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H A Dsymbol-elf.c59a17706 Mon Jan 28 07:35:26 CST 2019 Jiri Olsa <jolsa@redhat.com> perf symbols: Filter out hidden symbols from labels

When perf is built with the annobin plugin (RHEL8 build) extra symbols
are added to its binary:

# nm perf | grep annobin | head -10
0000000000241100 t .annobin_annotate.c
0000000000326490 t .annobin_annotate.c
0000000000249255 t .annobin_annotate.c_end
00000000003283a8 t .annobin_annotate.c_end
00000000001bce18 t .annobin_annotate.c_end.hot
00000000001bce18 t .annobin_annotate.c_end.hot
00000000001bc3e2 t .annobin_annotate.c_end.unlikely
00000000001bc400 t .annobin_annotate.c_end.unlikely
00000000001bce18 t .annobin_annotate.c.hot
00000000001bce18 t .annobin_annotate.c.hot
...

Those symbols have no use for report or annotation and should be
skipped. Moreover they interfere with the DWARF unwind test on the PPC
arch, where they are mixed with checked symbols and then the test fails:

# perf test dwarf -v
59: Test dwarf unwind :
--- start ---
test child forked, pid 8515
unwind: .annobin_dwarf_unwind.c:ip = 0x10dba40dc (0x2740dc)
...
got: .annobin_dwarf_unwind.c 0x10dba40dc, expecting test__arch_unwind_sample
unwind: failed with 'no error'

The annobin symbols are defined as NOTYPE/LOCAL/HIDDEN:

# readelf -s ./perf | grep annobin | head -1
40: 00000000001bce4f 0 NOTYPE LOCAL HIDDEN 13 .annobin_init.c

They can still pass the check for the label symbol. Adding check for
HIDDEN and INTERNAL (as suggested by Nick below) visibility and filter
out such symbols.

> Just to be awkward, if you are going to ignore STV_HIDDEN
> symbols then you should probably also ignore STV_INTERNAL ones
> as well... Annobin does not generate them, but you never know,
> one day some other tool might create some.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Clifton <nickc@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190128133526.GD15461@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
59a17706 Mon Jan 28 07:35:26 CST 2019 Jiri Olsa <jolsa@redhat.com> perf symbols: Filter out hidden symbols from labels

When perf is built with the annobin plugin (RHEL8 build) extra symbols
are added to its binary:

# nm perf | grep annobin | head -10
0000000000241100 t .annobin_annotate.c
0000000000326490 t .annobin_annotate.c
0000000000249255 t .annobin_annotate.c_end
00000000003283a8 t .annobin_annotate.c_end
00000000001bce18 t .annobin_annotate.c_end.hot
00000000001bce18 t .annobin_annotate.c_end.hot
00000000001bc3e2 t .annobin_annotate.c_end.unlikely
00000000001bc400 t .annobin_annotate.c_end.unlikely
00000000001bce18 t .annobin_annotate.c.hot
00000000001bce18 t .annobin_annotate.c.hot
...

Those symbols have no use for report or annotation and should be
skipped. Moreover they interfere with the DWARF unwind test on the PPC
arch, where they are mixed with checked symbols and then the test fails:

# perf test dwarf -v
59: Test dwarf unwind :
--- start ---
test child forked, pid 8515
unwind: .annobin_dwarf_unwind.c:ip = 0x10dba40dc (0x2740dc)
...
got: .annobin_dwarf_unwind.c 0x10dba40dc, expecting test__arch_unwind_sample
unwind: failed with 'no error'

The annobin symbols are defined as NOTYPE/LOCAL/HIDDEN:

# readelf -s ./perf | grep annobin | head -1
40: 00000000001bce4f 0 NOTYPE LOCAL HIDDEN 13 .annobin_init.c

They can still pass the check for the label symbol. Adding check for
HIDDEN and INTERNAL (as suggested by Nick below) visibility and filter
out such symbols.

> Just to be awkward, if you are going to ignore STV_HIDDEN
> symbols then you should probably also ignore STV_INTERNAL ones
> as well... Annobin does not generate them, but you never know,
> one day some other tool might create some.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Nick Clifton <nickc@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20190128133526.GD15461@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>