Commit 484923ad authored by Jiri Slaby's avatar Jiri Slaby Committed by Greg Kroah-Hartman
Browse files

tty/vt: consolemap: walk the buffer only once in con_set_trans_old() 



Fetch the user data one by one (by get_user()) and fill in the local
buffer simultaneously. I.e. we no longer require to walk two buffers and
save thus 256 B from stack (whole ubuf).

Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
Link: https://lore.kernel.org/r/20220607104946.18710-36-jslaby@suse.cz


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent fc440658

drivers/tty/vt/consolemap.c

+7 −7
Original line number Diff line number Diff line
@@ -343,15 +343,15 @@ static void update_user_maps(void) 
 */

int con_set_trans_old(unsigned char __user * arg)

{

	int i;

	unsigned short inbuf[E_TABSZ];

	unsigned char ubuf[E_TABSZ];

	unsigned int i;

	unsigned char ch;



	if (copy_from_user(ubuf, arg, E_TABSZ))

	for (i = 0; i < ARRAY_SIZE(inbuf); i++) {

		if (get_user(ch, &arg[i]))

			return -EFAULT;



	for (i = 0; i < E_TABSZ ; i++)

		inbuf[i] = UNI_DIRECT_BASE | ubuf[i];

		inbuf[i] = UNI_DIRECT_BASE | ch;

	}



	console_lock();

	memcpy(translations[USER_MAP], inbuf, sizeof(inbuf));