diff options
Diffstat (limited to 'erts/emulator/beam/beam_bp.c')
| -rw-r--r-- | erts/emulator/beam/beam_bp.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/erts/emulator/beam/beam_bp.c b/erts/emulator/beam/beam_bp.c index c81380c14d..871670e8c3 100644 --- a/erts/emulator/beam/beam_bp.c +++ b/erts/emulator/beam/beam_bp.c @@ -419,9 +419,11 @@ erts_install_breakpoints(BpFunctions* f) for (i = 0; i < n; i++) { ErtsCodeInfo* ci = f->matching[i].ci; - BeamInstr *pc = erts_codeinfo_to_code(ci); GenericBp* g = ci->u.gen_bp; - if (*pc != br && g) { + BeamInstr volatile *pc = erts_codeinfo_to_code(ci); + BeamInstr instr = *pc; + + if (!BeamIsOpCode(instr, op_i_generic_breakpoint) && g) { Module* modp = f->matching[i].mod; /* @@ -435,11 +437,16 @@ erts_install_breakpoints(BpFunctions* f) /* * The following write is not protected by any lock. We * assume that the hardware guarantees that a write of an - * aligned word-size (or half-word) writes is atomic - * (i.e. that other processes executing this code will not - * see a half pointer). + * aligned word-size writes is atomic (i.e. that other + * processes executing this code will not see a half + * pointer). + * + * The contents of *pc is marked 'volatile' to ensure that + * the compiler will do a single full-word write, and not + * try any fancy optimizations to write a half word. */ - *pc = br; + instr = BeamSetCodeAddr(instr, br); + *pc = instr; modp->curr.num_breakpoints++; } } |