From f6eb0518f325ef0d6557fbef5c7ebe48a81e74db Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Tue, 12 Jul 2016 19:04:34 +0900 Subject: [PATCH] perf probe: Fix to show correct error message for $vars and $params Fix to show correct error messages for $vars and $params because those special variables requires debug information to find the real variables or function parameters. E.g. without this fix; ---- # perf probe -x /lib64/libc-2.23.so getaddrinfo \$params Failed to write event: Invalid argument Please upgrade your kernel to at least 3.14 to have access to feature $params Error: Failed to add events. ---- Perf ends up with an error, but the message is not correct. With this fix, perf shows correct error message as below. ---- # perf probe -x /lib64/libc-2.23.so getaddrinfo \$params The /usr/lib64/libc-2.23.so file has no debug information. Rebuild with -g, or install an appropriate debuginfo package. Error: Failed to add events. ---- Reported-and-Tested-by: Arnaldo Carvalho de Melo Signed-off-by: Masami Hiramatsu Cc: Ananth N Mavinakayanahalli Cc: Brendan Gregg Cc: Hemant Kumar Cc: Namhyung Kim Cc: Peter Zijlstra Link: http://lkml.kernel.org/r/146831787438.17065.6152436996780110699.stgit@devbox Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/util/probe-event.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c index 2b222a7955c9..fef9768df429 100644 --- a/tools/perf/util/probe-event.c +++ b/tools/perf/util/probe-event.c @@ -1547,7 +1547,9 @@ bool perf_probe_event_need_dwarf(struct perf_probe_event *pev) return true; for (i = 0; i < pev->nargs; i++) - if (is_c_varname(pev->args[i].var)) + if (is_c_varname(pev->args[i].var) || + !strcmp(pev->args[i].var, "$params") || + !strcmp(pev->args[i].var, "$vars")) return true; return false; -- 2.39.5