mirror of
https://mirrors.bfsu.edu.cn/git/linux.git
synced 2024-12-03 17:14:14 +08:00
219b47339c
Currently we have a problem with this: 1. i915: create gem object 2. i915: export gem object to prime 3. radeon: import gem object 4. close prime fd 5. radeon: unref object 6. i915: unref object i915 has an imported object reference in its file priv, that isn't cleaned up properly until fd close. The reference gets added at step 2, but at step 6 we don't have enough info to clean it up. The solution is to take a reference on the dma-buf when we export it, and drop the reference when the gem handle goes away. So when we export a dma_buf from a gem object, we keep track of it with the handle, we take a reference to the dma_buf. When we close the handle (i.e. userspace is finished with the buffer), we drop the reference to the dma_buf, and it gets collected. This patch isn't meant to fix any other problem or bikesheds, and it doesn't fix any races with other scenarios. v1.1: move export symbol line back up. v2: okay I had to do a bit more, as the first patch showed a leak on one of my tests, that I found using the dma-buf debugfs support, the problem case is exporting a buffer twice with the same handle, we'd add another export handle for it unnecessarily, however we now fail if we try to export the same object with a different gem handle, however I'm not sure if that is a case I want to support, and I've gotten the code to WARN_ON if we hit something like that. v2.1: rebase this patch, write better commit msg. v3: cleanup error handling, track import vs export in linked list, these two patches were separate previously, but seem to work better like this. v4: danvet is correct, this code is no longer useful, since the buffer better exist, so remove it. v5: always take a reference to the dma buf object, import or export. (Imre Deak contributed this originally) v6: square the circle, remove import vs export tracking now that there is no difference Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch> Cc: stable@vger.kernel.org Signed-off-by: Dave Airlie <airlied@redhat.com> |
||
|---|---|---|
| .. | ||
| acpi | ||
| asm-generic | ||
| clocksource | ||
| crypto | ||
| drm | ||
| keys | ||
| linux | ||
| math-emu | ||
| media | ||
| memory | ||
| misc | ||
| net | ||
| pcmcia | ||
| ras | ||
| rdma | ||
| rxrpc | ||
| scsi | ||
| sound | ||
| target | ||
| trace | ||
| uapi | ||
| video | ||
| xen | ||
| Kbuild | ||