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author | Ravi Bangoria <ravi.bangoria@linux.ibm.com> | 2018-08-20 10:12:50 +0530 |
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committer | Steven Rostedt (VMware) <rostedt@goodmis.org> | 2018-09-24 04:44:54 -0400 |
commit | 5a5e3d3ceae2121590d67258a4e658d938b4a46d (patch) | |
tree | 8aaaa9e1c859d86f0809454659dc5eaa68c13ebf | |
parent | ccea8727dc27d8f46df6557f9260ab32760ef409 (diff) | |
download | linux-5a5e3d3ceae2121590d67258a4e658d938b4a46d.tar.gz linux-5a5e3d3ceae2121590d67258a4e658d938b4a46d.tar.bz2 linux-5a5e3d3ceae2121590d67258a4e658d938b4a46d.zip |
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>
-rw-r--r-- | tools/perf/util/probe-event.c | 39 | ||||
-rw-r--r-- | tools/perf/util/probe-event.h | 1 | ||||
-rw-r--r-- | tools/perf/util/probe-file.c | 34 | ||||
-rw-r--r-- | tools/perf/util/probe-file.h | 1 | ||||
-rw-r--r-- | tools/perf/util/symbol-elf.c | 46 | ||||
-rw-r--r-- | tools/perf/util/symbol.h | 7 |
6 files changed, 106 insertions, 22 deletions
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index f119eb628dbb..e86f8be89157 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -1819,6 +1819,12 @@ int parse_probe_trace_command(const char *cmd, struct probe_trace_event *tev) tp->offset = strtoul(fmt2_str, NULL, 10); } + if (tev->uprobes) { + fmt2_str = strchr(p, '('); + if (fmt2_str) + tp->ref_ctr_offset = strtoul(fmt2_str + 1, NULL, 0); + } + tev->nargs = argc - 2; tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); if (tev->args == NULL) { @@ -2012,6 +2018,22 @@ static int synthesize_probe_trace_arg(struct probe_trace_arg *arg, return err; } +static int +synthesize_uprobe_trace_def(struct probe_trace_event *tev, struct strbuf *buf) +{ + struct probe_trace_point *tp = &tev->point; + int err; + + err = strbuf_addf(buf, "%s:0x%lx", tp->module, tp->address); + + if (err >= 0 && tp->ref_ctr_offset) { + if (!uprobe_ref_ctr_is_supported()) + return -1; + err = strbuf_addf(buf, "(0x%lx)", tp->ref_ctr_offset); + } + return err >= 0 ? 0 : -1; +} + char *synthesize_probe_trace_command(struct probe_trace_event *tev) { struct probe_trace_point *tp = &tev->point; @@ -2041,15 +2063,17 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev) } /* Use the tp->address for uprobes */ - if (tev->uprobes) - err = strbuf_addf(&buf, "%s:0x%lx", tp->module, tp->address); - else if (!strncmp(tp->symbol, "0x", 2)) + if (tev->uprobes) { + err = synthesize_uprobe_trace_def(tev, &buf); + } else if (!strncmp(tp->symbol, "0x", 2)) { /* Absolute address. See try_to_find_absolute_address() */ err = strbuf_addf(&buf, "%s%s0x%lx", tp->module ?: "", tp->module ? ":" : "", tp->address); - else + } else { err = strbuf_addf(&buf, "%s%s%s+%lu", tp->module ?: "", tp->module ? ":" : "", tp->symbol, tp->offset); + } + if (err) goto error; @@ -2633,6 +2657,13 @@ static void warn_uprobe_event_compat(struct probe_trace_event *tev) { int i; char *buf = synthesize_probe_trace_command(tev); + struct probe_trace_point *tp = &tev->point; + + if (tp->ref_ctr_offset && !uprobe_ref_ctr_is_supported()) { + pr_warning("A semaphore is associated with %s:%s and " + "seems your kernel doesn't support it.\n", + tev->group, tev->event); + } /* Old uprobe event doesn't support memory dereference */ if (!tev->uprobes || tev->nargs == 0 || !buf) diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index 45b14f020558..15a98c3a2a2f 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -27,6 +27,7 @@ struct probe_trace_point { char *symbol; /* Base symbol */ char *module; /* Module name */ unsigned long offset; /* Offset from symbol */ + unsigned long ref_ctr_offset; /* SDT reference counter offset */ unsigned long address; /* Actual address of the trace point */ bool retprobe; /* Return probe flag */ }; diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c index b76088fadf3d..aac7817d9e14 100644 --- a/tools/perf/util/probe-file.c +++ b/tools/perf/util/probe-file.c @@ -696,8 +696,16 @@ out_err: #ifdef HAVE_GELF_GETNOTE_SUPPORT static unsigned long long sdt_note__get_addr(struct sdt_note *note) { - return note->bit32 ? (unsigned long long)note->addr.a32[0] - : (unsigned long long)note->addr.a64[0]; + return note->bit32 ? + (unsigned long long)note->addr.a32[SDT_NOTE_IDX_LOC] : + (unsigned long long)note->addr.a64[SDT_NOTE_IDX_LOC]; +} + +static unsigned long long sdt_note__get_ref_ctr_offset(struct sdt_note *note) +{ + return note->bit32 ? + (unsigned long long)note->addr.a32[SDT_NOTE_IDX_REFCTR] : + (unsigned long long)note->addr.a64[SDT_NOTE_IDX_REFCTR]; } static const char * const type_to_suffix[] = { @@ -775,14 +783,21 @@ static char *synthesize_sdt_probe_command(struct sdt_note *note, { struct strbuf buf; char *ret = NULL, **args; - int i, args_count; + int i, args_count, err; + unsigned long long ref_ctr_offset; if (strbuf_init(&buf, 32) < 0) return NULL; - if (strbuf_addf(&buf, "p:%s/%s %s:0x%llx", - sdtgrp, note->name, pathname, - sdt_note__get_addr(note)) < 0) + err = strbuf_addf(&buf, "p:%s/%s %s:0x%llx", + sdtgrp, note->name, pathname, + sdt_note__get_addr(note)); + + ref_ctr_offset = sdt_note__get_ref_ctr_offset(note); + if (ref_ctr_offset && err >= 0) + err = strbuf_addf(&buf, "(0x%llx)", ref_ctr_offset); + + if (err < 0) goto error; if (!note->args) @@ -998,6 +1013,7 @@ int probe_cache__show_all_caches(struct strfilter *filter) enum ftrace_readme { FTRACE_README_PROBE_TYPE_X = 0, FTRACE_README_KRETPROBE_OFFSET, + FTRACE_README_UPROBE_REF_CTR, FTRACE_README_END, }; @@ -1009,6 +1025,7 @@ static struct { [idx] = {.pattern = pat, .avail = false} DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"), DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"), + DEFINE_TYPE(FTRACE_README_UPROBE_REF_CTR, "*ref_ctr_offset*"), }; static bool scan_ftrace_readme(enum ftrace_readme type) @@ -1064,3 +1081,8 @@ bool kretprobe_offset_is_supported(void) { return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET); } + +bool uprobe_ref_ctr_is_supported(void) +{ + return scan_ftrace_readme(FTRACE_README_UPROBE_REF_CTR); +} diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h index 63f29b1d22c1..2a249182f2a6 100644 --- a/tools/perf/util/probe-file.h +++ b/tools/perf/util/probe-file.h @@ -69,6 +69,7 @@ struct probe_cache_entry *probe_cache__find_by_name(struct probe_cache *pcache, int probe_cache__show_all_caches(struct strfilter *filter); bool probe_type_is_available(enum probe_type type); bool kretprobe_offset_is_supported(void); +bool uprobe_ref_ctr_is_supported(void); #else /* ! HAVE_LIBELF_SUPPORT */ static inline struct probe_cache *probe_cache__new(const char *tgt __maybe_unused, struct nsinfo *nsi __maybe_unused) { 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; diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h index f25fae4b5743..20f49779116b 100644 --- a/tools/perf/util/symbol.h +++ b/tools/perf/util/symbol.h @@ -379,12 +379,19 @@ int get_sdt_note_list(struct list_head *head, const char *target); int cleanup_sdt_note_list(struct list_head *sdt_notes); int sdt_notes__get_count(struct list_head *start); +#define SDT_PROBES_SCN ".probes" #define SDT_BASE_SCN ".stapsdt.base" #define SDT_NOTE_SCN ".note.stapsdt" #define SDT_NOTE_TYPE 3 #define SDT_NOTE_NAME "stapsdt" #define NR_ADDR 3 +enum { + SDT_NOTE_IDX_LOC = 0, + SDT_NOTE_IDX_BASE, + SDT_NOTE_IDX_REFCTR, +}; + struct mem_info *mem_info__new(void); struct mem_info *mem_info__get(struct mem_info *mi); void mem_info__put(struct mem_info *mi); |