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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: Richard Henderson <rth@twiddle.net>, patches@linaro.org
Subject: [Qemu-devel] [RFC 2/3] tcg: Avoid stores to unaligned addresses
Date: Fri, 28 Mar 2014 15:29:47 +0000	[thread overview]
Message-ID: <1396020588-2137-3-git-send-email-peter.maydell@linaro.org> (raw)
In-Reply-To: <1396020588-2137-1-git-send-email-peter.maydell@linaro.org>

Avoid stores to unaligned addresses in TCG code generation, by using the
usual memcpy() approach. (Using bswap.h would drag a lot of QEMU baggage
into TCG, so it's simpler just to do direct memcpy() here.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
 tcg/tcg.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tcg/tcg.c b/tcg/tcg.c
index f1e0763..60f06c5 100644
--- a/tcg/tcg.c
+++ b/tcg/tcg.c
@@ -125,21 +125,21 @@ static inline void tcg_out8(TCGContext *s, uint8_t v)
 static inline void tcg_out16(TCGContext *s, uint16_t v)
 {
     uint8_t *p = s->code_ptr;
-    *(uint16_t *)p = v;
+    memcpy(p, &v, sizeof(v));
     s->code_ptr = p + 2;
 }
 
 static inline void tcg_out32(TCGContext *s, uint32_t v)
 {
     uint8_t *p = s->code_ptr;
-    *(uint32_t *)p = v;
+    memcpy(p, &v, sizeof(v));
     s->code_ptr = p + 4;
 }
 
 static inline void tcg_out64(TCGContext *s, uint64_t v)
 {
     uint8_t *p = s->code_ptr;
-    *(uint64_t *)p = v;
+    memcpy(p, &v, sizeof(v));
     s->code_ptr = p + 8;
 }
 
-- 
1.9.0

  parent reply	other threads:[~2014-03-28 15:56 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-03-28 15:29 [Qemu-devel] [RFC 0/3] tcg: Avoid undefined behaviour on unaligned stores Peter Maydell
2014-03-28 15:29 ` [Qemu-devel] [RFC 1/3] exec-all.h: Use stl_p to avoid undefined behaviour patching x86 jumps Peter Maydell
2014-03-28 15:29 ` Peter Maydell [this message]
2014-03-28 16:00   ` [Qemu-devel] [RFC 2/3] tcg: Avoid stores to unaligned addresses Andreas Färber
2014-03-28 15:29 ` [Qemu-devel] [RFC 3/3] tcg: Avoid undefined behaviour patching code at " Peter Maydell
2014-03-28 18:06 ` [Qemu-devel] [RFC 0/3] tcg: Avoid undefined behaviour on unaligned stores Richard Henderson
2014-03-28 18:18   ` Peter Maydell
2014-03-28 18:48     ` Richard Henderson

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