Re: [PATCH] mips/oprofile: Fix fallthrough placement

From: Gustavo A. R. Silva
Date: Fri Aug 21 2020 - 05:38:58 EST




On 8/21/20 03:46, He Zhe wrote:
>
>
> On 8/21/20 3:48 PM, Thomas Bogendoerfer wrote:
>> On Thu, Aug 20, 2020 at 08:54:40PM +0800, zhe.he@xxxxxxxxxxxxx wrote:
>>> From: He Zhe <zhe.he@xxxxxxxxxxxxx>
>>>
>>> We want neither
>>> "
>>> include/linux/compiler_attributes.h:201:41: warning: statement will never
>>> be executed [-Wswitch-unreachable]
>>> 201 | # define fallthrough __attribute__((__fallthrough__))
>>> | ^~~~~~~~~~~~~
>>> "
>>> nor
>>> "
>>> include/linux/compiler_attributes.h:201:41: warning: attribute
>>> 'fallthrough' not preceding a case label or default label
>>> 201 | # define fallthrough __attribute__((__fallthrough__))
>>> | ^~~~~~~~~~~~~
>>> "
>>>
>>> It's not worth adding one more macro. Let's simply place the fallthrough
>>> in between the expansions.
>>>
>>> Signed-off-by: He Zhe <zhe.he@xxxxxxxxxxxxx>
>> there is already another patch for the problem, which I've applied
>> to mips-fixes.
>
> You mean the below one?
> https://git.kernel.org/pub/scm/linux/kernel/git/mips/linux.git/commit/?h=mips-fixes&id=5900acb374fe2f4f42bbcb2c84db64f582d917a1
>
> That patch handles the first warning in my commit log but does not handle the
> second one which is introduced since gcc v10.1.0 commit 6c80b1b56dec
> ("Make more bad uses of fallthrough attribute into pedwarns.").
>

This is true.

Thomas, please apply this patch instead of mine. Also, consider adding
the Fixes tag and CC stable due to the non-executable code error, and
my Reviewed-by:

Fixes: c9b029903466 ("MIPS: Use fallthrough for arch/mips")
Cc: stable@xxxxxxxxxxxxxxx
Reviewed-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Thanks
--
Gustavo