diff options
Diffstat (limited to 'drivers/char/ppdev.c')
| -rw-r--r-- | drivers/char/ppdev.c | 26 |
1 files changed, 16 insertions, 10 deletions
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c index 07877c1a7..9b85db1d6 100644 --- a/drivers/char/ppdev.c +++ b/drivers/char/ppdev.c @@ -39,7 +39,13 @@ * read/write read or write in current IEEE 1284 protocol * select wait for interrupt (in readfds) * + * Changes: * Added SETTIME/GETTIME ioctl, Fred Barnes 1999. + * + * Arnaldo Carvalho de Melo <acme@conectiva.com.br> 2000/08/25 + * - On error, copy_from_user and copy_to_user do not return -EFAULT, + * They return the positive number of bytes *not* copied due to address + * space errors. */ #include <linux/module.h> @@ -179,7 +185,7 @@ static ssize_t pp_write (struct file * file, const char * buf, size_t count, wrote = parport_write (pp->pdev->port, kbuffer, n); - if (wrote < 0) { + if (wrote <= 0) { if (!bytes_written) bytes_written = wrote; break; @@ -369,19 +375,19 @@ static int pp_ioctl(struct inode *inode, struct file *file, case PPRSTATUS: reg = parport_read_status (port); - return copy_to_user ((unsigned char *) arg, ®, - sizeof (reg)); - + if (copy_to_user ((unsigned char *) arg, ®, sizeof (reg))) + return -EFAULT; + return 0; case PPRDATA: reg = parport_read_data (port); - return copy_to_user ((unsigned char *) arg, ®, - sizeof (reg)); - + if (copy_to_user ((unsigned char *) arg, ®, sizeof (reg))) + return -EFAULT; + return 0; case PPRCONTROL: reg = parport_read_control (port); - return copy_to_user ((unsigned char *) arg, ®, - sizeof (reg)); - + if (copy_to_user ((unsigned char *) arg, ®, sizeof (reg))) + return -EFAULT; + return 0; case PPYIELD: parport_yield_blocking (pp->pdev); return 0; |