diff mbox series

[v1,1/5] mm: vmalloc must set pte via arch code

Message ID 20230511125848.78621-2-ryan.roberts@arm.com
State New
Headers
Series [v1,1/5] mm: vmalloc must set pte via arch code |

Commit Message

Ryan Roberts May 11, 2023, 12:58 p.m. UTC 
  It is bad practice to directly set pte entries within a pte table.
Instead all modifications must go through arch-provided helpers such as
set_pte_at() to give the arch code visibility and allow it to validate
(and potentially modify) the operation.

Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 mm/vmalloc.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

Comments

Ryan Roberts May 11, 2023, 1:14 p.m. UTC | #1 
My appologies for the noise: A blank line between Cc and Subject has broken the
subject and grouping in lore.

Please Ignore this, I will resend.


On 11/05/2023 13:58, Ryan Roberts wrote:
> It is bad practice to directly set pte entries within a pte table.
> Instead all modifications must go through arch-provided helpers such as
> set_pte_at() to give the arch code visibility and allow it to validate
> (and potentially modify) the operation.
> 
> Fixes: 3e9a9e256b1e ("mm: add a vmap_pfn function")
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---
>  mm/vmalloc.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/mm/vmalloc.c b/mm/vmalloc.c
> index 9683573f1225..d8d2fe797c55 100644
> --- a/mm/vmalloc.c
> +++ b/mm/vmalloc.c
> @@ -2899,10 +2899,13 @@ struct vmap_pfn_data {
>  static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
>  {
>  	struct vmap_pfn_data *data = private;
> +	pte_t ptent;
>  
>  	if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx])))
>  		return -EINVAL;
> -	*pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
> +
> +	ptent = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
> +	set_pte_at(&init_mm, addr, pte, ptent);
>  	return 0;
>  }
>
diff mbox series

Patch

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 9683573f1225..d8d2fe797c55 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -2899,10 +2899,13 @@  struct vmap_pfn_data {
 static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
 {
 	struct vmap_pfn_data *data = private;
+	pte_t ptent;
 
 	if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx])))
 		return -EINVAL;
-	*pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
+
+	ptent = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot));
+	set_pte_at(&init_mm, addr, pte, ptent);
 	return 0;
 }