Re: [Qemu-devel] [PATCH 06/10] linux-user: init_guest_commpage: Add a comment about size check

[Laurent Vivier]

Le 28/12/2017 à 19:08, Luke Shumaker a écrit :
> From: Luke Shumaker 
> 
> Signed-off-by: Luke Shumaker 
> ---
>  linux-user/elfload.c | 5 +
>  1 file changed, 5 insertions(+)

Applied to my 'linux-user-for-2.12' branch.

Thanks,
Laurent

Re: [Qemu-devel] [PATCH 06/10] linux-user: init_guest_commpage: Add a comment about size check

[Peter Maydell]

On 28 December 2017 at 18:08, Luke Shumaker  wrote:
> From: Luke Shumaker 
>
> Signed-off-by: Luke Shumaker 
> ---
>  linux-user/elfload.c | 5 +
>  1 file changed, 5 insertions(+)
>
> diff --git a/linux-user/elfload.c b/linux-user/elfload.c
> index 22f2632dfa..b560f5d6fe 100644
> --- a/linux-user/elfload.c
> +++ b/linux-user/elfload.c
> @@ -374,6 +374,11 @@ static int init_guest_commpage(unsigned long guest_base,
>
>  /* If the commpage lies within the already allocated guest space,
>   * then there is no way we can allocate it.
> + *
> + * You may be thinking that that this check is redundant because
> + * we already validated the guest size against MAX_RESERVED_VA;
> + * but if qemu_host_page_mask is unusually large, then
> + * test_page_addr may be lower.
>   */
>  if (test_page_addr >= guest_base
>  && test_page_addr < (guest_base + guest_size)) {
> --

Reviewed-by: Peter Maydell 

thanks
-- PMM

[Qemu-devel] [PATCH 06/10] linux-user: init_guest_commpage: Add a comment about size check

[Luke Shumaker]

From: Luke Shumaker 

Signed-off-by: Luke Shumaker 
---
 linux-user/elfload.c | 5 +
 1 file changed, 5 insertions(+)

diff --git a/linux-user/elfload.c b/linux-user/elfload.c
index 22f2632dfa..b560f5d6fe 100644
--- a/linux-user/elfload.c
+++ b/linux-user/elfload.c
@@ -374,6 +374,11 @@ static int init_guest_commpage(unsigned long guest_base,
 
 /* If the commpage lies within the already allocated guest space,
  * then there is no way we can allocate it.
+ *
+ * You may be thinking that that this check is redundant because
+ * we already validated the guest size against MAX_RESERVED_VA;
+ * but if qemu_host_page_mask is unusually large, then
+ * test_page_addr may be lower.
  */
 if (test_page_addr >= guest_base
 && test_page_addr < (guest_base + guest_size)) {
-- 
2.15.1