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  1. 28 Dec, 2018 17 commits
  3. 21 Dec, 2018 4 commits
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Do not hardcode the size of the tracepoint common_ fields · b9b6a2ea
      Arnaldo Carvalho de Melo authored 
      We shouldn't hardcode the size of the tracepoint common_ fields, use the
offset of the 'id'/'__syscallnr' field in the sys_enter event instead.

This caused the augmented syscalls code to fail on a particular build of a
PREEMPT_RT_FULL kernel where these extra 'common_migrate_disable' and
'common_padding' fields were before the syscall id one:

  # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/format
  name: sys_enter
  ID: 22
  format:
	field:unsigned short common_type;	offset:0;	size:2;	signed:0;
	field:unsigned char common_flags;	offset:2;	size:1;	signed:0;
	field:unsigned char common_preempt_count;	offset:3;	size:1;	signed:0;
	field:int common_pid;	offset:4;	size:4;	signed:1;
	field:unsigned short common_migrate_disable;	offset:8;	size:2;	signed:0;
	field:unsigned short common_padding;	offset:10;	size:2;	signed:0;

	field:long id;	offset:16;	size:8;	signed:1;
	field:unsigned long args[6];	offset:24;	size:48;	signed:0;

  print fmt: "NR %ld (%lx, %lx, %lx, %lx, %lx, %lx)", REC->id, REC->args[0], REC->args[1], REC->args[2], REC->args[3], REC->args[4], REC->args[5]
  #

All those 'common_' prefixed fields are zeroed when they hit a BPF tracepoint
hook, we better just discard those, i.e. somehow pass an offset to the
BPF program from the start of the ctx and make adjustments in the 'perf trace'
handlers to adjust the offset of the syscall arg offsets obtained from tracefs.

Till then, fix it the quick way and add this to the augmented_raw_syscalls.c to
bet it to work in such kernels:

  diff --git a/tools/perf/examples/bpf/augmented_raw_syscalls.c b/tools/perf/examples/bpf/augmented_raw_syscalls.c
  index 53c233370fae..1f746f931e13 100644
  --- a/tools/perf/examples/bpf/augmented_raw_syscalls.c
  +++ b/tools/perf/examples/bpf/augmented_raw_syscalls.c
  @@ -38,12 +38,14 @@ struct bpf_map SEC("maps") syscalls = {

   struct syscall_enter_args {
          unsigned long long common_tp_fields;
  +       long               rt_common_tp_fields;
          long               syscall_nr;
          unsigned long      args[6];
   };

   struct syscall_exit_args {
          unsigned long long common_tp_fields;
  +       long               rt_common_tp_fields;
          long               syscall_nr;
          long               ret;
   };

Just to check that this was the case. Fix it properly later, for now remove the
hardcoding of the offset in the 'perf trace' side and document the situation
with this patch.

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-2pqavrktqkliu5b9nzouio21@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      b9b6a2ea
    • Stanislav Fomichev's avatar
      perf build: Don't unconditionally link the libbfd feature test to -liberty and -lz · 14541b1e
      Stanislav Fomichev authored 
      Current libbfd feature test unconditionally links against -liberty and -lz.
While it's required on some systems (e.g. opensuse), it's completely
unnecessary on the others, where only -lbdf is sufficient (debian).
This patch streamlines (and renames) the following feature checks:

feature-libbfd           - only link against -lbfd (debian),
                           see commit 2cf90407 ("perf tools: Fix bfd
			   dependency libraries detection")
feature-libbfd-liberty   - link against -lbfd and -liberty
feature-libbfd-liberty-z - link against -lbfd, -liberty and -lz (opensuse),
                           see commit 280e7c48 ("perf tools: fix BFD
			   detection on opensuse")

(feature-liberty{,-z} were renamed to feature-libbfd-liberty{,z}
for clarity)

The main motivation is to fix this feature test for bpftool which is
currently broken on debian (libbfd feature shows OFF, but we still
unconditionally link against -lbfd and it works).

Tested on debian with only -lbfd installed (without -liberty); I'd
appreciate if somebody on the other systems can test this new detection
method.
Signed-off-by: default avatarStanislav Fomichev <sdf@google.com>
Acked-by: default avatarJiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/4dfc634cfcfb236883971b5107cf3c28ec8a31be.1542328222.git.sdf@google.comSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      14541b1e
    • Arnaldo Carvalho de Melo's avatar
      perf beauty mmap: PROT_WRITE should come before PROT_EXEC · 5ce29d52
      Arnaldo Carvalho de Melo authored 
      To match strace output:

  # cat mmap.c
  #include <sys/mman.h>

  int main(void)
  {
	  mmap(0, 4096, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
	  return 0;
  }
  # strace -e mmap ./mmap |& grep -v ^+++
  mmap(NULL, 103484, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f5bae400000
  mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f5bae3fe000
  mmap(NULL, 3889792, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f5bade40000
  mmap(0x7f5bae1ec000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1ac000) = 0x7f5bae1ec000
  mmap(0x7f5bae1f2000, 14976, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0x7f5bae1f2000
  mmap(NULL, 4096, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f5bae419000
  # trace -e mmap ./mmap |& grep -v ^+++
  mmap(NULL, 103484, PROT_READ, MAP_PRIVATE, 3, 0) = 0x7f6646c25000
  mmap(NULL, 8192, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS) = 0x7f6646c23000
  mmap(NULL, 3889792, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0x7f6646665000
  mmap(0x7f6646a11000, 24576, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x1ac000) = 0x7f6646a11000
  mmap(0x7f6646a17000, 14976, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS) = 0x7f6646a17000
  mmap(NULL, 4096, PROT_READ|PROT_WRITE|PROT_EXEC, MAP_PRIVATE|MAP_ANONYMOUS) = 0x7f6646c3e000
  #
Reported-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Luis Cláudio Gonçalves <lclaudio@redhat.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: https://lkml.kernel.org/n/tip-nt49d6iqle80cw8f529ovaqi@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      5ce29d52
    • Arnaldo Carvalho de Melo's avatar
      perf trace: Check if the raw_syscalls:sys_{enter,exit} are setup before setting tp filter · f76214f9
      Arnaldo Carvalho de Melo authored 
      While updating 'perf trace' on an machine with an old precompiled
augmented_raw_syscalls.o that didn't setup the syscall map the new 'perf
trace' codebase notices the augmented_raw_syscalls.o eBPF event, decides
to use it instead of the old raw_syscalls:sys_{enter,exit} method, but
then because we don't have the syscall map tries to set the tracepoint
filter on the sys_{enter,exit} evsels, that are NULL, segfaulting.

Make the code more robust by checking it those tracepoints have
their respective evsels in place before trying to set the tp filter.

With this we still get everything to work, just not setting up the
syscall filters, which is better than a segfault. Now to update the
precompiled augmented_raw_syscalls.o and continue development :-)

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-3ft5rjdl05wgz2pwpx2z8btu@git.kernel.orgSigned-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
      f76214f9
  5. 20 Dec, 2018 1 commit
    • Ingo Molnar's avatar
      Merge tag 'perf-core-for-mingo-4.21-20181218' of... · 883f4def
      Ingo Molnar authored 
      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: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      883f4def
  7. 18 Dec, 2018 18 commits
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