linux_dsm_epyc7002/drivers/video/console/dummycon.c
Nicolas Pitre 724ba8b30b console/dummy: leave .con_font_get set to NULL
When this method is set, the caller expects struct console_font fields
to be properly initialized when it returns. Leave it unset otherwise
nonsensical (leaked kernel stack) values are returned to user space.

Signed-off-by: Nicolas Pitre <nico@linaro.org>
Cc: stable@vger.kernel.org
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
2018-01-15 17:04:22 +01:00

74 lines
1.6 KiB
C

/*
* linux/drivers/video/dummycon.c -- A dummy console driver
*
* To be used if there's no other console driver (e.g. for plain VGA text)
* available, usually until fbcon takes console over.
*/
#include <linux/types.h>
#include <linux/kdev_t.h>
#include <linux/console.h>
#include <linux/vt_kern.h>
#include <linux/screen_info.h>
#include <linux/init.h>
#include <linux/module.h>
/*
* Dummy console driver
*/
#if defined(__arm__)
#define DUMMY_COLUMNS screen_info.orig_video_cols
#define DUMMY_ROWS screen_info.orig_video_lines
#else
/* set by Kconfig. Use 80x25 for 640x480 and 160x64 for 1280x1024 */
#define DUMMY_COLUMNS CONFIG_DUMMY_CONSOLE_COLUMNS
#define DUMMY_ROWS CONFIG_DUMMY_CONSOLE_ROWS
#endif
static const char *dummycon_startup(void)
{
return "dummy device";
}
static void dummycon_init(struct vc_data *vc, int init)
{
vc->vc_can_do_color = 1;
if (init) {
vc->vc_cols = DUMMY_COLUMNS;
vc->vc_rows = DUMMY_ROWS;
} else
vc_resize(vc, DUMMY_COLUMNS, DUMMY_ROWS);
}
static int dummycon_dummy(void)
{
return 0;
}
#define DUMMY (void *)dummycon_dummy
/*
* The console `switch' structure for the dummy console
*
* Most of the operations are dummies.
*/
const struct consw dummy_con = {
.owner = THIS_MODULE,
.con_startup = dummycon_startup,
.con_init = dummycon_init,
.con_deinit = DUMMY,
.con_clear = DUMMY,
.con_putc = DUMMY,
.con_putcs = DUMMY,
.con_cursor = DUMMY,
.con_scroll = DUMMY,
.con_switch = DUMMY,
.con_blank = DUMMY,
.con_font_set = DUMMY,
.con_font_default = DUMMY,
.con_font_copy = DUMMY,
};
EXPORT_SYMBOL_GPL(dummy_con);