bsd-user: Implement msync(2)

Co-authored-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Karim Taha <kariem.taha2.7@gmail.com>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230925182709.4834-15-kariem.taha2.7@gmail.com>

bsd-user/bsd-mem.h

@@ -88,4 +88,15 @@ static inline abi_long do_bsd_mprotect(abi_long arg1, abi_long arg2,
     return get_errno(target_mprotect(arg1, arg2, arg3));
 }
 
+/* msync(2) */
+static inline abi_long do_bsd_msync(abi_long addr, abi_long len, abi_long flags)
+{
+    if (!guest_range_valid_untagged(addr, len)) {
+        /* It seems odd, but POSIX wants this to be ENOMEM */
+        return -TARGET_ENOMEM;
+    }
+
+    return get_errno(msync(g2h_untagged(addr), len, flags));
+}
+
 #endif /* BSD_USER_BSD_MEM_H */