Commit Graph

36331 Commits

Author SHA1 Message Date
Linus Torvalds
a15286c63d Locking changes for this cycle:
- Core locking & atomics:
 
      - Convert all architectures to ARCH_ATOMIC: move every
        architecture to ARCH_ATOMIC, then get rid of ARCH_ATOMIC
        and all the transitory facilities and #ifdefs.
 
        Much reduction in complexity from that series:
 
            63 files changed, 756 insertions(+), 4094 deletions(-)
 
      - Self-test enhancements
 
  - Futexes:
 
      - Add the new FUTEX_LOCK_PI2 ABI, which is a variant that
        doesn't set FLAGS_CLOCKRT (.e. uses CLOCK_MONOTONIC).
 
        [ The temptation to repurpose FUTEX_LOCK_PI's implicit
          setting of FLAGS_CLOCKRT & invert the flag's meaning
          to avoid having to introduce a new variant was
          resisted successfully. ]
 
      - Enhance futex self-tests
 
  - Lockdep:
 
      - Fix dependency path printouts
      - Optimize trace saving
      - Broaden & fix wait-context checks
 
  - Misc cleanups and fixes.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:

 - Core locking & atomics:

     - Convert all architectures to ARCH_ATOMIC: move every architecture
       to ARCH_ATOMIC, then get rid of ARCH_ATOMIC and all the
       transitory facilities and #ifdefs.

       Much reduction in complexity from that series:

           63 files changed, 756 insertions(+), 4094 deletions(-)

     - Self-test enhancements

 - Futexes:

     - Add the new FUTEX_LOCK_PI2 ABI, which is a variant that doesn't
       set FLAGS_CLOCKRT (.e. uses CLOCK_MONOTONIC).

       [ The temptation to repurpose FUTEX_LOCK_PI's implicit setting of
         FLAGS_CLOCKRT & invert the flag's meaning to avoid having to
         introduce a new variant was resisted successfully. ]

     - Enhance futex self-tests

 - Lockdep:

     - Fix dependency path printouts

     - Optimize trace saving

     - Broaden & fix wait-context checks

 - Misc cleanups and fixes.

* tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  locking/lockdep: Correct the description error for check_redundant()
  futex: Provide FUTEX_LOCK_PI2 to support clock selection
  futex: Prepare futex_lock_pi() for runtime clock selection
  lockdep/selftest: Remove wait-type RCU_CALLBACK tests
  lockdep/selftests: Fix selftests vs PROVE_RAW_LOCK_NESTING
  lockdep: Fix wait-type for empty stack
  locking/selftests: Add a selftest for check_irq_usage()
  lockding/lockdep: Avoid to find wrong lock dep path in check_irq_usage()
  locking/lockdep: Remove the unnecessary trace saving
  locking/lockdep: Fix the dep path printing for backwards BFS
  selftests: futex: Add futex compare requeue test
  selftests: futex: Add futex wait test
  seqlock: Remove trailing semicolon in macros
  locking/lockdep: Reduce LOCKDEP dependency list
  locking/lockdep,doc: Improve readability of the block matrix
  locking/atomics: atomic-instrumented: simplify ifdeffery
  locking/atomic: delete !ARCH_ATOMIC remnants
  locking/atomic: xtensa: move to ARCH_ATOMIC
  locking/atomic: sparc: move to ARCH_ATOMIC
  locking/atomic: sh: move to ARCH_ATOMIC
  ...
2021-06-28 11:45:29 -07:00
Linus Torvalds
b89c07dea1 A single ELF format fix for a section flags mismatch bug that breaks
kernel tooling such as kpatch-build.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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mergetag object d33b9035e1
 type commit
 tag objtool-core-2021-06-28
 tagger Ingo Molnar <mingo@kernel.org> 1624859477 +0200
 
 The biggest change in this cycle is the new code to handle
 and rewrite variable sized jump labels - which results in
 slightly tighter code generation in hot paths, through the
 use of short(er) NOPs.
 
 Also a number of cleanups and fixes, and a change to the
 generic include/linux/compiler.h to handle a s390 GCC quirk.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tags 'objtool-urgent-2021-06-28' and 'objtool-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fix and updates from Ingo Molnar:
 "An ELF format fix for a section flags mismatch bug that breaks kernel
  tooling such as kpatch-build.

  The biggest change in this cycle is the new code to handle and rewrite
  variable sized jump labels - which results in slightly tighter code
  generation in hot paths, through the use of short(er) NOPs.

  Also a number of cleanups and fixes, and a change to the generic
  include/linux/compiler.h to handle a s390 GCC quirk"

* tag 'objtool-urgent-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Don't make .altinstructions writable

* tag 'objtool-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Improve reloc hash size guestimate
  instrumentation.h: Avoid using inline asm operand modifiers
  compiler.h: Avoid using inline asm operand modifiers
  kbuild: Fix objtool dependency for 'OBJECT_FILES_NON_STANDARD_<obj> := n'
  objtool: Reflow handle_jump_alt()
  jump_label/x86: Remove unused JUMP_LABEL_NOP_SIZE
  jump_label, x86: Allow short NOPs
  objtool: Provide stats for jump_labels
  objtool: Rewrite jump_label instructions
  objtool: Decode jump_entry::key addend
  jump_label, x86: Emit short JMP
  jump_label: Free jump_entry::key bit1 for build use
  jump_label, x86: Add variable length patching support
  jump_label, x86: Introduce jump_entry_size()
  jump_label, x86: Improve error when we fail expected text
  jump_label, x86: Factor out the __jump_table generation
  jump_label, x86: Strip ASM jump_label support
  x86, objtool: Dont exclude arch/x86/realmode/
  objtool: Rewrite hashtable sizing
2021-06-28 11:35:55 -07:00
Linus Torvalds
c10383b3fb regulator: Updates for v5.14
The main core change this release is generic support for handling of
 hardware errors from Matti Vaittinen, including some small updates to
 the reboot and thermal code so we can share support for powering off the
 system if things are going wrong enough.  Otherwise this release we've
 mainly seen the addition of new drivers, including MT6359 which has
 pulled in some small changes from the MFD tree for build dependencies.
 
  - Support for controlling the trigger points for hardware error
    detection, and shared handlers for this.
  - Support for Maxim MAX8993, Mediatek MT6359 and MT6359P, Qualcomm
    PM8226 and SA8115P-ADP, and Sylergy TCS4526.
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Merge tag 'regulator-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator

Pull regulator updates from Mark Brown:
 "The main core change this release is generic support for handling of
  hardware errors from Matti Vaittinen, including some small updates to
  the reboot and thermal code so we can share support for powering off
  the system if things are going wrong enough.

  Otherwise this release we've mainly seen the addition of new drivers,
  including MT6359 which has pulled in some small changes from the MFD
  tree for build dependencies.

   - Support for controlling the trigger points for hardware error
     detection, and shared handlers for this.

   - Support for Maxim MAX8993, Mediatek MT6359 and MT6359P, Qualcomm
     PM8226 and SA8115P-ADP, and Sylergy TCS4526"

* tag 'regulator-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regulator: (91 commits)
  regulator: bd9576: Fix uninitializes variable may_have_irqs
  regulator: max8893: Select REGMAP_I2C to fix build error
  regulator: da9052: Ensure enough delay time for .set_voltage_time_sel
  regulator: mt6358: Fix vdram2 .vsel_mask
  regulator: hi6421v600: Fix setting wrong driver_data
  MAINTAINERS: Add reviewer for regulator irq_helpers
  regulator: bd9576: Fix the driver name in id table
  regulator: bd9576: Support error reporting
  regulator: bd9576 add FET ON-resistance for OCW
  regulator: add property parsing and callbacks to set protection limits
  regulator: IRQ based event/error notification helpers
  regulator: move rdev_print helpers to internal.h
  regulator: add warning flags
  thermal: Use generic HW-protection shutdown API
  reboot: Add hardware protection power-off
  regulator: Add protection limit properties
  regulator: hi6421v600: Fix setting idle mode
  regulator: Add MAX8893 bindings
  regulator: max8893: add regulator driver
  regulator: hi6421: Use correct variable type for regmap api val argument
  ...
2021-06-28 11:06:10 -07:00
Linus Torvalds
b4b27b9eed Revert "signal: Allow tasks to cache one sigqueue struct"
This reverts commits 4bad58ebc8 (and
399f8dd9a8, which tried to fix it).

I do not believe these are correct, and I'm about to release 5.13, so am
reverting them out of an abundance of caution.

The locking is odd, and appears broken.

On the allocation side (in __sigqueue_alloc()), the locking is somewhat
straightforward: it depends on sighand->siglock.  Since one caller
doesn't hold that lock, it further then tests 'sigqueue_flags' to avoid
the case with no locks held.

On the freeing side (in sigqueue_cache_or_free()), there is no locking
at all, and the logic instead depends on 'current' being a single
thread, and not able to race with itself.

To make things more exciting, there's also the data race between freeing
a signal and allocating one, which is handled by using WRITE_ONCE() and
READ_ONCE(), and being mutually exclusive wrt the initial state (ie
freeing will only free if the old state was NULL, while allocating will
obviously only use the value if it was non-NULL, so only one or the
other will actually act on the value).

However, while the free->alloc paths do seem mutually exclusive thanks
to just the data value dependency, it's not clear what the memory
ordering constraints are on it.  Could writes from the previous
allocation possibly be delayed and seen by the new allocation later,
causing logical inconsistencies?

So it's all very exciting and unusual.

And in particular, it seems that the freeing side is incorrect in
depending on "current" being single-threaded.  Yes, 'current' is a
single thread, but in the presense of asynchronous events even a single
thread can have data races.

And such asynchronous events can and do happen, with interrupts causing
signals to be flushed and thus free'd (for example - sending a
SIGCONT/SIGSTOP can happen from interrupt context, and can flush
previously queued process control signals).

So regardless of all the other questions about the memory ordering and
locking for this new cached allocation, the sigqueue_cache_or_free()
assumptions seem to be fundamentally incorrect.

It may be that people will show me the errors of my ways, and tell me
why this is all safe after all.  We can reinstate it if so.  But my
current belief is that the WRITE_ONCE() that sets the cached entry needs
to be a smp_store_release(), and the READ_ONCE() that finds a cached
entry needs to be a smp_load_acquire() to handle memory ordering
correctly.

And the sequence in sigqueue_cache_or_free() would need to either use a
lock or at least be interrupt-safe some way (perhaps by using something
like the percpu 'cmpxchg': it doesn't need to be SMP-safe, but like the
percpu operations it needs to be interrupt-safe).

Fixes: 399f8dd9a8 ("signal: Prevent sigqueue caching after task got released")
Fixes: 4bad58ebc8 ("signal: Allow tasks to cache one sigqueue struct")
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-27 13:32:54 -07:00
Hugh Dickins
fe19bd3dae mm, futex: fix shared futex pgoff on shmem huge page
If more than one futex is placed on a shmem huge page, it can happen
that waking the second wakes the first instead, and leaves the second
waiting: the key's shared.pgoff is wrong.

When 3.11 commit 13d60f4b6a ("futex: Take hugepages into account when
generating futex_key"), the only shared huge pages came from hugetlbfs,
and the code added to deal with its exceptional page->index was put into
hugetlb source.  Then that was missed when 4.8 added shmem huge pages.

page_to_pgoff() is what others use for this nowadays: except that, as
currently written, it gives the right answer on hugetlbfs head, but
nonsense on hugetlbfs tails.  Fix that by calling hugetlbfs-specific
hugetlb_basepage_index() on PageHuge tails as well as on head.

Yes, it's unconventional to declare hugetlb_basepage_index() there in
pagemap.h, rather than in hugetlb.h; but I do not expect anything but
page_to_pgoff() ever to need it.

[akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope]

Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com
Fixes: 800d8c63b2 ("shmem: add huge pages support")
Reported-by: Neel Natu <neelnatu@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Zhang Yi <wetpzy@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Darren Hart <dvhart@infradead.org>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-24 19:40:54 -07:00
Petr Mladek
5fa54346ca kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()
The system might hang with the following backtrace:

	schedule+0x80/0x100
	schedule_timeout+0x48/0x138
	wait_for_common+0xa4/0x134
	wait_for_completion+0x1c/0x2c
	kthread_flush_work+0x114/0x1cc
	kthread_cancel_work_sync.llvm.16514401384283632983+0xe8/0x144
	kthread_cancel_delayed_work_sync+0x18/0x2c
	xxxx_pm_notify+0xb0/0xd8
	blocking_notifier_call_chain_robust+0x80/0x194
	pm_notifier_call_chain_robust+0x28/0x4c
	suspend_prepare+0x40/0x260
	enter_state+0x80/0x3f4
	pm_suspend+0x60/0xdc
	state_store+0x108/0x144
	kobj_attr_store+0x38/0x88
	sysfs_kf_write+0x64/0xc0
	kernfs_fop_write_iter+0x108/0x1d0
	vfs_write+0x2f4/0x368
	ksys_write+0x7c/0xec

It is caused by the following race between kthread_mod_delayed_work()
and kthread_cancel_delayed_work_sync():

CPU0				CPU1

Context: Thread A		Context: Thread B

kthread_mod_delayed_work()
  spin_lock()
  __kthread_cancel_work()
     spin_unlock()
     del_timer_sync()
				kthread_cancel_delayed_work_sync()
				  spin_lock()
				  __kthread_cancel_work()
				    spin_unlock()
				    del_timer_sync()
				    spin_lock()

				  work->canceling++
				  spin_unlock
     spin_lock()
   queue_delayed_work()
     // dwork is put into the worker->delayed_work_list

   spin_unlock()

				  kthread_flush_work()
     // flush_work is put at the tail of the dwork

				    wait_for_completion()

Context: IRQ

  kthread_delayed_work_timer_fn()
    spin_lock()
    list_del_init(&work->node);
    spin_unlock()

BANG: flush_work is not longer linked and will never get proceed.

The problem is that kthread_mod_delayed_work() checks work->canceling
flag before canceling the timer.

A simple solution is to (re)check work->canceling after
__kthread_cancel_work().  But then it is not clear what should be
returned when __kthread_cancel_work() removed the work from the queue
(list) and it can't queue it again with the new @delay.

The return value might be used for reference counting.  The caller has
to know whether a new work has been queued or an existing one was
replaced.

The proper solution is that kthread_mod_delayed_work() will remove the
work from the queue (list) _only_ when work->canceling is not set.  The
flag must be checked after the timer is stopped and the remaining
operations can be done under worker->lock.

Note that kthread_mod_delayed_work() could remove the timer and then
bail out.  It is fine.  The other canceling caller needs to cancel the
timer as well.  The important thing is that the queue (list)
manipulation is done atomically under worker->lock.

Link: https://lkml.kernel.org/r/20210610133051.15337-3-pmladek@suse.com
Fixes: 9a6b06c8d9 ("kthread: allow to modify delayed kthread work")
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reported-by: Martin Liu <liumartin@google.com>
Cc: <jenhaochen@google.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-24 19:40:54 -07:00
Petr Mladek
34b3d53447 kthread_worker: split code for canceling the delayed work timer
Patch series "kthread_worker: Fix race between kthread_mod_delayed_work()
and kthread_cancel_delayed_work_sync()".

This patchset fixes the race between kthread_mod_delayed_work() and
kthread_cancel_delayed_work_sync() including proper return value
handling.

This patch (of 2):

Simple code refactoring as a preparation step for fixing a race between
kthread_mod_delayed_work() and kthread_cancel_delayed_work_sync().

It does not modify the existing behavior.

Link: https://lkml.kernel.org/r/20210610133051.15337-2-pmladek@suse.com
Signed-off-by: Petr Mladek <pmladek@suse.com>
Cc: <jenhaochen@google.com>
Cc: Martin Liu <liumartin@google.com>
Cc: Minchan Kim <minchan@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-24 19:40:54 -07:00
Linus Torvalds
7749b0337b Fix a memory leak in the recently introduced sigqueue cache.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull sigqueue cache fix from Ingo Molnar:
 "Fix a memory leak in the recently introduced sigqueue cache"

* tag 'core-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  signal: Prevent sigqueue caching after task got released
2021-06-24 09:06:19 -07:00
Linus Torvalds
666751701b A last minute cgroup bandwidth scheduling fix for a recently
introduced logic fail which triggered a kernel warning by
 LTP's cfs_bandwidth01.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Ingo Molnar:
 "A last minute cgroup bandwidth scheduling fix for a recently
  introduced logic fail which triggered a kernel warning by LTP's
  cfs_bandwidth01 test"

* tag 'sched-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Ensure that the CFS parent is added after unthrottling
2021-06-24 08:58:23 -07:00
Linus Torvalds
c0e457851f Address a number of objtool warnings that got reported.
No change in behavior intended, but code generation might be
 impacted by:
 
    1f008d46f1: ("x86: Always inline task_size_max()")
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'objtool-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull objtool fixes from Ingo Molnar:
 "Address a number of objtool warnings that got reported.

  No change in behavior intended, but code generation might be impacted
  by commit 1f008d46f1 ("x86: Always inline task_size_max()")"

* tag 'objtool-urgent-2021-06-24' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/lockdep: Improve noinstr vs errors
  x86: Always inline task_size_max()
  x86/xen: Fix noinstr fail in exc_xen_unknown_trap()
  x86/xen: Fix noinstr fail in xen_pv_evtchn_do_upcall()
  x86/entry: Fix noinstr fail in __do_fast_syscall_32()
  objtool/x86: Ignore __x86_indirect_alt_* symbols
2021-06-24 08:47:33 -07:00
Linus Torvalds
8fd2ed1c01 Merge branch 'stable/for-linus-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb fix from Konrad Rzeszutek Wilk:
 "A fix for the regression for the DMA operations where the offset was
  ignored and corruptions would appear.

  Going forward there will be a cleanups to make the offset and
  alignment logic more clearer and better test-cases to help with this"

* 'stable/for-linus-5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb:
  swiotlb: manipulate orig_addr when tlb_addr has offset
2021-06-23 09:04:07 -07:00
Mark Brown
7fb593cbd8
Merge remote-tracking branch 'regulator/for-5.14' into regulator-next 2021-06-23 16:56:31 +01:00
Mimi Zohar
0c18f29aae module: limit enabling module.sig_enforce
Irrespective as to whether CONFIG_MODULE_SIG is configured, specifying
"module.sig_enforce=1" on the boot command line sets "sig_enforce".
Only allow "sig_enforce" to be set when CONFIG_MODULE_SIG is configured.

This patch makes the presence of /sys/module/module/parameters/sig_enforce
dependent on CONFIG_MODULE_SIG=y.

Fixes: fda784e50a ("module: export module signature enforcement status")
Reported-by: Nayna Jain <nayna@linux.ibm.com>
Tested-by: Mimi Zohar <zohar@linux.ibm.com>
Tested-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-22 11:13:19 -07:00
Xiongwei Song
0e8a89d49d locking/lockdep: Correct the description error for check_redundant()
If there is no matched result, check_redundant() will return BFS_RNOMATCH.

Signed-off-by: Xiongwei Song <sxwjean@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lkml.kernel.org/r/20210618130230.123249-1-sxwjean@me.com
2021-06-22 16:42:09 +02:00
Thomas Gleixner
bf22a69768 futex: Provide FUTEX_LOCK_PI2 to support clock selection
The FUTEX_LOCK_PI futex operand uses a CLOCK_REALTIME based absolute
timeout since it was implemented, but it does not require that the
FUTEX_CLOCK_REALTIME flag is set, because that was introduced later.

In theory as none of the user space implementations can set the
FUTEX_CLOCK_REALTIME flag on this operand, it would be possible to
creatively abuse it and make the meaning invers, i.e. select CLOCK_REALTIME
when not set and CLOCK_MONOTONIC when set. But that's a nasty hackery.

Another option would be to have a new FUTEX_CLOCK_MONOTONIC flag only for
FUTEX_LOCK_PI, but that's also awkward because it does not allow libraries
to handle the timeout clock selection consistently.

So provide a new FUTEX_LOCK_PI2 operand which implements the timeout
semantics which the other operands use and leave FUTEX_LOCK_PI alone.

Reported-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210422194705.440773992@linutronix.de
2021-06-22 16:42:09 +02:00
Thomas Gleixner
e112c41341 futex: Prepare futex_lock_pi() for runtime clock selection
futex_lock_pi() is the only futex operation which cannot select the clock
for timeouts (CLOCK_MONOTONIC/CLOCK_REALTIME). That's inconsistent and
there is no particular reason why this cannot be supported.

This was overlooked when CLOCK_REALTIME_FLAG was introduced and
unfortunately not reported when the inconsistency was discovered in glibc.

Prepare the function and enforce the CLOCK_REALTIME_FLAG on FUTEX_LOCK_PI
so that a new FUTEX_LOCK_PI2 can implement it correctly.

Reported-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210422194705.338657741@linutronix.de
2021-06-22 16:42:08 +02:00
Peter Zijlstra
f8b298cc39 lockdep: Fix wait-type for empty stack
Even the very first lock can violate the wait-context check, consider
the various IRQ contexts.

Fixes: de8f5e4f2d ("lockdep: Introduce wait-type checks")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Joerg Roedel <jroedel@suse.de>
Link: https://lore.kernel.org/r/20210617190313.256987481@infradead.org
2021-06-22 16:42:08 +02:00
Boqun Feng
7b1f8c6179 lockding/lockdep: Avoid to find wrong lock dep path in check_irq_usage()
In the step #3 of check_irq_usage(), we seach backwards to find a lock
whose usage conflicts the usage of @target_entry1 on safe/unsafe.
However, we should only keep the irq-unsafe usage of @target_entry1 into
consideration, because it could be a case where a lock is hardirq-unsafe
but soft-safe, and in check_irq_usage() we find it because its
hardirq-unsafe could result into a hardirq-safe-unsafe deadlock, but
currently since we don't filter out the other usage bits, so we may find
a lock dependency path softirq-unsafe -> softirq-safe, which in fact
doesn't cause a deadlock. And this may cause misleading lockdep splats.

Fix this by only keeping LOCKF_ENABLED_IRQ_ALL bits when we try the
backwards search.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210618170110.3699115-4-boqun.feng@gmail.com
2021-06-22 16:42:07 +02:00
Boqun Feng
d4c157c7b1 locking/lockdep: Remove the unnecessary trace saving
In print_bad_irq_dependency(), save_trace() is called to set the ->trace
for @prev_root as the current call trace, however @prev_root corresponds
to the the held lock, which may not be acquired in current call trace,
therefore it's wrong to use save_trace() to set ->trace of @prev_root.
Moreover, with our adjustment of printing backwards dependency path, the
->trace of @prev_root is unncessary, so remove it.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210618170110.3699115-3-boqun.feng@gmail.com
2021-06-22 16:42:07 +02:00
Boqun Feng
69c7a5fb24 locking/lockdep: Fix the dep path printing for backwards BFS
We use the same code to print backwards lock dependency path as the
forwards lock dependency path, and this could result into incorrect
printing because for a backwards lock_list ->trace is not the call trace
where the lock of ->class is acquired.

Fix this by introducing a separate function on printing the backwards
dependency path. Also add a few comments about the printing while we are
at it.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210618170110.3699115-2-boqun.feng@gmail.com
2021-06-22 16:42:06 +02:00
Thomas Gleixner
399f8dd9a8 signal: Prevent sigqueue caching after task got released
syzbot reported a memory leak related to sigqueue caching.

The assumption that a task cannot cache a sigqueue after the signal handler
has been dropped and exit_task_sigqueue_cache() has been invoked turns out
to be wrong.

Such a task can still invoke release_task(other_task), which cleans up the
signals of 'other_task' and ends up in sigqueue_cache_or_free(), which in
turn will cache the signal because task->sigqueue_cache is NULL. That's
obviously bogus because nothing will free the cached signal of that task
anymore, so the cached item is leaked.

This happens when e.g. the last non-leader thread exits and reaps the
zombie leader.

Prevent this by setting tsk::sigqueue_cache to an error pointer value in
exit_task_sigqueue_cache() which forces any subsequent invocation of
sigqueue_cache_or_free() from that task to hand the sigqueue back to the
kmemcache.

Add comments to all relevant places.

Fixes: 4bad58ebc8 ("signal: Allow tasks to cache one sigqueue struct")
Reported-by: syzbot+0bac5fec63d4f399ba98@syzkaller.appspotmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/878s32g6j5.ffs@nanos.tec.linutronix.de
2021-06-22 15:55:41 +02:00
Rik van Riel
fdaba61ef8 sched/fair: Ensure that the CFS parent is added after unthrottling
Ensure that a CFS parent will be in the list whenever one of its children is also
in the list.

A warning on rq->tmp_alone_branch != &rq->leaf_cfs_rq_list has been
reported while running LTP test cfs_bandwidth01.

Odin Ugedal found the root cause:

	$ tree /sys/fs/cgroup/ltp/ -d --charset=ascii
	/sys/fs/cgroup/ltp/
	|-- drain
	`-- test-6851
	    `-- level2
		|-- level3a
		|   |-- worker1
		|   `-- worker2
		`-- level3b
		    `-- worker3

Timeline (ish):
- worker3 gets throttled
- level3b is decayed, since it has no more load
- level2 get throttled
- worker3 get unthrottled
- level2 get unthrottled
  - worker3 is added to list
  - level3b is not added to list, since nr_running==0 and is decayed

 [ Vincent Guittot: Rebased and updated to fix for the reported warning. ]

Fixes: a7b359fc6a ("sched/fair: Correctly insert cfs_rq's to list on unthrottle")
Reported-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Suggested-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Rik van Riel <riel@surriel.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Acked-by: Odin Ugedal <odin@uged.al>
Link: https://lore.kernel.org/r/20210621174330.11258-1-vincent.guittot@linaro.org
2021-06-22 14:06:57 +02:00
Peter Zijlstra
49faa77759 locking/lockdep: Improve noinstr vs errors
Better handle the failure paths.

  vmlinux.o: warning: objtool: debug_locks_off()+0x23: call to console_verbose() leaves .noinstr.text section
  vmlinux.o: warning: objtool: debug_locks_off()+0x19: call to __kasan_check_write() leaves .noinstr.text section

  debug_locks_off+0x19/0x40:
  instrument_atomic_write at include/linux/instrumented.h:86
  (inlined by) __debug_locks_off at include/linux/debug_locks.h:17
  (inlined by) debug_locks_off at lib/debug_locks.c:41

Fixes: 6eebad1ad3 ("lockdep: __always_inline more for noinstr")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210621120120.784404944@infradead.org
2021-06-22 13:56:43 +02:00
Bumyong Lee
5f89468e2f swiotlb: manipulate orig_addr when tlb_addr has offset
in case of driver wants to sync part of ranges with offset,
swiotlb_tbl_sync_single() copies from orig_addr base to tlb_addr with
offset and ends up with data mismatch.

It was removed from
"swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single",
but said logic has to be added back in.

From Linus's email:
"That commit which the removed the offset calculation entirely, because the old

        (unsigned long)tlb_addr & (IO_TLB_SIZE - 1)

was wrong, but instead of removing it, I think it should have just
fixed it to be

        (tlb_addr - mem->start) & (IO_TLB_SIZE - 1);

instead. That way the slot offset always matches the slot index calculation."

(Unfortunatly that broke NVMe).

The use-case that drivers are hitting is as follow:

1. Get dma_addr_t from dma_map_single()

dma_addr_t tlb_addr = dma_map_single(dev, vaddr, vsize, DMA_TO_DEVICE);

    |<---------------vsize------------->|
    +-----------------------------------+
    |                                   | original buffer
    +-----------------------------------+
  vaddr

 swiotlb_align_offset
     |<----->|<---------------vsize------------->|
     +-------+-----------------------------------+
     |       |                                   | swiotlb buffer
     +-------+-----------------------------------+
          tlb_addr

2. Do something
3. Sync dma_addr_t through dma_sync_single_for_device(..)

dma_sync_single_for_device(dev, tlb_addr + offset, size, DMA_TO_DEVICE);

  Error case.
    Copy data to original buffer but it is from base addr (instead of
  base addr + offset) in original buffer:

 swiotlb_align_offset
     |<----->|<- offset ->|<- size ->|
     +-------+-----------------------------------+
     |       |            |##########|           | swiotlb buffer
     +-------+-----------------------------------+
          tlb_addr

    |<- size ->|
    +-----------------------------------+
    |##########|                        | original buffer
    +-----------------------------------+
  vaddr

The fix is to copy the data to the original buffer and take into
account the offset, like so:

 swiotlb_align_offset
     |<----->|<- offset ->|<- size ->|
     +-------+-----------------------------------+
     |       |            |##########|           | swiotlb buffer
     +-------+-----------------------------------+
          tlb_addr

    |<- offset ->|<- size ->|
    +-----------------------------------+
    |            |##########|           | original buffer
    +-----------------------------------+
  vaddr

[One fix which was Linus's that made more sense to as it created a
symmetry would break NVMe. The reason for that is the:
 unsigned int offset = (tlb_addr - mem->start) & (IO_TLB_SIZE - 1);

would come up with the proper offset, but it would lose the
alignment (which this patch contains).]

Fixes: 16fc3cef33 ("swiotlb: don't modify orig_addr in swiotlb_tbl_sync_single")
Signed-off-by: Bumyong Lee <bumyong.lee@samsung.com>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reported-by: Dominique MARTINET <dominique.martinet@atmark-techno.com>
Reported-by: Horia Geantă <horia.geanta@nxp.com>
Tested-by: Horia Geantă <horia.geanta@nxp.com>
CC: stable@vger.kernel.org
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2021-06-21 08:59:02 -04:00
Matti Vaittinen
dfa19b1138
reboot: Add hardware protection power-off
There can be few cases when we need to shut-down the system in order to
protect the hardware. Currently this is done at least by the thermal core
when temperature raises over certain limit.

Some PMICs can also generate interrupts for example for over-current or
over-voltage, voltage drops, short-circuit, ... etc. On some systems
these are a sign of hardware failure and only thing to do is try to
protect the rest of the hardware by shutting down the system.

Add shut-down logic which can be used by all subsystems instead of
implementing the shutdown in each subsystem. The logic is stolen from
thermal_core with difference of using atomic_t instead of a mutex in
order to allow calls directly from IRQ context and changing the WARN()
to pr_emerg() as discussed here:
https://lore.kernel.org/lkml/YJuPwAZroVZ%2Fw633@alley/
and here:
https://lore.kernel.org/linux-iommu/20210331093104.383705-4-geert+renesas@glider.be/

Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/e83ec1ca9408f90c857ea9dcdc57b14d9037b03f.1622628333.git.matti.vaittinen@fi.rohmeurope.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2021-06-21 13:08:36 +01:00
Linus Torvalds
cba5e97280 - A single fix to restore fairness between control groups with equal priority
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Merge tag 'sched_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Borislav Petkov:
 "A single fix to restore fairness between control groups with equal
  priority"

* tag 'sched_urgent_for_v5.13_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Correctly insert cfs_rq's to list on unthrottle
2021-06-20 09:44:52 -07:00
Linus Torvalds
9ed13a17e3 Networking fixes for 5.13-rc7, including fixes from wireless, bpf,
bluetooth, netfilter and can.
 
 Current release - regressions:
 
  - mlxsw: spectrum_qdisc: Pass handle, not band number to find_class()
           to fix modifying offloaded qdiscs
 
  - lantiq: net: fix duplicated skb in rx descriptor ring
 
  - rtnetlink: fix regression in bridge VLAN configuration, empty info
               is not an error, bot-generated "fix" was not needed
 
  - libbpf: s/rx/tx/ typo on umem->rx_ring_setup_done to fix
            umem creation
 
 Current release - new code bugs:
 
  - ethtool: fix NULL pointer dereference during module EEPROM dump via
             the new netlink API
 
  - mlx5e: don't update netdev RQs with PTP-RQ, the special purpose queue
           should not be visible to the stack
 
  - mlx5e: select special PTP queue only for SKBTX_HW_TSTAMP skbs
 
  - mlx5e: verify dev is present in get devlink port ndo, avoid a panic
 
 Previous releases - regressions:
 
  - neighbour: allow NUD_NOARP entries to be force GCed
 
  - further fixes for fallout from reorg of WiFi locking
      (staging: rtl8723bs, mac80211, cfg80211)
 
  - skbuff: fix incorrect msg_zerocopy copy notifications
 
  - mac80211: fix NULL ptr deref for injected rate info
 
  - Revert "net/mlx5: Arm only EQs with EQEs" it may cause missed IRQs
 
 Previous releases - always broken:
 
  - bpf: more speculative execution fixes
 
  - netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local
 
  - udp: fix race between close() and udp_abort() resulting in a panic
 
  - fix out of bounds when parsing TCP options before packets
    are validated (in netfilter: synproxy, tc: sch_cake and mptcp)
 
  - mptcp: improve operation under memory pressure, add missing wake-ups
 
  - mptcp: fix double-lock/soft lookup in subflow_error_report()
 
  - bridge: fix races (null pointer deref and UAF) in vlan tunnel egress
 
  - ena: fix DMA mapping function issues in XDP
 
  - rds: fix memory leak in rds_recvmsg
 
 Misc:
 
  - vrf: allow larger MTUs
 
  - icmp: don't send out ICMP messages with a source address of 0.0.0.0
 
  - cdc_ncm: switch to eth%d interface naming
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.13-rc7, including fixes from wireless, bpf,
  bluetooth, netfilter and can.

  Current release - regressions:

   - mlxsw: spectrum_qdisc: Pass handle, not band number to find_class()
     to fix modifying offloaded qdiscs

   - lantiq: net: fix duplicated skb in rx descriptor ring

   - rtnetlink: fix regression in bridge VLAN configuration, empty info
     is not an error, bot-generated "fix" was not needed

   - libbpf: s/rx/tx/ typo on umem->rx_ring_setup_done to fix umem
     creation

  Current release - new code bugs:

   - ethtool: fix NULL pointer dereference during module EEPROM dump via
     the new netlink API

   - mlx5e: don't update netdev RQs with PTP-RQ, the special purpose
     queue should not be visible to the stack

   - mlx5e: select special PTP queue only for SKBTX_HW_TSTAMP skbs

   - mlx5e: verify dev is present in get devlink port ndo, avoid a panic

  Previous releases - regressions:

   - neighbour: allow NUD_NOARP entries to be force GCed

   - further fixes for fallout from reorg of WiFi locking (staging:
     rtl8723bs, mac80211, cfg80211)

   - skbuff: fix incorrect msg_zerocopy copy notifications

   - mac80211: fix NULL ptr deref for injected rate info

   - Revert "net/mlx5: Arm only EQs with EQEs" it may cause missed IRQs

  Previous releases - always broken:

   - bpf: more speculative execution fixes

   - netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local

   - udp: fix race between close() and udp_abort() resulting in a panic

   - fix out of bounds when parsing TCP options before packets are
     validated (in netfilter: synproxy, tc: sch_cake and mptcp)

   - mptcp: improve operation under memory pressure, add missing
     wake-ups

   - mptcp: fix double-lock/soft lookup in subflow_error_report()

   - bridge: fix races (null pointer deref and UAF) in vlan tunnel
     egress

   - ena: fix DMA mapping function issues in XDP

   - rds: fix memory leak in rds_recvmsg

  Misc:

   - vrf: allow larger MTUs

   - icmp: don't send out ICMP messages with a source address of 0.0.0.0

   - cdc_ncm: switch to eth%d interface naming"

* tag 'net-5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (139 commits)
  net: ethernet: fix potential use-after-free in ec_bhf_remove
  selftests/net: Add icmp.sh for testing ICMP dummy address responses
  icmp: don't send out ICMP messages with a source address of 0.0.0.0
  net: ll_temac: Avoid ndo_start_xmit returning NETDEV_TX_BUSY
  net: ll_temac: Fix TX BD buffer overwrite
  net: ll_temac: Add memory-barriers for TX BD access
  net: ll_temac: Make sure to free skb when it is completely used
  MAINTAINERS: add Guvenc as SMC maintainer
  bnxt_en: Call bnxt_ethtool_free() in bnxt_init_one() error path
  bnxt_en: Fix TQM fastpath ring backing store computation
  bnxt_en: Rediscover PHY capabilities after firmware reset
  cxgb4: fix wrong shift.
  mac80211: handle various extensible elements correctly
  mac80211: reset profile_periodicity/ema_ap
  cfg80211: avoid double free of PMSR request
  cfg80211: make certificate generation more robust
  mac80211: minstrel_ht: fix sample time check
  net: qed: Fix memcpy() overflow of qed_dcbx_params()
  net: cdc_eem: fix tx fixup skb leak
  net: hamradio: fix memory leak in mkiss_close
  ...
2021-06-18 18:55:29 -07:00
Linus Torvalds
89fec74203 Tracing fixes for 5.13:
- Have recordmcount check for valid st_shndx otherwise some archs may have
    invalid references for the mcount location.
 
  - Two fixes done for mapping pids to task names. Traces were not showing
    the names of tasks when they should have.
 
  - Fix to trace_clock_global() to prevent it from going backwards
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Merge tag 'trace-v5.13-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Have recordmcount check for valid st_shndx otherwise some archs may
   have invalid references for the mcount location.

 - Two fixes done for mapping pids to task names. Traces were not
   showing the names of tasks when they should have.

 - Fix to trace_clock_global() to prevent it from going backwards

* tag 'trace-v5.13-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Do no increment trace_clock_global() by one
  tracing: Do not stop recording comms if the trace file is being read
  tracing: Do not stop recording cmdlines when tracing is off
  recordmcount: Correct st_shndx handling
2021-06-18 10:57:09 -07:00
Linus Torvalds
0f4022a490 printk fixup for 5.13
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Merge tag 'printk-for-5.13-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fixup from Petr Mladek:
 "Fix misplaced EXPORT_SYMBOL(vsprintf)"

* tag 'printk-for-5.13-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: Move EXPORT_SYMBOL() closer to vprintk definition
2021-06-18 10:50:41 -07:00
Linus Torvalds
944293bcee Power management fix for 5.13-rc7
Remove recently added frequency invariance support from the CPPC
 cpufreq driver, because it has turned out to be problematic and it
 cannot be fixed properly on time for 5.13 (Viresh Kumar).
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Merge tag 'pm-5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
 "Remove recently added frequency invariance support from the CPPC
  cpufreq driver, because it has turned out to be problematic and it
  cannot be fixed properly on time for 5.13 (Viresh Kumar)"

* tag 'pm-5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "cpufreq: CPPC: Add support for frequency invariance"
2021-06-18 10:42:36 -07:00
Steven Rostedt (VMware)
89529d8b8f tracing: Do no increment trace_clock_global() by one
The trace_clock_global() tries to make sure the events between CPUs is
somewhat in order. A global value is used and updated by the latest read
of a clock. If one CPU is ahead by a little, and is read by another CPU, a
lock is taken, and if the timestamp of the other CPU is behind, it will
simply use the other CPUs timestamp.

The lock is also only taken with a "trylock" due to tracing, and strange
recursions can happen. The lock is not taken at all in NMI context.

In the case where the lock is not able to be taken, the non synced
timestamp is returned. But it will not be less than the saved global
timestamp.

The problem arises because when the time goes "backwards" the time
returned is the saved timestamp plus 1. If the lock is not taken, and the
plus one to the timestamp is returned, there's a small race that can cause
the time to go backwards!

	CPU0				CPU1
	----				----
				trace_clock_global() {
				    ts = clock() [ 1000 ]
				    trylock(clock_lock) [ success ]
				    global_ts = ts; [ 1000 ]

				    <interrupted by NMI>
 trace_clock_global() {
    ts = clock() [ 999 ]
    if (ts < global_ts)
	ts = global_ts + 1 [ 1001 ]

    trylock(clock_lock) [ fail ]

    return ts [ 1001]
 }
				    unlock(clock_lock);
				    return ts; [ 1000 ]
				}

 trace_clock_global() {
    ts = clock() [ 1000 ]
    if (ts < global_ts) [ false 1000 == 1000 ]

    trylock(clock_lock) [ success ]
    global_ts = ts; [ 1000 ]
    unlock(clock_lock)

    return ts; [ 1000 ]
 }

The above case shows to reads of trace_clock_global() on the same CPU, but
the second read returns one less than the first read. That is, time when
backwards, and this is not what is allowed by trace_clock_global().

This was triggered by heavy tracing and the ring buffer checker that tests
for the clock going backwards:

 Ring buffer clock went backwards: 20613921464 -> 20613921463
 ------------[ cut here ]------------
 WARNING: CPU: 2 PID: 0 at kernel/trace/ring_buffer.c:3412 check_buffer+0x1b9/0x1c0
 Modules linked in:
 [..]
 [CPU: 2]TIME DOES NOT MATCH expected:20620711698 actual:20620711697 delta:6790234 before:20613921463 after:20613921463
   [20613915818] PAGE TIME STAMP
   [20613915818] delta:0
   [20613915819] delta:1
   [20613916035] delta:216
   [20613916465] delta:430
   [20613916575] delta:110
   [20613916749] delta:174
   [20613917248] delta:499
   [20613917333] delta:85
   [20613917775] delta:442
   [20613917921] delta:146
   [20613918321] delta:400
   [20613918568] delta:247
   [20613918768] delta:200
   [20613919306] delta:538
   [20613919353] delta:47
   [20613919980] delta:627
   [20613920296] delta:316
   [20613920571] delta:275
   [20613920862] delta:291
   [20613921152] delta:290
   [20613921464] delta:312
   [20613921464] delta:0 TIME EXTEND
   [20613921464] delta:0

This happened more than once, and always for an off by one result. It also
started happening after commit aafe104aa9 was added.

Cc: stable@vger.kernel.org
Fixes: aafe104aa9 ("tracing: Restructure trace_clock_global() to never block")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-18 09:10:00 -04:00
Steven Rostedt (VMware)
4fdd595e4f tracing: Do not stop recording comms if the trace file is being read
A while ago, when the "trace" file was opened, tracing was stopped, and
code was added to stop recording the comms to saved_cmdlines, for mapping
of the pids to the task name.

Code has been added that only records the comm if a trace event occurred,
and there's no reason to not trace it if the trace file is opened.

Cc: stable@vger.kernel.org
Fixes: 7ffbd48d5c ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-18 09:10:00 -04:00
Steven Rostedt (VMware)
85550c83da tracing: Do not stop recording cmdlines when tracing is off
The saved_cmdlines is used to map pids to the task name, such that the
output of the tracing does not just show pids, but also gives a human
readable name for the task.

If the name is not mapped, the output looks like this:

    <...>-1316          [005] ...2   132.044039: ...

Instead of this:

    gnome-shell-1316    [005] ...2   132.044039: ...

The names are updated when tracing is running, but are skipped if tracing
is stopped. Unfortunately, this stops the recording of the names if the
top level tracer is stopped, and not if there's other tracers active.

The recording of a name only happens when a new event is written into a
ring buffer, so there is no need to test if tracing is on or not. If
tracing is off, then no event is written and no need to test if tracing is
off or not.

Remove the check, as it hides the names of tasks for events in the
instance buffers.

Cc: stable@vger.kernel.org
Fixes: 7ffbd48d5c ("tracing: Cache comms only after an event occurred")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-18 09:10:00 -04:00
Pingfan Liu
4f5aecdff2 crash_core, vmcoreinfo: append 'SECTION_SIZE_BITS' to vmcoreinfo
As mentioned in kernel commit 1d50e5d0c5 ("crash_core, vmcoreinfo:
Append 'MAX_PHYSMEM_BITS' to vmcoreinfo"), SECTION_SIZE_BITS in the
formula:

    #define SECTIONS_SHIFT    (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)

Besides SECTIONS_SHIFT, SECTION_SIZE_BITS is also used to calculate
PAGES_PER_SECTION in makedumpfile just like kernel.

Unfortunately, this arch-dependent macro SECTION_SIZE_BITS changes, e.g.
recently in kernel commit f0b13ee232 ("arm64/sparsemem: reduce
SECTION_SIZE_BITS").  But user space wants a stable interface to get
this info.  Such info is impossible to be deduced from a crashdump
vmcore.  Hence append SECTION_SIZE_BITS to vmcoreinfo.

Link: https://lkml.kernel.org/r/20210608103359.84907-1-kernelfans@gmail.com
Link: http://lists.infradead.org/pipermail/kexec/2021-June/022676.html
Signed-off-by: Pingfan Liu <kernelfans@gmail.com>
Acked-by: Baoquan He <bhe@redhat.com>
Cc: Bhupesh Sharma <bhupesh.sharma@linaro.org>
Cc: Kazuhito Hagio <k-hagio@ab.jp.nec.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Boris Petkov <bp@alien8.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: James Morse <james.morse@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Dave Anderson <anderson@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-16 09:24:42 -07:00
Punit Agrawal
6262e1b906 printk: Move EXPORT_SYMBOL() closer to vprintk definition
Commit 28e1745b9f ("printk: rename vprintk_func to vprintk") while
improving readability by removing vprintk indirection, inadvertently
placed the EXPORT_SYMBOL() for the newly renamed function at the end
of the file.

For reader sanity, and as is convention move the EXPORT_SYMBOL()
declaration just after the end of the function.

Fixes: 28e1745b9f ("printk: rename vprintk_func to vprintk")
Signed-off-by: Punit Agrawal <punitagrawal@gmail.com>
Acked-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20210614235635.887365-1-punitagrawal@gmail.com
2021-06-16 10:42:19 +02:00
Daniel Borkmann
9183671af6 bpf: Fix leakage under speculation on mispredicted branches
The verifier only enumerates valid control-flow paths and skips paths that
are unreachable in the non-speculative domain. And so it can miss issues
under speculative execution on mispredicted branches.

For example, a type confusion has been demonstrated with the following
crafted program:

  // r0 = pointer to a map array entry
  // r6 = pointer to readable stack slot
  // r9 = scalar controlled by attacker
  1: r0 = *(u64 *)(r0) // cache miss
  2: if r0 != 0x0 goto line 4
  3: r6 = r9
  4: if r0 != 0x1 goto line 6
  5: r9 = *(u8 *)(r6)
  6: // leak r9

Since line 3 runs iff r0 == 0 and line 5 runs iff r0 == 1, the verifier
concludes that the pointer dereference on line 5 is safe. But: if the
attacker trains both the branches to fall-through, such that the following
is speculatively executed ...

  r6 = r9
  r9 = *(u8 *)(r6)
  // leak r9

... then the program will dereference an attacker-controlled value and could
leak its content under speculative execution via side-channel. This requires
to mistrain the branch predictor, which can be rather tricky, because the
branches are mutually exclusive. However such training can be done at
congruent addresses in user space using different branches that are not
mutually exclusive. That is, by training branches in user space ...

  A:  if r0 != 0x0 goto line C
  B:  ...
  C:  if r0 != 0x0 goto line D
  D:  ...

... such that addresses A and C collide to the same CPU branch prediction
entries in the PHT (pattern history table) as those of the BPF program's
lines 2 and 4, respectively. A non-privileged attacker could simply brute
force such collisions in the PHT until observing the attack succeeding.

Alternative methods to mistrain the branch predictor are also possible that
avoid brute forcing the collisions in the PHT. A reliable attack has been
demonstrated, for example, using the following crafted program:

  // r0 = pointer to a [control] map array entry
  // r7 = *(u64 *)(r0 + 0), training/attack phase
  // r8 = *(u64 *)(r0 + 8), oob address
  // [...]
  // r0 = pointer to a [data] map array entry
  1: if r7 == 0x3 goto line 3
  2: r8 = r0
  // crafted sequence of conditional jumps to separate the conditional
  // branch in line 193 from the current execution flow
  3: if r0 != 0x0 goto line 5
  4: if r0 == 0x0 goto exit
  5: if r0 != 0x0 goto line 7
  6: if r0 == 0x0 goto exit
  [...]
  187: if r0 != 0x0 goto line 189
  188: if r0 == 0x0 goto exit
  // load any slowly-loaded value (due to cache miss in phase 3) ...
  189: r3 = *(u64 *)(r0 + 0x1200)
  // ... and turn it into known zero for verifier, while preserving slowly-
  // loaded dependency when executing:
  190: r3 &= 1
  191: r3 &= 2
  // speculatively bypassed phase dependency
  192: r7 += r3
  193: if r7 == 0x3 goto exit
  194: r4 = *(u8 *)(r8 + 0)
  // leak r4

As can be seen, in training phase (phase != 0x3), the condition in line 1
turns into false and therefore r8 with the oob address is overridden with
the valid map value address, which in line 194 we can read out without
issues. However, in attack phase, line 2 is skipped, and due to the cache
miss in line 189 where the map value is (zeroed and later) added to the
phase register, the condition in line 193 takes the fall-through path due
to prior branch predictor training, where under speculation, it'll load the
byte at oob address r8 (unknown scalar type at that point) which could then
be leaked via side-channel.

One way to mitigate these is to 'branch off' an unreachable path, meaning,
the current verification path keeps following the is_branch_taken() path
and we push the other branch to the verification stack. Given this is
unreachable from the non-speculative domain, this branch's vstate is
explicitly marked as speculative. This is needed for two reasons: i) if
this path is solely seen from speculative execution, then we later on still
want the dead code elimination to kick in in order to sanitize these
instructions with jmp-1s, and ii) to ensure that paths walked in the
non-speculative domain are not pruned from earlier walks of paths walked in
the speculative domain. Additionally, for robustness, we mark the registers
which have been part of the conditional as unknown in the speculative path
given there should be no assumptions made on their content.

The fix in here mitigates type confusion attacks described earlier due to
i) all code paths in the BPF program being explored and ii) existing
verifier logic already ensuring that given memory access instruction
references one specific data structure.

An alternative to this fix that has also been looked at in this scope was to
mark aux->alu_state at the jump instruction with a BPF_JMP_TAKEN state as
well as direction encoding (always-goto, always-fallthrough, unknown), such
that mixing of different always-* directions themselves as well as mixing of
always-* with unknown directions would cause a program rejection by the
verifier, e.g. programs with constructs like 'if ([...]) { x = 0; } else
{ x = 1; }' with subsequent 'if (x == 1) { [...] }'. For unprivileged, this
would result in only single direction always-* taken paths, and unknown taken
paths being allowed, such that the former could be patched from a conditional
jump to an unconditional jump (ja). Compared to this approach here, it would
have two downsides: i) valid programs that otherwise are not performing any
pointer arithmetic, etc, would potentially be rejected/broken, and ii) we are
required to turn off path pruning for unprivileged, where both can be avoided
in this work through pushing the invalid branch to the verification stack.

The issue was originally discovered by Adam and Ofek, and later independently
discovered and reported as a result of Benedict and Piotr's research work.

Fixes: b2157399cc ("bpf: prevent out-of-bounds speculation")
Reported-by: Adam Morrison <mad@cs.tau.ac.il>
Reported-by: Ofek Kirzner <ofekkir@gmail.com>
Reported-by: Benedict Schlueter <benedict.schlueter@rub.de>
Reported-by: Piotr Krysiuk <piotras@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-06-14 23:06:10 +02:00
Daniel Borkmann
fe9a5ca7e3 bpf: Do not mark insn as seen under speculative path verification
... in such circumstances, we do not want to mark the instruction as seen given
the goal is still to jmp-1 rewrite/sanitize dead code, if it is not reachable
from the non-speculative path verification. We do however want to verify it for
safety regardless.

With the patch as-is all the insns that have been marked as seen before the
patch will also be marked as seen after the patch (just with a potentially
different non-zero count). An upcoming patch will also verify paths that are
unreachable in the non-speculative domain, hence this extension is needed.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-06-14 23:06:06 +02:00
Daniel Borkmann
d203b0fd86 bpf: Inherit expanded/patched seen count from old aux data
Instead of relying on current env->pass_cnt, use the seen count from the
old aux data in adjust_insn_aux_data(), and expand it to the new range of
patched instructions. This change is valid given we always expand 1:n
with n>=1, so what applies to the old/original instruction needs to apply
for the replacement as well.

Not relying on env->pass_cnt is a prerequisite for a later change where we
want to avoid marking an instruction seen when verified under speculative
execution path.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: John Fastabend <john.fastabend@gmail.com>
Reviewed-by: Benedict Schlueter <benedict.schlueter@rub.de>
Reviewed-by: Piotr Krysiuk <piotras@gmail.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-06-14 23:06:00 +02:00
Odin Ugedal
a7b359fc6a sched/fair: Correctly insert cfs_rq's to list on unthrottle
Fix an issue where fairness is decreased since cfs_rq's can end up not
being decayed properly. For two sibling control groups with the same
priority, this can often lead to a load ratio of 99/1 (!!).

This happens because when a cfs_rq is throttled, all the descendant
cfs_rq's will be removed from the leaf list. When they initial cfs_rq
is unthrottled, it will currently only re add descendant cfs_rq's if
they have one or more entities enqueued. This is not a perfect
heuristic.

Instead, we insert all cfs_rq's that contain one or more enqueued
entities, or it its load is not completely decayed.

Can often lead to situations like this for equally weighted control
groups:

  $ ps u -C stress
  USER         PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
  root       10009 88.8  0.0   3676   100 pts/1    R+   11:04   0:13 stress --cpu 1
  root       10023  3.0  0.0   3676   104 pts/1    R+   11:04   0:00 stress --cpu 1

Fixes: 31bc6aeaab ("sched/fair: Optimize update_blocked_averages()")
[vingo: !SMP build fix]
Signed-off-by: Odin Ugedal <odin@uged.al>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20210612112815.61678-1-odin@uged.al
2021-06-14 22:58:47 +02:00
Viresh Kumar
771fac5e26 Revert "cpufreq: CPPC: Add support for frequency invariance"
This reverts commit 4c38f2df71.

There are few races in the frequency invariance support for CPPC driver,
namely the driver doesn't stop the kthread_work and irq_work on policy
exit during suspend/resume or CPU hotplug.

A proper fix won't be possible for the 5.13-rc, as it requires a lot of
changes. Lets revert the patch instead for now.

Fixes: 4c38f2df71 ("cpufreq: CPPC: Add support for frequency invariance")
Reported-by: Qian Cai <quic_qiancai@quicinc.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-14 15:55:02 +02:00
Linus Torvalds
99f925947a Misc fixes:
- Fix performance regression caused by lack of intended
    batching of RCU callbacks by over-eager NOHZ-full code.
 
  - Fix cgroups related corruption of load_avg and load_sum metrics.
 
  - Three fixes to fix blocked load, util_sum/runnable_sum and
    util_est tracking bugs.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Misc fixes:

   - Fix performance regression caused by lack of intended batching of
     RCU callbacks by over-eager NOHZ-full code.

   - Fix cgroups related corruption of load_avg and load_sum metrics.

   - Three fixes to fix blocked load, util_sum/runnable_sum and util_est
     tracking bugs"

* tag 'sched-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/fair: Fix util_est UTIL_AVG_UNCHANGED handling
  sched/pelt: Ensure that *_sum is always synced with *_avg
  tick/nohz: Only check for RCU deferred wakeup on user/guest entry when needed
  sched/fair: Make sure to update tg contrib for blocked load
  sched/fair: Keep load_avg and load_sum synced
2021-06-12 11:41:28 -07:00
Linus Torvalds
191aaf6cc4 Misc fixes:
- Fix the NMI watchdog on ancient Intel CPUs
 
  - Remove a misguided, NMI-unsafe KASAN callback
    from the NMI-safe irq_work path used by perf.
 
  - Fix uncore events on Ice Lake servers.
 
  - Someone booted maxcpus=1 on an SNB-EP, and the
    uncore driver emitted warnings and was probably
    buggy. Fix it.
 
  - KCSAN found a genuine data race in the core perf
    code. Somewhat ironically the bug was introduced
    through a recent race fix. :-/ In our defense, the
    new race window was much more narrow. Fix it.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull perf fixes from Ingo Molnar:
 "Misc fixes:

   - Fix the NMI watchdog on ancient Intel CPUs

   - Remove a misguided, NMI-unsafe KASAN callback from the NMI-safe
     irq_work path used by perf.

   - Fix uncore events on Ice Lake servers.

   - Someone booted maxcpus=1 on an SNB-EP, and the uncore driver
     emitted warnings and was probably buggy. Fix it.

   - KCSAN found a genuine data race in the core perf code. Somewhat
     ironically the bug was introduced through a recent race fix. :-/
     In our defense, the new race window was much more narrow. Fix it"

* tag 'perf-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/nmi_watchdog: Fix old-style NMI watchdog regression on old Intel CPUs
  irq_work: Make irq_work_queue() NMI-safe again
  perf/x86/intel/uncore: Fix M2M event umask for Ice Lake server
  perf/x86/intel/uncore: Fix a kernel WARNING triggered by maxcpus=1
  perf: Fix data race between pin_count increment/decrement
2021-06-12 11:34:49 -07:00
Linus Torvalds
ad347abe4a Tracing fixes for 5.13:
- Fix the length check in the temp buffer filter
 
  - Fix build failure in bootconfig tools for "fallthrough" macro
 
  - Fix error return of bootconfig apply_xbc() routine
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Merge tag 'trace-v5.13-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix the length check in the temp buffer filter

 - Fix build failure in bootconfig tools for "fallthrough" macro

 - Fix error return of bootconfig apply_xbc() routine

* tag 'trace-v5.13-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Correct the length check which causes memory corruption
  ftrace: Do not blindly read the ip address in ftrace_bug()
  tools/bootconfig: Fix a build error accroding to undefined fallthrough
  tools/bootconfig: Fix error return code in apply_xbc()
2021-06-11 17:05:03 -07:00
Linus Torvalds
f09eacca59 Merge branch 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup fix from Tejun Heo:
 "This is a high priority but low risk fix for a cgroup1 bug where
  rename(2) can change a cgroup's name to something which can break
  parsing of /proc/PID/cgroup"

* 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
  cgroup1: don't allow '\n' in renaming
2021-06-10 12:01:22 -07:00
Alexander Kuznetsov
b7e24eb1ca cgroup1: don't allow '\n' in renaming
cgroup_mkdir() have restriction on newline usage in names:
$ mkdir $'/sys/fs/cgroup/cpu/test\ntest2'
mkdir: cannot create directory
'/sys/fs/cgroup/cpu/test\ntest2': Invalid argument

But in cgroup1_rename() such check is missed.
This allows us to make /proc/<pid>/cgroup unparsable:
$ mkdir /sys/fs/cgroup/cpu/test
$ mv /sys/fs/cgroup/cpu/test $'/sys/fs/cgroup/cpu/test\ntest2'
$ echo $$ > $'/sys/fs/cgroup/cpu/test\ntest2'
$ cat /proc/self/cgroup
11:pids:/
10:freezer:/
9:hugetlb:/
8:cpuset:/
7:blkio:/user.slice
6:memory:/user.slice
5:net_cls,net_prio:/
4:perf_event:/
3:devices:/user.slice
2:cpu,cpuacct:/test
test2
1:name=systemd:/
0::/

Signed-off-by: Alexander Kuznetsov <wwfq@yandex-team.ru>
Reported-by: Andrey Krasichkov <buglloc@yandex-team.ru>
Acked-by: Dmitry Yakunin <zeil@yandex-team.ru>
Cc: stable@vger.kernel.org
Signed-off-by: Tejun Heo <tj@kernel.org>
2021-06-10 09:58:50 -04:00
Peter Zijlstra
156172a13f irq_work: Make irq_work_queue() NMI-safe again
Someone carelessly put NMI unsafe code in irq_work_queue(), breaking
just about every single user. Also, someone has a terrible comment
style.

Fixes: e2b5bcf9f5 ("irq_work: record irq_work_queue() call stack")
Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/YL+uBq8LzXXZsYVf@hirez.programming.kicks-ass.net
2021-06-10 10:00:08 +02:00
Liangyan
3e08a9f976 tracing: Correct the length check which causes memory corruption
We've suffered from severe kernel crashes due to memory corruption on
our production environment, like,

Call Trace:
[1640542.554277] general protection fault: 0000 [#1] SMP PTI
[1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G
[1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190
[1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286
[1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX:
0000000006e931bf
[1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI:
ffff9a45ff004300
[1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09:
0000000000000000
[1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12:
ffffffff9a20608d
[1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15:
696c662f65636976
[1640542.563128] FS:  00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000)
knlGS:0000000000000000
[1640542.563937] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4:
00000000003606e0
[1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2:
0000000000000000
[1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:
0000000000000400
[1640542.566742] Call Trace:
[1640542.567009]  anon_vma_clone+0x5d/0x170
[1640542.567417]  __split_vma+0x91/0x1a0
[1640542.567777]  do_munmap+0x2c6/0x320
[1640542.568128]  vm_munmap+0x54/0x70
[1640542.569990]  __x64_sys_munmap+0x22/0x30
[1640542.572005]  do_syscall_64+0x5b/0x1b0
[1640542.573724]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[1640542.575642] RIP: 0033:0x7f45d6e61e27

James Wang has reproduced it stably on the latest 4.19 LTS.
After some debugging, we finally proved that it's due to ftrace
buffer out-of-bound access using a debug tool as follows:
[   86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000
[   86.780806]  no_context+0xdf/0x3c0
[   86.784327]  __do_page_fault+0x252/0x470
[   86.788367]  do_page_fault+0x32/0x140
[   86.792145]  page_fault+0x1e/0x30
[   86.795576]  strncpy_from_unsafe+0x66/0xb0
[   86.799789]  fetch_memory_string+0x25/0x40
[   86.804002]  fetch_deref_string+0x51/0x60
[   86.808134]  kprobe_trace_func+0x32d/0x3a0
[   86.812347]  kprobe_dispatcher+0x45/0x50
[   86.816385]  kprobe_ftrace_handler+0x90/0xf0
[   86.820779]  ftrace_ops_assist_func+0xa1/0x140
[   86.825340]  0xffffffffc00750bf
[   86.828603]  do_sys_open+0x5/0x1f0
[   86.832124]  do_syscall_64+0x5b/0x1b0
[   86.835900]  entry_SYSCALL_64_after_hwframe+0x44/0xa9

commit b220c049d5 ("tracing: Check length before giving out
the filter buffer") adds length check to protect trace data
overflow introduced in 0fc1b09ff1, seems that this fix can't prevent
overflow entirely, the length check should also take the sizeof
entry->array[0] into account, since this array[0] is filled the
length of trace data and occupy addtional space and risk overflow.

Link: https://lkml.kernel.org/r/20210607125734.1770447-1-liangyan.peng@linux.alibaba.com

Cc: stable@vger.kernel.org
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Xunlei Pang <xlpang@linux.alibaba.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixes: b220c049d5 ("tracing: Check length before giving out the filter buffer")
Reviewed-by: Xunlei Pang <xlpang@linux.alibaba.com>
Reviewed-by: yinbinbin <yinbinbin@alibabacloud.com>
Reviewed-by: Wetp Zhang <wetp.zy@linux.alibaba.com>
Tested-by: James Wang <jnwang@linux.alibaba.com>
Signed-off-by: Liangyan <liangyan.peng@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-08 16:44:00 -04:00
Steven Rostedt (VMware)
6c14133d2d ftrace: Do not blindly read the ip address in ftrace_bug()
It was reported that a bug on arm64 caused a bad ip address to be used for
updating into a nop in ftrace_init(), but the error path (rightfully)
returned -EINVAL and not -EFAULT, as the bug caused more than one error to
occur. But because -EINVAL was returned, the ftrace_bug() tried to report
what was at the location of the ip address, and read it directly. This
caused the machine to panic, as the ip was not pointing to a valid memory
address.

Instead, read the ip address with copy_from_kernel_nofault() to safely
access the memory, and if it faults, report that the address faulted,
otherwise report what was in that location.

Link: https://lore.kernel.org/lkml/20210607032329.28671-1-mark-pk.tsai@mediatek.com/

Cc: stable@vger.kernel.org
Fixes: 05736a427f ("ftrace: warn on failure to disable mcount callers")
Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-08 16:44:00 -04:00
Linus Torvalds
9d32fa5d74 Networking fixes for 5.13-rc5, including fixes from bpf, wireless,
netfilter and wireguard trees.
 
 The bpf vs lockdown+audit fix is the most notable.
 
 Current release - regressions:
 
  - virtio-net: fix page faults and crashes when XDP is enabled
 
  - mlx5e: fix HW timestamping with CQE compression, and make sure they
           are only allowed to coexist with capable devices
 
  - stmmac:
         - fix kernel panic due to NULL pointer dereference of mdio_bus_data
         - fix double clk unprepare when no PHY device is connected
 
 Current release - new code bugs:
 
  - mt76: a few fixes for the recent MT7921 devices and runtime
          power management
 
 Previous releases - regressions:
 
  - ice: - track AF_XDP ZC enabled queues in bitmap to fix copy mode Tx
         - fix allowing VF to request more/less queues via virtchnl
 	- correct supported and advertised autoneg by using PHY capabilities
         - allow all LLDP packets from PF to Tx
 
  - kbuild: quote OBJCOPY var to avoid a pahole call break the build
 
 Previous releases - always broken:
 
  - bpf, lockdown, audit: fix buggy SELinux lockdown permission checks
 
  - mt76: address the recent FragAttack vulnerabilities not covered
          by generic fixes
 
  - ipv6: fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions
 
  - Bluetooth:
  	 - fix the erroneous flush_work() order, to avoid double free
          - use correct lock to prevent UAF of hdev object
 
  - nfc: fix NULL ptr dereference in llcp_sock_getname() after failed connect
 
  - ieee802154: multiple fixes to error checking and return values
 
  - igb: fix XDP with PTP enabled
 
  - intel: add correct exception tracing for XDP
 
  - tls: fix use-after-free when TLS offload device goes down and back up
 
  - ipvs: ignore IP_VS_SVC_F_HASHED flag when adding service
 
  - netfilter: nft_ct: skip expectations for confirmed conntrack
 
  - mptcp: fix falling back to TCP in presence of out of order packets
           early in connection lifetime
 
  - wireguard: switch from O(n) to a O(1) algorithm for maintaining peers,
           fixing stalls and a large memory leak in the process
 
 Misc:
 
  - devlink: correct VIRTUAL port to not have phys_port attributes
 
  - Bluetooth: fix VIRTIO_ID_BT assigned number
 
  - net: return the correct errno code ENOBUF -> ENOMEM
 
  - wireguard:
          - peer: allocate in kmem_cache saving 25% on peer memory
          - do not use -O3
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-5.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Jakub Kicinski:
 "Networking fixes, including fixes from bpf, wireless, netfilter and
  wireguard trees.

  The bpf vs lockdown+audit fix is the most notable.

  Things haven't slowed down just yet, both in terms of regressions in
  current release and largish fixes for older code, but we usually see a
  slowdown only after -rc5.

  Current release - regressions:

   - virtio-net: fix page faults and crashes when XDP is enabled

   - mlx5e: fix HW timestamping with CQE compression, and make sure they
     are only allowed to coexist with capable devices

   - stmmac:
      - fix kernel panic due to NULL pointer dereference of
        mdio_bus_data
      - fix double clk unprepare when no PHY device is connected

  Current release - new code bugs:

   - mt76: a few fixes for the recent MT7921 devices and runtime power
     management

  Previous releases - regressions:

   - ice:
      - track AF_XDP ZC enabled queues in bitmap to fix copy mode Tx
      - fix allowing VF to request more/less queues via virtchnl
      - correct supported and advertised autoneg by using PHY
        capabilities
      - allow all LLDP packets from PF to Tx

   - kbuild: quote OBJCOPY var to avoid a pahole call break the build

  Previous releases - always broken:

   - bpf, lockdown, audit: fix buggy SELinux lockdown permission checks

   - mt76: address the recent FragAttack vulnerabilities not covered by
     generic fixes

   - ipv6: fix KASAN: slab-out-of-bounds Read in
     fib6_nh_flush_exceptions

   - Bluetooth:
      - fix the erroneous flush_work() order, to avoid double free
      - use correct lock to prevent UAF of hdev object

   - nfc: fix NULL ptr dereference in llcp_sock_getname() after failed
     connect

   - ieee802154: multiple fixes to error checking and return values

   - igb: fix XDP with PTP enabled

   - intel: add correct exception tracing for XDP

   - tls: fix use-after-free when TLS offload device goes down and back
     up

   - ipvs: ignore IP_VS_SVC_F_HASHED flag when adding service

   - netfilter: nft_ct: skip expectations for confirmed conntrack

   - mptcp: fix falling back to TCP in presence of out of order packets
     early in connection lifetime

   - wireguard: switch from O(n) to a O(1) algorithm for maintaining
     peers, fixing stalls and a large memory leak in the process

  Misc:

   - devlink: correct VIRTUAL port to not have phys_port attributes

   - Bluetooth: fix VIRTIO_ID_BT assigned number

   - net: return the correct errno code ENOBUF -> ENOMEM

   - wireguard:
      - peer: allocate in kmem_cache saving 25% on peer memory
      - do not use -O3"

* tag 'net-5.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits)
  cxgb4: avoid link re-train during TC-MQPRIO configuration
  sch_htb: fix refcount leak in htb_parent_to_leaf_offload
  wireguard: allowedips: free empty intermediate nodes when removing single node
  wireguard: allowedips: allocate nodes in kmem_cache
  wireguard: allowedips: remove nodes in O(1)
  wireguard: allowedips: initialize list head in selftest
  wireguard: peer: allocate in kmem_cache
  wireguard: use synchronize_net rather than synchronize_rcu
  wireguard: do not use -O3
  wireguard: selftests: make sure rp_filter is disabled on vethc
  wireguard: selftests: remove old conntrack kconfig value
  virtchnl: Add missing padding to virtchnl_proto_hdrs
  ice: Allow all LLDP packets from PF to Tx
  ice: report supported and advertised autoneg using PHY capabilities
  ice: handle the VF VSI rebuild failure
  ice: Fix VFR issues for AVF drivers that expect ATQLEN cleared
  ice: Fix allowing VF to request more/less queues via virtchnl
  virtio-net: fix for skb_over_panic inside big mode
  ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions
  fib: Return the correct errno code
  ...
2021-06-04 18:25:39 -07:00
Dietmar Eggemann
68d7a19068 sched/fair: Fix util_est UTIL_AVG_UNCHANGED handling
The util_est internal UTIL_AVG_UNCHANGED flag which is used to prevent
unnecessary util_est updates uses the LSB of util_est.enqueued. It is
exposed via _task_util_est() (and task_util_est()).

Commit 92a801e5d5 ("sched/fair: Mask UTIL_AVG_UNCHANGED usages")
mentions that the LSB is lost for util_est resolution but
find_energy_efficient_cpu() checks if task_util_est() returns 0 to
return prev_cpu early.

_task_util_est() returns the max value of util_est.ewma and
util_est.enqueued or'ed w/ UTIL_AVG_UNCHANGED.
So task_util_est() returning the max of task_util() and
_task_util_est() will never return 0 under the default
SCHED_FEAT(UTIL_EST, true).

To fix this use the MSB of util_est.enqueued instead and keep the flag
util_est internal, i.e. don't export it via _task_util_est().

The maximal possible util_avg value for a task is 1024 so the MSB of
'unsigned int util_est.enqueued' isn't used to store a util value.

As a caveat the code behind the util_est_se trace point has to filter
UTIL_AVG_UNCHANGED to see the real util_est.enqueued value which should
be easy to do.

This also fixes an issue report by Xuewen Yan that util_est_update()
only used UTIL_AVG_UNCHANGED for the subtrahend of the equation:

  last_enqueued_diff = ue.enqueued - (task_util() | UTIL_AVG_UNCHANGED)

Fixes: b89997aa88 sched/pelt: Fix task util_est update filtering
Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Xuewen Yan <xuewen.yan@unisoc.com>
Reviewed-by: Vincent Donnefort <vincent.donnefort@arm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lore.kernel.org/r/20210602145808.1562603-1-dietmar.eggemann@arm.com
2021-06-03 15:47:23 +02:00