linux.git/kernel, branch v4.18-rc5

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

2018-07-13T20:36:36+00:00

Pull timer fixes from Ingo Molnar:
 "A clocksource driver fix and a revert"

* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  clocksource: arm_arch_timer: Set arch_mem_timer cpumask to cpu_possible_mask
  Revert "tick: Prefer a lower rating device only if it's CPU local device"

Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2018-07-13T19:50:42+00:00

Pull rseq fixes from Ingo Molnar:
 "Various rseq ABI fixes and cleanups: use get_user()/put_user(),
  validate parameters and use proper uapi types, etc"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  rseq/selftests: cleanup: Update comment above rseq_prepare_unload
  rseq: Remove unused types_32_64.h uapi header
  rseq: uapi: Declare rseq_cs field as union, update includes
  rseq: uapi: Update uapi comments
  rseq: Use get_user/put_user rather than __get_user/__put_user
  rseq: Use __u64 for rseq_cs fields, validate user inputs

Merge tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2018-07-13T18:40:11+00:00

Pull tracing fixlet from Steven Rostedt:
 "Joel Fernandes asked to add a feature in tracing that Android had its
  own patch internally for. I took it back in 4.13. Now he realizes that
  he had a mistake, and swapped the values from what Android had. This
  means that the old Android tools will break when using a new kernel
  that has the new feature on it.

  The options are:

   1. To swap it back to what Android wants.
   2. Add a command line option or something to do the swap
   3. Just let Android carry a patch that swaps it back

  Since it requires setting a tracing option to enable this anyway, I
  doubt there are other users of this than Android. Thus, I've decided
  to take option 1. If someone else is actually depending on the order
  that is in the kernel, then we will have to revert this change and go
  to option 2 or 3"

* tag 'trace-v4.18-rc3-3' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Reorder display of TGID to be after PID

tracing: Reorder display of TGID to be after PID

2018-07-12T23:56:25+00:00

Currently ftrace displays data in trace output like so:

                                       _-----=> irqs-off
                                      / _----=> need-resched
                                     | / _---=> hardirq/softirq
                                     || / _--=> preempt-depth
                                     ||| /     delay
            TASK-PID   CPU    TGID   ||||    TIMESTAMP  FUNCTION
               | |       |      |    ||||       |         |
            bash-1091  [000] ( 1091) d..2    28.313544: sched_switch:

However Android's trace visualization tools expect a slightly different
format due to an out-of-tree patch patch that was been carried for a
decade, notice that the TGID and CPU fields are reversed:

                                       _-----=> irqs-off
                                      / _----=> need-resched
                                     | / _---=> hardirq/softirq
                                     || / _--=> preempt-depth
                                     ||| /     delay
            TASK-PID    TGID   CPU   ||||    TIMESTAMP  FUNCTION
               | |        |      |   ||||       |         |
            bash-1091  ( 1091) [002] d..2    64.965177: sched_switch:

From kernel v4.13 onwards, during which TGID was introduced, tracing
with systrace on all Android kernels will break (most Android kernels
have been on 4.9 with Android patches, so this issues hasn't been seen
yet). From v4.13 onwards things will break.

The chrome browser's tracing tools also embed the systrace viewer which
uses the legacy TGID format and updates to that are known to be
difficult to make.

Considering this, I suggest we make this change to the upstream kernel
and backport it to all Android kernels. I believe this feature is merged
recently enough into the upstream kernel that it shouldn't be a problem.
Also logically, IMO it makes more sense to group the TGID with the
TASK-PID and the CPU after these.

Link: http://lkml.kernel.org/r/20180626000822.113931-1-joel@joelfernandes.org

Cc: jreck@google.com
Cc: tkjos@google.com
Cc: stable@vger.kernel.org
Fixes: 441dae8f2f29 ("tracing: Add support for display of tgid in trace output")
Signed-off-by: Joel Fernandes (Google) 
Signed-off-by: Steven Rostedt (VMware)

Merge tag 'trace-v4.18-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

2018-07-11T20:03:51+00:00

Pull kprobe fix from Steven Rostedt:
 "This fixes a memory leak in the kprobe code"

* tag 'trace-v4.18-rc3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing/kprobe: Release kprobe print_fmt properly

tracing/kprobe: Release kprobe print_fmt properly

2018-07-11T19:50:52+00:00

We don't release tk->tp.call.print_fmt when destroying
local uprobe. Also there's missing print_fmt kfree in
create_local_trace_kprobe error path.

Link: http://lkml.kernel.org/r/20180709141906.2390-1-jolsa@kernel.org

Cc: stable@vger.kernel.org
Fixes: e12f03d7031a ("perf/core: Implement the 'perf_kprobe' PMU")
Acked-by: Song Liu 
Acked-by: Masami Hiramatsu 
Signed-off-by: Jiri Olsa 
Signed-off-by: Steven Rostedt (VMware)

rseq: uapi: Declare rseq_cs field as union, update includes

2018-07-10T20:18:52+00:00

Declaring the rseq_cs field as a union between __u64 and two __u32
allows both 32-bit and 64-bit kernels to read the full __u64, and
therefore validate that a 32-bit user-space cleared the upper 32
bits, thus ensuring a consistent behavior between native 32-bit
kernels and 32-bit compat tasks on 64-bit kernels.

Check that the rseq_cs value read is < TASK_SIZE.

The asm/byteorder.h header needs to be included by rseq.h, now
that it is not using linux/types_32_64.h anymore.

Considering that only __32 and __u64 types are declared in linux/rseq.h,
the linux/types.h header should always be included for both kernel and
user-space code: including stdint.h is just for u64 and u32, which are
not used in this header at all.

Use copy_from_user()/clear_user() to interact with a 64-bit field,
because arm32 does not implement 64-bit __get_user, and ppc32 does not
64-bit get_user. Considering that the rseq_cs pointer does not need to
be loaded/stored with single-copy atomicity from the kernel anymore, we
can simply use copy_from_user()/clear_user().

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Thomas Gleixner 
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra 
Cc: "Paul E . McKenney" 
Cc: Boqun Feng 
Cc: Andy Lutomirski 
Cc: Dave Watson 
Cc: Paul Turner 
Cc: Andrew Morton 
Cc: Russell King 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: Chris Lameter 
Cc: Ben Maurer 
Cc: Steven Rostedt 
Cc: Josh Triplett 
Cc: Linus Torvalds 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Michael Kerrisk 
Cc: Joel Fernandes 
Cc: "Paul E. McKenney" 
Cc: "H. Peter Anvin" 
Link: https://lkml.kernel.org/r/20180709195155.7654-5-mathieu.desnoyers@efficios.com

rseq: uapi: Update uapi comments

2018-07-10T20:18:52+00:00

Update rseq uapi header comments to reflect that user-space need to do
thread-local loads/stores from/to the struct rseq fields.

As a consequence of this added requirement, the kernel does not need
to perform loads/stores with single-copy atomicity.

Update the comment associated to the "flags" fields to describe
more accurately that it's only useful to facilitate single-stepping
through rseq critical sections with debuggers.

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Thomas Gleixner 
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra 
Cc: "Paul E . McKenney" 
Cc: Boqun Feng 
Cc: Andy Lutomirski 
Cc: Dave Watson 
Cc: Paul Turner 
Cc: Andrew Morton 
Cc: Russell King 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: Chris Lameter 
Cc: Ben Maurer 
Cc: Steven Rostedt 
Cc: Josh Triplett 
Cc: Linus Torvalds 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Michael Kerrisk 
Cc: Joel Fernandes 
Cc: "Paul E. McKenney" 
Cc: "H. Peter Anvin" 
Link: https://lkml.kernel.org/r/20180709195155.7654-4-mathieu.desnoyers@efficios.com

rseq: Use get_user/put_user rather than __get_user/__put_user

2018-07-10T20:18:52+00:00

__get_user()/__put_user() is used to read values for address ranges that
were already checked with access_ok() on rseq registration.

It has been recognized that __get_user/__put_user are optimizing the
wrong thing. Replace them by get_user/put_user across rseq instead.

If those end up showing up in benchmarks, the proper approach would be to
use user_access_begin() / unsafe_{get,put}_user() / user_access_end()
anyway.

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Thomas Gleixner 
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra 
Cc: "Paul E . McKenney" 
Cc: Boqun Feng 
Cc: Andy Lutomirski 
Cc: Dave Watson 
Cc: Paul Turner 
Cc: Andrew Morton 
Cc: Russell King 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: Chris Lameter 
Cc: Ben Maurer 
Cc: Steven Rostedt 
Cc: Josh Triplett 
Cc: Linus Torvalds 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Michael Kerrisk 
Cc: Joel Fernandes 
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lkml.kernel.org/r/20180709195155.7654-3-mathieu.desnoyers@efficios.com

rseq: Use __u64 for rseq_cs fields, validate user inputs

2018-07-10T20:18:51+00:00

Change the rseq ABI so rseq_cs start_ip, post_commit_offset and abort_ip
fields are seen as 64-bit fields by both 32-bit and 64-bit kernels rather
that ignoring the 32 upper bits on 32-bit kernels. This ensures we have a
consistent behavior for a 32-bit binary executed on 32-bit kernels and in
compat mode on 64-bit kernels.

Validating the value of abort_ip field to be below TASK_SIZE ensures the
kernel don't return to an invalid address when returning to userspace
after an abort. I don't fully trust each architecture code to consistently
deal with invalid return addresses.

Validating the value of the start_ip and post_commit_offset fields
prevents overflow on arithmetic performed on those values, used to
check whether abort_ip is within the rseq critical section.

If validation fails, the process is killed with a segmentation fault.

When the signature encountered before abort_ip does not match the expected
signature, return -EINVAL rather than -EPERM to be consistent with other
input validation return codes from rseq_get_rseq_cs().

Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Thomas Gleixner 
Cc: linux-api@vger.kernel.org
Cc: Peter Zijlstra 
Cc: "Paul E . McKenney" 
Cc: Boqun Feng 
Cc: Andy Lutomirski 
Cc: Dave Watson 
Cc: Paul Turner 
Cc: Andrew Morton 
Cc: Russell King 
Cc: "H . Peter Anvin" 
Cc: Andi Kleen 
Cc: Chris Lameter 
Cc: Ben Maurer 
Cc: Steven Rostedt 
Cc: Josh Triplett 
Cc: Linus Torvalds 
Cc: Catalin Marinas 
Cc: Will Deacon 
Cc: Michael Kerrisk 
Cc: Joel Fernandes 
Cc: "Paul E. McKenney" 
Cc: "H. Peter Anvin" 
Link: https://lkml.kernel.org/r/20180709195155.7654-2-mathieu.desnoyers@efficios.com