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From: Richard Henderson <rth@twiddle.net>
To: qemu-devel@nongnu.org
Cc: riku.voipio@iki.fi, laurent@vivier.eu, qemu-arm@nongnu.org,
	aurelien@aurel32.net
Subject: [Qemu-devel] [PATCH 1/3] tcg: Fix off-by-one in assert in page_set_flags
Date: Fri,  7 Jul 2017 16:50:28 -1000	[thread overview]
Message-ID: <20170708025030.15845-2-rth@twiddle.net> (raw)
In-Reply-To: <20170708025030.15845-1-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>
---
 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 dfb9f0d..57578a4 100644
--- a/accel/tcg/translate-all.c
+++ b/accel/tcg/translate-all.c
@@ -2068,7 +2068,7 @@ 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();
-- 
2.9.4

  reply	other threads:[~2017-07-08  2:50 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-07-08  2:50 [Qemu-devel] [PATCH 0/3] linux-user fixes for va mapping Richard Henderson
2017-07-08  2:50 ` Richard Henderson [this message]
2017-07-08 17:10   ` [Qemu-devel] [Qemu-arm] [PATCH 1/3] tcg: Fix off-by-one in assert in page_set_flags Philippe Mathieu-Daudé
2017-07-08  2:50 ` [Qemu-devel] [PATCH 2/3] linux-user: Tidy and enforce reserved_va initialization Richard Henderson
2017-10-03 16:24   ` Peter Maydell
2017-10-05 13:48     ` Richard Henderson
2017-07-08  2:50 ` [Qemu-devel] [PATCH 3/3] linux-user/sh4: Reduce TARGET_VIRT_ADDR_SPACE_BITS to 31 Richard Henderson
2017-07-08 17:12   ` [Qemu-devel] [Qemu-arm] " Philippe Mathieu-Daudé

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