On 11/30/21 13:42, Christian König wrote:
Am 30.11.21 um 13:31 schrieb Thomas Hellström:
[SNIP]
Other than that, I didn't investigate the nesting fails enough to
say I can accurately review this. :)
Basically the problem is that within enable_signaling() which is
called with the dma_fence lock held, we take the dma_fence lock of
another fence. If that other fence is a dma_fence_array, or a
dma_fence_chain which in turn tries to lock a dma_fence_array we hit
a splat.
Yeah, I already thought that you constructed something like that.
You get the splat because what you do here is illegal, you can't mix
dma_fence_array and dma_fence_chain like this or you can end up in a
stack corruption.
Hmm. Ok, so what is the stack corruption, is it that the
enable_signaling() will end up with endless recursion? If so, wouldn't
it be more usable we break that recursion chain and allow a more general
use?
Also what are the mixing rules between these? Never use a
dma-fence-chain as one of the array fences and never use a
dma-fence-array as a dma-fence-chain fence?
/Thomas
Regards,
Christian.
But I'll update the commit message with a typical splat.
/Thomas
