tor-browser

commit 9383bc69f7497336f6cdb4739ff80d3aa4b2d1e3
parent a48c7813a3ef97b25731205732d77e20d269f8b3
Author: Ryan Hunt <rhunt@eqrion.net>
Date:   Thu, 18 Dec 2025 16:45:29 +0000

Bug 2002625 - wasm: Dynamically switch to main stack in debug stub. r=yury

Use the infrastructure added for builtin thunks.

Differential Revision: https://phabricator.services.mozilla.com/D274195

Diffstat:
M
js/src/wasm/WasmBuiltins.cpp
 | 
15
++++++++-------
M
js/src/wasm/WasmStubs.cpp
 | 
4
++--

2 files changed, 10 insertions(+), 9 deletions(-)
diff --git a/js/src/wasm/WasmBuiltins.cpp b/js/src/wasm/WasmBuiltins.cpp
@@ -553,6 +553,9 @@ static bool WasmHandleDebugTrap() {
   Instance* instance = GetNearestEffectiveInstance(fp);
   const Code& code = instance->code();
   MOZ_ASSERT(code.debugEnabled());
+#ifdef ENABLE_WASM_JSPI
+  MOZ_ASSERT(!cx->wasm().onSuspendableStack());
+#endif
 
   // The debug trap stub is the innermost frame. It's return address is the
   // actual trap site.
@@ -569,8 +572,7 @@ static bool WasmHandleDebugTrap() {
     }
     debugFrame->setIsDebuggee();
     debugFrame->observe(cx);
-    if (!ForwardToMainStack(DebugAPI::onEnterFrame, cx,
-                            js::AbstractFramePtr(debugFrame))) {
+    if (!DebugAPI::onEnterFrame(cx, js::AbstractFramePtr(debugFrame))) {
       if (cx->isPropagatingForcedReturn()) {
         cx->clearPropagatingForcedReturn();
         // Ignoring forced return because changing code execution order is
@@ -592,9 +594,8 @@ static bool WasmHandleDebugTrap() {
     if (site.kind() == CallSiteKind::CollapseFrame) {
       debugFrame->discardReturnJSValue();
     }
-    bool ok = ForwardToMainStack(DebugAPI::onLeaveFrame, cx,
-                                 js::AbstractFramePtr(debugFrame),
-                                 (const jsbytecode*)nullptr, true);
+    bool ok = DebugAPI::onLeaveFrame(cx, js::AbstractFramePtr(debugFrame),
+                                     (const jsbytecode*)nullptr, true);
     debugFrame->leave(cx);
     return ok;
   }
@@ -602,7 +603,7 @@ static bool WasmHandleDebugTrap() {
   DebugState& debug = instance->debug();
   MOZ_ASSERT(debug.hasBreakpointTrapAtOffset(site.lineOrBytecode()));
   if (debug.stepModeEnabled(debugFrame->funcIndex())) {
-    if (!ForwardToMainStack(DebugAPI::onSingleStep, cx)) {
+    if (!DebugAPI::onSingleStep(cx)) {
       if (cx->isPropagatingForcedReturn()) {
         cx->clearPropagatingForcedReturn();
         // TODO properly handle forced return.
@@ -613,7 +614,7 @@ static bool WasmHandleDebugTrap() {
     }
   }
   if (debug.hasBreakpointSite(site.lineOrBytecode())) {
-    if (!ForwardToMainStack(DebugAPI::onTrap, cx)) {
+    if (!DebugAPI::onTrap(cx)) {
       if (cx->isPropagatingForcedReturn()) {
         cx->clearPropagatingForcedReturn();
         // TODO properly handle forced return.
diff --git a/js/src/wasm/WasmStubs.cpp b/js/src/wasm/WasmStubs.cpp
@@ -2878,7 +2878,7 @@ static bool GenerateDebugStub(MacroAssembler& masm, Label* throwLabel,
   masm.setFramePushed(0);
 
   GenerateExitPrologue(masm, ExitReason::Fixed::DebugStub,
-                       /*switchToMainStack*/ false, 0, 0, offsets);
+                       /*switchToMainStack*/ true, 0, 0, offsets);
 
   uint32_t framePushed = masm.framePushed();
 
@@ -2914,7 +2914,7 @@ static bool GenerateDebugStub(MacroAssembler& masm, Label* throwLabel,
   masm.setFramePushed(framePushed);
 
   GenerateExitEpilogue(masm, ExitReason::Fixed::DebugStub,
-                       /*switchToMainStack*/ false, offsets);
+                       /*switchToMainStack*/ true, offsets);
 
   return FinishOffsets(masm, offsets);
 }