Commit Graph

919 Commits

Author SHA1 Message Date
Greg Kroah-Hartman
071b028ed3 Merge 4.19.45 into android-4.19-q
Changes in 4.19.45
	locking/rwsem: Prevent decrement of reader count before increment
	x86/speculation/mds: Revert CPU buffer clear on double fault exit
	x86/speculation/mds: Improve CPU buffer clear documentation
	objtool: Fix function fallthrough detection
	arm64: dts: rockchip: Disable DCMDs on RK3399's eMMC controller.
	ARM: dts: exynos: Fix interrupt for shared EINTs on Exynos5260
	ARM: dts: exynos: Fix audio (microphone) routing on Odroid XU3
	mmc: sdhci-of-arasan: Add DTS property to disable DCMDs.
	ARM: exynos: Fix a leaked reference by adding missing of_node_put
	power: supply: axp288_charger: Fix unchecked return value
	power: supply: axp288_fuel_gauge: Add ACEPC T8 and T11 mini PCs to the blacklist
	arm64: mmap: Ensure file offset is treated as unsigned
	arm64: arch_timer: Ensure counter register reads occur with seqlock held
	arm64: compat: Reduce address limit
	arm64: Clear OSDLR_EL1 on CPU boot
	arm64: Save and restore OSDLR_EL1 across suspend/resume
	sched/x86: Save [ER]FLAGS on context switch
	crypto: crypto4xx - fix ctr-aes missing output IV
	crypto: crypto4xx - fix cfb and ofb "overran dst buffer" issues
	crypto: salsa20 - don't access already-freed walk.iv
	crypto: chacha20poly1305 - set cra_name correctly
	crypto: ccp - Do not free psp_master when PLATFORM_INIT fails
	crypto: vmx - fix copy-paste error in CTR mode
	crypto: skcipher - don't WARN on unprocessed data after slow walk step
	crypto: crct10dif-generic - fix use via crypto_shash_digest()
	crypto: x86/crct10dif-pcl - fix use via crypto_shash_digest()
	crypto: arm64/gcm-aes-ce - fix no-NEON fallback code
	crypto: gcm - fix incompatibility between "gcm" and "gcm_base"
	crypto: rockchip - update IV buffer to contain the next IV
	crypto: arm/aes-neonbs - don't access already-freed walk.iv
	crypto: arm64/aes-neonbs - don't access already-freed walk.iv
	mmc: core: Fix tag set memory leak
	ALSA: line6: toneport: Fix broken usage of timer for delayed execution
	ALSA: usb-audio: Fix a memory leak bug
	ALSA: hda/hdmi - Read the pin sense from register when repolling
	ALSA: hda/hdmi - Consider eld_valid when reporting jack event
	ALSA: hda/realtek - EAPD turn on later
	ALSA: hdea/realtek - Headset fixup for System76 Gazelle (gaze14)
	ASoC: max98090: Fix restore of DAPM Muxes
	ASoC: RT5677-SPI: Disable 16Bit SPI Transfers
	ASoC: fsl_esai: Fix missing break in switch statement
	ASoC: codec: hdac_hdmi add device_link to card device
	bpf, arm64: remove prefetch insn in xadd mapping
	crypto: ccree - remove special handling of chained sg
	crypto: ccree - fix mem leak on error path
	crypto: ccree - don't map MAC key on stack
	crypto: ccree - use correct internal state sizes for export
	crypto: ccree - don't map AEAD key and IV on stack
	crypto: ccree - pm resume first enable the source clk
	crypto: ccree - HOST_POWER_DOWN_EN should be the last CC access during suspend
	crypto: ccree - add function to handle cryptocell tee fips error
	crypto: ccree - handle tee fips error during power management resume
	mm/mincore.c: make mincore() more conservative
	mm/huge_memory: fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses
	mm/hugetlb.c: don't put_page in lock of hugetlb_lock
	hugetlb: use same fault hash key for shared and private mappings
	ocfs2: fix ocfs2 read inode data panic in ocfs2_iget
	userfaultfd: use RCU to free the task struct when fork fails
	ACPI: PM: Set enable_for_wake for wakeup GPEs during suspend-to-idle
	mfd: da9063: Fix OTP control register names to match datasheets for DA9063/63L
	mfd: max77620: Fix swapped FPS_PERIOD_MAX_US values
	mtd: spi-nor: intel-spi: Avoid crossing 4K address boundary on read/write
	tty: vt.c: Fix TIOCL_BLANKSCREEN console blanking if blankinterval == 0
	tty/vt: fix write/write race in ioctl(KDSKBSENT) handler
	jbd2: check superblock mapped prior to committing
	ext4: make sanity check in mballoc more strict
	ext4: ignore e_value_offs for xattrs with value-in-ea-inode
	ext4: avoid drop reference to iloc.bh twice
	ext4: fix use-after-free race with debug_want_extra_isize
	ext4: actually request zeroing of inode table after grow
	ext4: fix ext4_show_options for file systems w/o journal
	btrfs: Check the first key and level for cached extent buffer
	btrfs: Correctly free extent buffer in case btree_read_extent_buffer_pages fails
	btrfs: Honour FITRIM range constraints during free space trim
	Btrfs: send, flush dellaloc in order to avoid data loss
	Btrfs: do not start a transaction during fiemap
	Btrfs: do not start a transaction at iterate_extent_inodes()
	bcache: fix a race between cache register and cacheset unregister
	bcache: never set KEY_PTRS of journal key to 0 in journal_reclaim()
	ipmi:ssif: compare block number correctly for multi-part return messages
	crypto: ccm - fix incompatibility between "ccm" and "ccm_base"
	fs/writeback.c: use rcu_barrier() to wait for inflight wb switches going into workqueue when umount
	tty: Don't force RISCV SBI console as preferred console
	ext4: zero out the unused memory region in the extent tree block
	ext4: fix data corruption caused by overlapping unaligned and aligned IO
	ext4: fix use-after-free in dx_release()
	ext4: avoid panic during forced reboot due to aborted journal
	ALSA: hda/realtek - Corrected fixup for System76 Gazelle (gaze14)
	ALSA: hda/realtek - Fixup headphone noise via runtime suspend
	ALSA: hda/realtek - Fix for Lenovo B50-70 inverted internal microphone bug
	jbd2: fix potential double free
	KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes
	KVM: lapic: Busy wait for timer to expire when using hv_timer
	kbuild: turn auto.conf.cmd into a mandatory include file
	xen/pvh: set xen_domain_type to HVM in xen_pvh_init
	libnvdimm/namespace: Fix label tracking error
	iov_iter: optimize page_copy_sane()
	pstore: Centralize init/exit routines
	pstore: Allocate compression during late_initcall()
	pstore: Refactor compression initialization
	ext4: fix compile error when using BUFFER_TRACE
	ext4: don't update s_rev_level if not required
	Linux 4.19.45

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-05-22 08:01:49 +02:00
Greg Kroah-Hartman
50f91435a2 Merge 4.19.45 into android-4.19
Changes in 4.19.45
	locking/rwsem: Prevent decrement of reader count before increment
	x86/speculation/mds: Revert CPU buffer clear on double fault exit
	x86/speculation/mds: Improve CPU buffer clear documentation
	objtool: Fix function fallthrough detection
	arm64: dts: rockchip: Disable DCMDs on RK3399's eMMC controller.
	ARM: dts: exynos: Fix interrupt for shared EINTs on Exynos5260
	ARM: dts: exynos: Fix audio (microphone) routing on Odroid XU3
	mmc: sdhci-of-arasan: Add DTS property to disable DCMDs.
	ARM: exynos: Fix a leaked reference by adding missing of_node_put
	power: supply: axp288_charger: Fix unchecked return value
	power: supply: axp288_fuel_gauge: Add ACEPC T8 and T11 mini PCs to the blacklist
	arm64: mmap: Ensure file offset is treated as unsigned
	arm64: arch_timer: Ensure counter register reads occur with seqlock held
	arm64: compat: Reduce address limit
	arm64: Clear OSDLR_EL1 on CPU boot
	arm64: Save and restore OSDLR_EL1 across suspend/resume
	sched/x86: Save [ER]FLAGS on context switch
	crypto: crypto4xx - fix ctr-aes missing output IV
	crypto: crypto4xx - fix cfb and ofb "overran dst buffer" issues
	crypto: salsa20 - don't access already-freed walk.iv
	crypto: chacha20poly1305 - set cra_name correctly
	crypto: ccp - Do not free psp_master when PLATFORM_INIT fails
	crypto: vmx - fix copy-paste error in CTR mode
	crypto: skcipher - don't WARN on unprocessed data after slow walk step
	crypto: crct10dif-generic - fix use via crypto_shash_digest()
	crypto: x86/crct10dif-pcl - fix use via crypto_shash_digest()
	crypto: arm64/gcm-aes-ce - fix no-NEON fallback code
	crypto: gcm - fix incompatibility between "gcm" and "gcm_base"
	crypto: rockchip - update IV buffer to contain the next IV
	crypto: arm/aes-neonbs - don't access already-freed walk.iv
	crypto: arm64/aes-neonbs - don't access already-freed walk.iv
	mmc: core: Fix tag set memory leak
	ALSA: line6: toneport: Fix broken usage of timer for delayed execution
	ALSA: usb-audio: Fix a memory leak bug
	ALSA: hda/hdmi - Read the pin sense from register when repolling
	ALSA: hda/hdmi - Consider eld_valid when reporting jack event
	ALSA: hda/realtek - EAPD turn on later
	ALSA: hdea/realtek - Headset fixup for System76 Gazelle (gaze14)
	ASoC: max98090: Fix restore of DAPM Muxes
	ASoC: RT5677-SPI: Disable 16Bit SPI Transfers
	ASoC: fsl_esai: Fix missing break in switch statement
	ASoC: codec: hdac_hdmi add device_link to card device
	bpf, arm64: remove prefetch insn in xadd mapping
	crypto: ccree - remove special handling of chained sg
	crypto: ccree - fix mem leak on error path
	crypto: ccree - don't map MAC key on stack
	crypto: ccree - use correct internal state sizes for export
	crypto: ccree - don't map AEAD key and IV on stack
	crypto: ccree - pm resume first enable the source clk
	crypto: ccree - HOST_POWER_DOWN_EN should be the last CC access during suspend
	crypto: ccree - add function to handle cryptocell tee fips error
	crypto: ccree - handle tee fips error during power management resume
	mm/mincore.c: make mincore() more conservative
	mm/huge_memory: fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses
	mm/hugetlb.c: don't put_page in lock of hugetlb_lock
	hugetlb: use same fault hash key for shared and private mappings
	ocfs2: fix ocfs2 read inode data panic in ocfs2_iget
	userfaultfd: use RCU to free the task struct when fork fails
	ACPI: PM: Set enable_for_wake for wakeup GPEs during suspend-to-idle
	mfd: da9063: Fix OTP control register names to match datasheets for DA9063/63L
	mfd: max77620: Fix swapped FPS_PERIOD_MAX_US values
	mtd: spi-nor: intel-spi: Avoid crossing 4K address boundary on read/write
	tty: vt.c: Fix TIOCL_BLANKSCREEN console blanking if blankinterval == 0
	tty/vt: fix write/write race in ioctl(KDSKBSENT) handler
	jbd2: check superblock mapped prior to committing
	ext4: make sanity check in mballoc more strict
	ext4: ignore e_value_offs for xattrs with value-in-ea-inode
	ext4: avoid drop reference to iloc.bh twice
	ext4: fix use-after-free race with debug_want_extra_isize
	ext4: actually request zeroing of inode table after grow
	ext4: fix ext4_show_options for file systems w/o journal
	btrfs: Check the first key and level for cached extent buffer
	btrfs: Correctly free extent buffer in case btree_read_extent_buffer_pages fails
	btrfs: Honour FITRIM range constraints during free space trim
	Btrfs: send, flush dellaloc in order to avoid data loss
	Btrfs: do not start a transaction during fiemap
	Btrfs: do not start a transaction at iterate_extent_inodes()
	bcache: fix a race between cache register and cacheset unregister
	bcache: never set KEY_PTRS of journal key to 0 in journal_reclaim()
	ipmi:ssif: compare block number correctly for multi-part return messages
	crypto: ccm - fix incompatibility between "ccm" and "ccm_base"
	fs/writeback.c: use rcu_barrier() to wait for inflight wb switches going into workqueue when umount
	tty: Don't force RISCV SBI console as preferred console
	ext4: zero out the unused memory region in the extent tree block
	ext4: fix data corruption caused by overlapping unaligned and aligned IO
	ext4: fix use-after-free in dx_release()
	ext4: avoid panic during forced reboot due to aborted journal
	ALSA: hda/realtek - Corrected fixup for System76 Gazelle (gaze14)
	ALSA: hda/realtek - Fixup headphone noise via runtime suspend
	ALSA: hda/realtek - Fix for Lenovo B50-70 inverted internal microphone bug
	jbd2: fix potential double free
	KVM: x86: Skip EFER vs. guest CPUID checks for host-initiated writes
	KVM: lapic: Busy wait for timer to expire when using hv_timer
	kbuild: turn auto.conf.cmd into a mandatory include file
	xen/pvh: set xen_domain_type to HVM in xen_pvh_init
	libnvdimm/namespace: Fix label tracking error
	iov_iter: optimize page_copy_sane()
	pstore: Centralize init/exit routines
	pstore: Allocate compression during late_initcall()
	pstore: Refactor compression initialization
	ext4: fix compile error when using BUFFER_TRACE
	ext4: don't update s_rev_level if not required
	Linux 4.19.45

Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2019-05-22 08:00:39 +02:00
Andrea Arcangeli
8bae439855 userfaultfd: use RCU to free the task struct when fork fails
commit c3f3ce049f7d97cc7ec9c01cb51d9ec74e0f37c2 upstream.

The task structure is freed while get_mem_cgroup_from_mm() holds
rcu_read_lock() and dereferences mm->owner.

  get_mem_cgroup_from_mm()                failing fork()
  ----                                    ---
  task = mm->owner
                                          mm->owner = NULL;
                                          free(task)
  if (task) *task; /* use after free */

The fix consists in freeing the task with RCU also in the fork failure
case, exactly like it always happens for the regular exit(2) path.  That
is enough to make the rcu_read_lock hold in get_mem_cgroup_from_mm()
(left side above) effective to avoid a use after free when dereferencing
the task structure.

An alternate possible fix would be to defer the delivery of the
userfaultfd contexts to the monitor until after fork() is guaranteed to
succeed.  Such a change would require more changes because it would
create a strict ordering dependency where the uffd methods would need to
be called beyond the last potentially failing branch in order to be
safe.  This solution as opposed only adds the dependency to common code
to set mm->owner to NULL and to free the task struct that was pointed by
mm->owner with RCU, if fork ends up failing.  The userfaultfd methods
can still be called anywhere during the fork runtime and the monitor
will keep discarding orphaned "mm" coming from failed forks in userland.

This race condition couldn't trigger if CONFIG_MEMCG was set =n at build
time.

[aarcange@redhat.com: improve changelog, reduce #ifdefs per Michal]
  Link: http://lkml.kernel.org/r/20190429035752.4508-1-aarcange@redhat.com
Link: http://lkml.kernel.org/r/20190325225636.11635-2-aarcange@redhat.com
Fixes: 893e26e61d ("userfaultfd: non-cooperative: Add fork() event")
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Tested-by: zhong jiang <zhongjiang@huawei.com>
Reported-by: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Jason Gunthorpe <jgg@mellanox.com>
Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: zhong jiang <zhongjiang@huawei.com>
Cc: syzbot+cbb52e396df3e565ab02@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-22 07:37:41 +02:00
Laurent Dufour
0c8a35f8dd mm: protect against PTE changes done by dup_mmap()
Vinayak Menon and Ganesh Mahendran reported that the following scenario may
lead to thread being blocked due to data corruption:

    CPU 1                   CPU 2                    CPU 3
    Process 1,              Process 1,               Process 1,
    Thread A                Thread B                 Thread C

    while (1) {             while (1) {              while(1) {
    pthread_mutex_lock(l)   pthread_mutex_lock(l)    fork
    pthread_mutex_unlock(l) pthread_mutex_unlock(l)  }
    }                       }

In the details this happens because :

    CPU 1                CPU 2                       CPU 3
    fork()
    copy_pte_range()
      set PTE rdonly
    got to next VMA...
     .                   PTE is seen rdonly          PTE still writable
     .                   thread is writing to page
     .                   -> page fault
     .                     copy the page             Thread writes to page
     .                      .                        -> no page fault
     .                     update the PTE
     .                     flush TLB for that PTE
   flush TLB                                        PTE are now rdonly

So the write done by the CPU 3 is interfering with the page copy operation
done by CPU 2, leading to the data corruption.

To avoid this we mark all the VMA involved in the COW mechanism as changing
by calling vm_write_begin(). This ensures that the speculative page fault
handler will not try to handle a fault on these pages.
The marker is set until the TLB is flushed, ensuring that all the CPUs will
now see the PTE as not writable.
Once the TLB is flush, the marker is removed by calling vm_write_end().

The variable last is used to keep tracked of the latest VMA marked to
handle the error path where part of the VMA may have been marked.

Change-Id: I3fe07109e27d8f77c9b435053567fe5c287703aa
Reported-by: Ganesh Mahendran <opensource.ganesh@gmail.com>
Reported-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
Link: https://www.spinics.net/lists/linux-mm/msg171207.html
Patch-mainline: linux-mm@ Fri, 18 Jan 2019 17:24:16
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
2019-04-01 21:57:33 -07:00
Laurent Dufour
3f31f748a8 mm: protect mm_rb tree with a rwlock
This change is inspired by the Peter's proposal patch [1] which was
protecting the VMA using SRCU. Unfortunately, SRCU is not scaling well in
that particular case, and it is introducing major performance degradation
due to excessive scheduling operations.

To allow access to the mm_rb tree without grabbing the mmap_sem, this patch
is protecting it access using a rwlock.  As the mm_rb tree is a O(log n)
search it is safe to protect it using such a lock.  The VMA cache is not
protected by the new rwlock and it should not be used without holding the
mmap_sem.

To allow the picked VMA structure to be used once the rwlock is released, a
use count is added to the VMA structure. When the VMA is allocated it is
set to 1.  Each time the VMA is picked with the rwlock held its use count
is incremented. Each time the VMA is released it is decremented. When the
use count hits zero, this means that the VMA is no more used and should be
freed.

This patch is preparing for 2 kind of VMA access :
 - as usual, under the control of the mmap_sem,
 - without holding the mmap_sem for the speculative page fault handler.

Access done under the control the mmap_sem doesn't require to grab the
rwlock to protect read access to the mm_rb tree, but access in write must
be done under the protection of the rwlock too. This affects inserting and
removing of elements in the RB tree.

The patch is introducing 2 new functions:
 - vma_get() to find a VMA based on an address by holding the new rwlock.
 - vma_put() to release the VMA when its no more used.
These services are designed to be used when access are made to the RB tree
without holding the mmap_sem.

When a VMA is removed from the RB tree, its vma->vm_rb field is cleared and
we rely on the WMB done when releasing the rwlock to serialize the write
with the RMB done in a later patch to check for the VMA's validity.

When free_vma is called, the file associated with the VMA is closed
immediately, but the policy and the file structure remained in used until
the VMA's use count reach 0, which may happens later when exiting an
in progress speculative page fault.

[1] https://patchwork.kernel.org/patch/5108281/

Change-Id: I9ecc922b8efa4b28975cc6a8e9531284c24ac14e
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Patch-mainline: linux-mm @ Tue, 17 Apr 2018 16:33:23
[vinmenon@codeaurora.org: fix the return of put_vma]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
2019-04-01 12:48:55 +05:30
Laurent Dufour
ead04c98fd mm: introduce INIT_VMA()
Some VMA struct fields need to be initialized once the VMA structure is
allocated.
Currently this only concerns anon_vma_chain field but some other will be
added to support the speculative page fault.

Instead of spreading the initialization calls all over the code, let's
introduce a dedicated inline function.

Change-Id: I9f6b29dc74055354318b548e2b6b22c37d4c61bb
Signed-off-by: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Patch-mainline: linux-mm @ Tue, 17 Apr 2018 16:33:13
[vinmenon@codeaurora.org: trivial merge conflict fixes]
Signed-off-by: Vinayak Menon <vinmenon@codeaurora.org>
[charante@codeaurora.org: merge conflict fixes]
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>
2019-03-29 03:08:28 -07:00
Johannes Weiner
e550f94252 UPSTREAM: psi: pressure stall information for CPU, memory, and IO
When systems are overcommitted and resources become contended, it's hard
to tell exactly the impact this has on workload productivity, or how close
the system is to lockups and OOM kills.  In particular, when machines work
multiple jobs concurrently, the impact of overcommit in terms of latency
and throughput on the individual job can be enormous.

In order to maximize hardware utilization without sacrificing individual
job health or risk complete machine lockups, this patch implements a way
to quantify resource pressure in the system.

A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that
expose the percentage of time the system is stalled on CPU, memory, or IO,
respectively.  Stall states are aggregate versions of the per-task delay
accounting delays:

       cpu: some tasks are runnable but not executing on a CPU
       memory: tasks are reclaiming, or waiting for swapin or thrashing cache
       io: tasks are waiting for io completions

These percentages of walltime can be thought of as pressure percentages,
and they give a general sense of system health and productivity loss
incurred by resource overcommit.  They can also indicate when the system
is approaching lockup scenarios and OOMs.

To do this, psi keeps track of the task states associated with each CPU
and samples the time they spend in stall states.  Every 2 seconds, the
samples are averaged across CPUs - weighted by the CPUs' non-idle time to
eliminate artifacts from unused CPUs - and translated into percentages of
walltime.  A running average of those percentages is maintained over 10s,
1m, and 5m periods (similar to the loadaverage).

[hannes@cmpxchg.org: doc fixlet, per Randy]
  Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org
[hannes@cmpxchg.org: code optimization]
  Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org
[hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter]
  Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org
[hannes@cmpxchg.org: fix build]
  Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org
Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Drake <drake@endlessm.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <jweiner@fb.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Enderborg <peter.enderborg@sony.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

(cherry picked from commit eb414681d5a07d28d2ff90dc05f69ec6b232ebd2)

Bug: 127712811
Test: lmkd in PSI mode
Change-Id: Id00d23c977169b0c4636d92016fc1fee0274be05
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
2019-03-21 16:25:27 -07:00
Johannes Weiner
25f0c86db1 psi: pressure stall information for CPU, memory, and IO
When systems are overcommitted and resources become contended, it's hard
to tell exactly the impact this has on workload productivity, or how close
the system is to lockups and OOM kills.  In particular, when machines work
multiple jobs concurrently, the impact of overcommit in terms of latency
and throughput on the individual job can be enormous.

In order to maximize hardware utilization without sacrificing individual
job health or risk complete machine lockups, this patch implements a way
to quantify resource pressure in the system.

A kernel built with CONFIG_PSI=y creates files in /proc/pressure/ that
expose the percentage of time the system is stalled on CPU, memory, or IO,
respectively.  Stall states are aggregate versions of the per-task delay
accounting delays:

       cpu: some tasks are runnable but not executing on a CPU
       memory: tasks are reclaiming, or waiting for swapin or thrashing cache
       io: tasks are waiting for io completions

These percentages of walltime can be thought of as pressure percentages,
and they give a general sense of system health and productivity loss
incurred by resource overcommit.  They can also indicate when the system
is approaching lockup scenarios and OOMs.

To do this, psi keeps track of the task states associated with each CPU
and samples the time they spend in stall states.  Every 2 seconds, the
samples are averaged across CPUs - weighted by the CPUs' non-idle time to
eliminate artifacts from unused CPUs - and translated into percentages of
walltime.  A running average of those percentages is maintained over 10s,
1m, and 5m periods (similar to the loadaverage).

[hannes@cmpxchg.org: doc fixlet, per Randy]
  Link: http://lkml.kernel.org/r/20180828205625.GA14030@cmpxchg.org
[hannes@cmpxchg.org: code optimization]
  Link: http://lkml.kernel.org/r/20180907175015.GA8479@cmpxchg.org
[hannes@cmpxchg.org: rename psi_clock() to psi_update_work(), per Peter]
  Link: http://lkml.kernel.org/r/20180907145404.GB11088@cmpxchg.org
[hannes@cmpxchg.org: fix build]
  Link: http://lkml.kernel.org/r/20180913014222.GA2370@cmpxchg.org
Link: http://lkml.kernel.org/r/20180828172258.3185-9-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Daniel Drake <drake@endlessm.com>
Tested-by: Suren Baghdasaryan <surenb@google.com>
Cc: Christopher Lameter <cl@linux.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <jweiner@fb.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Enderborg <peter.enderborg@sony.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Vinayak Menon <vinmenon@codeaurora.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Change-Id: Ic4b6fddb7013719ffcba5d68abfda87ada90715a
Git-commit: eb414681d5a07d28d2ff90dc05f69ec6b232ebd2
Git-repo: https://source.codeaurora.org/quic/la/kernel/msm-4.19
[pdaly@codeaurora.org: Move PF_MEMSTALL flag]
Signed-off-by: Patrick Daly <pdaly@codeaurora.org>
2019-03-08 19:33:14 -08:00
Connor O'Brien
406d53f0c7 ANDROID: cpufreq: track per-task time in state
Add time in state data to task structs, and create
/proc/<pid>/time_in_state files to show how long each individual task
has run at each frequency.
Create a CONFIG_CPU_FREQ_TIMES option to enable/disable this tracking.

Bug: 72339335
Bug: 127641090
Test: Read /proc/<pid>/time_in_state
Change-Id: Ia6456754f4cb1e83b2bc35efa8fbe9f8696febc8
Signed-off-by: Connor O'Brien <connoro@google.com>
[astrachan: Folded the following changes into this patch:
            a6d3de6a7fba ("ANDROID: Reduce use of #ifdef CONFIG_CPU_FREQ_TIMES")
            b89ada5d9c09 ("ANDROID: Fix massive cpufreq_times memory leaks")]
Signed-off-by: Alistair Strachan <astrachan@google.com>
2019-03-06 15:57:25 +00:00
Ivaylo Georgiev
ffb1bfc29b Merge android-4.19.15 (caf5433) into msm-4.19
* refs/heads/tmp-caf5433:
  Linux 4.19.15
  bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
  drm/amd/display: Fix unintialized max_bpc state values
  drm/rockchip: psr: do not dereference encoder before it is null checked.
  drm/vc4: Set ->is_yuv to false when num_planes == 1
  drm/nouveau/drm/nouveau: Check rc from drm_dp_mst_topology_mgr_resume()
  lib: fix build failure in CONFIG_DEBUG_VIRTUAL test
  of: __of_detach_node() - remove node from phandle cache
  of: of_node_get()/of_node_put() nodes held in phandle cache
  power: supply: olpc_battery: correct the temperature units
  intel_th: msu: Fix an off-by-one in attribute store
  genwqe: Fix size check
  drivers/perf: hisi: Fixup one DDRC PMU register offset
  video: fbdev: pxafb: Fix "WARNING: invalid free of devm_ allocated data"
  ceph: don't update importing cap's mseq when handing cap export
  sched/fair: Fix infinite loop in update_blocked_averages() by reverting a9e7f6544b
  iommu/vt-d: Handle domain agaw being less than iommu agaw
  RDMA/srpt: Fix a use-after-free in the channel release code
  rxe: fix error completion wr_id and qp_num
  9p/net: put a lower bound on msize
  iio: dac: ad5686: fix bit shift read register
  powerpc/tm: Set MSR[TS] just prior to recheckpoint
  Revert "powerpc/tm: Unset MSR[TS] if not recheckpointing"
  leds: pwm: silently error out on EPROBE_DEFER
  arm64: relocatable: fix inconsistencies in linker script and options
  arm64: drop linker script hack to hide __efistub_ symbols
  nfsd4: zero-length WRITE should succeed
  lockd: Show pid of lockd for remote locks
  PCI / PM: Allow runtime PM without callback functions
  selinux: policydb - fix byte order and alignment issues
  b43: Fix error in cordic routine
  gfs2: Fix loop in gfs2_rbm_find
  gfs2: Get rid of potential double-freeing in gfs2_create_inode
  dlm: memory leaks on error path in dlm_user_request()
  dlm: lost put_lkb on error path in receive_convert() and receive_unlock()
  dlm: possible memory leak on error path in create_lkb()
  dlm: fixed memory leaks after failed ls_remove_names allocation
  block: mq-deadline: Fix write completion handling
  block: deactivate blk_stat timer in wbt_disable_default()
  Fix failure path in alloc_pid()
  driver core: Add missing dev->bus->need_parent_lock checks
  srcu: Lock srcu_data structure in srcu_gp_start()
  ALSA: usb-audio: Always check descriptor sizes in parser code
  ALSA: usb-audio: Fix an out-of-bound read in create_composite_quirks
  ALSA: usb-audio: Check mixer unit descriptors more strictly
  ALSA: usb-audio: Avoid access before bLength check in build_audio_procunit()
  ALSA: cs46xx: Potential NULL dereference in probe
  media: cx23885: only reset DMA on problematic CPUs
  mt76x0: init hw capabilities
  dma-direct: do not include SME mask in the DMA supported check
  raid6/ppc: Fix build for clang
  powerpc/boot: Set target when cross-compiling for clang
  Makefile: Export clang toolchain variables
  kbuild: consolidate Clang compiler flags
  kbuild: add -no-integrated-as Clang option unconditionally
  powerpc: Disable -Wbuiltin-requires-header when setjmp is used
  powerpc: avoid -mno-sched-epilog on GCC 4.9 and newer
  powerpc: consolidate -mno-sched-epilog into FTRACE flags
  powerpc: remove old GCC version checks
  sunrpc: use SVC_NET() in svcauth_gss_* functions
  sunrpc: fix cache_head leak due to queued request
  memcg, oom: notify on oom killer invocation from the charge path
  mm, swap: fix swapoff with KSM pages
  mm, hmm: mark hmm_devmem_{add, add_resource} EXPORT_SYMBOL_GPL
  mm, hmm: use devm semantics for hmm_devmem_{add, remove}
  mm, devm_memremap_pages: add MEMORY_DEVICE_PRIVATE support
  mm, devm_memremap_pages: fix shutdown handling
  mm, devm_memremap_pages: kill mapping "System RAM" support
  mm, devm_memremap_pages: mark devm_memremap_pages() EXPORT_SYMBOL_GPL
  hwpoison, memory_hotplug: allow hwpoisoned pages to be offlined
  zram: fix double free backing device
  fork: record start_time late
  scsi: lpfc: do not set queue->page_count to 0 if pc_sli4_params.wqpcnt is invalid
  scsi: zfcp: fix posting too many status read buffers leading to adapter shutdown
  auxdisplay: charlcd: fix x/y command parsing
  serial/sunsu: fix refcount leak
  qmi_wwan: Fix qmap header retrieval in qmimux_rx_fixup
  net: netxen: fix a missing check and an uninitialized use
  Input: synaptics - enable SMBus for HP EliteBook 840 G4
  gpio: mvebu: only fail on missing clk if pwm is actually to be used
  lan743x: Remove MAC Reset from initialization
  virtio: fix test build after uio.h change
  m68k: Fix memblock-related crashes
  kbuild: fix false positive warning/error about missing libelf
  mac80211: free skb fraglist before freeing the skb
  nl80211: fix memory leak if validate_pae_over_nl80211() fails
  vxge: ensure data0 is initialized in when fetching firmware version information
  lan78xx: Resolve issue with changing MAC address
  lan743x: Expand phy search for LAN7431
  net: macb: add missing barriers when reading descriptors
  net: macb: fix dropped RX frames due to a race
  net: macb: fix random memory corruption on RX with 64-bit DMA
  qed: Fix an error code qed_ll2_start_xmit()
  SUNRPC: Fix a race with XPRT_CONNECTING
  mac80211: fix a kernel panic when TXing after TXQ teardown
  net: hns: Fix ping failed when use net bridge and send multicast
  net: hns: Add mac pcs config when enable|disable mac
  net: hns: Fix ntuple-filters status error.
  net: hns: Avoid net reset caused by pause frames storm
  net: hns: Free irq when exit from abnormal branch
  net: hns: Clean rx fbd when ae stopped.
  net: hns: Fixed bug that netdev was opened twice
  net: hns: Some registers use wrong address according to the datasheet.
  net: hns: All ports can not work when insmod hns ko after rmmod.
  net: hns: Incorrect offset address used for some registers.
  w90p910_ether: remove incorrect __init annotation
  net/tls: Init routines in create_ctx
  drivers: net: xgene: Remove unnecessary forward declarations
  x86, hyperv: remove PCI dependency
  mt76: fix potential NULL pointer dereference in mt76_stop_tx_queues
  scsi: target: iscsi: cxgbit: add missing spin_lock_init()
  scsi: target: iscsi: cxgbit: fix csk leak
  bnx2x: Send update-svid ramrod with retry/poll flags enabled
  bnx2x: Remove configured vlans as part of unload sequence.
  bnx2x: Clear fip MAC when fcoe offload support is disabled
  netfilter: nf_conncount: use rb_link_node_rcu() instead of rb_link_node()
  netfilter: nat: can't use dst_hold on noref dst
  netfilter: ipset: do not call ipset_nest_end after nla_nest_cancel
  ixgbe: Fix race when the VF driver does a reset
  i40e: fix mac filter delete when setting mac address
  x86/dump_pagetables: Fix LDT remap address marker
  x86/mm: Fix guard hole handling
  ieee802154: ca8210: fix possible u8 overflow in ca8210_rx_done
  ibmvnic: Fix non-atomic memory allocation in IRQ context
  ibmvnic: Convert reset work item mutex to spin lock
  Input: synaptics - enable RMI on ThinkPad T560
  Input: omap-keypad - fix idle configuration to not block SoC idle states
  scsi: bnx2fc: Fix NULL dereference in error handling
  Revert "scsi: qla2xxx: Fix NVMe Target discovery"
  netfilter: seqadj: re-load tcp header pointer after possible head reallocation
  netfilter: nf_tables: fix suspicious RCU usage in nft_chain_stats_replace()
  ieee802154: hwsim: fix off-by-one in parse nested
  xfrm: Fix NULL pointer dereference in xfrm_input when skb_dst_force clears the dst_entry.
  xfrm: Fix bucket count reported to userspace
  xfrm: Fix error return code in xfrm_output_one()
  checkstack.pl: fix for aarch64
  IB/core: Fix oops in netdev_next_upper_dev_rcu()
  drm/amdgpu: Fix DEBUG_LOCKS_WARN_ON(depth <= 0) in amdgpu_ctx.lock
  powerpc/mm: Fallback to RAM if the altmap is unusable
  Input: restore EV_ABS ABS_RESERVED
  IB/mlx5: Block DEVX umem from the non applicable cases
  ARM: dts: imx7d-nitrogen7: Fix the description of the Wifi clock
  ARM: imx: update the cpu power up timing setting on i.mx6sx
  ARM: dts: imx7d-pico: Describe the Wifi clock
  HID: ite: Add USB id match for another ITE based keyboard rfkill key quirk
  powerpc/mm: Fix linux page tables build with some configs
  powerpc: Fix COFF zImage booting on old powermacs
  arm64: dts: mt7622: fix no more console output on rfb1
  pinctrl: meson: fix pull enable register calculation
  ARM: dts: sun8i: a83t: bananapi-m3: increase vcc-pd voltage to 3.3V
  f2fs: don't access node/meta inode mapping after iput
  f2fs: wait on atomic writes to count F2FS_CP_WB_DATA
  f2fs: sanity check of xattr entry size
  f2fs: fix use-after-free issue when accessing sbi->stat_info
  f2fs: check PageWriteback flag for ordered case
  f2fs: fix validation of the block count in sanity_check_raw_super
  f2fs: fix missing unlock(sbi->gc_mutex)
  f2fs: fix to dirty inode synchronously
  f2fs: clean up structure extent_node
  f2fs: fix block address for __check_sit_bitmap
  f2fs: fix sbi->extent_list corruption issue
  f2fs: clean up checkpoint flow
  f2fs: flush stale issued discard candidates
  f2fs: correct wrong spelling, issing_*
  f2fs: use kvmalloc, if kmalloc is failed
  f2fs: remove redundant comment of unused wio_mutex
  f2fs: fix to reorder set_page_dirty and wait_on_page_writeback
  f2fs: clear PG_writeback if IPU failed
  f2fs: add an ioctl() to explicitly trigger fsck later
  f2fs: avoid frequent costly fsck triggers
  f2fs: fix m_may_create to make OPU DIO write correctly
  f2fs: fix to update new block address correctly for OPU
  f2fs: adjust trace print in f2fs_get_victim() to cover all paths
  f2fs: fix to allow node segment for GC by ioctl path
  f2fs: make "f2fs_fault_name[]" const char *
  f2fs: read page index before freeing
  f2fs: fix wrong return value of f2fs_acl_create
  f2fs: avoid build warn of fall_through
  f2fs: fix race between write_checkpoint and write_begin
  f2fs: check memory boundary by insane namelen
  f2fs: only flush the single temp bio cache which owns the target page
  f2fs: fix out-place-update DIO write
  f2fs: fix to be aware discard/preflush/dio command in is_idle()
  f2fs: add to account direct IO
  f2fs: move dir data flush to write checkpoint process
  f2fs: Change to use DEFINE_SHOW_ATTRIBUTE macro
  f2fs: change segment to section in f2fs_ioc_gc_range
  f2fs: export migration_granularity sysfs entry
  f2fs: support subsectional garbage collection
  f2fs: introduce __is_large_section() for cleanup
  f2fs: clean up f2fs_sb_has_##feature_name
  f2fs: remove codes of unused wio_mutex
  f2fs: fix count of seg_freed to make sec_freed correct
  f2fs: fix to account preflush command for noflush_merge mode
  f2fs: avoid GC causing encrypted file corrupted

Conflicts:
	mm/memory_hotplug.c

Change-Id: I26d2fbdddfa882fe9aae568a84a9269725ffb5ea
Signed-off-by: Ivaylo Georgiev <irgeorgiev@codeaurora.org>
2019-02-27 02:23:14 -08:00
David Herrmann
bc999b5099 fork: record start_time late
commit 7b55851367136b1efd84d98fea81ba57a98304cf upstream.

This changes the fork(2) syscall to record the process start_time after
initializing the basic task structure but still before making the new
process visible to user-space.

Technically, we could record the start_time anytime during fork(2).  But
this might lead to scenarios where a start_time is recorded long before
a process becomes visible to user-space.  For instance, with
userfaultfd(2) and TLS, user-space can delay the execution of fork(2)
for an indefinite amount of time (and will, if this causes network
access, or similar).

By recording the start_time late, it much closer reflects the point in
time where the process becomes live and can be observed by other
processes.

Lastly, this makes it much harder for user-space to predict and control
the start_time they get assigned.  Previously, user-space could fork a
process and stall it in copy_thread_tls() before its pid is allocated,
but after its start_time is recorded.  This can be misused to later-on
cycle through PIDs and resume the stalled fork(2) yielding a process
that has the same pid and start_time as a process that existed before.
This can be used to circumvent security systems that identify processes
by their pid+start_time combination.

Even though user-space was always aware that start_time recording is
flaky (but several projects are known to still rely on start_time-based
identification), changing the start_time to be recorded late will help
mitigate existing attacks and make it much harder for user-space to
control the start_time a process gets assigned.

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Tom Gundersen <teg@jklm.no>
Signed-off-by: David Herrmann <dh.herrmann@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-13 09:51:04 +01:00
Satya Durga Srinivasu Prabhala
7ebdf76d85 sched: Add snapshot of Window Assisted Load Tracking (WALT)
This snapshot is taken from msm-4.14 as of
commit 871eac76e6be567 ("sched: Improve the scheduler").

Change-Id: Ib4e0b39526d3009cedebb626ece5a767d8247846
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
2019-01-02 10:56:07 -08:00
Rishabh Bhatnagar
bfee6d7f04 Merge remote-tracking branch 'origin/tmp-11da3a7' into msm-kona
* origin/tmp-11da3a7:
  Linux 4.19-rc3
  kbuild: modules_install: warn when missing System.map file
  x86/mm: Use WRITE_ONCE() when setting PTEs
  x86/apic/vector: Make error return value negative
  afs: Fix cell specification to permit an empty address list
  KVM: LAPIC: Fix pv ipis out-of-bounds access
  KVM: nVMX: Fix loss of pending IRQ/NMI before entering L2
  arm64: KVM: Remove pgd_lock
  KVM: Remove obsolete kvm_unmap_hva notifier backend
  arm64: KVM: Only force FPEXC32_EL2.EN if trapping FPSIMD
  KVM: arm/arm64: Clean dcache to PoC when changing PTE due to CoW
  i2c: xiic: Record xilinx i2c with Zynq fragment
  clocksource: Revert "Remove kthread"
  i2c: xiic: Make the start and the byte count write atomic
  irqchip/gic-v3-its: Cap lpi_id_bits to reduce memory footprint
  block: bfq: swap puts in bfqg_and_blkg_put
  memory: ti-aemif: fix a potential NULL-pointer dereference
  arm64: fix erroneous warnings in page freeing functions
  firmware: arm_scmi: fix divide by zero when sustained_perf_level is zero
  printk/tracing: Do not trace printk_nmi_enter()
  rbd: support cloning across namespaces
  rbd: factor out get_parent_info()
  ceph: avoid a use-after-free in ceph_destroy_options()
  cpu/hotplug: Prevent state corruption on error rollback
  cpu/hotplug: Adjust misplaced smb() in cpuhp_thread_fun()
  x86/process: Don't mix user/kernel regs in 64bit __show_regs()
  x86/tsc: Prevent result truncation on 32bit
  ACPI / LPSS: Force LPSS quirks on boot
  ACPI / bus: Only call dmi_check_system() on X86
  block: don't warn when doing fsync on read-only devices
  hwmon: rpi: add module alias to raspberrypi-hwmon
  tracing: Add back in rcu_irq_enter/exit_irqson() for rcuidle tracepoints
  nds32: linker script: GCOV kernel may refers data in __exit
  nilfs2: convert to SPDX license tags
  drivers/dax/device.c: convert variable to vm_fault_t type
  lib/Kconfig.debug: fix three typos in help text
  checkpatch: add __ro_after_init to known $Attribute
  mm: fix BUG_ON() in vmf_insert_pfn_pud() from VM_MIXEDMAP removal
  uapi/linux/keyctl.h: don't use C++ reserved keyword as a struct member name
  memory_hotplug: fix kernel_panic on offline page processing
  checkpatch: add optional static const to blank line declarations test
  ipc/shm: properly return EIDRM in shm_lock()
  mm/hugetlb: filter out hugetlb pages if HUGEPAGE migration is not supported.
  mm/util.c: improve kvfree() kerneldoc
  tools/vm/page-types.c: fix "defined but not used" warning
  tools/vm/slabinfo.c: fix sign-compare warning
  kmemleak: always register debugfs file
  mm: respect arch_dup_mmap() return value
  mm, oom: fix missing tlb_finish_mmu() in __oom_reap_task_mm().
  mm: memcontrol: print proper OOM header when no eligible victim left
  ARC: don't check for HIGHMEM pages in arch_dma_alloc
  ARC: IOC: panic if both IOC and ZONE_HIGHMEM enabled
  ARC: dma [IOC] Enable per device io coherency
  net: phy: sfp: Handle unimplemented hwmon limits and alarms
  net: sched: action_ife: take reference to meta module
  act_ife: fix a potential use-after-free
  net/mlx5: Fix SQ offset in QPs with small RQ
  nbd: don't allow invalid blocksize settings
  i2c: i801: fix DNV's SMBCTRL register offset
  KVM: s390: Properly lock mm context allow_gmap_hpage_1m setting
  KVM: s390: vsie: copy wrapping keys to right place
  KVM: s390: Fix pfmf and conditional skey emulation
  nds32: fix build error because of wrong semicolon
  nds32: Fix a kernel panic issue because of wrong frame pointer access.
  nds32: Only print one page of stack when die to prevent printing too much information.
  nds32: Add macro definition for offset of lp register on stack
  nds32: Remove the deprecated ABI implementation
  nds32/stack: Get real return address by using ftrace_graph_ret_addr
  nds32/ftrace: Support dynamic function graph tracer
  nds32/ftrace: Support dynamic function tracer
  nds32/ftrace: Add RECORD_MCOUNT support
  nds32/ftrace: Support static function graph tracer
  nds32/ftrace: Support static function tracer
  nds32: Extract the checking and getting pointer to a macro
  nds32: Clean up the coding style
  nds32: Fix get_user/put_user macro expand pointer problem
  nds32: Fix empty call trace
  nds32: add NULL entry to the end of_device_id array
  nds32: fix logic for module
  tipc: correct spelling errors for tipc_topsrv_queue_evt() comments
  tipc: correct spelling errors for struct tipc_bc_base's comment
  bnxt_en: Do not adjust max_cp_rings by the ones used by RDMA.
  bnxt_en: Clean up unused functions.
  bnxt_en: Fix firmware signaled resource change logic in open.
  sctp: not traverse asoc trans list if non-ipv6 trans exists for ipv6_flowlabel
  sctp: fix invalid reference to the index variable of the iterator
  net/ibm/emac: wrong emac_calc_base call was used by typo
  net: sched: null actions array pointer before releasing action
  drm/i915/dp_mst: Fix enabling pipe clock for all streams
  drm/i915/dsc: Fix PPS register definition macros for 2nd VDSC engine
  drm/i915: Re-apply "Perform link quality check, unconditionally during long pulse"
  vhost: fix VHOST_GET_BACKEND_FEATURES ioctl request definition
  r8169: add support for NCube 8168 network card
  ip6_tunnel: respect ttl inherit for ip6tnl
  ALSA: hda: Fix several mismatch for register mask and value
  apparmor: fix bad debug check in apparmor_secid_to_secctx()
  ALSA: rawmidi: Initialize allocated buffers
  fsnotify: fix ignore mask logic in fsnotify()
  timekeeping: Fix declaration of read_persistent_wall_and_boot_offset()
  x86: Fix kernel-doc atomic.h warnings
  mac80211: shorten the IBSS debug messages
  mac80211: don't Tx a deauth frame if the AP forbade Tx
  mac80211: Fix station bandwidth setting after channel switch
  mac80211: fix a race between restart and CSA flows
  mac80211: fix WMM TXOP calculation
  cfg80211: fix a type issue in ieee80211_chandef_to_operating_class()
  mac80211: fix an off-by-one issue in A-MSDU max_subframe computation
  drm/i915/gvt: Give new born vGPU higher scheduling chance
  cifs: connect to servername instead of IP for IPC$ share
  smb3: check for and properly advertise directory lease support
  smb3: minor debugging clarifications in rfc1001 len processing
  SMB3: Backup intent flag missing for directory opens with backupuid mounts
  fs/cifs: don't translate SFM_SLASH (U+F026) to backslash
  m68k: fix early memory reservation for ColdFire MMU systems
  uapi: Fix linux/rds.h userspace compilation errors.
  net: cadence: Fix a sleep-in-atomic-context bug in macb_halt_tx()
  i2c: imx-lpi2c: Remove mx8dv compatible entry
  dt-bindings: imx-lpi2c: Remove mx8dv compatible entry
  i2c: uniphier-f: issue STOP only for last message or I2C_M_STOP
  i2c: uniphier: issue STOP only for last message or I2C_M_STOP
  net/ipv6: Only update MTU metric if it set
  net: ethernet: cpsw-phy-sel: prefer phandle for phy sel
  dt-bindings: net: cpsw: Document cpsw-phy-sel usage but prefer phandle
  igmp: fix incorrect unsolicit report count after link down and up
  igmp: fix incorrect unsolicit report count when join group
  bpf: avoid misuse of psock when TCP_ULP_BPF collides with another ULP
  tools/bpf: bpftool, add xskmap in map types
  bpf: Fix bpf_msg_pull_data()
  kbuild: make missing $DEPMOD a Warning instead of an Error
  kconfig: do not require pkg-config on make {menu,n}config
  x86/microcode: Update the new microcode revision unconditionally
  x86/microcode: Make sure boot_cpu_data.microcode is up-to-date
  of/platform: initialise AMBA default DMA masks
  sparc: set a default 32-bit dma mask for OF devices
  ipv6: don't get lwtstate twice in ip6_rt_copy_init()
  random: make CPU trust a boot parameter
  kernel/dma/direct: take DMA offset into account in dma_direct_supported
  ibmvnic: Include missing return code checks in reset function
  selftests: pmtu: detect correct binary to ping ipv6 addresses
  selftests: pmtu: maximum MTU for vti4 is 2^16-1-20
  tcp: do not restart timewait timer on rst reception
  net/rds: RDS is not Radio Data System
  hv_netvsc: Fix a deadlock by getting rtnl lock earlier in netvsc_probe()
  nfp: wait for posted reconfigs when disabling the device
  Revert "packet: switch kvzalloc to allocate memory"
  md-cluster: release RESYNC lock after the last resync message
  RAID10 BUG_ON in raise_barrier when force is true and conf->barrier is 0
  md/raid5-cache: disable reshape completely
  blkcg: use tryget logic when associating a blkg with a bio
  blkcg: delay blkg destruction until after writeback has finished
  Revert "blk-throttle: fix race between blkcg_bio_issue_check() and cgroup_rmdir()"
  ARC: dma [IOC]: mark DMA devices connected as dma-coherent
  ARC: atomics: unbork atomic_fetch_##op()
  MIPS: VDSO: Match data page cache colouring when D$ aliases
  kconfig: remove a spurious self-assignment
  scripts/setlocalversion: git: Make -dirty check more robust
  gpio: Fix crash due to registration race
  arc: remove redundant GCC version checks
  tools/kvm_stat: re-animate display of dead guests
  tools/kvm_stat: indicate dead guests as such
  tools/kvm_stat: handle guest removals more gracefully
  tools/kvm_stat: don't reset stats when setting PID filter for debugfs
  tools/kvm_stat: fix updates for dead guests
  tools/kvm_stat: fix handling of invalid paths in debugfs provider
  tools/kvm_stat: fix python3 issues
  KVM: x86: Unexport x86_emulate_instruction()
  KVM: x86: Rename emulate_instruction() to kvm_emulate_instruction()
  KVM: x86: Do not re-{try,execute} after failed emulation in L2
  KVM: x86: Default to not allowing emulation retry in kvm_mmu_page_fault
  KVM: x86: Merge EMULTYPE_RETRY and EMULTYPE_ALLOW_REEXECUTE
  KVM: x86: Invert emulation re-execute behavior to make it opt-in
  KVM: x86: SVM: Set EMULTYPE_NO_REEXECUTE for RSM emulation
  KVM: VMX: Do not allow reexecute_instruction() when skipping MMIO instr
  KVM: SVM: remove unused variable dst_vaddr_end
  KVM: nVMX: avoid redundant double assignment of nested_run_pending
  ALSA: hda - Fix cancel_work_sync() stall from jackpoll work
  mac80211: always account for A-MSDU header changes
  mac80211: do not convert to A-MSDU if frag/subframe limited
  cfg80211: nl80211_update_ft_ies() to validate NL80211_ATTR_IE
  tc-testing: add test-cases for numeric and invalid control action
  net_sched: reject unknown tcfa_action values
  net: mvpp2: initialize port of_node pointer
  drm/i915/gvt: Fix drm_format_mod value for vGPU plane
  drm/i915/gvt: move intel_runtime_pm_get out of spin_lock in stop_schedule
  drm/i915/gvt: Handle GEN9_WM_CHICKEN3 with F_CMD_ACCESS.
  drm/i915/gvt: Make correct handling to vreg BXT_PHY_CTL_FAMILY
  drm/i915/gvt: emulate gen9 dbuf ctl register access
  net: bcmgenet: use MAC link status for fixed phy
  net: stmmac: build the dwmac-socfpga platform driver for Stratix10
  net: rtnl: return early from rtnl_unregister_all when protocol isn't registered
  ipv6: fix cleanup ordering for pingv6 registration
  ipv6: fix cleanup ordering for ip6_mr failure
  net/sched: act_pedit: fix dump of extended layered op
  sh_eth: Add R7S9210 support
  net: hns: add netif_carrier_off before change speed and duplex
  net: hns: add the code for cleaning pkt in chip
  r8169: set RxConfig after tx/rx is enabled for RTL8169sb/8110sb devices
  tipc: switch to rhashtable iterator
  Revert "net: stmmac: Do not keep rearming the coalesce timer in stmmac_xmit"
  tipc: fix a missing rhashtable_walk_exit()
  vti6: remove !skb->ignore_df check from vti6_xmit()
  bpf: fix sg shift repair start offset in bpf_msg_pull_data
  bpf: fix shift upon scatterlist ring wrap-around in bpf_msg_pull_data
  bpf: fix msg->data/data_end after sg shift repair in bpf_msg_pull_data
  gpio: dwapb: Fix error handling in dwapb_gpio_probe()
  gpiolib-acpi: Register GpioInt ACPI event handlers from a late_initcall
  gpiolib: acpi: Switch to cansleep version of GPIO library call
  mac80211: avoid kernel panic when building AMSDU from non-linear SKB
  mac80211: mesh: fix HWMP sequence numbering to follow standard
  gpio: adp5588: Fix sleep-in-atomic-context bug
  bpf: fix several offset tests in bpf_msg_pull_data
  nl80211: Pass center frequency in kHz instead of MHz
  nl80211: Fix nla_put_u8 to u16 for NL80211_WMMR_TXOP
  mac80211_hwsim: Fix possible Spectre-v1 for hwsim_world_regdom_custom
  mac80211: don't update the PM state of a peer upon a multicast frame
  cfg80211: make wmm_rule part of the reg_rule structure
  mac80211_hwsim: correct use of IEEE80211_VHT_CAP_RXSTBC_X
  mac80211: correct use of IEEE80211_VHT_CAP_RXSTBC_X
  bpf: sockmap, decrement copied count correctly in redirect error case
  bpf: fix build error with clang
  bpf, sockmap: fix psock refcount leak in bpf_tcp_recvmsg
  bpf, sockmap: fix potential use after free in bpf_tcp_close
  net/rds: Use rdma_read_gids to get connection SGID/DGID in IPv6
  net: dsa: Drop GPIO includes
  tipc: fix the big/little endian issue in tipc_dest
  net: sched: return -ENOENT when trying to remove filter from non-existent chain
  net: sched: fix extack error message when chain is failed to be created
  erspan: set erspan_ver to 1 by default when adding an erspan dev
  sctp: remove useless start_fail from sctp_ht_iter in proc
  sctp: hold transport before accessing its asoc in sctp_transport_get_next
  scsi: aacraid: fix a signedness bug
  Revert "scsi: core: avoid host-wide host_busy counter for scsi_mq"
  Revert "scsi: core: fix scsi_host_queue_ready"
  scsi: libata: Add missing newline at end of file
  scsi: target: iscsi: cxgbit: use pr_debug() instead of pr_info()
  scsi: hpsa: limit transfer length to 1MB, not 512kB
  scsi: lpfc: Correct MDS diag and nvmet configuration
  scsi: lpfc: Default fdmi_on to on
  scsi: csiostor: fix incorrect port capabilities
  scsi: csiostor: add a check for NULL pointer after kmalloc()
  scsi: documentation: add scsi_mod.use_blk_mq to scsi-parameters
  scsi: core: Update SCSI_MQ_DEFAULT help text to match default
  ARC: sort Kconfig
  ARC: cleanup show_faulting_vma()
  ARC: [plat-axs*]: Enable SWAP
  ARC: [plat-axs*/plat-hsdk]: Allow U-Boot to pass MAC-address to the kernel
  ARC: configs: cleanup
  arm64: allwinner: dts: h6: fix Pine H64 MMC bus width
  btrfs: Fix suspicious RCU usage warning in btrfs_debug_in_rcu
  btrfs: use after free in btrfs_quota_enable
  btrfs: btrfs_shrink_device should call commit transaction at the end
  btrfs: fix qgroup_free wrong num_bytes in btrfs_subvolume_reserve_metadata
  Btrfs: fix data corruption when deduplicating between different files
  Btrfs: sync log after logging new name
  cfg80211: remove division by size of sizeof(struct ieee80211_wmm_rule)
  KVM: PPC: Book3S HV: Don't truncate HPTE index in xlate function
  Btrfs: fix unexpected failure of nocow buffered writes after snapshotting when low on space
  mac80211_hwsim: require at least one channel
  KVM: PPC: Book3S HV: Use correct pagesize in kvm_unmap_radix()
  mac80211: Run TXQ teardown code before de-registering interfaces
  rfkill-gpio: include linux/mod_devicetable.h

Change-Id: Ic6d1654e67ece823a5fce6ae18d241ad350bfb08
Signed-off-by: Rishabh Bhatnagar <rishabhb@codeaurora.org>
2018-09-14 11:24:01 -07:00
Nadav Amit
1ed0cc5a01 mm: respect arch_dup_mmap() return value
Commit d70f2a14b7 ("include/linux/sched/mm.h: uninline mmdrop_async(),
etc") ignored the return value of arch_dup_mmap(). As a result, on x86,
a failure to duplicate the LDT (e.g. due to memory allocation error)
would leave the duplicated memory mapping in an inconsistent state.

Fix by using the return value, as it was before the change.

Link: http://lkml.kernel.org/r/20180823051229.211856-1-namit@vmware.com
Fixes: d70f2a14b7 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc")
Signed-off-by: Nadav Amit <namit@vmware.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: <stable@vger.kernel.org>

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-09-04 16:45:02 -07:00
Sultan Alsawaf
9c752f5721 ANDROID: Fix massive cpufreq_times memory leaks
Every time _cpu_up() is called for a CPU, idle_thread_get() is called
which then re-initializes a CPU's idle thread that was already
previously created and cached in a global variable in
smpboot.c. idle_thread_get() calls init_idle() which then calls
__sched_fork(). __sched_fork() is where cpufreq_task_times_init() is,
and cpufreq_task_times_init() allocates memory for the task struct's
time_in_state array.

Since idle_thread_get() reuses a task struct instance that was already
previously created, this means that every time it calls init_idle(),
cpufreq_task_times_init() allocates this array again and overwrites
the existing allocation that the idle thread already had.

This causes memory to be leaked every time a CPU is onlined. In order
to fix this, move allocation of time_in_state into _do_fork to avoid
allocating it at all for idle threads. The cpufreq times interface is
intended to be used for tracking userspace tasks, so we can safely
remove it from the kernel's idle threads without killing any
functionality.

But that's not all!

Task structs can be freed outside of release_task(), which creates
another memory leak because a task struct can be freed without having
its cpufreq times allocation freed. To fix this, free the cpufreq
times allocation at the same time that task struct allocations are
freed, in free_task().

Since free_task() can also be called in error paths of copy_process()
after dup_task_struct(), set time_in_state to NULL immediately after
calling dup_task_struct() to avoid possible double free.

Bug description and fix adapted from patch submitted by
Sultan Alsawaf <sultanxda@gmail.com> at
https://android-review.googlesource.com/c/kernel/msm/+/700134

Bug: 110044919
Test: Hikey960 builds, boots & reports /proc/<pid>/time_in_state
correctly
Change-Id: I12fe7611fc88eb7f6c39f8f7629ad27b6ec4722c
Signed-off-by: Connor O'Brien <connoro@google.com>
2018-08-28 17:10:42 +05:30
Linus Torvalds
cd9b44f907 Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - the rest of MM

 - procfs updates

 - various misc things

 - more y2038 fixes

 - get_maintainer updates

 - lib/ updates

 - checkpatch updates

 - various epoll updates

 - autofs updates

 - hfsplus

 - some reiserfs work

 - fatfs updates

 - signal.c cleanups

 - ipc/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (166 commits)
  ipc/util.c: update return value of ipc_getref from int to bool
  ipc/util.c: further variable name cleanups
  ipc: simplify ipc initialization
  ipc: get rid of ids->tables_initialized hack
  lib/rhashtable: guarantee initial hashtable allocation
  lib/rhashtable: simplify bucket_table_alloc()
  ipc: drop ipc_lock()
  ipc/util.c: correct comment in ipc_obtain_object_check
  ipc: rename ipcctl_pre_down_nolock()
  ipc/util.c: use ipc_rcu_putref() for failues in ipc_addid()
  ipc: reorganize initialization of kern_ipc_perm.seq
  ipc: compute kern_ipc_perm.id under the ipc lock
  init/Kconfig: remove EXPERT from CHECKPOINT_RESTORE
  fs/sysv/inode.c: use ktime_get_real_seconds() for superblock stamp
  adfs: use timespec64 for time conversion
  kernel/sysctl.c: fix typos in comments
  drivers/rapidio/devices/rio_mport_cdev.c: remove redundant pointer md
  fork: don't copy inconsistent signal handler state to child
  signal: make get_signal() return bool
  signal: make sigkill_pending() return bool
  ...
2018-08-22 12:34:08 -07:00
Jann Horn
06e62a46bb fork: don't copy inconsistent signal handler state to child
Before this change, if a multithreaded process forks while one of its
threads is changing a signal handler using sigaction(), the memcpy() in
copy_sighand() can race with the struct assignment in do_sigaction().  It
isn't clear whether this can cause corruption of the userspace signal
handler pointer, but it definitely can cause inconsistency between
different fields of struct sigaction.

Take the appropriate spinlock to avoid this.

I have tested that this patch prevents inconsistency between sa_sigaction
and sa_flags, which is possible before this patch.

Link: http://lkml.kernel.org/r/20180702145108.73189-1-jannh@google.com
Signed-off-by: Jann Horn <jannh@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:51 -07:00
Dmitry Vyukov
a2e5144538 kernel/hung_task.c: allow to set checking interval separately from timeout
Currently task hung checking interval is equal to timeout, as the result
hung is detected anywhere between timeout and 2*timeout.  This is fine for
most interactive environments, but this hurts automated testing setups
(syzbot).  In an automated setup we need to strictly order CPU lockup <
RCU stall < workqueue lockup < task hung < silent loss, so that RCU stall
is not detected as task hung and task hung is not detected as silent
machine loss.  The large variance in task hung detection timeout requires
setting silent machine loss timeout to a very large value (e.g.  if task
hung is 3 mins, then silent loss need to be set to ~7 mins).  The
additional 3 minutes significantly reduce testing efficiency because
usually we crash kernel within a minute, and this can add hours to bug
localization process as it needs to do dozens of tests.

Allow setting checking interval separately from timeout.  This allows to
set timeout to, say, 3 minutes, but checking interval to 10 secs.

The interval is controlled via a new hung_task_check_interval_secs sysctl,
similar to the existing hung_task_timeout_secs sysctl.  The default value
of 0 results in the current behavior: checking interval is equal to
timeout.

[akpm@linux-foundation.org: update hung_task_timeout_max's comment]
Link: http://lkml.kernel.org/r/20180611111004.203513-1-dvyukov@google.com
Signed-off-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:47 -07:00
Andrew Morton
a670468f5e mm: zero out the vma in vma_init()
Rather than in vm_area_alloc().  To ensure that the various oddball
stack-based vmas are in a good state.  Some of the callers were zeroing
them out, others were not.

Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-22 10:52:44 -07:00
Linus Torvalds
0214f46b3a Merge branch 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace
Pull core signal handling updates from Eric Biederman:
 "It was observed that a periodic timer in combination with a
  sufficiently expensive fork could prevent fork from every completing.
  This contains the changes to remove the need for that restart.

  This set of changes is split into several parts:

   - The first part makes PIDTYPE_TGID a proper pid type instead
     something only for very special cases. The part starts using
     PIDTYPE_TGID enough so that in __send_signal where signals are
     actually delivered we know if the signal is being sent to a a group
     of processes or just a single process.

   - With that prep work out of the way the logic in fork is modified so
     that fork logically makes signals received while it is running
     appear to be received after the fork completes"

* 'siginfo-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (22 commits)
  signal: Don't send signals to tasks that don't exist
  signal: Don't restart fork when signals come in.
  fork: Have new threads join on-going signal group stops
  fork: Skip setting TIF_SIGPENDING in ptrace_init_task
  signal: Add calculate_sigpending()
  fork: Unconditionally exit if a fatal signal is pending
  fork: Move and describe why the code examines PIDNS_ADDING
  signal: Push pid type down into complete_signal.
  signal: Push pid type down into __send_signal
  signal: Push pid type down into send_signal
  signal: Pass pid type into do_send_sig_info
  signal: Pass pid type into send_sigio_to_task & send_sigurg_to_task
  signal: Pass pid type into group_send_sig_info
  signal: Pass pid and pid type into send_sigqueue
  posix-timers: Noralize good_sigevent
  signal: Use PIDTYPE_TGID to clearly store where file signals will be sent
  pid: Implement PIDTYPE_TGID
  pids: Move the pgrp and session pid pointers from task_struct to signal_struct
  kvm: Don't open code task_pid in kvm_vcpu_ioctl
  pids: Compute task_tgid using signal->leader_pid
  ...
2018-08-21 13:47:29 -07:00
Shakeel Butt
d46eb14b73 fs: fsnotify: account fsnotify metadata to kmemcg
Patch series "Directed kmem charging", v8.

The Linux kernel's memory cgroup allows limiting the memory usage of the
jobs running on the system to provide isolation between the jobs.  All
the kernel memory allocated in the context of the job and marked with
__GFP_ACCOUNT will also be included in the memory usage and be limited
by the job's limit.

The kernel memory can only be charged to the memcg of the process in
whose context kernel memory was allocated.  However there are cases
where the allocated kernel memory should be charged to the memcg
different from the current processes's memcg.  This patch series
contains two such concrete use-cases i.e.  fsnotify and buffer_head.

The fsnotify event objects can consume a lot of system memory for large
or unlimited queues if there is either no or slow listener.  The events
are allocated in the context of the event producer.  However they should
be charged to the event consumer.  Similarly the buffer_head objects can
be allocated in a memcg different from the memcg of the page for which
buffer_head objects are being allocated.

To solve this issue, this patch series introduces mechanism to charge
kernel memory to a given memcg.  In case of fsnotify events, the memcg
of the consumer can be used for charging and for buffer_head, the memcg
of the page can be charged.  For directed charging, the caller can use
the scope API memalloc_[un]use_memcg() to specify the memcg to charge
for all the __GFP_ACCOUNT allocations within the scope.

This patch (of 2):

A lot of memory can be consumed by the events generated for the huge or
unlimited queues if there is either no or slow listener.  This can cause
system level memory pressure or OOMs.  So, it's better to account the
fsnotify kmem caches to the memcg of the listener.

However the listener can be in a different memcg than the memcg of the
producer and these allocations happen in the context of the event
producer.  This patch introduces remote memcg charging API which the
producer can use to charge the allocations to the memcg of the listener.

There are seven fsnotify kmem caches and among them allocations from
dnotify_struct_cache, dnotify_mark_cache, fanotify_mark_cache and
inotify_inode_mark_cachep happens in the context of syscall from the
listener.  So, SLAB_ACCOUNT is enough for these caches.

The objects from fsnotify_mark_connector_cachep are not accounted as
they are small compared to the notification mark or events and it is
unclear whom to account connector to since it is shared by all events
attached to the inode.

The allocations from the event caches happen in the context of the event
producer.  For such caches we will need to remote charge the allocations
to the listener's memcg.  Thus we save the memcg reference in the
fsnotify_group structure of the listener.

This patch has also moved the members of fsnotify_group to keep the size
same, at least for 64 bit build, even with additional member by filling
the holes.

[shakeelb@google.com: use GFP_KERNEL_ACCOUNT rather than open-coding it]
  Link: http://lkml.kernel.org/r/20180702215439.211597-1-shakeelb@google.com
Link: http://lkml.kernel.org/r/20180627191250.209150-2-shakeelb@google.com
Signed-off-by: Shakeel Butt <shakeelb@google.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Roman Gushchin <guro@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-08-17 16:20:30 -07:00
Linus Torvalds
73ba2fb33c Merge tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block
Pull block updates from Jens Axboe:
 "First pull request for this merge window, there will also be a
  followup request with some stragglers.

  This pull request contains:

   - Fix for a thundering heard issue in the wbt block code (Anchal
     Agarwal)

   - A few NVMe pull requests:
      * Improved tracepoints (Keith)
      * Larger inline data support for RDMA (Steve Wise)
      * RDMA setup/teardown fixes (Sagi)
      * Effects log suppor for NVMe target (Chaitanya Kulkarni)
      * Buffered IO suppor for NVMe target (Chaitanya Kulkarni)
      * TP4004 (ANA) support (Christoph)
      * Various NVMe fixes

   - Block io-latency controller support. Much needed support for
     properly containing block devices. (Josef)

   - Series improving how we handle sense information on the stack
     (Kees)

   - Lightnvm fixes and updates/improvements (Mathias/Javier et al)

   - Zoned device support for null_blk (Matias)

   - AIX partition fixes (Mauricio Faria de Oliveira)

   - DIF checksum code made generic (Max Gurtovoy)

   - Add support for discard in iostats (Michael Callahan / Tejun)

   - Set of updates for BFQ (Paolo)

   - Removal of async write support for bsg (Christoph)

   - Bio page dirtying and clone fixups (Christoph)

   - Set of bcache fix/changes (via Coly)

   - Series improving blk-mq queue setup/teardown speed (Ming)

   - Series improving merging performance on blk-mq (Ming)

   - Lots of other fixes and cleanups from a slew of folks"

* tag 'for-4.19/block-20180812' of git://git.kernel.dk/linux-block: (190 commits)
  blkcg: Make blkg_root_lookup() work for queues in bypass mode
  bcache: fix error setting writeback_rate through sysfs interface
  null_blk: add lock drop/acquire annotation
  Blk-throttle: reduce tail io latency when iops limit is enforced
  block: paride: pd: mark expected switch fall-throughs
  block: Ensure that a request queue is dissociated from the cgroup controller
  block: Introduce blk_exit_queue()
  blkcg: Introduce blkg_root_lookup()
  block: Remove two superfluous #include directives
  blk-mq: count the hctx as active before allocating tag
  block: bvec_nr_vecs() returns value for wrong slab
  bcache: trivial - remove tailing backslash in macro BTREE_FLAG
  bcache: make the pr_err statement used for ENOENT only in sysfs_attatch section
  bcache: set max writeback rate when I/O request is idle
  bcache: add code comments for bset.c
  bcache: fix mistaken comments in request.c
  bcache: fix mistaken code comments in bcache.h
  bcache: add a comment in super.c
  bcache: avoid unncessary cache prefetch bch_btree_node_get()
  bcache: display rate debug parameters to 0 when writeback is not running
  ...
2018-08-14 10:23:25 -07:00
Linus Torvalds
203b4fc903 Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Thomas Gleixner:

 - Make lazy TLB mode even lazier to avoid pointless switch_mm()
   operations, which reduces CPU load by 1-2% for memcache workloads

 - Small cleanups and improvements all over the place

* 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/mm: Remove redundant check for kmem_cache_create()
  arm/asm/tlb.h: Fix build error implicit func declaration
  x86/mm/tlb: Make clear_asid_other() static
  x86/mm/tlb: Skip atomic operations for 'init_mm' in switch_mm_irqs_off()
  x86/mm/tlb: Always use lazy TLB mode
  x86/mm/tlb: Only send page table free TLB flush to lazy TLB CPUs
  x86/mm/tlb: Make lazy TLB mode lazier
  x86/mm/tlb: Restructure switch_mm_irqs_off()
  x86/mm/tlb: Leave lazy TLB mode at page table free time
  mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids
  x86/mm: Add TLB purge to free pmd/pte page interfaces
  ioremap: Update pgtable free interfaces with addr
  x86/mm: Disable ioremap free page handling on x86-PAE
2018-08-13 16:29:35 -07:00
Eric W. Biederman
c3ad2c3b02 signal: Don't restart fork when signals come in.
Wen Yang <wen.yang99@zte.com.cn> and majiang <ma.jiang@zte.com.cn>
report that a periodic signal received during fork can cause fork to
continually restart preventing an application from making progress.

The code was being overly pessimistic.  Fork needs to guarantee that a
signal sent to multiple processes is logically delivered before the
fork and just to the forking process or logically delivered after the
fork to both the forking process and it's newly spawned child.  For
signals like periodic timers that are always delivered to a single
process fork can safely complete and let them appear to logically
delivered after the fork().

While examining this issue I also discovered that fork today will miss
signals delivered to multiple processes during the fork and handled by
another thread.  Similarly the current code will also miss blocked
signals that are delivered to multiple process, as those signals will
not appear pending during fork.

Add a list of each thread that is currently forking, and keep on that
list a signal set that records all of the signals sent to multiple
processes.  When fork completes initialize the new processes
shared_pending signal set with it.  The calculate_sigpending function
will see those signals and set TIF_SIGPENDING causing the new task to
take the slow path to userspace to handle those signals.  Making it
appear as if those signals were received immediately after the fork.

It is not possible to send real time signals to multiple processes and
exceptions don't go to multiple processes, which means that that are
no signals sent to multiple processes that require siginfo.  This
means it is safe to not bother collecting siginfo on signals sent
during fork.

The sigaction of a child of fork is initially the same as the
sigaction of the parent process.  So a signal the parent ignores the
child will also initially ignore.  Therefore it is safe to ignore
signals sent to multiple processes and ignored by the forking process.

Signals sent to only a single process or only a single thread and delivered
during fork are treated as if they are received after the fork, and generally
not dealt with.  They won't cause any problems.

V2: Added removal from the multiprocess list on failure.
V3: Use -ERESTARTNOINTR directly
V4: - Don't queue both SIGCONT and SIGSTOP
    - Initialize signal_struct.multiprocess in init_task
    - Move setting of shared_pending to before the new task
      is visible to signals.  This prevents signals from comming
      in before shared_pending.signal is set to delayed.signal
      and being lost.
V5: - rework list add and delete to account for idle threads
v6: - Use sigdelsetmask when removing stop signals

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=200447
Reported-by: Wen Yang <wen.yang99@zte.com.cn> and
Reported-by: majiang <ma.jiang@zte.com.cn>
Fixes: 4a2c7a7837 ("[PATCH] make fork() atomic wrt pgrp/session signals")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-08-09 13:07:01 -05:00
Jens Axboe
05b9ba4b55 Merge tag 'v4.18-rc6' into for-4.19/block2
Pull in 4.18-rc6 to get the NVMe core AEN change to avoid a
merge conflict down the line.

Signed-of-by: Jens Axboe <axboe@kernel.dk>
2018-08-05 19:32:09 -06:00
Eric W. Biederman
924de3b8c9 fork: Have new threads join on-going signal group stops
There are only two signals that are delivered to every member of a
signal group: SIGSTOP and SIGKILL.  Signal delivery requires every
signal appear to be delivered either before or after a clone syscall.
SIGKILL terminates the clone so does not need to be considered.  Which
leaves only SIGSTOP that needs to be considered when creating new
threads.

Today in the event of a group stop TIF_SIGPENDING will get set and the
fork will restart ensuring the fork syscall participates in the group
stop.

A fork (especially of a process with a lot of memory) is one of the
most expensive system so we really only want to restart a fork when
necessary.

It is easy so check to see if a SIGSTOP is ongoing and have the new
thread join it immediate after the clone completes.  Making it appear
the clone completed happened just before the SIGSTOP.

The calculate_sigpending function will see the bits set in jobctl and
set TIF_SIGPENDING to ensure the new task takes the slow path to userspace.

V2: The call to task_join_group_stop was moved before the new task is
    added to the thread group list.  This should not matter as
    sighand->siglock is held over both the addition of the threads,
    the call to task_join_group_stop and do_signal_stop.  But the change
    is trivial and it is one less thing to worry about when reading
    the code.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-08-03 20:20:14 -05:00
Josef Bacik
2c323017e3 blk-cgroup: clear the throttle queue on fork
We were hitting a panic in production where we put too many times on the
request queue.  This is because we'd get the throttle_queue of the
parent if we fork()'ed while we needed to be throttled, but we didn't
have a reference on it.  Instead just clear these flags on fork so the
child doesn't pay for the sins of its father.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-08-01 09:16:04 -06:00
Kirill A. Shutemov
027232da7c mm: introduce vma_init()
Not all VMAs allocated with vm_area_alloc().  Some of them allocated on
stack or in data segment.

The new helper can be use to initialize VMA properly regardless where it
was allocated.

Link: http://lkml.kernel.org/r/20180724121139.62570-2-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@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>
2018-07-26 19:38:03 -07:00
Eric W. Biederman
7673bf553b fork: Unconditionally exit if a fatal signal is pending
In practice this does not change anything as testing for fatal_signal_pending
and exiting for with an error code duplicates the work of the next clause
which recalculates pending signals and then exits fork if any are pending.
In both cases the pending signal will trigger the slow path when existing
to userspace, and the fatal signal will cause do_exit to be called.

The advantage of making this a separate test is that it makes it clear
processing the fatal signal will terminate the fork, and it allows the
rest of the signal logic to be updated without fear that this important
case will be lost.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-23 08:01:10 -05:00
Eric W. Biederman
4ca1d3ee46 fork: Move and describe why the code examines PIDNS_ADDING
Normally this would be something that would be handled by handling
signals that are sent to a group of processes but in this case the
forking process is not a member of the group being signaled.  Thus
special code is needed to prevent a race with pid namespaces exiting,
and fork adding new processes within them.

Move this test up before the signal restart just in case signals are
also pending.  Fatal conditions should take presedence over restarts.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-23 07:57:12 -05:00
Linus Torvalds
490fc05386 mm: make vm_area_alloc() initialize core fields
Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 15:24:03 -07:00
Linus Torvalds
95faf6992d mm: make vm_area_dup() actually copy the old vma data
.. and re-initialize th eanon_vma_chain head.

This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 14:48:45 -07:00
Linus Torvalds
3928d4f5ee mm: use helper functions for allocating and freeing vm_area structs
The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-07-21 13:48:51 -07:00
Eric W. Biederman
6883f81aac pid: Implement PIDTYPE_TGID
Everywhere except in the pid array we distinguish between a tasks pid and
a tasks tgid (thread group id).  Even in the enumeration we want that
distinction sometimes so we have added __PIDTYPE_TGID.  With leader_pid
we almost have an implementation of PIDTYPE_TGID in struct signal_struct.

Add PIDTYPE_TGID as a first class member of the pid_type enumeration and
into the pids array.  Then remove the __PIDTYPE_TGID special case and the
leader_pid in signal_struct.

The net size increase is just an extra pointer added to struct pid and
an extra pair of pointers of an hlist_node added to task_struct.

The effect on code maintenance is the removal of a number of special
cases today and the potential to remove many more special cases as
PIDTYPE_TGID gets used to it's fullest.  The long term potential
is allowing zombie thread group leaders to exit, which will remove
a lot more special cases in the code.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Eric W. Biederman
2c4704756c pids: Move the pgrp and session pid pointers from task_struct to signal_struct
To access these fields the code always has to go to group leader so
going to signal struct is no loss and is actually a fundamental simplification.

This saves a little bit of memory by only allocating the pid pointer array
once instead of once for every thread, and even better this removes a
few potential races caused by the fact that group_leader can be changed
by de_thread, while signal_struct can not.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2018-07-21 10:43:12 -05:00
Rik van Riel
c1a2f7f0c0 mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids
The mm_struct always contains a cpumask bitmap, regardless of
CONFIG_CPUMASK_OFFSTACK. That means the first step can be to
simplify things, and simply have one bitmask at the end of the
mm_struct for the mm_cpumask.

This does necessitate moving everything else in mm_struct into
an anonymous sub-structure, which can be randomized when struct
randomization is enabled.

The second step is to determine the correct size for the
mm_struct slab object from the size of the mm_struct
(excluding the CPU bitmap) and the size the cpumask.

For init_mm we can simply allocate the maximum size this
kernel is compiled for, since we only have one init_mm
in the system, anyway.

Pointer magic by Mike Galbraith, to evade -Wstringop-overflow
getting confused by the dynamically sized array.

Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Rik van Riel <riel@surriel.com>
Acked-by: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-2-riel@surriel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2018-07-17 09:35:30 +02:00
Tetsuo Handa
655c79bb40 mm: check for SIGKILL inside dup_mmap() loop
As a theoretical problem, dup_mmap() of an mm_struct with 60000+ vmas
can loop while potentially allocating memory, with mm->mmap_sem held for
write by current thread.  This is bad if current thread was selected as
an OOM victim, for current thread will continue allocations using memory
reserves while OOM reaper is unable to reclaim memory.

As an actually observable problem, it is not difficult to make OOM
reaper unable to reclaim memory if the OOM victim is blocked at
i_mmap_lock_write() in this loop.  Unfortunately, since nobody can
explain whether it is safe to use killable wait there, let's check for
SIGKILL before trying to allocate memory.  Even without an OOM event,
there is no point with continuing the loop from the beginning if current
thread is killed.

I tested with debug printk().  This patch should be safe because we
already fail if security_vm_enough_memory_mm() or
kmem_cache_alloc(GFP_KERNEL) fails and exit_mmap() handles it.

   ***** Aborting dup_mmap() due to SIGKILL *****
   ***** Aborting dup_mmap() due to SIGKILL *****
   ***** Aborting dup_mmap() due to SIGKILL *****
   ***** Aborting dup_mmap() due to SIGKILL *****
   ***** Aborting exit_mmap() due to NULL mmap *****

[akpm@linux-foundation.org: add comment]
Link: http://lkml.kernel.org/r/201804071938.CDE04681.SOFVQJFtMHOOLF@I-love.SAKURA.ne.jp
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Rik van Riel <riel@redhat.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-15 07:55:24 +09:00
Linus Torvalds
050e9baa9d Kbuild: rename CC_STACKPROTECTOR[_STRONG] config variables
The changes to automatically test for working stack protector compiler
support in the Kconfig files removed the special STACKPROTECTOR_AUTO
option that picked the strongest stack protector that the compiler
supported.

That was all a nice cleanup - it makes no sense to have the AUTO case
now that the Kconfig phase can just determine the compiler support
directly.

HOWEVER.

It also meant that doing "make oldconfig" would now _disable_ the strong
stackprotector if you had AUTO enabled, because in a legacy config file,
the sane stack protector configuration would look like

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_NONE is not set
  # CONFIG_CC_STACKPROTECTOR_REGULAR is not set
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_STACKPROTECTOR_AUTO=y

and when you ran this through "make oldconfig" with the Kbuild changes,
it would ask you about the regular CONFIG_CC_STACKPROTECTOR (that had
been renamed from CONFIG_CC_STACKPROTECTOR_REGULAR to just
CONFIG_CC_STACKPROTECTOR), but it would think that the STRONG version
used to be disabled (because it was really enabled by AUTO), and would
disable it in the new config, resulting in:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_CC_STACKPROTECTOR=y
  # CONFIG_CC_STACKPROTECTOR_STRONG is not set
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

That's dangerously subtle - people could suddenly find themselves with
the weaker stack protector setup without even realizing.

The solution here is to just rename not just the old RECULAR stack
protector option, but also the strong one.  This does that by just
removing the CC_ prefix entirely for the user choices, because it really
is not about the compiler support (the compiler support now instead
automatially impacts _visibility_ of the options to users).

This results in "make oldconfig" actually asking the user for their
choice, so that we don't have any silent subtle security model changes.
The end result would generally look like this:

  CONFIG_HAVE_CC_STACKPROTECTOR=y
  CONFIG_CC_HAS_STACKPROTECTOR_NONE=y
  CONFIG_STACKPROTECTOR=y
  CONFIG_STACKPROTECTOR_STRONG=y
  CONFIG_CC_HAS_SANE_STACKPROTECTOR=y

where the "CC_" versions really are about internal compiler
infrastructure, not the user selections.

Acked-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-14 12:21:18 +09:00
Linus Torvalds
d82991a868 Merge branch 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull restartable sequence support from Thomas Gleixner:
 "The restartable sequences syscall (finally):

  After a lot of back and forth discussion and massive delays caused by
  the speculative distraction of maintainers, the core set of
  restartable sequences has finally reached a consensus.

  It comes with the basic non disputed core implementation along with
  support for arm, powerpc and x86 and a full set of selftests

  It was exposed to linux-next earlier this week, so it does not fully
  comply with the merge window requirements, but there is really no
  point to drag it out for yet another cycle"

* 'core-rseq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq/selftests: Provide Makefile, scripts, gitignore
  rseq/selftests: Provide parametrized tests
  rseq/selftests: Provide basic percpu ops test
  rseq/selftests: Provide basic test
  rseq/selftests: Provide rseq library
  selftests/lib.mk: Introduce OVERRIDE_TARGETS
  powerpc: Wire up restartable sequences system call
  powerpc: Add syscall detection for restartable sequences
  powerpc: Add support for restartable sequences
  x86: Wire up restartable sequence system call
  x86: Add support for restartable sequences
  arm: Wire up restartable sequences system call
  arm: Add syscall detection for restartable sequences
  arm: Add restartable sequences support
  rseq: Introduce restartable sequences system call
  uapi/headers: Provide types_32_64.h
2018-06-10 10:17:09 -07:00
Yang Shi
88aa7cc688 mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct
mmap_sem is on the hot path of kernel, and it very contended, but it is
abused too.  It is used to protect arg_start|end and evn_start|end when
reading /proc/$PID/cmdline and /proc/$PID/environ, but it doesn't make
sense since those proc files just expect to read 4 values atomically and
not related to VM, they could be set to arbitrary values by C/R.

And, the mmap_sem contention may cause unexpected issue like below:

INFO: task ps:14018 blocked for more than 120 seconds.
       Tainted: G            E 4.9.79-009.ali3000.alios7.x86_64 #1
 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this
message.
 ps              D    0 14018      1 0x00000004
 Call Trace:
   schedule+0x36/0x80
   rwsem_down_read_failed+0xf0/0x150
   call_rwsem_down_read_failed+0x18/0x30
   down_read+0x20/0x40
   proc_pid_cmdline_read+0xd9/0x4e0
   __vfs_read+0x37/0x150
   vfs_read+0x96/0x130
   SyS_read+0x55/0xc0
   entry_SYSCALL_64_fastpath+0x1a/0xc5

Both Alexey Dobriyan and Michal Hocko suggested to use dedicated lock
for them to mitigate the abuse of mmap_sem.

So, introduce a new spinlock in mm_struct to protect the concurrent
access to arg_start|end, env_start|end and others, as well as replace
write map_sem to read to protect the race condition between prctl and
sys_brk which might break check_data_rlimit(), and makes prctl more
friendly to other VM operations.

This patch just eliminates the abuse of mmap_sem, but it can't resolve
the above hung task warning completely since the later
access_remote_vm() call needs acquire mmap_sem.  The mmap_sem
scalability issue will be solved in the future.

[yang.shi@linux.alibaba.com: add comment about mmap_sem and arg_lock]
  Link: http://lkml.kernel.org/r/1524077799-80690-1-git-send-email-yang.shi@linux.alibaba.com
Link: http://lkml.kernel.org/r/1523730291-109696-1-git-send-email-yang.shi@linux.alibaba.com
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Cyrill Gorcunov <gorcunov@openvz.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mateusz Guzik <mguzik@redhat.com>
Cc: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-06-07 17:34:34 -07:00
Linus Torvalds
8b5c6a3a49 Merge tag 'audit-pr-20180605' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit
Pull audit updates from Paul Moore:
 "Another reasonable chunk of audit changes for v4.18, thirteen patches
  in total.

  The thirteen patches can mostly be broken down into one of four
  categories: general bug fixes, accessor functions for audit state
  stored in the task_struct, negative filter matches on executable
  names, and extending the (relatively) new seccomp logging knobs to the
  audit subsystem.

  The main driver for the accessor functions from Richard are the
  changes we're working on to associate audit events with containers,
  but I think they have some standalone value too so I figured it would
  be good to get them in now.

  The seccomp/audit patches from Tyler apply the seccomp logging
  improvements from a few releases ago to audit's seccomp logging;
  starting with this patchset the changes in
  /proc/sys/kernel/seccomp/actions_logged should apply to both the
  standard kernel logging and audit.

  As usual, everything passes the audit-testsuite and it happens to
  merge cleanly with your tree"

[ Heh, except it had trivial merge conflicts with the SELinux tree that
  also came in from Paul   - Linus ]

* tag 'audit-pr-20180605' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
  audit: Fix wrong task in comparison of session ID
  audit: use existing session info function
  audit: normalize loginuid read access
  audit: use new audit_context access funciton for seccomp_actions_logged
  audit: use inline function to set audit context
  audit: use inline function to get audit context
  audit: convert sessionid unset to a macro
  seccomp: Don't special case audited processes when logging
  seccomp: Audit attempts to modify the actions_logged sysctl
  seccomp: Configurable separator for the actions_logged string
  seccomp: Separate read and write code for actions_logged sysctl
  audit: allow not equal op for audit by executable
  audit: add syscall information to FEATURE_CHANGE records
2018-06-06 16:34:00 -07:00
Mathieu Desnoyers
d7822b1e24 rseq: Introduce restartable sequences system call
Expose a new system call allowing each thread to register one userspace
memory area to be used as an ABI between kernel and user-space for two
purposes: user-space restartable sequences and quick access to read the
current CPU number value from user-space.

* Restartable sequences (per-cpu atomics)

Restartables sequences allow user-space to perform update operations on
per-cpu data without requiring heavy-weight atomic operations.

The restartable critical sections (percpu atomics) work has been started
by Paul Turner and Andrew Hunter. It lets the kernel handle restart of
critical sections. [1] [2] The re-implementation proposed here brings a
few simplifications to the ABI which facilitates porting to other
architectures and speeds up the user-space fast path.

Here are benchmarks of various rseq use-cases.

Test hardware:

arm32: ARMv7 Processor rev 4 (v7l) "Cubietruck", 2-core
x86-64: Intel E5-2630 v3@2.40GHz, 16-core, hyperthreading

The following benchmarks were all performed on a single thread.

* Per-CPU statistic counter increment

                getcpu+atomic (ns/op)    rseq (ns/op)    speedup
arm32:                344.0                 31.4          11.0
x86-64:                15.3                  2.0           7.7

* LTTng-UST: write event 32-bit header, 32-bit payload into tracer
             per-cpu buffer

                getcpu+atomic (ns/op)    rseq (ns/op)    speedup
arm32:               2502.0                 2250.0         1.1
x86-64:               117.4                   98.0         1.2

* liburcu percpu: lock-unlock pair, dereference, read/compare word

                getcpu+atomic (ns/op)    rseq (ns/op)    speedup
arm32:                751.0                 128.5          5.8
x86-64:                53.4                  28.6          1.9

* jemalloc memory allocator adapted to use rseq

Using rseq with per-cpu memory pools in jemalloc at Facebook (based on
rseq 2016 implementation):

The production workload response-time has 1-2% gain avg. latency, and
the P99 overall latency drops by 2-3%.

* Reading the current CPU number

Speeding up reading the current CPU number on which the caller thread is
running is done by keeping the current CPU number up do date within the
cpu_id field of the memory area registered by the thread. This is done
by making scheduler preemption set the TIF_NOTIFY_RESUME flag on the
current thread. Upon return to user-space, a notify-resume handler
updates the current CPU value within the registered user-space memory
area. User-space can then read the current CPU number directly from
memory.

Keeping the current cpu id in a memory area shared between kernel and
user-space is an improvement over current mechanisms available to read
the current CPU number, which has the following benefits over
alternative approaches:

- 35x speedup on ARM vs system call through glibc
- 20x speedup on x86 compared to calling glibc, which calls vdso
  executing a "lsl" instruction,
- 14x speedup on x86 compared to inlined "lsl" instruction,
- Unlike vdso approaches, this cpu_id value can be read from an inline
  assembly, which makes it a useful building block for restartable
  sequences.
- The approach of reading the cpu id through memory mapping shared
  between kernel and user-space is portable (e.g. ARM), which is not the
  case for the lsl-based x86 vdso.

On x86, yet another possible approach would be to use the gs segment
selector to point to user-space per-cpu data. This approach performs
similarly to the cpu id cache, but it has two disadvantages: it is
not portable, and it is incompatible with existing applications already
using the gs segment selector for other purposes.

Benchmarking various approaches for reading the current CPU number:

ARMv7 Processor rev 4 (v7l)
Machine model: Cubietruck
- Baseline (empty loop):                                    8.4 ns
- Read CPU from rseq cpu_id:                               16.7 ns
- Read CPU from rseq cpu_id (lazy register):               19.8 ns
- glibc 2.19-0ubuntu6.6 getcpu:                           301.8 ns
- getcpu system call:                                     234.9 ns

x86-64 Intel(R) Xeon(R) CPU E5-2630 v3 @ 2.40GHz:
- Baseline (empty loop):                                    0.8 ns
- Read CPU from rseq cpu_id:                                0.8 ns
- Read CPU from rseq cpu_id (lazy register):                0.8 ns
- Read using gs segment selector:                           0.8 ns
- "lsl" inline assembly:                                   13.0 ns
- glibc 2.19-0ubuntu6 getcpu:                              16.6 ns
- getcpu system call:                                      53.9 ns

- Speed (benchmark taken on v8 of patchset)

Running 10 runs of hackbench -l 100000 seems to indicate, contrary to
expectations, that enabling CONFIG_RSEQ slightly accelerates the
scheduler:

Configuration: 2 sockets * 8-core Intel(R) Xeon(R) CPU E5-2630 v3 @
2.40GHz (directly on hardware, hyperthreading disabled in BIOS, energy
saving disabled in BIOS, turboboost disabled in BIOS, cpuidle.off=1
kernel parameter), with a Linux v4.6 defconfig+localyesconfig,
restartable sequences series applied.

* CONFIG_RSEQ=n

avg.:      41.37 s
std.dev.:   0.36 s

* CONFIG_RSEQ=y

avg.:      40.46 s
std.dev.:   0.33 s

- Size

On x86-64, between CONFIG_RSEQ=n/y, the text size increase of vmlinux is
567 bytes, and the data size increase of vmlinux is 5696 bytes.

[1] https://lwn.net/Articles/650333/
[2] http://www.linuxplumbersconf.org/2013/ocw/system/presentations/1695/original/LPC%20-%20PerCpu%20Atomics.pdf

Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Joel Fernandes <joelaf@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Watson <davejwatson@fb.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: "H . Peter Anvin" <hpa@zytor.com>
Cc: Chris Lameter <cl@linux.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Andrew Hunter <ahh@google.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: "Paul E . McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Paul Turner <pjt@google.com>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Ben Maurer <bmaurer@fb.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: linux-api@vger.kernel.org
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20151027235635.16059.11630.stgit@pjt-glaptop.roam.corp.google.com
Link: http://lkml.kernel.org/r/20150624222609.6116.86035.stgit@kitami.mtv.corp.google.com
Link: https://lkml.kernel.org/r/20180602124408.8430-3-mathieu.desnoyers@efficios.com
2018-06-06 11:58:31 +02:00
Richard Guy Briggs
c0b0ae8a87 audit: use inline function to set audit context
Recognizing that the audit context is an internal audit value, use an
access function to set the audit context pointer for the task
rather than reaching directly into the task struct to set it.

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: merge fuzz in audit.h]
Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-05-14 17:45:21 -04:00
Kees Cook
e01e80634e fork: unconditionally clear stack on fork
One of the classes of kernel stack content leaks[1] is exposing the
contents of prior heap or stack contents when a new process stack is
allocated.  Normally, those stacks are not zeroed, and the old contents
remain in place.  In the face of stack content exposure flaws, those
contents can leak to userspace.

Fixing this will make the kernel no longer vulnerable to these flaws, as
the stack will be wiped each time a stack is assigned to a new process.
There's not a meaningful change in runtime performance; it almost looks
like it provides a benefit.

Performing back-to-back kernel builds before:
	Run times: 157.86 157.09 158.90 160.94 160.80
	Mean: 159.12
	Std Dev: 1.54

and after:
	Run times: 159.31 157.34 156.71 158.15 160.81
	Mean: 158.46
	Std Dev: 1.46

Instead of making this a build or runtime config, Andy Lutomirski
recommended this just be enabled by default.

[1] A noisy search for many kinds of stack content leaks can be seen here:
https://cve.mitre.org/cgi-bin/cvekey.cgi?keyword=linux+kernel+stack+leak

I did some more with perf and cycle counts on running 100,000 execs of
/bin/true.

before:
Cycles: 218858861551 218853036130 214727610969 227656844122 224980542841
Mean:  221015379122.60
Std Dev: 4662486552.47

after:
Cycles: 213868945060 213119275204 211820169456 224426673259 225489986348
Mean:  217745009865.40
Std Dev: 5935559279.99

It continues to look like it's faster, though the deviation is rather
wide, but I'm not sure what I could do that would be less noisy.  I'm
open to ideas!

Link: http://lkml.kernel.org/r/20180221021659.GA37073@beast
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Laura Abbott <labbott@redhat.com>
Cc: Rasmus Villemoes <rasmus.villemoes@prevas.dk>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-20 17:18:35 -07:00
Mark Rutland
3eda69c92d kernel/fork.c: detect early free of a live mm
KASAN splats indicate that in some cases we free a live mm, then
continue to access it, with potentially disastrous results.  This is
likely due to a mismatched mmdrop() somewhere in the kernel, but so far
the culprit remains elusive.

Let's have __mmdrop() verify that the mm isn't live for the current
task, similar to the existing check for init_mm.  This way, we can catch
this class of issue earlier, and without requiring KASAN.

Currently, idle_task_exit() leaves active_mm stale after it switches to
init_mm.  This isn't harmful, but will trigger the new assertions, so we
must adjust idle_task_exit() to update active_mm.

Link: http://lkml.kernel.org/r/20180312140103.19235-1-mark.rutland@arm.com
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-04-05 21:36:27 -07:00
Dominik Brodowski
9b32105ec6 kernel: add ksys_unshare() helper; remove in-kernel calls to sys_unshare()
Using this helper allows us to avoid the in-kernel calls to the
sys_unshare() syscall. The ksys_ prefix denotes that this function is meant
as a drop-in replacement for the syscall. In particular, it uses the same
calling convention as sys_unshare().

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:16:06 +02:00
Dominik Brodowski
2de0db992d mm: use do_futex() instead of sys_futex() in mm_release()
sys_futex() is a wrapper to do_futex() which does not modify any
values here:

- uaddr, val and val3 are kept the same

- op is masked with FUTEX_CMD_MASK, but is always set to FUTEX_WAKE.
  Therefore, val2 is always 0.

- as utime is set to NULL, *timeout is NULL

This patch is part of a series which removes in-kernel calls to syscalls.
On this basis, the syscall entry path can be streamlined. For details, see
http://lkml.kernel.org/r/20180325162527.GA17492@light.dominikbrodowski.net

Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
2018-04-02 20:15:02 +02:00
Andrew Morton
d34bc48f82 include/linux/sched/mm.h: re-inline mmdrop()
As Peter points out, Doing a CALL+RET for just the decrement is a bit silly.

Fixes: d70f2a14b7 ("include/linux/sched/mm.h: uninline mmdrop_async(), etc")
Acked-by: Peter Zijlstra (Intel) <peterz@infraded.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-21 15:35:42 -08:00
Linus Torvalds
a2e5790d84 Merge branch 'akpm' (patches from Andrew)
Merge misc updates from Andrew Morton:

 - kasan updates

 - procfs

 - lib/bitmap updates

 - other lib/ updates

 - checkpatch tweaks

 - rapidio

 - ubsan

 - pipe fixes and cleanups

 - lots of other misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (114 commits)
  Documentation/sysctl/user.txt: fix typo
  MAINTAINERS: update ARM/QUALCOMM SUPPORT patterns
  MAINTAINERS: update various PALM patterns
  MAINTAINERS: update "ARM/OXNAS platform support" patterns
  MAINTAINERS: update Cortina/Gemini patterns
  MAINTAINERS: remove ARM/CLKDEV SUPPORT file pattern
  MAINTAINERS: remove ANDROID ION pattern
  mm: docs: add blank lines to silence sphinx "Unexpected indentation" errors
  mm: docs: fix parameter names mismatch
  mm: docs: fixup punctuation
  pipe: read buffer limits atomically
  pipe: simplify round_pipe_size()
  pipe: reject F_SETPIPE_SZ with size over UINT_MAX
  pipe: fix off-by-one error when checking buffer limits
  pipe: actually allow root to exceed the pipe buffer limits
  pipe, sysctl: remove pipe_proc_fn()
  pipe, sysctl: drop 'min' parameter from pipe-max-size converter
  kasan: rework Kconfig settings
  crash_dump: is_kdump_kernel can be boolean
  kernel/mutex: mutex_is_locked can be boolean
  ...
2018-02-06 22:15:42 -08:00
Marcos Paulo de Souza
667b60946e kernel/fork.c: add comment about usage of CLONE_FS flags and namespaces
All other places that deals with namespaces have an explanation of why
the restriction is there.

The description added in this commit was based on commit e66eded830
("userns: Don't allow CLONE_NEWUSER | CLONE_FS").

Link: http://lkml.kernel.org/r/20171112151637.13258-1-marcos.souza.org@gmail.com
Signed-off-by: Marcos Paulo de Souza <marcos.souza.org@gmail.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-06 18:32:45 -08:00