From e2c18168c373c92de476b5592807169941a153f5 Mon Sep 17 00:00:00 2001 From: Arnaldo Carvalho de Melo Date: Fri, 9 Jul 2021 14:52:16 -0300 Subject: [PATCH] libperf: Remove BUG_ON() from library code in get_group_fd() We shouldn't just panic, return a value that doesn't clash with what perf_evsel__open() was already returning in case of error, i.e. errno when sys_perf_event_open() fails. Acked-by: Jiri Olsa Cc: Alexander Shishkin Cc: Ian Rogers Cc: Mark Rutland Cc: Michael Petlan Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Shunsuke Nakamura Link: http://lore.kernel.org/lkml/YOiOA5zOtVH9IBbE@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/lib/perf/evsel.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c index 9ebf712..d888672 100644 --- a/tools/lib/perf/evsel.c +++ b/tools/lib/perf/evsel.c @@ -77,23 +77,30 @@ sys_perf_event_open(struct perf_event_attr *attr, return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags); } -static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread) +static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread, int *group_fd) { struct perf_evsel *leader = evsel->leader; int fd; - if (evsel == leader) - return -1; + if (evsel == leader) { + *group_fd = -1; + return 0; + } /* * Leader must be already processed/open, * if not it's a bug. */ - BUG_ON(!leader->fd); + if (!leader->fd) + return -ENOTCONN; fd = FD(leader, cpu, thread); - BUG_ON(fd == -1); - return fd; + if (fd == -1) + return -EBADF; + + *group_fd = fd; + + return 0; } int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, @@ -133,7 +140,9 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus, for (thread = 0; thread < threads->nr; thread++) { int fd, group_fd; - group_fd = get_group_fd(evsel, cpu, thread); + err = get_group_fd(evsel, cpu, thread, &group_fd); + if (err < 0) + return err; fd = sys_perf_event_open(&evsel->attr, threads->map[thread].pid, -- 2.7.4