Re: [PATCH] x86 page fault handler not interrupt safe

[Alan Cox]

> If anybody has such a beast, please try this kernel patch _and_ running
> the F0 0F bug-producing program (search for it on the 'net - it must be

One apparent problem with this implementation

> +	 *
> +	 * This verifies that the fault happens in kernel space
> +	 * (error_code & 4) == 0, and that the fault was not a
> +	 * protection error (error_code & 1) == 0.
>  	 */
> -	if (address >= TASK_SIZE)
> +	if (address >= TASK_SIZE && !(error_code & 5))
>  		goto vmalloc_fault;

address might be from the following vmalloc fault. The error code would
indicate user space, so we would do a bogus user space fix up for vmalloc
space, fault and die.