From: He Kuang <heku...@huawei.com>
Perf tries to find probe function addresses from map when debuginfo
could not be found.
To the first added function, the value of ref_reloc_sym was set in
maps__set_kallsyms_ref_reloc_sym() and can be obtained from
host_machine->kmaps->maps. After that, new maps are added to
host_machine->kmaps->maps in dso__load_kcore(), all these new added maps
do not have a valid ref_reloc_sym.
When adding a second function, get_target_map() may get a map without
valid ref_reloc_sym, and raise the error "Relocated base symbol is not
found".
Fix this by using kernel_get_ref_reloc_sym() to get ref_reloc_sym.
This problem can be reproduced as following:
$ perf probe --add='sys_write' --add='sys_open'
Relocated base symbol is not found!
Error: Failed to add events.
After this patch:
$ perf probe --add='sys_write' --add='sys_open'
Added new event:
probe:sys_write (on sys_write)
You can now use it in all perf tools, such as:
perf record -e probe:sys_write -aR sleep 1
Added new event:
probe:sys_open (on sys_open)
You can now use it in all perf tools, such as:
perf record -e probe:sys_open -aR sleep 1
Signed-off-by: He Kuang <heku...@huawei.com>
Tested-by: Arnaldo Carvalho de Melo <a...@redhat.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu...@hitachi.com>
Cc: Namhyung Kim <namhy...@kernel.org>
Cc: Peter Zijlstra <a.p.zijls...@chello.nl>
Cc: Wang Nan <wangn...@huawei.com>
Link:
http://lkml.kernel.org/r/1426816616-2394-1-git-send-email-heku...@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com>
---
tools/perf/util/probe-event.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index f272a711ad15..6b95985db5b0 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2507,7 +2507,6 @@ static int find_probe_trace_events_from_map(struct
perf_probe_event *pev,
int max_tevs, const char *target)
{
struct map *map = NULL;
- struct kmap *kmap = NULL;
struct ref_reloc_sym *reloc_sym = NULL;
struct symbol *sym;
struct probe_trace_event *tev;
@@ -2540,8 +2539,7 @@ static int find_probe_trace_events_from_map(struct
perf_probe_event *pev,
}
if (!pev->uprobes && !pp->retprobe) {
- kmap = map__kmap(map);
- reloc_sym = kmap->ref_reloc_sym;
+ reloc_sym = kernel_get_ref_reloc_sym();
if (!reloc_sym) {
pr_warning("Relocated base symbol is not found!\n");
ret = -EINVAL;
--
1.9.3
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