commit cbb65ae216a47a080c2ff301b593f86d7ac2c1a2
author Josh Gao <jmgao@google.com> Mon Mar 20 11:33:34 2017 -0700
committer Josh Gao <jmgao@google.com> Mon Mar 20 14:01:02 2017 -0700
tree 7ceeafe366776d5c63d9978c188e4a8efcd33ca2
parent 46ef4a6f7f59f65c77ef99d4a8d9fcd6d6d3ef0b

jdwp: switch to SOCK_SEQPACKET.

When sending the process's PID to adbd, we use
TEMP_FAILURE_RETRY(send(...)), and check if the result is non-negative.
However, this could theoretically return short, leaving adbd waiting
for the rest of the PID. Switch the socket to a SOCK_SEQPACKET to
sidestep all of this.

Bug: http://b/36411868
Test: adb jdwp
Change-Id: I0ec75912ac579868f77554e3c6db23c7ab95a34c

runtime/jdwp/jdwp_adb.cc

diff --git a/runtime/jdwp/jdwp_adb.cc b/runtime/jdwp/jdwp_adb.cc
index b13d565..0aa04c1 100644
--- a/runtime/jdwp/jdwp_adb.cc
+++ b/runtime/jdwp/jdwp_adb.cc
@@ -227,7 +227,7 @@
     const int  sleep_max_ms = 2*1000;
     char       buff[5];
 
-    int sock = socket(PF_UNIX, SOCK_STREAM, 0);
+    int sock = socket(AF_UNIX, SOCK_SEQPACKET, 0);
     if (sock < 0) {
       PLOG(ERROR) << "Could not create ADB control socket";
       return false;
@@ -264,7 +264,7 @@
        * up after a few minutes in case somebody ships an app with
        * the debuggable flag set.
        */
-      int  ret = connect(ControlSock(), &control_addr_.controlAddrPlain, control_addr_len_);
+      int ret = connect(ControlSock(), &control_addr_.controlAddrPlain, control_addr_len_);
       if (!ret) {
         int control_sock = ControlSock();
 #ifdef ART_TARGET_ANDROID
@@ -278,7 +278,7 @@
 
         /* now try to send our pid to the ADB daemon */
         ret = TEMP_FAILURE_RETRY(send(control_sock, buff, 4, 0));
-        if (ret >= 0) {
+        if (ret == 4) {
           VLOG(jdwp) << StringPrintf("PID sent as '%.*s' to ADB", 4, buff);
           break;
         }