| Message ID | 1455755707-16844-1-git-send-email-k.kozlowski@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
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 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> >> 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 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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> -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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",
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(-)