From: Wang Nan <wangnan0@huawei.com>
To: <acme@redhat.com>, <ast@plumgrid.com>,
<masami.hiramatsu.pt@hitachi.com>, <namhyung@kernel.org>
Cc: <a.p.zijlstra@chello.nl>, <brendan.d.gregg@gmail.com>,
<daniel@iogearbox.net>, <dsahern@gmail.com>, <hekuang@huawei.com>,
<jolsa@kernel.org>, <lizefan@huawei.com>, <paulus@samba.org>,
<wangnan0@huawei.com>, <xiakaixu@huawei.com>, <pi3orama@163.com>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH 01/27] perf tools: Don't write to evsel if parser doesn't collect evsel
Date: Sun, 6 Sep 2015 07:13:17 +0000 [thread overview]
Message-ID: <1441523623-152703-2-git-send-email-wangnan0@huawei.com> (raw)
In-Reply-To: <1441523623-152703-1-git-send-email-wangnan0@huawei.com>
If parse_events__scanner() collects no entry, perf_evlist__last(evlist)
is invalid.
Although it shouldn't happen at this point, before calling
perf_evlist__last(), we should ensure the list is not empty for safety
reason.
There are 3 places need this checking:
1. Before setting cmdline_group_boundary;
2. Before __perf_evlist__set_leader();
3. In foreach_evsel_in_last_glob.
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: https://lkml.kernel.org/n/1441176553-116129-1-git-send-email-wangnan0@huawei.com
[wangnan: Enforce the assumption that parser never collect empty list]
---
tools/perf/util/parse-events.c | 23 ++++++++++++++++++++---
1 file changed, 20 insertions(+), 3 deletions(-)
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c
index 3840176..07ce501 100644
--- a/tools/perf/util/parse-events.c
+++ b/tools/perf/util/parse-events.c
@@ -793,6 +793,11 @@ 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;
@@ -1143,10 +1148,16 @@ int parse_events(struct perf_evlist *evlist, const char *str,
int entries = data.idx - evlist->nr_entries;
struct perf_evsel *last;
+ if (list_empty(&data.list)) {
+ WARN_ONCE(true, "WARNING: event parser found nothing");
+ return -1;
+ }
+
+ last = list_entry(data.list.prev, struct perf_evsel, node);
+ last->cmdline_group_boundary = true;
+
perf_evlist__splice_list_tail(evlist, &data.list, entries);
evlist->nr_groups += data.nr_groups;
- last = perf_evlist__last(evlist);
- last->cmdline_group_boundary = true;
return 0;
}
@@ -1252,7 +1263,13 @@ foreach_evsel_in_last_glob(struct perf_evlist *evlist,
struct perf_evsel *last = NULL;
int err;
- if (evlist->nr_entries > 0)
+ /*
+ * 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 (!list_empty(&evlist->entries))
last = perf_evlist__last(evlist);
do {
--
2.1.0
next prev parent reply other threads:[~2015-09-06 7:15 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 ` Wang Nan [this message]
2015-09-23 8:43 ` [tip:perf/core] perf tools: Don' t assume that the parser returns non empty evsel list tip-bot for Wang Nan
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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