Merge "libcutils: route to ashmemd"

 */

#define LOG_TAG "ashmem"

#ifndef __ANDROID_VNDK__

#include <dlfcn.h>

#endif

#include <errno.h>

#include <fcntl.h>

#include <linux/ashmem.h>

 */

static pthread_mutex_t __ashmem_lock = PTHREAD_MUTEX_INITIALIZER;

/*

 * We use ashmemd to enforce that apps don't open /dev/ashmem directly. Vendor

 * code can't access system aidl services per Treble requirements. So we limit

 * ashmemd access to the system variant of libcutils.

 */

#ifndef __ANDROID_VNDK__

using openFdType = int (*)();

openFdType initOpenAshmemFd() {

    openFdType openFd = nullptr;

    void* handle = dlopen("libashmemd_client.so", RTLD_NOW);

    if (!handle) {

        ALOGE("Failed to dlopen() libashmemd_client.so: %s", dlerror());

        return openFd;

    }

    openFd = reinterpret_cast<openFdType>(dlsym(handle, "openAshmemdFd"));

    if (!openFd) {

        ALOGE("Failed to dlsym() openAshmemdFd() function: %s", dlerror());

    }

    return openFd;

}

#endif

/* logistics of getting file descriptor for ashmem */

static int __ashmem_open_locked()

{

    int ret;

    struct stat st;

    int fd = TEMP_FAILURE_RETRY(open(ASHMEM_DEVICE, O_RDWR | O_CLOEXEC));

    int fd = -1;

#ifndef __ANDROID_VNDK__

    static auto openFd = initOpenAshmemFd();

    if (openFd) {

        fd = openFd();

    }

#endif

    if (fd < 0) {

        fd = TEMP_FAILURE_RETRY(open(ASHMEM_DEVICE, O_RDWR | O_CLOEXEC));

    }

    if (fd < 0) {

        return fd;

    }