[profiler] Use FilterContext to filter VMState in Samples

To avoid leaking VMState cross origin leverage existing FilterContext
to filter out VMSTates.
GC State is the exception as it is not coupled to any native context and
is always included.

Bug: chromium:1263871
Change-Id: I5cab8620460f4db24fa183c891cb0c43996e95c4
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3465735
Auto-Submit: Corentin Pescheloche <cpescheloche@fb.com>
Reviewed-by: Camillo Bruni <cbruni@chromium.org>
Commit-Queue: Camillo Bruni <cbruni@chromium.org>
Cr-Commit-Position: refs/heads/main@{#79234}

src/profiler/profile-generator.cc

@@ -1005,6 +1005,13 @@ void CpuProfilesCollection::AddPathToCurrentProfiles(
     bool accepts_context = context_filter.Accept(native_context_address);
     bool accepts_embedder_context =
         context_filter.Accept(embedder_native_context_address);
+
+    // if FilterContext is set, do not propagate StateTag if not accepted.
+    // GC is exception because native context address is guaranteed to be empty.
+    DCHECK(state != StateTag::GC || native_context_address == kNullAddress);
+    if (!accepts_context && state != StateTag::GC) {
+      state = StateTag::IDLE;
+    }
     profile->AddPath(timestamp, accepts_context ? path : empty_path, src_line,
                      update_stats, sampling_interval, state,
                      accepts_embedder_context ? embedder_state_tag

src/profiler/tick-sample.cc

@@ -226,6 +226,13 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
     sample_info->embedder_state = embedder_state->GetState();
   }
 
+  Context top_context = isolate->context();
+  if (top_context.ptr() != i::Context::kNoContext &&
+      top_context.ptr() != i::Context::kInvalidContext) {
+    NativeContext top_native_context = top_context.native_context();
+    sample_info->context = reinterpret_cast<void*>(top_native_context.ptr());
+  }
+
   i::Address js_entry_sp = isolate->js_entry_sp();
   if (js_entry_sp == 0) return true;  // Not executing JS now.
 
@@ -293,13 +300,6 @@ bool TickSample::GetStackSample(Isolate* v8_isolate, RegisterState* regs,
                                reinterpret_cast<i::Address>(regs->lr),
                                js_entry_sp);
 
-  Context top_context = isolate->context();
-  if (top_context.ptr() != i::Context::kNoContext &&
-      top_context.ptr() != i::Context::kInvalidContext) {
-    NativeContext top_native_context = top_context.native_context();
-    sample_info->context = reinterpret_cast<void*>(top_native_context.ptr());
-  }
-
   if (it.done()) return true;
 
   size_t i = 0;

test/cctest/test-cpu-profiler.cc

@@ -3920,6 +3920,15 @@ TEST(ContextIsolation) {
         diff_context_profile->GetTopDownRoot();
     // Ensure that no children were recorded (including callbacks, builtins).
     CHECK(!FindChild(diff_root, "start"));
+
+    CHECK_GT(diff_context_profile->GetSamplesCount(), 0);
+    for (int i = 0; i < diff_context_profile->GetSamplesCount(); i++) {
+      CHECK(diff_context_profile->GetSampleState(i) == StateTag::IDLE ||
+            // GC State do not have a context
+            diff_context_profile->GetSampleState(i) == StateTag::GC ||
+            // first frame and native code reports as external
+            diff_context_profile->GetSampleState(i) == StateTag::EXTERNAL);
+    }
   }
 }