https://github.com/kjn/lbzip2/pull/25 From d570020ade2add591b97e61927545a005a2d4a6f Mon Sep 17 00:00:00 2001 From: Matt Turner 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))); };