From 1cdc7aa0387bc4fe68a39b2e96519cf4269f6227 Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sun, 19 Dec 2021 16:41:07 +0100
Subject: [PATCH] Kernel: Mask kernel addresses in perf event streams for
 non-superuser

We now turn kernel addresses into 0xdeadc0de, same as /proc/PID/stacks/
---
 Kernel/PerformanceEventBuffer.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/Kernel/PerformanceEventBuffer.cpp b/Kernel/PerformanceEventBuffer.cpp
index 38c04fe14f..d3d8901e08 100644
--- a/Kernel/PerformanceEventBuffer.cpp
+++ b/Kernel/PerformanceEventBuffer.cpp
@@ -286,7 +286,10 @@ ErrorOr<void> PerformanceEventBuffer::to_json_impl(Serializer& object) const
             seen_first_sample = true;
         auto stack_array = event_object.add_array("stack");
         for (size_t j = 0; j < event.stack_size; ++j) {
-            stack_array.add(event.stack[j]);
+            auto address = event.stack[j];
+            if (!show_kernel_addresses && !Memory::is_user_address(VirtualAddress { address }))
+                address = 0xdeadc0de;
+            stack_array.add(address);
         }
         stack_array.finish();
         event_object.finish();