diff options
| -rw-r--r-- | erts/emulator/beam/beam_emu.c | 14 |
1 files changed, 13 insertions, 1 deletions
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c index 78ab6fa30f..592cfe273f 100644 --- a/erts/emulator/beam/beam_emu.c +++ b/erts/emulator/beam/beam_emu.c @@ -4326,7 +4326,19 @@ void process_main(void) flags = Arg(2); BsGetFieldSize(tmp_arg2, (flags >> 3), ClauseFail(), size); if (size >= SMALL_BITS) { - Uint wordsneeded = 1+WSIZE(NBYTES((Uint) size)); + Uint wordsneeded; + /* check bits size before potential gc. + * We do not want a gc and then realize we don't need + * the allocated space (i.e. if the op fails) + * + * remember to reacquire the matchbuffer after gc. + */ + + mb = ms_matchbuffer(tmp_arg1); + if (mb->size - mb->offset < size) { + ClauseFail(); + } + wordsneeded = 1+WSIZE(NBYTES((Uint) size)); TestHeapPreserve(wordsneeded, Arg(1), tmp_arg1); } mb = ms_matchbuffer(tmp_arg1); |