From: tip-bot for Wang Nan <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: dsahern@gmail.com, brendan.d.gregg@gmail.com,
xiakaixu@huawei.com, ast@plumgrid.com, daniel@iogearbox.net,
paulus@samba.org, mingo@kernel.org, wangnan0@huawei.com,
lizefan@huawei.com, linux-kernel@vger.kernel.org,
a.p.zijlstra@chello.nl, hekuang@huawei.com, namhyung@kernel.org,
masami.hiramatsu.pt@hitachi.com, hpa@zytor.com, jolsa@kernel.org,
tglx@linutronix.de, acme@redhat.com
Subject: [tip:perf/core] perf tools: Don' t assume that the parser returns non empty evsel list
Date: Wed, 23 Sep 2015 01:43:27 -0700 [thread overview]
Message-ID: <tip-854f736364c659046f066a98fed2fdb10a39577a@git.kernel.org> (raw)
In-Reply-To: <1441523623-152703-2-git-send-email-wangnan0@huawei.com>
Commit-ID: 854f736364c659046f066a98fed2fdb10a39577a
Gitweb: http://git.kernel.org/tip/854f736364c659046f066a98fed2fdb10a39577a
Author: Wang Nan <wangnan0@huawei.com>
AuthorDate: Sun, 6 Sep 2015 07:13:17 +0000
Committer: Arnaldo Carvalho de Melo <acme@redhat.com>
CommitDate: Mon, 21 Sep 2015 18:01:17 -0300
perf tools: Don't assume that the parser returns non empty evsel list
Don't blindly retrieve and use a last element in the lists returned by
parse_events__scanner(), as it may have collected no entries, i.e.
return an empty list.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1441523623-152703-2-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/parse-events.c | 16 ++++++++++++++++
1 file changed, 16 insertions(+)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 0fde529..61c2bc2 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -827,6 +827,11 @@ void parse_events__set_leader(char *name, struct list_head *list)
{
struct perf_evsel *leader;
+ if (list_empty(list)) {
+ WARN_ONCE(true, "WARNING: failed to set leader: empty list");
+ return;
+ }
+
__perf_evlist__set_leader(list);
leader = list_entry(list->next, struct perf_evsel, node);
leader->group_name = name ? strdup(name) : NULL;
@@ -1176,6 +1181,11 @@ int parse_events(struct perf_evlist *evlist, const char *str,
if (!ret) {
struct perf_evsel *last;
+ if (list_empty(&data.list)) {
+ WARN_ONCE(true, "WARNING: event parser found nothing");
+ return -1;
+ }
+
perf_evlist__splice_list_tail(evlist, &data.list);
evlist->nr_groups += data.nr_groups;
last = perf_evlist__last(evlist);
@@ -1285,6 +1295,12 @@ foreach_evsel_in_last_glob(struct perf_evlist *evlist,
struct perf_evsel *last = NULL;
int err;
+ /*
+ * Don't return when list_empty, give func a chance to report
+ * error when it found last == NULL.
+ *
+ * So no need to WARN here, let *func do this.
+ */
if (evlist->nr_entries > 0)
last = perf_evlist__last(evlist);
next prev parent reply other threads:[~2015-09-23 8:44 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-09-06 7:13 [GIT PULL 00/27] perf tools: filtering events using eBPF programs Wang Nan
2015-09-06 7:13 ` [PATCH 01/27] perf tools: Don't write to evsel if parser doesn't collect evsel Wang Nan
2015-09-23 8:43 ` tip-bot for Wang Nan [this message]
2015-09-06 7:13 ` [PATCH 02/27] perf tools: Make perf depend on libbpf Wang Nan
2015-09-06 7:13 ` [PATCH 03/27] perf ebpf: Add the libbpf glue Wang Nan
2015-09-06 7:13 ` [PATCH 04/27] perf tools: Enable passing bpf object file to --event Wang Nan
2015-09-06 7:13 ` [PATCH 05/27] perf record, bpf: Parse and create probe points for BPF programs Wang Nan
2015-09-16 21:43 ` Arnaldo Carvalho de Melo
2015-09-17 2:04 ` Wangnan (F)
2015-09-06 7:13 ` [PATCH 06/27] perf bpf: Collect 'struct perf_probe_event' for bpf_program Wang Nan
2015-09-06 7:13 ` [PATCH 07/27] perf record: Load all eBPF object into kernel Wang Nan
2015-09-06 7:13 ` [PATCH 08/27] perf tools: Add bpf_fd field to evsel and config it Wang Nan
2015-09-06 7:13 ` [PATCH 09/27] perf tools: Attach eBPF program to perf event Wang Nan
2015-09-06 7:13 ` [PATCH 10/27] perf tools: Allow BPF placeholder dummy events to collect --filter options Wang Nan
2015-09-06 7:13 ` [PATCH 11/27] perf tools: Sync setting of real bpf events with placeholder Wang Nan
2015-09-06 7:13 ` [PATCH 12/27] perf record: Add clang options for compiling BPF scripts Wang Nan
2015-09-06 7:13 ` [PATCH 13/27] perf tools: Compile scriptlets to BPF objects when passing '.c' to --event Wang Nan
2015-09-06 7:13 ` [PATCH 14/27] perf test: Enforce LLVM test for BPF test Wang Nan
2015-09-06 7:13 ` [PATCH 15/27] perf test: Add 'perf test BPF' Wang Nan
2015-09-06 7:13 ` [PATCH 16/27] bpf tools: Load a program with different instances using preprocessor Wang Nan
2015-09-06 7:13 ` [PATCH 17/27] perf probe: Reset args and nargs for probe_trace_event when failure Wang Nan
2015-09-06 7:13 ` [PATCH 18/27] perf tools: Add BPF_PROLOGUE config options for further patches Wang Nan
2015-09-16 7:30 ` [tip:perf/core] perf tools: regs_query_register_offset() infrastructure tip-bot for Wang Nan
2015-09-06 7:13 ` [PATCH 19/27] perf tools: Introduce regs_query_register_offset() for x86 Wang Nan
2015-09-14 21:37 ` Arnaldo Carvalho de Melo
2015-09-15 1:36 ` Wangnan (F)
2015-09-16 7:30 ` [tip:perf/core] perf tools: Introduce regs_query_register_offset( ) " tip-bot for Wang Nan
2015-09-06 7:13 ` [PATCH 20/27] perf tools: Add prologue for BPF programs for fetching arguments Wang Nan
2015-09-06 7:13 ` [PATCH 21/27] perf tools: Generate prologue for BPF programs Wang Nan
2015-09-06 7:13 ` [PATCH 22/27] perf tools: Use same BPF program if arguments are identical Wang Nan
2015-09-06 7:13 ` [PATCH 23/27] perf record: Support custom vmlinux path Wang Nan
2015-09-06 7:13 ` [PATCH 24/27] perf probe: Init symbol as kprobe Wang Nan
2015-09-06 7:13 ` [PATCH 25/27] perf tools: Allow BPF program attach to uprobe events Wang Nan
2015-09-06 7:13 ` [PATCH 26/27] perf test: Enforce LLVM test, add kbuild test Wang Nan
2015-09-06 7:13 ` [PATCH 27/27] perf test: Test BPF prologue Wang Nan
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