diff options
Diffstat (limited to 'drivers/tty/tty_io.c')
| -rw-r--r-- | drivers/tty/tty_io.c | 50 |
1 files changed, 20 insertions, 30 deletions
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c index 27d8e3a1aace..8a94e5a43c6d 100644 --- a/drivers/tty/tty_io.c +++ b/drivers/tty/tty_io.c @@ -270,7 +270,7 @@ static int tty_paranoia_check(struct tty_struct *tty, struct inode *inode, } /* Caller must hold tty_lock */ -static int check_tty_count(struct tty_struct *tty, const char *routine) +static void check_tty_count(struct tty_struct *tty, const char *routine) { #ifdef CHECK_TTY_COUNT struct list_head *p; @@ -290,10 +290,8 @@ static int check_tty_count(struct tty_struct *tty, const char *routine) if (tty->count != (count + kopen_count)) { tty_warn(tty, "%s: tty->count(%d) != (#fd's(%d) + #kopen's(%d))\n", routine, tty->count, count, kopen_count); - return (count + kopen_count); } #endif - return 0; } /** @@ -845,19 +843,18 @@ static void tty_update_time(struct tty_struct *tty, bool mtime) * data or clears the cookie. The cookie may be something that the * ldisc maintains state for and needs to free. */ -static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, - struct file *file, struct iov_iter *to) +static ssize_t iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, + struct file *file, struct iov_iter *to) { - int retval = 0; void *cookie = NULL; unsigned long offset = 0; char kernel_buf[64]; - size_t count = iov_iter_count(to); + ssize_t retval = 0; + size_t copied, count = iov_iter_count(to); do { - int size, copied; + ssize_t size = min(count, sizeof(kernel_buf)); - size = count > sizeof(kernel_buf) ? sizeof(kernel_buf) : count; size = ld->ops->read(tty, file, kernel_buf, size, &cookie, offset); if (!size) break; @@ -914,11 +911,11 @@ static int iterate_tty_read(struct tty_ldisc *ld, struct tty_struct *tty, */ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) { - int i; struct file *file = iocb->ki_filp; struct inode *inode = file_inode(file); struct tty_struct *tty = file_tty(file); struct tty_ldisc *ld; + ssize_t ret; if (tty_paranoia_check(tty, inode, "tty_read")) return -EIO; @@ -931,15 +928,15 @@ static ssize_t tty_read(struct kiocb *iocb, struct iov_iter *to) ld = tty_ldisc_ref_wait(tty); if (!ld) return hung_up_tty_read(iocb, to); - i = -EIO; + ret = -EIO; if (ld->ops->read) - i = iterate_tty_read(ld, tty, file, to); + ret = iterate_tty_read(ld, tty, file, to); tty_ldisc_deref(ld); - if (i > 0) + if (ret > 0) tty_update_time(tty, false); - return i; + return ret; } void tty_write_unlock(struct tty_struct *tty) @@ -948,7 +945,7 @@ void tty_write_unlock(struct tty_struct *tty) wake_up_interruptible_poll(&tty->write_wait, EPOLLOUT); } -int tty_write_lock(struct tty_struct *tty, int ndelay) +int tty_write_lock(struct tty_struct *tty, bool ndelay) { if (!mutex_trylock(&tty->atomic_write_lock)) { if (ndelay) @@ -963,15 +960,11 @@ int tty_write_lock(struct tty_struct *tty, int ndelay) * Split writes up in sane blocksizes to avoid * denial-of-service type attacks */ -static inline ssize_t do_tty_write( - ssize_t (*write)(struct tty_struct *, struct file *, const unsigned char *, size_t), - struct tty_struct *tty, - struct file *file, - struct iov_iter *from) +static ssize_t iterate_tty_write(struct tty_ldisc *ld, struct tty_struct *tty, + struct file *file, struct iov_iter *from) { - size_t count = iov_iter_count(from); + size_t chunk, count = iov_iter_count(from); ssize_t ret, written = 0; - unsigned int chunk; ret = tty_write_lock(tty, file->f_flags & O_NDELAY); if (ret < 0) @@ -1015,16 +1008,13 @@ static inline ssize_t do_tty_write( /* Do the write .. */ for (;;) { - size_t size = count; - - if (size > chunk) - size = chunk; + size_t size = min(chunk, count); ret = -EFAULT; if (copy_from_iter(tty->write_buf, size, from) != size) break; - ret = write(tty, file, tty->write_buf, size); + ret = ld->ops->write(tty, file, tty->write_buf, size); if (ret <= 0) break; @@ -1095,7 +1085,7 @@ static ssize_t file_tty_write(struct file *file, struct kiocb *iocb, struct iov_ if (!ld->ops->write) ret = -EIO; else - ret = do_tty_write(ld->ops->write, tty, file, from); + ret = iterate_tty_write(ld, tty, file, from); tty_ldisc_deref(ld); return ret; } @@ -1162,7 +1152,7 @@ int tty_send_xchar(struct tty_struct *tty, char ch) return 0; } - if (tty_write_lock(tty, 0) < 0) + if (tty_write_lock(tty, false) < 0) return -ERESTARTSYS; down_read(&tty->termios_rwsem); @@ -2488,7 +2478,7 @@ static int send_break(struct tty_struct *tty, unsigned int duration) retval = tty->ops->break_ctl(tty, duration); else { /* Do the work ourselves */ - if (tty_write_lock(tty, 0) < 0) + if (tty_write_lock(tty, false) < 0) return -EINTR; retval = tty->ops->break_ctl(tty, -1); if (retval) |