[v2] linux-user: mmap range fixes

[PATCH v2 08/24] bsd-user: Use page_check_range_empty for MAP_EXCL

Posted by Richard Henderson 2 years, 7 months ago

The previous check returned -1 when any page within
[start, start+len) is unmapped, not when all are unmapped.

Cc: Warner Losh <imp@bsdimp.com>
Cc: Kyle Evans <kevans@freebsd.org>
Signed-off-by: Richard Henderson <richard.henderson@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)) {
             errno = EINVAL;
             goto fail;
         }
-- 
2.34.1

Re: [PATCH v2 08/24] bsd-user: Use page_check_range_empty for MAP_EXCL

Posted by Warner Losh 2 years, 7 months ago

On Fri, Jul 7, 2023 at 2:41 PM Richard Henderson <
richard.henderson@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 <imp@bsdimp.com>
> Cc: Kyle Evans <kevans@freebsd.org>
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
>

Reviewed-by: Warner Losh <imp@bsdimp.com>

Warner


> ---
>  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)) {
>              errno = EINVAL;
>              goto fail;
>          }
> --
> 2.34.1
>
>