[tip:perf/urgent] perf probe: Fix getting the kernel map

tip-bot for Adrian Hunter
2019-03-22T22:04:13Z

Commit-ID: eaeffeb9838a7c0dec981d258666bfcc0fa6a947
Gitweb: https://git.kernel.org/tip/eaeffeb9838a7c0dec981d258666bfcc0fa6a947
Author: Adrian Hunter <adrian.hunter@intel.com>
AuthorDate: Mon, 4 Mar 2019 15:13:21 +0200
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 11 Mar 2019 11:56:03 -0300

perf probe: Fix getting the kernel map

Since commit 4d99e4136580 ("perf machine: Workaround missing maps for
x86 PTI entry trampolines"), perf tools has been creating more than one
kernel map, however 'perf probe' assumed there could be only one.

Fix by using machine__kernel_map() to get the main kernel map.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Tested-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Cc: Xu Yu <xuyu@linux.alibaba.com>
Fixes: 4d99e4136580 ("perf machine: Workaround missing maps for x86 PTI entry trampolines")
Fixes: d83212d5dd67 ("kallsyms, x86: Export addresses of PTI entry trampolines")
Link: http://lkml.kernel.org/r/2ed432de-e904-85d2-5c36-5897ddc5b23b@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/probe-event.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index a1b8d9649ca7..198e09ff611e 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -160,8 +160,10 @@ static struct map *kernel_get_module_map(const char *module)
if (module && strchr(module, '/'))
return dso__new_map(module);

- if (!module)
- module = "kernel";
+ if (!module) {
+ pos = machine__kernel_map(host_machine);
+ return map__get(pos);
+ }

for (pos = maps__first(maps); pos; pos = map__next(pos)) {
/* short_name is "[module]" */