Function memfd_create_region_post_q

app/src/main/cpp/utils/shared_memory.cpp:41–55

#define ASHMEM_NAME_LEN 256

static int memfd_create_region_post_q(const char *name, size_t size) {
    // This code needs to build on old API levels, so we can't use the libc
    // wrapper.
    int fd = (int) syscall(__NR_memfd_create, name, MFD_CLOEXEC | MFD_ALLOW_SEALING);
    if (fd == -1) {
        return -errno;
    }
    if (ftruncate(fd, size) == -1) {
        int orig = errno;
        close(fd);
        errno = orig;
        return -orig;
    }
    return fd;
}

static bool testMemfdSupport() {
    int fd = (int) syscall(__NR_memfd_create, "test_support_memfd", MFD_CLOEXEC | MFD_ALLOW_SEALING);