commit 9f20f3cff9ead8efbbcab19b2841362a0e3789ab
author Pavlin Radoslavov <pavlin@google.com> Wed May 18 14:34:31 2016 -0700
committer Andre Eisenbach <eisenbach@google.com> Thu May 19 20:57:02 2016 +0000
tree 2fd3cb671d0ba7cb1b506777cb1632b69edd3f65
parent a7373c8f031a68a52ce1f876457d1c5c74aaa87f

Improve poll(2) handling and log messages

 * Better error handling and log messages inside
   uipc_flush_ch_locked()
 * Add missing error check inside UIPC_Read()
 * Add missing OSI_NO_INTR() wrapper around poll()
   inside function btu_exec_tap_fd_read()

Bug: 28823662
Change-Id: I5f1c720861bea594d53ed6465a5ff327ba352598

btif/src/btif_pan.cc

diff --git a/btif/src/btif_pan.cc b/btif/src/btif_pan.cc
index fe6bdbd..1eef784 100644
--- a/btif/src/btif_pan.cc
+++ b/btif/src/btif_pan.cc
@@ -787,7 +787,10 @@
         ufd.fd = fd;
         ufd.events = POLLIN;
         ufd.revents = 0;
-        if (poll(&ufd, 1, 0) <= 0 || IS_EXCEPTION(ufd.revents))
+
+        int ret;
+        OSI_NO_INTR(ret = poll(&ufd, 1, 0));
+        if (ret <= 0 || IS_EXCEPTION(ufd.revents))
             break;
     }
 

udrv/ulinux/uipc.c

diff --git a/udrv/ulinux/uipc.c b/udrv/ulinux/uipc.c
index c9ff0f1..66b26d5 100644
--- a/udrv/ulinux/uipc.c
+++ b/udrv/ulinux/uipc.c
@@ -394,6 +394,16 @@
     {
         int ret;
         OSI_NO_INTR(ret = poll(&pfd, 1, 1));
+        if (ret == 0) {
+            BTIF_TRACE_VERBOSE("%s(): poll() timeout - nothing to do. Exiting",
+                               __func__);
+            return;
+        }
+        if (ret < 0) {
+            BTIF_TRACE_WARNING("%s() - poll() failed: return %d errno %d (%s). Exiting",
+                               __func__, ret, errno, strerror(errno));
+            return;
+        }
         BTIF_TRACE_VERBOSE("%s() - polling fd %d, revents: 0x%x, ret %d",
                 __FUNCTION__, pfd.fd, pfd.revents, ret);
         if (pfd.revents & (POLLERR|POLLHUP))
@@ -402,13 +412,6 @@
             return;
         }
 
-        if (ret <= 0)
-        {
-            BTIF_TRACE_WARNING("%s() - poll() failed (%s). Exiting",
-                               __FUNCTION__, strerror(errno));
-            return;
-        }
-
         /* read sufficiently large buffer to ensure flush empties socket faster than
            it is getting refilled */
         read(pfd.fd, &buf, UIPC_FLUSH_BUFFER_SIZE);
@@ -747,6 +750,11 @@
             BTIF_TRACE_WARNING("poll timeout (%d ms)", uipc_main.ch[ch_id].read_poll_tmo_ms);
             break;
         }
+        if (poll_ret < 0) {
+            BTIF_TRACE_ERROR("%s(): poll() failed: return %d errno %d (%s)",
+                           __func__, poll_ret, errno, strerror(errno));
+            break;
+        }
 
         //BTIF_TRACE_EVENT("poll revents %x", pfd.revents);