diff mbox series

[20/20] maccess: return -ERANGE when copy_from_kernel_nofault_allowed fails

Message ID 20200519134449.1466624-21-hch@lst.de (mailing list archive)
State Superseded
Headers show
Series [01/20] maccess: unexport probe_kernel_write and probe_user_write | expand

Commit Message

Christoph Hellwig May 19, 2020, 1:44 p.m. UTC
Allow the callers to distinguish a real unmapped address vs a range
that can't be probed.

Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 mm/maccess.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Masami Hiramatsu (Google) May 20, 2020, 11:02 a.m. UTC | #1
On Tue, 19 May 2020 15:44:49 +0200
Christoph Hellwig <hch@lst.de> wrote:

> Allow the callers to distinguish a real unmapped address vs a range
> that can't be probed.
> 
> Suggested-by: Masami Hiramatsu <mhiramat@kernel.org>
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Hi Christoph,

Can you also update the kerneldoc comment too?
Other than that, this looks good to me.

Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>

Thank you!

> ---
>  mm/maccess.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
> 
> diff --git a/mm/maccess.c b/mm/maccess.c
> index 1e7d77656c596..4010d64189d21 100644
> --- a/mm/maccess.c
> +++ b/mm/maccess.c
> @@ -25,7 +25,7 @@ bool __weak copy_from_kernel_nofault_allowed(void *dst, const void *unsafe_src,
>  long copy_from_kernel_nofault(void *dst, const void *src, size_t size)
>  {
>  	if (!copy_from_kernel_nofault_allowed(dst, src, size))
> -		return -EFAULT;
> +		return -ERANGE;
>  
>  	pagefault_disable();
>  	copy_from_kernel_nofault_loop(dst, src, size, u64, Efault);
> @@ -69,7 +69,7 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
>  	if (unlikely(count <= 0))
>  		return 0;
>  	if (!copy_from_kernel_nofault_allowed(dst, unsafe_addr, count))
> -		return -EFAULT;
> +		return -ERANGE;
>  
>  	pagefault_disable();
>  	do {
> @@ -107,7 +107,7 @@ long copy_from_kernel_nofault(void *dst, const void *src, size_t size)
>  	mm_segment_t old_fs = get_fs();
>  
>  	if (!copy_from_kernel_nofault_allowed(dst, src, size))
> -		return -EFAULT;
> +		return -ERANGE;
>  
>  	set_fs(KERNEL_DS);
>  	pagefault_disable();
> @@ -174,7 +174,7 @@ long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
>  	if (unlikely(count <= 0))
>  		return 0;
>  	if (!copy_from_kernel_nofault_allowed(dst, unsafe_addr, count))
> -		return -EFAULT;
> +		return -ERANGE;
>  
>  	set_fs(KERNEL_DS);
>  	pagefault_disable();
> -- 
> 2.26.2
>
Christoph Hellwig May 20, 2020, 4:16 p.m. UTC | #2
On Wed, May 20, 2020 at 08:02:55PM +0900, Masami Hiramatsu wrote:
> Can you also update the kerneldoc comment too?

Sure, done.
diff mbox series

Patch

diff --git a/mm/maccess.c b/mm/maccess.c
index 1e7d77656c596..4010d64189d21 100644
--- a/mm/maccess.c
+++ b/mm/maccess.c
@@ -25,7 +25,7 @@  bool __weak copy_from_kernel_nofault_allowed(void *dst, const void *unsafe_src,
 long copy_from_kernel_nofault(void *dst, const void *src, size_t size)
 {
 	if (!copy_from_kernel_nofault_allowed(dst, src, size))
-		return -EFAULT;
+		return -ERANGE;
 
 	pagefault_disable();
 	copy_from_kernel_nofault_loop(dst, src, size, u64, Efault);
@@ -69,7 +69,7 @@  long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
 	if (unlikely(count <= 0))
 		return 0;
 	if (!copy_from_kernel_nofault_allowed(dst, unsafe_addr, count))
-		return -EFAULT;
+		return -ERANGE;
 
 	pagefault_disable();
 	do {
@@ -107,7 +107,7 @@  long copy_from_kernel_nofault(void *dst, const void *src, size_t size)
 	mm_segment_t old_fs = get_fs();
 
 	if (!copy_from_kernel_nofault_allowed(dst, src, size))
-		return -EFAULT;
+		return -ERANGE;
 
 	set_fs(KERNEL_DS);
 	pagefault_disable();
@@ -174,7 +174,7 @@  long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr, long count)
 	if (unlikely(count <= 0))
 		return 0;
 	if (!copy_from_kernel_nofault_allowed(dst, unsafe_addr, count))
-		return -EFAULT;
+		return -ERANGE;
 
 	set_fs(KERNEL_DS);
 	pagefault_disable();