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  1. 16 Jul, 2019 12 commits
  3. 18 Jun, 2019 1 commit
    • Gustavo A. R. Silva's avatar
      tracepoint: Use struct_size() in kmalloc() · f0553dcb
      Gustavo A. R. Silva authored 
      One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct tp_probes {
	...
        struct tracepoint_func probes[0];
};

instance = kmalloc(sizeof(sizeof(struct tp_probes) +
			sizeof(struct tracepoint_func) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, probes, count) GFP_KERNEL);

This code was detected with the help of Coccinelle.
Signed-off-by: default avatarGustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      f0553dcb
  5. 28 May, 2019 1 commit
    • Steven Rostedt (VMware)'s avatar
      ring-buffer: Remove HAVE_64BIT_ALIGNED_ACCESS · 86b3de60
      Steven Rostedt (VMware) authored 
      Commit c19fa94a ("Add HAVE_64BIT_ALIGNED_ACCESS") added the config for
architectures that required 64bit aligned access for all 64bit words. As
the ftrace ring buffer stores data on 4 byte alignment, this config option
was used to force it to store data on 8 byte alignment to make sure the data
being stored and written directly into the ring buffer was 8 byte aligned as
it would cause issues trying to write an 8 byte word on a 4 not 8 byte
aligned memory location.

But with the removal of the metag architecture, which was the only
architecture to use this, there is no architecture supported by Linux that
requires 8 byte aligne access for all 8 byte words (4 byte alignment is good
enough). Removing this config can simplify the code a bit.
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      86b3de60
  7. 26 May, 2019 17 commits
  9. 22 May, 2019 1 commit
  11. 21 May, 2019 3 commits
    • Tom Zanussi's avatar
      tracing: Add a check_val() check before updating cond_snapshot() track_val · 9b2ca371
      Tom Zanussi authored 
      Without this check a snapshot is taken whenever a bucket's max is hit,
rather than only when the global max is hit, as it should be.

Before:

  In this example, we do a first run of the workload (cyclictest),
  examine the output, note the max ('triggering value') (347), then do
  a second run and note the max again.

  In this case, the max in the second run (39) is below the max in the
  first run, but since we haven't cleared the histogram, the first max
  is still in the histogram and is higher than any other max, so it
  should still be the max for the snapshot.  It isn't however - the
  value should still be 347 after the second run.

  # echo 'hist:keys=pid:ts0=common_timestamp.usecs if comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_waking/trigger
  # echo 'hist:keys=next_pid:wakeup_lat=common_timestamp.usecs-$ts0:onmax($wakeup_lat).save(next_prio,next_comm,prev_pid,prev_prio,prev_comm):onmax($wakeup_lat).snapshot() if next_comm=="cyclictest"' >> /sys/kernel/debug/tracing/events/sched/sched_switch/trigger

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2143 } hitcount:        199
    max:         44  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2145 } hitcount:       1325
    max:         38  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2144 } hitcount:       1982
    max:        347  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  Snapshot taken (see tracing/snapshot).  Details:
      triggering value { onmax($wakeup_lat) }:        347
      triggered by event with key: { next_pid:       2144 }

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2143 } hitcount:        199
    max:         44  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2148 } hitcount:        199
    max:         16  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/1

  { next_pid:       2145 } hitcount:       1325
    max:         38  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2150 } hitcount:       1326
    max:         39  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2144 } hitcount:       1982
    max:        347  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  { next_pid:       2149 } hitcount:       1983
    max:        130  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/0

  Snapshot taken (see tracing/snapshot).  Details:
    triggering value { onmax($wakeup_lat) }:    39
    triggered by event with key: { next_pid:       2150 }

After:

  In this example, we do a first run of the workload (cyclictest),
  examine the output, note the max ('triggering value') (375), then do
  a second run and note the max again.

  In this case, the max in the second run is still 375, the highest in
  any bucket, as it should be.

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2072 } hitcount:        200
    max:         28  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/5

  { next_pid:       2074 } hitcount:       1323
    max:        375  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2073 } hitcount:       1980
    max:        153  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  Snapshot taken (see tracing/snapshot).  Details:
    triggering value { onmax($wakeup_lat) }:        375
    triggered by event with key: { next_pid:       2074 }

  # cyclictest -p 80 -n -s -t 2 -D 2

  # cat /sys/kernel/debug/tracing/events/sched/sched_switch/hist

  { next_pid:       2101 } hitcount:        199
    max:         49  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  { next_pid:       2072 } hitcount:        200
    max:         28  next_prio:        120  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/5

  { next_pid:       2074 } hitcount:       1323
    max:        375  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/2

  { next_pid:       2103 } hitcount:       1325
    max:         74  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/4

  { next_pid:       2073 } hitcount:       1980
    max:        153  next_prio:         19  next_comm: cyclictest
    prev_pid:          0  prev_prio:        120  prev_comm: swapper/6

  { next_pid:       2102 } hitcount:       1981
    max:         84  next_prio:         19  next_comm: cyclictest
    prev_pid:         12  prev_prio:        120  prev_comm: kworker/0:1

  Snapshot taken (see tracing/snapshot).  Details:
    triggering value { onmax($wakeup_lat) }:        375
    triggered by event with key: { next_pid:       2074 }

Link: http://lkml.kernel.org/r/95958351329f129c07504b4d1769c47a97b70d65.1555597045.git.tom.zanussi@linux.intel.com

Cc: stable@vger.kernel.org
Fixes: a3785b7e ("tracing: Add hist trigger snapshot() action")
Signed-off-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      9b2ca371
    • Tom Zanussi's avatar
      tracing: Check keys for variable references in expressions too · c8d94a18
      Tom Zanussi authored 
      There's an existing check for variable references in keys, but it
doesn't go far enough.  It checks whether a key field is a variable
reference but doesn't check whether it's an expression containing
variable references, which can cause the same problems for callers.

Use the existing field_has_hist_vars() function rather than a direct
top-level flag check to catch all possible variable references.

Link: http://lkml.kernel.org/r/e8c3d3d53db5ca90ceea5a46e5413103a6902fc7.1555597045.git.tom.zanussi@linux.intel.com

Cc: stable@vger.kernel.org
Fixes: 067fe038 ("tracing: Add variable reference handling to hist triggers")
Reported-by: default avatarVincent Bernat <vincent@bernat.ch>
Signed-off-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      c8d94a18
    • Tom Zanussi's avatar
      tracing: Prevent hist_field_var_ref() from accessing NULL tracing_map_elts · 55267c88
      Tom Zanussi authored 
      hist_field_var_ref() is an implementation of hist_field_fn_t(), which
can be called with a null tracing_map_elt elt param when assembling a
key in event_hist_trigger().

In the case of hist_field_var_ref() this doesn't make sense, because a
variable can only be resolved by looking it up using an already
assembled key i.e. a variable can't be used to assemble a key since
the key is required in order to access the variable.

Upper layers should prevent the user from constructing a key using a
variable in the first place, but in case one slips through, it
shouldn't cause a NULL pointer dereference.  Also if one does slip
through, we want to know about it, so emit a one-time warning in that
case.

Link: http://lkml.kernel.org/r/64ec8dc15c14d305295b64cdfcc6b2b9dd14753f.1555597045.git.tom.zanussi@linux.intel.comReported-by: default avatarVincent Bernat <vincent@bernat.ch>
Signed-off-by: default avatarTom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: default avatarSteven Rostedt (VMware) <rostedt@goodmis.org>
      55267c88
  13. 19 May, 2019 5 commits
    • Linus Torvalds's avatar
      Linux 5.2-rc1 · a188339c
      Linus Torvalds authored
      a188339c
    • Linus Torvalds's avatar
      Merge tag 'upstream-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs · 2e2c1220
      Linus Torvalds authored 
      Pull UBIFS fixes from Richard Weinberger:

 - build errors wrt xattrs

 - mismerge which lead to a wrong Kconfig ifdef

 - missing endianness conversion

* tag 'upstream-5.2-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/ubifs:
  ubifs: Convert xattr inum to host order
  ubifs: Use correct config name for encryption
  ubifs: Fix build error without CONFIG_UBIFS_FS_XATTR
      2e2c1220
    • Linus Torvalds's avatar
      Merge branch 'akpm' (patches from Andrew) · cb6f8739
      Linus Torvalds authored 
      Merge yet more updates from Andrew Morton:
 "A few final bits:

   - large changes to vmalloc, yielding large performance benefits

   - tweak the console-flush-on-panic code

   - a few fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  panic: add an option to replay all the printk message in buffer
  initramfs: don't free a non-existent initrd
  fs/writeback.c: use rcu_barrier() to wait for inflight wb switches going into workqueue when umount
  mm/compaction.c: correct zone boundary handling when isolating pages from a pageblock
  mm/vmap: add DEBUG_AUGMENT_LOWEST_MATCH_CHECK macro
  mm/vmap: add DEBUG_AUGMENT_PROPAGATE_CHECK macro
  mm/vmalloc.c: keep track of free blocks for vmap allocation
      cb6f8739
    • Linus Torvalds's avatar
      Merge tag 'kbuild-v5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild · ff8583d6
      Linus Torvalds authored 
      Pull more Kbuild updates from Masahiro Yamada:

 - remove unneeded use of cc-option, cc-disable-warning, cc-ldoption

 - exclude tracked files from .gitignore

 - re-enable -Wint-in-bool-context warning

 - refactor samples/Makefile

 - stop building immediately if syncconfig fails

 - do not sprinkle error messages when $(CC) does not exist

 - move arch/alpha/defconfig to the configs subdirectory

 - remove crappy header search path manipulation

 - add comment lines to .config to clarify the end of menu blocks

 - check uniqueness of module names (adding new warnings intentionally)

* tag 'kbuild-v5.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (24 commits)
  kconfig: use 'else ifneq' for Makefile to improve readability
  kbuild: check uniqueness of module names
  kconfig: Terminate menu blocks with a comment in the generated config
  kbuild: add LICENSES to KBUILD_ALLDIRS
  kbuild: remove 'addtree' and 'flags' magic for header search paths
  treewide: prefix header search paths with $(srctree)/
  media: prefix header search paths with $(srctree)/
  media: remove unneeded header search paths
  alpha: move arch/alpha/defconfig to arch/alpha/configs/defconfig
  kbuild: terminate Kconfig when $(CC) or $(LD) is missing
  kbuild: turn auto.conf.cmd into a mandatory include file
  .gitignore: exclude .get_maintainer.ignore and .gitattributes
  kbuild: add all Clang-specific flags unconditionally
  kbuild: Don't try to add '-fcatch-undefined-behavior' flag
  kbuild: add some extra warning flags unconditionally
  kbuild: add -Wvla flag unconditionally
  arch: remove dangling asm-generic wrappers
  samples: guard sub-directories with CONFIG options
  kbuild: re-enable int-in-bool-context warning
  MAINTAINERS: kbuild: Add pattern for scripts/*vmlinux*
  ...
      ff8583d6
    • Linus Torvalds's avatar
      Merge branch 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux · f23d8719
      Linus Torvalds authored 
      Pull i2c updates from Wolfram Sang:
 "Some I2C core API additions which are kind of simple but enhance error
  checking for users a lot, especially by returning errno now.

  There are wrappers to still support the old API but it will be removed
  once all users are converted"

* 'i2c/for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: core: add device-managed version of i2c_new_dummy
  i2c: core: improve return value handling of i2c_new_device and i2c_new_dummy
      f23d8719
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