From 2b394bc4468c2f5e6814a8dbb2a923c0448f8497 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Wed, 17 Sep 2014 08:40:54 +0000 Subject: [PATCH] perf probe: Do not access kallsyms when analyzing user binaries Do not access kallsyms to show available variables and show source lines in user binaries. This behavior always requires the root privilege when sysctl sets kernel.kptr_restrict=1, but we don't need it just for analyzing user binaries. Without this patch (by normal user, kptr_restrict=1): ---- $ perf probe -x ./perf -V add_cmdname Failed to init vmlinux path. Error: Failed to show vars. $ perf probe -x ./perf -L add_cmdname Failed to init vmlinux path. Error: Failed to show lines. ---- With this patch: ---- $ perf probe -x ./perf -V add_cmdname Available variables at add_cmdname @ (No matched variables) @ (No matched variables) @ char* name size_t len struct cmdnames* cmds $ perf probe -x ./perf -L add_cmdname 0 void add_cmdname(struct cmdnames *cmds, const char *name, size_t len) 1 { 2 struct cmdname *ent = malloc(sizeof(*ent) + len + 1); 4 ent->len = len; 5 memcpy(ent->name, name, len); 6 ent->name[len] = 0; ... ---- Signed-off-by: Masami Hiramatsu Cc: david lerner Cc: linux-perf-user@vger.kernel.org Cc: yrl.pp-manager.tt@hitachi.com Link: http://lkml.kernel.org/r/20140917084054.3722.73975.stgit@kbuild-f20.novalocal [ Added missing 'bool user' argument to the !DWARF show_line_range() stub ] Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-probe.c | 3 ++- tools/perf/util/probe-event.c | 9 +++++---- tools/perf/util/probe-event.h | 3 ++- 3 files changed, 9 insertions(+), 6 deletions(-) diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c index 4d6858dbebea..04412b4770a2 100644 --- a/tools/perf/builtin-probe.c +++ b/tools/perf/builtin-probe.c @@ -472,7 +472,8 @@ __cmd_probe(int argc, const char **argv, const char *prefix __maybe_unused) usage_with_options(probe_usage, options); } - ret = show_line_range(¶ms.line_range, params.target); + ret = show_line_range(¶ms.line_range, params.target, + params.uprobes); if (ret < 0) pr_err_with_code(" Error: Failed to show lines.", ret); return ret; diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index f73595fc0627..be37b5aca335 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -697,11 +697,11 @@ end: return ret; } -int show_line_range(struct line_range *lr, const char *module) +int show_line_range(struct line_range *lr, const char *module, bool user) { int ret; - ret = init_symbol_maps(false); + ret = init_symbol_maps(user); if (ret < 0) return ret; ret = __show_line_range(lr, module); @@ -776,7 +776,7 @@ int show_available_vars(struct perf_probe_event *pevs, int npevs, int i, ret = 0; struct debuginfo *dinfo; - ret = init_symbol_maps(false); + ret = init_symbol_maps(pevs->uprobes); if (ret < 0) return ret; @@ -822,7 +822,8 @@ static int try_to_find_probe_trace_events(struct perf_probe_event *pev, } int show_line_range(struct line_range *lr __maybe_unused, - const char *module __maybe_unused) + const char *module __maybe_unused, + bool user __maybe_unused) { pr_warning("Debuginfo-analysis is not supported.\n"); return -ENOSYS; diff --git a/tools/perf/util/probe-event.h b/tools/perf/util/probe-event.h index 776c9347a3b6..e01e9943139f 100644 --- a/tools/perf/util/probe-event.h +++ b/tools/perf/util/probe-event.h @@ -128,7 +128,8 @@ extern int add_perf_probe_events(struct perf_probe_event *pevs, int npevs, bool force_add); extern int del_perf_probe_events(struct strlist *dellist); extern int show_perf_probe_events(void); -extern int show_line_range(struct line_range *lr, const char *module); +extern int show_line_range(struct line_range *lr, const char *module, + bool user); extern int show_available_vars(struct perf_probe_event *pevs, int npevs, int max_probe_points, const char *module, struct strfilter *filter, bool externs); -- 2.20.1