[inspector] Prevent regex breakpoints from re-entering the debugger

This patch uses the postpone-interrupts scope to prevent regexes
from re-entering the debugger when matching regex breakpoints
(while setting or removing regex breakpoints).

The test is separate in a Blink CL: crrev.com/c/4355146

Bug: chromium:1426163
Change-Id: I4eb7873645a02c286664e0b6ddb53b9fb7db64f6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/4355440
Reviewed-by: Simon Zünd <szuend@chromium.org>
Commit-Queue: Jaroslav Sevcik <jarin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#86621}

src/inspector/v8-debugger-agent-impl.cc

@@ -673,6 +673,9 @@ Response V8DebuggerAgentImpl::setBreakpointByUrl(
   std::unique_ptr<protocol::DictionaryValue> hint;
   for (const auto& script : m_scripts) {
     if (!matcher.matches(*script.second)) continue;
+    // Make sure the session was not disabled by some re-entrant call
+    // in the script matcher.
+    DCHECK(enabled());
     int adjustedLineNumber = lineNumber;
     int adjustedColumnNumber = columnNumber;
     if (hint) {
@@ -810,6 +813,9 @@ Response V8DebuggerAgentImpl::removeBreakpoint(const String16& breakpointId) {
   std::vector<V8DebuggerScript*> scripts;
   for (const auto& scriptIter : m_scripts) {
     const bool scriptSelectorMatch = matcher.matches(*scriptIter.second);
+    // Make sure the session was not disabled by some re-entrant call
+    // in the script matcher.
+    DCHECK(enabled());
     const bool isInstrumentation =
         type == BreakpointType::kInstrumentationBreakpoint;
     if (!scriptSelectorMatch && !isInstrumentation) continue;
@@ -1980,6 +1986,9 @@ void V8DebuggerAgentImpl::didParseSource(
       Matcher matcher(m_inspector, type, selector);
 
       if (!matcher.matches(*scriptRef)) continue;
+      // Make sure the session was not disabled by some re-entrant call
+      // in the script matcher.
+      DCHECK(enabled());
       String16 condition;
       breakpointWithCondition.second->asString(&condition);
       protocol::DictionaryValue* hint =

src/inspector/v8-regex.cc

@@ -36,6 +36,8 @@ V8Regex::V8Regex(V8InspectorImpl* inspector, const String16& pattern,
   if (multiline) flags |= v8::RegExp::kMultiline;
 
   v8::Local<v8::RegExp> regex;
+  // Protect against reentrant debugger calls via interrupts.
+  v8::debug::PostponeInterruptsScope no_interrupts(m_inspector->isolate());
   if (v8::RegExp::New(context, toV8String(isolate, pattern),
                       static_cast<v8::RegExp::Flags>(flags))
           .ToLocal(&regex))
@@ -65,6 +67,8 @@ int V8Regex::match(const String16& string, int startFrom,
   v8::Context::Scope contextScope(context);
   v8::MicrotasksScope microtasks(context,
                                  v8::MicrotasksScope::kDoNotRunMicrotasks);
+  // Protect against reentrant debugger calls via interrupts.
+  v8::debug::PostponeInterruptsScope no_interrupts(m_inspector->isolate());
   v8::TryCatch tryCatch(isolate);
 
   v8::Local<v8::RegExp> regex = m_regex.Get(isolate);