* [PATCH] x86_64 add NX mask for PTE entry
@ 2006-10-18 9:15 bibo,mao
2006-10-18 10:58 ` Andi Kleen
0 siblings, 1 reply; 6+ messages in thread
From: bibo,mao @ 2006-10-18 9:15 UTC (permalink / raw)
To: ak; +Cc: linux-kernel
Hi,
If function change_page_attr_addr calls revert_page to revert
to original pte value, mk_pte_phys does not mask NX bit. If NX bit
is set on no NX hardware supported x86_64 machine, there is will
be RSVD type page fault and system will crash. This patch adds NX
mask bit for PTE entry.
Signed-off-by: bibo,mao <bibo.mao@intel.com>
diff --git a/include/asm-x86_64/pgtable.h b/include/asm-x86_64/pgtable.h
index 6899e77..0555c1c 100644
--- a/include/asm-x86_64/pgtable.h
+++ b/include/asm-x86_64/pgtable.h
@@ -366,6 +366,7 @@ static inline pte_t mk_pte_phys(unsigned
{
pte_t pte;
pte_val(pte) = physpage | pgprot_val(pgprot);
+ pte_val(pte) &= __supported_pte_mask;
return pte;
}
^ permalink raw reply related [flat|nested] 6+ messages in thread* Re: [PATCH] x86_64 add NX mask for PTE entry
2006-10-18 9:15 [PATCH] x86_64 add NX mask for PTE entry bibo,mao
@ 2006-10-18 10:58 ` Andi Kleen
2006-10-18 11:23 ` bibo,mao
2006-10-19 1:35 ` bibo,mao
0 siblings, 2 replies; 6+ messages in thread
From: Andi Kleen @ 2006-10-18 10:58 UTC (permalink / raw)
To: bibo,mao; +Cc: linux-kernel
On Wednesday 18 October 2006 11:15, bibo,mao wrote:
> Hi,
> If function change_page_attr_addr calls revert_page to revert
> to original pte value, mk_pte_phys does not mask NX bit. If NX bit
> is set on no NX hardware supported x86_64 machine, there is will
> be RSVD type page fault and system will crash. This patch adds NX
> mask bit for PTE entry.
Hmm, weird. I wonder why that didn't trip up earlier. Did you
actually see that happening?
-Andi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] x86_64 add NX mask for PTE entry
2006-10-18 10:58 ` Andi Kleen
@ 2006-10-18 11:23 ` bibo,mao
2006-10-18 11:45 ` bibo,mao
2006-10-19 1:35 ` bibo,mao
1 sibling, 1 reply; 6+ messages in thread
From: bibo,mao @ 2006-10-18 11:23 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel
Andi Kleen wrote:
> On Wednesday 18 October 2006 11:15, bibo,mao wrote:
>> Hi,
>> If function change_page_attr_addr calls revert_page to revert
>> to original pte value, mk_pte_phys does not mask NX bit. If NX bit
>> is set on no NX hardware supported x86_64 machine, there is will
>> be RSVD type page fault and system will crash. This patch adds NX
>> mask bit for PTE entry.
>
> Hmm, weird. I wonder why that didn't trip up earlier. Did you
> actually see that happening?
I remember previous system worked well on 2.6.12 and 2.6.13 version,
but recently even on older kernel(2.6.9) there will be many times of
page fault error and system crashes at last when rebooting system.
I will paste the oops message tomorrow.
thanks
bibo,mao
>
>
> -Andi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] x86_64 add NX mask for PTE entry
2006-10-18 11:23 ` bibo,mao
@ 2006-10-18 11:45 ` bibo,mao
2006-10-18 13:15 ` Andi Kleen
0 siblings, 1 reply; 6+ messages in thread
From: bibo,mao @ 2006-10-18 11:45 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel
Also I think change_page_attr is buggy. if orginal page is not
large page, when that page's previous attr is reverted revert_page()
function will be called to make that page huge. Indeed I think
there is no need to do this.
thanks
bibo,mao
bibo,mao wrote:
> Andi Kleen wrote:
>> On Wednesday 18 October 2006 11:15, bibo,mao wrote:
>>> Hi,
>>> If function change_page_attr_addr calls revert_page to revert
>>> to original pte value, mk_pte_phys does not mask NX bit. If NX bit
>>> is set on no NX hardware supported x86_64 machine, there is will
>>> be RSVD type page fault and system will crash. This patch adds NX
>>> mask bit for PTE entry.
>>
>> Hmm, weird. I wonder why that didn't trip up earlier. Did you
>> actually see that happening?
> I remember previous system worked well on 2.6.12 and 2.6.13 version,
> but recently even on older kernel(2.6.9) there will be many times of
> page fault error and system crashes at last when rebooting system.
>
> I will paste the oops message tomorrow.
>
> thanks
> bibo,mao
>>
>>
>> -Andi
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] x86_64 add NX mask for PTE entry
2006-10-18 11:45 ` bibo,mao
@ 2006-10-18 13:15 ` Andi Kleen
0 siblings, 0 replies; 6+ messages in thread
From: Andi Kleen @ 2006-10-18 13:15 UTC (permalink / raw)
To: bibo,mao; +Cc: linux-kernel
On Wednesday 18 October 2006 13:45, bibo,mao wrote:
> Also I think change_page_attr is buggy. if orginal page is not
> large page, when that page's previous attr is reverted revert_page()
> function will be called to make that page huge. Indeed I think
> there is no need to do this.
On x86-64 all pages in the direct mapping are initially large pages.
On i386 not necessarily, but it deals with that.
-Andi
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH] x86_64 add NX mask for PTE entry
2006-10-18 10:58 ` Andi Kleen
2006-10-18 11:23 ` bibo,mao
@ 2006-10-19 1:35 ` bibo,mao
1 sibling, 0 replies; 6+ messages in thread
From: bibo,mao @ 2006-10-19 1:35 UTC (permalink / raw)
To: Andi Kleen; +Cc: linux-kernel
The following is oops message everytime when rebooting system,
and oops place is random, my machine is Pentium Dual core with
1G memory, no NX protection supports.
PMD value should be 0x000000003e4001e3 but not 0x800000003e4001e3,
possibly there should be finer dump_pagetable() function to point
out detail error type by page fault error code.
thanks
bibo,mao
Kernel 2.6.19-rc2 on an x86_64
INIT: Sending processes the TERM signal
Unable to handle kernel paging request at ffff81003e5fcde0 RIP:
[<ffffffff812b9918>] __lock_text_start+0x0/0xf
PGD 8063 PUD 9063 PMD 800000003e4001e3 BAD
Oops: 000b [1] SMP
CPU 0
Modules linked in: i2c_dev i2c_core e1000 ext3 jbd
Pid: 4629, comm: default.hotplug Not tainted 2.6.19-rc2 #2
RIP: 0010:[<ffffffff812b9918>] [<ffffffff812b9918>]
__lock_text_start+0x0/0xf
RSP: 0018:ffff81003354fe50 EFLAGS: 00010286
RAX: 00002b756d31c000 RBX: ffff81003e5fcda0 RCX: ffff81000000a400
RDX: ffff810033c02a90 RSI: 0000000000000005 RDI: ffff81003e5fcde0
RBP: ffff81003e8914c0 R08: 00002b756d0f7000 R09: ffff81000000a400
R10: 0000003d31831e88 R11: 0000000000000286 R12: ffff81003f4c6138
R13: 0000000000000000 R14: 0000000000000000 R15: ffff81003354feb8
FS: 0000000000000000(0000) GS:ffffffff81435000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: ffff81003e400fe0 CR3: 0000000034366000 CR4: 00000000000006e0
Process default.hotplug (pid: 4629, threadinfo ffff81003354e000, task
ffff81003e
ee5710)
Stack: ffffffff810659de ffff81003f4c6138 ffff8100373ef8c8 00002b756d0f7000
ffffffff81061959 0000000000000008 ffff810001571860 ffff810033a44558
ffff81003e7a5940 0000000000000000 00000000006c4470 0000000000000000
Call Trace:
[<ffffffff810659de>] unlink_file_vma+0x23/0x3d
[<ffffffff81061959>] free_pgtables+0x66/0xb2
[<ffffffff81067a45>] exit_mmap+0x88/0xe8
[<ffffffff81030196>] mmput+0x31/0xa0
[<ffffffff810350ed>] do_exit+0x1ec/0x82e
[<ffffffff8103dfd7>] sys_rt_sigaction+0x85/0xa4
[<ffffffff810357db>] sys_exit_group+0x0/0xe
[<ffffffff81009b4e>] system_call+0x7e/0x83
Code: f0 ff 0f 79 09 f3 90 83 3f 00 7e f9 eb f2 c3 31 c0 87 07 85
RIP [<ffffffff812b9918>] __lock_text_start+0x0/0xf
RSP <ffff81003354fe50>
CR2: ffff81003e5fcde0
Andi Kleen wrote:
> On Wednesday 18 October 2006 11:15, bibo,mao wrote:
>> Hi,
>> If function change_page_attr_addr calls revert_page to revert
>> to original pte value, mk_pte_phys does not mask NX bit. If NX bit
>> is set on no NX hardware supported x86_64 machine, there is will
>> be RSVD type page fault and system will crash. This patch adds NX
>> mask bit for PTE entry.
>
> Hmm, weird. I wonder why that didn't trip up earlier. Did you
> actually see that happening?
>
>
> -Andi
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/
>
^ permalink raw reply [flat|nested] 6+ messages in thread
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2006-10-18 9:15 [PATCH] x86_64 add NX mask for PTE entry bibo,mao
2006-10-18 10:58 ` Andi Kleen
2006-10-18 11:23 ` bibo,mao
2006-10-18 11:45 ` bibo,mao
2006-10-18 13:15 ` Andi Kleen
2006-10-19 1:35 ` bibo,mao
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