[Qemu-devel] [PATCH v2 2/4] tcg: Fix off-by-one in assert in page_set_flags

[Richard Henderson <richard.henderson@linaro.org>]

From: Richard Henderson <rth@twiddle.net>

Most of the users of page_set_flags offset (page, page + len) as
the end points.  One might consider this an error, since the other
users do supply an endpoint as the last byte of the region.

However, the first thing that page_set_flags does is round end UP
to the start of the next page.  Which means computing page + len - 1
is in the end pointless.  Therefore, accept this usage and do not
assert when given the exact size of the vm as the endpoint.

Signed-off-by: Richard Henderson <rth@twiddle.net>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20170708025030.15845-2-rth@twiddle.net>
---
 accel/tcg/translate-all.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c
index 2d1ed06065..ebfc2e7024 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -2090,7 +2090,7 @@ void page_set_flags(target_ulong start, target_ulong end, int flags)
        guest address space.  If this assert fires, it probably indicates
        a missing call to h2g_valid.  */
 #if TARGET_ABI_BITS > L1_MAP_ADDR_SPACE_BITS
-    assert(end < ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS));
+    assert(end <= ((target_ulong)1 << L1_MAP_ADDR_SPACE_BITS));
 #endif
     assert(start < end);
     assert_memory_lock();
-- 
2.13.6