From 2459bd33b3dbb7a34f28c612d595311a6bc7593d Mon Sep 17 00:00:00 2001

From: Vincent Fu <vincent.fu@samsung.com>

Date: Wed, 4 Aug 2021 18:29:05 +0000

Subject: [PATCH] ioengines: fix crash with --enghelp option

Since f6931a1dd35896433c8cc2e10de51372a2c496c4 commands like the

following segfault:

fio --enghelp=sg

fio --enghelp=sg,sg_write_mode

This is because free_ioengine() assumes that td->io_ops is not NULL.

Make this true when free_ioengine() is called by

fio_show_ioengine_help() to avoid the crash.

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>

Signed-off-by: Jens Axboe <axboe@kernel.dk>

---

 ioengines.c | 10 +++++-----

 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/ioengines.c b/ioengines.c

index dd61af07..d08a511a 100644

--- a/ioengines.c

+++ b/ioengines.c

@@ -692,17 +692,17 @@ int fio_show_ioengine_help(const char *engine)

 	}

 	td.o.ioengine = (char *)engine;

-	io_ops = load_ioengine(&td);

+	td.io_ops = load_ioengine(&td);

-	if (!io_ops) {

+	if (!td.io_ops) {

 		log_info("IO engine %s not found\n", engine);

 		return 1;

 	}

-	if (io_ops->options)

-		ret = show_cmd_help(io_ops->options, sep);

+	if (td.io_ops->options)

+		ret = show_cmd_help(td.io_ops->options, sep);

 	else

-		log_info("IO engine %s has no options\n", io_ops->name);

+		log_info("IO engine %s has no options\n", td.io_ops->name);

 	free_ioengine(&td);

 	return ret;

-- 

2.31.1