lkml.org 
[lkml]   [2014]   [Nov]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: frequent lockups in 3.18rc4
On Fri, 21 Nov 2014 11:06:41 -0800
Linus Torvalds <torvalds@linux-foundation.org> wrote:

> static noinline int vmalloc_fault(unsigned long address)
> {
> pgd_t *pgd_dst;
> pgdval_t pgd_entry;
> unsigned index = pgd_index(address);
>
> if (index < KERNEL_PGD_BOUNDARY)
> return -1;
>
> pgd_entry = init_mm.pgd[index].pgd;
> if (!pgd_entry)
> return -1;

Should we at least check to see if it is present?

if (!(pgd_entry & 1))
return -1;

?

-- Steve

>
> pgd_dst = __va(PAGE_MASK & read_cr3());
> pgd_dst += index;
>
> if (pgd_dst->pgd)
> return -1;
>
> ACCESS_ONCE(pgd_dst->pgd) = pgd_entry;
> return 0;
> }
> NOKPROBE_SYMBOL(vmalloc_fault);
>
> Hmm? Does anybody see anything fundamentally wrong with this?
>
> Linus



\
 
 \ /
  Last update: 2014-11-21 21:01    [W:0.198 / U:0.256 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site