From 1b306c8a0755aca9de55fee2b02e38d17b696dfd Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Mon, 27 May 2019 20:16:38 +0200
Subject: erts: Fix bug in seq_trace:set_token(label,_)

If internal seq-trace tuple is on old heap
an incorrect ref from old to new heap was made.
---
 lib/kernel/test/seq_trace_SUITE.erl | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)

(limited to 'lib/kernel')

diff --git a/lib/kernel/test/seq_trace_SUITE.erl b/lib/kernel/test/seq_trace_SUITE.erl
index ceb4e9cc49..7c1413287c 100644
--- a/lib/kernel/test/seq_trace_SUITE.erl
+++ b/lib/kernel/test/seq_trace_SUITE.erl
@@ -23,6 +23,7 @@
 	 init_per_group/2,end_per_group/2,
 	 init_per_testcase/2,end_per_testcase/2]).
 -export([token_set_get/1, tracer_set_get/1, print/1,
+         old_heap_token/1,
 	 send/1, distributed_send/1, recv/1, distributed_recv/1,
 	 trace_exit/1, distributed_exit/1, call/1, port/1,
 	 match_set_seq_token/1, gc_seq_token/1, label_capability_mismatch/1]).
@@ -46,6 +47,7 @@ suite() ->
 all() -> 
     [token_set_get, tracer_set_get, print, send,
      distributed_send, recv, distributed_recv, trace_exit,
+     old_heap_token,
      distributed_exit, call, port, match_set_seq_token,
      gc_seq_token, label_capability_mismatch].
 
@@ -531,6 +533,24 @@ get_port_message(Port) ->
     end.
 
 
+%% OTP-15849 ERL-700
+%% Verify changing label on existing token when it resides on old heap.
+%% Bug caused faulty ref from old to new heap.
+old_heap_token(Config) when is_list(Config) ->
+    seq_trace:set_token(label, 1),
+    erlang:garbage_collect(self(), [{type, minor}]),
+    erlang:garbage_collect(self(), [{type, minor}]),
+    %% Now token tuple should be on old-heap.
+    %% Set a new non-literal label which should reside on new-heap.
+    NewLabel = {self(), "new label"},
+    1 = seq_trace:set_token(label, NewLabel),
+
+    %% If bug, we now have a ref from old to new heap. Yet another minor gc
+    %% will make that a ref to deallocated memory.
+    erlang:garbage_collect(self(), [{type, minor}]),
+    {label,NewLabel} = seq_trace:get_token(label),
+    ok.
+
 
 match_set_seq_token(doc) ->
     ["Tests that match spec function set_seq_token does not "
-- 
cgit v1.2.3


From 240acb9617f54761c820bb9a296a2e0256ed83a9 Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Mon, 27 May 2019 20:44:54 +0200
Subject: erts: Fix seq_trace:print/2 for arbitrary labels

Would raise badarg if Label was not atom or small integer.
---
 lib/kernel/test/seq_trace_SUITE.erl | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

(limited to 'lib/kernel')

diff --git a/lib/kernel/test/seq_trace_SUITE.erl b/lib/kernel/test/seq_trace_SUITE.erl
index 7c1413287c..9d97254dc0 100644
--- a/lib/kernel/test/seq_trace_SUITE.erl
+++ b/lib/kernel/test/seq_trace_SUITE.erl
@@ -147,17 +147,19 @@ tracer_set_get(Config) when is_list(Config) ->
     ok.
 
 print(Config) when is_list(Config) ->
-    lists:foreach(fun do_print/1, ?TIMESTAMP_MODES).
+    [do_print(TsType, Label) || TsType <- ?TIMESTAMP_MODES,
+                                Label <- [17, "label"]].
     
-do_print(TsType) ->
+do_print(TsType, Label) ->
     start_tracer(),
+    seq_trace:set_token(label, Label),
     set_token_flags([print, TsType]),
-    seq_trace:print(0,print1),
+    seq_trace:print(Label,print1),
     seq_trace:print(1,print2),
     seq_trace:print(print3),
     seq_trace:reset_trace(),
-    [{0,{print,_,_,[],print1}, Ts0},
-	   {0,{print,_,_,[],print3}, Ts1}] = stop_tracer(2),
+    [{Label,{print,_,_,[],print1}, Ts0},
+     {Label,{print,_,_,[],print3}, Ts1}] = stop_tracer(2),
     check_ts(TsType, Ts0),
     check_ts(TsType, Ts1).
     
-- 
cgit v1.2.3


From 17cf40f734346f67b4d0b708974768f81bc83d2b Mon Sep 17 00:00:00 2001
From: Sverker Eriksson <sverker@erlang.org>
Date: Tue, 28 May 2019 15:34:13 +0200
Subject: erts: Fix faulty spec for seq_trace:set_token/2

Returns plain OldVal.
---
 lib/kernel/src/seq_trace.erl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'lib/kernel')

diff --git a/lib/kernel/src/seq_trace.erl b/lib/kernel/src/seq_trace.erl
index 14fe21e9de..20185dd319 100644
--- a/lib/kernel/src/seq_trace.erl
+++ b/lib/kernel/src/seq_trace.erl
@@ -59,7 +59,7 @@ set_token({Flags,Label,Serial,_From,Lastcnt}) ->
     F = decode_flags(Flags),
     set_token2([{label,Label},{serial,{Lastcnt, Serial}} | F]).
 
--spec set_token(Component, Val) -> {Component, OldVal} when
+-spec set_token(Component, Val) -> OldVal when
       Component :: component(),
       Val :: value(),
       OldVal :: value().
-- 
cgit v1.2.3