From 4a6fcd75289130da6752195a013d0699ce154ce3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?John=20H=C3=B6gberg?= <john@erlang.org>
Date: Mon, 24 Apr 2023 17:06:27 +0200
Subject: jit: Fix tracing for non-native stack

---
 erts/emulator/beam/jit/x86/instr_trace.cpp | 21 +++++++++++++++------
 1 file changed, 15 insertions(+), 6 deletions(-)

diff --git a/erts/emulator/beam/jit/x86/instr_trace.cpp b/erts/emulator/beam/jit/x86/instr_trace.cpp
index f3a825775d..3e7720c0fc 100644
--- a/erts/emulator/beam/jit/x86/instr_trace.cpp
+++ b/erts/emulator/beam/jit/x86/instr_trace.cpp
@@ -109,10 +109,10 @@ void BeamGlobalAssembler::emit_generic_bp_local() {
     a.cmp(RET, imm(BeamOpCodeAddr(op_i_debug_breakpoint)));
     a.je(labels[debug_bp]);
 
+#ifdef NATIVE_ERLANG_STACK
     /* Note that we don't restore our return addresses in the `debug_bp` case
      * above, since it tail calls the error handler and thus never returns to
      * module code or `call_nif_early`. */
-#ifdef NATIVE_ERLANG_STACK
     a.push(TMP_MEM1q);
     a.push(TMP_MEM2q);
 #endif
@@ -127,6 +127,12 @@ void BeamGlobalAssembler::emit_generic_bp_local() {
 void BeamGlobalAssembler::emit_debug_bp() {
     Label error = a.newLabel();
 
+#ifndef NATIVE_ERLANG_STACK
+    /* We're never going to return to module code, so we have to discard the
+     * return addresses added by the breakpoint trampoline. */
+    a.add(x86::rsp, imm(sizeof(ErtsCodePtr[2])));
+#endif
+
     emit_assert_erlang_stack();
 
     emit_enter_frame();
@@ -203,16 +209,19 @@ void BeamModuleAssembler::emit_i_return_time_trace() {
 }
 
 void BeamModuleAssembler::emit_i_return_to_trace() {
-    emit_enter_runtime<Update::eStack | Update::eHeap>();
+    /* Remove our stack frame so that `beam_jit_return_to_trace` can inspect
+     * the next one.
+     *
+     * (This doesn't do anything if the native stack is used.) */
+    emit_deallocate(ArgWord(0));
+
+    emit_enter_runtime<Update::eReductions | Update::eStack | Update::eHeap>();
 
     a.mov(ARG1, c_p);
     runtime_call<1>(beam_jit_return_to_trace);
 
-    emit_leave_runtime<Update::eStack | Update::eHeap>();
+    emit_leave_runtime<Update::eReductions | Update::eStack | Update::eHeap>();
 
-    /* Remove the zero-sized stack frame. (Will actually do nothing if
-     * the native stack is used.) */
-    emit_deallocate(ArgWord(0));
     emit_return();
 }
 
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