During a "perf buildid-cache --add" command, the section
".note.stapsdt" of the "added" binary is scanned in order to list the
available SDT markers available in a binary. The parts containing the
probes arguments were left unscanned.
The whole section is now parsed; the probe arguments are extracted for
later use.
Signed-off-by: Alexis Berlemont <alexis.berlem...@gmail.com>
---
tools/perf/util/symbol-elf.c | 25 +++++++++++++++++++++++--
tools/perf/util/symbol.h | 1 +
2 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/tools/perf/util/symbol-elf.c b/tools/perf/util/symbol-elf.c
index 99400b0..7725c3f 100644
--- a/tools/perf/util/symbol-elf.c
+++ b/tools/perf/util/symbol-elf.c
@@ -1822,7 +1822,7 @@ void kcore_extract__delete(struct kcore_extract *kce)
static int populate_sdt_note(Elf **elf, const char *data, size_t len,
struct list_head *sdt_notes)
{
- const char *provider, *name;
+ const char *provider, *name, *args;
struct sdt_note *tmp = NULL;
GElf_Ehdr ehdr;
GElf_Addr base_off = 0;
@@ -1881,6 +1881,25 @@ static int populate_sdt_note(Elf **elf, const char
*data, size_t len,
goto out_free_prov;
}
+ args = memchr(name, '\0', data + len - name);
+
+ /*
+ * There is no argument if:
+ * - We reached the end of the note;
+ * - There is not enough room to hold a potential string;
+ * - The argument string is empty or just contains ':'.
+ */
+ if (args == NULL || data + len - args < 2 ||
+ args[1] == ':' || args[1] == '\0')
+ tmp->args = NULL;
+ else {
+ tmp->args = strdup(++args);
+ if (!tmp->args) {
+ ret = -ENOMEM;
+ goto out_free_name;
+ }
+ }
+
if (gelf_getclass(*elf) == ELFCLASS32) {
memcpy(&tmp->addr, &buf, 3 * sizeof(Elf32_Addr));
tmp->bit32 = true;
@@ -1892,7 +1911,7 @@ static int populate_sdt_note(Elf **elf, const char *data,
size_t len,
if (!gelf_getehdr(*elf, &ehdr)) {
pr_debug("%s : cannot get elf header.\n", __func__);
ret = -EBADF;
- goto out_free_name;
+ goto out_free_args;
}
/* Adjust the prelink effect :
@@ -1917,6 +1936,8 @@ static int populate_sdt_note(Elf **elf, const char *data,
size_t len,
list_add_tail(&tmp->note_list, sdt_notes);
return 0;
+out_free_args:
+ free(tmp->args);
out_free_name:
free(tmp->name);
out_free_prov:
diff --git a/tools/perf/util/symbol.h b/tools/perf/util/symbol.h
index 6c358b7..9222c7e 100644
--- a/tools/perf/util/symbol.h
+++ b/tools/perf/util/symbol.h
@@ -351,6 +351,7 @@ int arch__choose_best_symbol(struct symbol *syma, struct
symbol *symb);
struct sdt_note {
char *name; /* name of the note*/
char *provider; /* provider name */
+ char *args;
bool bit32; /* whether the location is 32 bits? */
union { /* location, base and semaphore addrs */
Elf64_Addr a64[3];
--
2.10.2
