[PATCH] uacce: remove uacce_vma_fault

[PATCH] uacce: remove uacce_vma_fault

[Zhangfei Gao]

Fix NULL pointer error if removing uacce's parent module during app's
running. SIGBUS is already reported by do_page_fault, so uacce_vma_fault
is not needed. If providing vma_fault, vmf->page has to be filled as well,
required by __do_fault.

Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>
---
 drivers/misc/uacce/uacce.c | 9 ---------
 1 file changed, 9 deletions(-)

diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
index 107028e..aa91f69 100644
--- a/drivers/misc/uacce/uacce.c
+++ b/drivers/misc/uacce/uacce.c
@@ -179,14 +179,6 @@ static int uacce_fops_release(struct inode *inode, struct file *filep)
 	return 0;
 }
 
-static vm_fault_t uacce_vma_fault(struct vm_fault *vmf)
-{
-	if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
-		return VM_FAULT_SIGBUS;
-
-	return 0;
-}
-
 static void uacce_vma_close(struct vm_area_struct *vma)
 {
 	struct uacce_queue *q = vma->vm_private_data;
@@ -199,7 +191,6 @@ static void uacce_vma_close(struct vm_area_struct *vma)
 }
 
 static const struct vm_operations_struct uacce_vm_ops = {
-	.fault = uacce_vma_fault,
 	.close = uacce_vma_close,
 };
 
-- 
2.7.4

Re: [PATCH] uacce: remove uacce_vma_fault

[Jean-Philippe Brucker]

On Mon, Jun 15, 2020 at 09:55:57PM +0800, Zhangfei Gao wrote:
> Fix NULL pointer error if removing uacce's parent module during app's
> running. SIGBUS is already reported by do_page_fault, so uacce_vma_fault
> is not needed. If providing vma_fault, vmf->page has to be filled as well,
> required by __do_fault.
> 
> Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> Signed-off-by: Zhangfei Gao <zhangfei.gao@linaro.org>

Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

> ---
>  drivers/misc/uacce/uacce.c | 9 ---------
>  1 file changed, 9 deletions(-)
> 
> diff --git a/drivers/misc/uacce/uacce.c b/drivers/misc/uacce/uacce.c
> index 107028e..aa91f69 100644
> --- a/drivers/misc/uacce/uacce.c
> +++ b/drivers/misc/uacce/uacce.c
> @@ -179,14 +179,6 @@ static int uacce_fops_release(struct inode *inode, struct file *filep)
>  	return 0;
>  }
>  
> -static vm_fault_t uacce_vma_fault(struct vm_fault *vmf)
> -{
> -	if (vmf->flags & (FAULT_FLAG_MKWRITE | FAULT_FLAG_WRITE))
> -		return VM_FAULT_SIGBUS;
> -
> -	return 0;
> -}
> -
>  static void uacce_vma_close(struct vm_area_struct *vma)
>  {
>  	struct uacce_queue *q = vma->vm_private_data;
> @@ -199,7 +191,6 @@ static void uacce_vma_close(struct vm_area_struct *vma)
>  }
>  
>  static const struct vm_operations_struct uacce_vm_ops = {
> -	.fault = uacce_vma_fault,
>  	.close = uacce_vma_close,
>  };
>  
> -- 
> 2.7.4
>