mmap should return ENOMEM on len overflow rather than EINVAL. Return
EINVAL when len == 0 and ENOMEM when the rounded to a page length is 0.
Found by make check-tcg.

Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Kyle Evans <kevans@FreeBSD.org>
---
 bsd-user/mmap.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/bsd-user/mmap.c b/bsd-user/mmap.c
index 6f33aec58b..f0be3b12cf 100644
--- a/bsd-user/mmap.c
+++ b/bsd-user/mmap.c
@@ -455,11 +455,18 @@ abi_long target_mmap(abi_ulong start, abi_ulong len, int prot,
         goto fail;
     }
 
-    len = TARGET_PAGE_ALIGN(len);
     if (len == 0) {
         errno = EINVAL;
         goto fail;
     }
+
+    /* Check for overflows */
+    len = TARGET_PAGE_ALIGN(len);
+    if (len == 0) {
+        errno = ENOMEM;
+        goto fail;
+    }
+
     real_start = start & qemu_host_page_mask;
     host_offset = offset & qemu_host_page_mask;
 
-- 
2.32.0