commit 32150288f88b2a1a6e7268b24cd8b2646b1af5d6
author Steven Moreland <smoreland@google.com> Fri Nov 12 22:54:53 2021 +0000
committer Andrei Homescu <ahomescu@google.com> Fri Jul 01 05:50:52 2022 +0000
tree 4dab826b41b4fec3fb19ed9d4aa2be1364d300f0
parent ffa3aaac5513bc2ef6c7d3f88db9976f86275f88

libbinder: build option to disable the kernel IPC, part 1/2

Add a new BINDER_WITH_KERNEL_IPC macro to enable all code that
uses IPCThreadState or ProcessState. This macro is defined for
Android libbinder but left out for non-Android builds.

Bug: 224644083
Test: m
Change-Id: I622757fcc0f9885dbf271c0ffa84c54938d50774

libs/binder/BpBinder.cpp

diff --git a/libs/binder/BpBinder.cpp b/libs/binder/BpBinder.cpp
index 1eb2ffd..49fc195 100644
--- a/libs/binder/BpBinder.cpp
+++ b/libs/binder/BpBinder.cpp
@@ -28,6 +28,8 @@
 
 #include <stdio.h>
 
+#include "BuildFlags.h"
+
 //#undef ALOGV
 //#define ALOGV(...) fprintf(stderr, __VA_ARGS__)
 
@@ -115,6 +117,11 @@
 // ---------------------------------------------------------------------------
 
 sp<BpBinder> BpBinder::create(int32_t handle) {
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return nullptr;
+    }
+
     int32_t trackedUid = -1;
     if (sCountByUidEnabled) {
         trackedUid = IPCThreadState::self()->getCallingUid();
@@ -177,6 +184,11 @@
 }
 
 BpBinder::BpBinder(BinderHandle&& handle, int32_t trackedUid) : BpBinder(Handle(handle)) {
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return;
+    }
+
     mTrackedUid = trackedUid;
 
     ALOGV("Creating BpBinder %p handle %d\n", this, this->binderHandle());
@@ -303,6 +315,11 @@
             status = rpcSession()->transact(sp<IBinder>::fromExisting(this), code, data, reply,
                                             flags);
         } else {
+            if constexpr (!kEnableKernelIpc) {
+                LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+                return INVALID_OPERATION;
+            }
+
             status = IPCThreadState::self()->transact(binderHandle(), code, data, reply, flags);
         }
         if (data.dataSize() > LOG_TRANSACTIONS_OVER_SIZE) {
@@ -328,6 +345,11 @@
 {
     if (isRpcBinder()) return UNKNOWN_TRANSACTION;
 
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return INVALID_OPERATION;
+    }
+
     Obituary ob;
     ob.recipient = recipient;
     ob.cookie = cookie;
@@ -366,6 +388,11 @@
 {
     if (isRpcBinder()) return UNKNOWN_TRANSACTION;
 
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return INVALID_OPERATION;
+    }
+
     AutoMutex _l(mLock);
 
     if (mObitsSent) {
@@ -401,6 +428,11 @@
 {
     LOG_ALWAYS_FATAL_IF(isRpcBinder(), "Cannot send obituary for remote binder.");
 
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return;
+    }
+
     ALOGV("Sending obituary for proxy %p handle %d, mObitsSent=%s\n", this, binderHandle(),
           mObitsSent ? "true" : "false");
 
@@ -469,12 +501,16 @@
     return this;
 }
 
-BpBinder::~BpBinder()
-{
-    ALOGV("Destroying BpBinder %p handle %d\n", this, binderHandle());
-
+BpBinder::~BpBinder() {
     if (CC_UNLIKELY(isRpcBinder())) return;
 
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return;
+    }
+
+    ALOGV("Destroying BpBinder %p handle %d\n", this, binderHandle());
+
     IPCThreadState* ipc = IPCThreadState::self();
 
     if (mTrackedUid >= 0) {
@@ -505,21 +541,31 @@
     }
 }
 
-void BpBinder::onFirstRef()
-{
-    ALOGV("onFirstRef BpBinder %p handle %d\n", this, binderHandle());
+void BpBinder::onFirstRef() {
     if (CC_UNLIKELY(isRpcBinder())) return;
+
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return;
+    }
+
+    ALOGV("onFirstRef BpBinder %p handle %d\n", this, binderHandle());
     IPCThreadState* ipc = IPCThreadState::self();
     if (ipc) ipc->incStrongHandle(binderHandle(), this);
 }
 
-void BpBinder::onLastStrongRef(const void* /*id*/)
-{
-    ALOGV("onLastStrongRef BpBinder %p handle %d\n", this, binderHandle());
+void BpBinder::onLastStrongRef(const void* /*id*/) {
     if (CC_UNLIKELY(isRpcBinder())) {
         (void)rpcSession()->sendDecStrong(this);
         return;
     }
+
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return;
+    }
+
+    ALOGV("onLastStrongRef BpBinder %p handle %d\n", this, binderHandle());
     IF_ALOGV() {
         printRefs();
     }
@@ -552,6 +598,11 @@
     // RPC binder doesn't currently support inc from weak binders
     if (CC_UNLIKELY(isRpcBinder())) return false;
 
+    if constexpr (!kEnableKernelIpc) {
+        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");
+        return false;
+    }
+
     ALOGV("onIncStrongAttempted BpBinder %p handle %d\n", this, binderHandle());
     IPCThreadState* ipc = IPCThreadState::self();
     return ipc ? ipc->attemptIncStrongHandle(binderHandle()) == NO_ERROR : false;