Revert^2 "libbinder: binder RPC - using getCalling* aborts"

15e2835588ce3a8e318c01230bda2c113a16f761

Broken code? Now you know!

Fixes: 186647790
Test: binderRpcTest (on host and device)

Change-Id: I994b007b76d68771519dc8279534616ec60e9d71

1 files changed, 19 insertions, 0 deletions

diff --git a/libs/binder/RpcState.cpp b/libs/binder/RpcState.cpp
index 2ba9fa2bd5..230de6f0ef 100644
--- a/libs/binder/RpcState.cpp
+++ b/libs/binder/RpcState.cpp
@@ -18,7 +18,9 @@
 
 #include "RpcState.h"
 
+#include <android-base/scopeguard.h>
 #include <binder/BpBinder.h>
+#include <binder/IPCThreadState.h>
 #include <binder/RpcServer.h>
 
 #include "Debug.h"
@@ -28,6 +30,8 @@
 
 namespace android {
 
+using base::ScopeGuard;
+
 RpcState::RpcState() {}
 RpcState::~RpcState() {}
 
@@ -470,6 +474,21 @@ status_t RpcState::getAndExecuteCommand(const base::unique_fd& fd, const sp<RpcS
 
 status_t RpcState::processServerCommand(const base::unique_fd& fd, const sp<RpcSession>& session,
                                         const RpcWireHeader& command) {
+    IPCThreadState* kernelBinderState = IPCThreadState::selfOrNull();
+    IPCThreadState::SpGuard spGuard{
+            .address = __builtin_frame_address(0),
+            .context = "processing binder RPC command",
+    };
+    const IPCThreadState::SpGuard* origGuard;
+    if (kernelBinderState != nullptr) {
+        origGuard = kernelBinderState->pushGetCallingSpGuard(&spGuard);
+    }
+    ScopeGuard guardUnguard = [&]() {
+        if (kernelBinderState != nullptr) {
+            kernelBinderState->restoreGetCallingSpGuard(origGuard);
+        }
+    };
+
     switch (command.command) {
         case RPC_COMMAND_TRANSACT:
             return processTransact(fd, session, command);