29990 Commits

Author SHA1 Message Date
Al Viro
cf6299b1d0 cgroup: stash cgroup_root reference into cgroup_fs_context
Note that this reference is *NOT* contributing to refcount of
cgroup_root in question and is valid only until cgroup_do_mount()
returns.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:32 -05:00
Al Viro
e34a98d5b2 cgroup2: switch to option-by-option parsing
[again, carved out of patch by dhowells]
[NB: we probably want to handle "source" in parse_param here]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:31 -05:00
Al Viro
8d2451f499 cgroup1: switch to option-by-option parsing
[dhowells should be the author - it's carved out of his patch]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:31 -05:00
Al Viro
f5dfb5315d cgroup: take options parsing into ->parse_monolithic()
Store the results in cgroup_fs_context.  There's a nasty twist caused
by the enabling/disabling subsystems - we can't do the checks sensitive
to that until cgroup_mutex gets grabbed.  Frankly, these checks are
complete bullshit (e.g. all,none combination is accepted if all subsystems
are disabled; so's cpusets,none and all,cpusets when cpusets is disabled,
etc.), but touching that would be a userland-visible behaviour change ;-/

So we do parsing in ->parse_monolithic() and have the consistency checks
done in check_cgroupfs_options(), with the latter called (on already parsed
options) from cgroup1_get_tree() and cgroup1_reconfigure().

Freeing the strdup'ed strings is done from fs_context destructor, which
somewhat simplifies the life for cgroup1_{get_tree,reconfigure}().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:30 -05:00
Al Viro
7feeef5869 cgroup: fold cgroup1_mount() into cgroup1_get_tree()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:30 -05:00
Al Viro
90129625d9 cgroup: start switching to fs_context
Unfortunately, cgroup is tangled into kernfs infrastructure.
To avoid converting all kernfs-based filesystems at once,
we need to untangle the remount part of things, instead of
having it go through kernfs_sop_remount_fs().  Fortunately,
it's not hard to do.

This commit just gets cgroup/cgroup1 to use fs_context to
deliver options on mount and remount paths.  Parsing those
is going to be done in the next commits; for now we do
pretty much what legacy case does.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28 03:29:29 -05:00
Ingo Molnar
c978b9460f perf/core improvements and fixes:
perf annotate:
 
   Wei Li:
 
   - Fix getting source line failure
 
 perf script:
 
   Andi Kleen:
 
   - Handle missing fields with -F +...
 
 perf data:
 
   Jiri Olsa:
 
   - Prep work to support per-cpu files in a directory.
 
 Intel PT:
 
   Adrian Hunter:
 
   - Improve thread_stack__no_call_return()
 
   - Hide x86 retpolines in thread stacks.
 
   - exported SQL viewer refactorings, new 'top calls' report..
 
   Alexander Shishkin:
 
   - Copy parent's address filter offsets on clone
 
   - Fix address filters for vmas with non-zero offset. Applies to
     ARM's CoreSight as well.
 
 python scripts:
 
   Tony Jones:
 
   - Python3 support for several 'perf script' python scripts.
 
 Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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Merge tag 'perf-core-for-mingo-5.1-20190225' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

perf annotate:

  Wei Li:

  - Fix getting source line failure

perf script:

  Andi Kleen:

  - Handle missing fields with -F +...

perf data:

  Jiri Olsa:

  - Prep work to support per-cpu files in a directory.

Intel PT:

  Adrian Hunter:

  - Improve thread_stack__no_call_return()

  - Hide x86 retpolines in thread stacks.

  - exported SQL viewer refactorings, new 'top calls' report..

  Alexander Shishkin:

  - Copy parent's address filter offsets on clone

  - Fix address filters for vmas with non-zero offset. Applies to
    ARM's CoreSight as well.

python scripts:

  Tony Jones:

  - Python3 support for several 'perf script' python scripts.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 08:29:50 +01:00
Ingo Molnar
9ed8f1a6e7 Merge branch 'linus' into perf/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 08:27:17 +01:00
Peter Zijlstra
72dcd505e8 locking/lockdep: Add module_param to enable consistency checks
And move the whole lot under CONFIG_DEBUG_LOCKDEP.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
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: Will Deacon <will.deacon@arm.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:50 +01:00
Bart Van Assche
669de8bda8 kernel/workqueue: Use dynamic lockdep keys for workqueues
The following commit:

  87915adc3f0a ("workqueue: re-add lockdep dependencies for flushing")

improved deadlock checking in the workqueue implementation. Unfortunately
that patch also introduced a few false positive lockdep complaints.

This patch suppresses these false positives by allocating the workqueue mutex
lockdep key dynamically.

An example of a false positive lockdep complaint suppressed by this patch
can be found below. The root cause of the lockdep complaint shown below
is that the direct I/O code can call alloc_workqueue() from inside a work
item created by another alloc_workqueue() call and that both workqueues
share the same lockdep key. This patch avoids that that lockdep complaint
is triggered by allocating the work queue lockdep keys dynamically.

In other words, this patch guarantees that a unique lockdep key is
associated with each work queue mutex.

  ======================================================
  WARNING: possible circular locking dependency detected
  4.19.0-dbg+ #1 Not tainted
  fio/4129 is trying to acquire lock:
  00000000a01cfe1a ((wq_completion)"dio/%s"sb->s_id){+.+.}, at: flush_workqueue+0xd0/0x970

  but task is already holding lock:
  00000000a0acecf9 (&sb->s_type->i_mutex_key#14){+.+.}, at: ext4_file_write_iter+0x154/0x710

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #2 (&sb->s_type->i_mutex_key#14){+.+.}:
         down_write+0x3d/0x80
         __generic_file_fsync+0x77/0xf0
         ext4_sync_file+0x3c9/0x780
         vfs_fsync_range+0x66/0x100
         dio_complete+0x2f5/0x360
         dio_aio_complete_work+0x1c/0x20
         process_one_work+0x481/0x9f0
         worker_thread+0x63/0x5a0
         kthread+0x1cf/0x1f0
         ret_from_fork+0x24/0x30

  -> #1 ((work_completion)(&dio->complete_work)){+.+.}:
         process_one_work+0x447/0x9f0
         worker_thread+0x63/0x5a0
         kthread+0x1cf/0x1f0
         ret_from_fork+0x24/0x30

  -> #0 ((wq_completion)"dio/%s"sb->s_id){+.+.}:
         lock_acquire+0xc5/0x200
         flush_workqueue+0xf3/0x970
         drain_workqueue+0xec/0x220
         destroy_workqueue+0x23/0x350
         sb_init_dio_done_wq+0x6a/0x80
         do_blockdev_direct_IO+0x1f33/0x4be0
         __blockdev_direct_IO+0x79/0x86
         ext4_direct_IO+0x5df/0xbb0
         generic_file_direct_write+0x119/0x220
         __generic_file_write_iter+0x131/0x2d0
         ext4_file_write_iter+0x3fa/0x710
         aio_write+0x235/0x330
         io_submit_one+0x510/0xeb0
         __x64_sys_io_submit+0x122/0x340
         do_syscall_64+0x71/0x220
         entry_SYSCALL_64_after_hwframe+0x49/0xbe

  other info that might help us debug this:

  Chain exists of:
    (wq_completion)"dio/%s"sb->s_id --> (work_completion)(&dio->complete_work) --> &sb->s_type->i_mutex_key#14

   Possible unsafe locking scenario:

         CPU0                    CPU1
         ----                    ----
    lock(&sb->s_type->i_mutex_key#14);
                                 lock((work_completion)(&dio->complete_work));
                                 lock(&sb->s_type->i_mutex_key#14);
    lock((wq_completion)"dio/%s"sb->s_id);

   *** DEADLOCK ***

  1 lock held by fio/4129:
   #0: 00000000a0acecf9 (&sb->s_type->i_mutex_key#14){+.+.}, at: ext4_file_write_iter+0x154/0x710

  stack backtrace:
  CPU: 3 PID: 4129 Comm: fio Not tainted 4.19.0-dbg+ #1
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
  Call Trace:
   dump_stack+0x86/0xc5
   print_circular_bug.isra.32+0x20a/0x218
   __lock_acquire+0x1c68/0x1cf0
   lock_acquire+0xc5/0x200
   flush_workqueue+0xf3/0x970
   drain_workqueue+0xec/0x220
   destroy_workqueue+0x23/0x350
   sb_init_dio_done_wq+0x6a/0x80
   do_blockdev_direct_IO+0x1f33/0x4be0
   __blockdev_direct_IO+0x79/0x86
   ext4_direct_IO+0x5df/0xbb0
   generic_file_direct_write+0x119/0x220
   __generic_file_write_iter+0x131/0x2d0
   ext4_file_write_iter+0x3fa/0x710
   aio_write+0x235/0x330
   io_submit_one+0x510/0xeb0
   __x64_sys_io_submit+0x122/0x340
   do_syscall_64+0x71/0x220
   entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes.berg@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Link: https://lkml.kernel.org/r/20190214230058.196511-20-bvanassche@acm.org
[ Reworked the changelog a bit. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:47 +01:00
Bart Van Assche
108c14858b locking/lockdep: Add support for dynamic keys
A shortcoming of the current lockdep implementation is that it requires
lock keys to be allocated statically. That forces all instances of lock
objects that occur in a given data structure to share a lock key. Since
lock dependency analysis groups lock objects per key sharing lock keys
can cause false positive lockdep reports. Make it possible to avoid
such false positive reports by allowing lock keys to be allocated
dynamically. Require that dynamically allocated lock keys are
registered before use by calling lockdep_register_key(). Complain about
attempts to register the same lock key pointer twice without calling
lockdep_unregister_key() between successive registration calls.

The purpose of the new lock_keys_hash[] data structure that keeps
track of all dynamic keys is twofold:

  - Verify whether the lockdep_register_key() and lockdep_unregister_key()
    functions are used correctly.

  - Avoid that lockdep_init_map() complains when encountering a dynamically
    allocated key.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-19-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:47 +01:00
Bart Van Assche
4bf5086218 locking/lockdep: Verify whether lock objects are small enough to be used as class keys
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-18-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:46 +01:00
Bart Van Assche
b526b2e39a locking/lockdep: Check data structure consistency
Debugging lockdep data structure inconsistencies is challenging. Add
code that verifies data structure consistency at runtime. That code is
disabled by default because it is very CPU intensive.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-17-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:45 +01:00
Bart Van Assche
de4643a773 locking/lockdep: Reuse lock chains that have been freed
A previous patch introduced a lock chain leak. Fix that leak by reusing
lock chains that have been freed.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-16-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:45 +01:00
Bart Van Assche
527af3ea27 locking/lockdep: Fix a comment in add_chain_cache()
Reflect that add_chain_cache() is always called with the graph lock held.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-15-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:45 +01:00
Bart Van Assche
2212684adf locking/lockdep: Introduce lockdep_next_lockchain() and lock_chain_count()
This patch does not change any functionality but makes the next patch in
this series easier to read.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-14-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:44 +01:00
Bart Van Assche
ace35a7ac4 locking/lockdep: Reuse list entries that are no longer in use
Instead of abandoning elements of list_entries[] that are no longer in
use, make alloc_list_entry() reuse array elements that have been freed.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-13-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:44 +01:00
Bart Van Assche
a0b0fd53e1 locking/lockdep: Free lock classes that are no longer in use
Instead of leaving lock classes that are no longer in use in the
lock_classes array, reuse entries from that array that are no longer in
use. Maintain a linked list of free lock classes with list head
'free_lock_class'. Only add freed lock classes to the free_lock_classes
list after a grace period to avoid that a lock_classes[] element would
be reused while an RCU reader is accessing it. Since the lockdep
selftests run in a context where sleeping is not allowed and since the
selftests require that lock resetting/zapping works with debug_locks
off, make the behavior of lockdep_free_key_range() and
lockdep_reset_lock() depend on whether or not these are called from
the context of the lockdep selftests.

Thanks to Peter for having shown how to modify get_pending_free()
such that that function does not have to sleep.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-12-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:43 +01:00
Bart Van Assche
29fc33fb72 locking/lockdep: Update two outdated comments
synchronize_sched() has been removed recently. Update the comments that
refer to synchronize_sched().

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Fixes: 51959d85f32d ("lockdep: Replace synchronize_sched() with synchronize_rcu()") # v5.0-rc1
Link: https://lkml.kernel.org/r/20190214230058.196511-11-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:43 +01:00
Bart Van Assche
cdc84d7949 locking/lockdep: Make it easy to detect whether or not inside a selftest
The patch that frees unused lock classes will modify the behavior of
lockdep_free_key_range() and lockdep_reset_lock() depending on whether
or not these functions are called from the context of the lockdep
selftests. Hence make it easy to detect whether or not lockdep code
is called from the context of a lockdep selftest.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-10-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:43 +01:00
Bart Van Assche
956f3563a8 locking/lockdep: Split lockdep_free_key_range() and lockdep_reset_lock()
This patch does not change the behavior of these functions but makes the
patch that frees unused lock classes easier to read.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-9-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:42 +01:00
Bart Van Assche
feb0a3865e locking/lockdep: Initialize the locks_before and locks_after lists earlier
This patch does not change any functionality. A later patch will reuse
lock classes that have been freed. In combination with that patch this
patch wil have the effect of initializing lock class order lists once
instead of every time a lock class structure is reinitialized.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-8-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:41 +01:00
Bart Van Assche
86cffb80a5 locking/lockdep: Make zap_class() remove all matching lock order entries
Make sure that all lock order entries that refer to a class are removed
from the list_entries[] array when a kernel module is unloaded.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-7-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:40 +01:00
Bart Van Assche
523b113bac locking/lockdep: Avoid that add_chain_cache() adds an invalid chain to the cache
Make sure that add_chain_cache() returns 0 and does not modify the
chain hash if nr_chain_hlocks == MAX_LOCKDEP_CHAIN_HLOCKS before this
function is called.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-5-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:40 +01:00
Bart Van Assche
15ea86b58c locking/lockdep: Fix reported required memory size (2/2)
Lock chains are only tracked with CONFIG_PROVE_LOCKING=y. Do not report
the memory required for the lock chain array if CONFIG_PROVE_LOCKING=n.
See also commit:

  ca58abcb4a6d ("lockdep: sanitise CONFIG_PROVE_LOCKING")

Include the size of the chain_hlocks[] array.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-4-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:39 +01:00
Bart Van Assche
7ff8517e10 locking/lockdep: Fix reported required memory size (1/2)
Change the sizeof(array element time) * (array size) expressions into
sizeof(array). This fixes the size computations of the classhash_table[]
and chainhash_table[] arrays.

The reason is that commit:

  a63f38cc4ccf ("locking/lockdep: Convert hash tables to hlists")

changed the type of the elements of that array from 'struct list_head' into
'struct hlist_head'.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-3-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:39 +01:00
Bart Van Assche
09d75ecb12 locking/lockdep: Fix two 32-bit compiler warnings
Use %zu to format size_t instead of %lu to avoid that the compiler
complains about a mismatch between format specifier and argument on
32-bit systems.

Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
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: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: johannes.berg@intel.com
Cc: tj@kernel.org
Link: https://lkml.kernel.org/r/20190214230058.196511-2-bvanassche@acm.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:38 +01:00
Waiman Long
733000c7ff locking/qspinlock: Remove unnecessary BUG_ON() call
With the > 4 nesting levels case handled by the commit:

  d682b596d993 ("locking/qspinlock: Handle > 4 slowpath nesting levels")

the BUG_ON() call in encode_tail() will never actually be triggered.

Remove it.

Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will.deacon@arm.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>
Link: https://lkml.kernel.org/r/1551057253-3231-1-git-send-email-longman@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:55:38 +01:00
Ingo Molnar
0614621d89 Merge branch 'linus' into locking/core, to pick up fixes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2019-02-28 07:50:39 +01:00
Yonghong Song
a115d0ed72 bpf: set inner_map_meta->spin_lock_off correctly
Commit d83525ca62cf ("bpf: introduce bpf_spin_lock")
introduced bpf_spin_lock and the field spin_lock_off
in kernel internal structure bpf_map has the following
meaning:
  >=0 valid offset, <0 error

For every map created, the kernel will ensure
spin_lock_off has correct value.

Currently, bpf_map->spin_lock_off is not copied
from the inner map to the map_in_map inner_map_meta
during a map_in_map type map creation, so
inner_map_meta->spin_lock_off = 0.
This will give verifier wrong information that
inner_map has bpf_spin_lock and the bpf_spin_lock
is defined at offset 0. An access to offset 0
of a value pointer will trigger the following error:
   bpf_spin_lock cannot be accessed directly by load/store

This patch fixed the issue by copy inner map's spin_lock_off
value to inner_map_meta->spin_lock_off.

Fixes: d83525ca62cf ("bpf: introduce bpf_spin_lock")
Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-02-27 17:03:13 -08:00
Alexei Starovoitov
5f8f8b93ae bpf: expose program stats via bpf_prog_info
Return bpf program run_time_ns and run_cnt via bpf_prog_info

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-27 17:22:50 +01:00
Alexei Starovoitov
492ecee892 bpf: enable program stats
JITed BPF programs are indistinguishable from kernel functions, but unlike
kernel code BPF code can be changed often.
Typical approach of "perf record" + "perf report" profiling and tuning of
kernel code works just as well for BPF programs, but kernel code doesn't
need to be monitored whereas BPF programs do.
Users load and run large amount of BPF programs.
These BPF stats allow tools monitor the usage of BPF on the server.
The monitoring tools will turn sysctl kernel.bpf_stats_enabled
on and off for few seconds to sample average cost of the programs.
Aggregated data over hours and days will provide an insight into cost of BPF
and alarms can trigger in case given program suddenly gets more expensive.

The cost of two sched_clock() per program invocation adds ~20 nsec.
Fast BPF progs (like selftests/bpf/progs/test_pkt_access.c) will slow down
from ~10 nsec to ~30 nsec.
static_key minimizes the cost of the stats collection.
There is no measurable difference before/after this patch
with kernel.bpf_stats_enabled=0

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-27 17:22:50 +01:00
Masahiro Yamada
b303c6df80 kbuild: compute false-positive -Wmaybe-uninitialized cases in Kconfig
Since -Wmaybe-uninitialized was introduced by GCC 4.7, we have patched
various false positives:

 - commit e74fc973b6e5 ("Turn off -Wmaybe-uninitialized when building
   with -Os") turned off this option for -Os.

 - commit 815eb71e7149 ("Kbuild: disable 'maybe-uninitialized' warning
   for CONFIG_PROFILE_ALL_BRANCHES") turned off this option for
   CONFIG_PROFILE_ALL_BRANCHES

 - commit a76bcf557ef4 ("Kbuild: enable -Wmaybe-uninitialized warning
   for "make W=1"") turned off this option for GCC < 4.9
   Arnd provided more explanation in https://lkml.org/lkml/2017/3/14/903

I think this looks better by shifting the logic from Makefile to Kconfig.

Link: https://github.com/ClangBuiltLinux/linux/issues/350
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
2019-02-27 21:43:20 +09:00
Peng Sun
781e62823c bpf: decrease usercnt if bpf_map_new_fd() fails in bpf_map_get_fd_by_id()
In bpf/syscall.c, bpf_map_get_fd_by_id() use bpf_map_inc_not_zero()
to increase the refcount, both map->refcnt and map->usercnt. Then, if
bpf_map_new_fd() fails, should handle map->usercnt too.

Fixes: bd5f5f4ecb78 ("bpf: Add BPF_MAP_GET_FD_BY_ID")
Signed-off-by: Peng Sun <sironhide0null@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-26 19:08:30 +01:00
David S. Miller
70f3522614 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Three conflicts, one of which, for marvell10g.c is non-trivial and
requires some follow-up from Heiner or someone else.

The issue is that Heiner converted the marvell10g driver over to
use the generic c45 code as much as possible.

However, in 'net' a bug fix appeared which makes sure that a new
local mask (MDIO_AN_10GBT_CTRL_ADV_NBT_MASK) with value 0x01e0
is cleared.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-24 12:06:19 -08:00
Linus Torvalds
c4eb1e1852 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:
 "Hopefully the last pull request for this release. Fingers crossed:

   1) Only refcount ESP stats on full sockets, from Martin Willi.

   2) Missing barriers in AF_UNIX, from Al Viro.

   3) RCU protection fixes in ipv6 route code, from Paolo Abeni.

   4) Avoid false positives in untrusted GSO validation, from Willem de
      Bruijn.

   5) Forwarded mesh packets in mac80211 need more tailroom allocated,
      from Felix Fietkau.

   6) Use operstate consistently for linkup in team driver, from George
      Wilkie.

   7) ThunderX bug fixes from Vadim Lomovtsev. Mostly races between VF
      and PF code paths.

   8) Purge ipv6 exceptions during netdevice removal, from Paolo Abeni.

   9) nfp eBPF code gen fixes from Jiong Wang.

  10) bnxt_en firmware timeout fix from Michael Chan.

  11) Use after free in udp/udpv6 error handlers, from Paolo Abeni.

  12) Fix a race in x25_bind triggerable by syzbot, from Eric Dumazet"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  net: phy: realtek: Dummy IRQ calls for RTL8366RB
  tcp: repaired skbs must init their tso_segs
  net/x25: fix a race in x25_bind()
  net: dsa: Remove documentation for port_fdb_prepare
  Revert "bridge: do not add port to router list when receives query with source 0.0.0.0"
  selftests: fib_tests: sleep after changing carrier. again.
  net: set static variable an initial value in atl2_probe()
  net: phy: marvell10g: Fix Multi-G advertisement to only advertise 10G
  bpf, doc: add bpf list as secondary entry to maintainers file
  udp: fix possible user after free in error handler
  udpv6: fix possible user after free in error handler
  fou6: fix proto error handler argument type
  udpv6: add the required annotation to mib type
  mdio_bus: Fix use-after-free on device_register fails
  net: Set rtm_table to RT_TABLE_COMPAT for ipv6 for tables > 255
  bnxt_en: Wait longer for the firmware message response to complete.
  bnxt_en: Fix typo in firmware message timeout logic.
  nfp: bpf: fix ALU32 high bits clearance bug
  nfp: bpf: fix code-gen bug on BPF_ALU | BPF_XOR | BPF_K
  Documentation: networking: switchdev: Update port parent ID section
  ...
2019-02-24 09:28:26 -08:00
Thomas Gleixner
a324ca9cad irqchip updates for Linux 5.1
- Core pseudo-NMI handling code
 - Allow the default irq domain to be retrieved
 - A new interrupt controller for the Loongson LS1X platform
 - Affinity support for the SiFive PLIC
 - Better support for the iMX irqsteer driver
 - NUMA aware memory allocations for GICv3
 - A handful of other fixes (i8259, GICv3, PLIC)
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Merge tag 'irqchip-5.1' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core

Pull irqchip updates from Marc Zyngier

- Core pseudo-NMI handling code
- Allow the default irq domain to be retrieved
- A new interrupt controller for the Loongson LS1X platform
- Affinity support for the SiFive PLIC
- Better support for the iMX irqsteer driver
- NUMA aware memory allocations for GICv3
- A handful of other fixes (i8259, GICv3, PLIC)
2019-02-23 10:53:31 +01:00
David S. Miller
ea34a00364 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2019-02-23

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix a bug in BPF's LPM deletion logic to match correct prefix
   length, from Alban.

2) Fix AF_XDP teardown by not destroying umem prematurely as it
   is still needed till all outstanding skbs are freed, from Björn.

3) Fix unkillable BPF_PROG_TEST_RUN under preempt kernel by checking
   signal_pending() outside need_resched() condition which is never
   triggered there, from Stanislav.

4) Fix two nfp JIT bugs, one in code emission for K-based xor, and
   another one to explicitly clear upper bits in alu32, from Jiong.

5) Add bpf list address to maintainers file, from Daniel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-02-22 20:45:38 -08:00
Alexander Shishkin
c60f83b813 perf, pt, coresight: Fix address filters for vmas with non-zero offset
Currently, the address range calculation for file-based filters works as
long as the vma that maps the matching part of the object file starts
from offset zero into the file (vm_pgoff==0). Otherwise, the resulting
filter range would be off by vm_pgoff pages. Another related problem is
that in case of a partially matching vma, that is, a vma that matches
part of a filter region, the filter range size wouldn't be adjusted.

Fix the arithmetics around address filter range calculations, taking
into account vma offset, so that the entire calculation is done before
the filter configuration is passed to the PMU drivers instead of having
those drivers do the final bit of arithmetics.

Based on the patch by Adrian Hunter <adrian.hunter.intel.com>.

Reported-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Fixes: 375637bc5249 ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20190215115655.63469-3-alexander.shishkin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-02-22 16:52:07 -03:00
Alexander Shishkin
18736eef12 perf: Copy parent's address filter offsets on clone
When a child event is allocated in the inherit_event() path, the VMA
based filter offsets are not copied from the parent, even though the
address space mapping of the new task remains the same, which leads to
no trace for the new task until exec.

Reported-by: Mansour Alharthi <malharthi9@gatech.edu>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Fixes: 375637bc5249 ("perf/core: Introduce address range filtering")
Link: http://lkml.kernel.org/r/20190215115655.63469-2-alexander.shishkin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-02-22 16:52:07 -03:00
Alban Crequy
7c0cdf0b39 bpf, lpm: fix lookup bug in map_delete_elem
trie_delete_elem() was deleting an entry even though it was not matching
if the prefixlen was correct. This patch adds a check on matchlen.

Reproducer:

$ sudo bpftool map create /sys/fs/bpf/mylpm type lpm_trie key 8 value 1 entries 128 name mylpm flags 1
$ sudo bpftool map update pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 aa bb cc dd value hex 01
$ sudo bpftool map dump pinned /sys/fs/bpf/mylpm
key: 10 00 00 00 aa bb cc dd  value: 01
Found 1 element
$ sudo bpftool map delete pinned /sys/fs/bpf/mylpm key hex 10 00 00 00 ff ff ff ff
$ echo $?
0
$ sudo bpftool map dump pinned /sys/fs/bpf/mylpm
Found 0 elements

A similar reproducer is added in the selftests.

Without the patch:

$ sudo ./tools/testing/selftests/bpf/test_lpm_map
test_lpm_map: test_lpm_map.c:485: test_lpm_delete: Assertion `bpf_map_delete_elem(map_fd, key) == -1 && errno == ENOENT' failed.
Aborted

With the patch: test_lpm_map runs without errors.

Fixes: e454cf595853 ("bpf: Implement map_delete_elem for BPF_MAP_TYPE_LPM_TRIE")
Cc: Craig Gallek <kraig@google.com>
Signed-off-by: Alban Crequy <alban@kinvolk.io>
Acked-by: Craig Gallek <kraig@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-22 16:17:53 +01:00
Alexei Starovoitov
e80d02dd76 seccomp, bpf: disable preemption before calling into bpf prog
All BPF programs must be called with preemption disabled.

Fixes: 568f196756ad ("bpf: check that BPF programs run with preemption disabled")
Reported-by: syzbot+8bf19ee2aa580de7a2a7@syzkaller.appspotmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-22 00:14:19 +01:00
Johannes Weiner
4e37504d1c psi: avoid divide-by-zero crash inside virtual machines
We've been seeing hard-to-trigger psi crashes when running inside VM
instances:

    divide error: 0000 [#1] SMP PTI
    Modules linked in: [...]
    CPU: 0 PID: 212 Comm: kworker/0:2 Not tainted 4.16.18-119_fbk9_3817_gfe944c98d695 #119
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
    Workqueue: events psi_clock
    RIP: 0010:psi_update_stats+0x270/0x490
    RSP: 0018:ffffc90001117e10 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff8800a35a13f8
    RDX: 0000000000000000 RSI: ffff8800a35a1340 RDI: 0000000000000000
    RBP: 0000000000000658 R08: ffff8800a35a1470 R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
    R13: 0000000000000000 R14: 0000000000000000 R15: 00000000000f8502
    FS:  0000000000000000(0000) GS:ffff88023fc00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 00007fbe370fa000 CR3: 00000000b1e3a000 CR4: 00000000000006f0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     psi_clock+0x12/0x50
     process_one_work+0x1e0/0x390
     worker_thread+0x2b/0x3c0
     ? rescuer_thread+0x330/0x330
     kthread+0x113/0x130
     ? kthread_create_worker_on_cpu+0x40/0x40
     ? SyS_exit_group+0x10/0x10
     ret_from_fork+0x35/0x40
    Code: 48 0f 47 c7 48 01 c2 45 85 e4 48 89 16 0f 85 e6 00 00 00 4c 8b 49 10 4c 8b 51 08 49 69 d9 f2 07 00 00 48 6b c0 64 4c 8b 29 31 d2 <48> f7 f7 49 69 d5 8d 06 00 00 48 89 c5 4c 69 f0 00 98 0b 00 48

The Code-line points to `period` being 0 inside update_stats(), and we
divide by that when calculating that period's pressure percentage.

The elapsed period should never be 0.  The reason this can happen is due
to an off-by-one in the idle time / missing period calculation combined
with a coarse sched_clock() in the virtual machine.

The target time for aggregation is advanced into the future on a fixed
grid to prevent clock drift.  So when an aggregation runs after some idle
period, we can not just set it to "now + psi_period", but have to
calculate the downtime and advance the target time relative to itself.

However, if the aggregator was disabled exactly one psi_period (ns), we
drop one idle period in the calculation due to a > when we should do >=.
In that case, next_update will be advanced from 'now - psi_period' to
'now' when it should be moved to 'now + psi_period'.  The run finishes
with last_update == next_update == sched_clock().

With hardware clocks, this exact nanosecond match isn't likely in the
first place; but if it does happen, the clock will still have moved on and
the period non-zero by the time the worker runs.  A pointlessly short
period, but besides the extra work, no harm no foul.  However, a slow
sched_clock() like we have on VMs might not have advanced either by the
time the worker runs again.  And when we calculate the elapsed period, the
result, our pressure divisor, will be 0.  Ouch.

Fix this by correctly handling the situation when the elapsed time between
aggregation runs is precisely two periods, and advance the expiration
timestamp correctly to period into the future.

Link: http://lkml.kernel.org/r/20190214193157.15788-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Reported-by: Łukasz Siudut <lsiudut@fb.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-02-21 09:01:00 -08:00
Liu Song
8bdc620178 workqueue: fix typo in comment
qeueue/queue

Signed-off-by: Liu Song <liu.song11@zte.com.cn>
Signed-off-by: Tejun Heo <tj@kernel.org>
2019-02-21 08:03:38 -08:00
Jann Horn
83540fbc88 tracing/perf: Use strndup_user() instead of buggy open-coded version
The first version of this method was missing the check for
`ret == PATH_MAX`; then such a check was added, but it didn't call kfree()
on error, so there was still a small memory leak in the error case.
Fix it by using strndup_user() instead of open-coding it.

Link: http://lkml.kernel.org/r/20190220165443.152385-1-jannh@google.com

Cc: Ingo Molnar <mingo@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 0eadcc7a7bc0 ("perf/core: Fix perf_uprobe_init()")
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-21 10:35:10 -05:00
Michael Ellerman
d0055df0c9 Merge branch 'topic/dma' into next
Merge hch's big DMA rework series. This is in a topic branch in case he
wants to merge it to minimise conflicts.
2019-02-21 23:15:10 +11:00
Linus Walleij
3dda927fdb Merge branch 'ib-qcom-ssbi' into devel 2019-02-21 12:58:31 +01:00
Marc Zyngier
9f199dd34c irqdomain: Allow the default irq domain to be retrieved
The default irq domain allows legacy code to create irqdomain
mappings without having to track the domain it is allocating
from. Setting the default domain is a one shot, fire and forget
operation, and no effort was made to be able to retrieve this
information at a later point in time.

Newer irqdomain APIs (the hierarchical stuff) relies on both
the irqchip code to track the irqdomain it is allocating from,
as well as some form of firmware abstraction to easily identify
which piece of HW maps to which irq domain (DT, ACPI).

For systems without such firmware (or legacy platform that are
getting dragged into the 21st century), things are a bit harder.
For these cases (and these cases only!), let's provide a way
to retrieve the default domain, allowing the use of the v2 API
without having to resort to platform-specific hacks.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-02-21 10:32:28 +00:00
Tetsuo Handa
cbae05d32f printk: Pass caller information to log_store().
When thread1 called printk() which did not end with '\n', and then thread2
called printk() which ends with '\n' before thread1 calls pr_cont(), the
partial content saved into "struct cont" is flushed by thread2 despite the
partial content was generated by thread1. This leads to confusing output
as if the partial content was generated by thread2. Fix this problem by
passing correct caller information to log_store().

Before:

  [ T8533] abcdefghijklm
  [ T8533] ABCDEFGHIJKLMNOPQRSTUVWXYZ
  [ T8532] nopqrstuvwxyz
  [ T8532] abcdefghijklmnopqrstuvwxyz
  [ T8533] abcdefghijklm
  [ T8533] ABCDEFGHIJKLMNOPQRSTUVWXYZ
  [ T8532] nopqrstuvwxyz

After:

  [ T8507] abcdefghijklm
  [ T8508] ABCDEFGHIJKLMNOPQRSTUVWXYZ
  [ T8507] nopqrstuvwxyz
  [ T8507] abcdefghijklmnopqrstuvwxyz
  [ T8507] abcdefghijklm
  [ T8508] ABCDEFGHIJKLMNOPQRSTUVWXYZ
  [ T8507] nopqrstuvwxyz

Link: http://lkml.kernel.org/r/1550314773-8607-1-git-send-email-penguin-kernel@I-love.SAKURA.ne.jp
To: Dmitry Vyukov <dvyukov@google.com>
To: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
[pmladek: broke 80-column rule where it made more harm than good]
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-02-21 10:41:15 +01:00
Colin Ian King
9e5a36a337 tracing: Fix spelling mistake: "analagous" -> "analogous"
There is a spelling mistake in the mini-howto help text. Fix it.

Link: http://lkml.kernel.org/r/20190217223222.16479-1-colin.king@canonical.com

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-02-20 13:51:08 -05:00