diff options
Diffstat (limited to 'drivers/char/hvc_vio.c')
| -rw-r--r-- | drivers/char/hvc_vio.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/char/hvc_vio.c b/drivers/char/hvc_vio.c index f5212eb2b41..9add81ceb44 100644 --- a/drivers/char/hvc_vio.c +++ b/drivers/char/hvc_vio.c @@ -31,10 +31,13 @@ #include <linux/types.h> #include <linux/init.h> + #include <asm/hvconsole.h> #include <asm/vio.h> #include <asm/prom.h> +#include "hvc_console.h" + char hvc_driver_name[] = "hvc_console"; static struct vio_device_id hvc_driver_table[] __devinitdata = { @@ -48,6 +51,14 @@ static int filtered_get_chars(uint32_t vtermno, char *buf, int count) unsigned long got; int i; + /* + * Vio firmware will read up to SIZE_VIO_GET_CHARS at its own discretion + * so we play safe and avoid the situation where got > count which could + * overload the flip buffer. + */ + if (count < SIZE_VIO_GET_CHARS) + return -EAGAIN; + got = hvc_get_chars(vtermno, buf, count); /* |