Re: [PATCH v2 3/9] include/exec: Replace reserved_va with max_reserved_va

[Philippe Mathieu-Daudé]

On 17/3/23 16:54, Richard Henderson wrote:
> In addition to the rename, change the semantics to be the
> last byte of the guest va, rather than the following byte.
> This avoids some overflow conditions.
>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> ---
>   include/exec/cpu-all.h      | 11 ++++++++++-
>   linux-user/arm/target_cpu.h |  2 +-
>   bsd-user/main.c             | 10 +++-------
>   bsd-user/mmap.c             |  4 ++--
>   linux-user/elfload.c        | 21 +++++++++++----------
>   linux-user/main.c           | 27 +++++++++++++--------------
>   linux-user/mmap.c           |  4 ++--
>   7 files changed, 42 insertions(+), 37 deletions(-)


> diff --git a/linux-user/mmap.c b/linux-user/mmap.c
> index 28135c9e6a..cf14930c30 100644
> --- a/linux-user/mmap.c
> +++ b/linux-user/mmap.c
> @@ -283,7 +283,7 @@ static abi_ulong mmap_find_vma_reserved(abi_ulong start, 
> abi_ulong size,
>       end_addr = start + size;
>       if (start > reserved_va - size) {
>           /* Start at the top of the address space.  */
> -        end_addr = ((reserved_va - size) & -align) + size;
> +        end_addr = ((reserved_va + 1 - size) & -align) + size;
>           looped = true;
>       }
>   
> @@ -297,7 +297,7 @@ static abi_ulong mmap_find_vma_reserved(abi_ulong start, abi_ulong size,
>                   return (abi_ulong)-1;
>               }
>               /* Re-start at the top of the address space.  */
> -            addr = end_addr = ((reserved_va - size) & -align) + size;
> +            addr = end_addr = ((reserved_va + 1 - size) & -align) + size;

Possible follow-up cleanup:

  addr = end_addr = ROUND_DOWN(reserved_va + 1 - size, align) + size;

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Better with another R-b on top ;)