checkpatch: enable volatile warning
Checks
Commit Message
Enable volatile considered harmful warning since use of volatile
is suspect.
Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
---
devtools/checkpatches.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Comments
10/03/2021 12:04, Dharmik Thakkar:
> Enable volatile considered harmful warning since use of volatile
> is suspect.
>
> Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
> Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
git grep -w volatile | wc -l
1796
How much is it suspect?
On Wed, 10 Mar 2021 12:10:01 +0100
Thomas Monjalon <thomas@monjalon.net> wrote:
> 10/03/2021 12:04, Dharmik Thakkar:
> > Enable volatile considered harmful warning since use of volatile
> > is suspect.
> >
> > Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
> > Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
> > Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
>
> git grep -w volatile | wc -l
> 1796
>
> How much is it suspect?
>
>
Many seem to be unsafe.
testpmd: uses flags values in unsafe manner
it also uses volatile when accessing hardware registers
test-alarm is expecting that alarm() is a signal
(it is not)
test-atomic is ok
test-barrier is doing barriers and not using __atomic
drivers use volatile to mark hardware registers.
It is still true volatile is not enough are not weak memory model.
Hi,
Apologies for the delayed response!
> On Mar 10, 2021, at 9:10 AM, Stephen Hemminger <stephen@networkplumber.org> wrote:
>
> On Wed, 10 Mar 2021 12:10:01 +0100
> Thomas Monjalon <thomas@monjalon.net> wrote:
>
>> 10/03/2021 12:04, Dharmik Thakkar:
>>> Enable volatile considered harmful warning since use of volatile
>>> is suspect.
>>>
>>> Suggested-by: Stephen Hemminger <stephen@networkplumber.org>
>>> Signed-off-by: Dharmik Thakkar <dharmik.thakkar@arm.com>
>>> Reviewed-by: Ruifeng Wang <ruifeng.wang@arm.com>
>>
>> git grep -w volatile | wc -l
>> 1796
>>
>> How much is it suspect?
>>
>>
>
> Many seem to be unsafe.
> testpmd: uses flags values in unsafe manner
> it also uses volatile when accessing hardware registers
>
> test-alarm is expecting that alarm() is a signal
> (it is not)
>
> test-atomic is ok
> test-barrier is doing barriers and not using __atomic
>
> drivers use volatile to mark hardware registers.
>
> It is still true volatile is not enough are not weak memory model.
Agree, and this warning should help avoid such unsafe / incorrect use of volatile for future patches.
@@ -29,7 +29,7 @@ options="$options --max-line-length=$length"
options="$options --show-types"
options="$options --ignore=LINUX_VERSION_CODE,ENOSYS,\
FILE_PATH_CHANGES,MAINTAINERS_STYLE,SPDX_LICENSE_TAG,\
-VOLATILE,PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
+PREFER_PACKED,PREFER_ALIGNED,PREFER_PRINTF,\
PREFER_KERNEL_TYPES,PREFER_FALLTHROUGH,BIT_MACRO,CONST_STRUCT,\
SPLIT_STRING,LONG_LINE_STRING,C99_COMMENT_TOLERANCE,\
LINE_SPACING,PARENTHESIS_ALIGNMENT,NETWORKING_BLOCK_COMMENT_STYLE,\