Dump the per-thread TAGGED_ADDR_CTRL value if available.

This value indicates whether memory tagging is enabled on a thread,
the mode (sync or async) and the set of excluded tags. This information
can sometimes be important for understanding an MTE related crash,
so include it in the per-thread tombstone output.

Bug: 135772972
Change-Id: I25a16e10ac7fbb2b1ab2a961a5279f787039000b

1 files changed, 12 insertions, 0 deletions

diff --git a/debuggerd/crash_dump.cpp b/debuggerd/crash_dump.cpp
index d7cb9725f..c52c6f741 100644
--- a/debuggerd/crash_dump.cpp
+++ b/debuggerd/crash_dump.cpp
@@ -40,6 +40,7 @@
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
 #include <android-base/unique_fd.h>
+#include <bionic/mte_kernel.h>
 #include <bionic/reserved_signals.h>
 #include <cutils/sockets.h>
 #include <log/log.h>
@@ -486,6 +487,17 @@ int main(int argc, char** argv) {
         continue;
       }
 
+#ifdef ANDROID_EXPERIMENTAL_MTE
+      struct iovec iov = {
+          &info.tagged_addr_ctrl,
+          sizeof(info.tagged_addr_ctrl),
+      };
+      if (ptrace(PTRACE_GETREGSET, thread, NT_ARM_TAGGED_ADDR_CTRL,
+                 reinterpret_cast<void*>(&iov)) == -1) {
+        info.tagged_addr_ctrl = -1;
+      }
+#endif
+
       if (thread == g_target_thread) {
         // Read the thread's registers along with the rest of the crash info out of the pipe.
         ReadCrashInfo(input_pipe, &siginfo, &info.registers, &process_info);