On Thu, 2 Mar 2017 23:25:06 +0530
"Naveen N. Rao" <naveen.n....@linux.vnet.ibm.com> wrote:
> We indicate support for accepting sym+offset with kretprobes through a
> line in ftrace README. Parse the same to identify support and choose the
> appropriate format for kprobe_events.
Could you give us an example of this change here? :)
for example, comment of commit 613f050d68a8 .
I think the code is OK, but we need actual example of result.
Thanks,
>
> Signed-off-by: Naveen N. Rao <naveen.n....@linux.vnet.ibm.com>
> ---
> tools/perf/util/probe-event.c | 12 +++++-------
> tools/perf/util/probe-file.c | 7 +++++++
> tools/perf/util/probe-file.h | 1 +
> 3 files changed, 13 insertions(+), 7 deletions(-)
>
> diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
> index 35f5b7b7715c..faf5789902f5 100644
> --- a/tools/perf/util/probe-event.c
> +++ b/tools/perf/util/probe-event.c
> @@ -757,7 +757,9 @@ post_process_kernel_probe_trace_events(struct
> probe_trace_event *tevs,
> }
>
> for (i = 0; i < ntevs; i++) {
> - if (!tevs[i].point.address || tevs[i].point.retprobe)
> + if (!tevs[i].point.address)
> + continue;
> + if (tevs[i].point.retprobe && !kretprobe_offset_is_supported())
> continue;
> /* If we found a wrong one, mark it by NULL symbol */
> if (kprobe_warn_out_range(tevs[i].point.symbol,
> @@ -1528,11 +1530,6 @@ static int parse_perf_probe_point(char *arg, struct
> perf_probe_event *pev)
> return -EINVAL;
> }
>
> - if (pp->retprobe && !pp->function) {
> - semantic_error("Return probe requires an entry function.\n");
> - return -EINVAL;
> - }
> -
> if ((pp->offset || pp->line || pp->lazy_line) && pp->retprobe) {
> semantic_error("Offset/Line/Lazy pattern can't be used with "
> "return probe.\n");
> @@ -2841,7 +2838,8 @@ static int find_probe_trace_events_from_map(struct
> perf_probe_event *pev,
> }
>
> /* Note that the symbols in the kmodule are not relocated */
> - if (!pev->uprobes && !pp->retprobe && !pev->target) {
> + if (!pev->uprobes && !pev->target &&
> + (!pp->retprobe || kretprobe_offset_is_supported())) {
> reloc_sym = kernel_get_ref_reloc_sym();
> if (!reloc_sym) {
> pr_warning("Relocated base symbol is not found!\n");
> diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
> index 8a219cd831b7..1542cd0d6799 100644
> --- a/tools/perf/util/probe-file.c
> +++ b/tools/perf/util/probe-file.c
> @@ -879,6 +879,7 @@ int probe_cache__show_all_caches(struct strfilter *filter)
>
> enum ftrace_readme {
> FTRACE_README_PROBE_TYPE_X = 0,
> + FTRACE_README_KRETPROBE_OFFSET,
> FTRACE_README_END,
> };
>
> @@ -889,6 +890,7 @@ static struct {
> #define DEFINE_TYPE(idx, pat) \
> [idx] = {.pattern = pat, .avail = false}
> DEFINE_TYPE(FTRACE_README_PROBE_TYPE_X, "*type: * x8/16/32/64,*"),
> + DEFINE_TYPE(FTRACE_README_KRETPROBE_OFFSET, "*place (kretprobe): *"),
> };
>
> static bool scan_ftrace_readme(enum ftrace_readme type)
> @@ -939,3 +941,8 @@ bool probe_type_is_available(enum probe_type type)
>
> return true;
> }
> +
> +bool kretprobe_offset_is_supported(void)
> +{
> + return scan_ftrace_readme(FTRACE_README_KRETPROBE_OFFSET);
> +}
> diff --git a/tools/perf/util/probe-file.h b/tools/perf/util/probe-file.h
> index a17a82eff8a0..dbf95a00864a 100644
> --- a/tools/perf/util/probe-file.h
> +++ b/tools/perf/util/probe-file.h
> @@ -65,6 +65,7 @@ struct probe_cache_entry *probe_cache__find_by_name(struct
> probe_cache *pcache,
> const char *group, const char *event);
> int probe_cache__show_all_caches(struct strfilter *filter);
> bool probe_type_is_available(enum probe_type type);
> +bool kretprobe_offset_is_supported(void);
> #else /* ! HAVE_LIBELF_SUPPORT */
> static inline struct probe_cache *probe_cache__new(const char *tgt
> __maybe_unused)
> {
> --
> 2.11.1
>
--
Masami Hiramatsu <mhira...@kernel.org>
