From: Arnaldo Carvalho de Melo <acme@kernel.org>
To: Ingo Molnar <mingo@kernel.org>, Thomas Gleixner <tglx@linutronix.de>
Cc: Jiri Olsa <jolsa@kernel.org>, Namhyung Kim <namhyung@kernel.org>,
Clark Williams <williams@redhat.com>,
linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Adrian Hunter <adrian.hunter@intel.com>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: [PATCH 08/10] perf probe: Set pev->nargs to zero after freeing pev->args entries
Date: Tue, 23 Jul 2019 17:05:28 -0300 [thread overview]
Message-ID: <20190723200530.14090-9-acme@kernel.org> (raw)
In-Reply-To: <20190723200530.14090-1-acme@kernel.org>
From: Arnaldo Carvalho de Melo <acme@redhat.com>
So that, when perf_add_probe_events() fails, like in:
# perf probe icmp_rcv:64 "type=icmph->type"
Failed to find 'icmph' in this function.
Error: Failed to add events.
Segmentation fault (core dumped)
#
We don't segfault.
clear_perf_probe_event() was zeroing the whole pev, and since the switch
to zfree() for the members in the pev, that memset() was removed, which
left nargs with its original value, in the above case 1.
With the memset the same pev could be passed to clear_perf_probe_event()
multiple times, since all it would have would be zeroes, and free()
accepts zero, the loop would not happen and we would just memset it
again to zeroes.
Without it we got that segfault, so zero nargs to keep it like it was,
next cset will avoid calling clear_perf_probe_event() for the same pevs
in case of failure.
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: d8f9da240495 ("perf tools: Use zfree() where applicable")
Link: https://lkml.kernel.org/n/tip-802f2jypnwqsvyavvivs8464@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
---
tools/perf/util/probe-event.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/tools/perf/util/probe-event.c b/tools/perf/util/probe-event.c
index 0c3b55d0617d..4acd3457d39d 100644
--- a/tools/perf/util/probe-event.c
+++ b/tools/perf/util/probe-event.c
@@ -2219,6 +2219,7 @@ void clear_perf_probe_event(struct perf_probe_event *pev)
field = next;
}
}
+ pev->nargs = 0;
zfree(&pev->args);
}
--
2.21.0
next prev parent reply other threads:[~2019-07-23 20:06 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-23 20:05 [GIT PULL] perf/urgent fixes Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 01/10] perf script: Fix --max-blocks man page description Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 02/10] perf script: Improve man page description of metrics Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 03/10] perf script: Fix off by one in brstackinsn IPC computation Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 04/10] perf tools: Fix proper buffer size for feature processing Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 05/10] perf stat: Fix segfault for event group in repeat mode Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 06/10] perf stat: Always separate stalled cycles per insn Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 07/10] perf session: Fix loading of compressed data split across adjacent records Arnaldo Carvalho de Melo
2019-07-23 20:05 ` Arnaldo Carvalho de Melo [this message]
2019-07-23 20:05 ` [PATCH 09/10] perf probe: Avoid calling freeing routine multiple times for same pointer Arnaldo Carvalho de Melo
2019-07-23 20:05 ` [PATCH 10/10] perf build: Do not use -Wshadow on gcc < 4.8 Arnaldo Carvalho de Melo
2019-07-23 21:42 ` [GIT PULL] perf/urgent fixes Ingo Molnar
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20190723200530.14090-9-acme@kernel.org \
--to=acme@kernel.org \
--cc=acme@redhat.com \
--cc=adrian.hunter@intel.com \
--cc=jolsa@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-perf-users@vger.kernel.org \
--cc=mhiramat@kernel.org \
--cc=mingo@kernel.org \
--cc=namhyung@kernel.org \
--cc=tglx@linutronix.de \
--cc=williams@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).