Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756174AbaAWCbQ (ORCPT ); Wed, 22 Jan 2014 21:31:16 -0500 Received: from mail7.hitachi.co.jp ([133.145.228.42]:51880 "EHLO mail7.hitachi.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755868AbaAWCaA (ORCPT ); Wed, 22 Jan 2014 21:30:00 -0500 Subject: [PATCH -tip 5/8] perf-probe: Show source level information for address only kprobes To: Arnaldo Carvalho de Melo From: Masami Hiramatsu Cc: Srikar Dronamraju , David Ahern , linux-kernel@vger.kernel.org, "Steven Rostedt (Red Hat)" , Oleg Nesterov , Ingo Molnar , "David A. Long" , yrl.pp-manager.tt@hitachi.com, Namhyung Kim Date: Thu, 23 Jan 2014 02:29:57 +0000 Message-ID: <20140123022957.7206.56546.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp> In-Reply-To: <20140123022945.7206.79944.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp> References: <20140123022945.7206.79944.stgit@kbuild-fedora.yrl.intra.hitachi.co.jp> User-Agent: StGit/0.16 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Show the source code level information for address only kprobe events. Currently the perf probe shows such information only for symbol-based probes. With this change, perf-probe correctly parses the address-based events and tries to find the actual lines of code from the debuginfo. E.g. without this patch; # ./perf probe -l probe:t_show (on 0xffffffff810d9720 with m v) probe:t_show_1 (on 0xffffffff810e2e40 with m v t) probe:t_show_2 (on 0xffffffff810ece30 with m v fmt) probe:t_show_3 (on 0xffffffff810f4ad0 with m v file) With this patch; # ./perf probe -l probe:t_show (on t_show@linux-3/kernel/trace/ftrace.c with m v) probe:t_show_1 (on t_show@linux-3/kernel/trace/trace.c with m v t) probe:t_show_2 (on t_show@kernel/trace/trace_printk.c with m v fmt) probe:t_show_3 (on t_show@kernel/trace/trace_events.c with m v file) Signed-off-by: Masami Hiramatsu --- tools/perf/util/probe-event.c | 87 ++++++++++++++++++++++++++--------------- 1 file changed, 56 insertions(+), 31 deletions(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 92ab688..3470934 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -153,7 +153,7 @@ static struct dso *kernel_get_module_dso(const char *module) struct map *map; const char *vmlinux_name; - if (module) { + if (module && strcmp(module, "kernel") != 0) { list_for_each_entry(dso, &host_machine->kernel_dsos, node) { if (strncmp(dso->short_name + 1, module, dso->short_name_len - 2) == 0) @@ -220,12 +220,22 @@ out: static int convert_to_perf_probe_point(struct probe_trace_point *tp, struct perf_probe_point *pp) { - pp->function = strdup(tp->symbol); + char buf[128]; + int ret; + if (tp->symbol) { + pp->function = strdup(tp->symbol); + pp->offset = tp->offset; + } else { + 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->offset = tp->offset; pp->retprobe = tp->retprobe; return 0; @@ -261,28 +271,35 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, { struct symbol *sym; struct map *map; - u64 addr; - int ret = -ENOENT; + u64 addr = tp->address; + int ret; struct debuginfo *dinfo; - sym = __find_kernel_function_by_name(tp->symbol, &map); - if (sym) { + if (!addr) { + sym = __find_kernel_function_by_name(tp->symbol, &map); + if (!sym) { + ret = -ENOENT; + goto error; + } addr = map->unmap_ip(map, sym->start + tp->offset); - pr_debug("try to find %s+%ld@%" PRIx64 "\n", tp->symbol, - tp->offset, addr); + } + + pr_debug("try to find information at %" PRIx64 " in %s\n", addr, + tp->module ? : "kernel"); - dinfo = debuginfo__new_online_kernel(addr); - if (dinfo) { - ret = debuginfo__find_probe_point(dinfo, + dinfo = debuginfo__new_online_kernel(addr); + 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; - } + debuginfo__delete(dinfo); + } else { + pr_debug("Failed to open debuginfo at 0x%" PRIx64 "\n", + addr); + ret = -ENOENT; } + if (ret <= 0) { +error: pr_debug("Failed to find corresponding probes from " "debuginfo. Use kprobe event information.\n"); return convert_to_perf_probe_point(tp, pp); @@ -745,10 +762,13 @@ static int kprobe_convert_to_perf_probe(struct probe_trace_point *tp, { struct symbol *sym; - sym = __find_kernel_function_by_name(tp->symbol, NULL); - if (!sym) { - pr_err("Failed to find symbol %s in kernel.\n", tp->symbol); - return -ENOENT; + if (tp->symbol) { + sym = __find_kernel_function_by_name(tp->symbol, NULL); + if (!sym) { + pr_err("Failed to find symbol %s in kernel.\n", + tp->symbol); + return -ENOENT; + } } return convert_to_perf_probe_point(tp, pp); @@ -1278,16 +1298,21 @@ 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); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/