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perf probe: Use existing routine to look for a kernel module by dso->short_name 

We have map_groups__find_by_name() to look at the list of modules that
are in place for a given machine, so use it instead of traversing the
machine dso list, which also includes DSOs for userspace.

When merging the user and kernel DSO lists a bug was introduced where
'perf probe' stopped being able to add probes to modules using its short
name:

  # perf probe -m usbnet --add usbnet_start_xmit
  usbnet_start_xmit is out of .text, skip it.
    Error: Failed to add events.
  #

With this fix it works again:

  # perf probe -m usbnet --add usbnet_start_xmit
  Added new event:
    probe:usbnet_start_xmit (on usbnet_start_xmit in usbnet)

  You can now use it in all perf tools, such as:

  	perf record -e probe:usbnet_start_xmit -aR sleep 1
  #

Reported-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Fixes: 3d39ac5386 ("perf machine: No need to have two DSOs lists")
Link: http://lkml.kernel.org/r/20150924015008.GE1897@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This commit is contained in:
Arnaldo Carvalho de Melo 2015-09-24 11:24:18 -03:00
parent d0d0313c2a
commit 266fa2b222
1 changed files with 7 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

13
tools/perf/util/probe-event.c
View File

@ -270,12 +270,13 @@ static int kernel_get_module_dso(const char *module, struct dso **pdso)
int ret = 0;
if (module) {
list_for_each_entry(dso, &host_machine->dsos.head, node) {
if (!dso->kernel)
continue;
if (strncmp(dso->short_name + 1, module,
dso->short_name_len - 2) == 0)
goto found;
char module_name[128];
snprintf(module_name, sizeof(module_name), "[%s]", module);
map = map_groups__find_by_name(&host_machine->kmaps, MAP__FUNCTION, module_name);
if (map) {
dso = map->dso;
goto found;
}
pr_debug("Failed to find module %s.\n", module);
return -ENOENT;