perf trace: Print the name of a syscall when failing to read its info

When failing to read the tracepoint event format, like currently with
sys_execve, that is not defined via SYSCALL_DEFINE macros and thus
doesn't have an entry in:

  $ ls -d /sys/kernel/debug/tracing/events/syscalls/sys_enter_*exec*
  /sys/kernel/debug/tracing/events/syscalls/sys_enter_kexec_load
  $

Cc: David Ahern <[email protected]>
Cc: Frederic Weisbecker <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: Paul Mackerras <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Stephane Eranian <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Thomas Gleixner <[email protected]>
echo Link: http://lkml.kernel.org/n/tip-`ranpwd -l 24`@git.kernel.org
Link: http://lkml.kernel.org/n/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>

1 files changed, 4 insertions, 1 deletions

diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c
index fb83cfe472e3..ba055103b525 100644
--- a/tools/perf/builtin-trace.c
+++ b/tools/perf/builtin-trace.c
@@ -278,7 +278,10 @@ static struct syscall *trace__syscall_info(struct trace *trace,
 	return &trace->syscalls.table[id];
 
 out_cant_read:
-	printf("Problems reading syscall %d information\n", id);
+	printf("Problems reading syscall %d", id);
+	if (id <= trace->syscalls.max && trace->syscalls.table[id].name != NULL)
+		printf("(%s)", trace->syscalls.table[id].name);
+	puts(" information");
 	return NULL;
 }