1 files changed, 53 insertions, 42 deletions

diff --git a/debuggerd/utility.cpp b/debuggerd/utility.cpp
index d4c252f..2baf9de 100644
--- a/debuggerd/utility.cpp
+++ b/debuggerd/utility.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define LOG_TAG "DEBUG"
+
 #include "utility.h"
 
 #include <errno.h>
@@ -25,10 +27,9 @@
 
 #include <backtrace/Backtrace.h>
 #include <log/log.h>
-#include <log/logd.h>
 
-const int sleep_time_usec = 50000;         // 0.05 seconds
-const int max_total_sleep_usec = 10000000; // 10 seconds
+const int SLEEP_TIME_USEC = 50000;         // 0.05 seconds
+const int MAX_TOTAL_SLEEP_USEC = 10000000; // 10 seconds
 
 static int write_to_am(int fd, const char* buf, int len) {
   int to_write = len;
@@ -36,7 +37,7 @@ static int write_to_am(int fd, const char* buf, int len) {
     int written = TEMP_FAILURE_RETRY(write(fd, buf + len - to_write, to_write));
     if (written < 0) {
       // hard failure
-      LOG("AM write failure (%d / %s)\n", errno, strerror(errno));
+      ALOGE("AM write failure (%d / %s)\n", errno, strerror(errno));
       return -1;
     }
     to_write -= written;
@@ -44,10 +45,24 @@ static int write_to_am(int fd, const char* buf, int len) {
   return len;
 }
 
-void _LOG(log_t* log, int scopeFlags, const char* fmt, ...) {
-  bool want_tfd_write = log && log->tfd >= 0;
-  bool want_log_write = IS_AT_FAULT(scopeFlags) && (!log || !log->quiet);
-  bool want_amfd_write = IS_AT_FAULT(scopeFlags) && !IS_SENSITIVE(scopeFlags) && log && log->amfd >= 0;
+// Whitelist output desired in the logcat output.
+bool is_allowed_in_logcat(enum logtype ltype) {
+  if ((ltype == ERROR)
+   || (ltype == HEADER)
+   || (ltype == REGISTERS)
+   || (ltype == BACKTRACE)) {
+    return true;
+  }
+  return false;
+}
+
+void _LOG(log_t* log, enum logtype ltype, const char* fmt, ...) {
+  bool write_to_tombstone = (log->tfd != -1);
+  bool write_to_logcat = is_allowed_in_logcat(ltype)
+                      && log->crashed_tid != -1
+                      && log->current_tid != -1
+                      && (log->crashed_tid == log->current_tid);
+  bool write_to_activitymanager = (log->amfd != -1);
 
   char buf[512];
   va_list ap;
@@ -60,13 +75,13 @@ void _LOG(log_t* log, int scopeFlags, const char* fmt, ...) {
     return;
   }
 
-  if (want_tfd_write) {
+  if (write_to_tombstone) {
     TEMP_FAILURE_RETRY(write(log->tfd, buf, len));
   }
 
-  if (want_log_write) {
-    __android_log_buf_write(LOG_ID_CRASH, ANDROID_LOG_INFO, "DEBUG", buf);
-    if (want_amfd_write) {
+  if (write_to_logcat) {
+    __android_log_buf_write(LOG_ID_CRASH, ANDROID_LOG_INFO, LOG_TAG, buf);
+    if (write_to_activitymanager) {
       int written = write_to_am(log->amfd, buf, len);
       if (written <= 0) {
         // timeout or other failure on write; stop informing the activity manager
@@ -76,48 +91,44 @@ void _LOG(log_t* log, int scopeFlags, const char* fmt, ...) {
   }
 }
 
-int wait_for_signal(pid_t tid, int* total_sleep_time_usec) {
+int wait_for_sigstop(pid_t tid, int* total_sleep_time_usec, bool* detach_failed) {
+  bool allow_dead_tid = false;
   for (;;) {
     int status;
-    pid_t n = waitpid(tid, &status, __WALL | WNOHANG);
-    if (n < 0) {
-      if (errno == EAGAIN)
-        continue;
-      LOG("waitpid failed: %s\n", strerror(errno));
-      return -1;
-    } else if (n > 0) {
-      XLOG("waitpid: n=%d status=%08x\n", n, status);
+    pid_t n = TEMP_FAILURE_RETRY(waitpid(tid, &status, __WALL | WNOHANG));
+    if (n == -1) {
+      ALOGE("waitpid failed: tid %d, %s", tid, strerror(errno));
+      break;
+    } else if (n == tid) {
       if (WIFSTOPPED(status)) {
         return WSTOPSIG(status);
       } else {
-        LOG("unexpected waitpid response: n=%d, status=%08x\n", n, status);
-        return -1;
+        ALOGE("unexpected waitpid response: n=%d, status=%08x\n", n, status);
+        // This is the only circumstance under which we can allow a detach
+        // to fail with ESRCH, which indicates the tid has exited.
+        allow_dead_tid = true;
+        break;
       }
     }
 
-    if (*total_sleep_time_usec > max_total_sleep_usec) {
-      LOG("timed out waiting for tid=%d to die\n", tid);
-      return -1;
+    if (*total_sleep_time_usec > MAX_TOTAL_SLEEP_USEC) {
+      ALOGE("timed out waiting for stop signal: tid=%d", tid);
+      break;
     }
 
-    // not ready yet
-    XLOG("not ready yet\n");
-    usleep(sleep_time_usec);
-    *total_sleep_time_usec += sleep_time_usec;
+    usleep(SLEEP_TIME_USEC);
+    *total_sleep_time_usec += SLEEP_TIME_USEC;
   }
-}
 
-void wait_for_stop(pid_t tid, int* total_sleep_time_usec) {
-  siginfo_t si;
-  while (TEMP_FAILURE_RETRY(ptrace(PTRACE_GETSIGINFO, tid, 0, &si)) < 0 && errno == ESRCH) {
-    if (*total_sleep_time_usec > max_total_sleep_usec) {
-      LOG("timed out waiting for tid=%d to stop\n", tid);
-      break;
+  if (ptrace(PTRACE_DETACH, tid, 0, 0) != 0) {
+    if (allow_dead_tid && errno == ESRCH) {
+      ALOGE("tid exited before attach completed: tid %d", tid);
+    } else {
+      *detach_failed = true;
+      ALOGE("detach failed: tid %d, %s", tid, strerror(errno));
     }
-
-    usleep(sleep_time_usec);
-    *total_sleep_time_usec += sleep_time_usec;
   }
+  return -1;
 }
 
 #if defined (__mips__)
@@ -126,7 +137,7 @@ void wait_for_stop(pid_t tid, int* total_sleep_time_usec) {
 #define DUMP_MEMORY_AS_ASCII 0
 #endif
 
-void dump_memory(log_t* log, pid_t tid, uintptr_t addr, int scope_flags) {
+void dump_memory(log_t* log, pid_t tid, uintptr_t addr) {
     char code_buffer[64];
     char ascii_buffer[32];
     uintptr_t p, end;
@@ -190,6 +201,6 @@ void dump_memory(log_t* log, pid_t tid, uintptr_t addr, int scope_flags) {
             p += sizeof(long);
         }
         *asc_out = '\0';
-        _LOG(log, scope_flags, "    %s %s\n", code_buffer, ascii_buffer);
+        _LOG(log, logtype::MEMORY, "    %s %s\n", code_buffer, ascii_buffer);
     }
 }