From e6d7c91c8c5ea532584056f3e8bf1643310c8ef7 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sun, 22 Mar 2015 20:40:22 +0900 Subject: [PATCH] perf probe: Fix to get ummapped symbol address on kernel Fix to get correctly unmapped symbol address on kernel. This allows us to probe on syscall symbols which are aliases of SyS_ functions with using debuginfo. Without this fix: ---- # ./perf probe -a sys_write Failed to find debug information for address 3b0100 Probe point 'sys_write' not found. Error: Failed to add events. ---- The address 0x3b0100 is a mapped address, and not usable in debuginfo. With this fix: ---- # ./perf probe -a sys_write Added new event: probe:sys_write (on sys_write) You can now use it in all perf tools, such as: perf record -e probe:sys_write -aR sleep 1 ---- Signed-off-by: Masami Hiramatsu Cc: He Kuang Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Wang Nan Link: http://lkml.kernel.org/r/20150322114022.32639.19096.stgit@localhost.localdomain Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 6b95985db5b0..8feac0774c41 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -310,7 +310,10 @@ static int find_alternative_probe_point(struct debuginfo *dinfo, /* Find the address of given function */ map__for_each_symbol_by_name(map, pp->function, sym) { - address = sym->start; + if (uprobes) + address = sym->start; + else + address = map->unmap_ip(map, sym->start); break; } if (!address) { -- 2.20.1