Arm64 defconfig-debug

Arm64 defconfig-debug

[Qian Cai]

Hi there, some general debugging features like kmemleak, KASAN, lockdep,
UBSAN etc help fix many bugs like a microscope. On the other hand, those
features are scatter around and mixed up with more situational debugging
options making them difficult to consume properly.

Since I have been deal with those options on a daily basis for the last
a few years and accumulated the knowledge of their pros and cons, I am
thinking about to create an initial defconfig-debug available inside the
tree, so that it could amplify the general debugging/testing efforts for
arm64 across the broad.

The downside is that this might open a gate for other people to push yet
another subject-specific defconfig, but I don't see anything as
important as general debugging/testing at the moment. Then, there are
two defconfig need to be modified for some common changes, but I think
that is quite trivial to do. We could even create a simple script to
sync if that is not overkill.

Re: Arm64 defconfig-debug

[Will Deacon]

On Wed, Oct 27, 2021 at 03:45:32PM -0400, Qian Cai wrote:
> Hi there, some general debugging features like kmemleak, KASAN, lockdep,
> UBSAN etc help fix many bugs like a microscope. On the other hand, those
> features are scatter around and mixed up with more situational debugging
> options making them difficult to consume properly.
> 
> Since I have been deal with those options on a daily basis for the last
> a few years and accumulated the knowledge of their pros and cons, I am
> thinking about to create an initial defconfig-debug available inside the
> tree, so that it could amplify the general debugging/testing efforts for
> arm64 across the broad.
> 
> The downside is that this might open a gate for other people to push yet
> another subject-specific defconfig, but I don't see anything as
> important as general debugging/testing at the moment. Then, there are
> two defconfig need to be modified for some common changes, but I think
> that is quite trivial to do. We could even create a simple script to
> sync if that is not overkill.

I'm not in favour of adding a whole new debug-flavoured defconfig for arm64,
but you might be able to add some reduced config file containing just the
options you're interested in to kernel/configs/. That said, I'm not sure the
existing files under there are well-maintained at all. The Android ones,
especially, looks like they should just be removed.

Will

Re: Arm64 defconfig-debug

[Qian Cai]

On 10/28/21 3:49 AM, Will Deacon wrote:
> I'm not in favour of adding a whole new debug-flavoured defconfig for arm64,
> but you might be able to add some reduced config file containing just the
> options you're interested in to kernel/configs/. That said, I'm not sure the
> existing files under there are well-maintained at all. The Android ones,
> especially, looks like they should just be removed.

Thanks for the pointer, Will. I'll dig into that direction then.