From 86a19008af5d88d5d523dbfe9b6ede11473e9a7f Mon Sep 17 00:00:00 2001 From: Michael Petlan Date: Tue, 2 Mar 2021 15:41:20 +0100 Subject: perf trace: Fix race in signal handling Since a lot of stuff happens before the SIGINT signal handler is registered (scanning /proc/*, etc.), on bigger systems, such as Cavium Sabre CN99xx, it may happen that first interrupt signal is lost and perf isn't correctly terminated. The reproduction code might look like the following: perf trace -a & PERF_PID=$! sleep 4 kill -INT $PERF_PID The issue has been found on a CN99xx machine with RHEL-8 and the patch fixes it by registering the signal handlers earlier in the init stage. Suggested-by: Jiri Olsa Signed-off-by: Michael Petlan Tested-by: Michael Petlan Cc: Jiri Olsa Link: https://lore.kernel.org/lkml/YEJnaMzH2ctp3PPx@kernel.org/ Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-trace.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) (limited to 'tools/perf/builtin-trace.c') diff --git a/tools/perf/builtin-trace.c b/tools/perf/builtin-trace.c index 85b6a46e85b6..7ec18ff57fc4 100644 --- a/tools/perf/builtin-trace.c +++ b/tools/perf/builtin-trace.c @@ -3964,9 +3964,6 @@ static int trace__run(struct trace *trace, int argc, const char **argv) evlist__config(evlist, &trace->opts, &callchain_param); - signal(SIGCHLD, sig_handler); - signal(SIGINT, sig_handler); - if (forks) { err = evlist__prepare_workload(evlist, &trace->opts.target, argv, false, NULL); if (err < 0) { @@ -4827,6 +4824,8 @@ int cmd_trace(int argc, const char **argv) signal(SIGSEGV, sighandler_dump_stack); signal(SIGFPE, sighandler_dump_stack); + signal(SIGCHLD, sig_handler); + signal(SIGINT, sig_handler); trace.evlist = evlist__new(); trace.sctbl = syscalltbl__new(); -- cgit v1.2.3-59-g8ed1b