From 3e96dac7c956089d3f23aca98c4dfca57b6aaf8a Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 11 Jan 2017 15:00:47 +0900 Subject: perf probe: Add error checks to offline probe post-processing Add error check codes on post processing and improve it for offline probe events as: - post processing fails if no matched symbol found in map(-ENOENT) or strdup() failed(-ENOMEM). - Even if the symbol name is the same, it updates symbol address and offset. Signed-off-by: Masami Hiramatsu Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/148411443738.9978.4617979132625405545.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 50 ++++++++++++++++++++++++++++--------------- 1 file changed, 33 insertions(+), 17 deletions(-) (limited to 'tools/perf/util/probe-event.c') diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 4a57c8a60bd9..aa8a9227080a 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -610,6 +610,33 @@ error: return ret ? : -ENOENT; } +/* Adjust symbol name and address */ +static int post_process_probe_trace_point(struct probe_trace_point *tp, + struct map *map, unsigned long offs) +{ + struct symbol *sym; + u64 addr = tp->address + tp->offset - offs; + + sym = map__find_symbol(map, addr); + if (!sym) + return -ENOENT; + + if (strcmp(sym->name, tp->symbol)) { + /* If we have no realname, use symbol for it */ + if (!tp->realname) + tp->realname = tp->symbol; + else + free(tp->symbol); + tp->symbol = strdup(sym->name); + if (!tp->symbol) + return -ENOMEM; + } + tp->offset = addr - sym->start; + tp->address -= offs; + + return 0; +} + /* * Rename DWARF symbols to ELF symbols -- gcc sometimes optimizes functions * and generate new symbols with suffixes such as .constprop.N or .isra.N @@ -622,11 +649,9 @@ static int post_process_offline_probe_trace_events(struct probe_trace_event *tevs, int ntevs, const char *pathname) { - struct symbol *sym; struct map *map; unsigned long stext = 0; - u64 addr; - int i; + int i, ret = 0; /* Prepare a map for offline binary */ map = dso__new_map(pathname); @@ -636,23 +661,14 @@ post_process_offline_probe_trace_events(struct probe_trace_event *tevs, } for (i = 0; i < ntevs; i++) { - addr = tevs[i].point.address + tevs[i].point.offset - stext; - sym = map__find_symbol(map, addr); - if (!sym) - continue; - if (!strcmp(sym->name, tevs[i].point.symbol)) - continue; - /* If we have no realname, use symbol for it */ - if (!tevs[i].point.realname) - tevs[i].point.realname = tevs[i].point.symbol; - else - free(tevs[i].point.symbol); - tevs[i].point.symbol = strdup(sym->name); - tevs[i].point.offset = addr - sym->start; + ret = post_process_probe_trace_point(&tevs[i].point, + map, stext); + if (ret < 0) + break; } map__put(map); - return 0; + return ret; } static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs, -- cgit From 613f050d68a8ed3c0b18b9568698908ef7bbc1f7 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 11 Jan 2017 15:01:57 +0900 Subject: perf probe: Fix to probe on gcc generated functions in modules Fix to probe on gcc generated functions on modules. Since probing on a module is based on its symbol name, it should be adjusted on actual symbols. E.g. without this fix, perf probe shows probe definition on non-exist symbol as below. $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -F in_range* in_range.isra.12 $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range p:probe/in_range nf_nat:in_range+0 With this fix, perf probe correctly shows a probe on gcc-generated symbol. $ perf probe -m build-x86_64/net/netfilter/nf_nat.ko -D in_range p:probe/in_range nf_nat:in_range.isra.12+0 This also fixes same problem on online module as below. $ perf probe -m i915 -D assert_plane p:probe/assert_plane i915:assert_plane.constprop.134+0 Signed-off-by: Masami Hiramatsu Tested-by: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/148411450673.9978.14905987549651656075.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 45 ++++++++++++++++++++++++++++--------------- 1 file changed, 29 insertions(+), 16 deletions(-) (limited to 'tools/perf/util/probe-event.c') diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index aa8a9227080a..6a6f44dd594b 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -698,18 +698,31 @@ static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs, return ret; } -static int add_module_to_probe_trace_events(struct probe_trace_event *tevs, - int ntevs, const char *module) +static int +post_process_module_probe_trace_events(struct probe_trace_event *tevs, + int ntevs, const char *module, + struct debuginfo *dinfo) { + Dwarf_Addr text_offs = 0; int i, ret = 0; char *mod_name = NULL; + struct map *map; if (!module) return 0; - mod_name = find_module_name(module); + map = get_target_map(module, false); + if (!map || debuginfo__get_text_offset(dinfo, &text_offs, true) < 0) { + pr_warning("Failed to get ELF symbols for %s\n", module); + return -EINVAL; + } + mod_name = find_module_name(module); for (i = 0; i < ntevs; i++) { + ret = post_process_probe_trace_point(&tevs[i].point, + map, (unsigned long)text_offs); + if (ret < 0) + break; tevs[i].point.module = strdup(mod_name ? mod_name : module); if (!tevs[i].point.module) { @@ -719,6 +732,8 @@ static int add_module_to_probe_trace_events(struct probe_trace_event *tevs, } free(mod_name); + map__put(map); + return ret; } @@ -776,7 +791,7 @@ arch__post_process_probe_trace_events(struct perf_probe_event *pev __maybe_unuse static int post_process_probe_trace_events(struct perf_probe_event *pev, struct probe_trace_event *tevs, int ntevs, const char *module, - bool uprobe) + bool uprobe, struct debuginfo *dinfo) { int ret; @@ -784,7 +799,8 @@ static int post_process_probe_trace_events(struct perf_probe_event *pev, ret = add_exec_to_probe_trace_events(tevs, ntevs, module); else if (module) /* Currently ref_reloc_sym based probe is not for drivers */ - ret = add_module_to_probe_trace_events(tevs, ntevs, module); + ret = post_process_module_probe_trace_events(tevs, ntevs, + module, dinfo); else ret = post_process_kernel_probe_trace_events(tevs, ntevs); @@ -828,30 +844,27 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, } } - debuginfo__delete(dinfo); - if (ntevs > 0) { /* Succeeded to find trace events */ pr_debug("Found %d probe_trace_events.\n", ntevs); ret = post_process_probe_trace_events(pev, *tevs, ntevs, - pev->target, pev->uprobes); + pev->target, pev->uprobes, dinfo); if (ret < 0 || ret == ntevs) { + pr_debug("Post processing failed or all events are skipped. (%d)\n", ret); clear_probe_trace_events(*tevs, ntevs); zfree(tevs); + ntevs = 0; } - if (ret != ntevs) - return ret < 0 ? ret : ntevs; - ntevs = 0; - /* Fall through */ } + debuginfo__delete(dinfo); + if (ntevs == 0) { /* No error but failed to find probe point. */ pr_warning("Probe point '%s' not found.\n", synthesize_perf_probe_point(&pev->point)); return -ENOENT; - } - /* Error path : ntevs < 0 */ - pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs); - if (ntevs < 0) { + } else if (ntevs < 0) { + /* Error path : ntevs < 0 */ + pr_debug("An error occurred in debuginfo analysis (%d).\n", ntevs); if (ntevs == -EBADF) pr_warning("Warning: No dwarf info found in the vmlinux - " "please rebuild kernel with CONFIG_DEBUG_INFO=y.\n"); -- cgit