libbinder: support inheriting realtime priority
gotta go fast
Bug: 170420170
Test: atest binderLibTest
Change-Id: I2f2c6cb35ebf463d90b517e134b9ea3114764af6
diff --git a/libs/binder/Binder.cpp b/libs/binder/Binder.cpp
index f2d223d..d964d25 100644
--- a/libs/binder/Binder.cpp
+++ b/libs/binder/Binder.cpp
@@ -133,6 +133,7 @@
public:
// unlocked objects
bool mRequestingSid = false;
+ bool mInheritRt = false;
sp<IBinder> mExtension;
int mPolicy = SCHED_NORMAL;
int mPriority = 0;
@@ -327,6 +328,27 @@
return e->mPriority;
}
+bool BBinder::isInheritRt() {
+ Extras* e = mExtras.load(std::memory_order_acquire);
+
+ return e && e->mInheritRt;
+}
+
+void BBinder::setInheritRt(bool inheritRt) {
+ Extras* e = mExtras.load(std::memory_order_acquire);
+
+ if (!e) {
+ if (!inheritRt) {
+ return;
+ }
+
+ e = getOrCreateExtras();
+ if (!e) return; // out of memory
+ }
+
+ e->mInheritRt = inheritRt;
+}
+
pid_t BBinder::getDebugPid() {
return getpid();
}
diff --git a/libs/binder/Parcel.cpp b/libs/binder/Parcel.cpp
index a7d8df2..3330a2e 100644
--- a/libs/binder/Parcel.cpp
+++ b/libs/binder/Parcel.cpp
@@ -222,6 +222,9 @@
if (local->isRequestingSid()) {
obj.flags |= FLAT_BINDER_FLAG_TXN_SECURITY_CTX;
}
+ if (local->isInheritRt()) {
+ obj.flags |= FLAT_BINDER_FLAG_INHERIT_RT;
+ }
obj.hdr.type = BINDER_TYPE_BINDER;
obj.binder = reinterpret_cast<uintptr_t>(local->getWeakRefs());
obj.cookie = reinterpret_cast<uintptr_t>(local);
diff --git a/libs/binder/include/binder/Binder.h b/libs/binder/include/binder/Binder.h
index d6da397..7079544 100644
--- a/libs/binder/include/binder/Binder.h
+++ b/libs/binder/include/binder/Binder.h
@@ -87,6 +87,11 @@
int getMinSchedulerPolicy();
int getMinSchedulerPriority();
+ // Whether realtime scheduling policies are inherited.
+ bool isInheritRt();
+ // This must be called before the object is sent to another process. Not thread safe.
+ void setInheritRt(bool inheritRt);
+
pid_t getDebugPid();
protected:
diff --git a/libs/binder/tests/binderLibTest.cpp b/libs/binder/tests/binderLibTest.cpp
index ad4729d..0f7d159 100644
--- a/libs/binder/tests/binderLibTest.cpp
+++ b/libs/binder/tests/binderLibTest.cpp
@@ -30,6 +30,7 @@
#include <binder/IServiceManager.h>
#include <private/binder/binder_module.h>
+#include <linux/sched.h>
#include <sys/epoll.h>
#include <sys/prctl.h>
@@ -53,6 +54,7 @@
static constexpr int kSchedPolicy = SCHED_RR;
static constexpr int kSchedPriority = 7;
+static constexpr int kSchedPriorityMore = 8;
static String16 binderLibTestServiceName = String16("test.binderLib");
@@ -1088,6 +1090,25 @@
EXPECT_EQ(kSchedPriority, priority);
}
+TEST_F(BinderLibTest, InheritRt) {
+ sp<IBinder> server = addServer();
+ ASSERT_TRUE(server != nullptr);
+
+ const struct sched_param param {
+ .sched_priority = kSchedPriorityMore,
+ };
+ EXPECT_EQ(0, sched_setscheduler(getpid(), SCHED_RR, ¶m));
+
+ Parcel data, reply;
+ status_t ret = server->transact(BINDER_LIB_TEST_GET_SCHEDULING_POLICY, data, &reply);
+ EXPECT_EQ(NO_ERROR, ret);
+
+ int policy = reply.readInt32();
+ int priority = reply.readInt32();
+
+ EXPECT_EQ(kSchedPolicy, policy & (~SCHED_RESET_ON_FORK));
+ EXPECT_EQ(kSchedPriorityMore, priority);
+}
TEST_F(BinderLibTest, VectorSent) {
Parcel data, reply;
@@ -1460,6 +1481,8 @@
testService->setMinSchedulerPolicy(kSchedPolicy, kSchedPriority);
+ testService->setInheritRt(true);
+
/*
* Normally would also contain functionality as well, but we are only
* testing the extension mechanism.
diff --git a/libs/binder/tests/fuzzers/BinderFuzzFunctions.h b/libs/binder/tests/fuzzers/BinderFuzzFunctions.h
index 9ac65bb..69f1b9d 100644
--- a/libs/binder/tests/fuzzers/BinderFuzzFunctions.h
+++ b/libs/binder/tests/fuzzers/BinderFuzzFunctions.h
@@ -37,8 +37,8 @@
bbinder->isRequestingSid();
},
[](FuzzedDataProvider* fdp, const sp<BBinder>& bbinder) -> void {
- bool request_sid = fdp->ConsumeBool();
- bbinder->setRequestingSid(request_sid);
+ bool requestSid = fdp->ConsumeBool();
+ bbinder->setRequestingSid(requestSid);
},
[](FuzzedDataProvider*, const sp<BBinder>& bbinder) -> void {
bbinder->getExtension();
@@ -63,6 +63,13 @@
[](FuzzedDataProvider*, const sp<BBinder>& bbinder) -> void {
bbinder->getMinSchedulerPriority();
},
+ [](FuzzedDataProvider* fdp, const sp<BBinder>& bbinder) -> void {
+ bool inheritRt = fdp->ConsumeBool();
+ bbinder->setInheritRt(inheritRt);
+ },
+ [](FuzzedDataProvider*, const sp<BBinder>& bbinder) -> void {
+ bbinder->isInheritRt();
+ },
[](FuzzedDataProvider*, const sp<BBinder>& bbinder) -> void {
bbinder->getDebugPid();
}};