arch/um/os-Linux/tty.c

Source file repositories/reference/linux-study-clean/arch/um/os-Linux/tty.c

File Facts

System
Linux kernel
Corpus path
arch/um/os-Linux/tty.c
Extension
.c
Size
1043 bytes
Lines
61
Domain
Architecture Layer
Bucket
arch/um
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

struct grantpt_info {
	int fd;
	int res;
	int err;
};

static void grantpt_cb(void *arg)
{
	struct grantpt_info *info = arg;

	info->res = grantpt(info->fd);
	info->err = errno;
}

int get_pty(void)
{
	struct grantpt_info info;
	int fd, err;

	fd = open("/dev/ptmx", O_RDWR);
	if (fd < 0) {
		err = -errno;
		printk(UM_KERN_ERR "get_pty : Couldn't open /dev/ptmx - "
		       "err = %d\n", errno);
		return err;
	}

	info.fd = fd;
	initial_thread_cb(grantpt_cb, &info);

	if (info.res < 0) {
		err = -info.err;
		printk(UM_KERN_ERR "get_pty : Couldn't grant pty - "
		       "errno = %d\n", -info.err);
		goto out;
	}

	if (unlockpt(fd) < 0) {
		err = -errno;
		printk(UM_KERN_ERR "get_pty : Couldn't unlock pty - "
		       "errno = %d\n", errno);
		goto out;
	}
	return fd;
out:
	close(fd);
	return err;
}

Annotation

Implementation Notes