From 5a6f63145491f905de1c5c6c46c5cd62c004d0d1 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 6 Feb 2014 05:32:23 +0000 Subject: [PATCH] perf probe: Show source-level or symbol-level info for uprobes Show source-level or symbol-level information for uprobe events. Without this change; # ./perf probe -l probe_perf:dso__load_vmlinux (on 0x000000000006d110 in /kbuild/ksrc/linux-3/tools/perf/perf) With this change; # ./perf probe -l probe_perf:dso__load_vmlinux (on dso__load_vmlinux@util/symbol.c in /kbuild/ksrc/linux-3/tools/perf/perf) Changes from v2: - Update according to previous patches. Changes from v1: - Rewrite the code based on new series. Signed-off-by: Masami Hiramatsu Cc: David Ahern Cc: "David A. Long" Cc: Ingo Molnar Cc: Namhyung Kim Cc: Oleg Nesterov Cc: Srikar Dronamraju Cc: Steven Rostedt Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20140206053223.29635.51280.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 227 +++++++++++++++++++++------------- 1 file changed, 144 insertions(+), 83 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index f86820c39ea4..3c35b7af2adb 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -249,34 +249,6 @@ static int convert_exec_to_group(const char *exec, char **result) return ret; } -static int convert_to_perf_probe_point(struct probe_trace_point *tp, - struct perf_probe_point *pp) -{ - struct symbol *sym; - struct map *map; - u64 addr = kernel_get_symbol_address_by_name(tp->symbol, true); - - if (addr) { - addr += tp->offset; - sym = __find_kernel_function(addr, &map); - if (!sym) - goto failed; - pp->function = strdup(sym->name); - pp->offset = addr - map->unmap_ip(map, sym->start); - } else { -failed: - pp->function = strdup(tp->symbol); - pp->offset = tp->offset; - } - - if (pp->function == NULL) - return -ENOMEM; - - pp->retprobe = tp->retprobe; - - return 0; -} - #ifdef HAVE_DWARF_SUPPORT /* Open new debuginfo of given module */ static struct debuginfo *open_debuginfo(const char *module) @@ -298,44 +270,6 @@ static struct debuginfo *open_debuginfo(const char *module) return debuginfo__new(path); } -/* - * Convert trace point to probe point with debuginfo - * Currently only handles kprobes. - */ -static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, - struct perf_probe_point *pp) -{ - u64 addr = 0; - int ret = -ENOENT; - struct debuginfo *dinfo; - - addr = kernel_get_symbol_address_by_name(tp->symbol, false); - if (addr) { - addr += tp->offset; - pr_debug("try to find %s+%ld@%" PRIx64 "\n", tp->symbol, - tp->offset, addr); - - dinfo = open_debuginfo(tp->module); - if (dinfo) { - ret = debuginfo__find_probe_point(dinfo, - (unsigned long)addr, pp); - debuginfo__delete(dinfo); - } else { - pr_debug("Failed to open debuginfo at 0x%" PRIx64 "\n", - addr); - ret = -ENOENT; - } - } - if (ret <= 0) { - pr_debug("Failed to find corresponding probes from " - "debuginfo. Use kprobe event information.\n"); - return convert_to_perf_probe_point(tp, pp); - } - pp->retprobe = tp->retprobe; - - return 0; -} - static int get_text_start_address(const char *exec, unsigned long *address) { Elf *elf; @@ -364,6 +298,57 @@ static int get_text_start_address(const char *exec, unsigned long *address) return ret; } +/* + * Convert trace point to probe point with debuginfo + */ +static int find_perf_probe_point_from_dwarf(struct probe_trace_point *tp, + struct perf_probe_point *pp, + bool is_kprobe) +{ + struct debuginfo *dinfo = NULL; + unsigned long stext = 0; + u64 addr = tp->address; + int ret = -ENOENT; + + /* convert the address to dwarf address */ + if (!is_kprobe) { + if (!addr) { + ret = -EINVAL; + goto error; + } + ret = get_text_start_address(tp->module, &stext); + if (ret < 0) + goto error; + addr += stext; + } else { + addr = kernel_get_symbol_address_by_name(tp->symbol, false); + if (addr == 0) + goto error; + addr += tp->offset; + } + + pr_debug("try to find information at %" PRIx64 " in %s\n", addr, + tp->module ? : "kernel"); + + dinfo = open_debuginfo(tp->module); + if (dinfo) { + ret = debuginfo__find_probe_point(dinfo, + (unsigned long)addr, pp); + debuginfo__delete(dinfo); + } else { + pr_debug("Failed to open debuginfo at 0x%" PRIx64 "\n", addr); + ret = -ENOENT; + } + + if (ret > 0) { + pp->retprobe = tp->retprobe; + return 0; + } +error: + pr_debug("Failed to find corresponding probes from debuginfo.\n"); + return ret ? : -ENOENT; +} + static int add_exec_to_probe_trace_events(struct probe_trace_event *tevs, int ntevs, const char *exec) { @@ -815,10 +800,12 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, #else /* !HAVE_DWARF_SUPPORT */ -static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, - struct perf_probe_point *pp) +static int +find_perf_probe_point_from_dwarf(struct probe_trace_point *tp __maybe_unused, + struct perf_probe_point *pp __maybe_unused, + bool is_kprobe __maybe_unused) { - return convert_to_perf_probe_point(tp, pp); + return -ENOSYS; } static int try_to_find_probe_trace_events(struct perf_probe_event *pev, @@ -1343,16 +1330,21 @@ static int parse_probe_trace_command(const char *cmd, } else p = argv[1]; fmt1_str = strtok_r(p, "+", &fmt); - tp->symbol = strdup(fmt1_str); - if (tp->symbol == NULL) { - ret = -ENOMEM; - goto out; + if (fmt1_str[0] == '0') /* only the address started with 0x */ + tp->address = strtoul(fmt1_str, NULL, 0); + else { + /* Only the symbol-based probe has offset */ + tp->symbol = strdup(fmt1_str); + if (tp->symbol == NULL) { + ret = -ENOMEM; + goto out; + } + fmt2_str = strtok_r(NULL, "", &fmt); + if (fmt2_str == NULL) + tp->offset = 0; + else + tp->offset = strtoul(fmt2_str, NULL, 10); } - fmt2_str = strtok_r(NULL, "", &fmt); - if (fmt2_str == NULL) - tp->offset = 0; - else - tp->offset = strtoul(fmt2_str, NULL, 10); tev->nargs = argc - 2; tev->args = zalloc(sizeof(struct probe_trace_arg) * tev->nargs); @@ -1623,6 +1615,79 @@ char *synthesize_probe_trace_command(struct probe_trace_event *tev) return NULL; } +static int find_perf_probe_point_from_map(struct probe_trace_point *tp, + struct perf_probe_point *pp, + bool is_kprobe) +{ + struct symbol *sym = NULL; + struct map *map; + u64 addr; + int ret = -ENOENT; + + if (!is_kprobe) { + map = dso__new_map(tp->module); + if (!map) + goto out; + addr = tp->address; + sym = map__find_symbol(map, addr, NULL); + } else { + addr = kernel_get_symbol_address_by_name(tp->symbol, true); + if (addr) { + addr += tp->offset; + sym = __find_kernel_function(addr, &map); + } + } + if (!sym) + goto out; + + pp->retprobe = tp->retprobe; + pp->offset = addr - map->unmap_ip(map, sym->start); + pp->function = strdup(sym->name); + ret = pp->function ? 0 : -ENOMEM; + +out: + if (map && !is_kprobe) { + dso__delete(map->dso); + map__delete(map); + } + + return ret; +} + +static int convert_to_perf_probe_point(struct probe_trace_point *tp, + struct perf_probe_point *pp, + bool is_kprobe) +{ + char buf[128]; + int ret; + + ret = find_perf_probe_point_from_dwarf(tp, pp, is_kprobe); + if (!ret) + return 0; + ret = find_perf_probe_point_from_map(tp, pp, is_kprobe); + if (!ret) + return 0; + + pr_debug("Failed to find probe point from both of dwarf and map.\n"); + + if (tp->symbol) { + pp->function = strdup(tp->symbol); + pp->offset = tp->offset; + } else if (!tp->module && !is_kprobe) { + ret = e_snprintf(buf, 128, "0x%" PRIx64, (u64)tp->address); + if (ret < 0) + return ret; + pp->function = strdup(buf); + pp->offset = 0; + } + if (pp->function == NULL) + return -ENOMEM; + + pp->retprobe = tp->retprobe; + + return 0; +} + static int convert_to_perf_probe_event(struct probe_trace_event *tev, struct perf_probe_event *pev, bool is_kprobe) { @@ -1636,11 +1701,7 @@ static int convert_to_perf_probe_event(struct probe_trace_event *tev, return -ENOMEM; /* Convert trace_point to probe_point */ - if (is_kprobe) - ret = kprobe_convert_to_perf_probe(&tev->point, &pev->point); - else - ret = convert_to_perf_probe_point(&tev->point, &pev->point); - + ret = convert_to_perf_probe_point(&tev->point, &pev->point, is_kprobe); if (ret < 0) return ret; -- GitLab