On Fri, Jun 30, 2023 at 7:22 AM Richard Henderson <richard.henderson@linaro.org
<mailto: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 <mailto:imp@bsdimp.com>>
Cc: Kyle Evans <kevans@freebsd.org <mailto:kevans@freebsd.org>>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org
<mailto: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))
{
Won't computing end overflow if start is 1<<32 - len? Then subtracting one here would be
too late.