2020-06-15 13:57:19

by zhangfei

Subject: [PATCH] uacce: remove uacce_vma_fault

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 <[email protected]>
Signed-off-by: Zhangfei Gao <[email protected]>
---
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

2020-06-17 09:34:07

by Jean-Philippe Brucker

Subject: Re: [PATCH] uacce: remove uacce_vma_fault

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 <[email protected]>
> Signed-off-by: Zhangfei Gao <[email protected]>

Reviewed-by: Jean-Philippe Brucker <[email protected]>

> ---
> 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
>