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  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]
Date:	Mon, 10 Mar 2014 09:45:52 -0700
From:	"H. Peter Anvin" <hpa@...or.com>
To:	David Vrabel <david.vrabel@...rix.com>,
	linux-kernel@...r.kernel.org
CC:	x86@...r.kernel.org, Thomas Gleixner <tglx@...utronix.de>,
	Ingo Molnar <mingo@...hat.com>, xen-devel@...ts.xen.org
Subject: Re: [PATCHv1] x86: don't schedule when handling #NM exception

On 03/10/2014 09:17 AM, David Vrabel wrote:
> diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
> index 57409f6..c8078d2 100644
> --- a/arch/x86/kernel/traps.c
> +++ b/arch/x86/kernel/traps.c
> @@ -624,18 +624,13 @@ void math_state_restore(void)
>  	struct task_struct *tsk = current;
>  
>  	if (!tsk_used_math(tsk)) {
> -		local_irq_enable();
> -		/*
> -		 * does a slab alloc which can sleep
> -		 */
> -		if (init_fpu(tsk)) {
> +		if (init_fpu(tsk, GFP_ATOMIC)) {
>  			/*
>  			 * ran out of memory!
>  			 */
> -			do_group_exit(SIGKILL);
> +			force_sig(SIGKILL, tsk);
>  			return;
>  		}
> -		local_irq_disable();
>  	}
>  

OK, answering my own question... you're randomly SIGKILLing processes
because the kernel doesn't have enough memory on hand.

In other words, because Xen is broken you want to break the rest of the
universe.

This is NAKed so hard it isn't even funny.

	-hpa


--
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/

Powered by blists - more mailing lists