diff options
Diffstat (limited to 'erts/emulator/beam/erl_bif_info.c')
-rw-r--r-- | erts/emulator/beam/erl_bif_info.c | 73 |
1 files changed, 51 insertions, 22 deletions
diff --git a/erts/emulator/beam/erl_bif_info.c b/erts/emulator/beam/erl_bif_info.c index 8844012e37..946fefa14f 100644 --- a/erts/emulator/beam/erl_bif_info.c +++ b/erts/emulator/beam/erl_bif_info.c @@ -158,8 +158,9 @@ static Eterm os_version_tuple; static Eterm current_function(Process* p, ErtsHeapFactory *hfact, Process* rp, int full_info, Uint reserve_size, int flags); -static Eterm current_stacktrace(ErtsHeapFactory *hfact, Process* rp, - Uint reserve_size); +static Eterm +current_stacktrace(Process* p, ErtsHeapFactory *hfact, Process* rp, + Uint reserve_size, int flags); Eterm erts_bld_bin_list(Uint **hpp, Uint *szp, ErlOffHeap* oh, Eterm tail) @@ -1383,7 +1384,7 @@ process_info_aux(Process *c_p, break; case ERTS_PI_IX_CURRENT_STACKTRACE: - res = current_stacktrace(hfact, rp, reserve_size); + res = current_stacktrace(c_p, hfact, rp, reserve_size, flags); break; case ERTS_PI_IX_INITIAL_CALL: @@ -2021,21 +2022,44 @@ current_function(Process *c_p, ErtsHeapFactory *hfact, Process* rp, } if (c_p == rp && !(flags & ERTS_PI_FLAG_REQUEST_FOR_OTHER)) { - FunctionInfo fi2; - BeamInstr* continuation_ptr; + BeamInstr* return_address; + FunctionInfo caller_fi; + Eterm *ptr; - /* - * The current function is erlang:process_info/{1,2}, - * which is not the answer that the application want. - * We will use the continuation pointer stored at the - * top of the stack instead. - */ - continuation_ptr = (BeamInstr *) rp->stop[0]; - erts_lookup_function_info(&fi2, continuation_ptr, full_info); - if (fi2.mfa) { - fi = fi2; - rp->current = fi2.mfa; - } + /* + * The current function is erlang:process_info/{1,2}, and we've + * historically returned the *calling* function in that case. We + * therefore use the continuation pointer stored at the top of the + * stack instead, which is safe since process_info is a "heavy" BIF + * that is only called through its export entry. + */ + + return_address = NULL; + ptr = STACK_TOP(rp); + ASSERT(is_CP(*ptr)); + + while (ptr < STACK_START(rp)) { + BeamInstr *cp = cp_val(*ptr); + + if (*cp == BeamOpCodeAddr(op_return_trace)) { + ptr += 3; + } else if (*cp == BeamOpCodeAddr(op_i_return_time_trace)) { + ptr += 2; + } else if (*cp == BeamOpCodeAddr(op_i_return_to_trace)) { + ptr += 1; + } else { + return_address = cp; + break; + } + } + + ASSERT(return_address != NULL); + + erts_lookup_function_info(&caller_fi, return_address, full_info); + if (caller_fi.mfa) { + fi = caller_fi; + rp->current = caller_fi.mfa; + } } /* @@ -2056,8 +2080,8 @@ current_function(Process *c_p, ErtsHeapFactory *hfact, Process* rp, } static Eterm -current_stacktrace(ErtsHeapFactory *hfact, Process* rp, - Uint reserve_size) +current_stacktrace(Process *p, ErtsHeapFactory *hfact, Process* rp, + Uint reserve_size, int flags) { Uint sz; struct StackTrace* s; @@ -2074,9 +2098,14 @@ current_stacktrace(ErtsHeapFactory *hfact, Process* rp, sz = offsetof(struct StackTrace, trace) + sizeof(BeamInstr *)*depth; s = (struct StackTrace *) erts_alloc(ERTS_ALC_T_TMP, sz); s->depth = 0; - if (depth > 0 && rp->i) { - s->trace[s->depth++] = rp->i; - depth--; + s->pc = NULL; + + /* We skip current pc when requesting our own stack trace since it will + * inevitably point to process_info/1,2 */ + if ((p != rp || (flags & ERTS_PI_FLAG_REQUEST_FOR_OTHER)) && + depth > 0 && rp->i) { + s->trace[s->depth++] = rp->i; + depth--; } erts_save_stacktrace(rp, s, depth); |