From: Andrew Morton <akpm@linux-foundation.org>
To: Jiri Slaby <jslaby@suse.cz>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2 4/4] fork: free thread in copy_process on failure
Date: Thu, 31 Mar 2016 15:15:34 -0700 [thread overview]
Message-ID: <20160331151534.ac69555f6eea83020b29211b@linux-foundation.org> (raw)
In-Reply-To: <1459410955-5422-4-git-send-email-jslaby@suse.cz>
On Thu, 31 Mar 2016 09:55:55 +0200 Jiri Slaby <jslaby@suse.cz> wrote:
> When using this program (as root):
>
> ...
>
> ret = ioperm(10, 20, 0);
ah-hah.
> if (ret < 0)
> err(1, "ioperm");
>
> for (a = 0; a < ITER; a++)
> run_forkers();
>
> return 0;
> }
>
> kmemleak reports many occurences of this leak:
> unreferenced object 0xffff8805917c8000 (size 8192):
> comm "fork-leak", pid 2932, jiffies 4295354292 (age 1871.028s)
> hex dump (first 32 bytes):
> ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
> backtrace:
> [<ffffffff814cfbf5>] kmemdup+0x25/0x50
> [<ffffffff8103ab43>] copy_thread_tls+0x6c3/0x9a0
> [<ffffffff81150174>] copy_process+0x1a84/0x5790
> [<ffffffff811dc375>] wake_up_new_task+0x2d5/0x6f0
> [<ffffffff8115411d>] _do_fork+0x12d/0x820
> ...
The missing info here is "due to the leakage of the memory which should
have been freed in arch/x86/kernel/process.c:exit_thread().
prev parent reply other threads:[~2016-03-31 22:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-03-31 7:55 [PATCH v2 1/4] mn10300: let exit_fpu accept a task Jiri Slaby
2016-03-31 7:55 ` [PATCH v2 3/4] exit_thread: accept a task parameter to be exited Jiri Slaby
2016-03-31 7:55 ` [PATCH v2 4/4] fork: free thread in copy_process on failure Jiri Slaby
2016-03-31 22:15 ` Andrew Morton [this message]
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