Re: [PATCH 5.15 000/245] 5.15.150-rc1 review

From: Greg Kroah-Hartman
Date: Thu Feb 29 2024 - 13:42:13 EST


On Thu, Feb 29, 2024 at 10:15:49AM -0800, Guenter Roeck wrote:
> On 2/27/24 05:23, Greg Kroah-Hartman wrote:
> > This is the start of the stable review cycle for the 5.15.150 release.
> > There are 245 patches in this series, all will be posted as a response
> > to this one. If anyone has any issues with these being applied, please
> > let me know.
> >
> > Responses should be made by Thu, 29 Feb 2024 13:15:36 +0000.
> > Anything received after that time might be too late.
> >
>
> $ git grep dma_fence_allocate_private_stub
> drivers/dma-buf/dma-fence-unwrap.c: return dma_fence_allocate_private_stub(timestamp);
> ^^^^^^^^^
> drivers/dma-buf/dma-fence-unwrap.c: tmp = dma_fence_allocate_private_stub(ktime_get());
> ^^^^^^^^^^^
> drivers/dma-buf/dma-fence.c: * dma_fence_allocate_private_stub - return a private, signaled fence
> drivers/dma-buf/dma-fence.c:struct dma_fence *dma_fence_allocate_private_stub(void)
> ^^^^
> drivers/dma-buf/dma-fence.c:EXPORT_SYMBOL(dma_fence_allocate_private_stub);
> drivers/gpu/drm/drm_syncobj.c: struct dma_fence *fence = dma_fence_allocate_private_stub();
> include/linux/dma-fence.h:struct dma_fence *dma_fence_allocate_private_stub(void);
> ^^^^

How is any of this building then? Does no one actually use
dma-fence-unwrap.c?

> This was introduced with commit 4e82b9c11d3cd ("dma-buf: add dma_fence_timestamp helper") in
> v5.15.149. The additional parameter to dma_fence_allocate_private_stub() was introduced in the
> upstream kernel with commit f781f661e8c99 ("dma-buf: keep the signaling time of merged fences
> v3") which is missing in v5.15.y.

f781f661e8c99 still uses an option to dma_fence_allocate_private_stub():
- return dma_fence_get_stub();
+ return dma_fence_allocate_private_stub(timestamp);

So backporting that will continue the breakage, right?

confused,

greg k-h