File 1033-erts-Check-if-return_to-trace-is-enabled-f... of Package erlang

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File 1033-erts-Check-if-return_to-trace-is-enabled-for-bif.patch of Package erlang (Revision 284afeaf1d86afa1f7b481354a75eb37)

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From 53bf2a9593a2f34151016f7d84fad6d213d76ee9 Mon Sep 17 00:00:00 2001
From: Lukas Larsson <lukas@erlang-solutions.com>
Date: Thu, 7 Jul 2016 20:59:28 +0200
Subject: [PATCH 1/2] erts: Check if return_to trace is enabled for bif

We have to do an extra check if the return_to trace is enabled here
as it may have been cleared by the bif after the flags where
created by the call_trace.
---
 erts/emulator/beam/beam_bp.c             | 3 ++-
 erts/emulator/test/trace_local_SUITE.erl | 8 ++++++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/erts/emulator/beam/beam_bp.c b/erts/emulator/beam/beam_bp.c
index 8489897..920c8b1 100644
--- a/erts/emulator/beam/beam_bp.c
+++ b/erts/emulator/beam/beam_bp.c
@@ -858,7 +858,8 @@ erts_bif_trace(int bif_index, Process* p, Eterm* args, BeamInstr* I)
 	if (flags & MATCH_SET_RX_TRACE) {
 	    erts_trace_return(p, ep->code, result, &ERTS_TRACER(p));
 	}
-	if (flags & MATCH_SET_RETURN_TO_TRACE) {
+	if (flags & MATCH_SET_RETURN_TO_TRACE &&
+            IS_TRACED_FL(p, F_TRACE_RETURN_TO)) {
 	    /* can only happen if(local)*/
 	    if (applying) {
 		/* Apply of BIF, cp is in calling function */
diff --git a/erts/emulator/test/trace_local_SUITE.erl b/erts/emulator/test/trace_local_SUITE.erl
index 74c05f2..c297acd 100644
--- a/erts/emulator/test/trace_local_SUITE.erl
+++ b/erts/emulator/test/trace_local_SUITE.erl
@@ -439,6 +439,14 @@ return_test() ->
     ?RT(?MODULE,slave,2),
     shutdown(),
     ?NM,
+
+    %% Test a regression where turning off return_to tracing
+    %% on yourself would cause a segfault.
+    Pid = setup([call,return_to]),
+    erlang:trace_pattern({'_','_','_'},[],[local]),
+    apply_slave(erlang,trace,[Pid, false, [all]]),
+    shutdown(),
+
     ok.
 
 on_and_off_test() ->
-- 
2.1.4

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File 1033-erts-Check-if-return_to-trace-is-enabled-for-bif.patch of Package erlang (Revision 284afeaf1d86afa1f7b481354a75eb37)

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