| https://github.com/kjn/lbzip2/pull/25 |
| |
| From d570020ade2add591b97e61927545a005a2d4a6f Mon Sep 17 00:00:00 2001 |
| From: Matt Turner <mattst88@gmail.com> |
| Date: Wed, 7 Aug 2019 11:47:04 -0700 |
| Subject: [PATCH] Align zero-length array to avoid unaligned accesses |
| |
| When make_tree() creates the left-justified base table (uint64_t *B) |
| it does so with 64-bit stores: |
| |
| B[k] = sofar; |
| |
| But B points to memory in the zero-length array "uint32_t tt[0]" at the |
| end of struct decoder_state. Since tt's type is uint32_t, it is only |
| aligned to a four byte boundary, and so the 64-bit store in make_tree() |
| causes an unaligned trap on strict platforms like sparc. |
| --- |
| src/decode.h | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/src/decode.h b/src/decode.h |
| index c9a9086..7c0ca3f 100644 |
| --- a/src/decode.h |
| +++ b/src/decode.h |
| @@ -62,7 +62,7 @@ struct decoder_state { |
| uint8_t rle_char; /* current character */ |
| uint8_t rle_prev; /* prevoius character */ |
| |
| - uint32_t tt[0]; |
| + uint32_t tt[0] __attribute__((aligned (8))); |
| }; |
| |
| |
