commit 7ee17575d3cc8c7c9c08dc87b9932bd74f251ec1
author Marco Ballesio <balejs@google.com> Tue Sep 08 10:30:03 2020 -0700
committer Marco Ballesio <balejs@google.com> Wed Sep 09 04:52:21 2020 +0000
tree b5be0f9e522204bf3c2958974c863adfbd932a30
parent b92b235aaa95e11dc83b39628e19427998dfb240

binder: adopt BINDER_FREEZE api

The BINDER_FREEZE ioctl and related structures have been added to the
driver to notify binder of the frozen state of a process. This patch
introduces low-level user space handling for libbinder.

Bug: 143717177
Test: verified that binder transactions to a frozen app return ERR_FROZEN
Test: verified that transactions are correctly received by non-frozen apps

Co-developed-by: Todd Kjos <tkjos@google.com>
Change-Id: I31fed5ecb040f5ba5b8e27ab6a20c441964f32b4

libs/binder/IPCThreadState.cpp

diff --git a/libs/binder/IPCThreadState.cpp b/libs/binder/IPCThreadState.cpp
index 9aaca65..0c71ed8 100644
--- a/libs/binder/IPCThreadState.cpp
+++ b/libs/binder/IPCThreadState.cpp
@@ -860,6 +860,10 @@
             err = FAILED_TRANSACTION;
             goto finish;
 
+        case BR_FROZEN_REPLY:
+            err = FAILED_TRANSACTION;
+            goto finish;
+
         case BR_ACQUIRE_RESULT:
             {
                 ALOG_ASSERT(acquireResult != NULL, "Unexpected brACQUIRE_RESULT");
@@ -1316,6 +1320,26 @@
         }
 }
 
+status_t IPCThreadState::freeze(pid_t pid, bool enable, uint32_t timeout_ms) {
+    struct binder_freeze_info info;
+    int ret = 0;
+
+    info.pid = pid;
+    info.enable = enable;
+    info.timeout_ms = timeout_ms;
+
+
+#if defined(__ANDROID__)
+    if (ioctl(self()->mProcess->mDriverFD, BINDER_FREEZE, &info) < 0)
+        ret = -errno;
+#endif
+
+    //
+    // ret==-EAGAIN indicates that transactions have not drained.
+    // Call again to poll for completion.
+    //
+    return ret;
+}
 
 void IPCThreadState::freeBuffer(Parcel* parcel, const uint8_t* data,
                                 size_t /*dataSize*/,