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SubjectRe: [PATCH 1/2] perf probe: Only call probe_file__get_events() when fd is valid
Em Thu, Nov 05, 2015 at 01:19:24PM +0000, Wang Nan escreveu:
> In system with kprobe enabled but uprobe turned off, 'perf probe -d'
> causes segfault because it calls probe_file__get_events() with a
> negative fd (when deleting uprobe events).
>
> This patch validates fds before calling probe_file__get_events().

Wouldn't this shorter patch be more robust by deferring the validation
to just before using the 'fd' value?

The end result is that probe_file__get_events() will return -ENOENT in
both calls, so ret and ret2 will both be set to -ENOENT, as in your
patch.

Masami?

- Arnaldo

diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 89dbeb92c68e..f04a8318a1a7 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -138,6 +138,9 @@ struct strlist *probe_file__get_rawlist(int fd)
char *p;
struct strlist *sl;

+ if (fd < 0)
+ return NULL;
+
sl = strlist__new(NULL, NULL);

fp = fdopen(dup(fd), "r");

diff --git a/tools/perf/util/probe-file.c b/tools/perf/util/probe-file.c
index 89dbeb92c68e..e5dc8e62f0f1 100644
--- a/tools/perf/util/probe-file.c
+++ b/tools/perf/util/probe-file.c
@@ -169,6 +169,9 @@ static struct strlist *__probe_file__get_namelist(int fd, bool include_group)
struct probe_trace_event tev;
int ret = 0;

+ if (fd < 0)
+ return NULL;
+
memset(&tev, 0, sizeof(tev));
rawlist = probe_file__get_rawlist(fd);
if (!rawlist)

> Signed-off-by: Wang Nan <wangnan0@huawei.com>
> Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
> Cc: Jiri Olsa <jolsa@kernel.org>
> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
> Cc: Namhyung Kim <namhyung@kernel.org>
> ---
> tools/perf/builtin-probe.c | 12 ++++++++++--
> 1 file changed, 10 insertions(+), 2 deletions(-)
>
> diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
> index 132afc9..861aa89 100644
> --- a/tools/perf/builtin-probe.c
> +++ b/tools/perf/builtin-probe.c
> @@ -384,7 +384,11 @@ static int perf_del_probe_events(struct strfilter *filter)
> goto out;
> }
>
> - ret = probe_file__get_events(kfd, filter, klist);
> + if (kfd < 0)
> + ret = -ENOENT;
> + else
> + ret = probe_file__get_events(kfd, filter, klist);
> +
> if (ret == 0) {
> strlist__for_each(ent, klist)
> pr_info("Removed event: %s\n", ent->s);
> @@ -394,7 +398,11 @@ static int perf_del_probe_events(struct strfilter *filter)
> goto error;
> }
>
> - ret2 = probe_file__get_events(ufd, filter, ulist);
> + if (ufd < 0)
> + ret2 = -ENOENT;
> + else
> + ret2 = probe_file__get_events(ufd, filter, ulist);
> +
> if (ret2 == 0) {
> strlist__for_each(ent, ulist)
> pr_info("Removed event: %s\n", ent->s);
> --
> 1.8.3.4


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