File 0207-erts-Fix-handling-of-Export.is_bif_traced-for-multi-.patch of Package erlang
From d974e8cb9ee7b477960bdde697142a26783bef99 Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Thu, 23 Oct 2025 20:22:24 +0200
Subject: [PATCH] erts: Fix handling of Export.is_bif_traced for multi sessions
Problem:
Export.is_bif_traced was prematurely cleared when the first GenericBp
breakpoint was unlinked which caused tracing of the BIF for remaining
sessions to be ignored.
Solution:
Set 'is_bif_traced' if we have at least one GenericBp.
Clear 'is_bif_traced' when the last GenericBp disappears.
---
erts/emulator/beam/beam_bif_load.c | 6 +-
erts/emulator/beam/beam_bp.c | 52 ++++++++++-
erts/emulator/beam/beam_bp.h | 5 +-
erts/emulator/beam/beam_load.c | 2 +
erts/emulator/beam/erl_bif_trace.c | 100 ++++++++++-----------
erts/emulator/test/trace_session_SUITE.erl | 86 +++++++++++++++++-
6 files changed, 188 insertions(+), 63 deletions(-)
diff --git a/erts/emulator/beam/beam_bif_load.c b/erts/emulator/beam/beam_bif_load.c
index e0cd379bab..af3990eb33 100644
--- a/erts/emulator/beam/beam_bif_load.c
+++ b/erts/emulator/beam/beam_bif_load.c
@@ -2237,10 +2237,8 @@ delete_code(Module* modp)
}
}
- if (ep->bif_number != -1 && ep->is_bif_traced) {
- /* Code unloading kills both global and local call tracing. */
- ep->is_bif_traced = 0;
- }
+ ASSERT(!erts_export_is_bif_traced(ep));
+ ep->is_bif_traced = 0;
ep->trampoline.common.op = BeamOpCodeAddr(op_call_error_handler);
ep->trampoline.not_loaded.deferred = 0;
diff --git a/erts/emulator/beam/beam_bp.c b/erts/emulator/beam/beam_bp.c
index 294fa6c7ca..0e7b49a6f4 100644
--- a/erts/emulator/beam/beam_bp.c
+++ b/erts/emulator/beam/beam_bp.c
@@ -299,8 +299,34 @@ erts_bp_free_matched_functions(BpFunctions* f)
else ASSERT(f->matched == 0);
}
-void
-erts_consolidate_export_bp_data(BpFunctions* f)
+/*
+ * Return correct value for Export.is_bif_traced.
+ * true if BIF and breakpoint exist in either export trampoline or code,
+ * false otherwise.
+*/
+int erts_export_is_bif_traced(const Export *ep)
+{
+ if (ep->bif_number < 0) {
+ ASSERT(!ep->is_bif_traced);
+ return 0;
+ }
+
+ if (ep->info.gen_bp) {
+ return 1;
+ }
+ else {
+ ErtsCodePtr code = ep->dispatch.addresses[erts_active_code_ix()];
+ const ErtsCodeInfo *ci = erts_code_to_codeinfo(code);
+ ASSERT(ci->mfa.module == ep->info.mfa.module);
+ ASSERT(ci->mfa.function == ep->info.mfa.function);
+ ASSERT(ci->mfa.arity == ep->info.mfa.arity);
+
+ return (ci->gen_bp != NULL);
+ }
+}
+
+static void
+consolidate_export_bp_data(BpFunctions* f)
{
BpFunction* fs = f->matching;
Uint i, n;
@@ -312,6 +338,7 @@ erts_consolidate_export_bp_data(BpFunctions* f)
for (i = 0; i < n; i++) {
struct erl_module_instance *mi;
ErtsCodeInfo *ci_rw;
+ Export* ep;
mi = fs[i].mod ? &fs[i].mod->curr : NULL;
@@ -324,6 +351,9 @@ erts_consolidate_export_bp_data(BpFunctions* f)
mi->code_length));
consolidate_bp_data(mi, ci_rw, 0);
+
+ ep = ErtsContainerStruct(ci_rw, Export, info);
+ ep->is_bif_traced = erts_export_is_bif_traced(ep);
}
}
@@ -365,6 +395,19 @@ erts_consolidate_local_bp_data(BpFunctions* f)
}
}
+void
+erts_consolidate_all_bp_data(BpFunctions* f, BpFunctions* e)
+{
+ erts_consolidate_local_bp_data(f);
+ /*
+ * Must do export entries *after* module code
+ * so breakpoints in code have been cleared and
+ * Export.is_bif_traced can be updated accordingly.
+ */
+ consolidate_export_bp_data(e);
+}
+
+
void
erts_free_breakpoints(void)
{
@@ -710,9 +753,10 @@ erts_set_mtrace_break(BpFunctions* f, Binary *match_spec, ErtsTracer tracer)
}
void
-erts_set_export_trace(ErtsCodeInfo *ci, Binary *match_spec)
+erts_set_export_trace(Export* ep, Binary *match_spec)
{
- set_function_break(ci, match_spec, ERTS_BPF_GLOBAL_TRACE, 0, erts_tracer_nil);
+ set_function_break(&ep->info, match_spec, ERTS_BPF_GLOBAL_TRACE, 0,
+ erts_tracer_nil);
}
void
diff --git a/erts/emulator/beam/beam_bp.h b/erts/emulator/beam/beam_bp.h
index 3e8bca39c3..6a5b4b5b8b 100644
--- a/erts/emulator/beam/beam_bp.h
+++ b/erts/emulator/beam/beam_bp.h
@@ -142,14 +142,15 @@ Uint erts_sum_all_session_flags(ErtsCodeInfo *ci_rw);
void erts_uninstall_breakpoints(BpFunctions* f);
void erts_consolidate_local_bp_data(BpFunctions* f);
-void erts_consolidate_export_bp_data(BpFunctions* f);
+void erts_consolidate_all_bp_data(BpFunctions* f, BpFunctions* e);
void erts_free_breakpoints(void);
void erts_set_trace_break(BpFunctions *f, Binary *match_spec);
void erts_clear_trace_break(BpFunctions *f);
-void erts_set_export_trace(ErtsCodeInfo *ci, Binary *match_spec);
+void erts_set_export_trace(Export *ep, Binary *match_spec);
void erts_clear_export_trace(ErtsCodeInfo *ci);
+int erts_export_is_bif_traced(const Export*);
void erts_set_mtrace_break(BpFunctions *f, Binary *match_spec, ErtsTracer tracer);
void erts_clear_mtrace_break(BpFunctions *f);
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 543ed9f017..1139472f70 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -281,6 +281,8 @@ erts_finish_loading(Binary* magic, Process* c_p,
ASSERT(ep->trampoline.breakpoint.address == 0);
}
+ ASSERT(!erts_export_is_bif_traced(ep));
+ ep->is_bif_traced = 0;
}
ASSERT(mod_tab_p->curr.num_breakpoints == 0);
ASSERT(mod_tab_p->curr.num_traced_exports == 0);
diff --git a/erts/emulator/beam/erl_bif_trace.c b/erts/emulator/beam/erl_bif_trace.c
index eb57056c2b..6c965ba36a 100644
--- a/erts/emulator/beam/erl_bif_trace.c
+++ b/erts/emulator/beam/erl_bif_trace.c
@@ -2387,54 +2387,13 @@ erts_set_trace_pattern(ErtsCodeMFA *mfa, int specified,
ErtsTracer meta_tracer, int is_blocking)
{
const ErtsCodeIndex code_ix = erts_active_code_ix();
- Uint i, n, matches;
+ Uint i, n;
+ Uint matches = 0;
BpFunction* fp;
- erts_bp_match_export(&finish_bp.e, mfa, specified);
-
- fp = finish_bp.e.matching;
- n = finish_bp.e.matched;
- matches = 0;
-
- for (i = 0; i < n; i++) {
- ErtsCodeInfo *ci_rw;
- Export* ep;
-
- /* Export entries are always writable, discard const. */
- ci_rw = (ErtsCodeInfo *)fp[i].code_info;
- ep = ErtsContainerStruct(ci_rw, Export, info);
-
- if (ep->bif_number != -1) {
- ep->is_bif_traced = !!on;
- }
-
- if (on && !flags.breakpoint) {
- /* Turn on global call tracing */
- if (!erts_is_export_trampoline_active(ep, code_ix)) {
- fp[i].mod->curr.num_traced_exports++;
-#if defined(DEBUG) && !defined(BEAMASM)
- ep->info.u.op = BeamOpCodeAddr(op_i_func_info_IaaI);
-#endif
- ep->trampoline.breakpoint.op = BeamOpCodeAddr(op_i_generic_breakpoint);
- ep->trampoline.breakpoint.address =
- (BeamInstr) ep->dispatch.addresses[code_ix];
- }
- erts_set_export_trace(ci_rw, match_prog_set);
-
- } else if (!on && flags.breakpoint) {
- /* Turn off breakpoint tracing -- nothing to do here. */
- } else {
- /*
- * Turn off global tracing, either explicitly or implicitly
- * before turning on breakpoint tracing.
- */
- erts_clear_export_trace(ci_rw);
- }
- }
-
/*
- ** So, now for code breakpoint tracing
- */
+ * First do "local" code breakpoint tracing
+ */
erts_bp_match_functions(&finish_bp.f, mfa, specified);
if (on) {
@@ -2476,6 +2435,49 @@ erts_set_trace_pattern(ErtsCodeMFA *mfa, int specified,
}
}
+ /*
+ * Do export entries *after* module code, when breakpoints have been set
+ * and Export.is_bif_traced can be updated accordingly.
+ */
+ erts_bp_match_export(&finish_bp.e, mfa, specified);
+
+ fp = finish_bp.e.matching;
+ n = finish_bp.e.matched;
+
+ for (i = 0; i < n; i++) {
+ ErtsCodeInfo *ci_rw;
+ Export* ep;
+
+ /* Export entries are always writable, discard const. */
+ ci_rw = (ErtsCodeInfo *)fp[i].code_info;
+ ep = ErtsContainerStruct(ci_rw, Export, info);
+
+ if (on && !flags.breakpoint) {
+ /* Turn on global call tracing */
+ if (!erts_is_export_trampoline_active(ep, code_ix)) {
+ fp[i].mod->curr.num_traced_exports++;
+#if defined(DEBUG) && !defined(BEAMASM)
+ ep->info.u.op = BeamOpCodeAddr(op_i_func_info_IaaI);
+#endif
+ ep->trampoline.breakpoint.op = BeamOpCodeAddr(op_i_generic_breakpoint);
+ ep->trampoline.breakpoint.address =
+ (BeamInstr) ep->dispatch.addresses[code_ix];
+ }
+ erts_set_export_trace(ep, match_prog_set);
+
+ } else if (!on && flags.breakpoint) {
+ /* Turn off breakpoint tracing -- nothing to do here. */
+ } else {
+ /*
+ * Turn off global tracing, either explicitly or implicitly
+ * before turning on breakpoint tracing.
+ */
+ erts_clear_export_trace(ci_rw);
+ }
+
+ ep->is_bif_traced = erts_export_is_bif_traced(ep);
+ }
+
finish_bp.current = 0;
finish_bp.install = on;
finish_bp.local = flags.breakpoint;
@@ -2515,15 +2517,10 @@ prepare_clear_all_trace_pattern(ErtsTraceSession* session)
for (i = 0; i < n; i++) {
ErtsCodeInfo *ci_rw;
- Export* ep;
/* Export entries are always writable, discard const. */
ci_rw = (ErtsCodeInfo *)fp[i].code_info;
- ep = ErtsContainerStruct(ci_rw, Export, info);
- if (ep->bif_number != -1) {
- ep->is_bif_traced = 0; // ToDo: multi sessions?
- }
erts_clear_export_trace(ci_rw);
}
@@ -2686,8 +2683,7 @@ erts_finish_breakpointing(void)
* deallocate the GenericBp structs for them.
*/
clean_export_entries(&finish_bp.e);
- erts_consolidate_export_bp_data(&finish_bp.e);
- erts_consolidate_local_bp_data(&finish_bp.f);
+ erts_consolidate_all_bp_data(&finish_bp.f, &finish_bp.e);
erts_bp_free_matched_functions(&finish_bp.e);
erts_bp_free_matched_functions(&finish_bp.f);
consolidate_event_tracing(erts_staging_trace_session->send_tracing);
diff --git a/erts/emulator/test/trace_session_SUITE.erl b/erts/emulator/test/trace_session_SUITE.erl
index f80bc4fa55..dcbe6688bd 100644
--- a/erts/emulator/test/trace_session_SUITE.erl
+++ b/erts/emulator/test/trace_session_SUITE.erl
@@ -37,6 +37,8 @@
destroy/1,
negative/1,
error_info/1,
+ is_bif_traced/1,
+
end_of_list/1]).
-include_lib("common_test/include/ct.hrl").
@@ -72,6 +74,8 @@ all() ->
destroy,
negative,
error_info,
+ is_bif_traced,
+
end_of_list].
init_per_suite(Config) ->
@@ -1634,6 +1638,86 @@ tracer_loop(Name, Tester) ->
tracer_loop(Name, Tester).
+%% OTP-19840: Verify setting/clearing of 'is_bif_traced' in export entry
+%% works correctly for multiple sessions.
+is_bif_traced(_Config) ->
+ CallTypes = [global, local],
+ [is_bif_traced_do(CT1, CT2, CT3)
+ || CT1 <- CallTypes, CT2 <- CallTypes, CT3 <- CallTypes],
+ ok.
+
+is_bif_traced_do(CT1, CT2, CT3) ->
+ io:format("CT1=~w, CT2=~w, CT3=~w\n", [CT1, CT2, CT3]),
+
+ Tester = self(),
+ TracerFun = fun F() -> receive M -> Tester ! {self(), M} end, F() end,
+ T1 = spawn_link(TracerFun),
+ S1 = trace:session_create(one, T1, []),
+
+ %% A benign BIF call that does not get optimized away
+ BIF = {erlang,phash2,1},
+ {M,F,A} = BIF,
+ true = erlang:is_builtin(M,F,A),
+
+ trace:function(S1, BIF, true, [CT1]),
+ trace:process(S1, self(), true, [call]),
+
+ M:F("S1"),
+ {T1, {trace,Tester,call,{M,F,["S1"]}}} = receive_any(),
+
+ T2 = spawn_link(TracerFun),
+ S2 = trace:session_create(two, T2, []),
+ trace:function(S2, BIF, true, [CT2]),
+ trace:process(S2, self(), true, [call]),
+
+ M:F("S1 & S2"),
+ receive_parallel_list(
+ [[{T1, {trace,Tester,call,{M,F,["S1 & S2"]}}}],
+ [{T2, {trace,Tester,call,{M,F,["S1 & S2"]}}}]]),
+
+ T3 = spawn_link(TracerFun),
+ S3 = trace:session_create(three, T3, []),
+ trace:function(S3, BIF, true, [CT3]),
+ trace:process(S3, self(), true, [call]),
+
+ M:F("S1 & S2 & S3"),
+ receive_parallel_list(
+ [[{T1, {trace,Tester,call,{M,F,["S1 & S2 & S3"]}}}],
+ [{T2, {trace,Tester,call,{M,F,["S1 & S2 & S3"]}}}],
+ [{T3, {trace,Tester,call,{M,F,["S1 & S2 & S3"]}}}]]),
+
+ %% Remove not last BIF trace nicely
+ trace:function(S1, BIF, false, [CT1]),
+ M:F("S2 & S3"),
+ receive_parallel_list(
+ [[{T2, {trace,Tester,call,{M,F,["S2 & S3"]}}}],
+ [{T3, {trace,Tester,call,{M,F,["S2 & S3"]}}}]]),
+
+ %% Remove not last BIF trace by session destruction
+ trace:session_destroy(S2),
+ M:F("S3"),
+ receive_parallel_list(
+ [[{T3, {trace,Tester,call,{M,F,["S3"]}}}]]),
+
+ %% Remove last BIF trace nicely
+ trace:function(S3, BIF, false, [CT3]),
+ M:F("no trace"),
+ receive_nothing(),
+
+ trace:function(S1, BIF, true, [CT1]),
+ M:F("S1"),
+ receive_parallel_list(
+ [[{T1, {trace,Tester,call,{M,F,["S1"]}}}]]),
+
+ %% Remove last BIF trace by session destruction
+ trace:session_destroy(S1),
+ M:F("no trace"),
+ receive_nothing(),
+
+ trace:session_destroy(S3),
+ ok.
+
+
receive_any() ->
receive_any(1000).
--
2.51.0
