix B-tree corruption after insertion at position 0
Fix B-tree corruption when a new record is inserted at position 0 in the
node in hfs_brec_insert().
This is an identical change to the corresponding hfs b-tree code to Sergei
Antonov's "hfsplus: fix B-tree corruption after insertion at position 0",
to keep similar code paths in the hfs and hfsplus drivers in sync, where
appropriate.
Signed-off-by: Hin-Tak Leung <htl10@users.sourceforge.net> Cc: Sergei Antonov <saproj@gmail.com> Cc: Joe Perches <joe@perches.com> Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com> Cc: Anton Altaparmakov <anton@tuxera.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hfs,hfsplus: cache pages correctly between bnode_create and bnode_free
Pages looked up by __hfs_bnode_create() (called by hfs_bnode_create() and
hfs_bnode_find() for finding or creating pages corresponding to an inode)
are immediately kmap()'ed and used (both read and write) and kunmap()'ed,
and should not be page_cache_release()'ed until hfs_bnode_free().
This patch fixes a problem I first saw in July 2012: merely running "du"
on a large hfsplus-mounted directory a few times on a reasonably loaded
system would get the hfsplus driver all confused and complaining about
B-tree inconsistencies, and generates a "BUG: Bad page state". Most
recently, I can generate this problem on up-to-date Fedora 22 with shipped
kernel 4.0.5, by running "du /" (="/" + "/home" + "/mnt" + other smaller
mounts) and "du /mnt" simultaneously on two windows, where /mnt is a
lightly-used QEMU VM image of the full Mac OS X 10.9:
After applying the patch, I was able to run "du /" (60+ times) and "du
/mnt" (150+ times) continuously and simultaneously for 6+ hours.
There are many reports of the hfsplus driver getting confused under load
and generating "BUG: Bad page state" or other similar issues over the
years. [1]
The unpatched code [2] has always been wrong since it entered the kernel
tree. The only reason why it gets away with it is that the
kmap/memcpy/kunmap follow very quickly after the page_cache_release() so
the kernel has not had a chance to reuse the memory for something else,
most of the time.
The current RW driver appears to have followed the design and development
of the earlier read-only hfsplus driver [3], where-by version 0.1 (Dec
2001) had a B-tree node-centric approach to
read_cache_page()/page_cache_release() per bnode_get()/bnode_put(),
migrating towards version 0.2 (June 2002) of caching and releasing pages
per inode extents. When the current RW code first entered the kernel [2]
in 2005, there was an REF_PAGES conditional (and "//" commented out code)
to switch between B-node centric paging to inode-centric paging. There
was a mistake with the direction of one of the REF_PAGES conditionals in
__hfs_bnode_create(). In a subsequent "remove debug code" commit [4], the
read_cache_page()/page_cache_release() per bnode_get()/bnode_put() were
removed, but a page_cache_release() was mistakenly left in (propagating
the "REF_PAGES <-> !REF_PAGE" mistake), and the commented-out
page_cache_release() in bnode_release() (which should be spanned by
!REF_PAGES) was never enabled.
References:
[1]:
Michael Fox, Apr 2013
http://www.spinics.net/lists/linux-fsdevel/msg63807.html
("hfsplus volume suddenly inaccessable after 'hfs: recoff %d too large'")
Sasha Levin, Feb 2015
http://lkml.org/lkml/2015/2/20/85 ("use after free")
Jan Harkes [Wed, 9 Sep 2015 22:38:01 +0000 (15:38 -0700)]
fs/coda: fix readlink buffer overflow
Dan Carpenter discovered a buffer overflow in the Coda file system
readlink code. A userspace file system daemon can return a 4096 byte
result which then triggers a one byte write past the allocated readlink
result buffer.
This does not trigger with an unmodified Coda implementation because Coda
has a 1024 byte limit for symbolic links, however other userspace file
systems using the Coda kernel module could be affected.
Although this is an obvious overflow, I don't think this has to be handled
as too sensitive from a security perspective because the overflow is on
the Coda userspace daemon side which already needs root to open Coda's
kernel device and to mount the file system before we get to the point that
links can be read.
[akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Jan Harkes <jaharkes@cs.cmu.edu> Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 9 Sep 2015 22:37:58 +0000 (15:37 -0700)]
checkpatch: add constant comparison on left side test
"CONST <comparison> variable" checks like:
if (NULL != foo)
and
while (0 < bar(...))
where a constant (or what appears to be a constant like an upper case
identifier) is on the left of a comparison are generally preferred to be
written using the constant on the right side like:
if (foo != NULL)
and
while (bar(...) > 0)
Add a test for this.
Add a --fix option too, but only do it when the code is immediately
surrounded by parentheses to avoid misfixing things like "(0 < bar() +
constant)"
Signed-off-by: Joe Perches <joe@perches.com> Cc: Nicolas Morey Chaisemartin <nmorey@kalray.eu> Cc: Viresh Kumar <viresh.kumar@linaro.org> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 9 Sep 2015 22:37:55 +0000 (15:37 -0700)]
checkpatch: add __pmem to $Sparse annotations
commit 61031952f4c8 ("arch, x86: pmem api for ensuring durability of
persistent memory updates") added a new __pmem annotation for sparse
verification. Add __pmem to the $Sparse variable so checkpatch can
appropriately ignore uses of this attribute too.
Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Acked-by: Andy Whitcroft <apw@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Joe Perches [Wed, 9 Sep 2015 22:37:41 +0000 (15:37 -0700)]
checkpatch: always check block comment styles
Some of the block comment tests that are used only for networking are
appropriate for all patches.
For example, these styles are not encouraged:
/*
block comment without introductory *
*/
and
/*
* block comment with line terminating */
Remove the networking specific test and add comments.
There are some infrequent false positives where code is lazily
commented out using /* and */ rather than using #if 0/#endif blocks
like:
/* case foo:
case bar: */
case baz:
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>
Joe Perches [Wed, 9 Sep 2015 22:37:27 +0000 (15:37 -0700)]
checkpatch: add warning on BUG/BUG_ON use
Using BUG/BUG_ON crashes the kernel and is just unfriendly.
Enable code that emits a warning on BUG/BUG_ON use.
Make the code emit the message at WARNING level when scanning a patch and
at CHECK level when scanning files so that script users don't feel an
obligation to fix code that might be above their pay grade.
Signed-off-by: Joe Perches <joe@perches.com> Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Tested-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Wang Long [Wed, 9 Sep 2015 22:37:22 +0000 (15:37 -0700)]
lib/test_kasan.c: make kmalloc_oob_krealloc_less more correctly
In kmalloc_oob_krealloc_less, I think it is better to test
the size2 boundary.
If we do not call krealloc, the access of position size1 will still cause
out-of-bounds and access of position size2 does not. After call krealloc,
the access of position size2 cause out-of-bounds. So using size2 is more
correct.
Signed-off-by: Wang Long <long.wanglong@huawei.com> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
To further clarify the purpose of the "esc" argument, rename it to "only"
to reflect that it is a limit, not a list of additional characters to
escape.
hexdump: do not print debug dumps for !CONFIG_DEBUG
print_hex_dump_debug() is likely supposed to be analogous to pr_debug() or
dev_dbg() & friends. Currently it will adhere to dynamic debug, but will
not stub out prints if CONFIG_DEBUG is not set. Let's make it do the
right thing, because I am tired of having my dmesg buffer full of hex
dumps on production systems.
Pan Xinhui [Wed, 9 Sep 2015 22:37:08 +0000 (15:37 -0700)]
lib/bitmap.c: bitmap_parselist can accept string with whitespaces on head or tail
In __bitmap_parselist we can accept whitespaces on head or tail during
every parsing procedure. If input has valid ranges, there is no reason to
reject the user.
For example, bitmap_parselist(" 1-3, 5, ", &mask, nmaskbits). After
separating the string, we get " 1-3", " 5", and " ". It's possible and
reasonable to accept such string as long as the parsing result is correct.
Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pan Xinhui [Wed, 9 Sep 2015 22:37:05 +0000 (15:37 -0700)]
lib/bitmap.c: fix a special string handling bug in __bitmap_parselist
If string end with '-', for exapmle, bitmap_parselist("1,0-",&mask,
nmaskbits), It is not in a valid pattern, so add a check after loop.
Return -EINVAL on such condition.
Signed-off-by: Pan Xinhui <xinhuix.pan@intel.com> Cc: Yury Norov <yury.norov@gmail.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/printk.h: include pr_fmt in pr_debug_ratelimited
The other two implementations of pr_debug_ratelimited include pr_fmt,
along with every other pr_* function. But pr_debug_ratelimited forgot to
add it with the CONFIG_DYNAMIC_DEBUG implementation.
This patch unifies the behavior.
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit e0e817392b9a ("CRED: Add some configurable debugging [try #6]")
added the kdebug mechanism to this file back in 2009.
The kdebug macro calls no_printk which always evaluates arguments.
Most of the kdebug uses have an unnecessary call of
atomic_read(&cred->usage)
Make the kdebug macro do nothing by defining it with
do { if (0) no_printk(...); } while (0)
when not enabled.
$ size kernel/cred.o* (defconfig x86-64)
text data bss dec hex filename
2748 336 8 3092 c14 kernel/cred.o.new
2788 336 8 3132 c3c kernel/cred.o.old
Miscellanea:
o Neaten the #define kdebug macros while there
Signed-off-by: Joe Perches <joe@perches.com> Cc: David Howells <dhowells@redhat.com> Cc: James Morris <jmorris@namei.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Poison pointer values should be small enough to find a room in
non-mmap'able/hardly-mmap'able space. E.g. on x86 "poison pointer space"
is located starting from 0x0. Given unprivileged users cannot mmap
anything below mmap_min_addr, it should be safe to use poison pointers
lower than mmap_min_addr.
The current poison pointer values of LIST_POISON{1,2} might be too big for
mmap_min_addr values equal or less than 1 MB (common case, e.g. Ubuntu
uses only 0x10000). There is little point to use such a big value given
the "poison pointer space" below 1 MB is not yet exhausted. Changing it
to a smaller value solves the problem for small mmap_min_addr setups.
The values are suggested by Solar Designer:
http://www.openwall.com/lists/oss-security/2015/05/02/6
Signed-off-by: Vasily Kulikov <segoon@openwall.com> Cc: Solar Designer <solar@openwall.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Waiman Long [Wed, 9 Sep 2015 22:35:57 +0000 (15:35 -0700)]
proc: change proc_subdir_lock to a rwlock
The proc_subdir_lock spinlock is used to allow only one task to make
change to the proc directory structure as well as looking up information
in it. However, the information lookup part can actually be entered by
more than one task as the pde_get() and pde_put() reference count update
calls in the critical sections are atomic increment and decrement
respectively and so are safe with concurrent updates.
The x86 architecture has already used qrwlock which is fair and other
architectures like ARM are in the process of switching to qrwlock. So
unfairness shouldn't be a concern in that conversion.
This patch changed the proc_subdir_lock to a rwlock in order to enable
concurrent lookup. The following functions were modified to take a
write lock:
- proc_register()
- remove_proc_entry()
- remove_proc_subtree()
The following functions were modified to take a read lock:
- xlate_proc_name()
- proc_lookup_de()
- proc_readdir_de()
A parallel /proc filesystem search with the "find" command (1000 threads)
was run on a 4-socket Haswell-EX box (144 threads). Before the patch, the
parallel search took about 39s. After the patch, the parallel find took
only 25s, a saving of about 14s.
The micro-benchmark that I used was artificial, but it was used to
reproduce an exit hanging problem that I saw in real application. In
fact, only allow one task to do a lookup seems too limiting to me.
Signed-off-by: Waiman Long <Waiman.Long@hp.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Scott J Norton <scott.norton@hp.com> Cc: Douglas Hatch <doug.hatch@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
procfs: always expose /proc/<pid>/map_files/ and make it readable
Currently, /proc/<pid>/map_files/ is restricted to CAP_SYS_ADMIN, and is
only exposed if CONFIG_CHECKPOINT_RESTORE is set.
Each mapped file region gets a symlink in /proc/<pid>/map_files/
corresponding to the virtual address range at which it is mapped. The
symlinks work like the symlinks in /proc/<pid>/fd/, so you can follow them
to the backing file even if that backing file has been unlinked.
Currently, files which are mapped, unlinked, and closed are impossible to
stat() from userspace. Exposing /proc/<pid>/map_files/ closes this
functionality "hole".
Not being able to stat() such files makes noticing and explicitly
accounting for the space they use on the filesystem impossible. You can
work around this by summing up the space used by every file in the
filesystem and subtracting that total from what statfs() tells you, but
that obviously isn't great, and it becomes unworkable once your filesystem
becomes large enough.
This patch moves map_files/ out from behind CONFIG_CHECKPOINT_RESTORE, and
adjusts the permissions enforced on it as follows:
Remove the CAP_SYS_ADMIN restriction, leaving only the current
restriction requiring PTRACE_MODE_READ. The information made
available to userspace by these three functions is already
available in /proc/PID/maps with MODE_READ, so I don't see any
reason to limit them any further (see below for more detail).
* proc_map_files_follow_link()
This stub has been added, and requires that the user have
CAP_SYS_ADMIN in order to follow the links in map_files/,
since there was concern on LKML both about the potential for
bypassing permissions on ancestor directories in the path to
files pointed to, and about what happens with more exotic
memory mappings created by some drivers (ie dma-buf).
In older versions of this patch, I changed every permission check in
the four functions above to enforce MODE_ATTACH instead of MODE_READ.
This was an oversight on my part, and after revisiting the discussion
it seems that nobody was concerned about anything outside of what is
made possible by ->follow_link(). So in this version, I've left the
checks for PTRACE_MODE_READ as-is.
[akpm@linux-foundation.org: catch up with concurrent proc_pid_follow_link() changes] Signed-off-by: Calvin Owens <calvinowens@fb.com> Reviewed-by: Kees Cook <keescook@chromium.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Joe Perches <joe@perches.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
proc: add cond_resched to /proc/kpage* read/write loop
Reading/writing a /proc/kpage* file may take long on machines with a lot
of RAM installed.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Suggested-by: Andres Lagar-Cavilla <andreslc@google.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As noted by Minchan, a benefit of reading idle flag from /proc/kpageflags
is that one can easily filter dirty and/or unevictable pages while
estimating the size of unused memory.
Note that idle flag read from /proc/kpageflags may be stale in case the
page was accessed via a PTE, because it would be too costly to iterate
over all page mappings on each /proc/kpageflags read to provide an
up-to-date value. To make sure the flag is up-to-date one has to read
/sys/kernel/mm/page_idle/bitmap first.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Knowing the portion of memory that is not used by a certain application or
memory cgroup (idle memory) can be useful for partitioning the system
efficiently, e.g. by setting memory cgroup limits appropriately.
Currently, the only means to estimate the amount of idle memory provided
by the kernel is /proc/PID/{clear_refs,smaps}: the user can clear the
access bit for all pages mapped to a particular process by writing 1 to
clear_refs, wait for some time, and then count smaps:Referenced. However,
this method has two serious shortcomings:
- it does not count unmapped file pages
- it affects the reclaimer logic
To overcome these drawbacks, this patch introduces two new page flags,
Idle and Young, and a new sysfs file, /sys/kernel/mm/page_idle/bitmap.
A page's Idle flag can only be set from userspace by setting bit in
/sys/kernel/mm/page_idle/bitmap at the offset corresponding to the page,
and it is cleared whenever the page is accessed either through page tables
(it is cleared in page_referenced() in this case) or using the read(2)
system call (mark_page_accessed()). Thus by setting the Idle flag for
pages of a particular workload, which can be found e.g. by reading
/proc/PID/pagemap, waiting for some time to let the workload access its
working set, and then reading the bitmap file, one can estimate the amount
of pages that are not used by the workload.
The Young page flag is used to avoid interference with the memory
reclaimer. A page's Young flag is set whenever the Access bit of a page
table entry pointing to the page is cleared by writing to the bitmap file.
If page_referenced() is called on a Young page, it will add 1 to its
return value, therefore concealing the fact that the Access bit was
cleared.
Note, since there is no room for extra page flags on 32 bit, this feature
uses extended page flags when compiled on 32 bit.
[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: kpageidle requires an MMU]
[akpm@linux-foundation.org: decouple from page-flags rework] Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In the scope of the idle memory tracking feature, which is introduced by
the following patch, we need to clear the referenced/accessed bit not only
in primary, but also in secondary ptes. The latter is required in order
to estimate wss of KVM VMs. At the same time we want to avoid flushing
tlb, because it is quite expensive and it won't really affect the final
result.
Currently, there is no function for clearing pte young bit that would meet
our requirements, so this patch introduces one. To achieve that we have
to add a new mmu-notifier callback, clear_young, since there is no method
for testing-and-clearing a secondary pte w/o flushing tlb. The new method
is not mandatory and currently only implemented by KVM.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Acked-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/proc/kpagecgroup contains a 64-bit inode number of the memory cgroup each
page is charged to, indexed by PFN. Having this information is useful for
estimating a cgroup working set size.
The file is present if CONFIG_PROC_PAGE_MONITOR && CONFIG_MEMCG.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It is only used in mem_cgroup_try_charge, so fold it in and zap it.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hwpoison: use page_cgroup_ino for filtering by memcg
Hwpoison allows to filter pages by memory cgroup ino. Currently, it
calls try_get_mem_cgroup_from_page to obtain the cgroup from a page and
then its ino using cgroup_ino, but now we have a helper method for
that, page_cgroup_ino, so use it instead.
This patch also loosens the hwpoison memcg filter dependency rules - it
makes it depend on CONFIG_MEMCG instead of CONFIG_MEMCG_SWAP, because
hwpoison memcg filter does not require anything (nor it used to) from
CONFIG_MEMCG_SWAP side.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patchset introduces a new user API for tracking user memory pages
that have not been used for a given period of time. The purpose of this
is to provide the userspace with the means of tracking a workload's
working set, i.e. the set of pages that are actively used by the
workload. Knowing the working set size can be useful for partitioning the
system more efficiently, e.g. by tuning memory cgroup limits
appropriately, or for job placement within a compute cluster.
==== USE CASES ====
The unified cgroup hierarchy has memory.low and memory.high knobs, which
are defined as the low and high boundaries for the workload working set
size. However, the working set size of a workload may be unknown or
change in time. With this patch set, one can periodically estimate the
amount of memory unused by each cgroup and tune their memory.low and
memory.high parameters accordingly, therefore optimizing the overall
memory utilization.
Another use case is balancing workloads within a compute cluster. Knowing
how much memory is not really used by a workload unit may help take a more
optimal decision when considering migrating the unit to another node
within the cluster.
Also, as noted by Minchan, this would be useful for per-process reclaim
(https://lwn.net/Articles/545668/). With idle tracking, we could reclaim idle
pages only by smart user memory manager.
==== USER API ====
The user API consists of two new files:
* /sys/kernel/mm/page_idle/bitmap. This file implements a bitmap where each
bit corresponds to a page, indexed by PFN. When the bit is set, the
corresponding page is idle. A page is considered idle if it has not been
accessed since it was marked idle. To mark a page idle one should set the
bit corresponding to the page by writing to the file. A value written to the
file is OR-ed with the current bitmap value. Only user memory pages can be
marked idle, for other page types input is silently ignored. Writing to this
file beyond max PFN results in the ENXIO error. Only available when
CONFIG_IDLE_PAGE_TRACKING is set.
This file can be used to estimate the amount of pages that are not
used by a particular workload as follows:
1. mark all pages of interest idle by setting corresponding bits in the
/sys/kernel/mm/page_idle/bitmap
2. wait until the workload accesses its working set
3. read /sys/kernel/mm/page_idle/bitmap and count the number of bits set
* /proc/kpagecgroup. This file contains a 64-bit inode number of the
memory cgroup each page is charged to, indexed by PFN. Only available when
CONFIG_MEMCG is set.
This file can be used to find all pages (including unmapped file pages)
accounted to a particular cgroup. Using /sys/kernel/mm/page_idle/bitmap, one
can then estimate the cgroup working set size.
For an example of using these files for estimating the amount of unused
memory pages per each memory cgroup, please see the script attached
below.
==== REASONING ====
The reason to introduce the new user API instead of using
/proc/PID/{clear_refs,smaps} is that the latter has two serious
drawbacks:
- it does not count unmapped file pages
- it affects the reclaimer logic
The new API attempts to overcome them both. For more details on how it
is achieved, please see the comment to patch 6.
==== PATCHSET STRUCTURE ====
The patch set is organized as follows:
- patch 1 adds page_cgroup_ino() helper for the sake of
/proc/kpagecgroup and patches 2-3 do related cleanup
- patch 4 adds /proc/kpagecgroup, which reports cgroup ino each page is
charged to
- patch 5 introduces a new mmu notifier callback, clear_young, which is
a lightweight version of clear_flush_young; it is used in patch 6
- patch 6 implements the idle page tracking feature, including the
userspace API, /sys/kernel/mm/page_idle/bitmap
- patch 7 exports idle flag via /proc/kpageflags
==== SIMILAR WORKS ====
Originally, the patch for tracking idle memory was proposed back in 2011
by Michel Lespinasse (see http://lwn.net/Articles/459269/). The main
difference between Michel's patch and this one is that Michel implemented
a kernel space daemon for estimating idle memory size per cgroup while
this patch only provides the userspace with the minimal API for doing the
job, leaving the rest up to the userspace. However, they both share the
same idea of Idle/Young page flags to avoid affecting the reclaimer logic.
==== PERFORMANCE EVALUATION ====
SPECjvm2008 (https://www.spec.org/jvm2008/) was used to evaluate the
performance impact introduced by this patch set. Three runs were carried
out:
- base: kernel without the patch
- patched: patched kernel, the feature is not used
- patched-active: patched kernel, 1 minute-period daemon is used for
tracking idle memory
For tracking idle memory, idlememstat utility was used:
https://github.com/locker/idlememstat
for dir, subdirs, files in os.walk(CGROUP_MOUNT):
ino = os.stat(dir)[stat.ST_INO]
print dir + ": " + str(idlememsz.get(ino, 0) / 1024) + " kB"
==== END SCRIPT ====
This patch (of 8):
Add page_cgroup_ino() helper to memcg.
This function returns the inode number of the closest online ancestor of
the memory cgroup a page is charged to. It is required for exporting
information about which page is charged to which cgroup to userspace,
which will be introduced by a following patch.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Greg Thelen <gthelen@google.com> Cc: Michel Lespinasse <walken@google.com> Cc: David Rientjes <rientjes@google.com> Cc: Pavel Emelyanov <xemul@parallels.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jonathan Corbet <corbet@lwn.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / karo-tx-linux.git / log