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Commit a9cca9cb authored by Andrei Homescu's avatar Andrei Homescu
Browse files

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

Use BINDER_KERNEL_IPC to disable all code that
uses flat_binder_object in Parcel.cpp.

Bug: 224644083
Test: m
Change-Id: I1f676dbfb464fc0c5eaa6b5266b7af1dabe984e1
parent 32150288

libs/binder/Parcel.cpp

+107 −4
Original line number Diff line number Diff line
@@ -20,15 +20,14 @@ 
#include <errno.h>

#include <fcntl.h>

#include <inttypes.h>

#include <linux/sched.h>

#include <pthread.h>

#include <stdint.h>

#include <stdio.h>

#include <stdlib.h>

#include <sys/mman.h>

#include <sys/resource.h>

#include <sys/stat.h>

#include <sys/types.h>

#include <sys/resource.h>

#include <unistd.h>



#include <binder/Binder.h>
@@ -52,7 +51,22 @@ 
#include "RpcState.h"

#include "Static.h"

#include "Utils.h"



// A lot of code in this file uses definitions from the

// Linux kernel header for Binder <linux/android/binder.h>

// which is included indirectly via "binder_module.h".

// Non-Linux OSes do not have that header, so libbinder should be

// built for those targets without kernel binder support, i.e.,

// without BINDER_WITH_KERNEL_IPC. For this reason, all code in this

// file that depends on kernel binder, including the header itself,

// is conditional on BINDER_WITH_KERNEL_IPC.

#ifdef BINDER_WITH_KERNEL_IPC

#include <linux/sched.h>

#include "binder_module.h"

#else  // BINDER_WITH_KERNEL_IPC

// Needed by {read,write}Pointer

typedef uintptr_t binder_uintptr_t;

#endif // BINDER_WITH_KERNEL_IPC



#define LOG_REFS(...)

// #define LOG_REFS(...) ALOG(LOG_DEBUG, LOG_TAG, __VA_ARGS__)
@@ -100,6 +114,7 @@ enum { 
    BLOB_ASHMEM_MUTABLE = 2,

};



#ifdef BINDER_WITH_KERNEL_IPC

static void acquire_object(const sp<ProcessState>& proc, const flat_binder_object& obj,

                           const void* who) {

    switch (obj.hdr.type) {
@@ -152,6 +167,7 @@ static void release_object(const sp<ProcessState>& proc, const flat_binder_objec 


    ALOGE("Invalid object type 0x%08x", obj.hdr.type);

}

#endif // BINDER_WITH_KERNEL_IPC



static int toRawFd(const std::variant<base::unique_fd, base::borrowed_fd>& v) {

    return std::visit([](const auto& fd) { return fd.get(); }, v);
@@ -183,9 +199,11 @@ status_t Parcel::finishUnflattenBinder( 
    return OK;

}



#ifdef BINDER_WITH_KERNEL_IPC

static constexpr inline int schedPolicyMask(int policy, int priority) {

    return (priority & FLAT_BINDER_FLAG_PRIORITY_MASK) | ((policy & 3) << FLAT_BINDER_FLAG_SCHED_POLICY_SHIFT);

}

#endif // BINDER_WITH_KERNEL_IPC



status_t Parcel::flattenBinder(const sp<IBinder>& binder) {

    BBinder* local = nullptr;
@@ -210,6 +228,7 @@ status_t Parcel::flattenBinder(const sp<IBinder>& binder) { 
        return finishFlattenBinder(binder);

    }



#ifdef BINDER_WITH_KERNEL_IPC

    flat_binder_object obj;



    int schedBits = 0;
@@ -266,6 +285,10 @@ status_t Parcel::flattenBinder(const sp<IBinder>& binder) { 
    if (status != OK) return status;



    return finishFlattenBinder(binder);

#else  // BINDER_WITH_KERNEL_IPC

    LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

    return INVALID_OPERATION;

#endif // BINDER_WITH_KERNEL_IPC

}



status_t Parcel::unflattenBinder(sp<IBinder>* out) const
@@ -295,6 +318,7 @@ status_t Parcel::unflattenBinder(sp<IBinder>* out) const 
        return finishUnflattenBinder(binder, out);

    }



#ifdef BINDER_WITH_KERNEL_IPC

    const flat_binder_object* flat = readObject(false);



    if (flat) {
@@ -312,6 +336,10 @@ status_t Parcel::unflattenBinder(sp<IBinder>* out) const 
        }

    }

    return BAD_TYPE;

#else  // BINDER_WITH_KERNEL_IPC

    LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

    return INVALID_OPERATION;

#endif // BINDER_WITH_KERNEL_IPC

}



// ---------------------------------------------------------------------------
@@ -475,6 +503,7 @@ status_t Parcel::appendFrom(const Parcel* parcel, size_t offset, size_t len) { 


    err = NO_ERROR;



#ifdef BINDER_WITH_KERNEL_IPC

    if (auto* kernelFields = maybeKernelFields()) {

        auto* otherKernelFields = parcel->maybeKernelFields();

        LOG_ALWAYS_FATAL_IF(otherKernelFields == nullptr);
@@ -593,6 +622,7 @@ status_t Parcel::appendFrom(const Parcel* parcel, size_t offset, size_t len) { 
            }

        }

    }

#endif // BINDER_WITH_KERNEL_IPC



    return err;

}
@@ -658,6 +688,7 @@ bool Parcel::hasFileDescriptors() const 
std::vector<sp<IBinder>> Parcel::debugReadAllStrongBinders() const {

    std::vector<sp<IBinder>> ret;



#ifdef BINDER_WITH_KERNEL_IPC

    const auto* kernelFields = maybeKernelFields();

    if (kernelFields == nullptr) {

        return ret;
@@ -677,6 +708,8 @@ std::vector<sp<IBinder>> Parcel::debugReadAllStrongBinders() const { 
    }



    setDataPosition(initPosition);

#endif // BINDER_WITH_KERNEL_IPC



    return ret;

}
@@ -684,6 +717,7 @@ std::vector<int> Parcel::debugReadAllFileDescriptors() const { 
    std::vector<int> ret;



    if (const auto* kernelFields = maybeKernelFields()) {

#ifdef BINDER_WITH_KERNEL_IPC

        size_t initPosition = dataPosition();

        for (size_t i = 0; i < kernelFields->mObjectsSize; i++) {

            binder_size_t offset = kernelFields->mObjects[i];
@@ -698,6 +732,9 @@ std::vector<int> Parcel::debugReadAllFileDescriptors() const { 
            ret.push_back(fd);

        }

        setDataPosition(initPosition);

#else

        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

#endif

    } else if (const auto* rpcFields = maybeRpcFields(); rpcFields && rpcFields->mFds) {

        for (const auto& fd : *rpcFields->mFds) {

            ret.push_back(toRawFd(fd));
@@ -719,6 +756,7 @@ status_t Parcel::hasFileDescriptorsInRange(size_t offset, size_t len, bool* resu 
    }

    *result = false;

    if (const auto* kernelFields = maybeKernelFields()) {

#ifdef BINDER_WITH_KERNEL_IPC

        for (size_t i = 0; i < kernelFields->mObjectsSize; i++) {

            size_t pos = kernelFields->mObjects[i];

            if (pos < offset) continue;
@@ -736,6 +774,10 @@ status_t Parcel::hasFileDescriptorsInRange(size_t offset, size_t len, bool* resu 
                break;

            }

        }

#else

        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

        return INVALID_OPERATION;

#endif // BINDER_WITH_KERNEL_IPC

    } else if (const auto* rpcFields = maybeRpcFields()) {

        for (uint32_t pos : rpcFields->mObjectPositions) {

            if (offset <= pos && pos < limit) {
@@ -788,6 +830,7 @@ void Parcel::updateWorkSourceRequestHeaderPosition() const { 
    }

}



#ifdef BINDER_WITH_KERNEL_IPC

#if defined(__ANDROID_VNDK__)

constexpr int32_t kHeader = B_PACK_CHARS('V', 'N', 'D', 'R');

#elif defined(__ANDROID_RECOVERY__)
@@ -795,6 +838,7 @@ constexpr int32_t kHeader = B_PACK_CHARS('R', 'E', 'C', 'O'); 
#else

constexpr int32_t kHeader = B_PACK_CHARS('S', 'Y', 'S', 'T');

#endif

#endif // BINDER_WITH_KERNEL_IPC



// Write RPC headers.  (previously just the interface token)

status_t Parcel::writeInterfaceToken(const String16& interface)
@@ -804,12 +848,17 @@ status_t Parcel::writeInterfaceToken(const String16& interface) 


status_t Parcel::writeInterfaceToken(const char16_t* str, size_t len) {

    if (auto* kernelFields = maybeKernelFields()) {

#ifdef BINDER_WITH_KERNEL_IPC

        const IPCThreadState* threadState = IPCThreadState::self();

        writeInt32(threadState->getStrictModePolicy() | STRICT_MODE_PENALTY_GATHER);

        updateWorkSourceRequestHeaderPosition();

        writeInt32(threadState->shouldPropagateWorkSource() ? threadState->getCallingWorkSourceUid()

                                                            : IPCThreadState::kUnsetWorkSource);

        writeInt32(kHeader);

#else  // BINDER_WITH_KERNEL_IPC

        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

        return INVALID_OPERATION;

#endif // BINDER_WITH_KERNEL_IPC

    }



    // currently the interface identification token is just its name as a string
@@ -866,6 +915,7 @@ bool Parcel::enforceInterface(const char16_t* interface, 
                              IPCThreadState* threadState) const

{

    if (auto* kernelFields = maybeKernelFields()) {

#ifdef BINDER_WITH_KERNEL_IPC

        // StrictModePolicy.

        int32_t strictPolicy = readInt32();

        if (threadState == nullptr) {
@@ -891,6 +941,11 @@ bool Parcel::enforceInterface(const char16_t* interface, 
                  header);

            return false;

        }

#else  // BINDER_WITH_KERNEL_IPC

        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

        (void)threadState;

        return false;

#endif // BINDER_WITH_KERNEL_IPC

    }



    // Interface descriptor.
@@ -1401,6 +1456,7 @@ status_t Parcel::writeFileDescriptor(int fd, bool takeOwnership) { 
        }

    }



#ifdef BINDER_WITH_KERNEL_IPC

    flat_binder_object obj;

    obj.hdr.type = BINDER_TYPE_FD;

    obj.flags = 0x7f | FLAT_BINDER_FLAG_ACCEPTS_FDS;
@@ -1408,6 +1464,12 @@ status_t Parcel::writeFileDescriptor(int fd, bool takeOwnership) { 
    obj.handle = fd;

    obj.cookie = takeOwnership ? 1 : 0;

    return writeObject(obj, true);

#else  // BINDER_WITH_KERNEL_IPC

    LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

    (void)fd;

    (void)takeOwnership;

    return INVALID_OPERATION;

#endif // BINDER_WITH_KERNEL_IPC

}



status_t Parcel::writeDupFileDescriptor(int fd)
@@ -1561,6 +1623,7 @@ status_t Parcel::writeObject(const flat_binder_object& val, bool nullMetaData) 
    auto* kernelFields = maybeKernelFields();

    LOG_ALWAYS_FATAL_IF(kernelFields == nullptr, "Can't write flat_binder_object to RPC Parcel");



#ifdef BINDER_WITH_KERNEL_IPC

    const bool enoughData = (mDataPos+sizeof(val)) <= mDataCapacity;

    const bool enoughObjects = kernelFields->mObjectsSize < kernelFields->mObjectsCapacity;

    if (enoughData && enoughObjects) {
@@ -1603,6 +1666,12 @@ restart_write: 
    }



    goto restart_write;

#else  // BINDER_WITH_KERNEL_IPC

    LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

    (void)val;

    (void)nullMetaData;

    return INVALID_OPERATION;

#endif // BINDER_WITH_KERNEL_IPC

}



status_t Parcel::writeNoException()
@@ -1620,6 +1689,7 @@ status_t Parcel::validateReadData(size_t upperBound) const 
        return OK;

    }



#ifdef BINDER_WITH_KERNEL_IPC

    // Don't allow non-object reads on object data

    if (kernelFields->mObjectsSorted || kernelFields->mObjectsSize <= 1) {

    data_sorted:
@@ -1672,6 +1742,10 @@ data_unsorted: 
    kernelFields->mNextObjectHint = 0;

    kernelFields->mObjectsSorted = true;

    goto data_sorted;

#else  // BINDER_WITH_KERNEL_IPC

    (void)upperBound;

    return NO_ERROR;

#endif // BINDER_WITH_KERNEL_IPC

}



status_t Parcel::read(void* outData, size_t len) const
@@ -2164,6 +2238,7 @@ int Parcel::readFileDescriptor() const { 
        return toRawFd(rpcFields->mFds->at(fdIndex));

    }



#ifdef BINDER_WITH_KERNEL_IPC

    const flat_binder_object* flat = readObject(true);



    if (flat && flat->hdr.type == BINDER_TYPE_FD) {
@@ -2171,6 +2246,10 @@ int Parcel::readFileDescriptor() const { 
    }



    return BAD_TYPE;

#else  // BINDER_WITH_KERNEL_IPC

    LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

    return INVALID_OPERATION;

#endif // BINDER_WITH_KERNEL_IPC

}



int Parcel::readParcelFileDescriptor() const {
@@ -2326,6 +2405,8 @@ status_t Parcel::read(FlattenableHelperInterface& val) const 


    return err;

}



#ifdef BINDER_WITH_KERNEL_IPC

const flat_binder_object* Parcel::readObject(bool nullMetaData) const

{

    const auto* kernelFields = maybeKernelFields();
@@ -2391,9 +2472,11 @@ const flat_binder_object* Parcel::readObject(bool nullMetaData) const 
    }

    return nullptr;

}

#endif // BINDER_WITH_KERNEL_IPC



void Parcel::closeFileDescriptors() {

    if (auto* kernelFields = maybeKernelFields()) {

#ifdef BINDER_WITH_KERNEL_IPC

        size_t i = kernelFields->mObjectsSize;

        if (i > 0) {

            // ALOGI("Closing file descriptors for %zu objects...", i);
@@ -2407,6 +2490,9 @@ void Parcel::closeFileDescriptors() { 
                close(flat->handle);

            }

        }

#else  // BINDER_WITH_KERNEL_IPC

        LOG_ALWAYS_FATAL("Binder kernel driver disabled at build time");

#endif // BINDER_WITH_KERNEL_IPC

    } else if (auto* rpcFields = maybeRpcFields()) {

        rpcFields->mFds.reset();

    }
@@ -2454,6 +2540,7 @@ void Parcel::ipcSetDataReference(const uint8_t* data, size_t dataSize, const bin 
    kernelFields->mObjectsSize = kernelFields->mObjectsCapacity = objectsCount;

    mOwner = relFunc;



#ifdef BINDER_WITH_KERNEL_IPC

    binder_size_t minOffset = 0;

    for (size_t i = 0; i < kernelFields->mObjectsSize; i++) {

        binder_size_t offset = kernelFields->mObjects[i];
@@ -2484,6 +2571,10 @@ void Parcel::ipcSetDataReference(const uint8_t* data, size_t dataSize, const bin 
        minOffset = offset + sizeof(flat_binder_object);

    }

    scanForFds();

#else  // BINDER_WITH_KERNEL_IPC

    LOG_ALWAYS_FATAL_IF(objectsCount != 0,

                        "Non-zero objects count passed to Parcel with kernel driver disabled");

#endif // BINDER_WITH_KERNEL_IPC

}



status_t Parcel::rpcSetDataReference(
@@ -2534,6 +2625,7 @@ void Parcel::print(TextOutput& to, uint32_t /*flags*/) const 
    } else if (dataSize() > 0) {

        const uint8_t* DATA = data();

        to << indent << HexDump(DATA, dataSize()) << dedent;

#ifdef BINDER_WITH_KERNEL_IPC

        if (const auto* kernelFields = maybeKernelFields()) {

            const binder_size_t* OBJS = kernelFields->mObjects;

            const size_t N = objectsCount();
@@ -2545,6 +2637,7 @@ void Parcel::print(TextOutput& to, uint32_t /*flags*/) const 
                   << TypeCode(flat->hdr.type & 0x7f7f7f00) << " = " << flat->binder;

            }

        }

#endif // BINDER_WITH_KERNEL_IPC

    } else {

        to << "NULL";

    }
@@ -2559,6 +2652,7 @@ void Parcel::releaseObjects() 
        return;

    }



#ifdef BINDER_WITH_KERNEL_IPC

    size_t i = kernelFields->mObjectsSize;

    if (i == 0) {

        return;
@@ -2571,6 +2665,7 @@ void Parcel::releaseObjects() 
        const flat_binder_object* flat = reinterpret_cast<flat_binder_object*>(data + objects[i]);

        release_object(proc, *flat, this);

    }

#endif // BINDER_WITH_KERNEL_IPC

}



void Parcel::acquireObjects()
@@ -2580,6 +2675,7 @@ void Parcel::acquireObjects() 
        return;

    }



#ifdef BINDER_WITH_KERNEL_IPC

    size_t i = kernelFields->mObjectsSize;

    if (i == 0) {

        return;
@@ -2592,6 +2688,7 @@ void Parcel::acquireObjects() 
        const flat_binder_object* flat = reinterpret_cast<flat_binder_object*>(data + objects[i]);

        acquire_object(proc, *flat, this);

    }

#endif // BINDER_WITH_KERNEL_IPC

}



void Parcel::freeData()
@@ -2813,6 +2910,7 @@ status_t Parcel::continueWrite(size_t desired) 


    } else if (mData) {

        if (kernelFields && objectsSize < kernelFields->mObjectsSize) {

#ifdef BINDER_WITH_KERNEL_IPC

            // Need to release refs on any objects we are dropping.

            const sp<ProcessState> proc(ProcessState::self());

            for (size_t i = objectsSize; i < kernelFields->mObjectsSize; i++) {
@@ -2841,6 +2939,9 @@ status_t Parcel::continueWrite(size_t desired) 
            kernelFields->mObjectsSize = objectsSize;

            kernelFields->mNextObjectHint = 0;

            kernelFields->mObjectsSorted = false;

#else  // BINDER_WITH_KERNEL_IPC

            LOG_ALWAYS_FATAL("Non-zero numObjects for RPC Parcel");

#endif // BINDER_WITH_KERNEL_IPC

        }

        if (rpcFields) {

            if (status_t status = truncateRpcObjects(objectsSize); status != OK) {
@@ -2958,6 +3059,7 @@ void Parcel::scanForFds() const { 
    kernelFields->mFdsKnown = true;

}



#ifdef BINDER_WITH_KERNEL_IPC

size_t Parcel::getBlobAshmemSize() const

{

    // This used to return the size of all blobs that were written to ashmem, now we're returning
@@ -2990,6 +3092,7 @@ size_t Parcel::getOpenAshmemSize() const 
    }

    return openAshmemSize;

}

#endif // BINDER_WITH_KERNEL_IPC



// --- Parcel::Blob ---