Commit Graph

22248 Commits

Author SHA1 Message Date
Linus Torvalds 17d25a337b Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Ingo Molnar:
 "This contains a single fix that fixes a nohz tick stopping bug when
  mixed-poliocy SCHED_FIFO and SCHED_RR tasks are present on a runqueue"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  nohz/full, sched/rt: Fix missed tick-reenabling bug in sched_can_stop_tick()
2016-05-06 11:53:27 -07:00
Linus Torvalds 83858a701c Chunyu Hu noticed that if one writes into the trigger files within the
ftrace subsystem of events that it can cause an oops. This file is only
 writable by root, but still is a bug that needs to be fixed.
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Merge tag 'trace-fixes-v4.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fix from Steven Rostedt:
 "Chunyu Hu noticed that if one writes into the trigger files within the
  ftrace subsystem of events that it can cause an oops.  This file is
  only writable by root, but still is a bug that needs to be fixed"

* tag 'trace-fixes-v4.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Don't display trigger file for events that can't be enabled
2016-05-03 18:02:38 -07:00
Chunyu Hu 854145e0a8 tracing: Don't display trigger file for events that can't be enabled
Currently register functions for events will be called
through the 'reg' field of event class directly without
any check when seting up triggers.

Triggers for events that don't support register through
debug fs (events under events/ftrace are for trace-cmd to
read event format, and most of them don't have a register
function except events/ftrace/functionx) can't be enabled
at all, and an oops will be hit when setting up trigger
for those events, so just not creating them is an easy way
to avoid the oops.

Link: http://lkml.kernel.org/r/1462275274-3911-1-git-send-email-chuhu@redhat.com

Cc: stable@vger.kernel.org # 3.14+
Fixes: 85f2b08268 ("tracing: Add basic event trigger framework")
Signed-off-by: Chunyu Hu <chuhu@redhat.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
2016-05-03 12:59:30 -04:00
Linus Torvalds 9c5d1bc2b7 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) MODULE_FIRMWARE firmware string not correct for iwlwifi 8000 chips,
    from Sara Sharon.

 2) Fix SKB size checks in batman-adv stack on receive, from Sven
    Eckelmann.

 3) Leak fix on mac80211 interface add error paths, from Johannes Berg.

 4) Cannot invoke napi_disable() with BH disabled in myri10ge driver,
    fix from Stanislaw Gruszka.

 5) Fix sign extension problem when computing feature masks in
    net_gso_ok(), from Marcelo Ricardo Leitner.

 6) lan78xx driver doesn't count packets and packet lengths in its
    statistics properly, fix from Woojung Huh.

 7) Fix the buffer allocation sizes in pegasus USB driver, from Petko
    Manolov.

 8) Fix refcount overflows in bpf, from Alexei Starovoitov.

 9) Unified dst cache handling introduced a preempt warning in
    ip_tunnel, fix by resetting rather then setting the cached route.
    From Paolo Abeni.

10) Listener hash collision test fix in soreuseport, from Craig Gallak

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (47 commits)
  gre: do not pull header in ICMP error processing
  net: Implement net_dbg_ratelimited() for CONFIG_DYNAMIC_DEBUG case
  tipc: only process unicast on intended node
  cxgb3: fix out of bounds read
  net/smscx5xx: use the device tree for mac address
  soreuseport: Fix TCP listener hash collision
  net: l2tp: fix reversed udp6 checksum flags
  ip_tunnel: fix preempt warning in ip tunnel creation/updating
  samples/bpf: fix trace_output example
  bpf: fix check_map_func_compatibility logic
  bpf: fix refcnt overflow
  drivers: net: cpsw: use of_phy_connect() in fixed-link case
  dt: cpsw: phy-handle, phy_id, and fixed-link are mutually exclusive
  drivers: net: cpsw: don't ignore phy-mode if phy-handle is used
  drivers: net: cpsw: fix segfault in case of bad phy-handle
  drivers: net: cpsw: fix parsing of phy-handle DT property in dual_emac config
  MAINTAINERS: net: Change maintainer for GRETH 10/100/1G Ethernet MAC device driver
  gre: reject GUE and FOU in collect metadata mode
  pegasus: fixes reported packet length
  pegasus: fixes URB buffer allocation size;
  ...
2016-05-02 09:40:42 -07:00
Linus Torvalds 1d003af2ef Merge branch 'akpm' (patches from Andrew)
Merge fixes from Andrew Morton:
 "20 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  Documentation/sysctl/vm.txt: update numa_zonelist_order description
  lib/stackdepot.c: allow the stack trace hash to be zero
  rapidio: fix potential NULL pointer dereference
  mm/memory-failure: fix race with compound page split/merge
  ocfs2/dlm: return zero if deref_done message is successfully handled
  Ananth has moved
  kcov: don't profile branches in kcov
  kcov: don't trace the code coverage code
  mm: wake kcompactd before kswapd's short sleep
  .mailmap: add Frank Rowand
  mm/hwpoison: fix wrong num_poisoned_pages accounting
  mm: call swap_slot_free_notify() with page lock held
  mm: vmscan: reclaim highmem zone if buffer_heads is over limit
  numa: fix /proc/<pid>/numa_maps for THP
  mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check
  mailmap: fix Krzysztof Kozlowski's misspelled name
  thp: keep huge zero page pinned until tlb flush
  mm: exclude HugeTLB pages from THP page_mapped() logic
  kexec: export OFFSET(page.compound_head) to find out compound tail page
  kexec: update VMCOREINFO for compound_order/dtor
2016-04-29 11:21:22 -07:00
Linus Torvalds 814dd9481d Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "x86 PMU driver fixes plus a core code race fix"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel: Fix incorrect lbr_sel_mask value
  perf/x86/intel/pt: Don't die on VMXON
  perf/core: Fix perf_event_open() vs. execve() race
  perf/x86/amd: Set the size of event map array to PERF_COUNT_HW_MAX
  perf/core: Make sysctl_perf_cpu_time_max_percent conform to documentation
  perf/x86/intel/rapl: Add missing Haswell model
  perf/x86/intel: Add model number for Skylake Server to perf
2016-04-28 20:19:04 -07:00
Linus Torvalds 2113caed87 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Two lockdep fixes"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix lock_chain::base size
  locking/lockdep: Fix ->irq_context calculation
2016-04-28 19:59:17 -07:00
Andrey Ryabinin 36f05ae8bc kcov: don't profile branches in kcov
Profiling 'if' statements in __sanitizer_cov_trace_pc() leads to
unbound recursion and crash:

	__sanitizer_cov_trace_pc() ->
		ftrace_likely_update ->
			__sanitizer_cov_trace_pc() ...

Define DISABLE_BRANCH_PROFILING to disable this tracer.

Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-28 19:34:04 -07:00
James Morse bdab42dfc9 kcov: don't trace the code coverage code
Kcov causes the compiler to add a call to __sanitizer_cov_trace_pc() in
every basic block.  Ftrace patches in a call to _mcount() to each
function it has annotated.

Letting these mechanisms annotate each other is a bad thing.  Break the
loop by adding 'notrace' to __sanitizer_cov_trace_pc() so that ftrace
won't try to patch this code.

This patch lets arm64 with KCOV and STACK_TRACER boot.

Signed-off-by: James Morse <james.morse@arm.com>
Acked-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-28 19:34:04 -07:00
Atsushi Kumagai d7f53518f7 kexec: export OFFSET(page.compound_head) to find out compound tail page
PageAnon() always look at head page to check PAGE_MAPPING_ANON and tail
page's page->mapping has just a poisoned data since commit 1c290f6421
("mm: sanitize page->mapping for tail pages").

If makedumpfile checks page->mapping of a compound tail page to
distinguish anonymous page as usual, it must fail in newer kernel.  So
it's necessary to export OFFSET(page.compound_head) to avoid checking
compound tail pages.

The problem is that unnecessary hugepages won't be removed from a dump
file in kernels 4.5.x and later.  This means that extra disk space would
be consumed.  It's a problem, but not critical.

Signed-off-by: Atsushi Kumagai <ats-kumagai@wm.jp.nec.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-28 19:34:04 -07:00
Atsushi Kumagai 8639a847b0 kexec: update VMCOREINFO for compound_order/dtor
makedumpfile refers page.lru.next to get the order of compound pages for
page filtering.

However, now the order is stored in page.compound_order, hence
VMCOREINFO should be updated to export the offset of
page.compound_order.

The fact is, page.compound_order was introduced already in kernel 4.0,
but the offset of it was the same as page.lru.next until kernel 4.3, so
this was not actual problem.

The above can be said also for page.lru.prev and page.compound_dtor,
it's necessary to detect hugetlbfs pages.  Further, the content was
changed from direct address to the ID which means dtor.

The problem is that unnecessary hugepages won't be removed from a dump
file in kernels 4.4.x and later.  This means that extra disk space would
be consumed.  It's a problem, but not critical.

Signed-off-by: Atsushi Kumagai <ats-kumagai@wm.jp.nec.com>
Acked-by: Dave Young <dyoung@redhat.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-28 19:34:04 -07:00
Alexei Starovoitov 6aff67c85c bpf: fix check_map_func_compatibility logic
The commit 35578d7984 ("bpf: Implement function bpf_perf_event_read() that get the selected hardware PMU conuter")
introduced clever way to check bpf_helper<->map_type compatibility.
Later on commit a43eec3042 ("bpf: introduce bpf_perf_event_output() helper") adjusted
the logic and inadvertently broke it.
Get rid of the clever bool compare and go back to two-way check
from map and from helper perspective.

Fixes: a43eec3042 ("bpf: introduce bpf_perf_event_output() helper")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28 17:29:45 -04:00
Alexei Starovoitov 92117d8443 bpf: fix refcnt overflow
On a system with >32Gbyte of phyiscal memory and infinite RLIMIT_MEMLOCK,
the malicious application may overflow 32-bit bpf program refcnt.
It's also possible to overflow map refcnt on 1Tb system.
Impose 32k hard limit which means that the same bpf program or
map cannot be shared by more than 32k processes.

Fixes: 1be7f75d16 ("bpf: enable non-root eBPF programs")
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-28 17:29:45 -04:00
Peter Zijlstra 79c9ce57eb perf/core: Fix perf_event_open() vs. execve() race
Jann reported that the ptrace_may_access() check in
find_lively_task_by_vpid() is racy against exec().

Specifically:

  perf_event_open()		execve()

  ptrace_may_access()
				commit_creds()
  ...				if (get_dumpable() != SUID_DUMP_USER)
				  perf_event_exit_task();
  perf_install_in_context()

would result in installing a counter across the creds boundary.

Fix this by wrapping lots of perf_event_open() in cred_guard_mutex.
This should be fine as perf_event_exit_task() is already called with
cred_guard_mutex held, so all perf locks already nest inside it.

Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28 10:32:41 +02:00
Peter Zijlstra 2548d546d4 nohz/full, sched/rt: Fix missed tick-reenabling bug in sched_can_stop_tick()
Chris Metcalf reported a that sched_can_stop_tick() sometimes fails to
re-enable the tick.

His observed problem is that rq->cfs.nr_running can be 1 even though
there are multiple runnable CFS tasks. This happens in the cgroup
case, in which case cfs.nr_running is the number of runnable entities
for that level.

If there is a single runnable cgroup (which can have an arbitrary
number of runnable child entries itself) rq->cfs.nr_running will be 1.

However, looking at that function I think there's more problems with it.

It seems to assume that if there's FIFO tasks, those will run. This is
incorrect. The FIFO task can have a lower prio than an RR task, in which
case the RR task will run.

So the whole fifo_nr_running test seems misplaced, it should go after
the rr_nr_running tests. That is, only if !rr_nr_running, can we use
fifo_nr_running like this.

Reported-by: Chris Metcalf <cmetcalf@mellanox.com>
Tested-by: Chris Metcalf <cmetcalf@mellanox.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Luiz Capitulino <lcapitulino@redhat.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Cc: Wanpeng Li <kernellwp@gmail.com>
Fixes: 76d92ac305 ("sched: Migrate sched to use new tick dependency mask model")
Link: http://lkml.kernel.org/r/20160421160315.GK24771@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-28 10:28:55 +02:00
Linus Torvalds b75a2bf899 Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fix from Tejun Heo:
 "So, it turns out we had a silly bug in the most fundamental part of
  workqueue for a very long time.  AFAICS, this dates back to pre-git
  era and has quite likely been there from the time workqueue was first
  introduced.

  A work item uses its PENDING bit to synchronize multiple queuers.
  Anyone who wins the PENDING bit owns the pending state of the work
  item.  Whether a queuer wins or loses the race, one thing should be
  guaranteed - there will soon be at least one execution of the work
  item - where "after" means that the execution instance would be able
  to see all the changes that the queuer has made prior to the queueing
  attempt.

  Unfortunately, we were missing a smp_mb() after clearing PENDING for
  execution, so nothing guaranteed visibility of the changes that a
  queueing loser has made, which manifested as a reproducible blk-mq
  stall.

  Lots of kudos to Roman for debugging the problem.  The patch for
  -stable is the minimal one.  For v3.7, Peter is working on a patch to
  make the code path slightly more efficient and less fragile"

* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: fix ghost PENDING flag while doing MQ IO
2016-04-27 12:03:59 -07:00
Linus Torvalds 763cfc86ee Merge branch 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fixes from Tejun Heo:
 "Two patches to fix a deadlock which can be easily triggered if memcg
  charge moving is used.

  This bug was introduced while converting threadgroup locking to a
  global percpu_rwsem and is caused by cgroup controller task migration
  path depending on the ability to create new kthreads.  cpuset had a
  similar issue which was fixed by performing heavy-lifting operations
  asynchronous to task migration.  The two patches fix the same issue in
  memcg in a similar way.  The first patch makes the mechanism generic
  and the second relocates memcg charge moving outside the migration
  path.

  Given that we don't want to perform heavy operations while
  writelocking threadgroup lock anyway, moving them out of the way is a
  desirable solution.  One thing to note is that the problem was
  difficult to debug because lockdep couldn't figure out the deadlock
  condition.  Looking into how to improve that"

* 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  memcg: relocate charge moving from ->attach to ->post_attach
  cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback
2016-04-27 11:41:14 -07:00
Linus Torvalds f28f20da70 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Handle v4/v6 mixed sockets properly in soreuseport, from Craig
    Gallak.

 2) Bug fixes for the new macsec facility (missing kmalloc NULL checks,
    missing locking around netdev list traversal, etc.) from Sabrina
    Dubroca.

 3) Fix handling of host routes on ifdown in ipv6, from David Ahern.

 4) Fix double-fdput in bpf verifier.  From Jann Horn.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (31 commits)
  bpf: fix double-fdput in replace_map_fd_with_map_ptr()
  net: ipv6: Delete host routes on an ifdown
  Revert "ipv6: Revert optional address flusing on ifdown."
  net/mlx4_en: fix spurious timestamping callbacks
  net: dummy: remove note about being Y by default
  cxgbi: fix uninitialized flowi6
  ipv6: Revert optional address flusing on ifdown.
  ipv4/fib: don't warn when primary address is missing if in_dev is dead
  net/mlx5: Add pci shutdown callback
  net/mlx5_core: Remove static from local variable
  net/mlx5e: Use vport MTU rather than physical port MTU
  net/mlx5e: Fix minimum MTU
  net/mlx5e: Device's mtu field is u16 and not int
  net/mlx5_core: Add ConnectX-5 to list of supported devices
  net/mlx5e: Fix MLX5E_100BASE_T define
  net/mlx5_core: Fix soft lockup in steering error flow
  qlcnic: Update version to 5.3.64
  net: stmmac: socfpga: Remove re-registration of reset controller
  macsec: fix netlink attribute validation
  macsec: add missing macsec prefix in uapi
  ...
2016-04-26 16:25:51 -07:00
Jann Horn 8358b02bf6 bpf: fix double-fdput in replace_map_fd_with_map_ptr()
When bpf(BPF_PROG_LOAD, ...) was invoked with a BPF program whose bytecode
references a non-map file descriptor as a map file descriptor, the error
handling code called fdput() twice instead of once (in __bpf_map_get() and
in replace_map_fd_with_map_ptr()). If the file descriptor table of the
current task is shared, this causes f_count to be decremented too much,
allowing the struct file to be freed while it is still in use
(use-after-free). This can be exploited to gain root privileges by an
unprivileged user.

This bug was introduced in
commit 0246e64d9a ("bpf: handle pseudo BPF_LD_IMM64 insn"), but is only
exploitable since
commit 1be7f75d16 ("bpf: enable non-root eBPF programs") because
previously, CAP_SYS_ADMIN was required to reach the vulnerable code.

(posted publicly according to request by maintainer)

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-26 17:37:21 -04:00
Roman Pen 346c09f804 workqueue: fix ghost PENDING flag while doing MQ IO
The bug in a workqueue leads to a stalled IO request in MQ ctx->rq_list
with the following backtrace:

[  601.347452] INFO: task kworker/u129:5:1636 blocked for more than 120 seconds.
[  601.347574]       Tainted: G           O    4.4.5-1-storage+ #6
[  601.347651] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[  601.348142] kworker/u129:5  D ffff880803077988     0  1636      2 0x00000000
[  601.348519] Workqueue: ibnbd_server_fileio_wq ibnbd_dev_file_submit_io_worker [ibnbd_server]
[  601.348999]  ffff880803077988 ffff88080466b900 ffff8808033f9c80 ffff880803078000
[  601.349662]  ffff880807c95000 7fffffffffffffff ffffffff815b0920 ffff880803077ad0
[  601.350333]  ffff8808030779a0 ffffffff815b01d5 0000000000000000 ffff880803077a38
[  601.350965] Call Trace:
[  601.351203]  [<ffffffff815b0920>] ? bit_wait+0x60/0x60
[  601.351444]  [<ffffffff815b01d5>] schedule+0x35/0x80
[  601.351709]  [<ffffffff815b2dd2>] schedule_timeout+0x192/0x230
[  601.351958]  [<ffffffff812d43f7>] ? blk_flush_plug_list+0xc7/0x220
[  601.352208]  [<ffffffff810bd737>] ? ktime_get+0x37/0xa0
[  601.352446]  [<ffffffff815b0920>] ? bit_wait+0x60/0x60
[  601.352688]  [<ffffffff815af784>] io_schedule_timeout+0xa4/0x110
[  601.352951]  [<ffffffff815b3a4e>] ? _raw_spin_unlock_irqrestore+0xe/0x10
[  601.353196]  [<ffffffff815b093b>] bit_wait_io+0x1b/0x70
[  601.353440]  [<ffffffff815b056d>] __wait_on_bit+0x5d/0x90
[  601.353689]  [<ffffffff81127bd0>] wait_on_page_bit+0xc0/0xd0
[  601.353958]  [<ffffffff81096db0>] ? autoremove_wake_function+0x40/0x40
[  601.354200]  [<ffffffff81127cc4>] __filemap_fdatawait_range+0xe4/0x140
[  601.354441]  [<ffffffff81127d34>] filemap_fdatawait_range+0x14/0x30
[  601.354688]  [<ffffffff81129a9f>] filemap_write_and_wait_range+0x3f/0x70
[  601.354932]  [<ffffffff811ced3b>] blkdev_fsync+0x1b/0x50
[  601.355193]  [<ffffffff811c82d9>] vfs_fsync_range+0x49/0xa0
[  601.355432]  [<ffffffff811cf45a>] blkdev_write_iter+0xca/0x100
[  601.355679]  [<ffffffff81197b1a>] __vfs_write+0xaa/0xe0
[  601.355925]  [<ffffffff81198379>] vfs_write+0xa9/0x1a0
[  601.356164]  [<ffffffff811c59d8>] kernel_write+0x38/0x50

The underlying device is a null_blk, with default parameters:

  queue_mode    = MQ
  submit_queues = 1

Verification that nullb0 has something inflight:

root@pserver8:~# cat /sys/block/nullb0/inflight
       0        1
root@pserver8:~# find /sys/block/nullb0/mq/0/cpu* -name rq_list -print -exec cat {} \;
...
/sys/block/nullb0/mq/0/cpu2/rq_list
CTX pending:
        ffff8838038e2400
...

During debug it became clear that stalled request is always inserted in
the rq_list from the following path:

   save_stack_trace_tsk + 34
   blk_mq_insert_requests + 231
   blk_mq_flush_plug_list + 281
   blk_flush_plug_list + 199
   wait_on_page_bit + 192
   __filemap_fdatawait_range + 228
   filemap_fdatawait_range + 20
   filemap_write_and_wait_range + 63
   blkdev_fsync + 27
   vfs_fsync_range + 73
   blkdev_write_iter + 202
   __vfs_write + 170
   vfs_write + 169
   kernel_write + 56

So blk_flush_plug_list() was called with from_schedule == true.

If from_schedule is true, that means that finally blk_mq_insert_requests()
offloads execution of __blk_mq_run_hw_queue() and uses kblockd workqueue,
i.e. it calls kblockd_schedule_delayed_work_on().

That means, that we race with another CPU, which is about to execute
__blk_mq_run_hw_queue() work.

Further debugging shows the following traces from different CPUs:

  CPU#0                                  CPU#1
  ----------------------------------     -------------------------------
  reqeust A inserted
  STORE hctx->ctx_map[0] bit marked
  kblockd_schedule...() returns 1
  <schedule to kblockd workqueue>
                                         request B inserted
                                         STORE hctx->ctx_map[1] bit marked
                                         kblockd_schedule...() returns 0
  *** WORK PENDING bit is cleared ***
  flush_busy_ctxs() is executed, but
  bit 1, set by CPU#1, is not observed

As a result request B pended forever.

This behaviour can be explained by speculative LOAD of hctx->ctx_map on
CPU#0, which is reordered with clear of PENDING bit and executed _before_
actual STORE of bit 1 on CPU#1.

The proper fix is an explicit full barrier <mfence>, which guarantees
that clear of PENDING bit is to be executed before all possible
speculative LOADS or STORES inside actual work function.

Signed-off-by: Roman Pen <roman.penyaev@profitbricks.com>
Cc: Gioh Kim <gi-oh.kim@profitbricks.com>
Cc: Michael Wang <yun.wang@profitbricks.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
2016-04-26 11:23:22 -04:00
Tejun Heo 5cf1cacb49 cgroup, cpuset: replace cpuset_post_attach_flush() with cgroup_subsys->post_attach callback
Since e93ad19d05 ("cpuset: make mm migration asynchronous"), cpuset
kicks off asynchronous NUMA node migration if necessary during task
migration and flushes it from cpuset_post_attach_flush() which is
called at the end of __cgroup_procs_write().  This is to avoid
performing migration with cgroup_threadgroup_rwsem write-locked which
can lead to deadlock through dependency on kworker creation.

memcg has a similar issue with charge moving, so let's convert it to
an official callback rather than the current one-off cpuset specific
function.  This patch adds cgroup_subsys->post_attach callback and
makes cpuset register cpuset_post_attach_flush() as its ->post_attach.

The conversion is mostly one-to-one except that the new callback is
called under cgroup_mutex.  This is to guarantee that no other
migration operations are started before ->post_attach callbacks are
finished.  cgroup_mutex is one of the outermost mutex in the system
and has never been and shouldn't be a problem.  We can add specialized
synchronization around __cgroup_procs_write() but I don't think
there's any noticeable benefit.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: <stable@vger.kernel.org> # 4.4+ prerequisite for the next patch
2016-04-25 15:45:14 -04:00
Linus Torvalds 82b23cb94b Merge branches 'perf-urgent-for-linus', 'smp-urgent-for-linus' and 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf, cpu hotplug and timer fixes from Ingo Molnar:
 "perf:
   - A single tooling fix for a user-triggerable segfault.

  CPU hotplug:
   - Fix a CPU hotplug corner case regression, introduced by the recent
     hotplug rework

  timers:
   - Fix a boot hang in the ARM based Tango SoC clocksource driver"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf intel-pt: Fix segfault tracing transactions

* 'smp-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Fix rollback during error-out in __cpu_disable()

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource/drivers/tango-xtal: Fix boot hang due to incorrect test
2016-04-23 11:45:52 -07:00
Linus Torvalds 0e11d25651 Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixes from Ingo Molnar:
 "Misc fixes:

  pvqspinlocks:
   - an instrumentation fix

  futexes:
   - preempt-count vs pagefault_disable decouple corner case fix
   - futex requeue plist race window fix
   - futex UNLOCK_PI transaction fix for a corner case"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  asm-generic/futex: Re-enable preemption in futex_atomic_cmpxchg_inatomic()
  futex: Acknowledge a new waiter in counter before plist
  futex: Handle unlock_pi race gracefully
  locking/pvqspinlock: Fix division by zero in qstat_read()
2016-04-23 11:39:48 -07:00
Linus Torvalds 16ecb41410 Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull irq fixes from Ingo Molnar:
 "A core irq affinity masks related fix and a MIPS irqchip driver fix"

* 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/mips-gic: Don't overrun pcpu_masks array
  genirq: Dont allow affinity mask to be updated on IPIs
2016-04-23 11:34:39 -07:00
Peter Zijlstra 75dd602a51 lockdep: Fix lock_chain::base size
lock_chain::base is used to store an index into the chain_hlocks[]
array, however that array contains more elements than can be indexed
using the u16.

Change the lock_chain structure to use a bitfield to encode the data
it needs and add BUILD_BUG_ON() assertions to check the fields are
wide enough.

Also, for DEBUG_LOCKDEP, assert that we don't run out of elements of
that array; as that would wreck the collision detectoring.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sedat Dilek <sedat.dilek@gmail.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160330093659.GS3408@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-23 13:53:03 +02:00
Boqun Feng c246975662 locking/lockdep: Fix ->irq_context calculation
task_irq_context() returns the encoded irq_context of the task, the
return value is encoded in the same as ->irq_context of held_lock.

Always return 0 if !(CONFIG_TRACE_IRQFLAGS && CONFIG_PROVE_LOCKING)

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Lai Jiangshan <jiangshanlai@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: sasha.levin@oracle.com
Link: http://lkml.kernel.org/r/1455602265-16490-2-git-send-email-boqun.feng@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-23 13:53:03 +02:00
Peter Zijlstra b303e7c15d perf/core: Make sysctl_perf_cpu_time_max_percent conform to documentation
Markus reported that 0 should also disable the throttling we per
Documentation/sysctl/kernel.txt.

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 91a612eea9 ("perf/core: Fix dynamic interrupt throttle")
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-23 13:47:50 +02:00
Sebastian Andrzej Siewior 3b9d6da67e cpu/hotplug: Fix rollback during error-out in __cpu_disable()
The recent introduction of the hotplug thread which invokes the callbacks on
the plugged cpu, cased the following regression:

If takedown_cpu() fails, then we run into several issues:

 1) The rollback of the target cpu states is not invoked. That leaves the smp
    threads and the hotplug thread in disabled state.

 2) notify_online() is executed due to a missing skip_onerr flag. That causes
    that both CPU_DOWN_FAILED and CPU_ONLINE notifications are invoked which
    confuses quite some notifiers.

 3) The CPU_DOWN_FAILED notification is not invoked on the target CPU. That's
    not an issue per se, but it is inconsistent and in consequence blocks the
    patches which rely on these states being invoked on the target CPU and not
    on the controlling cpu. It also does not preserve the strict call order on
    rollback which is problematic for the ongoing state machine conversion as
    well.

To fix this we add a rollback flag to the remote callback machinery and invoke
the rollback including the CPU_DOWN_FAILED notification on the remote
cpu. Further mark the notify online state with 'skip_onerr' so we don't get a
double invokation.

This workaround will go away once we moved the unplug invocation to the target
cpu itself.

[ tglx: Massaged changelog and moved the CPU_DOWN_FAILED notifiaction to the
  	target cpu ]

Fixes: 4cb28ced23 ("cpu/hotplug: Create hotplug threads")
Reported-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: linux-s390@vger.kernel.org
Cc: rt@linutronix.de
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Anna-Maria Gleixner <anna-maria@linutronix.de>
Link: http://lkml.kernel.org/r/20160408124015.GA21960@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-22 09:49:49 +02:00
Linus Torvalds c5edde3a81 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Fix memory leak in iwlwifi, from Matti Gottlieb.

 2) Add missing registration of netfilter arp_tables into initial
    namespace, from Florian Westphal.

 3) Fix potential NULL deref in DecNET routing code.

 4) Restrict NETLINK_URELEASE to truly bound sockets only, from Dmitry
    Ivanov.

 5) Fix dst ref counting in VRF, from David Ahern.

 6) Fix TSO segmenting limits in i40e driver, from Alexander Duyck.

 7) Fix heap leak in PACKET_DIAG_MCLIST, from Mathias Krause.

 8) Ravalidate IPV6 datagram socket cached routes properly, particularly
    with UDP, from Martin KaFai Lau.

 9) Fix endian bug in RDS dp_ack_seq handling, from Qing Huang.

10) Fix stats typing in bcmgenet driver, from Eric Dumazet.

11) Openvswitch needs to orphan SKBs before ipv6 fragmentation handing,
    from Joe Stringer.

12) SPI device reference leak in spi_ks8895 PHY driver, from Mark Brown.

13) atl2 doesn't actually support scatter-gather, so don't advertise the
    feature.  From Ben Hucthings.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (72 commits)
  openvswitch: use flow protocol when recalculating ipv6 checksums
  Driver: Vmxnet3: set CHECKSUM_UNNECESSARY for IPv6 packets
  atl2: Disable unimplemented scatter/gather feature
  net/mlx4_en: Split SW RX dropped counter per RX ring
  net/mlx4_core: Don't allow to VF change global pause settings
  net/mlx4_core: Avoid repeated calls to pci enable/disable
  net/mlx4_core: Implement pci_resume callback
  net: phy: spi_ks8895: Don't leak references to SPI devices
  net: ethernet: davinci_emac: Fix platform_data overwrite
  net: ethernet: davinci_emac: Fix Unbalanced pm_runtime_enable
  qede: Fix single MTU sized packet from firmware GRO flow
  qede: Fix setting Skb network header
  qede: Fix various memory allocation error flows for fastpath
  tcp: Merge tx_flags and tskey in tcp_shifted_skb
  tcp: Merge tx_flags and tskey in tcp_collapse_retrans
  drivers: net: cpsw: fix wrong regs access in cpsw_ndo_open
  tcp: Fix SOF_TIMESTAMPING_TX_ACK when handling dup acks
  openvswitch: Orphan skbs before IPv6 defrag
  Revert "Prevent NUll pointer dereference with two PHYs on cpsw"
  VSOCK: Only check error on skb_recv_datagram when skb is NULL
  ...
2016-04-21 12:57:34 -07:00
Matt Redfearn 4589f450fb genirq: Dont allow affinity mask to be updated on IPIs
The IPI domain re-purposes the IRQ affinity to signify the mask of CPUs
that this IPI will deliver to. This must not be modified before the IPI
is destroyed again, so set the IRQ_NO_BALANCING flag to prevent the
affinity being overwritten by setup_affinity().

Without this, if an IPI is reserved for a single target CPU, then
allocated using __setup_irq(), the affinity is overwritten with
cpu_online_mask. When ipi_destroy() is subsequently called on a
multi-cpu system, it will attempt to free cpumask_weight() IRQs
that were never allocated, and crash.

Fixes: d17bf24e69 ("genirq: Add a new generic IPI reservation code to irq core")
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: jason@lakedaemon.net
Cc: marc.zyngier@arm.com
Cc: ralf@linux-mips.org
Cc: Qais Yousef <qsyousef@gmail.com>
Cc: lisa.parratt@imgtec.com
Link: http://lkml.kernel.org/r/1461229712-13057-1-git-send-email-matt.redfearn@imgtec.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-21 12:05:15 +02:00
Davidlohr Bueso fe1bce9e21 futex: Acknowledge a new waiter in counter before plist
Otherwise an incoming waker on the dest hash bucket can miss
the waiter adding itself to the plist during the lockless
check optimization (small window but still the correct way
of doing this); similarly to the decrement counterpart.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: bigeasy@linutronix.de
Cc: dvhart@infradead.org
Cc: stable@kernel.org
Link: http://lkml.kernel.org/r/1461208164-29150-1-git-send-email-dave@stgolabs.net
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-21 11:06:09 +02:00
Sebastian Andrzej Siewior 89e9e66ba1 futex: Handle unlock_pi race gracefully
If userspace calls UNLOCK_PI unconditionally without trying the TID -> 0
transition in user space first then the user space value might not have the
waiters bit set. This opens the following race:

CPU0	    	      	    CPU1
uval = get_user(futex)
			    lock(hb)
lock(hb)
			    futex |= FUTEX_WAITERS
			    ....
			    unlock(hb)

cmpxchg(futex, uval, newval)

So the cmpxchg fails and returns -EINVAL to user space, which is wrong because
the futex value is valid.

To handle this (yes, yet another) corner case gracefully, check for a flag
change and retry.

[ tglx: Massaged changelog and slightly reworked implementation ]

Fixes: ccf9e6a80d ("futex: Make unlock_pi more robust")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: stable@vger.kernel.org
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Darren Hart <dvhart@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1460723739-5195-1-git-send-email-bigeasy@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-04-20 12:33:13 +02:00
Davidlohr Bueso 6687659568 locking/pvqspinlock: Fix division by zero in qstat_read()
While playing with the qstat statistics (in <debugfs>/qlockstat/) I ran into
the following splat on a VM when opening pv_hash_hops:

  divide error: 0000 [#1] SMP
  ...
  RIP: 0010:[<ffffffff810b61fe>]  [<ffffffff810b61fe>] qstat_read+0x12e/0x1e0
  ...
  Call Trace:
    [<ffffffff811cad7c>] ? mem_cgroup_commit_charge+0x6c/0xd0
    [<ffffffff8119750c>] ? page_add_new_anon_rmap+0x8c/0xd0
    [<ffffffff8118d3b9>] ? handle_mm_fault+0x1439/0x1b40
    [<ffffffff811937a9>] ? do_mmap+0x449/0x550
    [<ffffffff811d3de3>] ? __vfs_read+0x23/0xd0
    [<ffffffff811d4ab2>] ? rw_verify_area+0x52/0xd0
    [<ffffffff811d4bb1>] ? vfs_read+0x81/0x120
    [<ffffffff811d5f12>] ? SyS_read+0x42/0xa0
    [<ffffffff815720f6>] ? entry_SYSCALL_64_fastpath+0x1e/0xa8

Fix this by verifying that qstat_pv_kick_unlock is in fact non-zero,
similarly to what the qstat_pv_latency_wake case does, as if nothing
else, this can come from resetting the statistics, thus having 0 kicks
should be quite valid in this context.

Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Reviewed-by: Waiman Long <Waiman.Long@hpe.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dave@stgolabs.net
Cc: waiman.long@hpe.com
Link: http://lkml.kernel.org/r/1460961103-24953-1-git-send-email-dave@stgolabs.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-19 10:49:19 +02:00
Linus Torvalds ac82a57aff Merge branch 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fixlet from Ingo Molnar:
 "Fixes a build warning on certain Kconfig combinations"

* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Fix print_collision() unused warning
2016-04-16 15:43:19 -07:00
Linus Torvalds 51d7b12041 /proc/iomem: only expose physical resource addresses to privileged users
In commit c4004b02f8 ("x86: remove the kernel code/data/bss resources
from /proc/iomem") I was hoping to remove the phyiscal kernel address
data from /proc/iomem entirely, but that had to be reverted because some
system programs actually use it.

This limits all the detailed resource information to properly
credentialed users instead.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-14 12:56:09 -07:00
Alexei Starovoitov d82bccc690 bpf/verifier: reject invalid LD_ABS | BPF_DW instruction
verifier must check for reserved size bits in instruction opcode and
reject BPF_LD | BPF_ABS | BPF_DW and BPF_LD | BPF_IND | BPF_DW instructions,
otherwise interpreter will WARN_RATELIMIT on them during execution.

Fixes: ddd872bc30 ("bpf: verifier: add checks for BPF_ABS | BPF_IND instructions")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2016-04-14 01:31:50 -04:00
Linus Torvalds 4a2d057e4f Merge branch 'PAGE_CACHE_SIZE-removal'
Merge PAGE_CACHE_SIZE removal patches from Kirill Shutemov:
 "PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
  ago with promise that one day it will be possible to implement page
  cache with bigger chunks than PAGE_SIZE.

  This promise never materialized.  And unlikely will.

  Let's stop pretending that pages in page cache are special.  They are
  not.

  The first patch with most changes has been done with coccinelle.  The
  second is manual fixups on top.

  The third patch removes macros definition"

[ I was planning to apply this just before rc2, but then I spaced out,
  so here it is right _after_ rc2 instead.

  As Kirill suggested as a possibility, I could have decided to only
  merge the first two patches, and leave the old interfaces for
  compatibility, but I'd rather get it all done and any out-of-tree
  modules and patches can trivially do the converstion while still also
  working with older kernels, so there is little reason to try to
  maintain the redundant legacy model.    - Linus ]

* PAGE_CACHE_SIZE-removal:
  mm: drop PAGE_CACHE_* and page_cache_{get,release} definition
  mm, fs: remove remaining PAGE_CACHE_* and page_cache_{get,release} usage
  mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
2016-04-04 10:50:24 -07:00
Kirill A. Shutemov 09cbfeaf1a mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros
PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-04 10:41:08 -07:00
Borislav Petkov 5c8a010c24 locking/lockdep: Fix print_collision() unused warning
Fix this:

  kernel/locking/lockdep.c:2051:13: warning: ‘print_collision’ defined but not used [-Wunused-function]
  static void print_collision(struct task_struct *curr,
              ^

Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1459759327-2880-1-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-04-04 11:41:34 +02:00
Linus Torvalds 4c3b73c6a2 Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Ingo Molnar:
 "Misc kernel side fixes:

   - fix event leak
   - fix AMD PMU driver bug
   - fix core event handling bug
   - fix build bug on certain randconfigs

  Plus misc tooling fixes"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/amd/ibs: Fix pmu::stop() nesting
  perf/core: Don't leak event in the syscall error path
  perf/core: Fix time tracking bug with multiplexing
  perf jit: genelf makes assumptions about endian
  perf hists: Fix determination of a callchain node's childlessness
  perf tools: Add missing initialization of perf_sample.cpumode in synthesized samples
  perf tools: Fix build break on powerpc
  perf/x86: Move events_sysfs_show() outside CPU_SUP_INTEL
  perf bench: Fix detached tarball building due to missing 'perf bench memcpy' headers
  perf tests: Fix tarpkg build test error output redirection
2016-04-03 07:22:12 -05:00
Linus Torvalds 7b367f5dba Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core kernel fixes from Ingo Molnar:
 "This contains the nohz/atomic cleanup/fix for the fetch_or() ugliness
  you noted during the original nohz pull request, plus there's also
  misc fixes:

   - fix liblockdep build bug
   - fix uapi header build bug
   - print more lockdep hash collision info to help debug recent reports
     of hash collisions
   - update MAINTAINERS email address"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  MAINTAINERS: Update my email address
  locking/lockdep: Print chain_key collision information
  uapi/linux/stddef.h: Provide __always_inline to userspace headers
  tools/lib/lockdep: Fix unsupported 'basename -s' in run_tests.sh
  locking/atomic, sched: Unexport fetch_or()
  timers/nohz: Convert tick dependency mask to atomic_t
  locking/atomic: Introduce atomic_fetch_or()
2016-04-03 07:06:53 -05:00
Linus Torvalds 05cf8077e5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Missing device reference in IPSEC input path results in crashes
    during device unregistration.  From Subash Abhinov Kasiviswanathan.

 2) Per-queue ISR register writes not being done properly in macb
    driver, from Cyrille Pitchen.

 3) Stats accounting bugs in bcmgenet, from Patri Gynther.

 4) Lightweight tunnel's TTL and TOS were swapped in netlink dumps, from
    Quentin Armitage.

 5) SXGBE driver has off-by-one in probe error paths, from Rasmus
    Villemoes.

 6) Fix race in save/swap/delete options in netfilter ipset, from
    Vishwanath Pai.

 7) Ageing time of bridge not set properly when not operating over a
    switchdev device.  Fix from Haishuang Yan.

 8) Fix GRO regression wrt nested FOU/GUE based tunnels, from Alexander
    Duyck.

 9) IPV6 UDP code bumps wrong stats, from Eric Dumazet.

10) FEC driver should only access registers that actually exist on the
    given chipset, fix from Fabio Estevam.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (73 commits)
  net: mvneta: fix changing MTU when using per-cpu processing
  stmmac: fix MDIO settings
  Revert "stmmac: Fix 'eth0: No PHY found' regression"
  stmmac: fix TX normal DESC
  net: mvneta: use cache_line_size() to get cacheline size
  net: mvpp2: use cache_line_size() to get cacheline size
  net: mvpp2: fix maybe-uninitialized warning
  tun, bpf: fix suspicious RCU usage in tun_{attach, detach}_filter
  net: usb: cdc_ncm: adding Telit LE910 V2 mobile broadband card
  rtnl: fix msg size calculation in if_nlmsg_size()
  fec: Do not access unexisting register in Coldfire
  net: mvneta: replace MVNETA_CPU_D_CACHE_LINE_SIZE with L1_CACHE_BYTES
  net: mvpp2: replace MVPP2_CPU_D_CACHE_LINE_SIZE with L1_CACHE_BYTES
  net: dsa: mv88e6xxx: Clear the PDOWN bit on setup
  net: dsa: mv88e6xxx: Introduce _mv88e6xxx_phy_page_{read, write}
  bpf: make padding in bpf_tunnel_key explicit
  ipv6: udp: fix UDP_MIB_IGNOREDMULTI updates
  bnxt_en: Fix ethtool -a reporting.
  bnxt_en: Fix typo in bnxt_hwrm_set_pause_common().
  bnxt_en: Implement proper firmware message padding.
  ...
2016-04-01 20:03:33 -05:00
Alfredo Alvarez Fernandez 39e2e173fb locking/lockdep: Print chain_key collision information
A sequence of pairs [class_idx -> corresponding chain_key iteration]
is printed for both the current held_lock chain and the cached chain.

That exposes the two different class_idx sequences that led to that
particular hash value.

This helps with debugging hash chain collision reports.

Signed-off-by: Alfredo Alvarez Fernandez <alfredoalvarezfernandez@gmail.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-fsdevel@vger.kernel.org
Cc: sedat.dilek@gmail.com
Cc: tytso@mit.edu
Link: http://lkml.kernel.org/r/1459357416-19190-1-git-send-email-alfredoalvarezernandez@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31 15:03:58 +02:00
Alexander Shishkin 201c2f85bd perf/core: Don't leak event in the syscall error path
In the error path, event_file not being NULL is used to determine
whether the event itself still needs to be free'd, so fix it up to
avoid leaking.

Reported-by: Leon Yu <chianglungyu@gmail.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Fixes: 130056275a ("perf: Do not double free")
Link: http://lkml.kernel.org/r/87twk06yxp.fsf@ashishki-desk.ger.corp.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31 09:54:07 +02:00
Peter Zijlstra 8fdc65391c perf/core: Fix time tracking bug with multiplexing
Stephane reported that commit:

  3cbaa59069 ("perf: Fix ctx time tracking by introducing EVENT_TIME")

introduced a regression wrt. time tracking, as easily observed by:

> This patch introduce a bug in the time tracking of events when
> multiplexing is used.
>
> The issue is easily reproducible with the following perf run:
>
>  $ perf stat -a -C 0 -e branches,branches,branches,branches,branches,branches -I 1000
>      1.000730239            652,394      branches   (66.41%)
>      1.000730239            597,809      branches   (66.41%)
>      1.000730239            593,870      branches   (66.63%)
>      1.000730239            651,440      branches   (67.03%)
>      1.000730239            656,725      branches   (66.96%)
>      1.000730239      <not counted>      branches
>
> One branches event is shown as not having run. Yet, with
> multiplexing, all events should run especially with a 1s (-I 1000)
> interval. The delta for time_running comes out to 0. Yet, the event
> has run because the kernel is actually multiplexing the events. The
> problem is that the time tracking is the kernel and especially in
> ctx_sched_out() is wrong now.
>
> The problem is that in case that the kernel enters ctx_sched_out() with the
> following state:
>    ctx->is_active=0x7 event_type=0x1
>    Call Trace:
>     [<ffffffff813ddd41>] dump_stack+0x63/0x82
>     [<ffffffff81182bdc>] ctx_sched_out+0x2bc/0x2d0
>     [<ffffffff81183896>] perf_mux_hrtimer_handler+0xf6/0x2c0
>     [<ffffffff811837a0>] ? __perf_install_in_context+0x130/0x130
>     [<ffffffff810f5818>] __hrtimer_run_queues+0xf8/0x2f0
>     [<ffffffff810f6097>] hrtimer_interrupt+0xb7/0x1d0
>     [<ffffffff810509a8>] local_apic_timer_interrupt+0x38/0x60
>     [<ffffffff8175ca9d>] smp_apic_timer_interrupt+0x3d/0x50
>     [<ffffffff8175ac7c>] apic_timer_interrupt+0x8c/0xa0
>
> In that case, the test:
>       if (is_active & EVENT_TIME)
>
> will be false and the time will not be updated. Time must always be updated on
> sched out.

Fix this by always updating time if EVENT_TIME was set, as opposed to
only updating time when EVENT_TIME changed.

Reported-by: Stephane Eranian <eranian@google.com>
Tested-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vince Weaver <vincent.weaver@maine.edu>
Cc: kan.liang@intel.com
Cc: namhyung@kernel.org
Fixes: 3cbaa59069 ("perf: Fix ctx time tracking by introducing EVENT_TIME")
Link: http://lkml.kernel.org/r/20160329072644.GB3408@twins.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-31 09:54:06 +02:00
Frederic Weisbecker 5529578a27 locking/atomic, sched: Unexport fetch_or()
This patch functionally reverts:

  5fd7a09cfb ("atomic: Export fetch_or()")

During the merge Linus observed that the generic version of fetch_or()
was messy:

  " This makes the ugly "fetch_or()" macro that the scheduler used
    internally a new generic helper, and does a bad job at it. "

  e23604edac Merge branch 'timers-nohz-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Now that we have introduced atomic_fetch_or(), fetch_or() is only used
by the scheduler in order to deal with thread_info flags which type
can vary across architectures.

Lets confine fetch_or() back to the scheduler so that we encourage
future users to use the more robust and well typed atomic_t version
instead.

While at it, fetch_or() gets robustified, pasting improvements from a
previous patch by Ingo Molnar that avoids needless expression
re-evaluations in the loop.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1458830281-4255-4-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29 11:52:11 +02:00
Frederic Weisbecker f009a7a767 timers/nohz: Convert tick dependency mask to atomic_t
The tick dependency mask was intially unsigned long because this is the
type on which clear_bit() operates on and fetch_or() accepts it.

But now that we have atomic_fetch_or(), we can instead use
atomic_andnot() to clear the bit. This consolidates the type of our
tick dependency mask, reduce its size on structures and benefit from
possible architecture optimizations on atomic_t operations.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1458830281-4255-3-git-send-email-fweisbec@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-03-29 11:52:11 +02:00
Alexander Potapenko be7635e728 arch, ftrace: for KASAN put hard/soft IRQ entries into separate sections
KASAN needs to know whether the allocation happens in an IRQ handler.
This lets us strip everything below the IRQ entry point to reduce the
number of unique stack traces needed to be stored.

Move the definition of __irq_entry to <linux/interrupt.h> so that the
users don't need to pull in <linux/ftrace.h>.  Also introduce the
__softirq_entry macro which is similar to __irq_entry, but puts the
corresponding functions to the .softirqentry.text section.

Signed-off-by: Alexander Potapenko <glider@google.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Konstantin Serebryany <kcc@google.com>
Cc: Dmitry Chernenkov <dmitryc@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00
Michal Hocko 36324a990c oom: clear TIF_MEMDIE after oom_reaper managed to unmap the address space
When oom_reaper manages to unmap all the eligible vmas there shouldn't
be much of the freable memory held by the oom victim left anymore so it
makes sense to clear the TIF_MEMDIE flag for the victim and allow the
OOM killer to select another task.

The lack of TIF_MEMDIE also means that the victim cannot access memory
reserves anymore but that shouldn't be a problem because it would get
the access again if it needs to allocate and hits the OOM killer again
due to the fatal_signal_pending resp.  PF_EXITING check.  We can safely
hide the task from the OOM killer because it is clearly not a good
candidate anymore as everyhing reclaimable has been torn down already.

This patch will allow to cap the time an OOM victim can keep TIF_MEMDIE
and thus hold off further global OOM killer actions granted the oom
reaper is able to take mmap_sem for the associated mm struct.  This is
not guaranteed now but further steps should make sure that mmap_sem for
write should be blocked killable which will help to reduce such a lock
contention.  This is not done by this patch.

Note that exit_oom_victim might be called on a remote task from
__oom_reap_task now so we have to check and clear the flag atomically
otherwise we might race and underflow oom_victims or wake up waiters too
early.

Signed-off-by: Michal Hocko <mhocko@suse.com>
Suggested-by: Johannes Weiner <hannes@cmpxchg.org>
Suggested-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Andrea Argangeli <andrea@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00
Andrew Morton 69b27baf00 sched: add schedule_timeout_idle()
This will be needed in the patch "mm, oom: introduce oom reaper".

Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-03-25 16:37:42 -07:00