perf probe: Add union member access support
Union members can be accessed with '.' or '->' like data structure
member access
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Acked-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/CANFS6baeuSBxPGQ8SUZWZErJ2bWs-Nojg+FSo138E1QK8bJJig@mail.gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/probe-finder.c b/tools/perf/util/probe-finder.c
index 526ba56..1daf5c1 100644
--- a/tools/perf/util/probe-finder.c
+++ b/tools/perf/util/probe-finder.c
@@ -525,8 +525,10 @@
return -ENOENT;
}
/* Verify it is a data structure */
- if (dwarf_tag(&type) != DW_TAG_structure_type) {
- pr_warning("%s is not a data structure.\n", varname);
+ tag = dwarf_tag(&type);
+ if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
+ pr_warning("%s is not a data structure nor an union.\n",
+ varname);
return -EINVAL;
}
@@ -539,8 +541,9 @@
*ref_ptr = ref;
} else {
/* Verify it is a data structure */
- if (tag != DW_TAG_structure_type) {
- pr_warning("%s is not a data structure.\n", varname);
+ if (tag != DW_TAG_structure_type && tag != DW_TAG_union_type) {
+ pr_warning("%s is not a data structure nor an union.\n",
+ varname);
return -EINVAL;
}
if (field->name[0] == '[') {
@@ -567,10 +570,15 @@
}
/* Get the offset of the field */
- ret = die_get_data_member_location(die_mem, &offs);
- if (ret < 0) {
- pr_warning("Failed to get the offset of %s.\n", field->name);
- return ret;
+ if (tag == DW_TAG_union_type) {
+ offs = 0;
+ } else {
+ ret = die_get_data_member_location(die_mem, &offs);
+ if (ret < 0) {
+ pr_warning("Failed to get the offset of %s.\n",
+ field->name);
+ return ret;
+ }
}
ref->offset += (long)offs;