linux/tools/perf/tests
Arnaldo Carvalho de Melo c369e0a1a8 perf tests bpf: Use SyS_epoll_wait alias
Something made the sys_epoll_wait() function alias not to be found in
the vmlinux DWARF info, being found only in /proc/kallsyms, which made
the BPF perf tests to fail:

  [root@jouet ~]# perf test BPF
  37: Test BPF filter                                          :
  37.1: Test basic BPF filtering                               : FAILED!
  37.2: Test BPF prologue generation                           : Skip
  37.3: Test BPF relocation checker                            : Skip
  [root@jouet ~]#

Using -v we can see it is failing to find DWARF info for the probed function,
sys_epoll_wait, which we can find in /proc/kallsyms but not in vmlinux with
CONFIG_DEBUG_INFO:

  [root@jouet ~]# grep -w sys_epoll_wait /proc/kallsyms
  ffffffffbd295b50 T sys_epoll_wait
  [root@jouet ~]#

  [root@jouet ~]# readelf -wi /lib/modules/4.7.0+/build/vmlinux | grep -w sys_epoll_wait
  [root@jouet ~]#

If we try to use perf probe:

[root@jouet ~]# perf probe sys_epoll_wait
Failed to find debug information for address ffffffffbd295b50
Probe point 'sys_epoll_wait' not found.
  Error: Failed to add events.
[root@jouet ~]#

It all works if we use SyS_epoll_wait, that is just an alias to the probed
function:

  [root@jouet ~]# grep -i sys_epoll_wait /proc/kallsyms
  ffffffffbd295b50 T SyS_epoll_wait
  ffffffffbd295b50 T sys_epoll_wait
  [root@jouet ~]#

So use it:

  [root@jouet ~]# perf test BPF
  37: Test BPF filter                                          :
  37.1: Test basic BPF filtering                               : Ok
  37.2: Test BPF prologue generation                           : Ok
  37.3: Test BPF relocation checker                            : Ok
  [root@jouet ~]#

Further info:

  [root@jouet ~]# gcc --version
  gcc (GCC) 6.1.1 20160621 (Red Hat 6.1.1-3)
  [acme@jouet linux]$ cat /etc/fedora-release
  Fedora release 24 (Twenty Four)

Investigation as to why it fails is still underway, but it was always
going from sys_epoll_wait to SyS_epoll_wait when looking up the DWARF
info in vmlinux, and this is what is breaking now.

Switching to use SyS_epoll_wait allows this test to proceed and test the
BPF code it was designed for, so lets have this in to allow passing this
test while we fix the root cause.

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-7hekjp0bodwjbb419sl2b55h@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-08-03 19:40:48 -03:00
..
attr perf tests: Fix attr tests 2015-04-08 10:49:53 -03:00
.gitignore perf test: Add libbpf relocation checker 2016-01-26 12:10:55 -03:00
Build perf tests: Add test for bitmap_scnprintf function 2016-08-02 16:33:27 -03:00
attr.c perf subcmd: Create subcmd library 2015-12-17 14:27:14 -03:00
attr.py perf tools: Remove EOL whitespaces 2015-01-21 13:24:31 -03:00
backward-ring-buffer.c perf tools: Enable overwrite settings 2016-07-15 17:27:51 -03:00
bitmap.c perf tests: Add test for bitmap_scnprintf function 2016-08-02 16:33:27 -03:00
bp_signal.c perf tests: Fix build on older systems where 'signal' is reserved 2016-02-15 17:33:26 -03:00
bp_signal_overflow.c perf tests: Pass the subtest index to each test routine 2015-11-19 13:19:15 -03:00
bpf-script-example.c perf tests bpf: Use SyS_epoll_wait alias 2016-08-03 19:40:48 -03:00
bpf-script-test-kbuild.c perf test: Enhance the LLVM tests: add kbuild test 2015-11-06 17:49:50 -03:00
bpf-script-test-prologue.c perf test: Test the BPF prologue adding infrastructure 2015-11-18 17:51:04 -03:00
bpf-script-test-relocation.c perf test: Add libbpf relocation checker 2016-01-26 12:10:55 -03:00
bpf.c perf test bpf: Use epoll_wait() instead of epoll_pwait() 2016-07-12 15:20:33 -03:00
builtin-test.c perf tests: Add test for bitmap_scnprintf function 2016-08-02 16:33:27 -03:00
code-reading.c perf tests: objdump output can contain multi byte chunks 2016-08-02 16:42:51 -03:00
cpumap.c perf tests cpumap: Add missing headers 2016-07-12 15:19:56 -03:00
dso-data.c perf tools: Allow to reset open files counter 2016-06-30 18:27:44 -03:00
dwarf-unwind.c perf tests: Forward the perf_sample in the dwarf unwind test 2016-03-23 12:03:07 -03:00
event-times.c tools: Introduce str_error_r() 2016-07-12 15:19:47 -03:00
event_update.c perf tests: Replace assignment with comparison on assert check 2016-04-25 20:24:26 -03:00
evsel-roundtrip-name.c perf evlist: Rename for_each() macros to for_each_entry() 2016-06-23 11:26:15 -03:00
evsel-tp-sched.c perf tests: Pass the subtest index to each test routine 2015-11-19 13:19:15 -03:00
fdarray.c perf test fdarray: Add missing poll.h header 2016-07-12 15:19:56 -03:00
hists_common.c perf hists: Move sort__need_collapse into struct perf_hpp_list 2016-05-05 21:03:58 -03:00
hists_common.h perf tests: Define and use symbolic names for fake symbols 2014-06-01 14:35:11 +02:00
hists_cumulate.c perf tests: Fix hist accumulation test 2016-07-04 19:39:01 -03:00
hists_filter.c perf evlist: Rename for_each() macros to for_each_entry() 2016-06-23 11:26:15 -03:00
hists_link.c perf evlist: Rename for_each() macros to for_each_entry() 2016-06-23 11:26:15 -03:00
hists_output.c perf hists: Move sort__need_collapse into struct perf_hpp_list 2016-05-05 21:03:58 -03:00
is_printable_array.c perf tests: Add is_printable_array test 2016-07-18 19:50:35 -03:00
keep-tracking.c perf evsel: Do not use globals in config() 2016-04-11 22:18:20 -03:00
kmod-path.c perf tests kmod-path: Fix build on ubuntu:16.04-x-armhf 2016-07-22 16:25:44 -03:00
llvm.c perf tools: Remove needless includes from cache.h 2016-07-12 15:19:58 -03:00
llvm.h perf test: Add libbpf relocation checker 2016-01-26 12:10:55 -03:00
make perf build: Add sdt feature detection 2016-07-13 23:09:09 -03:00
mmap-basic.c perf tests: Add missing pthread.h include for CPU_*() macros 2016-07-12 15:19:53 -03:00
mmap-thread-lookup.c perf test: Use machine__new_host in mmap thread lookup test 2015-12-07 18:12:54 -03:00
openat-syscall-all-cpus.c perf tests: Add missing pthread.h include for CPU_*() macros 2016-07-12 15:19:53 -03:00
openat-syscall-tp-fields.c perf tests openat-syscall-tp-fields: Add some conditional defines 2016-07-12 15:19:54 -03:00
openat-syscall.c tools: Introduce str_error_r() 2016-07-12 15:19:47 -03:00
parse-events.c perf evlist: Rename for_each() macros to for_each_entry() 2016-06-23 11:26:15 -03:00
parse-no-sample-id-all.c perf evlist: Destructors should accept NULL 2016-06-22 10:01:48 -03:00
perf-record.c perf tests: Add missing pthread.h include for CPU_*() macros 2016-07-12 15:19:53 -03:00
perf-targz-src-pkg perf tests: Fix tarpkg build test error output redirection 2016-03-24 12:26:41 -03:00
pmu.c perf tests: Pass the subtest index to each test routine 2015-11-19 13:19:15 -03:00
python-use.c perf tests: Pass the subtest index to each test routine 2015-11-19 13:19:15 -03:00
sample-parsing.c perf tests: Pass the subtest index to each test routine 2015-11-19 13:19:15 -03:00
sdt.c perf test: Add a test case for SDT event 2016-07-13 23:09:10 -03:00
stat.c perf tools: Add stat round event synthesize function 2015-12-17 14:55:44 -03:00
sw-clock.c tools: Introduce str_error_r() 2016-07-12 15:19:47 -03:00
switch-tracking.c perf evlist: Rename for_each() macros to for_each_entry() 2016-06-23 11:26:15 -03:00
task-exit.c tools: Introduce str_error_r() 2016-07-12 15:19:47 -03:00
tests.h perf tests: Add test for bitmap_scnprintf function 2016-08-02 16:33:27 -03:00
thread-map.c perf tests: Fix thread map test for -F option 2016-06-30 18:27:44 -03:00
thread-mg-share.c perf tests: Pass the subtest index to each test routine 2015-11-19 13:19:15 -03:00
topology.c perf tests: Pass the subtest index to each test routine 2015-11-19 13:19:15 -03:00
vmlinux-kallsyms.c perf test: Add missing verbose output explaining the reason for failure 2016-04-19 12:39:36 -03:00