From: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
To: Yang Shi <yang.shi@linaro.org>
Cc: josh@joshtriplett.org, linux-kernel@vger.kernel.org,
linaro-kernel@lists.linaro.org
Subject: Re: [PATCH] locktorture: Fix potential memory leak with rw lock test
Date: Sat, 12 Nov 2016 10:02:18 -0800 [thread overview]
Message-ID: <20161112180218.GW4127@linux.vnet.ibm.com> (raw)
In-Reply-To: <1478811999-12696-1-git-send-email-yang.shi@linaro.org>
On Thu, Nov 10, 2016 at 01:06:39PM -0800, Yang Shi wrote:
> When running locktorture module with the below commands with kmemleak enabled:
>
> $ modprobe locktorture torture_type=rw_lock_irq
> $ rmmod locktorture
>
> The below kmemleak got caught:
>
> root@10:~# echo scan > /sys/kernel/debug/kmemleak
> [ 323.197029] kmemleak: 2 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
> root@10:~# cat /sys/kernel/debug/kmemleak
> unreferenced object 0xffffffc07592d500 (size 128):
> comm "modprobe", pid 368, jiffies 4294924118 (age 205.824s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 c3 7b 02 00 00 00 00 00 .........{......
> 00 00 00 00 00 00 00 00 d7 9b 02 00 00 00 00 00 ................
> backtrace:
> [<ffffff80081e5a88>] create_object+0x110/0x288
> [<ffffff80086c6078>] kmemleak_alloc+0x58/0xa0
> [<ffffff80081d5acc>] __kmalloc+0x234/0x318
> [<ffffff80006fa130>] 0xffffff80006fa130
> [<ffffff8008083ae4>] do_one_initcall+0x44/0x138
> [<ffffff800817e28c>] do_init_module+0x68/0x1cc
> [<ffffff800811c848>] load_module+0x1a68/0x22e0
> [<ffffff800811d340>] SyS_finit_module+0xe0/0xf0
> [<ffffff80080836f0>] el0_svc_naked+0x24/0x28
> [<ffffffffffffffff>] 0xffffffffffffffff
> unreferenced object 0xffffffc07592d480 (size 128):
> comm "modprobe", pid 368, jiffies 4294924118 (age 205.824s)
> hex dump (first 32 bytes):
> 00 00 00 00 00 00 00 00 3b 6f 01 00 00 00 00 00 ........;o......
> 00 00 00 00 00 00 00 00 23 6a 01 00 00 00 00 00 ........#j......
> backtrace:
> [<ffffff80081e5a88>] create_object+0x110/0x288
> [<ffffff80086c6078>] kmemleak_alloc+0x58/0xa0
> [<ffffff80081d5acc>] __kmalloc+0x234/0x318
> [<ffffff80006fa22c>] 0xffffff80006fa22c
> [<ffffff8008083ae4>] do_one_initcall+0x44/0x138
> [<ffffff800817e28c>] do_init_module+0x68/0x1cc
> [<ffffff800811c848>] load_module+0x1a68/0x22e0
> [<ffffff800811d340>] SyS_finit_module+0xe0/0xf0
> [<ffffff80080836f0>] el0_svc_naked+0x24/0x28
> [<ffffffffffffffff>] 0xffffffffffffffff
>
> It is because cxt.lwsa and cxt.lrsa don't get freed in module_exit, so free
> them in lock_torture_cleanup() and free writer_tasks if reader_tasks is
> failed at memory allocation.
>
> Signed-off-by: Yang Shi <yang.shi@linaro.org>
Good catch! Queued for review and testing.
Thanx, Paul
> ---
> kernel/locking/locktorture.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/kernel/locking/locktorture.c b/kernel/locking/locktorture.c
> index f8c5af5..d3de04b 100644
> --- a/kernel/locking/locktorture.c
> +++ b/kernel/locking/locktorture.c
> @@ -780,6 +780,10 @@ static void lock_torture_cleanup(void)
> else
> lock_torture_print_module_parms(cxt.cur_ops,
> "End of test: SUCCESS");
> +
> + kfree(cxt.lwsa);
> + kfree(cxt.lrsa);
> +
> end:
> torture_cleanup_end();
> }
> @@ -924,6 +928,8 @@ static int __init lock_torture_init(void)
> GFP_KERNEL);
> if (reader_tasks == NULL) {
> VERBOSE_TOROUT_ERRSTRING("reader_tasks: Out of memory");
> + kfree(writer_tasks);
> + writer_tasks = NULL;
> firsterr = -ENOMEM;
> goto unwind;
> }
> --
> 2.0.2
>
prev parent reply other threads:[~2016-11-12 18:02 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-10 21:06 [PATCH] locktorture: Fix potential memory leak with rw lock test Yang Shi
2016-11-12 18:02 ` Paul E. McKenney [this message]
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=20161112180218.GW4127@linux.vnet.ibm.com \
--to=paulmck@linux.vnet.ibm.com \
--cc=josh@joshtriplett.org \
--cc=linaro-kernel@lists.linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=yang.shi@linaro.org \
/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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.