From 4fb0813f9004cb75eca065058c4899b0e4183635 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?John=20H=C3=B6gberg?= Date: Wed, 24 Apr 2019 12:45:36 +0200 Subject: erts_alloc: Fix incorrect header word packing --- erts/emulator/beam/erl_alloc_util.c | 8 ++++++++ erts/emulator/beam/erl_alloc_util.h | 5 +++-- 2 files changed, 11 insertions(+), 2 deletions(-) diff --git a/erts/emulator/beam/erl_alloc_util.c b/erts/emulator/beam/erl_alloc_util.c index 8d4464969a..25ac3bc5af 100644 --- a/erts/emulator/beam/erl_alloc_util.c +++ b/erts/emulator/beam/erl_alloc_util.c @@ -6567,6 +6567,14 @@ erts_alcu_start(Allctr_t *allctr, AllctrInit_t *init) __FILE__, __LINE__); } + /* The various fields packed into the header word must not overlap */ + ERTS_CT_ASSERT(!(MBC_ABLK_OFFSET_MASK & MBC_ABLK_SZ_MASK)); + ERTS_CT_ASSERT(!(MBC_ABLK_OFFSET_MASK & BLK_FLG_MASK)); + ERTS_CT_ASSERT(!(MBC_ABLK_SZ_MASK & BLK_FLG_MASK)); + ERTS_CT_ASSERT(!(MBC_FBLK_SZ_MASK & BLK_FLG_MASK)); + ERTS_CT_ASSERT(!(SBC_BLK_SZ_MASK & BLK_FLG_MASK)); + ERTS_CT_ASSERT(!(CRR_SZ_MASK & CRR_FLG_MASK)); + if (!initialized) goto error; diff --git a/erts/emulator/beam/erl_alloc_util.h b/erts/emulator/beam/erl_alloc_util.h index ea1afe8f58..b34916271e 100644 --- a/erts/emulator/beam/erl_alloc_util.h +++ b/erts/emulator/beam/erl_alloc_util.h @@ -334,8 +334,9 @@ void erts_alcu_sched_spec_data_init(struct ErtsSchedulerData_ *esdp); #endif #if MBC_ABLK_OFFSET_BITS -# define MBC_ABLK_OFFSET_SHIFT (sizeof(UWord)*8 - MBC_ABLK_OFFSET_BITS) -# define MBC_ABLK_OFFSET_MASK ((~((UWord)0) << MBC_ABLK_OFFSET_SHIFT) & ~BLK_FLG_MASK) +/* The shift is reduced by 1 since the highest bit is used for a flag. */ +# define MBC_ABLK_OFFSET_SHIFT (sizeof(UWord)*8 - 1 - MBC_ABLK_OFFSET_BITS) +# define MBC_ABLK_OFFSET_MASK (((1ul << MBC_ABLK_OFFSET_BITS) - 1ul) << MBC_ABLK_OFFSET_SHIFT) # define MBC_ABLK_SZ_MASK (~MBC_ABLK_OFFSET_MASK & ~BLK_FLG_MASK) #else # define MBC_ABLK_SZ_MASK (~BLK_FLG_MASK) -- cgit v1.2.3