5 files changed, 25 insertions, 1 deletions
diff --git a/linker/debugger.cpp b/linker/debugger.cpp
index c889544d1..6fe9524e7 100644
--- a/linker/debugger.cpp
+++ b/linker/debugger.cpp
@@ -30,9 +30,11 @@
 
 #include <errno.h>
 #include <inttypes.h>
+#include <pthread.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/prctl.h>
 #include <sys/socket.h>
@@ -212,6 +214,23 @@ static void send_debuggerd_packet(siginfo_t* info) {
     return;
   }
 
+  // Mutex to prevent multiple crashing threads from trying to talk
+  // to debuggerd at the same time.
+  static pthread_mutex_t crash_mutex = PTHREAD_MUTEX_INITIALIZER;
+  int ret = pthread_mutex_trylock(&crash_mutex);
+  if (ret != 0) {
+    if (ret == EBUSY) {
+      __libc_format_log(ANDROID_LOG_INFO, "libc",
+                        "Another thread has contacted debuggerd first, stop and wait for process to die.");
+      // This will never complete since the lock is never released.
+      pthread_mutex_lock(&crash_mutex);
+    } else {
+      __libc_format_log(ANDROID_LOG_INFO, "libc",
+                        "pthread_mutex_trylock failed: %s", strerror(ret));
+    }
+    return;
+  }
+
   int s = socket_abstract_client(DEBUGGER_SOCKET_NAME, SOCK_STREAM | SOCK_CLOEXEC);
   if (s == -1) {
     __libc_format_log(ANDROID_LOG_FATAL, "libc", "Unable to open connection to debuggerd: %s",
@@ -228,7 +247,7 @@ static void send_debuggerd_packet(siginfo_t* info) {
   msg.tid = gettid();
   msg.abort_msg_address = reinterpret_cast<uintptr_t>(g_abort_message);
   msg.original_si_code = (info != nullptr) ? info->si_code : 0;
-  int ret = TEMP_FAILURE_RETRY(write(s, &msg, sizeof(msg)));
+  ret = TEMP_FAILURE_RETRY(write(s, &msg, sizeof(msg)));
   if (ret == sizeof(msg)) {
     char debuggerd_ack;
     ret = TEMP_FAILURE_RETRY(read(s, &debuggerd_ack, 1));
diff --git a/linker/dlfcn.cpp b/linker/dlfcn.cpp
index 7ef94c059..9a8dbc93f 100644
--- a/linker/dlfcn.cpp
+++ b/linker/dlfcn.cpp
@@ -20,6 +20,7 @@
 #include <pthread.h>
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
 #include <android/dlext.h>
 
 #include <bionic/pthread_internal.h>
diff --git a/linker/linker_allocator.cpp b/linker/linker_allocator.cpp
index 92220e8c4..ac11b979a 100644
--- a/linker/linker_allocator.cpp
+++ b/linker/linker_allocator.cpp
@@ -13,8 +13,10 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
+
 #include "linker_allocator.h"
 #include <inttypes.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <unistd.h>
 
diff --git a/linker/linker_environ.cpp b/linker/linker_environ.cpp
index daee56f7e..7272f4e83 100644
--- a/linker/linker_environ.cpp
+++ b/linker/linker_environ.cpp
@@ -31,6 +31,7 @@
 #include <linux/auxvec.h>
 #include <stddef.h>
 #include <stdlib.h>
+#include <string.h>
 #include <unistd.h>
 
 #include "private/KernelArgumentBlock.h"
diff --git a/linker/linker_phdr.cpp b/linker/linker_phdr.cpp
index af4dc2567..91a2fb80d 100644
--- a/linker/linker_phdr.cpp
+++ b/linker/linker_phdr.cpp
@@ -29,6 +29,7 @@
 #include "linker_phdr.h"
 
 #include <errno.h>
+#include <string.h>
 #include <sys/mman.h>
 #include <sys/types.h>
 #include <sys/stat.h>