linux-stable.git/tools/perf/tests, branch v5.4.26

perf tests: Disable bp_signal testing for arm64

2019-12-31T15:44:12+00:00

[ Upstream commit 6a5f3d94cb69a185b921cb92c39888dc31009acb ]

As there are several discussions for enabling perf breakpoint signal
testing on arm64 platform: arm64 needs to rely on single-step to execute
the breakpointed instruction and then reinstall the breakpoint exception
handler.  But if we hook the breakpoint with a signal, the signal
handler will do the stepping rather than the breakpointed instruction,
this causes infinite loops as below:

         Kernel space              |            Userspace
  ---------------------------------|--------------------------------
                                   |  __test_function() -> hit
				   |                       breakpoint
  breakpoint_handler()             |
    `-> user_enable_single_step()  |
  do_signal()                      |
                                   |  sig_handler() -> Step one
				   |                instruction and
				   |                trap to kernel
  single_step_handler()            |
    `-> reinstall_suspended_bps()  |
                                   |  __test_function() -> hit
				   |     breakpoint again and
				   |     repeat up flow infinitely

As Will Deacon mentioned [1]: "that we require the overflow handler to
do the stepping on arm/arm64, which is relied upon by GDB/ptrace. The
hw_breakpoint code is a complete disaster so my preference would be to
rip out the perf part and just implement something directly in ptrace,
but it's a pretty horrible job".  Though Will commented this on arm
architecture, but the comment also can apply on arm64 architecture.

For complete information, I searched online and found a few years back,
Wang Nan sent one patch 'arm64: Store breakpoint single step state into
pstate' [2]; the patch tried to resolve this issue by avoiding single
stepping in signal handler and defer to enable the signal stepping when
return to __test_function().  The fixing was not merged due to the
concern for missing to handle different usage cases.

Based on the info, the most feasible way is to skip Perf breakpoint
signal testing for arm64 and this could avoid the duplicate
investigation efforts when people see the failure.  This patch skips
this case on arm64 platform, which is same with arm architecture.

[1] https://lkml.org/lkml/2018/11/15/205
[2] https://lkml.org/lkml/2015/12/23/477

Signed-off-by: Leo Yan 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Brajeswar Ghosh 
Cc: Florian Fainelli 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Souptick Joarder 
Cc: Will Deacon 
Link: http://lore.kernel.org/lkml/20191018085531.6348-3-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf test: Avoid infinite loop for task exit case

2019-12-31T15:44:06+00:00

[ Upstream commit 791ce9c48c79210d2ffcdbe69421e7783b32921f ]

When executing the task exit testing case, perf gets stuck in an endless
loop this case and doesn't return back on Arm64 Juno board.

After digging into this issue, since Juno board has Arm's big.LITTLE
CPUs, thus the PMUs are not compatible between the big CPUs and little
CPUs.  This leads to a PMU event that cannot be enabled properly when
the traced task is migrated from one variant's CPU to another variant.
Finally, the test case runs into infinite loop for cannot read out any
event data after return from polling.

Eventually, we need to work out formal solution to allow PMU events can
be freely migrated from one CPU variant to another, but this is a
difficult task and a different topic.  This patch tries to fix the Perf
test case to avoid infinite loop, when the testing detects 1000 times
retrying for reading empty events, it will directly bail out and return
failure.  This allows the Perf tool can continue its other test cases.

Signed-off-by: Leo Yan 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Link: http://lore.kernel.org/lkml/20191011091942.29841-2-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf test: Report failure for mmap events

2019-12-31T15:44:06+00:00

[ Upstream commit 6add129c5d9210ada25217abc130df0b7096ee02 ]

When fail to mmap events in task exit case, it misses to set 'err' to
-1; thus the testing will not report failure for it.

This patch sets 'err' to -1 when fails to mmap events, thus Perf tool
can report correct result.

Fixes: d723a55096b8 ("perf test: Add test case for checking number of EXIT events")
Signed-off-by: Leo Yan 
Cc: Alexander Shishkin 
Cc: Jiri Olsa 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Link: http://lore.kernel.org/lkml/20191011091942.29841-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Sasha Levin

perf tests: Fix out of bounds memory access

2019-12-17T18:56:23+00:00

commit af8490eb2b33684e26a0a927a9d93ae43cd08890 upstream.

The test case 'Read backward ring buffer' failed on 32-bit architectures
which were found by LKFT perf testing.  The test failed on arm32 x15
device, qemu_arm32, qemu_i386, and found intermittent failure on i386;
the failure log is as below:

  50: Read backward ring buffer                  :
  --- start ---
  test child forked, pid 510
  Using CPUID GenuineIntel-6-9E-9
  mmap size 1052672B
  mmap size 8192B
  Finished reading overwrite ring buffer: rewind
  free(): invalid next size (fast)
  test child interrupted
  ---- end ----
  Read backward ring buffer: FAILED!

The log hints there have issue for memory usage, thus free() reports
error 'invalid next size' and directly exit for the case.  Finally, this
issue is root caused as out of bounds memory access for the data array
'evsel->id'.

The backward ring buffer test invokes do_test() twice.  'evsel->id' is
allocated at the first call with the flow:

  test__backward_ring_buffer()
    `-> do_test()
	  `-> evlist__mmap()
	        `-> evlist__mmap_ex()
	              `-> perf_evsel__alloc_id()

So 'evsel->id' is allocated with one item, and it will be used in
function perf_evlist__id_add():

   evsel->id[0] = id
   evsel->ids   = 1

At the second call for do_test(), it skips to initialize 'evsel->id'
and reuses the array which is allocated in the first call.  But
'evsel->ids' contains the stale value.  Thus:

   evsel->id[1] = id    -> out of bound access
   evsel->ids   = 2

To fix this issue, we will use evlist__open() and evlist__close() pair
functions to prepare and cleanup context for evlist; so 'evsel->id' and
'evsel->ids' can be initialized properly when invoke do_test() and avoid
the out of bounds memory access.

Fixes: ee74701ed8ad ("perf tests: Add test to check backward ring buffer")
Signed-off-by: Leo Yan 
Reviewed-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Naresh Kamboju 
Cc: Peter Zijlstra 
Cc: Wang Nan 
Cc: stable@vger.kernel.org # v4.10+
Link: http://lore.kernel.org/lkml/20191107020244.2427-1-leo.yan@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

perf tests: Avoid raising SEGV using an obvious NULL dereference

2019-09-27T12:26:14+00:00

An optimized build such as:

  make -C tools/perf CLANG=1 CC=clang EXTRA_CFLAGS="-O3

will turn the dereference operation into a ud2 instruction, raising a
SIGILL rather than a SIGSEGV. Use raise(..) for correctness and clarity.

Similar issues were addressed in Numfor Mbiziwo-Tiapo's patch:

  https://lkml.org/lkml/2019/7/8/1234

Committer testing:

Before:

  [root@quaco ~]# perf test hooks
  55: perf hooks                                            : Ok
  [root@quaco ~]# perf test -v hooks
  55: perf hooks                                            :
  --- start ---
  test child forked, pid 17092
  SIGSEGV is observed as expected, try to recover.
  Fatal error (SEGFAULT) in perf hook 'test'
  test child finished with 0
  ---- end ----
  perf hooks: Ok
  [root@quaco ~]#

After:

  [root@quaco ~]# perf test hooks
  55: perf hooks                                            : Ok
  [root@quaco ~]# perf test -v hooks
  55: perf hooks                                            :
  --- start ---
  test child forked, pid 17909
  SIGSEGV is observed as expected, try to recover.
  Fatal error (SEGFAULT) in perf hook 'test'
  test child finished with 0
  ---- end ----
  perf hooks: Ok
  [root@quaco ~]#

Fixes: a074865e60ed ("perf tools: Introduce perf hooks")
Signed-off-by: Ian Rogers 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Wang Nan 
Link: http://lore.kernel.org/lkml/20190925195924.152834-2-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Add perf_evlist__poll() function

2019-09-25T12:51:49+00:00

Move perf_evlist__poll() from tools/perf to libperf, it will be used in
the following patches.

And rename the existing perf's function to evlist__poll().

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20190913132355.21634-39-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: No need to include internal/lib.h from util/util.h

2019-09-25T12:51:48+00:00

That was done just to have users of writen() and readn(), that before
had their prototypes in util/util.h to get it without having to add an
include for internal/lib.h, but the right way is to add it and by now
all places already do it.

Fix a fallout were readlink() was used but unistd.h was being obtained
by luck thru util.h -> internal/lib.h, now to check why unistd.h is
being included there...

Cc: Adrian Hunter 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Link: https://lkml.kernel.org/n/tip-lcnytgrtafey3kwlfog2rzzj@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Move 'page_size' global variable to libperf

2019-09-25T12:51:48+00:00

We need the 'page_size' variable in libperf, so move it there.

Add a libperf_init() as a global libperf init function to obtain this
value via sysconf() at tool start.

Committer notes:

Add internal/lib.h to tools/perf/ files using 'page_size', sometimes
replacing util.h with it if that was the only reason for having util.h
included.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20190913132355.21634-33-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Add perf_evlist__id_add() function

2019-09-25T12:51:48+00:00

Add the perf_evlist__id_add() function to libperf as an internal
function.  We already have the 'heads' member in 'struct perf_evlist'.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20190913132355.21634-31-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

libperf: Add perf_evlist__first()/last() functions

2019-09-25T12:51:48+00:00

Add perf_evlist__first()/last() functions to libperf, as internal
functions and rename perf's origins to evlist__first/last.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: Michael Petlan 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lore.kernel.org/lkml/20190913132355.21634-29-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo