Arm64 ELF section '.note.stapsdt' uses string format "-4@[sp, NUM]" if
the probe is to access data in stack, e.g. below is an example for
dumping Arm64 ELF file and shows the argument format:
Arguments: -4@[sp, 12] -4@[sp, 8] -4@[sp, 4]
Comparing against other archs' argument format, Arm64's argument
introduces an extra space character in the middle of square brackets,
due to argv_split() uses space as splitter, the argument is wrongly
divided into two items.
To support Arm64 SDT, this patch fixes up for this case, if any item
contains sub string "[sp", concatenates the two continuous items. And
adds the detailed explaination in comment.
Signed-off-by: Leo Yan <leo....@linaro.org>
---
tools/perf/util/probe-file.c | 38 ++++++++++++++++++++++++++++++++++--
1 file changed, 36 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index bbecb449ea94..52273542e6ef 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -794,6 +794,8 @@ static char *synthesize_sdt_probe_command(struct sdt_note
*note,
char *ret = NULL;
int i, args_count, err;
unsigned long long ref_ctr_offset;
+ char *arg;
+ int arg_idx = 0;
if (strbuf_init(&buf, 32) < 0)
return NULL;
@@ -818,11 +820,43 @@ static char *synthesize_sdt_probe_command(struct sdt_note
*note,
if (args == NULL)
goto error;
- for (i = 0; i < args_count; ++i) {
- if (synthesize_sdt_probe_arg(&buf, i, args[i]) < 0) {
+ for (i = 0; i < args_count; ) {
+ /*
+ * FIXUP: Arm64 ELF section '.note.stapsdt' uses string
+ * format "-4@[sp, NUM]" if a probe is to access data in
+ * the stack, e.g. below is an example for the SDT
+ * Arguments:
+ *
+ * Arguments: -4@[sp, 12] -4@[sp, 8] -4@[sp, 4]
+ *
+ * Since the string introduces an extra space character
+ * in the middle of square brackets, the argument is
+ * divided into two items. Fixup for this case, if an
+ * item contains sub string "[sp,", need to concatenate
+ * the two items.
+ */
+ if (strstr(args[i], "[sp,") && (i+1) < args_count) {
+ err = asprintf(&arg, "%s %s", args[i],
args[i+1]);
+ i += 2;
+ } else {
+ err = asprintf(&arg, "%s", args[i]);
+ i += 1;
+ }
+
+ /* Failed to allocate memory */
+ if (err < 0) {
argv_free(args);
goto error;
}
+
+ if (synthesize_sdt_probe_arg(&buf, arg_idx, arg) < 0) {
+ free(arg);
+ argv_free(args);
+ goto error;
+ }
+
+ free(arg);
+ arg_idx++;
}
argv_free(args);
--
2.17.1
