Re: [PATCH] drm/panthor: Lock XArray when getting entries for heap and VM

[Boris Brezillon <boris.brezillon@collabora.com>]

On Wed, 6 Nov 2024 13:10:37 +0000
Liviu Dudau <liviu.dudau@arm.com> wrote:

> panthor_heap_pool_release() does not take the panthor_heap_pool::lock, so the protection
> is not really there. I could fix panthor_heap_pool_release() and then add a
> lockdep_assert_held() before both calls to xa_load() if you think that's a better
> solution.

Hm, but panthor_heap_pool_release() doesn't release the heap contexts,
it just calls xa_destroy(). If we have objects remaining in the xarray,
they'll be leaked, but that's not a race. BTW, can we make this two
separate patches. I feel like the thing on the vm is an actual fix,
while the second one (adding a helper with a lockdep_assert()) is
safety net that's worth having, but not necessarily something we need
to backport.