* [PATCH][2.6] Fix 4G/4G and WP test lockup
@ 2003-10-16 7:22 Zwane Mwaikambo
2003-10-16 7:23 ` Ingo Molnar
0 siblings, 1 reply; 2+ messages in thread
From: Zwane Mwaikambo @ 2003-10-16 7:22 UTC (permalink / raw)
To: Linux Kernel; +Cc: Ingo Molnar, Andrew Morton, William Lee Irwin III
Hi Ingo,
It looks like when we do the WP test and trigger a
(write) protection fault, the 4G/4G page fault handling path doesn't
expect this kind of fault and instead results in recursive fault handling
(or so it appears).
How does the following look?
Index: linux-2.6.0-test7-mm1/arch/i386/mm/fault.c
===================================================================
RCS file: /build/cvsroot/linux-2.6.0-test7-mm1/arch/i386/mm/fault.c,v
retrieving revision 1.1.1.1
diff -u -p -B -r1.1.1.1 fault.c
--- linux-2.6.0-test7-mm1/arch/i386/mm/fault.c 15 Oct 2003 09:01:14 -0000 1.1.1.1
+++ linux-2.6.0-test7-mm1/arch/i386/mm/fault.c 16 Oct 2003 06:42:42 -0000
@@ -260,8 +260,12 @@ asmlinkage void do_page_fault(struct pt_
/*
* On 4/4 all kernels faults are either bugs, vmalloc or prefetch
*/
- if (unlikely((regs->xcs & 3) == 0))
+ if (unlikely((regs->xcs & 3) == 0)) {
+ if (error_code & 3)
+ goto bad_area_nosemaphore;
+
goto vmalloc_fault;
+ }
#else
if (unlikely(address >= TASK_SIZE)) {
if (!(error_code & 5))
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH][2.6] Fix 4G/4G and WP test lockup
2003-10-16 7:22 [PATCH][2.6] Fix 4G/4G and WP test lockup Zwane Mwaikambo
@ 2003-10-16 7:23 ` Ingo Molnar
0 siblings, 0 replies; 2+ messages in thread
From: Ingo Molnar @ 2003-10-16 7:23 UTC (permalink / raw)
To: Zwane Mwaikambo; +Cc: Linux Kernel, Andrew Morton, William Lee Irwin III
fine with me.
Ingo
On Thu, 16 Oct 2003, Zwane Mwaikambo wrote:
> Hi Ingo,
> It looks like when we do the WP test and trigger a
> (write) protection fault, the 4G/4G page fault handling path doesn't
> expect this kind of fault and instead results in recursive fault handling
> (or so it appears).
>
> How does the following look?
>
> Index: linux-2.6.0-test7-mm1/arch/i386/mm/fault.c
> ===================================================================
> RCS file: /build/cvsroot/linux-2.6.0-test7-mm1/arch/i386/mm/fault.c,v
> retrieving revision 1.1.1.1
> diff -u -p -B -r1.1.1.1 fault.c
> --- linux-2.6.0-test7-mm1/arch/i386/mm/fault.c 15 Oct 2003 09:01:14 -0000 1.1.1.1
> +++ linux-2.6.0-test7-mm1/arch/i386/mm/fault.c 16 Oct 2003 06:42:42 -0000
> @@ -260,8 +260,12 @@ asmlinkage void do_page_fault(struct pt_
> /*
> * On 4/4 all kernels faults are either bugs, vmalloc or prefetch
> */
> - if (unlikely((regs->xcs & 3) == 0))
> + if (unlikely((regs->xcs & 3) == 0)) {
> + if (error_code & 3)
> + goto bad_area_nosemaphore;
> +
> goto vmalloc_fault;
> + }
> #else
> if (unlikely(address >= TASK_SIZE)) {
> if (!(error_code & 5))
>
^ permalink raw reply [flat|nested] 2+ messages in thread
end of thread, other threads:[~2003-10-16 7:29 UTC | newest]
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2003-10-16 7:22 [PATCH][2.6] Fix 4G/4G and WP test lockup Zwane Mwaikambo
2003-10-16 7:23 ` Ingo Molnar
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