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BACKPORT: ANDROID: GKI: dma-buf: Add support to set a destructor on a dma-buf

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dma-buf destructor support is useful as it allows clients an opportunity
to undo any attributes, such as security attributes, they have applied to
the dma-buf's memory.

The destructor is called when the dma-buf is freed, if the destructor
returns an error the dma-buf's exporter release function is not called in
order to ensure that memory which has not been properly cleaned up isn't
returned to the system.

Signed-off-by: Liam Mark <lmark@codeaurora.org>
Signed-off-by: Swathi Sridhar <swatsrid@codeaurora.org>

[surenb: cherry-picked from:
3af4db1543c9 "dma-buf: Add support to set a destructor on a dma-buf"]

Bug: 150611569
Test: build
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Change-Id: I2d435b99fb9b1747bc1b32a4e0d484957614a5a3
Signed-off-by: Jianqun Xu <jay.xu@rock-chips.com>
This commit is contained in:
Liam Mark
2019-02-21 11:56:18 -08:00
committed by Tao Huang
parent 458fe9eb4e
commit 345084a2ed
2 changed files with 43 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files
drivers/dma-buf/dma-buf.c
+10 -1
View File
@@ -81,6 +81,9 @@ static char *dmabuffs_dname(struct dentry *dentry, char *buffer, int buflen)
static void dma_buf_release(struct dentry *dentry)
{
struct dma_buf *dmabuf;
#ifdef CONFIG_NO_GKI
int dtor_ret = 0;
#endif
dmabuf = dentry->d_fsdata;
if (unlikely(!dmabuf))
@@ -99,7 +102,13 @@ static void dma_buf_release(struct dentry *dentry)
BUG_ON(dmabuf->cb_shared.active || dmabuf->cb_excl.active);
dma_buf_stats_teardown(dmabuf);
dmabuf->ops->release(dmabuf);
#ifdef CONFIG_NO_GKI
if (dmabuf->dtor)
dtor_ret = dmabuf->dtor(dmabuf, dmabuf->dtor_data);
if (!dtor_ret)
#endif
dmabuf->ops->release(dmabuf);
if (dmabuf->resv == (struct dma_resv *)&dmabuf[1])
dma_resv_fini(dmabuf->resv);
include/linux/dma-buf.h
+33
View File
@@ -359,6 +359,20 @@ struct dma_buf_ops {
ANDROID_KABI_RESERVE(2);
};
#ifdef CONFIG_NO_GKI
/**
* dma_buf_destructor - dma-buf destructor function
* @dmabuf: [in] pointer to dma-buf
* @dtor_data: [in] destructor data associated with this buffer
*
* The dma-buf destructor which is called when the dma-buf is freed.
*
* If the destructor returns an error the dma-buf's exporter release function
* won't be called.
*/
typedef int (*dma_buf_destructor)(struct dma_buf *dmabuf, void *dtor_data);
#endif
/**
* struct dma_buf - shared buffer object
* @size: size of the buffer
@@ -425,6 +439,10 @@ struct dma_buf {
struct dma_buf *dmabuf;
} *sysfs_entry;
#endif
#ifdef CONFIG_NO_GKI
dma_buf_destructor dtor;
void *dtor_data;
#endif
ANDROID_KABI_RESERVE(1);
ANDROID_KABI_RESERVE(2);
@@ -626,4 +644,19 @@ void dma_buf_vunmap(struct dma_buf *, void *vaddr);
int dma_buf_get_flags(struct dma_buf *dmabuf, unsigned long *flags);
int dma_buf_get_uuid(struct dma_buf *dmabuf, uuid_t *uuid);
#ifdef CONFIG_NO_GKI
/**
* dma_buf_set_destructor - set the dma-buf's destructor
* @dmabuf: [in] pointer to dma-buf
* @dma_buf_destructor [in] the destructor function
* @dtor_data: [in] destructor data associated with this buffer
*/
static inline void dma_buf_set_destructor(struct dma_buf *dmabuf,
dma_buf_destructor dtor,
void *dtor_data)
{
dmabuf->dtor = dtor;
dmabuf->dtor_data = dtor_data;
}
#endif
#endif /* __DMA_BUF_H__ */