[v2] Fix a bunch of allmodconfig errors

[PATCH v2 2/2] Kconfig.debug: Provide a little extra FRAME_WARN leeway when KASAN is enabled

Posted by Lee Jones 2 years, 9 months ago

When enabled, KASAN enlarges function's stack-frames.  Pushing quite a
few over the current threshold.  This can mainly be seen on 32-bit
architectures where the present limit (when !GCC) is a lowly
1024-Bytes.

Signed-off-by: Lee Jones <lee@kernel.org>
---
 lib/Kconfig.debug | 1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c3c0b077ade33..82d475168db95 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -399,6 +399,7 @@ config FRAME_WARN
 	default 2048 if GCC_PLUGIN_LATENT_ENTROPY
 	default 2048 if PARISC
 	default 1536 if (!64BIT && XTENSA)
+	default 1280 if KASAN && !64BIT
 	default 1024 if !64BIT
 	default 2048 if 64BIT
 	help
-- 
2.38.1.584.g0f3c55d4c2-goog

Re: [PATCH v2 2/2] Kconfig.debug: Provide a little extra FRAME_WARN leeway when KASAN is enabled

Posted by Nathan Chancellor 2 years, 9 months ago

On Fri, Nov 25, 2022 at 12:07:50PM +0000, Lee Jones wrote:
> When enabled, KASAN enlarges function's stack-frames.  Pushing quite a
> few over the current threshold.  This can mainly be seen on 32-bit
> architectures where the present limit (when !GCC) is a lowly
> 1024-Bytes.
> 
> Signed-off-by: Lee Jones <lee@kernel.org>

Reviewed-by: Nathan Chancellor <nathan@kernel.org>

> ---
>  lib/Kconfig.debug | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c3c0b077ade33..82d475168db95 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -399,6 +399,7 @@ config FRAME_WARN
>  	default 2048 if GCC_PLUGIN_LATENT_ENTROPY
>  	default 2048 if PARISC
>  	default 1536 if (!64BIT && XTENSA)
> +	default 1280 if KASAN && !64BIT
>  	default 1024 if !64BIT
>  	default 2048 if 64BIT
>  	help
> -- 
> 2.38.1.584.g0f3c55d4c2-goog
>

Re: [PATCH v2 2/2] Kconfig.debug: Provide a little extra FRAME_WARN leeway when KASAN is enabled

Posted by Lee Jones 2 years, 9 months ago

On Fri, 25 Nov 2022, Lee Jones wrote:

> When enabled, KASAN enlarges function's stack-frames.  Pushing quite a
> few over the current threshold.  This can mainly be seen on 32-bit
> architectures where the present limit (when !GCC) is a lowly
> 1024-Bytes.
> 
> Signed-off-by: Lee Jones <lee@kernel.org>
> ---
>  lib/Kconfig.debug | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
> index c3c0b077ade33..82d475168db95 100644
> --- a/lib/Kconfig.debug
> +++ b/lib/Kconfig.debug
> @@ -399,6 +399,7 @@ config FRAME_WARN
>  	default 2048 if GCC_PLUGIN_LATENT_ENTROPY
>  	default 2048 if PARISC
>  	default 1536 if (!64BIT && XTENSA)
> +	default 1280 if KASAN && !64BIT
>  	default 1024 if !64BIT
>  	default 2048 if 64BIT
>  	help

Note this also fixes 61 warnings when

  (GCC && !GCC_PLUGIN_LATENT_ENTROPY)

... which as Arnd says should not be enabled by default.  We'll
address that issue once this set has been applied.

-- 
Lee Jones [李琼斯]

Re: [PATCH v2 2/2] Kconfig.debug: Provide a little extra FRAME_WARN leeway when KASAN is enabled

Posted by Arnd Bergmann 2 years, 9 months ago

On Fri, Nov 25, 2022, at 14:40, Lee Jones wrote:
> On Fri, 25 Nov 2022, Lee Jones wrote:
>
>> When enabled, KASAN enlarges function's stack-frames.  Pushing quite a
>> few over the current threshold.  This can mainly be seen on 32-bit
>> architectures where the present limit (when !GCC) is a lowly
>> 1024-Bytes.
>> 
>> Signed-off-by: Lee Jones <lee@kernel.org>
>> ---
>>  lib/Kconfig.debug | 1 +
>>  1 file changed, 1 insertion(+)
>> 
>> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
>> index c3c0b077ade33..82d475168db95 100644
>> --- a/lib/Kconfig.debug
>> +++ b/lib/Kconfig.debug
>> @@ -399,6 +399,7 @@ config FRAME_WARN
>>  	default 2048 if GCC_PLUGIN_LATENT_ENTROPY
>>  	default 2048 if PARISC
>>  	default 1536 if (!64BIT && XTENSA)
>> +	default 1280 if KASAN && !64BIT
>>  	default 1024 if !64BIT
>>  	default 2048 if 64BIT
>>  	help
>
> Note this also fixes 61 warnings when
>
>   (GCC && !GCC_PLUGIN_LATENT_ENTROPY)
>
> ... which as Arnd says should not be enabled by default.  We'll
> address that issue once this set has been applied.

Thanks a lot for checking this!

Reviewed-by: Arnd Bergmann <arnd@arndb.de>