2019-07-28 23:28:10

by Matteo Croce

Subject: [PATCH] arm64: hw_breakpoint: mark expected switch fall-through

Mark switch cases where we are expecting to fall through,
fixes the following warning:

CC arch/arm64/kernel/hw_breakpoint.o
arch/arm64/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’:
arch/arm64/kernel/hw_breakpoint.c:540:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
^
arch/arm64/kernel/hw_breakpoint.c:542:3: note: here
case 2:
^~~~
arch/arm64/kernel/hw_breakpoint.c:544:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
^
arch/arm64/kernel/hw_breakpoint.c:546:3: note: here
default:
^~~~~~~

Signed-off-by: Matteo Croce <[email protected]>
---
arch/arm64/kernel/hw_breakpoint.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
index dceb84520948..7d846985b133 100644
--- a/arch/arm64/kernel/hw_breakpoint.c
+++ b/arch/arm64/kernel/hw_breakpoint.c
@@ -539,10 +539,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
/* Allow single byte watchpoint. */
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
break;
+ /* fallthrough */
case 2:
/* Allow halfword watchpoints and breakpoints. */
if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
break;
+ /* fallthrough */
default:
return -EINVAL;
}
--
2.21.0

2019-07-28 23:38:21

by Matteo Croce

Subject: Re: [PATCH] arm64: hw_breakpoint: mark expected switch fall-through

Feel free di discard the patch then.
What compiler are you using? I' using gcc version 8.3.0 (Ubuntu/Linaro
8.3.0-6ubuntu1)

On Mon, Jul 29, 2019 at 1:34 AM Gustavo A. R. Silva
<[email protected]> wrote:
>
> Hi Matteo,
>
> I sent a patch for this some minutes ago:
>
> https://lore.kernel.org/patchwork/patch/1106585/
>
> It seems there are more warnings in that file than the ones you are
> addressing.
>
> Thanks
> --
> Gustavo
>
> On 7/28/19 6:27 PM, Matteo Croce wrote:
> > Mark switch cases where we are expecting to fall through,
> > fixes the following warning:
> >
> > CC arch/arm64/kernel/hw_breakpoint.o
> > arch/arm64/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’:
> > arch/arm64/kernel/hw_breakpoint.c:540:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
> > if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
> > ^
> > arch/arm64/kernel/hw_breakpoint.c:542:3: note: here
> > case 2:
> > ^~~~
> > arch/arm64/kernel/hw_breakpoint.c:544:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
> > if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
> > ^
> > arch/arm64/kernel/hw_breakpoint.c:546:3: note: here
> > default:
> > ^~~~~~~
> >
> > Signed-off-by: Matteo Croce <[email protected]>
> > ---
> > arch/arm64/kernel/hw_breakpoint.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
> > index dceb84520948..7d846985b133 100644
> > --- a/arch/arm64/kernel/hw_breakpoint.c
> > +++ b/arch/arm64/kernel/hw_breakpoint.c
> > @@ -539,10 +539,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
> > /* Allow single byte watchpoint. */
> > if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
> > break;
> > + /* fallthrough */
> > case 2:
> > /* Allow halfword watchpoints and breakpoints. */
> > if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
> > break;
> > + /* fallthrough */
> > default:
> > return -EINVAL;
> > }
> >



--
Matteo Croce
per aspera ad upstream

2019-07-28 23:47:57

by Gustavo A. R. Silva

Subject: Re: [PATCH] arm64: hw_breakpoint: mark expected switch fall-through

On 7/28/19 6:36 PM, Matteo Croce wrote:
> Feel free di discard the patch then.
> What compiler are you using? I' using gcc version 8.3.0 (Ubuntu/Linaro
> 8.3.0-6ubuntu1)
>

My bad. My patch address the ones in arch/arm/kernel/hw_breakpoint.c

Your patch should be fine.

--
Gustavo

> On Mon, Jul 29, 2019 at 1:34 AM Gustavo A. R. Silva
> <[email protected]> wrote:
>>
>> Hi Matteo,
>>
>> I sent a patch for this some minutes ago:
>>
>> https://lore.kernel.org/patchwork/patch/1106585/
>>
>> It seems there are more warnings in that file than the ones you are
>> addressing.
>>
>> Thanks
>> --
>> Gustavo
>>
>> On 7/28/19 6:27 PM, Matteo Croce wrote:
>>> Mark switch cases where we are expecting to fall through,
>>> fixes the following warning:
>>>
>>> CC arch/arm64/kernel/hw_breakpoint.o
>>> arch/arm64/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’:
>>> arch/arm64/kernel/hw_breakpoint.c:540:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
>>> ^
>>> arch/arm64/kernel/hw_breakpoint.c:542:3: note: here
>>> case 2:
>>> ^~~~
>>> arch/arm64/kernel/hw_breakpoint.c:544:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
>>> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
>>> ^
>>> arch/arm64/kernel/hw_breakpoint.c:546:3: note: here
>>> default:
>>> ^~~~~~~
>>>
>>> Signed-off-by: Matteo Croce <[email protected]>
>>> ---
>>> arch/arm64/kernel/hw_breakpoint.c | 2 ++
>>> 1 file changed, 2 insertions(+)
>>>
>>> diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
>>> index dceb84520948..7d846985b133 100644
>>> --- a/arch/arm64/kernel/hw_breakpoint.c
>>> +++ b/arch/arm64/kernel/hw_breakpoint.c
>>> @@ -539,10 +539,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
>>> /* Allow single byte watchpoint. */
>>> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
>>> break;
>>> + /* fallthrough */
>>> case 2:
>>> /* Allow halfword watchpoints and breakpoints. */
>>> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
>>> break;
>>> + /* fallthrough */
>>> default:
>>> return -EINVAL;
>>> }
>>>
>
>
>

2019-07-28 23:59:15

by Gustavo A. R. Silva

Subject: Re: [PATCH] arm64: hw_breakpoint: mark expected switch fall-through

Hi Matteo,

I sent a patch for this some minutes ago:

https://lore.kernel.org/patchwork/patch/1106585/

It seems there are more warnings in that file than the ones you are
addressing.

Thanks
--
Gustavo

On 7/28/19 6:27 PM, Matteo Croce wrote:
> Mark switch cases where we are expecting to fall through,
> fixes the following warning:
>
> CC arch/arm64/kernel/hw_breakpoint.o
> arch/arm64/kernel/hw_breakpoint.c: In function ‘hw_breakpoint_arch_parse’:
> arch/arm64/kernel/hw_breakpoint.c:540:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
> ^
> arch/arm64/kernel/hw_breakpoint.c:542:3: note: here
> case 2:
> ^~~~
> arch/arm64/kernel/hw_breakpoint.c:544:7: warning: this statement may fall through [-Wimplicit-fallthrough=]
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
> ^
> arch/arm64/kernel/hw_breakpoint.c:546:3: note: here
> default:
> ^~~~~~~
>
> Signed-off-by: Matteo Croce <[email protected]>
> ---
> arch/arm64/kernel/hw_breakpoint.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/arch/arm64/kernel/hw_breakpoint.c b/arch/arm64/kernel/hw_breakpoint.c
> index dceb84520948..7d846985b133 100644
> --- a/arch/arm64/kernel/hw_breakpoint.c
> +++ b/arch/arm64/kernel/hw_breakpoint.c
> @@ -539,10 +539,12 @@ int hw_breakpoint_arch_parse(struct perf_event *bp,
> /* Allow single byte watchpoint. */
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_1)
> break;
> + /* fallthrough */
> case 2:
> /* Allow halfword watchpoints and breakpoints. */
> if (hw->ctrl.len == ARM_BREAKPOINT_LEN_2)
> break;
> + /* fallthrough */
> default:
> return -EINVAL;
> }
>