Re: [PATCH] dma-buf: add reference counting for exporter module
Hi Tomasz, On 8 August 2012 19:36, Daniel Vetter wrote: > On Wed, Aug 08, 2012 at 03:53:10PM +0200, Tomasz Stanislawski wrote: >> Hi Laurent, >> >> On 08/08/2012 03:35 PM, Laurent Pinchart wrote: >> > Hi Tomasz, >> > >> > Thanks for the patch. Thanks for the patch; may I ask you to split it into 2 patches (1 dma-buf and 1 drm) and submit? That ways, either Dave or I can take the patches for either pull request. With that, please feel free to add my Acked-by as well. >> > >> > On Wednesday 08 August 2012 12:17:41 Tomasz Stanislawski wrote: >> >> This patch adds reference counting on a module that exports dma-buf and >> >> implements its operations. This prevents the module from being unloaded >> >> while DMABUF file is in use. >> >> >> >> Signed-off-by: Tomasz Stanislawski >> >> --- >> >> Documentation/dma-buf-sharing.txt |3 ++- >> >> drivers/base/dma-buf.c | 10 +- >> >> drivers/gpu/drm/exynos/exynos_drm_dmabuf.c |1 + >> >> drivers/gpu/drm/i915/i915_gem_dmabuf.c |1 + >> >> drivers/gpu/drm/nouveau/nouveau_prime.c|1 + >> >> drivers/gpu/drm/radeon/radeon_prime.c |1 + >> >> drivers/staging/omapdrm/omap_gem_dmabuf.c |1 + >> >> include/linux/dma-buf.h|2 ++ >> >> 8 files changed, 18 insertions(+), 2 deletions(-) >> >> >> [snip] >> >> >> @@ -96,6 +98,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct >> >> dma_buf_ops *ops, struct file *file; >> >> >> >>if (WARN_ON(!priv || !ops >> >> +|| !ops->owner >> >> Thank you for spotting this. >> I didn'y know that try_get_module returned true is module was NULL. >> >> BTW. Is it worth to add ".owner = THIS_MODULE," to all dma_buf >> exporters in this patch? > > Yeah, I think that makes sense. Otherwise it might get lost somewhere, > i.e. you can smash my Ack on this. > -Daniel > -- > Daniel Vetter > Mail: dan...@ffwll.ch > Mobile: +41 (0)79 365 57 48 -- Thanks and regards, Sumit Semwal. -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] dma-buf: add reference counting for exporter module
On Wed, Aug 08, 2012 at 03:53:10PM +0200, Tomasz Stanislawski wrote: > Hi Laurent, > > On 08/08/2012 03:35 PM, Laurent Pinchart wrote: > > Hi Tomasz, > > > > Thanks for the patch. > > > > On Wednesday 08 August 2012 12:17:41 Tomasz Stanislawski wrote: > >> This patch adds reference counting on a module that exports dma-buf and > >> implements its operations. This prevents the module from being unloaded > >> while DMABUF file is in use. > >> > >> Signed-off-by: Tomasz Stanislawski > >> --- > >> Documentation/dma-buf-sharing.txt |3 ++- > >> drivers/base/dma-buf.c | 10 +- > >> drivers/gpu/drm/exynos/exynos_drm_dmabuf.c |1 + > >> drivers/gpu/drm/i915/i915_gem_dmabuf.c |1 + > >> drivers/gpu/drm/nouveau/nouveau_prime.c|1 + > >> drivers/gpu/drm/radeon/radeon_prime.c |1 + > >> drivers/staging/omapdrm/omap_gem_dmabuf.c |1 + > >> include/linux/dma-buf.h|2 ++ > >> 8 files changed, 18 insertions(+), 2 deletions(-) > >> > [snip] > > >> @@ -96,6 +98,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct > >> dma_buf_ops *ops, struct file *file; > >> > >>if (WARN_ON(!priv || !ops > >> +|| !ops->owner > > Thank you for spotting this. > I didn'y know that try_get_module returned true is module was NULL. > > BTW. Is it worth to add ".owner = THIS_MODULE," to all dma_buf > exporters in this patch? Yeah, I think that makes sense. Otherwise it might get lost somewhere, i.e. you can smash my Ack on this. -Daniel -- Daniel Vetter Mail: dan...@ffwll.ch Mobile: +41 (0)79 365 57 48 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] dma-buf: add reference counting for exporter module
Hi Laurent, On 08/08/2012 03:35 PM, Laurent Pinchart wrote: > Hi Tomasz, > > Thanks for the patch. > > On Wednesday 08 August 2012 12:17:41 Tomasz Stanislawski wrote: >> This patch adds reference counting on a module that exports dma-buf and >> implements its operations. This prevents the module from being unloaded >> while DMABUF file is in use. >> >> Signed-off-by: Tomasz Stanislawski >> --- >> Documentation/dma-buf-sharing.txt |3 ++- >> drivers/base/dma-buf.c | 10 +- >> drivers/gpu/drm/exynos/exynos_drm_dmabuf.c |1 + >> drivers/gpu/drm/i915/i915_gem_dmabuf.c |1 + >> drivers/gpu/drm/nouveau/nouveau_prime.c|1 + >> drivers/gpu/drm/radeon/radeon_prime.c |1 + >> drivers/staging/omapdrm/omap_gem_dmabuf.c |1 + >> include/linux/dma-buf.h|2 ++ >> 8 files changed, 18 insertions(+), 2 deletions(-) >> [snip] >> @@ -96,6 +98,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct >> dma_buf_ops *ops, struct file *file; >> >> if (WARN_ON(!priv || !ops >> + || !ops->owner Thank you for spotting this. I didn'y know that try_get_module returned true is module was NULL. BTW. Is it worth to add ".owner = THIS_MODULE," to all dma_buf exporters in this patch? Regards, Tomasz Stanislawski > > THIS_MODULE is defined as ((struct module *)0) when the driver is built-in, > this check should thus be removed. > >>|| !ops->map_dma_buf >>|| !ops->unmap_dma_buf >>|| !ops->release >> -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH] dma-buf: add reference counting for exporter module
Hi Tomasz,
Thanks for the patch.
On Wednesday 08 August 2012 12:17:41 Tomasz Stanislawski wrote:
> This patch adds reference counting on a module that exports dma-buf and
> implements its operations. This prevents the module from being unloaded
> while DMABUF file is in use.
>
> Signed-off-by: Tomasz Stanislawski
> ---
> Documentation/dma-buf-sharing.txt |3 ++-
> drivers/base/dma-buf.c | 10 +-
> drivers/gpu/drm/exynos/exynos_drm_dmabuf.c |1 +
> drivers/gpu/drm/i915/i915_gem_dmabuf.c |1 +
> drivers/gpu/drm/nouveau/nouveau_prime.c|1 +
> drivers/gpu/drm/radeon/radeon_prime.c |1 +
> drivers/staging/omapdrm/omap_gem_dmabuf.c |1 +
> include/linux/dma-buf.h|2 ++
> 8 files changed, 18 insertions(+), 2 deletions(-)
>
> diff --git a/Documentation/dma-buf-sharing.txt
> b/Documentation/dma-buf-sharing.txt index ad86fb8..2613057 100644
> --- a/Documentation/dma-buf-sharing.txt
> +++ b/Documentation/dma-buf-sharing.txt
> @@ -49,7 +49,8 @@ The dma_buf buffer sharing API usage contains the
> following steps: The buffer exporter announces its wish to export a buffer.
> In this, it connects its own private buffer data, provides implementation
> for operations that can be performed on the exported dma_buf, and flags for
> the file
> - associated with this buffer.
> + associated with this buffer. The operations structure has owner field.
> + You should initialize this to THIS_MODULE in most cases.
>
> Interface:
>struct dma_buf *dma_buf_export(void *priv, struct dma_buf_ops *ops,
> diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
> index c30f3e1..d14b2f5 100644
> --- a/drivers/base/dma-buf.c
> +++ b/drivers/base/dma-buf.c
> @@ -27,6 +27,7 @@
> #include
> #include
> #include
> +#include
>
> static inline int is_dma_buf_file(struct file *);
>
> @@ -40,6 +41,7 @@ static int dma_buf_release(struct inode *inode, struct
> file *file) dmabuf = file->private_data;
>
> dmabuf->ops->release(dmabuf);
> + module_put(dmabuf->ops->owner);
> kfree(dmabuf);
> return 0;
> }
> @@ -96,6 +98,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct
> dma_buf_ops *ops, struct file *file;
>
> if (WARN_ON(!priv || !ops
> + || !ops->owner
THIS_MODULE is defined as ((struct module *)0) when the driver is built-in,
this check should thus be removed.
> || !ops->map_dma_buf
> || !ops->unmap_dma_buf
> || !ops->release
>
> @@ -105,9 +108,14 @@ struct dma_buf *dma_buf_export(void *priv, const struct
> dma_buf_ops *ops, return ERR_PTR(-EINVAL);
> }
>
> + if (!try_module_get(ops->owner))
> + return ERR_PTR(-ENOENT);
> +
> dmabuf = kzalloc(sizeof(struct dma_buf), GFP_KERNEL);
> - if (dmabuf == NULL)
> + if (dmabuf == NULL) {
> + module_put(ops->owner);
> return ERR_PTR(-ENOMEM);
> + }
>
> dmabuf->priv = priv;
> dmabuf->ops = ops;
> diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
> b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c index 613bf8a..cf3bc6d 100644
> --- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
> +++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
> @@ -164,6 +164,7 @@ static void exynos_gem_dmabuf_kunmap(struct dma_buf
> *dma_buf, }
>
> static struct dma_buf_ops exynos_dmabuf_ops = {
> + .owner = THIS_MODULE,
> .map_dma_buf= exynos_gem_map_dma_buf,
> .unmap_dma_buf = exynos_gem_unmap_dma_buf,
> .kmap = exynos_gem_dmabuf_kmap,
> diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> b/drivers/gpu/drm/i915/i915_gem_dmabuf.c index aa308e1..07ff03b 100644
> --- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> +++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
> @@ -152,6 +152,7 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf,
> struct vm_area_struct * }
>
> static const struct dma_buf_ops i915_dmabuf_ops = {
> + .owner = THIS_MODULE,
> .map_dma_buf = i915_gem_map_dma_buf,
> .unmap_dma_buf = i915_gem_unmap_dma_buf,
> .release = i915_gem_dmabuf_release,
> diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c
> b/drivers/gpu/drm/nouveau/nouveau_prime.c index a25cf2c..8605033 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_prime.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
> @@ -127,6 +127,7 @@ static void nouveau_gem_prime_vunmap(struct dma_buf
> *dma_buf, void *vaddr) }
>
> static const struct dma_buf_ops nouveau_dmabuf_ops = {
> + .owner = THIS_MODULE,
> .map_dma_buf = nouveau_gem_map_dma_buf,
> .unmap_dma_buf = nouveau_gem_unmap_dma_buf,
> .release = nouveau_gem_dmabuf_release,
> diff --git a/drivers/gpu/drm/radeon/radeon_prime.c
> b/drivers/gpu/drm/radeon/radeon_prime.c index 6bef46a..4061fd3 100644
> --- a/drivers/gpu/drm/radeon/radeon_prime.c
> +++ b/driv
[PATCH] dma-buf: add reference counting for exporter module
This patch adds reference counting on a module that exports dma-buf and
implements its operations. This prevents the module from being unloaded while
DMABUF file is in use.
Signed-off-by: Tomasz Stanislawski
---
Documentation/dma-buf-sharing.txt |3 ++-
drivers/base/dma-buf.c | 10 +-
drivers/gpu/drm/exynos/exynos_drm_dmabuf.c |1 +
drivers/gpu/drm/i915/i915_gem_dmabuf.c |1 +
drivers/gpu/drm/nouveau/nouveau_prime.c|1 +
drivers/gpu/drm/radeon/radeon_prime.c |1 +
drivers/staging/omapdrm/omap_gem_dmabuf.c |1 +
include/linux/dma-buf.h|2 ++
8 files changed, 18 insertions(+), 2 deletions(-)
diff --git a/Documentation/dma-buf-sharing.txt
b/Documentation/dma-buf-sharing.txt
index ad86fb8..2613057 100644
--- a/Documentation/dma-buf-sharing.txt
+++ b/Documentation/dma-buf-sharing.txt
@@ -49,7 +49,8 @@ The dma_buf buffer sharing API usage contains the following
steps:
The buffer exporter announces its wish to export a buffer. In this, it
connects its own private buffer data, provides implementation for operations
that can be performed on the exported dma_buf, and flags for the file
- associated with this buffer.
+ associated with this buffer. The operations structure has owner field.
+ You should initialize this to THIS_MODULE in most cases.
Interface:
struct dma_buf *dma_buf_export(void *priv, struct dma_buf_ops *ops,
diff --git a/drivers/base/dma-buf.c b/drivers/base/dma-buf.c
index c30f3e1..d14b2f5 100644
--- a/drivers/base/dma-buf.c
+++ b/drivers/base/dma-buf.c
@@ -27,6 +27,7 @@
#include
#include
#include
+#include
static inline int is_dma_buf_file(struct file *);
@@ -40,6 +41,7 @@ static int dma_buf_release(struct inode *inode, struct file
*file)
dmabuf = file->private_data;
dmabuf->ops->release(dmabuf);
+ module_put(dmabuf->ops->owner);
kfree(dmabuf);
return 0;
}
@@ -96,6 +98,7 @@ struct dma_buf *dma_buf_export(void *priv, const struct
dma_buf_ops *ops,
struct file *file;
if (WARN_ON(!priv || !ops
+ || !ops->owner
|| !ops->map_dma_buf
|| !ops->unmap_dma_buf
|| !ops->release
@@ -105,9 +108,14 @@ struct dma_buf *dma_buf_export(void *priv, const struct
dma_buf_ops *ops,
return ERR_PTR(-EINVAL);
}
+ if (!try_module_get(ops->owner))
+ return ERR_PTR(-ENOENT);
+
dmabuf = kzalloc(sizeof(struct dma_buf), GFP_KERNEL);
- if (dmabuf == NULL)
+ if (dmabuf == NULL) {
+ module_put(ops->owner);
return ERR_PTR(-ENOMEM);
+ }
dmabuf->priv = priv;
dmabuf->ops = ops;
diff --git a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
index 613bf8a..cf3bc6d 100644
--- a/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
+++ b/drivers/gpu/drm/exynos/exynos_drm_dmabuf.c
@@ -164,6 +164,7 @@ static void exynos_gem_dmabuf_kunmap(struct dma_buf
*dma_buf,
}
static struct dma_buf_ops exynos_dmabuf_ops = {
+ .owner = THIS_MODULE,
.map_dma_buf= exynos_gem_map_dma_buf,
.unmap_dma_buf = exynos_gem_unmap_dma_buf,
.kmap = exynos_gem_dmabuf_kmap,
diff --git a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
index aa308e1..07ff03b 100644
--- a/drivers/gpu/drm/i915/i915_gem_dmabuf.c
+++ b/drivers/gpu/drm/i915/i915_gem_dmabuf.c
@@ -152,6 +152,7 @@ static int i915_gem_dmabuf_mmap(struct dma_buf *dma_buf,
struct vm_area_struct *
}
static const struct dma_buf_ops i915_dmabuf_ops = {
+ .owner = THIS_MODULE,
.map_dma_buf = i915_gem_map_dma_buf,
.unmap_dma_buf = i915_gem_unmap_dma_buf,
.release = i915_gem_dmabuf_release,
diff --git a/drivers/gpu/drm/nouveau/nouveau_prime.c
b/drivers/gpu/drm/nouveau/nouveau_prime.c
index a25cf2c..8605033 100644
--- a/drivers/gpu/drm/nouveau/nouveau_prime.c
+++ b/drivers/gpu/drm/nouveau/nouveau_prime.c
@@ -127,6 +127,7 @@ static void nouveau_gem_prime_vunmap(struct dma_buf
*dma_buf, void *vaddr)
}
static const struct dma_buf_ops nouveau_dmabuf_ops = {
+ .owner = THIS_MODULE,
.map_dma_buf = nouveau_gem_map_dma_buf,
.unmap_dma_buf = nouveau_gem_unmap_dma_buf,
.release = nouveau_gem_dmabuf_release,
diff --git a/drivers/gpu/drm/radeon/radeon_prime.c
b/drivers/gpu/drm/radeon/radeon_prime.c
index 6bef46a..4061fd3 100644
--- a/drivers/gpu/drm/radeon/radeon_prime.c
+++ b/drivers/gpu/drm/radeon/radeon_prime.c
@@ -127,6 +127,7 @@ static void radeon_gem_prime_vunmap(struct dma_buf
*dma_buf, void *vaddr)
mutex_unlock(&dev->struct_mutex);
}
const static struct dma_buf_ops radeon_dmabuf_ops = {
+ .owner = THIS_MODULE,
.map_dma_buf = radeon_gem_map_dma_buf,
.unmap_d
