[PATCH] x86: mm: introduce helper function in fault.c

[PATCH] x86: mm: introduce helper function in fault.c

[Hiroshi Shimamoto]

From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Impact: cleanup

Introduce helper function fault_in_kernel_address() to make editors happy.

Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
---
 arch/x86/mm/fault.c |   15 ++++++++++-----
 1 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index bfac289..27ec123 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -783,6 +783,15 @@ static inline int access_error(unsigned long error_code, int write,
 	return 0;
 }
 
+static int fault_in_kernel_space(unsigned long address)
+{
+#ifdef CONFIG_X86_32
+	return address >= TASK_SIZE;
+#else /* !CONFIG_X86_32 */
+	return address >= TASK_SIZE64;
+#endif /* CONFIG_X86_32 */
+}
+
 /*
  * This routine handles page faults.  It determines the address,
  * and the problem, and then passes it off to one of the appropriate
@@ -832,11 +841,7 @@ void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code)
 	 * (error_code & 4) == 0, and that the fault was not a
 	 * protection error (error_code & 9) == 0.
 	 */
-#ifdef CONFIG_X86_32
-	if (unlikely(address >= TASK_SIZE)) {
-#else
-	if (unlikely(address >= TASK_SIZE64)) {
-#endif
+	if (unlikely(fault_in_kernel_space(address))) {
 		if (!(error_code & (PF_RSVD | PF_USER | PF_PROT))) {
 			if (vmalloc_fault(address) >= 0)
 				return;
-- 
1.6.1.2

Re: [PATCH] x86: mm: introduce helper function in fault.c

[H. Peter Anvin]

Hiroshi Shimamoto wrote:
> From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
> 
> Impact: cleanup
> 
> Introduce helper function fault_in_kernel_address() to make editors happy.
> 
> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>

Applied to tip:x86/mm, however, I had to apply the patch manually.

	-hpa

Re: [PATCH] x86: mm: introduce helper function in fault.c

[Ingo Molnar]

* H. Peter Anvin <hpa@zytor.com> wrote:

> Hiroshi Shimamoto wrote:
>> From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>>
>> Impact: cleanup
>>
>> Introduce helper function fault_in_kernel_address() to make editors happy.
>>
>> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>
> Applied to tip:x86/mm, however, I had to apply the patch manually.

that's because the patch was against tip:master - so that's fine, we have 
some other topics that interact. (tip:core/locking in this case) I resolved 
the conflict in tip/master and pushed it out.

	Ingo

Re: [PATCH] x86: mm: introduce helper function in fault.c

[H. Peter Anvin]

Ingo Molnar wrote:
> * H. Peter Anvin <hpa@zytor.com> wrote:
> 
>> Hiroshi Shimamoto wrote:
>>> From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>>>
>>> Impact: cleanup
>>>
>>> Introduce helper function fault_in_kernel_address() to make editors happy.
>>>
>>> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>> Applied to tip:x86/mm, however, I had to apply the patch manually.
> 
> that's because the patch was against tip:master - so that's fine, we have 
> some other topics that interact. (tip:core/locking in this case) I resolved 
> the conflict in tip/master and pushed it out.
> 

Of course.  I mentioned it just as a warning for screwups on my part (in 
fact, I briefly pushed a totally bogus version since I had made an edit 
but forgotten to "git add" it.)

	-hpa

Re: [PATCH] x86: mm: introduce helper function in fault.c

[Ingo Molnar]

* H. Peter Anvin <hpa@zytor.com> wrote:

> Ingo Molnar wrote:
>> * H. Peter Anvin <hpa@zytor.com> wrote:
>>
>>> Hiroshi Shimamoto wrote:
>>>> From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>>>>
>>>> Impact: cleanup
>>>>
>>>> Introduce helper function fault_in_kernel_address() to make editors happy.
>>>>
>>>> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>>> Applied to tip:x86/mm, however, I had to apply the patch manually.
>>
>> that's because the patch was against tip:master - so that's fine, we 
>> have some other topics that interact. (tip:core/locking in this case) I 
>> resolved the conflict in tip/master and pushed it out.
>>
>
> Of course.  I mentioned it just as a warning for screwups on my part (in  
> fact, I briefly pushed a totally bogus version since I had made an edit  
> but forgotten to "git add" it.)

ok :) Hiroshi, please double-check the end result in tip:master if you have 
some time.

	Ingo

Re: [PATCH] x86: mm: introduce helper function in fault.c

[Hiroshi Shimamoto]

Ingo Molnar wrote:
> * H. Peter Anvin <hpa@zytor.com> wrote:
> 
>> Ingo Molnar wrote:
>>> * H. Peter Anvin <hpa@zytor.com> wrote:
>>>
>>>> Hiroshi Shimamoto wrote:
>>>>> From: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>>>>>
>>>>> Impact: cleanup
>>>>>
>>>>> Introduce helper function fault_in_kernel_address() to make editors happy.
>>>>>
>>>>> Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
>>>> Applied to tip:x86/mm, however, I had to apply the patch manually.
>>> that's because the patch was against tip:master - so that's fine, we 
>>> have some other topics that interact. (tip:core/locking in this case) I 
>>> resolved the conflict in tip/master and pushed it out.
>>>
>> Of course.  I mentioned it just as a warning for screwups on my part (in  
>> fact, I briefly pushed a totally bogus version since I had made an edit  
>> but forgotten to "git add" it.)
> 
> ok :) Hiroshi, please double-check the end result in tip:master if you have 
> some time.

OK, thanks. Will look at tip:master.

Hiroshi