diff options
Diffstat (limited to 'sys-devel/prelink/files/prelink-20130503-libiberty-md5.patch')
| -rw-r--r-- | sys-devel/prelink/files/prelink-20130503-libiberty-md5.patch | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/sys-devel/prelink/files/prelink-20130503-libiberty-md5.patch b/sys-devel/prelink/files/prelink-20130503-libiberty-md5.patch new file mode 100644 index 000000000000..36b8bcecb312 --- /dev/null +++ b/sys-devel/prelink/files/prelink-20130503-libiberty-md5.patch @@ -0,0 +1,61 @@ +From 8eeb9da6d017761037bf757780ea544dfeabbad8 Mon Sep 17 00:00:00 2001 +From: Mike Frysinger <vapier@gentoo.org> +Date: Tue, 31 Jul 2012 09:02:35 +0000 +Subject: [PATCH] libiberty/md5: fix strict alias warnings +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +Current libiberty md5 code triggers these warnings with gcc-4.7.1 for me: + +libiberty/md5.c: In function âmd5_finish_ctxâ: +libiberty/md5.c:117:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] +libiberty/md5.c:118:3: warning: dereferencing type-punned pointer will break strict-aliasing rules [-Wstrict-aliasing] + +The change below fixes things for me. The optimized output (-O2) is the same +before/after my change on x86_64-linux. I imagine it'll be the same for most +targets. It seems simpler than using a union on the md5_ctx buffer since these +are the only two locations in the code where this occurs. +--- + libiberty/ChangeLog | 5 +++++ + libiberty/md5.c | 12 ++++++++---- + 2 files changed, 13 insertions(+), 4 deletions(-) + +2012-07-31 Mike Frysinger <vapier@gentoo.org> + + * md5.c (md5_finish_ctx): Declare swap_bytes. Assign SWAP() output + to swap_bytes, and then call memcpy to move it to ctx->buffer. + +diff --git a/libiberty/md5.c b/libiberty/md5.c +index 0db8fc8..8cc0cb5 100644 +--- a/src/md5.c ++++ b/src/md5.c +@@ -103,6 +103,7 @@ md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) + { + /* Take yet unprocessed bytes into account. */ + md5_uint32 bytes = ctx->buflen; ++ md5_uint32 swap_bytes; + size_t pad; + + /* Now count remaining bytes. */ +@@ -113,10 +114,13 @@ md5_finish_ctx (struct md5_ctx *ctx, void *resbuf) + pad = bytes >= 56 ? 64 + 56 - bytes : 56 - bytes; + memcpy (&ctx->buffer[bytes], fillbuf, pad); + +- /* Put the 64-bit file length in *bits* at the end of the buffer. */ +- *(md5_uint32 *) &ctx->buffer[bytes + pad] = SWAP (ctx->total[0] << 3); +- *(md5_uint32 *) &ctx->buffer[bytes + pad + 4] = SWAP ((ctx->total[1] << 3) | +- (ctx->total[0] >> 29)); ++ /* Put the 64-bit file length in *bits* at the end of the buffer. ++ Use memcpy to avoid aliasing problems. On most systems, this ++ will be optimized away to the same code. */ ++ swap_bytes = SWAP (ctx->total[0] << 3); ++ memcpy (&ctx->buffer[bytes + pad], &swap_bytes, sizeof (swap_bytes)); ++ swap_bytes = SWAP ((ctx->total[1] << 3) | (ctx->total[0] >> 29)); ++ memcpy (&ctx->buffer[bytes + pad + 4], &swap_bytes, sizeof (swap_bytes)); + + /* Process last bytes. */ + md5_process_block (ctx->buffer, bytes + pad + 8, ctx); +-- +1.8.2.1 + |