linux-kernel - Re: [PATCH][UHCI-DEBUG] Don't kmalloc with BKL held

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1254573359.11691.0.camel@sven.thebigcorporation.com>
Date:	Sat, 03 Oct 2009 05:35:59 -0700
From:	Sven-Thorsten Dietrich <sdietrich@...ell.com>
To:	Frederik Deweerdt <frederik.deweerdt@...og.eu>
Cc:	LKML <linux-kernel@...r.kernel.org>,
	linux-rt-users <linux-rt-users@...r.kernel.org>
Subject: Re: [PATCH][UHCI-DEBUG] Don't kmalloc with BKL held

On Fri, 2009-10-02 at 09:20 +0000, Frederik Deweerdt wrote:
> Hi Sven-Thorsten,
> 
> On Fri, Oct 02, 2009 at 11:12:24AM +0200, Sven-Thorsten Dietrich wrote:
> > Subject: Don't kmalloc with BKL held.
> > From: Sven-Thorsten Dietrich <sdietrich@...e.de>
> > 
> > I'm eyeballing this file for complete removal of lock_kernel but 
> > at first glance, we definitely don't need BKL to kmalloc(). 
> You need to move the unlock_kernel() above the out: label too.
> 

How about this ?

Subject: Don't kmalloc with BKL held.
From: Sven-Thorsten Dietrich sdietrich@...e.de Sat Oct 3 01:27:27 2009 -0700
Date: Sat Oct 3 01:27:27 2009 -0700:
Git: 4f62eb81e827eb857129101e49757d84ac9ee7eb

We don't need BKL to kmalloc

diff --git a/drivers/usb/host/uhci-debug.c b/drivers/usb/host/uhci-debug.c
index e52b954..3fd5602 100644
--- a/drivers/usb/host/uhci-debug.c
+++ b/drivers/usb/host/uhci-debug.c
@@ -494,32 +494,30 @@ static int uhci_debug_open(struct inode *inode, struct file *file)
 {
 	struct uhci_hcd *uhci = inode->i_private;
 	struct uhci_debug *up;
-	int ret = -ENOMEM;
 	unsigned long flags;
 
-	lock_kernel();
 	up = kmalloc(sizeof(*up), GFP_KERNEL);
 	if (!up)
-		goto out;
+		return -ENOMEM;
 
 	up->data = kmalloc(MAX_OUTPUT, GFP_KERNEL);
 	if (!up->data) {
 		kfree(up);
-		goto out;
+		return -ENOMEM;
 	}
 
 	up->size = 0;
+
+	lock_kernel();
 	spin_lock_irqsave(&uhci->lock, flags);
 	if (uhci->is_initialized)
 		up->size = uhci_sprint_schedule(uhci, up->data, MAX_OUTPUT);
 	spin_unlock_irqrestore(&uhci->lock, flags);
 
 	file->private_data = up;
-
-	ret = 0;
-out:
 	unlock_kernel();
-	return ret;
+
+	return 0;
 }
 
 static loff_t uhci_debug_lseek(struct file *file, loff_t off, int whence)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/