[PATCH v4 1/7] kernel/fork: convert vma assignment to a memcpy

Suren Baghdasaryan posted 7 patches 1 year, 9 months ago
[PATCH v4 1/7] kernel/fork: convert vma assignment to a memcpy
Posted by Suren Baghdasaryan 1 year, 9 months ago
Convert vma assignment in vm_area_dup() to a memcpy() to prevent compiler
errors when we add a const modifier to vma->vm_flags.

Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
---
 kernel/fork.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/fork.c b/kernel/fork.c
index 441dcec60aae..9260f975b8f4 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -472,7 +472,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
 		 * orig->shared.rb may be modified concurrently, but the clone
 		 * will be reinitialized.
 		 */
-		*new = data_race(*orig);
+		data_race(memcpy(new, orig, sizeof(*new)));
 		INIT_LIST_HEAD(&new->anon_vma_chain);
 		dup_anon_vma_name(orig, new);
 	}
-- 
2.39.1
Re: [PATCH v4 1/7] kernel/fork: convert vma assignment to a memcpy
Posted by Mike Rapoport 1 year, 9 months ago
On Thu, Jan 26, 2023 at 11:37:46AM -0800, Suren Baghdasaryan wrote:
> Convert vma assignment in vm_area_dup() to a memcpy() to prevent compiler
> errors when we add a const modifier to vma->vm_flags.
> 
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
> Acked-by: Mel Gorman <mgorman@techsingularity.net>

Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>

> ---
>  kernel/fork.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/kernel/fork.c b/kernel/fork.c
> index 441dcec60aae..9260f975b8f4 100644
> --- a/kernel/fork.c
> +++ b/kernel/fork.c
> @@ -472,7 +472,7 @@ struct vm_area_struct *vm_area_dup(struct vm_area_struct *orig)
>  		 * orig->shared.rb may be modified concurrently, but the clone
>  		 * will be reinitialized.
>  		 */
> -		*new = data_race(*orig);
> +		data_race(memcpy(new, orig, sizeof(*new)));
>  		INIT_LIST_HEAD(&new->anon_vma_chain);
>  		dup_anon_vma_name(orig, new);
>  	}
> -- 
> 2.39.1
> 

-- 
Sincerely yours,
Mike.