From: Jim Meyering <meyering@redhat.com>
Date: Mon, 26 May 2008 14:25:28 +0000 (+0200)
Subject: avoid unaligned access errors, e.g., on sparc
X-Git-Tag: v0.1~7342
X-Git-Url: http://erislabs.net/gitweb/?a=commitdiff_plain;h=e341e7caaea9a3fd5f311195b023af8d280944fa;p=gnulib.git

avoid unaligned access errors, e.g., on sparc

* lib/sha512.c (sha512_conclude_ctx): Use set_uint64 rather than
direct access through a possibly-unaligned uint64* pointer.
* lib/sha256.c (sha256_conclude_ctx): Use set_uint32 rather than
direct access through a possibly-unaligned uint32* pointer.
Prompted by this patch from Tom "spot" Callaway:
http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/13638
---

diff --git a/ChangeLog b/ChangeLog
index 32655cb6b..9aea4e6b3 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,13 @@
 2008-05-26  Jim Meyering  <meyering@redhat.com>
 
+	avoid unaligned access errors, e.g., on sparc
+	* lib/sha512.c (sha512_conclude_ctx): Use set_uint64 rather than
+	direct access through a possibly-unaligned uint64* pointer.
+	* lib/sha256.c (sha256_conclude_ctx): Use set_uint32 rather than
+	direct access through a possibly-unaligned uint32* pointer.
+	Prompted by this patch from Tom "spot" Callaway:
+	http://thread.gmane.org/gmane.comp.gnu.coreutils.bugs/13638
+
 	sha512.c: fix typo in comment
 	* lib/sha512.c (sha512_conclude_ctx): Length is 128-bit, not 64-bit.
 
diff --git a/lib/sha256.c b/lib/sha256.c
index 4a632c9fb..a1362caec 100644
--- a/lib/sha256.c
+++ b/lib/sha256.c
@@ -134,9 +134,13 @@ sha256_conclude_ctx (struct sha256_ctx *ctx)
   if (ctx->total[0] < bytes)
     ++ctx->total[1];
 
-  /* Put the 64-bit file length in *bits* at the end of the buffer.  */
-  ctx->buffer[size - 2] = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29));
-  ctx->buffer[size - 1] = SWAP (ctx->total[0] << 3);
+  /* Put the 64-bit file length in *bits* at the end of the buffer.
+     Use set_uint32 rather than a simple assignment, to avoid risk of
+     unaligned access.  */
+  set_uint32 ((char *) &ctx->buffer[size - 2],
+	      SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)));
+  set_uint32 ((char *) &ctx->buffer[size - 1],
+	      SWAP (ctx->total[0] << 3));
 
   memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 4 - bytes);
 
diff --git a/lib/sha512.c b/lib/sha512.c
index 66cfaa9bf..261a7bb02 100644
--- a/lib/sha512.c
+++ b/lib/sha512.c
@@ -141,10 +141,14 @@ sha512_conclude_ctx (struct sha512_ctx *ctx)
   if (u64lt (ctx->total[0], u64lo (bytes)))
     ctx->total[1] = u64plus (ctx->total[1], u64lo (1));
 
-  /* Put the 128-bit file length in *bits* at the end of the buffer.  */
-  ctx->buffer[size - 2] = SWAP (u64or (u64shl (ctx->total[1], 3),
-				       u64shr (ctx->total[0], 61)));
-  ctx->buffer[size - 1] = SWAP (u64shl (ctx->total[0], 3));
+  /* Put the 128-bit file length in *bits* at the end of the buffer.
+     Use set_uint64 rather than a simple assignment, to avoid risk of
+     unaligned access.  */
+  set_uint64 ((char *) &ctx->buffer[size - 2],
+	      SWAP (u64or (u64shl (ctx->total[1], 3),
+			   u64shr (ctx->total[0], 61))));
+  set_uint64 ((char *) &ctx->buffer[size - 1],
+	      SWAP (u64shl (ctx->total[0], 3)));
 
   memcpy (&((char *) ctx->buffer)[bytes], fillbuf, (size - 2) * 8 - bytes);