[PATCH v4 2/3] perf: kretprobes: offset from reloc_sym if kernel supports it
From: Naveen N. Rao <hidden>
Date: 2017-03-02 23:08:58
Also in:
lkml
Subsystem:
performance events subsystem, the rest · Maintainers:
Peter Zijlstra, Ingo Molnar, Arnaldo Carvalho de Melo, Namhyung Kim, Linus Torvalds
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. Signed-off-by: Naveen N. Rao <redacted> --- 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