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 getting ref_reloc_sym from machine->vmlinux_maps.
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>
---
tools/perf/util/probe-event.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index c5e1338..75d41ee 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2540,7 +2540,19 @@ static int find_probe_trace_events_from_map(struct
perf_probe_event *pev,
}
if (!pev->uprobes && !pp->retprobe) {
- kmap = map__kmap(map);
+ struct machine *machine;
+ struct map *vmlinux_map = NULL;
+
+ if (map->groups && map->groups->machine) {
+ machine = map->groups->machine;
+ vmlinux_map = machine->vmlinux_maps[MAP__FUNCTION];
+ }
+
+ if (vmlinux_map)
+ kmap = map__kmap(vmlinux_map);
+ else
+ kmap = map__kmap(map);
+
reloc_sym = kmap->ref_reloc_sym;
if (!reloc_sym) {
pr_warning("Relocated base symbol is not found!\n");
--
2.3.3.220.g9ab698f
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