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* [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt()
@ 2021-03-19 16:24 Peter Maydell
  2021-03-26 13:34 ` Peter Maydell
  2021-04-01 15:58 ` Yoshinori Sato
  0 siblings, 2 replies; 6+ messages in thread
From: Peter Maydell @ 2021-03-19 16:24 UTC (permalink / raw)
  To: qemu-devel; +Cc: Magnus Damm, Philippe Mathieu-Daudé, Yoshinori Sato

In commit 81b3ddaf8772ec we fixed a use of uninitialized data
in read_tcnt(). However this change wasn't enough to placate
Coverity, which is not smart enough to see that if we read a
2 bit field and then handle cases 0, 1, 2 and 3 then there cannot
be a flow of execution through the switch default. Add explicit
default cases which assert that they can't be reached, which
should help silence Coverity.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 hw/timer/renesas_tmr.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/hw/timer/renesas_tmr.c b/hw/timer/renesas_tmr.c
index eed39917fec..d96002e1ee6 100644
--- a/hw/timer/renesas_tmr.c
+++ b/hw/timer/renesas_tmr.c
@@ -146,6 +146,8 @@ static uint16_t read_tcnt(RTMRState *tmr, unsigned size, int ch)
         case CSS_CASCADING:
             tcnt[1] = tmr->tcnt[1];
             break;
+        default:
+            g_assert_not_reached();
         }
         switch (FIELD_EX8(tmr->tccr[0], TCCR, CSS)) {
         case CSS_INTERNAL:
@@ -159,6 +161,8 @@ static uint16_t read_tcnt(RTMRState *tmr, unsigned size, int ch)
         case CSS_EXTERNAL: /* QEMU doesn't implement this */
             tcnt[0] = tmr->tcnt[0];
             break;
+        default:
+            g_assert_not_reached();
         }
     } else {
         tcnt[0] = tmr->tcnt[0];
-- 
2.20.1



^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt()
  2021-03-19 16:24 [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt() Peter Maydell
@ 2021-03-26 13:34 ` Peter Maydell
  2021-03-26 18:49   ` Philippe Mathieu-Daudé
  2021-04-01 15:58 ` Yoshinori Sato
  1 sibling, 1 reply; 6+ messages in thread
From: Peter Maydell @ 2021-03-26 13:34 UTC (permalink / raw)
  To: QEMU Developers; +Cc: Magnus Damm, Philippe Mathieu-Daudé, Yoshinori Sato

ping for review?

thanks
-- PMM

On Fri, 19 Mar 2021 at 16:24, Peter Maydell <peter.maydell@linaro.org> wrote:
>
> In commit 81b3ddaf8772ec we fixed a use of uninitialized data
> in read_tcnt(). However this change wasn't enough to placate
> Coverity, which is not smart enough to see that if we read a
> 2 bit field and then handle cases 0, 1, 2 and 3 then there cannot
> be a flow of execution through the switch default. Add explicit
> default cases which assert that they can't be reached, which
> should help silence Coverity.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
> ---
>  hw/timer/renesas_tmr.c | 4 ++++
>  1 file changed, 4 insertions(+)
>
> diff --git a/hw/timer/renesas_tmr.c b/hw/timer/renesas_tmr.c
> index eed39917fec..d96002e1ee6 100644
> --- a/hw/timer/renesas_tmr.c
> +++ b/hw/timer/renesas_tmr.c
> @@ -146,6 +146,8 @@ static uint16_t read_tcnt(RTMRState *tmr, unsigned size, int ch)
>          case CSS_CASCADING:
>              tcnt[1] = tmr->tcnt[1];
>              break;
> +        default:
> +            g_assert_not_reached();
>          }
>          switch (FIELD_EX8(tmr->tccr[0], TCCR, CSS)) {
>          case CSS_INTERNAL:
> @@ -159,6 +161,8 @@ static uint16_t read_tcnt(RTMRState *tmr, unsigned size, int ch)
>          case CSS_EXTERNAL: /* QEMU doesn't implement this */
>              tcnt[0] = tmr->tcnt[0];
>              break;
> +        default:
> +            g_assert_not_reached();
>          }
>      } else {
>          tcnt[0] = tmr->tcnt[0];
> --
> 2.20.1


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt()
  2021-03-26 13:34 ` Peter Maydell
@ 2021-03-26 18:49   ` Philippe Mathieu-Daudé
  2021-03-29 17:03     ` Philippe Mathieu-Daudé
  0 siblings, 1 reply; 6+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-03-26 18:49 UTC (permalink / raw)
  To: Peter Maydell, QEMU Developers; +Cc: Magnus Damm, Yoshinori Sato

On 3/26/21 2:34 PM, Peter Maydell wrote:
> ping for review?

FYI:
https://www.mail-archive.com/qemu-devel@nongnu.org/msg790977.html

> On Fri, 19 Mar 2021 at 16:24, Peter Maydell <peter.maydell@linaro.org> wrote:
>>
>> In commit 81b3ddaf8772ec we fixed a use of uninitialized data
>> in read_tcnt(). However this change wasn't enough to placate
>> Coverity, which is not smart enough to see that if we read a
>> 2 bit field and then handle cases 0, 1, 2 and 3 then there cannot
>> be a flow of execution through the switch default. Add explicit
>> default cases which assert that they can't be reached, which
>> should help silence Coverity.
>>
>> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>> ---
>>  hw/timer/renesas_tmr.c | 4 ++++
>>  1 file changed, 4 insertions(+)

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt()
  2021-03-26 18:49   ` Philippe Mathieu-Daudé
@ 2021-03-29 17:03     ` Philippe Mathieu-Daudé
  2021-03-29 17:55       ` Peter Maydell
  0 siblings, 1 reply; 6+ messages in thread
From: Philippe Mathieu-Daudé @ 2021-03-29 17:03 UTC (permalink / raw)
  To: Peter Maydell, QEMU Developers; +Cc: Magnus Damm, Yoshinori Sato

Hi Peter,

If you are preparing a qemu-arm pull request, can you
squeeze this patch in?

On 3/26/21 7:49 PM, Philippe Mathieu-Daudé wrote:
> On 3/26/21 2:34 PM, Peter Maydell wrote:
>> ping for review?
> 
> FYI:
> https://www.mail-archive.com/qemu-devel@nongnu.org/msg790977.html
> 
>> On Fri, 19 Mar 2021 at 16:24, Peter Maydell <peter.maydell@linaro.org> wrote:
>>>
>>> In commit 81b3ddaf8772ec we fixed a use of uninitialized data
>>> in read_tcnt(). However this change wasn't enough to placate
>>> Coverity, which is not smart enough to see that if we read a
>>> 2 bit field and then handle cases 0, 1, 2 and 3 then there cannot
>>> be a flow of execution through the switch default. Add explicit
>>> default cases which assert that they can't be reached, which
>>> should help silence Coverity.
>>>
>>> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>>> ---
>>>  hw/timer/renesas_tmr.c | 4 ++++
>>>  1 file changed, 4 insertions(+)
> 
> Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> 


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt()
  2021-03-29 17:03     ` Philippe Mathieu-Daudé
@ 2021-03-29 17:55       ` Peter Maydell
  0 siblings, 0 replies; 6+ messages in thread
From: Peter Maydell @ 2021-03-29 17:55 UTC (permalink / raw)
  To: Philippe Mathieu-Daudé; +Cc: Magnus Damm, QEMU Developers, Yoshinori Sato

On Mon, 29 Mar 2021 at 18:03, Philippe Mathieu-Daudé <f4bug@amsat.org> wrote:
>
> Hi Peter,
>
> If you are preparing a qemu-arm pull request, can you
> squeeze this patch in?

Yep, that was my plan.

thanks
-- PMM


^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt()
  2021-03-19 16:24 [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt() Peter Maydell
  2021-03-26 13:34 ` Peter Maydell
@ 2021-04-01 15:58 ` Yoshinori Sato
  1 sibling, 0 replies; 6+ messages in thread
From: Yoshinori Sato @ 2021-04-01 15:58 UTC (permalink / raw)
  To: Peter Maydell; +Cc: Magnus Damm, qemu-devel, Philippe Mathieu-Daudé

On Sat, 20 Mar 2021 01:24:58 +0900,
Peter Maydell wrote:
> 
> In commit 81b3ddaf8772ec we fixed a use of uninitialized data
> in read_tcnt(). However this change wasn't enough to placate
> Coverity, which is not smart enough to see that if we read a
> 2 bit field and then handle cases 0, 1, 2 and 3 then there cannot
> be a flow of execution through the switch default. Add explicit
> default cases which assert that they can't be reached, which
> should help silence Coverity.
> 
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

Reviewed-by: Yoshinori Sato <ysato@users.sourceforge.jp>

> ---
>  hw/timer/renesas_tmr.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/hw/timer/renesas_tmr.c b/hw/timer/renesas_tmr.c
> index eed39917fec..d96002e1ee6 100644
> --- a/hw/timer/renesas_tmr.c
> +++ b/hw/timer/renesas_tmr.c
> @@ -146,6 +146,8 @@ static uint16_t read_tcnt(RTMRState *tmr, unsigned size, int ch)
>          case CSS_CASCADING:
>              tcnt[1] = tmr->tcnt[1];
>              break;
> +        default:
> +            g_assert_not_reached();
>          }
>          switch (FIELD_EX8(tmr->tccr[0], TCCR, CSS)) {
>          case CSS_INTERNAL:
> @@ -159,6 +161,8 @@ static uint16_t read_tcnt(RTMRState *tmr, unsigned size, int ch)
>          case CSS_EXTERNAL: /* QEMU doesn't implement this */
>              tcnt[0] = tmr->tcnt[0];
>              break;
> +        default:
> +            g_assert_not_reached();
>          }
>      } else {
>          tcnt[0] = tmr->tcnt[0];
> -- 
> 2.20.1
> 

I'm back.
---
Yoshinori Sato


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2021-04-01 16:03 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2021-03-19 16:24 [PATCH for-6.0] hw/timer/renesas_tmr: Add default-case asserts in read_tcnt() Peter Maydell
2021-03-26 13:34 ` Peter Maydell
2021-03-26 18:49   ` Philippe Mathieu-Daudé
2021-03-29 17:03     ` Philippe Mathieu-Daudé
2021-03-29 17:55       ` Peter Maydell
2021-04-01 15:58 ` Yoshinori Sato

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