4 files changed, 55 insertions, 9 deletions
diff --git a/debuggerd/libdebuggerd/backtrace.cpp b/debuggerd/libdebuggerd/backtrace.cpp
index 066444242..df49aef37 100644
--- a/debuggerd/libdebuggerd/backtrace.cpp
+++ b/debuggerd/libdebuggerd/backtrace.cpp
@@ -67,15 +67,15 @@ static void dump_process_footer(log_t* log, pid_t pid) {
   _LOG(log, logtype::BACKTRACE, "\n----- end %d -----\n", pid);
 }
 
-static void dump_thread(log_t* log, BacktraceMap* map, pid_t pid, pid_t tid) {
+static void log_thread_name(log_t* log, pid_t tid) {
+  FILE* fp;
+  char buf[1024];
   char path[PATH_MAX];
-  char threadnamebuf[1024];
   char* threadname = NULL;
-  FILE* fp;
 
   snprintf(path, sizeof(path), "/proc/%d/comm", tid);
   if ((fp = fopen(path, "r"))) {
-    threadname = fgets(threadnamebuf, sizeof(threadnamebuf), fp);
+    threadname = fgets(buf, sizeof(buf), fp);
     fclose(fp);
     if (threadname) {
       size_t len = strlen(threadname);
@@ -84,8 +84,11 @@ static void dump_thread(log_t* log, BacktraceMap* map, pid_t pid, pid_t tid) {
       }
     }
   }
-
   _LOG(log, logtype::BACKTRACE, "\n\"%s\" sysTid=%d\n", threadname ? threadname : "<unknown>", tid);
+}
+
+static void dump_thread(log_t* log, BacktraceMap* map, pid_t pid, pid_t tid) {
+  log_thread_name(log, tid);
 
   std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, tid, map));
   if (backtrace->Unwind(0)) {
@@ -112,6 +115,41 @@ void dump_backtrace(int fd, BacktraceMap* map, pid_t pid, pid_t tid,
   dump_process_footer(&log, pid);
 }
 
+void dump_backtrace_ucontext(int output_fd, ucontext_t* ucontext) {
+  pid_t pid = getpid();
+  pid_t tid = gettid();
+
+  log_t log;
+  log.tfd = output_fd;
+  log.amfd_data = nullptr;
+
+  log_thread_name(&log, tid);
+
+  std::unique_ptr<Backtrace> backtrace(Backtrace::Create(pid, tid));
+  if (backtrace->Unwind(0, ucontext)) {
+    dump_backtrace_to_log(backtrace.get(), &log, "  ");
+  } else {
+    ALOGE("Unwind failed: tid = %d: %s", tid,
+          backtrace->GetErrorString(backtrace->GetError()).c_str());
+  }
+}
+
+void dump_backtrace_header(int output_fd) {
+  log_t log;
+  log.tfd = output_fd;
+  log.amfd_data = nullptr;
+
+  dump_process_header(&log, getpid());
+}
+
+void dump_backtrace_footer(int output_fd) {
+  log_t log;
+  log.tfd = output_fd;
+  log.amfd_data = nullptr;
+
+  dump_process_footer(&log, getpid());
+}
+
 void dump_backtrace_to_log(Backtrace* backtrace, log_t* log, const char* prefix) {
   for (size_t i = 0; i < backtrace->NumFrames(); i++) {
     _LOG(log, logtype::BACKTRACE, "%s%s\n", prefix, backtrace->FormatFrameData(i).c_str());
diff --git a/debuggerd/libdebuggerd/include/backtrace.h b/debuggerd/libdebuggerd/include/backtrace.h
index acd5eaac6..5bfdac8fc 100644
--- a/debuggerd/libdebuggerd/include/backtrace.h
+++ b/debuggerd/libdebuggerd/include/backtrace.h
@@ -18,6 +18,7 @@
 #define _DEBUGGERD_BACKTRACE_H
 
 #include <sys/types.h>
+#include <sys/ucontext.h>
 
 #include <set>
 #include <string>
@@ -35,4 +36,8 @@ void dump_backtrace(int fd, BacktraceMap* map, pid_t pid, pid_t tid,
 /* Dumps the backtrace in the backtrace data structure to the log. */
 void dump_backtrace_to_log(Backtrace* backtrace, log_t* log, const char* prefix);
 
+void dump_backtrace_ucontext(int output_fd, ucontext_t* ucontext);
+void dump_backtrace_header(int output_fd);
+void dump_backtrace_footer(int output_fd);
+
 #endif // _DEBUGGERD_BACKTRACE_H
diff --git a/debuggerd/libdebuggerd/include/tombstone.h b/debuggerd/libdebuggerd/include/tombstone.h
index aed71de22..bed371b52 100644
--- a/debuggerd/libdebuggerd/include/tombstone.h
+++ b/debuggerd/libdebuggerd/include/tombstone.h
@@ -39,7 +39,7 @@ void engrave_tombstone(int tombstone_fd, BacktraceMap* map,
                        const std::set<pid_t>* siblings, uintptr_t abort_msg_address,
                        std::string* amfd_data);
 
-void engrave_tombstone_ucontext(int tombstone_fd, pid_t pid, pid_t tid, uintptr_t abort_msg_address,
-                                siginfo_t* siginfo, ucontext_t* ucontext);
+void engrave_tombstone_ucontext(int tombstone_fd, uintptr_t abort_msg_address, siginfo_t* siginfo,
+                                ucontext_t* ucontext);
 
 #endif // _DEBUGGERD_TOMBSTONE_H
diff --git a/debuggerd/libdebuggerd/tombstone.cpp b/debuggerd/libdebuggerd/tombstone.cpp
index 4686bfdc8..c05ccc358 100644
--- a/debuggerd/libdebuggerd/tombstone.cpp
+++ b/debuggerd/libdebuggerd/tombstone.cpp
@@ -751,8 +751,11 @@ void engrave_tombstone(int tombstone_fd, BacktraceMap* map,
   dump_crash(&log, map, open_files, pid, tid, siblings, abort_msg_address);
 }
 
-void engrave_tombstone_ucontext(int tombstone_fd, pid_t pid, pid_t tid, uintptr_t abort_msg_address,
-                                siginfo_t* siginfo, ucontext_t* ucontext) {
+void engrave_tombstone_ucontext(int tombstone_fd, uintptr_t abort_msg_address, siginfo_t* siginfo,
+                                ucontext_t* ucontext) {
+  pid_t pid = getpid();
+  pid_t tid = gettid();
+
   log_t log;
   log.current_tid = tid;
   log.crashed_tid = tid;