The "probe libc's inet_pton & backtrace it with ping" test installs a
uprobe and uses perf record/script to check the backtrace. Currently
even if the "perf record" fails, the test reports success. Logs below:

  # ./perf test -v "probe libc's inet_pton & backtrace it with ping"
  81: probe libc's inet_pton & backtrace it with ping                 :
  --- start ---
  test child forked, pid 304211
  failed to open /tmp/perf.data.Btf: No such file or directory
  test child finished with 0
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: Ok

Fix this by adding check for presence of perf.data file
before proceeding with "perf script".

With the patch changes, test reports fail correctly.

 # ./perf test -v "probe libc's inet_pton & backtrace it with ping"
 81: probe libc's inet_pton & backtrace it with ping                 :
  --- start ---
  test child forked, pid 304358
  FAIL: perf record failed to create "/tmp/perf.data.Uoi"
  test child finished with -1
  ---- end ----
  probe libc's inet_pton & backtrace it with ping: FAILED!

Signed-off-by: Athira Rajeev <atrajeev@linux.vnet.ibm.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Disha Goel <disgoel@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lore.kernel.org/r/20230201180421.59640-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The test_pipe() function will check perf report and perf inject with
pipe input.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230131023350.1903992-5-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We should not call lseek(2) for pipes as it won't work.  And we already
in the proper place to read the data for AUXTRACE.  Add the comment like
in the PERF_RECORD_HEADER_TRACING_DATA.

Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230131023350.1903992-4-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

When it processes AUXTRACE_INFO, it calls to auxtrace_queue_data() to
collect AUXTRACE data first.  That won't work with pipe since it needs
lseek() to read the scattered aux data.

  $ perf record -o- -e intel_pt// true | perf report -i- --itrace=i100
  # To display the perf.data header info, please use --header/--header-only options.
  #
  0x4118 [0xa0]: failed to process type: 70
  Error:
  failed to process sample

For the pipe mode, it can handle the aux data as it gets.  But there's
no guarantee it can get the aux data in time.  So the following warning
will be shown at the beginning:

  WARNING: Intel PT with pipe mode is not recommended.
           The output cannot relied upon.  In particular,
           time stamps and the order of events may be incorrect.

Fixes: dbd13432

 ("perf intel-pt: Add support for decoding AUX area samples")
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230131023350.1903992-3-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

In copy_bytes(), it reads the data from the (input) fd and writes it to
the output file.  But it does with the read(2) unconditionally which
caused a problem of mixing buffered vs unbuffered I/O together.

You can see the problem when using pipes.

  $ perf record -e intel_pt// -o- true | perf inject -b > /dev/null
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.000 MB - ]
  0x45c0 [0x30]: failed to process type: 71

It should use perf_data__read() to honor the 'use_stdio' setting.

Fixes: 60136667

 ("perf data: Allow to use stdio functions for pipe mode")
Reviewed-by: Adrian Hunter <adrian.hunter@intel.com>
Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: https://lore.kernel.org/r/20230131023350.1903992-2-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

OpenCSD version 1.4 is released with support for FEAT_ITE.

This adds a new packet type, with associated output element ID in the
packet type enum - OCSD_GEN_TRC_ELEM_INSTRUMENTATION.

As we just ignore this packet in perf, add to the switch statement to
avoid the "enum not handled in switch error", but conditionally so as
not to break the perf build for older OpenCSD installations.

Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Mike Leach <mike.leach@linaro.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120153706.20388-1-mike.leach@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

'DWARF unwind' 'perf test' can sometimes fail:

  $ perf test -v 74
  Couldn't bump rlimit(MEMLOCK), failures may take place when creating BPF maps, etc
   74: Test dwarf unwind                                               :
  --- start ---
  test child forked, pid 3785254
  Problems creating module maps, continuing anyway...
  Problems creating module maps, continuing anyway...
  unwind: test__arch_unwind_sample:ip = 0x102d0ad4c (0x36ad4c)
  unwind: access_mem addr 0x7fffc33128c8, val 1031c3228, offset 120
  unwind: access_mem addr 0x7fffc33128d0, val 12427cc70, offset 128
  <snip>
  unwind: test_dwarf_unwind__krava_3:ip = 0x102b8768b (0x1e768b)
  unwind: access_mem addr 0x7fffc3313048, val 7fffc3313050, offset 2040
  unwind: access_mem addr 0x7fffc3313060, val 102b8777c, offset 2064
  unwind: test_dwarf_unwind__krava_2:ip = 0x102b8770b (0x1e770b)
  unwind: access_mem addr 0x7fffc3313088, val 7fffc3313090, offset 2104
  unwind: access_mem addr 0x7fffc33130a0, val 102b87890, offset 2128
  unwind: test_dwarf_unwind__krava_1:ip = 0x102b8777b (0x1e777b)
  unwind: access_mem addr 0x7fffc3313108, val 10323a274, offset 2232
  unwind: access_mem addr 0x7fffc3313110, val ffffffffffffffff, offset 2240
  unwind: access_mem addr 0x7fffc3313118, val 102c08ed0, offset 2248
  unwind: access_mem addr 0x7fffc3313120, val 1031db000, offset 2256
  unwind: access_mem addr 0x7fffc3313128, val 7fffc3313130, offset 2264
  unwind: access_mem addr 0x7fffc3313140, val 102b45ee8, offset 2288
  unwind: '':ip = 0x102b8788f (0x1e788f)
  failed: got unresolved address 0x102b8788f
  unwind: failed with 'no error'
  got wrong number of stack entries 0 != 8
  test child finished with -1
  ---- end ----
  Test dwarf unwind: FAILED!

We expect to resolve test__dwarf_unwind as the last symbol, but that
function can be optimized away:

  $ objdump -tT /usr/bin/perf | grep dwarf_unwind
  000000000083b018 g    DO .data	0000000000000040  Base        tests__dwarf_unwind
  00000000001e7750 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_1
  00000000001e76e0 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_2
  00000000001e7620 g    DF .text	00000000000000b4  Base        0x60 test_dwarf_unwind__krava_3
  00000000001e74f0 g    DF .text	0000000000000128  Base        0x60 test_dwarf_unwind__compare
  00000000001e7350 g    DF .text	000000000000019c  Base        0x60 test_dwarf_unwind__thread
  000000000083b000 g    DO .data	0000000000000018  Base        suite__dwarf_unwind

Fix this similar to commit fdf7c49c

 ("perf tests: Fix dwarf
unwind for stripped binaries") by marking the function as a global and
adding the 'noinline' attribute to it.

With this patch:

  $ objdump -tT perf | grep dwarf_unwind
  000000000083b018 g    DO .data	0000000000000040  Base        tests__dwarf_unwind
  00000000001e80f0 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_1
  00000000001e8080 g    DF .text	0000000000000068  Base        0x60 test_dwarf_unwind__krava_2
  00000000001e7fc0 g    DF .text	00000000000000b4  Base        0x60 test_dwarf_unwind__krava_3
  00000000001e7e90 g    DF .text	0000000000000128  Base        0x60 test_dwarf_unwind__compare
  00000000001e7cf0 g    DF .text	000000000000019c  Base        0x60 test_dwarf_unwind__thread
  00000000001e8160 g    DF .text	0000000000000248  Base        0x60 test__dwarf_unwind
  000000000083b000 g    DO .data	0000000000000018  Base        suite__dwarf_unwind
  $ ./perf test 74
   74: Test dwarf unwind                                               : Ok

Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Link: http://lore.kernel.org/lkml/20230125123442.107156-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

build_id__init() only copies the buildid data up to size leaving the
rest of the data array uninitialized. Copying the full array during
synthesis means the written event contains uninitialized memory.

Ensure the size is less that the buffer size and only copy the bytes
that were initialized. This was detected by the Clang/LLVM memory
sanitizer.

v2. Avoids the potential for copying too much as suggested by Arnaldo.

Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Tom Rix <trix@redhat.com>
Cc: llvm@lists.linux.dev
Link: https://lore.kernel.org/r/20230120185828.43231-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Setup is non-trivial so also link to the full SPE docs.

Signed-off-by: James Clark <james.clark@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-perf-users@vger.kernel.or
Link: https://lore.kernel.org/r/20230124145929.557891-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Make the sink error message more similar to the event error message that
reminds about missing kernel support. The available sinks are also
determined by the hardware so mention that too.

Also, usually it's not necessary to specify the sink, so add that as a
hint.

Now the error for a made up sink looks like this:

  $ perf record -e cs_etm/@abc/
  Couldn't find sink "abc" on event cs_etm/@abc/.
  Missing kernel or device support?

  Hint: An appropriate sink will be picked automatically if one isn't is specified.

For any error other than ENOENT, the same message as before is
displayed.

Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/ec7502e6-b406-3997-c2a5-24f98e5c4854@arm.com
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230124110220.460551-1-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Ian has been reviewing perf tooling patches consistently for a long
time, so lets reflect that in the MAINTAINERS file so that contributors
add him to the CC list in patch submissions.

Reviewed-by: Ian Rogers <irogers@google.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The perf test named “build id cache operations” skips with below error
on some distros:

  <<>>
   78: build id cache operations                                       :
  test child forked, pid 111101
  WARNING: wine not found. PE binaries will not be run.
  test binaries: /tmp/perf.ex.SHA1.PKz /tmp/perf.ex.MD5.Gt3 ./tests/shell/../pe-file.exe
  DEBUGINFOD_URLS=
  Adding 4abd406f041feb4f10ecde3fc30fd0639e1a91cb /tmp/perf.ex.SHA1.PKz: Ok
  build id: 4abd406f041feb4f10ecde3fc30fd0639e1a91cb
  ./tests/shell/buildid.sh: 69: ./tests/shell/buildid.sh: Bad substitution
  test child finished with -2
  build id cache operations: Skip
  <<>>

The test script "tests/shell/buildid.sh" uses some of the string
substitution ways which are supported in bash, but not in "sh" or other
shells. Above error on line number 69 that reports "Bad substitution"
is:

  <<>>
  link=${build_id_dir}/.build-id/${id:0:2}/${id:2}
  <<>>

Here the way of getting first two characters from id ie, ${id:0:2} and
similarly expressions like ${id:2} is not recognised in "sh". So the
line errors and instead of hitting failure, the test gets skipped as
shown in logs.  So the syntax issue causes test not to be executed in
such cases. Similarly usage : "${@: -1}" [ to pick last argument passed
to a function] in “test_record” doesn’t work in all distros.

Fix this by using alternative way with shell substitution to pick
required characters from the string. Also fix the usage of “${@: -1}” to
work in all cases.

Another usage in “test_record” is:

  <<>>
  ${perf} record --buildid-all -o ${data} $@ &> ${log}
  <<>>

This causes the 'perf record' to start in background and Results in the
data file not being created by the time "check" function is invoked.
Below log shows 'perf record' result getting displayed after the call to
"check" function.

  <<>>
  running: perf record /tmp/perf.ex.SHA1.EAU
  build id: 4abd406f041feb4f10ecde3fc30fd0639e1a91cb
  link: /tmp/perf.debug.mLT/.build-id/4a/bd406f041feb4f10ecde3fc30fd0639e1a91cb
  failed: link /tmp/perf.debug.mLT/.build-id/4a/bd406f041feb4f10ecde3fc30fd0639e1a91cb does not exist
  test child finished with -1
  build id cache operations: FAILED!
  root@machine:~/athira/linux/tools/perf# Couldn't synthesize bpf events.
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.010 MB /tmp/perf.data.bFF ]
  <<>>

Fix this by redirecting output instead of using “&” which starts the
command in background.

Reviewed-by: David Laight <David.Laight@ACULAB.COM>
Signed-off-by: Athira Jajeev <atrajeev@linux.vnet.ibm.com>
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nageswara R Sastry <rnsastry@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: linuxppc-dev@lists.ozlabs.org
Link: https://lore.kernel.org/r/20230119142719.32628-1-atrajeev@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Fix various spelling errors as reported by Debian's lintian tool.

"amount of times" -> "number of times"
ocurrence -> occurrence
upto -> up to

Signed-off-by: Diederik de Haas <didi.debian@cknow.org>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230122122034.48020-1-didi.debian@cknow.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

BPF filtering tests can sometime fail. Running the test in verbose mode
shows the following:

  $ sudo perf test 42
  42: BPF filter                                                      :
  42.1: Basic BPF filtering                                           : FAILED!
  42.2: BPF pinning                                                   : Skip
  42.3: BPF prologue generation                                       : Skip
  $ perf --version
  perf version 4.18.0-425.3.1.el8.ppc64le
  $ sudo perf test -v 42
  42: BPF filter                                                      :
  42.1: Basic BPF filtering                                           :
  --- start ---
  test child forked, pid 711060
  ...
  bpf: config 'func=do_epoll_wait' is ok
  Looking at the vmlinux_path (8 entries long)
  Using /usr/lib/debug/lib/modules/4.18.0-425.3.1.el8.ppc64le/vmlinux for symbols
  Open Debuginfo file: /usr/lib/debug/.build-id/81/56f5a07f92ccb62c5600ba0e4aacfb5f3a7534.debug
  Try to find probe point from debuginfo.
  Matched function: do_epoll_wait [4ef8cb0]
  found inline addr: 0xc00000000061dbe4
  Probe point found: __se_compat_sys_epoll_pwait+196
  found inline addr: 0xc00000000061d9f4
  Probe point found: __se_sys_epoll_pwait+196
  found inline addr: 0xc00000000061d824
  Probe point found: __se_sys_epoll_wait+36
  Found 3 probe_trace_events.
  Opening /sys/kernel/tracing//kprobe_events write=1
  ...
  BPF filter result incorrect, expected 56, got 56 samples
  test child finished with -1
  ---- end ----
  BPF filter subtest 1: FAILED!

The statement above about the result being incorrect looks weird, and it
is due to that particular perf build missing commit 3e11300c
("perf test: Fix bpf test sample mismatch reporting"). In reality, due
to commit 4b04e0de

 ("perf test: Fix basic bpf filtering test"),
perf expects there to be 56*3 samples.

However, the number of samples we receive is going to be dependent on
where the probes are installed, which is dependent on where
do_epoll_wait gets inlined. On s390x, it looks like probes at all the
inlined locations are hit. But, that is not the case on ppc64le.

Fix this by switching the test to instead use the syscall tracepoint.
This ensures that we will only ever install a single event enabling us
to reliably determine the sample count.

Reported-by: Disha Goel <disgoel@linux.vnet.ibm.com>
Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Kajol Jain <kjain@linux.ibm.com>
Cc: bpf@vger.kernel.org
Link: http://lore.kernel.org/lkml/20230123083224.276404-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To pick fixes that went via perf/urgent.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

There are some edge cases around estimated timestamps that can result
in them going backwards.

One is that after a discontinuity, the last used timestamp is set to 0.
The duration of the next range is then subtracted which could result in
an earlier timestamp than the last instruction. Fix this by not
resetting the last timestamp used on a discontinuity, and make sure that
new estimated timestamps are clamped to be later than that.

Another case is that estimated timestamps could compound over time to
end up being more than the next real timestamp in the trace. Fix this by
clamping the estimates in cs_etm_decoder__do_soft_timestamp() to be no
later than it.

cs_etm_decoder__do_soft_timestamp() also updated next_cs_timestamp,
which meant that the next real timestamp was lost and not stored
anywhere. Fix that by only updating cs_timestamp for estimates and keep
next_cs_timestamp untouched.

Finally, use next_cs_timestamp to signify if a timestamp has been
received previously. Because cs_timestamp has the first range
subtracted, it could technically go to 0 which would break the logic.

Testing
=======

It can be verified that timestamps don't go backwards when tracing on a
single core with the following commands. Across multiple cores it's
expected that timestamps are interleaved:

  $ perf record -e cs_etm/@tmc_etr0/k -C 4 taskset -c 4 sleep 1
  $ perf script --itrace=i1ns --ns -Fcomm,tid,pid,time,cpu,event,ip,sym,addr,symoff,flags,callindent > itrace
  $ sed 's/://g' itrace | awk -F ' ' ' { print $4 } ' | awk '{ if ($1 < prev) { print "line:" NR " " $0 } {prev=$1}}'

Reported-by: Tanmay Jagdale <tanmay@marvell.com>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-9-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

If virtual timestamps are detected, set sample time field accordingly,
otherwise warn the user that the samples will not include accurate
time data.

  | Test notes (FEAT_TRF platform)
  |
  | $ ./perf record -e cs_etm//u -a -- sleep 4
  | $ ./perf script --fields +time
  | 	    perf   422 [000]   163.375100:          1 branches:uH:                 0 [unknown] ([unknown])
  | 	    perf   422 [000]   163.375100:          1 branches:uH:      ffffb8009544 ioctl+0x14 (/lib/aarch64-linux-gnu/libc-2.27.so)
  | 	    perf   422 [000]   163.375100:          1 branches:uH:      aaaaab6bebf4 perf_evsel__run_ioctl+0x90 (/home/german/linux/tools/perf/perf)
  | [...]
  | 	    perf   422 [000]   167.393100:          1 branches:uH:      aaaaab6bda00 __xyarray__entry+0x74 (/home/german/linux/tools/perf/perf)
  | 	    perf   422 [000]   167.393099:          1 branches:uH:      aaaaab6bda0c __xyarray__entry+0x80 (/home/german/linux/tools/perf/perf)
  | 	    perf   422 [000]   167.393099:          1 branches:uH:      ffffb8009538 ioctl+0x8 (/lib/aarch64-linux-gnu/libc-2.27.so)
  |
  | The time from the first sample to the last sample is 4 seconds

Now that times are converted to nanoseconds, also try to estimate the
timestamps more accurately be dividing by some fixed value for
instructions per ns. This prevents long ranges from being estimated
too far in the past than would be realistic.

Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-8-james.clark@arm.com
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Read the value of ts_source exposed by the driver and store it in the
ETMv4 and ETE header. If the interface doesn't exist (such as in older
Kernels), defaults to a safe value of -1.

Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-7-james.clark@arm.com
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Previously, adding a new parameter at the end of ETMv4 meant adding it
somewhere in the middle of ETE, which is not supported by the current
header version.

Reviewed-by: Mike Leach <mike.leach@linaro.org>
Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-6-james.clark@arm.com
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add a utility function perf_pmu__file_exists() to check if a given pmu
file exists in the sysfs filesystem.

Signed-off-by: German Gomez <german.gomez@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-5-james.clark@arm.com
Signed-off-by: James Clark <james.clark@arm.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Use the new perf_pmu__pathname_scnprintf() instead. No functional
changes.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-4-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Remove some code that duplicates existing methods. Copy strings where
const strings are required.

No functional changes.

Committer notes:

Add a stub for erf_pmu__scan_file() in tools/perf/util/python.c not to
drag tools/perf/util/pmu.c into the python binding.

This fixes 'perf test python' at this point in this patchset.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-3-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The pattern for accessing EVENT_SOURCE_DEVICE_PATH is duplicated in a
few places, so add two utility functions to cover it. Also just use
perf_pmu__scan_file() instead of pmu_type() which already does the same
thing.

No functional changes.

Reviewed-by: Leo Yan <leo.yan@linaro.org>
Signed-off-by: James Clark <james.clark@arm.com>
Acked-by: Suzuki Poulouse <suzuki.poulose@arm.com>
Tested-by: Tanmay Jagdale <tanmay@marvell.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Bharat Bhushan <bbhushan2@marvell.com>
Cc: George Cherian <gcherian@marvell.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: John Garry <john.g.garry@oracle.com>
Cc: Linu Cherian <lcherian@marvell.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sunil Kovvuri Goutham <sgoutham@marvell.com>
Cc: Will Deacon <will@kernel.org>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20230120143702.4035046-2-james.clark@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

In the context of LBR stitching documentation.

Signed-off-by: Ian Rogers <irogers@google.com>
Acked-by: Kan Liang <kan.liang@linux.intel.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Sandipan Das <sandipan.das@amd.com>
Link: https://lore.kernel.org/r/20230119201036.156441-1-irogers@google.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Make the code more readable by checking for SHT_RELA and SHT_REL type
earlier.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-11-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

SHT_REL and SHT_RELA are handled the same way. Simplify by combining the
handling.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-10-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Create a sensible name for .plt entries with no symbol.

Example:

 Before:

   $ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp1.txt

 After:

   $ perf test --dso /usr/lib/x86_64-linux-gnu/libc.so.6 -vv Symbols 2>/tmp/cmp2.txt
   $ diff /tmp/cmp1.txt /tmp/cmp2.txt
    4c4
    < test child forked, pid 53043
    ---
    > test child forked, pid 54372
    23,62c23,62
    <  280f0-28100 g @plt
    <  28100-28110 g @plt
    <  28110-28120 g @plt
    <  28120-28130 g @plt
    <  28130-28140 g @plt
    <  28140-28150 g @plt
    <  28150-28160 g @plt
    <  28160-28170 g @plt
    <  28170-28180 g @plt
    <  28180-28190 g @plt
    <  28190-281a0 g @plt
    <  281a0-281b0 g @plt
    <  281b0-281c0 g @plt
    <  281c0-281d0 g @plt
    <  281d0-281e0 g @plt
    <  281e0-281f0 g @plt
    <  281f0-28200 g @plt
    <  28200-28210 g @plt
    <  28210-28220 g @plt
    <  28220-28230 g @plt
    <  28230-28240 g @plt
    <  28240-28250 g @plt
    <  28250-28260 g @plt
    <  28260-28270 g @plt
    <  28270-28280 g @plt
    <  28280-28290 g @plt
    <  28290-282a0 g @plt
    <  282a0-282b0 g @plt
    <  282b0-282c0 g @plt
    <  282c0-282d0 g @plt
    <  282d0-282e0 g @plt
    <  282e0-282f0 g @plt
    <  282f0-28300 g @plt
    <  28300-28310 g @plt
    <  28310-28320 g @plt
    <  28320-28330 g @plt
    <  28330-28340 g @plt
    <  28340-28350 g @plt
    <  28350-28360 g @plt
    <  28360-28370 g @plt
    ---
    >  280f0-28100 g offset_0x280f0@plt
    >  28100-28110 g offset_0x28100@plt
    >  28110-28120 g offset_0x28110@plt
    >  28120-28130 g offset_0x28120@plt
    >  28130-28140 g offset_0x28130@plt
    >  28140-28150 g offset_0x28140@plt
    >  28150-28160 g offset_0x28150@plt
    >  28160-28170 g offset_0x28160@plt
    >  28170-28180 g offset_0x28170@plt
    >  28180-28190 g offset_0x28180@plt
    >  28190-281a0 g offset_0x28190@plt
    >  281a0-281b0 g offset_0x281a0@plt
    >  281b0-281c0 g offset_0x281b0@plt
    >  281c0-281d0 g offset_0x281c0@plt
    >  281d0-281e0 g offset_0x281d0@plt
    >  281e0-281f0 g offset_0x281e0@plt
    >  281f0-28200 g offset_0x281f0@plt
    >  28200-28210 g offset_0x28200@plt
    >  28210-28220 g offset_0x28210@plt
    >  28220-28230 g offset_0x28220@plt
    >  28230-28240 g offset_0x28230@plt
    >  28240-28250 g offset_0x28240@plt
    >  28250-28260 g offset_0x28250@plt
    >  28260-28270 g offset_0x28260@plt
    >  28270-28280 g offset_0x28270@plt
    >  28280-28290 g offset_0x28280@plt
    >  28290-282a0 g offset_0x28290@plt
    >  282a0-282b0 g offset_0x282a0@plt
    >  282b0-282c0 g offset_0x282b0@plt
    >  282c0-282d0 g offset_0x282c0@plt
    >  282d0-282e0 g offset_0x282d0@plt
    >  282e0-282f0 g offset_0x282e0@plt
    >  282f0-28300 g offset_0x282f0@plt
    >  28300-28310 g offset_0x28300@plt
    >  28310-28320 g offset_0x28310@plt
    >  28320-28330 g offset_0x28320@plt
    >  28330-28340 g offset_0x28330@plt
    >  28340-28350 g offset_0x28340@plt
    >  28350-28360 g offset_0x28350@plt
    >  28360-28370 g offset_0x28360@plt

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-9-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

perf expands the _init symbol over .plt because there are no PLT symbols
at that point, but then dso__synthesize_plt_symbols() creates them.

Fix by truncating the previous symbol and inserting a symbol for .plt
header.

Example:

 Before:

   $ perf test --dso `which uname` -v Symbols
    74: Symbols                                                         :
   --- start ---
   test child forked, pid 191028
   Problems creating module maps, continuing anyway...
   Testing /usr/bin/uname
   Overlapping symbols:
    2000-25f0 g _init
    2040-2050 g free@plt
   test child finished with -1
   ---- end ----
   Symbols: FAILED!
   $ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp1.txt

 After:

   $ perf test --dso `which uname` -v Symbols
    74: Symbols                                                         :
   --- start ---
   test child forked, pid 194291
   Testing /usr/bin/uname
   test child finished with 0
   ---- end ----
   Symbols: Ok
   $ perf test --dso `which uname` -vv Symbols 2>/tmp/cmp2.txt
   $ diff /tmp/cmp1.txt /tmp/cmp2.txt
   4,5c4
   < test child forked, pid 191031
   < Problems creating module maps, continuing anyway...
   ---
   > test child forked, pid 194296
   9c8,9
   <  2000-25f0 g _init
   ---
   >  2000-2030 g _init
   >  2030-2040 g .plt
   100,103c100
   < Overlapping symbols:
   <  2000-25f0 g _init
   <  2040-2050 g free@plt
   < test child finished with -1
   ---
   > test child finished with 0
   105c102
   < Symbols: FAILED!
   ---
   > Symbols: Ok
   $

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-8-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

ss->dynsym is checked to be not NULL twice. Remove the first check
because, in fact, there can be a plt with no dynsym, which is something
that will be dealt with later.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-7-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Return zero directly instead of needless 'goto out_elf_end' that does
the same thing. That allows 'err' to be initialized to -1 instead of
having to change its value later.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-6-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Symbols should not be cached when there are more symbols still to add.

Add dso__find_symbol_nocache() to facilitate that.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-5-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The code expects non-zero plt_entry_size. Check it and add a debug
message to print if it is zero.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-4-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Factor out get_plt_sizes() to make the code more readable and further
changes to dso__synthesize_plt_symbols() easier to follow.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-3-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Add a test to check function symbols do not overlap and are not zero
length.

The main motivation for the test is to make it easier to review changes
to PLT symbol synthesis i.e. changes to dso__synthesize_plt_symbols().

By default the test uses the perf executable as a test DSO, but a
specific DSO can be specified via a new perf test option "--dso".

The test is useful in the following ways:

 - Any DSO can be tested, even ones that do not run on the current
 architecture. For example, using cross-compiled DSOs to see how
 well perf handles different architectures.

 - With verbose > 1 (e.g. -vv), all the symbols are printed, which
 makes it easier to see issues.

 - perf removes duplicate symbols and expands zero-length symbols
 to reach the next symbol, however that is done before adding
 synthesized symbols, so the test is checking those also.

Example:

  $ perf test -v Symbols
   74: Symbols                                                         :
  --- start ---
  test child forked, pid 154918
  Testing /home/user/bin/perf
  Overlapping symbols:
   7d000-7f3a0 g _init
   7d030-7d040 g __printf_chk@plt
  test child finished with -1
  ---- end ----
  Symbols: FAILED!

Note the test fails because perf expands the _init symbol over the PLT
because there are no PLT symbols at that point, but then
dso__synthesize_plt_symbols() creates them.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lore.kernel.org/r/20230120123456.12449-2-adrian.hunter@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Pull scheduler fixes from Borislav Petkov:

 - Make sure the scheduler doesn't use stale frequency scaling values
   when latter get disabled due to a value error

 - Fix a NULL pointer access on UP configs

 - Use the proper locking when updating CPU capacity

* tag 'sched_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/aperfmperf: Erase stale arch_freq_scale values when disabling frequency invariance readings
  sched/core: Fix NULL pointer access fault in sched_setaffinity() with non-SMP configs
  sched/fair: Fixes for capacity inversion detection
  sched/uclamp: Fix a uninitialized variable warnings

Pull EDAC fixes from Borislav Petkov:

 - Respect user-supplied polling value in the EDAC device code

 - Fix a use-after-free issue in qcom_edac

* tag 'edac_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
  EDAC/qcom: Do not pass llcc_driv_data as edac_device_ctl_info's pvt_info
  EDAC/device: Respect any driver-supplied workqueue polling value

Pull perf fix from Borislav Petkov:

 - Add Emerald Rapids model support to more perf machinery

* tag 'perf_urgent_for_v6.2_rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86/intel/cstate: Add Emerald Rapids
  perf/x86/intel: Add Emerald Rapids

Pull gfs2 writepage fix from Andreas Gruenbacher:

 - Fix a regression introduced by commit "gfs2: stop using
   generic_writepages in gfs2_ail1_start_one".

* tag 'gfs2-v6.2-rc4-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
  Revert "gfs2: stop using generic_writepages in gfs2_ail1_start_one"

Commit b2b0a5e9 switched from generic_writepages() to
filemap_fdatawrite_wbc() in gfs2_ail1_start_one() on the path to
replacing ->writepage() with ->writepages() and eventually eliminating
the former.  Function gfs2_ail1_start_one() is called from
gfs2_log_flush(), our main function for flushing the filesystem log.

Unfortunately, at least as implemented today, ->writepage() and
->writepages() are entirely different operations for journaled data
inodes: while the former creates and submits transactions covering the
data to be written, the latter flushes dirty buffers out to disk.

With gfs2_ail1_start_one() now calling ->writepages(), we end up
creating filesystem transactions while we are in the course of a log
flush, which immediately deadlocks on the sdp->sd_log_flush_lock
semaphore.

Work around that by going back to how things used to work before commit
b2b0a5e9 for now; figuring out a superior solution will take time we
don't have available right now.  However ...

Since the removal of generic_writepages() is imminent, open-code it
here.  We're already inside a blk_start_plug() ...  blk_finish_plug()
section here, so skip that part of the original generic_writepages().

This reverts commit b2b0a5e9

.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>