linux-stable.git/tools/perf/tests, branch v4.17.2

perf test: "Session topology" dumps core on s390

2018-05-30T14:43:58+00:00

The "perf test Session topology" entry fails with core dump on s390. The root
cause is a NULL pointer dereference in function check_cpu_topology() line 76
(or line 82 without -v).

The session->header.env.cpu variable is NULL because on s390 function
process_cpu_topology() returns with error:

    socket_id number is too big.
    You may need to upgrade the perf tool.

and releases the env.cpu variable via zfree() and sets it to NULL.

Here is the gdb output:
(gdb) n
76                      pr_debug("CPU %d, core %d, socket %d\n", i,
(gdb) n

Program received signal SIGSEGV, Segmentation fault.
0x00000000010f4d9e in check_cpu_topology (path=0x3ffffffd6c8
	"/tmp/perf-test-J6CHMa", map=0x14a1740) at tests/topology.c:76
76  pr_debug("CPU %d, core %d, socket %d\n", i,
(gdb)

Make sure the env.cpu variable is not used when its NULL.
Test for NULL pointer and return TEST_SKIP if so.

Output before:

  [root@p23lp27 perf]# ./perf test -F 39
  39: Session topology  :Segmentation fault (core dumped)
  [root@p23lp27 perf]#

Output after:

  [root@p23lp27 perf]# ./perf test -vF 39
  39: Session topology                                      :
  --- start ---
  templ file: /tmp/perf-test-Ajx59D
  socket_id number is too big.You may need to upgrade the perf tool.
  ---- end ----
  Session topology: Skip
  [root@p23lp27 perf]#

Signed-off-by: Thomas Richter 
Cc: Heiko Carstens 
Cc: Hendrik Brueckner 
Cc: Martin Schwidefsky 
Link: http://lkml.kernel.org/r/20180528073657.11743-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test: "probe libc's inet_pton" fails on s390 due to missing inline

2018-05-10T18:19:30+00:00

perf test "probe libc's inet_pton & backtrace it with ping" fails on
4.17.0rc3 on s/390. It turned out that function __inet_pton is reported
as inline:

  [root@s8360047 perf]# ./perf script -i /tmp/perf.data.111
  ping 12457 [000]  1584.478959: probe_libc:inet_pton: (3ffb5a347e8)
                    1347e8 __inet_pton (inlined)
                     f19d7 gaih_inet.constprop.5 (/usr/lib64/libc-2.24.so)
                     f4c3f __GI_getaddrinfo (inlined)
                      410b main (/usr/bin/ping)

Allow __inet_pton listed as inline.

Signed-off-by: Thomas Richter 
Cc: Heiko Carstens 
Cc: Hendrik Brueckner 
Cc: Martin Schwidefsky 
Link: http://lkml.kernel.org/r/20180503065837.71043-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf evsel: Disable write_backward for leader sampling group events

2018-04-23T14:21:56+00:00

.. and other related fields that do not need to be enabled
for events that have sampling leader.

It fixes the perf top usage Ingo reported broken:

  # perf top -e '{cycles,msr/aperf/}:S'

The 'msr/aperf/' event is configured for write_back sampling, which is
not allowed by the MSR PMU, so it fails to create the event.

Adjusting related attr test.

Reported-by: Ingo Molnar 
Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Kan Liang 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Link: http://lkml.kernel.org/r/20180423090823.32309-6-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf test: Adapt test case record+probe_libc_inet_pton.sh for s390

2018-04-23T14:04:37+00:00

perf test case 58 (record+probe_libc_inet_pton.sh) executed on s390x
using kernel 4.16.0rc3 displays this result:

 # perf trace --no-syscalls -e probe_libc:inet_pton/call-graph=dwarf/ ping -6 -c 1 ::1
     probe_libc:inet_pton: (3ffa0240448)
	      __GI___inet_pton (/usr/lib64/libc-2.26.so)
	      gaih_inet (inlined)
	      __GI_getaddrinfo (inlined)
	      main (/usr/bin/ping)
	      __libc_start_main (/usr/lib64/libc-2.26.so)
	     _start (/usr/bin/ping)

After I installed kernel 4.16.0 the same tests uses commands:

 # perf record -e probe_libc:inet_pton/call-graph=dwarf/
      -o /tmp/perf.data.abc ping -6 -c 1 ::1
 # perf script -i /tmp/perf.data.abc

and displays:

 ping 39048 [006] 84230.381198: probe_libc:inet_pton: (3ffa0240448)
	       140448 __GI___inet_pton (/usr/lib64/libc-2.26.so)
	       fbde1 gaih_inet (inlined)
	       fe2b9 __GI_getaddrinfo (inlined)
	        398d main (/usr/bin/ping)

Nothing else changed including glibc elfutils and other libraries picked
up by the build.

The entries for __libc_start_main and _start are missing.

I bisected missing __libc_start_main and _start to commit

Fixes: 3d20c6246690 ("perf unwind: Unwind with libdw doesn't take symfs into account")

When I undo this commit I get this call stack on s390:
 [root@s35lp76 perf]# ./perf script  -i /tmp/perf.data.abc
 ping 39048 [006] 84230.381198: probe_libc:inet_pton: (3ffa0240448)
	140448 __GI___inet_pton (/usr/lib64/libc-2.26.so)
	 fbde1 gaih_inet (inlined)
	 fe2b9 __GI_getaddrinfo (inlined)
	  398d main (/usr/bin/ping)
	 22fbd __libc_start_main (/usr/lib64/libc-2.26.so)
	  457b _start (/usr/bin/ping)

Looks like dwarf functions dwfl_xxx create different call back stack
trace when using file /usr/lib/debug/usr/bin/ping-20161105-7.fc27.s390x.debug
instead of file /usr/bin/ping.

Fix this test case on s390 and do not expect any call back stack entry
after the main() function. Also be more robust and accept a leading
__GI_ prefix in front of getaddrinfo.

On x86 this test case shows the same call stack using both kernel
versions 4.16.0rc3 and 4.16.0 and also stops at main:

  [root@f27 perf]# ./perf script -i /tmp/perf.data.tmr
  ping  4446 [000]   172.027088: probe_libc:inet_pton: (7fdfa08c93c0)
	             1393c0 __GI___inet_pton (/usr/lib64/libc-2.26.so)
	              fe60d getaddrinfo (/usr/lib64/libc-2.26.so)
	               2f40 main (/usr/bin/ping)
  [root@f27 perf]#

Signed-off-by: Thomas Richter 
Reviewed-by: Hendrik Brueckner 
Cc: Heiko Carstens 
Cc: Martin Schwidefsky 
Cc: Martin Vuille 
Link: http://lkml.kernel.org/r/20180423082428.7930-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf test BPF: Fixup BPF test using epoll_pwait syscall function probe

2018-04-18T18:35:53+00:00

Since e145242ea0df ("syscalls/core, syscalls/x86: Clean up syscall stub
naming convention") changed the main syscall function for 'epoll_pwait'
to something other than the expected 'SyS_epoll_pwait the' 'perf test
BPF' entries started failing, fix it by using something called from the
main syscall function instead, 'epoll_wait', which should keep this test
working in older kernels too.

Before:

  # perf test BPF
  40: BPF filter                           :
  40.1: Basic BPF filtering                : FAILED!
  40.2: BPF pinning                        : Skip
  40.3: BPF prologue generation            : Skip
  40.4: BPF relocation checker             : Skip

If we use -v for that test we see the problem:

    Probe point 'SyS_epoll_pwait' not found.

After:

  # perf test BPF
  40: BPF filter                           :
  40.1: Basic BPF filtering                : Ok
  40.2: BPF pinning                        : Ok
  40.3: BPF prologue generation            : Ok
  40.4: BPF relocation checker             : Ok
  #

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Dominik Brodowski 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Steven Rostedt 
Cc: Wang Nan 
Link: https://lkml.kernel.org/r/tip-y24nmn70cs2am8jh4i344dng@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tests mmap: Show which tracepoint is failing

2018-04-18T18:35:52+00:00

In the 'perf test "mmap interface"' we try creating events for several
tracepoints, but when perf_evsel__new() fails we're not showing which
one is failing, fix that to help diagnosing problems, such as the
syscall tracepoints ones being found and fixes in this merge window.

Now the failing tests shows:

  # perf test -v "mmap interface"
 4: Read samples using the mmap interface                 :
  --- start ---
  test child forked, pid 14311
  
  perf_evsel__new(sys_enter_getppid)
  test child finished with -1
  ---- end ----
  Read samples using the mmap interface: FAILED!
  #

Now to check why the syscalls:sys_enter_getppid is failing...

  # ls -la /sys/kernel/debug/tracing/events/syscalls/sys_enter_getppid
  ls: cannot access '/sys/kernel/debug/tracing/events/syscalls/sys_enter_getppid': No such file or directory
  #

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Dominik Brodowski 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Steven Rostedt 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-44xk0ycdzrfzx1o9rklf5itl@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tests: Disable breakpoint accounting test for powerpc

2018-04-12T17:20:21+00:00

We disable this test as instruction breakpoints (HW_BREAKPOINT_X) are
not available for powerpc.

Before applying patch:

  21: Breakpoint accounting                                 :
  --- start ---
  test child forked, pid 3635
  failed opening event 0
  failed opening event 0
  watchpoints count 1, breakpoints count 0, has_ioctl 1, share 0
  test child finished with -2
  ---- end ----
  Breakpoint accounting: Skip

After applying patch:

  21: Breakpoint accounting                                 : Disabled

Signed-off-by: Sandipan Das 
Cc: Jiri Olsa 
Cc: Naveen N. Rao 
Cc: Ravi Bangoria 
Link: http://lkml.kernel.org/r/20180412162140.2992-1-sandipan@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

perf tests bpf: Remove unused ptrace.h include from LLVM test

2018-04-12T13:33:24+00:00

The bpf-script-test-kbuild.c script, used in one of the LLVM subtests,
includes ptrace.h unnecessarily, and that ends up making it include a
header that uses asm(_ASM_SP), a feature that is not supported by clang
<= 4.0, breaking that 'perf test' entry.

This ended up leading to the ca26cffa4e4a ("x86/asm: Allow again using
asm.h when building for the 'bpf' clang target"), adding an ifndef
__BPF__ to the arch/x86/include/asm/asm.h file.

Newer clang versions accept that asm(_ASM_SP) construct, so just remove
the ptrace.h include, which paves the way for reverting ca26cffa4e4a
("x86/asm: Allow again using asm.h when building for the 'bpf' clang
target").

Suggested-by: Yonghong Song 
Acked-by: Yonghong Song 
Link: https://lkml.kernel.org/r/613f0a0d-c433-8f4d-dcc1-c9889deae39e@fb.com
Cc: Adrian Hunter 
Cc: Alexander Potapenko 
Cc: Alexei Starovoitov 
Cc: Andrey Ryabinin 
Cc: Andy Lutomirski 
Cc: Arnd Bergmann 
Cc: Daniel Borkmann 
Cc: David Ahern 
Cc: Dmitriy Vyukov 
Cc: Jiri Olsa 
Cc: Josh Poimboeuf 
Cc: Linus Torvalds 
Cc: Matthias Kaehlcke 
Cc: Miguel Bernal Marin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: Wang Nan 
Link: https://lkml.kernel.org/n/tip-clbcnzbakdp18ibme4wt43ib@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tests bp_account: Fix build with clang-6

2018-03-19T16:51:54+00:00

To shut up this compiler warning:

    CC       /tmp/build/perf/tests/bp_account.o
    CC       /tmp/build/perf/tests/task-exit.o
    CC       /tmp/build/perf/tests/sw-clock.o
  tests/bp_account.c:106:20: error: pointer type mismatch ('int (*)(void)' and 'void *') [-Werror,-Wpointer-type-mismatch]
          void *addr = is_x ? test_function : (void *) &the_var;
                            ^ ~~~~~~~~~~~~~   ~~~~~~~~~~~~~~~~~
  1 error generated.

Noticed with clang 6 on fedora rawhide.

  [perfbuilder@44490f0e7241 perf]$ clang -v
  clang version 6.0.0 (tags/RELEASE_600/final)
  Target: x86_64-unknown-linux-gnu
  Thread model: posix
  InstalledDir: /usr/bin
  Found candidate GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/8
  Found candidate GCC installation: /usr/lib/gcc/x86_64-redhat-linux/8
  Selected GCC installation: /usr/bin/../lib/gcc/x86_64-redhat-linux/8
  Candidate multilib: .;@m64
  Candidate multilib: 32;@m32
  Selected multilib: .;@m64
  [perfbuilder@44490f0e7241 perf]$

Cc: Adrian Hunter 
Cc: David Ahern 
Cc: Jiri Olsa 
Cc: Namhyung Kim 
Cc: Wang Nan 
Fixes: 032db28e5fa3 ("perf tests: Add breakpoint accounting/modify test")
Link: https://lkml.kernel.org/n/tip-a3jnkzh4xam0l954de5tn66d@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo

perf tools: Fix snprint warnings for gcc 8

2018-03-19T13:00:43+00:00

With gcc 8 we get new set of snprintf() warnings that breaks the
compilation, one example:

  tests/mem.c: In function ‘check’:
  tests/mem.c:19:48: error: ‘%s’ directive output may be truncated writing \
        up to 99 bytes into a region of size 89 [-Werror=format-truncation=]
    snprintf(failure, sizeof failure, "unexpected %s", out);

The gcc docs says:

 To avoid the warning either use a bigger buffer or handle the
 function's return value which indicates whether or not its output
 has been truncated.

Given that all these warnings are harmless, because the code either
properly fails due to uncomplete file path or we don't care for
truncated output at all, I'm changing all those snprintf() calls to
scnprintf(), which actually 'checks' for the snprint return value so the
gcc stays silent.

Signed-off-by: Jiri Olsa 
Cc: Alexander Shishkin 
Cc: David Ahern 
Cc: Josh Poimboeuf 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Sergey Senozhatsky 
Link: http://lkml.kernel.org/r/20180319082902.4518-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo