Re: linux-next: Tree for Sep 18 (objtool)

From: Randy Dunlap
Date: Thu Sep 19 2019 - 17:09:43 EST


On 9/19/19 12:40 PM, Josh Poimboeuf wrote:
> On Thu, Sep 19, 2019 at 12:21:46PM -0700, Randy Dunlap wrote:
>> On 9/19/19 9:51 AM, Josh Poimboeuf wrote:
>>> On Wed, Sep 18, 2019 at 09:04:21PM -0700, Randy Dunlap wrote:
>>>> On 9/18/19 3:10 PM, Mark Brown wrote:
>>>>> Hi all,
>>>>>
>>>>> Changes since 20190917:
>>>>>
>>>>
>>>> on x86_64:
>>>>
>>>> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: i915_gem_execbuffer2_ioctl()+0x2fb: call to gen8_canonical_addr() with UACCESS enabled
>>>>
>>>> using
>>>>> gcc --version
>>>> gcc (SUSE Linux) 7.4.1 20190424 [gcc-7-branch revision 270538]
>>>>
>>>> .o and .config files are attached.
>>>
>>> Does this fix it?
>>
>> This patch produces this message:
>>
>> drivers/gpu/drm/i915/gem/i915_gem_execbuffer.o: warning: objtool: i915_gem_execbuffer2_ioctl()+0x2fb: call to sign_extend64.constprop.20() with UACCESS enabled
>
> Ha, ok. I guess we have to __always_inline that one too...

Yes, that takes care of the objtool warning. Thanks.

Acked-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx> # build-tested

> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> index b5f6937369ea..7e111cb5b14b 100644
> --- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> +++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
> @@ -284,7 +284,7 @@ struct i915_execbuffer {
> * canonical form [63:48] == [47]."
> */
> #define GEN8_HIGH_ADDRESS_BIT 47
> -static inline u64 gen8_canonical_addr(u64 address)
> +static __always_inline u64 gen8_canonical_addr(u64 address)
> {
> return sign_extend64(address, GEN8_HIGH_ADDRESS_BIT);
> }
> diff --git a/include/linux/bitops.h b/include/linux/bitops.h
> index cf074bce3eb3..fae10792b198 100644
> --- a/include/linux/bitops.h
> +++ b/include/linux/bitops.h
> @@ -151,7 +151,7 @@ static inline __s32 sign_extend32(__u32 value, int index)
> * @value: value to sign extend
> * @index: 0 based bit index (0<=index<64) to sign bit
> */
> -static inline __s64 sign_extend64(__u64 value, int index)
> +static __always_inline __s64 sign_extend64(__u64 value, int index)
> {
> __u8 shift = 63 - index;
> return (__s64)(value << shift) >> shift;
>


--
~Randy