From 6430a94ead2a4c8f350441351a735303eb6d1c8a Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Fri, 1 Jul 2016 17:04:10 +0900 Subject: [PATCH] perf buildid-cache: Scan and import user SDT events to probe cache perf buildid-cache --add scans given binary and add the SDT events to probe cache. "sdt_" prefix is appended for all SDT providers to avoid event-name clash with other pre-defined events. It is possible to use the cached SDT events as other cached events, via perf probe --add "sdt_:=". e.g. ---- # perf buildid-cache --add /lib/libc-2.17.so # perf probe --cache --list | head -n 5 /usr/lib/libc-2.17.so (a6fb821bdf53660eb2c29f778757aef294d3d392): sdt_libc:setjmp=setjmp sdt_libc:longjmp=longjmp sdt_libc:longjmp_target=longjmp_target sdt_libc:memory_heap_new=memory_heap_new # perf probe -x /usr/lib/libc-2.17.so \ -a sdt_libc:memory_heap_new=memory_heap_new Added new event: sdt_libc:memory_heap_new (on memory_heap_new in /usr/lib/libc-2.17.so) You can now use it in all perf tools, such as: perf record -e sdt_libc:memory_heap_new -aR sleep 1 # perf probe -l sdt_libc:memory_heap_new (on new_heap+183 in /usr/lib/libc-2.17.so) ---- Note that SDT event entries in probe-cache file is somewhat different from normal cached events. Normal one starts with "#", but SDTs are starting with "%". Signed-off-by: Masami Hiramatsu Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Brendan Gregg Cc: Hemant Kumar Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/146736025058.27797.13043265488541434502.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo --- .../perf/Documentation/perf-buildid-cache.txt | 3 + tools/perf/util/build-id.c | 30 ++++++++ tools/perf/util/probe-file.c | 69 ++++++++++++++++++- tools/perf/util/probe-file.h | 2 + 4 files changed, 101 insertions(+), 3 deletions(-) diff --git a/tools/perf/Documentation/perf-buildid-cache.txt b/tools/perf/Documentation/perf-buildid-cache.txt index dd07b55f58d8..058064db39d2 100644 --- a/tools/perf/Documentation/perf-buildid-cache.txt +++ b/tools/perf/Documentation/perf-buildid-cache.txt @@ -15,6 +15,9 @@ DESCRIPTION This command manages the build-id cache. It can add, remove, update and purge files to/from the cache. In the future it should as well set upper limits for the space used by the cache, etc. +This also scans the target binary for SDT (Statically Defined Tracing) and +record it along with the buildid-cache, which will be used by perf-probe. +For more details, see linkperf:perf-probe[1]. OPTIONS ------- diff --git a/tools/perf/util/build-id.c b/tools/perf/util/build-id.c index 1c49620e98b2..e1a16408da9c 100644 --- a/tools/perf/util/build-id.c +++ b/tools/perf/util/build-id.c @@ -17,6 +17,7 @@ #include "tool.h" #include "header.h" #include "vdso.h" +#include "probe-file.h" static bool no_buildid_cache; @@ -532,6 +533,30 @@ int build_id_cache__list_build_ids(const char *pathname, return ret; } +#ifdef HAVE_LIBELF_SUPPORT +static int build_id_cache__add_sdt_cache(const char *sbuild_id, + const char *realname) +{ + struct probe_cache *cache; + int ret; + + cache = probe_cache__new(sbuild_id); + if (!cache) + return -1; + + ret = probe_cache__scan_sdt(cache, realname); + if (ret >= 0) { + pr_debug("Found %d SDTs in %s\n", ret, realname); + if (probe_cache__commit(cache) < 0) + ret = -1; + } + probe_cache__delete(cache); + return ret; +} +#else +#define build_id_cache__add_sdt_cache(sbuild_id, realname) (0) +#endif + int build_id_cache__add_s(const char *sbuild_id, const char *name, bool is_kallsyms, bool is_vdso) { @@ -589,6 +614,11 @@ int build_id_cache__add_s(const char *sbuild_id, const char *name, if (symlink(tmp, linkname) == 0) err = 0; + + /* Update SDT cache : error is just warned */ + if (build_id_cache__add_sdt_cache(sbuild_id, realname) < 0) + pr_debug("Failed to update/scan SDT cache for %s\n", realname); + out_free: if (!is_kallsyms) free(realname); diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c index 6cb6ec03c1fe..5b563b2e8b1d 100644 --- a/tools/perf/util/probe-file.c +++ b/tools/perf/util/probe-file.c @@ -434,12 +434,15 @@ static int probe_cache__load(struct probe_cache *pcache) p = strchr(buf, '\n'); if (p) *p = '\0'; - if (buf[0] == '#') { /* #perf_probe_event */ + /* #perf_probe_event or %sdt_event */ + if (buf[0] == '#' || buf[0] == '%') { entry = probe_cache_entry__new(NULL); if (!entry) { ret = -ENOMEM; goto out; } + if (buf[0] == '%') + entry->sdt = true; entry->spev = strdup(buf + 1); if (entry->spev) ret = parse_perf_probe_command(buf + 1, @@ -621,19 +624,79 @@ int probe_cache__add_entry(struct probe_cache *pcache, return ret; } +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]; +} + +int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname) +{ + struct probe_cache_entry *entry = NULL; + struct list_head sdtlist; + struct sdt_note *note; + char *buf; + char sdtgrp[64]; + int ret; + + INIT_LIST_HEAD(&sdtlist); + ret = get_sdt_note_list(&sdtlist, pathname); + if (ret < 0) { + pr_debug("Failed to get sdt note: %d\n", ret); + return ret; + } + list_for_each_entry(note, &sdtlist, note_list) { + ret = snprintf(sdtgrp, 64, "sdt_%s", note->provider); + if (ret < 0) + break; + /* Try to find same-name entry */ + entry = probe_cache__find_by_name(pcache, sdtgrp, note->name); + if (!entry) { + entry = probe_cache_entry__new(NULL); + if (!entry) { + ret = -ENOMEM; + break; + } + entry->sdt = true; + ret = asprintf(&entry->spev, "%s:%s=%s", sdtgrp, + note->name, note->name); + if (ret < 0) + break; + entry->pev.event = strdup(note->name); + entry->pev.group = strdup(sdtgrp); + list_add_tail(&entry->node, &pcache->entries); + } + ret = asprintf(&buf, "p:%s/%s %s:0x%llx", + sdtgrp, note->name, pathname, + sdt_note__get_addr(note)); + if (ret < 0) + break; + strlist__add(entry->tevlist, buf); + free(buf); + entry = NULL; + } + if (entry) { + list_del_init(&entry->node); + probe_cache_entry__delete(entry); + } + cleanup_sdt_note_list(&sdtlist); + return ret; +} + static int probe_cache_entry__write(struct probe_cache_entry *entry, int fd) { struct str_node *snode; struct stat st; struct iovec iov[3]; + const char *prefix = entry->sdt ? "%" : "#"; int ret; /* Save stat for rollback */ ret = fstat(fd, &st); if (ret < 0) return ret; - pr_debug("Writing cache: #%s\n", entry->spev); - iov[0].iov_base = (void *)"#"; iov[0].iov_len = 1; + pr_debug("Writing cache: %s%s\n", prefix, entry->spev); + iov[0].iov_base = (void *)prefix; iov[0].iov_len = 1; iov[1].iov_base = entry->spev; iov[1].iov_len = strlen(entry->spev); iov[2].iov_base = (void *)"\n"; iov[2].iov_len = 1; ret = writev(fd, iov, 3); diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h index 0ed1fc563b77..ddf5ae212c2f 100644 --- a/tools/perf/util/probe-file.h +++ b/tools/perf/util/probe-file.h @@ -8,6 +8,7 @@ /* Cache of probe definitions */ struct probe_cache_entry { struct list_head node; + bool sdt; struct perf_probe_event pev; char *spev; struct strlist *tevlist; @@ -35,6 +36,7 @@ struct probe_cache *probe_cache__new(const char *target); int probe_cache__add_entry(struct probe_cache *pcache, struct perf_probe_event *pev, struct probe_trace_event *tevs, int ntevs); +int probe_cache__scan_sdt(struct probe_cache *pcache, const char *pathname); int probe_cache__commit(struct probe_cache *pcache); void probe_cache__purge(struct probe_cache *pcache); void probe_cache__delete(struct probe_cache *pcache); -- GitLab