Merge tag 'perf-core-for-mingo-4.21-20181218' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core

Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo:

- Implement BPF based syscall filtering in 'perf trace', using BPF maps and
  the augmented_raw_syscalls.c BPF proggie (Arnaldo Carvalho de Melo)

- Allow specifying in .perfconfig a set of events use in 'perf trace' in
  addition to any other specified from the command line. This initially
  will be used to always use the augmented_raw_syscalls.o precompiled
  BPF program for getting pointer contents. (Arnaldo Carvalho de Melo)

- Allow fine grained control about how the syscall output should be
  formatted. This will be used to allow producing the same output produced
  by the 'strace' tool, to then use in regression tests comparing the
  output of 'perf trace' with the one produced from 'strace' (Arnaldo Carvalho de Melo)

- Beautify the renameat2 olddirfd, newdirfd and flags arguments (Arnaldo Carvalho de Melo)

- Beautify arch_prctl 'code' syscall arg (Arnaldo Carvalho de Melo)

- Beautify fadvise64 'advice' syscall arg (Arnaldo Carvalho de Melo)

- Relax checks on perf-PID.map ownership, resulting in symbols in
  executable anonymous maps setup by JITs in things like node.js to
  be resolved in a 'perf top' session run by root without the need
  for --force to be used (Arnaldo Carvalho de Melo)

- Update asm-generic/unistd.h copy (Arnaldo Carvalho de Melo)

- Do not use the first and last symbols when setting up address filters in
  auxtrace, this fails when we don't have a symbol table, filter the entire
  area based on the dso size. (Adrian Hunter)

- Do not use kernel headers to build libsubcmd, we shouldn't use
  anything from outside tools/, fixes the build with the Android NDK (Arnaldo Carvalho de Melo)

- Add several prototypes for systems lacking those, such as open_memstream(),
  sigqueue(), fixing warnings building with Android's bionic libc that were
  preventing the use of -Werror there (Arnaldo Carvalho de Melo)

- Use LDFLAGS in the libtraceevent build commands, allowing developers
  to override its values (Jiri Olsa)

- Link libperf-jvmti.so with LDFLAGS variable, allowing distro
  packages to propagate its settings when building this library (Jiri Olsa)

- cs-etm (ARM CoreSight) fixes: (Leo Yan)

  - Correct packets swapping in cs_etm__flush()
  - Avoid stale branch samples when flush packet
  - Remove unused 'trace_on' in cs_etm_decoder
  - Refactor enumeration cs_etm_sample_type
  - Rename CS_ETM_TRACE_ON to CS_ETM_DISCONTINUITY
  - Treat NO_SYNC element as trace discontinuity
  - Treat EO_TRACE element as trace discontinuity
  - Generate branch sample for exception packet

- Use shebangs in the 'perf test' shell scripts, making them identifiable as
  shell scripts (Michael Petlan)

- Avoid segfaults caused by negated options in 'perf stat' (Michael Petlan)

- Fix processing of dereferenced args in bprintk events in libtracevent (Steven Rostedt)
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

To get the change in:

  b7d624ab ("asm-generic: unistd.h: fixup broken macro include.")

That doesn't imply in any changes in the tools.

This silences the following perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/asm-generic/unistd.h' differs from latest version at 'include/uapi/asm-generic/unistd.h'
  diff -u tools/include/uapi/asm-generic/unistd.h include/uapi/asm-generic/unistd.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Guo Ren <ren_guo@c-sky.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-2e7xwm5i2qcc88jp2lyawdyd@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Those are simple enough, and usually not produced by root, instead by
whatever user is running java, rust, Node.js JIT code that end up
generating those /tmp/perf-PID.map for resolution of symbols in the
anonymous executable maps.

Having to use --force to resolve symbols in 'perf top' is a distraction,
as recently I experienced when node.js symbols were not being resolved
by 'perf top'.
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Hítalo Silva <hitalos@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/n/tip-tk2jgo2v4v2yjuj28axbpppo@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

That ends up generating this:

  $ cat /tmp/build/perf/trace/beauty/generated/fadvise_advice_array.c
  static const char *fadvise_advices[] = {
	[0] = "NORMAL",
	[1] = "RANDOM",
	[2] = "SEQUENTIAL",
	[3] = "WILLNEED",
	[4] = "DONTNEED",
	[5] = "NOREUSE",
  };
$

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-zwbslubagram8a8zdc003u8h@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

  $ tools/perf/trace/beauty/fadvise.sh
  static const char *fadvise_advices[] = {
	[0] = "NORMAL",
	[1] = "RANDOM",
	[2] = "SEQUENTIAL",
	[3] = "WILLNEED",
	[4] = "DONTNEED",
	[5] = "NOREUSE",
  };
  $

This has a hack wrt the s390 difference.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-tb7jguv01u8p570piq13eioh@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Will be used to generate the string table for fadvise64's 'advice'
argument.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-muswpnft8q9krktv052yrgsc@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Also to make it match 'strace' output, for regression testing.

Both now produce this option, when 'perf trace' uses a .perfconfig
asking for the strace like output:

  mmap(0x7faf66e6a000, 1363968, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x22000) = 0x7faf66e6a000

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-27qhouo1kaac2iyl85nfnsf5@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Helps with comparing 'strace' and 'perf trace' output, for mutual
regression testing.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-va0qe95xbhep5hy52aq5qe0v@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This actually so far, AFAIK is available only in x86, so the code was
put in place with x86 prefixes, in arches where it is not available it
will just not be called, so no further mechanisms are needed at this
time.

Later, when other arches wire this up, we'll just look at the uname
(live sessions) or perf_env data in the perf.data header to auto-wire
the right beautifier.

With this the output is the same as produced by 'strace' when used with
the following ~/.perfconfig:

  # cat ~/.perfconfig
  [llvm]
	dump-obj = true
  [trace]
	  add_events = /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
	  show_zeros = yes
	  show_duration = no
	  no_inherit = yes
	  show_timestamp = no
	  show_arg_names = no
	  args_alignment = -40
	  show_prefix = yes
  #

And, on fedora 29, since the string tables are generated from the kernel
sources, we don't know about 0x3001, just like strace:

  --- /tmp/strace 2018-12-17 11:22:08.707586721 -0300
  +++ /tmp/trace  2018-12-18 11:11:32.037512729 -0300
  @@ -1,49 +1,49 @@
  -arch_prctl(0x3001 /* ARCH_??? */, 0x7ffc8a92dc80) = -1 EINVAL (Invalid argument)
  +arch_prctl(0x3001 /* ARCH_??? */, 0x7ffe4eb93ae0) = -1 EINVAL (Invalid argument)
  -arch_prctl(ARCH_SET_FS, 0x7faf6700f540) = 0
  +arch_prctl(ARCH_SET_FS, 0x7fb507364540) = 0

And that seems to be related to the CET/Shadow Stack feature, that
userland in Fedora 29 (glibc 2.28) are querying the kernel about, that
0x3001 seems to be ARCH_CET_STATUS, I'll check the situation and test
with a fedora 29 kernel to see if the other codes are used.

A diff that ignores the different pointers for different runs needs to
be put in place in the upcoming regression tests comparing 'perf trace's
output to strace's.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-73a9prs8ktkrt97trtdmdjs8@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To match 'strace' output, like in:

  arch_prctl(0x3001 /* ARCH_??? */, 0x7ffc8a92dc80) = -1 EINVAL (Invalid argument)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-kx59j2dk5l1x04ou57mt99ck@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We'll use it in the upcoming arch_prctl() 'code' arg beautifier.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-6e4tj2fjen8qa73gy4u49vav@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

  $ cat /tmp/build/perf/trace/beauty/generated/x86_arch_prctl_code_array.c
  #define x86_arch_prctl_codes_1_offset 0x1001
  static const char *x86_arch_prctl_codes_1[] = {
	[0x1001 - 0x1001]= "SET_GS",
	[0x1002 - 0x1001]= "SET_FS",
	[0x1003 - 0x1001]= "GET_FS",
	[0x1004 - 0x1001]= "GET_GS",
	[0x1011 - 0x1001]= "GET_CPUID",
	[0x1012 - 0x1001]= "SET_CPUID",
  };

  #define x86_arch_prctl_codes_2_offset 0x2001
  static const char *x86_arch_prctl_codes_2[] = {
	[0x2001 - 0x2001]= "MAP_VDSO_X32",
	[0x2002 - 0x2001]= "MAP_VDSO_32",
	[0x2003 - 0x2001]= "MAP_VDSO_64",
  };
  $

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-3r9blij6n8wdlsyd5dujx86r@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

  $ tools/perf/trace/beauty/x86_arch_prctl.sh
  #define x86_arch_prctl_codes_1_offset 0x1001
  static const char *x86_arch_prctl_codes_1[] = {
	[0x1001 - 0x1001]= "SET_GS",
	[0x1002 - 0x1001]= "SET_FS",
	[0x1003 - 0x1001]= "GET_FS",
	[0x1004 - 0x1001]= "GET_GS",
	[0x1011 - 0x1001]= "GET_CPUID",
	[0x1012 - 0x1001]= "SET_CPUID",
  };

  #define x86_arch_prctl_codes_2_offset 0x2001
  static const char *x86_arch_prctl_codes_2[] = {
	[0x2001 - 0x2001]= "MAP_VDSO_X32",
	[0x2002 - 0x2001]= "MAP_VDSO_32",
	[0x2003 - 0x2001]= "MAP_VDSO_64",
  };
  $

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-w0fux1psivphhx6rve8kn3vq@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We need it to generate the tables for the 'code' arch_prctl's syscall
argument.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-vu890pi18fpd4eyz61cazckj@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Matching strace's output format. The 'format' file for the syscall
tracepoints have an indication if the arg is a pointer, with some
exceptions like 'mmap' that has its first arg as an 'unsigned long', so
use a heuristic using the argument name, i.e. if it contains the 'addr'
substring, format it with the pointer formatter.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ddghemr8qrm6i0sb8awznbze@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To match strace, now both emit the same line for calls like:

 access("/etc/ld.so.preload", R_OK)      = -1 ENOENT (No such file or directory)

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-krxl6klsqc9qyktoaxyih942@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

This will all come from userspace, but to test the changes to make 'perf
trace' output similar to strace's, do this one more now manually.

To update the precompiled augmented_raw_syscalls.o binary I just run:

  # perf record -e ~acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.c sleep 1
  LLVM: dumping /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.022 MB perf.data ]
  #

Because to have augmented_raw_syscalls to be always used and a fast
startup and remove the need to have the llvm toolchain installed, I'm
using:

  # perf config | grep add_events
  trace.add_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  #

So when doing changes to augmented_raw_syscals.c one needs to rebuild
the .o file.

This will be done automagically later, i.e. have a 'make' behaviour of
recompiling when the .c gets changed.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-lw3i2atyq8549fpqwmszn3qp@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To use strace's style, helping in comparing the output of 'perf trace'
with the one from 'strace', to help in upcoming regression tests.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-mw6peotz4n84rga0fk78buff@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

And there are more flags, to match strace's output.

 openat(AT_FDCWD, "/etc/ld.so.cache", O_RDONLY|O_CLOEXEC) = 3

Also to help with regression tests.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ofovpmvdli3bwch30936xn7t@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

So far we've been suppressing common stuff such as "MAP_" in the mmap
flags, showing "SHARED" instead of "MAP_SHARED", allow for those
prefixes (and a few suffixes) to be shown:

  # trace -e *map,open*,*seek sleep 1
  openat("/etc/ld.so.cache", CLOEXEC) = 3
  mmap(0, 109093, READ, PRIVATE, 3, 0) = 0x7ff61c695000
  openat("/lib64/libc.so.6", CLOEXEC) = 3
  lseek(3, 792, SET) = 792
  mmap(0, 8192, READ|WRITE, PRIVATE|ANONYMOUS) = 0x7ff61c693000
  lseek(3, 792, SET) = 792
  lseek(3, 864, SET) = 864
  mmap(0, 1857568, READ, PRIVATE|DENYWRITE, 3, 0) = 0x7ff61c4cd000
  mmap(0x7ff61c4ef000, 1363968, EXEC|READ, PRIVATE|FIXED|DENYWRITE, 3, 139264) = 0x7ff61c4ef000
  mmap(0x7ff61c63c000, 311296, READ, PRIVATE|FIXED|DENYWRITE, 3, 1503232) = 0x7ff61c63c000
  mmap(0x7ff61c689000, 24576, READ|WRITE, PRIVATE|FIXED|DENYWRITE, 3, 1814528) = 0x7ff61c689000
  mmap(0x7ff61c68f000, 14368, READ|WRITE, PRIVATE|FIXED|ANONYMOUS) = 0x7ff61c68f000
  munmap(0x7ff61c695000, 109093) = 0
  openat("/usr/lib/locale/locale-archive", CLOEXEC) = 3
  mmap(0, 217749968, READ, PRIVATE, 3, 0) = 0x7ff60f523000
  #
  # vim ~/.perfconfig
  #
  # perf config
  llvm.dump-obj=true
  trace.add_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  trace.show_zeros=yes
  trace.show_duration=no
  trace.no_inherit=yes
  trace.show_timestamp=no
  trace.show_arg_names=no
  trace.args_alignment=0
  trace.string_quote="
  trace.show_prefix=yes
  #
  #
  # trace -e *map,open*,*seek sleep 1
  openat(AT_FDCWD, "/etc/ld.so.cache", O_CLOEXEC) = 3
  mmap(0, 109093, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7ebbe59000
  openat(AT_FDCWD, "/lib64/libc.so.6", O_CLOEXEC) = 3
  lseek(3, 792, SEEK_SET) = 792
  mmap(0, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS) = 0x7f7ebbe57000
  lseek(3, 792, SEEK_SET) = 792
  lseek(3, 864, SEEK_SET) = 864
  mmap(0, 1857568, PROT_READ, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f7ebbc91000
  mmap(0x7f7ebbcb3000, 1363968, PROT_EXEC|PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 139264) = 0x7f7ebbcb3000
  mmap(0x7f7ebbe00000, 311296, PROT_READ, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 1503232) = 0x7f7ebbe00000
  mmap(0x7f7ebbe4d000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 1814528) = 0x7f7ebbe4d000
  mmap(0x7f7ebbe53000, 14368, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS) = 0x7f7ebbe53000
  munmap(0x7f7ebbe59000, 109093) = 0
  openat(AT_FDCWD, "/usr/lib/locale/locale-archive", O_CLOEXEC) = 3
  mmap(0, 217749968, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f7eaece7000
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-mtn1i4rjowjl72trtnbmvjd4@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

So that the user, in an upcoming patch, can select printing it to get
the full string as used in the source code, not one with a common prefix
chopped off so as to make the output more compact.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-zypczc88gzbmeqx7b372s138@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To match 'strace' output, helping with upcoming regression tests
comparing both outputs.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-jab52t1dcuh6vlztqle9g7u9@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

Since the start 'perf trace' aligns the parens enclosing the list of
syscall args to align the syscall results, allow this to be
configurable, keeping the default of 70. Using:

  # perf config
  llvm.dump-obj=true
  trace.add_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  trace.show_zeros=yes
  trace.show_duration=no
  trace.no_inherit=yes
  trace.show_timestamp=no
  trace.show_arg_names=no
  trace.args_alignment=0
  # trace -e open*,close,*sleep sleep 1
  openat(CWD, /etc/ld.so.cache, CLOEXEC) = 3
  close(3) = 0
  openat(CWD, /lib64/libc.so.6, CLOEXEC) = 3
  close(3) = 0
  openat(CWD, /usr/lib/locale/locale-archive, CLOEXEC) = 3
  close(3) = 0
  nanosleep(0x7ffc00de66f0, 0) = 0
  close(1) = 0
  close(2) = 0
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-r8cbhoz1lr5npq9tutpvoigr@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To show just the values:

Default:

  # trace -e open*,close,*sleep sleep 1
  openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC           ) = 3
  close(fd: 3                                                           ) = 0
  openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC           ) = 3
  close(fd: 3                                                           ) = 0
  openat(dfd: CWD, filename: /usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
  close(fd: 3                                                           ) = 0
  nanosleep(rqtp: 0x7ffc0c4ea0d0, rmtp: 0                               ) = 0
  close(fd: 1                                                           ) = 0
  close(fd: 2                                                           ) = 0
  #

Remove it:

  # perf config trace.show_arg_names=no
  # trace -e open*,close,*sleep sleep 1
  openat(CWD, /etc/ld.so.cache, CLOEXEC                                 ) = 3
  close(3                                                               ) = 0
  openat(CWD, /lib64/libc.so.6, CLOEXEC                                 ) = 3
  close(3                                                               ) = 0
  openat(CWD, /usr/lib/locale/locale-archive, CLOEXEC                   ) = 3
  close(3                                                               ) = 0
  nanosleep(0x7ffced3a8c40, 0                                           ) = 0
  close(1                                                               ) = 0
  close(2                                                               ) = 0
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-ta9tbdwgodpw719sr2bjm8eb@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

  # trace -e open*,close,*sleep sleep 1
     0.000 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC           ) = 3
     0.016 close(fd: 3                                                           ) = 0
     0.024 openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC           ) = 3
     0.074 close(fd: 3                                                           ) = 0
     0.235 openat(dfd: CWD, filename: /usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
     0.251 close(fd: 3                                                           ) = 0
     0.285 nanosleep(rqtp: 0x7ffd68e6d620, rmtp: 0                               ) = 0
  1000.386 close(fd: 1                                                           ) = 0
  1000.395 close(fd: 2                                                           ) = 0
  #

  # perf config trace.show_timestamp=no
  # trace -e open*,close,*sleep sleep 1
  openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC           ) = 3
  close(fd: 3                                                           ) = 0
  openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC           ) = 3
  close(fd: 3                                                           ) = 0
  openat(dfd: CWD, filename: , flags: CLOEXEC                           ) = 3
  close(fd: 3                                                           ) = 0
  nanosleep(rqtp: 0x7fffa79c38e0, rmtp: 0                               ) = 0
  close(fd: 1                                                           ) = 0
  close(fd: 2                                                           ) = 0
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-mjjnicy48367jah6ls4k0nk8@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

I.f. if children should inherit the parent perf_event configuration,
i.e. if we should trace children as well or just the parent.

The default is to follow children, to disable this and have a behaviour
similar to strace, set this config option or use the --no_inherit 'perf
trace' option.

E.g.:

Default:

  # perf config trace.no_inherit
  # trace -e clone,*sleep time sleep 1
     0.000 time/21107 clone(clone_flags: CHILD_CLEARTID|CHILD_SETTID|0x11, newsp: 0, child_tidptr: 0x7f7b8f9ae810) = 21108 (time)
         ? time/21108  ... [continued]: clone()
     0.691 sleep/21108 nanosleep(rqtp: 0x7ffed01d0540, rmtp: 0                               ) = 0
  0.00user 0.00system 0:01.00elapsed 0%CPU (0avgtext+0avgdata 1988maxresident)k
  0inputs+0outputs (0major+76minor)pagefaults 0swaps
  #

Disable it:

  # trace -e clone,*sleep time sleep 1
     0.000 clone(clone_flags: CHILD_CLEARTID|CHILD_SETTID|0x11, newsp: 0, child_tidptr: 0x7ff41e100810) = 21414 (time)
  0.00user 0.00system 0:01.00elapsed 0%CPU (0avgtext+0avgdata 1964maxresident)k
  0inputs+0outputs (0major+76minor)pagefaults 0swaps
  #

Notice that since there is just one thread, the "comm/TID" column is
suppressed.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-thd8s16pagyza71ufi5vjlan@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

More convenient thah having to recall what letter is about
showing/listing/dumping the configuration, i.e. no arguments means
-l/--list:

  # perf config
  llvm.dump-obj=true
  trace.default_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  trace.show_zeros=yes
  trace.show_duration=no
  # perf config -l
  llvm.dump-obj=true
  trace.default_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  trace.show_zeros=yes
  trace.show_duration=no
  # perf config -h

   Usage: perf config [<file-option>] [options] [section.name[=value] ...]

      -l, --list            show current config variables
          --system          use system config file
          --user            use user config file

  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-z2n63avz6tliqb5gmu4l1dti@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

  # perf config trace.show_duration=no
  # perf config -l | grep trace
  trace.default_events=/home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  trace.show_zeros=true
  trace.show_duration=no
  # trace -e *sleep sleep 1
     0.000 sleep/8729 nanosleep(rqtp: 0x7ffcb0b4c940, rmtp: 0) = 0
  # perf config trace.show_duration=yes
  # trace -e *sleep sleep 1
     0.000 (1000.212 ms): sleep/8735 nanosleep(rqtp: 0x7ffca15fa770, rmtp: 0) = 0
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-2c7h1m8fhzb9puxtj9nlevi8@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The default so far, since we show argument names followed by its values,
was to make the output more compact by suppressing most zeroed args.

Make this configurable so that users can choose what best suit their
needs.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-q0gxws02ygodh94o0hzim5xd@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

To add augmented_raw_syscalls to the events speficied by the user, or be
the only one if no events were specified by the user, one can add this
to perfconfig:

  # cat ~/.perfconfig
  [trace]
	  add_events = /home/acme/git/perf/tools/perf/examples/bpf/augmented_raw_syscalls.o
  #

I.e. pre-compile the augmented_raw_syscalls.c BPF program and make it
always load, this way:

  # perf trace -e open* cat /etc/passwd > /dev/null
     0.000 ( 0.013 ms): cat/31557 openat(dfd: CWD, filename: /etc/ld.so.cache, flags: CLOEXEC) = 3
     0.035 ( 0.007 ms): cat/31557 openat(dfd: CWD, filename: /lib64/libc.so.6, flags: CLOEXEC) = 3
     0.353 ( 0.009 ms): cat/31557 openat(dfd: CWD, filename: /usr/lib/locale/locale-archive, flags: CLOEXEC) = 3
     0.424 ( 0.006 ms): cat/31557 openat(dfd: CWD, filename: /etc/passwd) = 3
  #

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-0lgj7vh64hg3ce44gsmvj7ud@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We're not using that puts() thing, and thus we don't need to define the
__bpf_stdout__ map, reducing the setup time.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-3452xgatncpil7v22minkwbo@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The exception packet appears as one element with 'elem_type' ==
OCSD_GEN_TRC_ELEM_EXCEPTION or OCSD_GEN_TRC_ELEM_EXCEPTION_RET, which is
present for exception entry and exit respectively.  The decoder sets the
packet fields 'packet->exc' and 'packet->exc_ret' to indicate the
exception packets; but exception packets don't have a dedicated sample
type and shares the same sample type CS_ETM_RANGE with normal
instruction packets.

As a result, the exception packets are taken as normal instruction
packets and this introduces confusion in mixing different packet types.
Furthermore, these instruction range packets will be processed for
branch samples only when 'packet->last_instr_taken_branch' is true,
otherwise they will be omitted, this can introduce a mess for exception
and exception returning due to not having the complete address range
info for context switching.

To process exception packets properly, this patch introduces two new
sample types: CS_ETM_EXCEPTION and CS_ETM_EXCEPTION_RET; these two types
of packets will be handled by cs_etm__exception().  The function
cs_etm__exception() forces setting the previous CS_ETM_RANGE packet flag
'prev_packet->last_instr_taken_branch' to true, this matches well with
the program flow when the exception is trapped from user space to kernel
space, no matter if the most recent flow has branch taken or not; this
is also safe for returning to user space after exception handling.

After exception packets have their own sample type, the packet fields
'packet->exc' and 'packet->exc_ret' aren't needed anymore, so remove
them.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight ml <coresight@lists.linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-9-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

If the decoder outputs an EO_TRACE element, it means the end of the
trace buffer; this is a discontinuity and in this case the end of trace
data needs to be saved.

This patch generates a CS_ETM_DISCONTINUITY packet for the EO_TRACE
element hereby flushing the end of trace data in cs-etm.c.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-8-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The CoreSight tracer driver might insert barrier packets between
different buffers, thus the decoder can spot the boundaries based on the
barrier packet; it is possible for the decoder to hit a barrier packet
and emit a NO_SYNC element, then the decoder will find a periodic
synchronisation point inside that next trace block that starts the trace
again but does not have the TRACE_ON element as indicator - usually
because this trace block has wrapped the buffer so we have lost the
original point when the trace was enabled.

In the first case it causes the insertion of a OCSD_GEN_TRC_ELEM_NO_SYNC
in the middle of the tracing stream, but as we were not handling the
NO_SYNC element properly this ends up making users miss the
discontinuity indications.

Though OCSD_GEN_TRC_ELEM_NO_SYNC is different from CS_ETM_TRACE_ON when
output from the decoder, both indicate that the trace data is
discontinuous; this patch treats OCSD_GEN_TRC_ELEM_NO_SYNC as a trace
discontinuity and generates a CS_ETM_DISCONTINUITY packet for it, so
cs-etm can handle the discontinuity for this case, finally it saves the
last trace data for the previous trace block and restart samples for the
new block.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight ml <coresight@lists.linaro.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-7-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

TRACE_ON element is used at the beginning of trace, it also can be
appeared in the middle of trace data to indicate discontinuity; for
example, it's possible to see multiple TRACE_ON elements in the trace
stream if the trace is being limited by address range filtering.

Furthermore, except TRACE_ON element is for discontinuity, NO_SYNC and
EO_TRACE also can be used to indicate discontinuity, though they are
used for different scenarios for which the trace is interrupted.

This patch renames sample type CS_ETM_TRACE_ON to CS_ETM_DISCONTINUITY,
firstly the new name describes more closely the purpose of the packet;
secondly this is a preparation for other output elements which also
cause the trace discontinuity thus they can share the same one packet
type.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-6-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The values in enumeration cs_etm_sample_type are defined with setting
bit N for each packet type, this is not suggested in the usual case.

This patch refactor cs_etm_sample_type by converting from bit shifting
values to continuous numbers.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-5-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

cs_etm_decoder::trace_on is being assigned when TRACE_ON or NO_SYNC
element is coming, but it is never used hence it is redundant and can
be removed.

So let's remove 'trace_on' field from cs_etm_decoder struct.
Suggested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-4-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

At the end of trace buffer handling, function cs_etm__flush() is invoked
to flush any remaining branch stack entries.  As a side effect, it also
generates branch sample, because the 'etmq->packet' doesn't contains any
new coming packet but point to one stale packet after packets swapping,
so it wrongly makes synthesize branch samples with stale packet info.

We could review below detailed flow which causes issue:

  Packet1: start_addr=0xffff000008b1fbf0 end_addr=0xffff000008b1fbfc
  Packet2: start_addr=0xffff000008b1fb5c end_addr=0xffff000008b1fb6c

  step 1: cs_etm__sample():
	sample: ip=(0xffff000008b1fbfc-4) addr=0xffff000008b1fb5c

  step 2: flush packet in cs_etm__run_decoder():
	cs_etm__run_decoder()
	  `-> err = cs_etm__flush(etmq, false);
	sample: ip=(0xffff000008b1fb6c-4) addr=0xffff000008b1fbf0

Packet1 and packet2 are two continuous packets, when packet2 is the new
coming packet, cs_etm__sample() generates branch sample for these two
packets and use [packet1::end_addr - 4 => packet2::start_addr] as branch
jump flow, thus we can see the first generated branch sample in step 1.
At the end of cs_etm__sample() it swaps packets so 'etm->prev_packet'=
packet2 and 'etm->packet'=packet1, so far it's okay for branch sample.

If packet2 is the last one packet in trace buffer, even there have no
any new coming packet, cs_etm__run_decoder() invokes cs_etm__flush() to
flush branch stack entries as expected, but it also generates branch
samples by taking 'etm->packet' as a new coming packet, thus the branch
jump flow is as [packet2::end_addr - 4 =>  packet1::start_addr]; this
is the second sample which is generated in step 2.  So actually the
second sample is a stale sample and we should not generate it.

This patch introduces a new function cs_etm__end_block(), at the end of
trace block this function is invoked to only flush branch stack entries
and thus can avoid to generate branch sample for stale packet.
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-3-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

The structure cs_etm_queue uses 'prev_packet' to point to previous
packet, this can be used to combine with new coming packet to generate
samples.

In function cs_etm__flush() it swaps packets only when the flag
'etm->synth_opts.last_branch' is true, this means that it will not swap
packets if without option '--itrace=il' to generate last branch entries;
thus for this case the 'prev_packet' doesn't point to the correct
previous packet and the stale packet still will be used to generate
sequential sample.  Thus if dump trace with 'perf script' command we can
see the incorrect flow with the stale packet's address info.

This patch corrects packets swapping in cs_etm__flush(); except using
the flag 'etm->synth_opts.last_branch' it also checks the another flag
'etm->sample_branches', if any flag is true then it swaps packets so can
save correct content to 'prev_packet'.  Finally this can fix the wrong
program flow dumping issue.

The patch has a minor refactoring to use 'etm->synth_opts.last_branch'
instead of 'etmq->etm->synth_opts.last_branch' for condition checking,
this is consistent with that is done in cs_etm__sample().
Signed-off-by: Leo Yan <leo.yan@linaro.org>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Mike Leach <mike.leach@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Robert Walker <robert.walker@arm.com>
Cc: coresight@lists.linaro.org
Cc: linux-arm-kernel@lists.infradead.org
Link: http://lkml.kernel.org/r/1544513908-16805-2-git-send-email-leo.yan@linaro.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

We'll start adding more perf-syscall stuff, so lets do this prep step so
that the next ones are just about adding more fields.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-vac4sn1ns1vj4y07lzj7y4b8@git.kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>