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| author | Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2018-08-20 10:12:50 +0530 |
|---|---|---|
| committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-09-24 04:44:54 -0400 |
| commit | 5a5e3d3ceae2121590d67258a4e658d938b4a46d (patch) | |
| tree | 8aaaa9e1c859d86f0809454659dc5eaa68c13ebf /tools/perf/util/symbol-elf.c | |
| parent | ccea8727dc27d8f46df6557f9260ab32760ef409 (diff) | |
| download | linux-5a5e3d3ceae2121590d67258a4e658d938b4a46d.tar.bz2 | |
perf probe: Support SDT markers having reference counter (semaphore)
With this, perf buildid-cache will save SDT markers with reference
counter in probe cache. Perf probe will be able to probe markers
having reference counter. Ex,
# readelf -n /tmp/tick | grep -A1 loop2
Name: loop2
... Semaphore: 0x0000000010020036
# ./perf buildid-cache --add /tmp/tick
# ./perf probe sdt_tick:loop2
# ./perf stat -e sdt_tick:loop2 /tmp/tick
hi: 0
hi: 1
hi: 2
^C
Performance counter stats for '/tmp/tick':
3 sdt_tick:loop2
2.561851452 seconds time elapsed
Link: http://lkml.kernel.org/r/20180820044250.11659-5-ravi.bangoria@linux.ibm.com
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Reviewed-by: Song Liu <songliubraving@fb.com>
Tested-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Diffstat (limited to 'tools/perf/util/symbol-elf.c')
| -rw-r--r-- | tools/perf/util/symbol-elf.c | 46 |
1 files changed, 34 insertions, 12 deletions
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c index 29770ea61768..0281d5e2cd67 100644 --- a/tools/perf/util/symbol-elf.c +++ b/tools/perf/util/symbol-elf.c @@ -1947,6 +1947,34 @@ void kcore_extract__delete(struct kcore_extract *kce) } #ifdef HAVE_GELF_GETNOTE_SUPPORT + +static void sdt_adjust_loc(struct sdt_note *tmp, GElf_Addr base_off) +{ + if (!base_off) + return; + + if (tmp->bit32) + tmp->addr.a32[SDT_NOTE_IDX_LOC] = + tmp->addr.a32[SDT_NOTE_IDX_LOC] + base_off - + tmp->addr.a32[SDT_NOTE_IDX_BASE]; + else + tmp->addr.a64[SDT_NOTE_IDX_LOC] = + tmp->addr.a64[SDT_NOTE_IDX_LOC] + base_off - + tmp->addr.a64[SDT_NOTE_IDX_BASE]; +} + +static void sdt_adjust_refctr(struct sdt_note *tmp, GElf_Addr base_addr, + GElf_Addr base_off) +{ + if (!base_off) + return; + + if (tmp->bit32 && tmp->addr.a32[SDT_NOTE_IDX_REFCTR]) + tmp->addr.a32[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off); + else if (tmp->addr.a64[SDT_NOTE_IDX_REFCTR]) + tmp->addr.a64[SDT_NOTE_IDX_REFCTR] -= (base_addr - base_off); +} + /** * populate_sdt_note : Parse raw data and identify SDT note * @elf: elf of the opened file @@ -1964,7 +1992,6 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len, const char *provider, *name, *args; struct sdt_note *tmp = NULL; GElf_Ehdr ehdr; - GElf_Addr base_off = 0; GElf_Shdr shdr; int ret = -EINVAL; @@ -2060,17 +2087,12 @@ static int populate_sdt_note(Elf **elf, const char *data, size_t len, * base address in the description of the SDT note. If its different, * then accordingly, adjust the note location. */ - if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) { - base_off = shdr.sh_offset; - if (base_off) { - if (tmp->bit32) - tmp->addr.a32[0] = tmp->addr.a32[0] + base_off - - tmp->addr.a32[1]; - else - tmp->addr.a64[0] = tmp->addr.a64[0] + base_off - - tmp->addr.a64[1]; - } - } + if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_BASE_SCN, NULL)) + sdt_adjust_loc(tmp, shdr.sh_offset); + + /* Adjust reference counter offset */ + if (elf_section_by_name(*elf, &ehdr, &shdr, SDT_PROBES_SCN, NULL)) + sdt_adjust_refctr(tmp, shdr.sh_addr, shdr.sh_offset); list_add_tail(&tmp->note_list, sdt_notes); return 0; |