diff options
| -rw-r--r-- | erts/emulator/beam/external.h | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/erts/emulator/beam/external.h b/erts/emulator/beam/external.h index aa124f5197..727333d539 100644 --- a/erts/emulator/beam/external.h +++ b/erts/emulator/beam/external.h @@ -98,10 +98,19 @@ typedef struct { Eterm atom[ERTS_ATOM_CACHE_SIZE]; } ErtsAtomTranslationTable; -#define ERTS_DIST_EXT_DFLAG_HDR (((Uint32) 1) << 31) -#define ERTS_DIST_EXT_ATOM_TRANS_TAB (((Uint32) 1) << 30) -#define ERTS_DIST_EXT_BTT_SAFE (((Uint32) 1) << 29) -#define ERTS_DIST_EXT_CON_ID_MASK ((Uint32) 0x1fffffff) +/* + * These flags are tagged onto the high bits of a connection ID and stored in + * the ErtsDistExternal structure's flags field. They are used to indicate + * various bits of state necessary to decode binaries in a variety of + * scenarios. The mask ERTS_DIST_EXT_CON_ID_MASK is used later to separate the + * connection ID from the flags. Be careful to ensure that the mask does not + * overlap any of the bits used for flags, or ERTS will leak flags bits into + * connection IDs and leak connection ID bits into the flags. + */ +#define ERTS_DIST_EXT_DFLAG_HDR ((Uint32) 0x80000000) +#define ERTS_DIST_EXT_ATOM_TRANS_TAB ((Uint32) 0x40000000) +#define ERTS_DIST_EXT_BTT_SAFE ((Uint32) 0x20000000) +#define ERTS_DIST_EXT_CON_ID_MASK ((Uint32) 0x1fffffff) #define ERTS_DIST_EXT_CON_ID(DIST_EXTP) \ ((DIST_EXTP)->flags & ERTS_DIST_EXT_CON_ID_MASK) |