On Fri, Jun 30, 2023 at 7:22 AM Richard Henderson <
richard.hender...@linaro.org> wrote:
> The previous check returned -1 when any page within
> [start, start+len) is unmapped, not when all are unmapped.
>
> Cc: Warner Losh <i...@bsdimp.com>
> Cc: Kyle Evans <kev...@freebsd.org>
> Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
> ---
> bsd-user/mmap.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
> index 565b9f97ed..07b5b8055e 100644
> --- a/bsd-user/mmap.c
> +++ b/bsd-user/mmap.c
> @@ -609,7 +609,7 @@ abi_long target_mmap(abi_ulong start, abi_ulong len,
> int prot,
> }
>
> /* Reject the mapping if any page within the range is mapped */
> - if ((flags & MAP_EXCL) && page_check_range(start, len, 0) < 0) {
> + if ((flags & MAP_EXCL) && !page_check_range_empty(start, end -
> 1)) {
>
Won't computing end overflow if start is 1<<32 - len? Then subtracting one
here would be too late.
Warner
> errno = EINVAL;
> goto fail;
> }
> --
> 2.34.1
>
>
