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perf probe: Do not access kallsyms when analyzing user binaries

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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
          @<perf_unknown_cmd_config+144>
                  (No matched variables)
          @<list_commands_in_dir+160>
                  (No matched variables)
          @<add_cmdname+0>
                  char*   name
                  size_t  len
                  struct cmdnames*        cmds
  $ perf probe -x ./perf -L add_cmdname
  <add_cmdname@/home/fedora/ksrc/linux-3/tools/perf/util/help.c:0>
        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 <masami.hiramatsu.pt@hitachi.com>
Cc: david lerner <dlernerdroid@gmail.com>
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 <acme@redhat.com>
This commit is contained in:
Masami Hiramatsu 2014-09-17 08:40:54 +00:00 committed by Arnaldo Carvalho de Melo
parent c657f423ae
commit 2b394bc446
3 changed files with 9 additions and 6 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

3
tools/perf/builtin-probe.c
View file

@ -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(&params.line_range, params.target);
ret = show_line_range(&params.line_range, params.target,
params.uprobes);
if (ret < 0)
pr_err_with_code(" Error: Failed to show lines.", ret);
return ret;

9
tools/perf/util/probe-event.c
View file

@ -697,11 +697,11 @@ static int __show_line_range(struct line_range *lr, const char *module)
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;

3
tools/perf/util/probe-event.h
View file

@ -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);