From bb2f941f5773d8a768b64bbec64bc2731c36e280 Mon Sep 17 00:00:00 2001
From: Peter Collingbourne <pcc@google.com>
Date: Mon, 18 Nov 2019 12:36:50 -0800
Subject: [PATCH] Include PSTATE in tombstones on arm64.

A thread's PSTATE can sometimes be critical for understanding a crash,
especially with MTE and other new features that store per-thread state
in PSTATE.

Bug: 135772972
Change-Id: I1bee25bffe7eea395f04b6449dc9227298cf866e
---
 debuggerd/libdebuggerd/tombstone.cpp              | 2 +-
 libunwindstack/RegsArm64.cpp                      | 2 ++
 libunwindstack/include/unwindstack/MachineArm64.h | 1 +
 libunwindstack/tests/RegsIterateTest.cpp          | 1 +
 4 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index d24672247..e0f8aeb10 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -391,7 +391,7 @@ void dump_registers(log_t* log, unwindstack::Regs* regs) {
   std::vector<std::pair<std::string, uint64_t>> special_row;
 
 #if defined(__arm__) || defined(__aarch64__)
-  static constexpr const char* special_registers[] = {"ip", "lr", "sp", "pc"};
+  static constexpr const char* special_registers[] = {"ip", "lr", "sp", "pc", "pst"};
 #elif defined(__i386__)
   static constexpr const char* special_registers[] = {"ebp", "esp", "eip"};
 #elif defined(__x86_64__)
diff --git a/libunwindstack/RegsArm64.cpp b/libunwindstack/RegsArm64.cpp
index e9787aa46..2e8af20cb 100644
--- a/libunwindstack/RegsArm64.cpp
+++ b/libunwindstack/RegsArm64.cpp
@@ -103,6 +103,7 @@ void RegsArm64::IterateRegisters(std::function<void(const char*, uint64_t)> fn)
   fn("sp", regs_[ARM64_REG_SP]);
   fn("lr", regs_[ARM64_REG_LR]);
   fn("pc", regs_[ARM64_REG_PC]);
+  fn("pst", regs_[ARM64_REG_PSTATE]);
 }
 
 Regs* RegsArm64::Read(void* remote_data) {
@@ -113,6 +114,7 @@ Regs* RegsArm64::Read(void* remote_data) {
   uint64_t* reg_data = reinterpret_cast<uint64_t*>(regs->RawData());
   reg_data[ARM64_REG_PC] = user->pc;
   reg_data[ARM64_REG_SP] = user->sp;
+  reg_data[ARM64_REG_PSTATE] = user->pstate;
   return regs;
 }
 
diff --git a/libunwindstack/include/unwindstack/MachineArm64.h b/libunwindstack/include/unwindstack/MachineArm64.h
index e8b778b13..e95333510 100644
--- a/libunwindstack/include/unwindstack/MachineArm64.h
+++ b/libunwindstack/include/unwindstack/MachineArm64.h
@@ -55,6 +55,7 @@ enum Arm64Reg : uint16_t {
   ARM64_REG_R30,
   ARM64_REG_R31,
   ARM64_REG_PC,
+  ARM64_REG_PSTATE,
   ARM64_REG_LAST,
 
   ARM64_REG_SP = ARM64_REG_R31,
diff --git a/libunwindstack/tests/RegsIterateTest.cpp b/libunwindstack/tests/RegsIterateTest.cpp
index 9a27dbd21..0247a2ae7 100644
--- a/libunwindstack/tests/RegsIterateTest.cpp
+++ b/libunwindstack/tests/RegsIterateTest.cpp
@@ -114,6 +114,7 @@ std::vector<Register> ExpectedRegisters<RegsArm64>() {
   result.push_back({"sp", ARM64_REG_SP});
   result.push_back({"lr", ARM64_REG_LR});
   result.push_back({"pc", ARM64_REG_PC});
+  result.push_back({"pst", ARM64_REG_PSTATE});
   return result;
 }