From 4647b6b3058fd8d17622e72beaea54e64db7afe3 Mon Sep 17 00:00:00 2001
From: Devin Moore <devinmoore@google.com>
Date: Fri, 3 May 2024 00:02:24 +0000
Subject: [PATCH] Add page size info to tombstone

Now that Android devices can use 16k page size, it's important that we
know what configuration the device is in when see issues.

1) If the device is in 4k mode, we see nothing new.

2) If the device is in 16k mode, we see this line in the tombstones:

Page size: 16

3) If the device is in 4k mode, but was previous in 16k mode we see:

Has been in 16kb mode: yes

Test: atest debuggerd_test
Test: atest debuggerd_test with ro.misctrl.16kb_before="1"
Test: adb shell cat /data/tombstones/tombstone_00
Bug: 335247092
Change-Id: If7ca3b0954a01070ff413758296460ca1d023ca5
---
 debuggerd/libdebuggerd/tombstone_proto.cpp         | 3 +++
 debuggerd/libdebuggerd/tombstone_proto_to_text.cpp | 7 +++++++
 debuggerd/proto/tombstone.proto                    | 5 ++++-
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/debuggerd/libdebuggerd/tombstone_proto.cpp b/debuggerd/libdebuggerd/tombstone_proto.cpp
index 4cde98610..5546b7bcc 100644
--- a/debuggerd/libdebuggerd/tombstone_proto.cpp
+++ b/debuggerd/libdebuggerd/tombstone_proto.cpp
@@ -714,6 +714,9 @@ void engrave_tombstone_proto(Tombstone* tombstone, unwindstack::AndroidUnwinder*
                           error.c_str());
   }
 
+  result.set_page_size(getpagesize());
+  result.set_has_been_16kb_mode(android::base::GetBoolProperty("ro.misctrl.16kb_before", false));
+
   auto cmd_line = result.mutable_command_line();
   for (const auto& arg : target_thread.command_line) {
     *cmd_line->Add() = arg;
diff --git a/debuggerd/libdebuggerd/tombstone_proto_to_text.cpp b/debuggerd/libdebuggerd/tombstone_proto_to_text.cpp
index cefa2d62e..08c1cc0da 100644
--- a/debuggerd/libdebuggerd/tombstone_proto_to_text.cpp
+++ b/debuggerd/libdebuggerd/tombstone_proto_to_text.cpp
@@ -586,6 +586,13 @@ bool tombstone_proto_to_text(const Tombstone& tombstone, CallbackType callback)
   CBL("Timestamp: %s", tombstone.timestamp().c_str());
   CBL("Process uptime: %ds", tombstone.process_uptime());
 
+  // only print this info if the page size is not 4k or has been in 16k mode
+  if (tombstone.page_size() != 4096) {
+    CBL("Page size: %d bytes", tombstone.page_size());
+  } else if (tombstone.has_been_16kb_mode()) {
+    CBL("Has been in 16kb mode: yes");
+  }
+
   // Process header
   const auto& threads = tombstone.threads();
   auto main_thread_it = threads.find(tombstone.tid());
diff --git a/debuggerd/proto/tombstone.proto b/debuggerd/proto/tombstone.proto
index 214cbfb46..e70d525ee 100644
--- a/debuggerd/proto/tombstone.proto
+++ b/debuggerd/proto/tombstone.proto
@@ -46,7 +46,10 @@ message Tombstone {
   repeated LogBuffer log_buffers = 18;
   repeated FD open_fds = 19;
 
-  reserved 22 to 999;
+  uint32 page_size = 22;
+  bool has_been_16kb_mode = 23;
+
+  reserved 24 to 999;
 }
 
 enum Architecture {