Ignore the buildid of running kernel when both of --definition and
--vmlinux is given because that kernel should be off-line.
This also skips post-processing of kprobe event for relocating
symbol and checking blacklist, because it can not be done on
off-line kernel.
E.g. without this fix perf shows an error as below
----
$ perf probe --vmlinux=./vmlinux-arm --definition do_sys_open
./vmlinux-arm with build id 7a1f76dd56e9c4da707cd3d6333f50748141434b not
found, continuing without symbols
Failed to find symbol do_sys_open in kernel
Error: Failed to add events.
----
with this fix, we can get the definition
----
$ perf probe --vmlinux=./vmlinux-arm --definition do_sys_open
p:probe/do_sys_open do_sys_open+0
----
Signed-off-by: Masami Hiramatsu <[email protected]>
---
Changes from v1:
- Update the condition since --definition is introduced.
- Skip post processing because this is not running kernel.
- Update documentation too.
---
tools/perf/Documentation/perf-probe.txt | 2 ++
tools/perf/builtin-probe.c | 10 +++++++++-
tools/perf/util/probe-event.c | 4 ++++
tools/perf/util/symbol-elf.c | 2 +-
4 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/tools/perf/Documentation/perf-probe.txt
b/tools/perf/Documentation/perf-probe.txt
index 56db4d4..e6c9902 100644
--- a/tools/perf/Documentation/perf-probe.txt
+++ b/tools/perf/Documentation/perf-probe.txt
@@ -36,6 +36,8 @@ OPTIONS
-k::
--vmlinux=PATH::
Specify vmlinux path which has debuginfo (Dwarf binary).
+ Only when using this with --definition, you can give an offline
+ vmlinux file.
-m::
--module=MODNAME|PATH::
diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
index 7a3d8c4..b4220cd 100644
--- a/tools/perf/builtin-probe.c
+++ b/tools/perf/builtin-probe.c
@@ -654,8 +654,16 @@ __cmd_probe(int argc, const char **argv, const char
*prefix __maybe_unused)
return ret;
}
break;
- case 'a':
case 'D':
+ /*
+ * If user gives offline vmlinux, ignore buildid, since
+ * --definition doesn't change running kernel.
+ */
+ if (symbol_conf.vmlinux_name)
+ symbol_conf.ignore_vmlinux_buildid = true;
+ /* fall through */
+ case 'a':
+
/* Ensure the last given target is used */
if (params.target && !params.target_used) {
pr_err(" Error: -x/-m must follow the probe
definitions.\n");
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index ad7094d..8dcec0c 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -674,6 +674,10 @@ post_process_kernel_probe_trace_events(struct
probe_trace_event *tevs,
char *tmp;
int i, skipped = 0;
+ /* Skip post process if the target is an offline kernel */
+ if (symbol_conf.ignore_vmlinux_buildid)
+ return 0;
+
reloc_sym = kernel_get_ref_reloc_sym();
if (!reloc_sym) {
pr_warning("Relocated base symbol is not found!\n");
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index a811c13..013cebf 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -685,7 +685,7 @@ int symsrc__init(struct symsrc *ss, struct dso *dso, const
char *name,
}
/* Always reject images with a mismatched build-id: */
- if (dso->has_build_id) {
+ if (dso->has_build_id && !symbol_conf.ignore_vmlinux_buildid) {
u8 build_id[BUILD_ID_SIZE];
if (elf_read_build_id(elf, build_id, BUILD_ID_SIZE) < 0) {
