RE: [PATCH perf/core ] [BUGFIX] perf probe: Fix a segfault when removing uprobe events

[åæéå / HIRAMATUïMASAMI]

Hi Arnaldo,

Could you pull this bugfix as an urgent patch, since this fixes a critical
problem?

Thanks,

From: Masami Hiramatsu [mailto:masami.hiramatsu.pt@xxxxxxxxxxx]
>
>Fix a segfault bug and a small mistake in perf probe -d.
>
>Since the "ulist" in perf_del_probe_events is never initialized,
>strlist__add(ulist, *) always causes a segfault when removing
>uprobe events by perf probe -d.
>
>Also, the "str" local variable is never released if fail to
>allocate the "klist". This fixes it too.
>
>This has been introduced by the commit e607f1426b58 ("perf probe:
>Print deleted events in cmd_probe()").
>
>Reported-by: Milian Wolff <milian.wolff@xxxxxxxx>
>Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@xxxxxxxxxxx>
>---
> tools/perf/builtin-probe.c |    7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
>diff --git a/tools/perf/builtin-probe.c b/tools/perf/builtin-probe.c
>index 94385ee..f7882ae 100644
>--- a/tools/perf/builtin-probe.c
>+++ b/tools/perf/builtin-probe.c
>@@ -380,8 +380,11 @@ static int perf_del_probe_events(struct strfilter *filter)
> 		goto out;
>
> 	klist = strlist__new(NULL, NULL);
>-	if (!klist)
>-		return -ENOMEM;
>+	ulist = strlist__new(NULL, NULL);
>+	if (!klist || !ulist) {
>+		ret = -ENOMEM;
>+		goto out;
>+	}
>
> 	ret = probe_file__get_events(kfd, filter, klist);
> 	if (ret == 0) {
>