From: Andrew Morton <akpm@osdl.org>
To: Arkadiusz Miskiewicz <arekm@pld-linux.org>
Cc: linux-kernel@vger.kernel.org,
"viro@parcelfarce.linux.theplanet.co.uk"
<viro@parcelfarce.linux.theplanet.co.uk>,
James Morris <jmorris@redhat.com>,
Stephen Smalley <sds@epoch.ncsc.mil>
Subject: Re: 2.6.0-test9 and sleeping function called from invalid context
Date: Sat, 25 Oct 2003 18:50:55 -0700 [thread overview]
Message-ID: <20031025185055.4d9273ae.akpm@osdl.org> (raw)
In-Reply-To: <200310260045.52094.arekm@pld-linux.org>
Arkadiusz Miskiewicz <arekm@pld-linux.org> wrote:
>
> Debug: sleeping function called from invalid context at
> include/asm/semaphore.h:119
> in_atomic():1, irqs_disabled():0
> Call Trace:
> [<c011dfbb>] __might_sleep+0xab/0xf0
> [<c019ed91>] inode_doinit_with_dentry+0x41/0x5d0
> [<cf9b91b0>] bm_fill_super+0x0/0x40 [binfmt_misc]
> [<c0170904>] d_instantiate+0x64/0x80
> [<cf9b8f30>] bm_register_write+0x150/0x1d0 [binfmt_misc]
> [<cf9b8de0>] bm_register_write+0x0/0x1d0 [binfmt_misc]
> [<c01586ea>] vfs_write+0xca/0x140
> [<c01587ff>] sys_write+0x3f/0x60
> [<c010b37f>] syscall_call+0x7/0xb
Not nice.
fs/binfmt_misc.c:bm_register_write() is doing d_instantiate()
under a write_lock(), and the selinux d_instantiate() hook is
performing sleeping functions.
Now, we can just move the d_instantiate() call to outside the lock:
--- 25/fs/binfmt_misc.c~bm_register_write-locking-fix 2003-10-25 18:39:45.000000000 -0700
+++ 25-akpm/fs/binfmt_misc.c 2003-10-25 18:40:29.000000000 -0700
@@ -529,8 +529,8 @@ static ssize_t bm_register_write(struct
inode->u.generic_ip = e;
inode->i_fop = &bm_entry_operations;
- write_lock(&entries_lock);
d_instantiate(dentry, inode);
+ write_lock(&entries_lock);
list_add(&e->list, &entries);
write_unlock(&entries_lock);
which I think is OK, but the wider question would be: is the SELinux
d_instantiate callout allowed to sleep? A quick audit seems to indicate
that it's OK, but only by luck I think.
next prev parent reply other threads:[~2003-10-26 1:50 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-10-25 22:45 2.6.0-test9 and sleeping function called from invalid context Arkadiusz Miskiewicz
2003-10-26 1:50 ` Andrew Morton [this message]
2003-10-26 5:49 ` Andrew Morton
2003-10-26 8:26 ` viro
2003-10-26 8:41 ` Andrew Morton
2003-10-26 9:41 ` viro
2003-10-26 11:03 ` Manfred Spraul
2003-10-26 17:26 ` Manfred Spraul
2003-10-27 13:52 ` Stephen Smalley
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