[PATCH] x86: partially undo "fix build with gcc 7"

[PATCH] x86: partially undo "fix build with gcc 7"

[Jan Beulich]

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While f32400e90c ("x86: fix build with gcc 7")'s change to
compat_array_access_ok() is necessary, I had blindly and needlessly
also added it to array_access_ok(). There's no conditional expression
involved there, so undo it.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
No ARM counterpart, as Julien means to remove the macro anyway.

--- a/xen/include/asm-x86/x86_64/uaccess.h
+++ b/xen/include/asm-x86/x86_64/uaccess.h
@@ -42,7 +42,7 @@ extern void *xlat_malloc(unsigned long *
 
 #define array_access_ok(addr, count, size) \
     (likely(((count) ?: 0UL) < (~0UL / (size))) && \
-     access_ok(addr, 0 + (count) * (size)))
+     access_ok(addr, (count) * (size)))
 
 #define __compat_addr_ok(d, addr) \
     ((unsigned long)(addr) < HYPERVISOR_COMPAT_VIRT_START(d))




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x86: partially undo "fix build with gcc 7"

While f32400e90c ("x86: fix build with gcc 7")'s change to
compat_array_access_ok() is necessary, I had blindly and needlessly
also added it to array_access_ok(). There's no conditional expression
involved there, so undo it.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
No ARM counterpart, as Julien means to remove the macro anyway.

--- a/xen/include/asm-x86/x86_64/uaccess.h
+++ b/xen/include/asm-x86/x86_64/uaccess.h
@@ -42,7 +42,7 @@ extern void *xlat_malloc(unsigned long *
 
 #define array_access_ok(addr, count, size) \
     (likely(((count) ?: 0UL) < (~0UL / (size))) && \
-     access_ok(addr, 0 + (count) * (size)))
+     access_ok(addr, (count) * (size)))
 
 #define __compat_addr_ok(d, addr) \
     ((unsigned long)(addr) < HYPERVISOR_COMPAT_VIRT_START(d))

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Re: [PATCH] x86: partially undo "fix build with gcc 7"

[Andrew Cooper]

On 31/05/17 08:51, Jan Beulich wrote:
> While f32400e90c ("x86: fix build with gcc 7")'s change to
> compat_array_access_ok() is necessary, I had blindly and needlessly
> also added it to array_access_ok(). There's no conditional expression
> involved there, so undo it.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

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Re: [PATCH] x86: partially undo "fix build with gcc 7"

[Julien Grall]

Hi Jan,

On 31/05/17 08:51, Jan Beulich wrote:
> While f32400e90c ("x86: fix build with gcc 7")'s change to
> compat_array_access_ok() is necessary, I had blindly and needlessly
> also added it to array_access_ok(). There's no conditional expression
> involved there, so undo it.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> ---
> No ARM counterpart, as Julien means to remove the macro anyway.

To double-check, I am CCed on this e-mail because you would like this 
patch in Xen 4.9, right?

Cheers,

-- 
Julien Grall

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Re: [PATCH] x86: partially undo "fix build with gcc 7"

[Jan Beulich]

>>> On 01.06.17 at 13:06, <julien.grall@arm.com> wrote:
> On 31/05/17 08:51, Jan Beulich wrote:
>> While f32400e90c ("x86: fix build with gcc 7")'s change to
>> compat_array_access_ok() is necessary, I had blindly and needlessly
>> also added it to array_access_ok(). There's no conditional expression
>> involved there, so undo it.
>>
>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> ---
>> No ARM counterpart, as Julien means to remove the macro anyway.
> 
> To double-check, I am CCed on this e-mail because you would like this 
> patch in Xen 4.9, right?

No, because of the "No ARM counterpart ..." remark. Of course
I wouldn't mind this going into 4.9, but I did specifically not submit
the patch before branching because the code as is will do there. I
simply didn't want to leave this in place for the longer term.

Jan


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Re: [PATCH] x86: partially undo "fix build with gcc 7"

[Julien Grall]

Hi,

On 01/06/17 12:14, Jan Beulich wrote:
>>>> On 01.06.17 at 13:06, <julien.grall@arm.com> wrote:
>> On 31/05/17 08:51, Jan Beulich wrote:
>>> While f32400e90c ("x86: fix build with gcc 7")'s change to
>>> compat_array_access_ok() is necessary, I had blindly and needlessly
>>> also added it to array_access_ok(). There's no conditional expression
>>> involved there, so undo it.
>>>
>>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>>> ---
>>> No ARM counterpart, as Julien means to remove the macro anyway.
>>
>> To double-check, I am CCed on this e-mail because you would like this
>> patch in Xen 4.9, right?
>
> No, because of the "No ARM counterpart ..." remark. Of course
> I wouldn't mind this going into 4.9, but I did specifically not submit
> the patch before branching because the code as is will do there. I
> simply didn't want to leave this in place for the longer term.

Oh. Yes the patch has been sent and acked by Stefano. Hopefully it will 
get merged soon.

Regarding the patch, I would avoid to add it in Xen 4.9 if it is not 
fixing a regression/critical bug.

Cheers,

-- 
Julien Grall

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