* [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON
@ 2016-02-18 0:35 Krzysztof Kozlowski
2016-02-18 1:37 ` Andi Shyti
2016-02-18 9:06 ` Arnd Bergmann
0 siblings, 2 replies; 7+ messages in thread
From: Krzysztof Kozlowski @ 2016-02-18 0:35 UTC (permalink / raw)
To: Sangbeom Kim, Krzysztof Kozlowski, Liam Girdwood, Mark Brown,
linux-kernel, linux-samsung-soc
Cc: jacob.e.keller, Arnd Bergmann
Following BUILD_BUG_ON using a variable fails for some of the compilers
and optimization levels (reported for gcc 4.9):
var = ARRAY_SIZE(s2mps15_regulators);
BUILD_BUG_ON(S2MPS_REGULATOR_MAX < var);
Fix this by using ARRAY_SIZE directly.
Additionally add missing BUILD_BUG_ON check for S2MPS15 device (the
check ensures that internal arrays are big enough to hold data for all
of regulators on all devices).
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
---
Changes since v1:
1. Rewritten description after comments from Jacob.
See results when UBSAN is enabled:
http://arm-soc.lixom.net/buildlogs/arm-soc/v4.5-rc4-39-g0d7baf0/buildall.arm.exynos_defconfig.log.failed
---
drivers/regulator/s2mps11.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/drivers/regulator/s2mps11.c b/drivers/regulator/s2mps11.c
index 3242ffc0cb25..df553fb40d82 100644
--- a/drivers/regulator/s2mps11.c
+++ b/drivers/regulator/s2mps11.c
@@ -1090,26 +1090,27 @@ static int s2mps11_pmic_probe(struct platform_device *pdev)
case S2MPS11X:
s2mps11->rdev_num = ARRAY_SIZE(s2mps11_regulators);
regulators = s2mps11_regulators;
- BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
+ BUILD_BUG_ON(S2MPS_REGULATOR_MAX < ARRAY_SIZE(s2mps11_regulators));
break;
case S2MPS13X:
s2mps11->rdev_num = ARRAY_SIZE(s2mps13_regulators);
regulators = s2mps13_regulators;
- BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
+ BUILD_BUG_ON(S2MPS_REGULATOR_MAX < ARRAY_SIZE(s2mps13_regulators));
break;
case S2MPS14X:
s2mps11->rdev_num = ARRAY_SIZE(s2mps14_regulators);
regulators = s2mps14_regulators;
- BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
+ BUILD_BUG_ON(S2MPS_REGULATOR_MAX < ARRAY_SIZE(s2mps14_regulators));
break;
case S2MPS15X:
s2mps11->rdev_num = ARRAY_SIZE(s2mps15_regulators);
regulators = s2mps15_regulators;
+ BUILD_BUG_ON(S2MPS_REGULATOR_MAX < ARRAY_SIZE(s2mps15_regulators));
break;
case S2MPU02:
s2mps11->rdev_num = ARRAY_SIZE(s2mpu02_regulators);
regulators = s2mpu02_regulators;
- BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
+ BUILD_BUG_ON(S2MPS_REGULATOR_MAX < ARRAY_SIZE(s2mpu02_regulators));
break;
default:
dev_err(&pdev->dev, "Invalid device type: %u\n",
--
2.5.0
^ permalink raw reply related [flat|nested] 7+ messages in thread
* Re: [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON
2016-02-18 0:35 [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON Krzysztof Kozlowski
@ 2016-02-18 1:37 ` Andi Shyti
2016-02-18 1:38 ` Krzysztof Kozlowski
2016-02-18 9:06 ` Arnd Bergmann
1 sibling, 1 reply; 7+ messages in thread
From: Andi Shyti @ 2016-02-18 1:37 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Sangbeom Kim, Liam Girdwood, Mark Brown, linux-kernel,
linux-samsung-soc, jacob.e.keller, Arnd Bergmann
Hi Krzysztof,
> Following BUILD_BUG_ON using a variable fails for some of the compilers
> and optimization levels (reported for gcc 4.9):
> var = ARRAY_SIZE(s2mps15_regulators);
> BUILD_BUG_ON(S2MPS_REGULATOR_MAX < var);
> Fix this by using ARRAY_SIZE directly.
>
> Additionally add missing BUILD_BUG_ON check for S2MPS15 device (the
> check ensures that internal arrays are big enough to hold data for all
> of regulators on all devices).
>
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>
[...]
> case S2MPS11X:
> s2mps11->rdev_num = ARRAY_SIZE(s2mps11_regulators);
Why don't we remove rdev_num at all? It's not used that much
other than in the probe function.
> regulators = s2mps11_regulators;
> - BUILD_BUG_ON(S2MPS_REGULATOR_MAX < s2mps11->rdev_num);
> + BUILD_BUG_ON(S2MPS_REGULATOR_MAX < ARRAY_SIZE(s2mps11_regulators));
> break;
Andi
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON
2016-02-18 1:37 ` Andi Shyti
@ 2016-02-18 1:38 ` Krzysztof Kozlowski
2016-02-18 1:46 ` Andi Shyti
0 siblings, 1 reply; 7+ messages in thread
From: Krzysztof Kozlowski @ 2016-02-18 1:38 UTC (permalink / raw)
To: Andi Shyti
Cc: Sangbeom Kim, Liam Girdwood, Mark Brown, linux-kernel,
linux-samsung-soc, jacob.e.keller, Arnd Bergmann
On 18.02.2016 10:37, Andi Shyti wrote:
> Hi Krzysztof,
>
>> Following BUILD_BUG_ON using a variable fails for some of the compilers
>> and optimization levels (reported for gcc 4.9):
>> var = ARRAY_SIZE(s2mps15_regulators);
>> BUILD_BUG_ON(S2MPS_REGULATOR_MAX < var);
>> Fix this by using ARRAY_SIZE directly.
>>
>> Additionally add missing BUILD_BUG_ON check for S2MPS15 device (the
>> check ensures that internal arrays are big enough to hold data for all
>> of regulators on all devices).
>>
>> Reported-by: Arnd Bergmann <arnd@arndb.de>
>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>>
>
> [...]
>
>> case S2MPS11X:
>> s2mps11->rdev_num = ARRAY_SIZE(s2mps11_regulators);
>
> Why don't we remove rdev_num at all? It's not used that much
> other than in the probe function.
Remove from probe? It is used in probe and removal would make the code
more complicated than it should be.
Best regards,
Krzysztof
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON
2016-02-18 1:38 ` Krzysztof Kozlowski
@ 2016-02-18 1:46 ` Andi Shyti
2016-02-18 1:48 ` Krzysztof Kozlowski
0 siblings, 1 reply; 7+ messages in thread
From: Andi Shyti @ 2016-02-18 1:46 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Sangbeom Kim, Liam Girdwood, Mark Brown, linux-kernel,
linux-samsung-soc, jacob.e.keller, Arnd Bergmann
> >> Following BUILD_BUG_ON using a variable fails for some of the compilers
> >> and optimization levels (reported for gcc 4.9):
> >> var = ARRAY_SIZE(s2mps15_regulators);
> >> BUILD_BUG_ON(S2MPS_REGULATOR_MAX < var);
> >> Fix this by using ARRAY_SIZE directly.
> >>
> >> Additionally add missing BUILD_BUG_ON check for S2MPS15 device (the
> >> check ensures that internal arrays are big enough to hold data for all
> >> of regulators on all devices).
> >>
> >> Reported-by: Arnd Bergmann <arnd@arndb.de>
> >> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
> >>
> >
> > [...]
> >
> >> case S2MPS11X:
> >> s2mps11->rdev_num = ARRAY_SIZE(s2mps11_regulators);
> >
> > Why don't we remove rdev_num at all? It's not used that much
> > other than in the probe function.
>
> Remove from probe? It is used in probe and removal would make the code
> more complicated than it should be.
no, I mean remove it from s2mps11_info. Other than in the probe
this value is used only once in s2mps11_pmic_dt_parse() (which is
called by probe()).
Andi
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON
2016-02-18 1:46 ` Andi Shyti
@ 2016-02-18 1:48 ` Krzysztof Kozlowski
2016-02-18 9:05 ` Arnd Bergmann
0 siblings, 1 reply; 7+ messages in thread
From: Krzysztof Kozlowski @ 2016-02-18 1:48 UTC (permalink / raw)
To: Andi Shyti
Cc: Sangbeom Kim, Liam Girdwood, Mark Brown, linux-kernel,
linux-samsung-soc, jacob.e.keller, Arnd Bergmann
On 18.02.2016 10:46, Andi Shyti wrote:
>>>> Following BUILD_BUG_ON using a variable fails for some of the compilers
>>>> and optimization levels (reported for gcc 4.9):
>>>> var = ARRAY_SIZE(s2mps15_regulators);
>>>> BUILD_BUG_ON(S2MPS_REGULATOR_MAX < var);
>>>> Fix this by using ARRAY_SIZE directly.
>>>>
>>>> Additionally add missing BUILD_BUG_ON check for S2MPS15 device (the
>>>> check ensures that internal arrays are big enough to hold data for all
>>>> of regulators on all devices).
>>>>
>>>> Reported-by: Arnd Bergmann <arnd@arndb.de>
>>>> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
>>>>
>>>
>>> [...]
>>>
>>>> case S2MPS11X:
>>>> s2mps11->rdev_num = ARRAY_SIZE(s2mps11_regulators);
>>>
>>> Why don't we remove rdev_num at all? It's not used that much
>>> other than in the probe function.
>>
>> Remove from probe? It is used in probe and removal would make the code
>> more complicated than it should be.
>
> no, I mean remove it from s2mps11_info. Other than in the probe
> this value is used only once in s2mps11_pmic_dt_parse() (which is
> called by probe()).
Sure, it can be safely removed from s2mps11_info... but it won't affect
this issue and this patch. Still the local variable would be used in
probe leading to compiler optimization choices impacting BUILD_BUG_ON.
BR,
Krzysztof
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON
2016-02-18 1:48 ` Krzysztof Kozlowski
@ 2016-02-18 9:05 ` Arnd Bergmann
0 siblings, 0 replies; 7+ messages in thread
From: Arnd Bergmann @ 2016-02-18 9:05 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Andi Shyti, Sangbeom Kim, Liam Girdwood, Mark Brown, linux-kernel,
linux-samsung-soc, jacob.e.keller
On Thursday 18 February 2016 10:48:39 Krzysztof Kozlowski wrote:
>
> Sure, it can be safely removed from s2mps11_info... but it won't affect
> this issue and this patch. Still the local variable would be used in
> probe leading to compiler optimization choices impacting BUILD_BUG_ON.
A local variable probably works fine, I can test that if we think that
would improve the code.
Arnd
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON
2016-02-18 0:35 [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON Krzysztof Kozlowski
2016-02-18 1:37 ` Andi Shyti
@ 2016-02-18 9:06 ` Arnd Bergmann
1 sibling, 0 replies; 7+ messages in thread
From: Arnd Bergmann @ 2016-02-18 9:06 UTC (permalink / raw)
To: Krzysztof Kozlowski
Cc: Sangbeom Kim, Liam Girdwood, Mark Brown, linux-kernel,
linux-samsung-soc, jacob.e.keller
On Thursday 18 February 2016 09:35:07 Krzysztof Kozlowski wrote:
> Following BUILD_BUG_ON using a variable fails for some of the compilers
> and optimization levels (reported for gcc 4.9):
> var = ARRAY_SIZE(s2mps15_regulators);
> BUILD_BUG_ON(S2MPS_REGULATOR_MAX < var);
> Fix this by using ARRAY_SIZE directly.
>
> Additionally add missing BUILD_BUG_ON check for S2MPS15 device (the
> check ensures that internal arrays are big enough to hold data for all
> of regulators on all devices).
>
> Reported-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
I've verified that this is the exact patch I have successfully tested
on locally and in Olof's autobuilder which reported the problem.
> case S2MPS15X:
> s2mps11->rdev_num = ARRAY_SIZE(s2mps15_regulators);
> regulators = s2mps15_regulators;
> + BUILD_BUG_ON(S2MPS_REGULATOR_MAX < ARRAY_SIZE(s2mps15_regulators));
> break;
>
My version did not add this line, but it seems correct.
Tested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
^ permalink raw reply [flat|nested] 7+ messages in thread
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2016-02-18 0:35 [PATCH v2] regulator: s2mps11: Simplify expression used in BUILD_BUG_ON Krzysztof Kozlowski
2016-02-18 1:37 ` Andi Shyti
2016-02-18 1:38 ` Krzysztof Kozlowski
2016-02-18 1:46 ` Andi Shyti
2016-02-18 1:48 ` Krzysztof Kozlowski
2016-02-18 9:05 ` Arnd Bergmann
2016-02-18 9:06 ` Arnd Bergmann
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