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tty: vt, remove reduntant check

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MAX_NR_CONSOLES and MAX_NR_USER_CONSOLES are both 63 since they were
introduced in 1.1.54. And since vc_allocate does:

if (currcons >= MAX_NR_CONSOLES)
	return -ENXIO;

if (!vc_cons[currcons].d) {
	if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
		return -EPERM;
}

the second check is pointless. Remove both the check and the macro
MAX_NR_USER_CONSOLES.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Reported-by: Fugang Duan <fugang.duan@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jiri Slaby 2016-03-31 10:08:14 +02:00 committed by Greg Kroah-Hartman
parent b8995f527a
commit 182846a00f
2 changed files with 0 additions and 5 deletions
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4
drivers/tty/vt/vt.c
View file

@ -768,10 +768,6 @@ int vc_allocate(unsigned int currcons) /* return 0 on success */
struct vc_data *vc; struct vc_data *vc;
struct vt_notifier_param param; struct vt_notifier_param param;
/* prevent users from taking too much memory */
if (currcons >= MAX_NR_USER_CONSOLES && !capable(CAP_SYS_RESOURCE))
return -EPERM;
/* due to the granularity of kmalloc, we waste some memory here */ /* due to the granularity of kmalloc, we waste some memory here */
/* the alloc is done in two steps, to optimize the common situation /* the alloc is done in two steps, to optimize the common situation
of a 25x80 console (structsize=216, screenbuf_size=4000) */ of a 25x80 console (structsize=216, screenbuf_size=4000) */

1
include/uapi/linux/vt.h
View file

@ -8,7 +8,6 @@
*/ */
#define MIN_NR_CONSOLES 1 /* must be at least 1 */ #define MIN_NR_CONSOLES 1 /* must be at least 1 */
#define MAX_NR_CONSOLES 63 /* serial lines start at 64 */ #define MAX_NR_CONSOLES 63 /* serial lines start at 64 */
#define MAX_NR_USER_CONSOLES 63 /* must be root to allocate above this */
/* Note: the ioctl VT_GETSTATE does not work for /* Note: the ioctl VT_GETSTATE does not work for
consoles 16 and higher (since it returns a short) */ consoles 16 and higher (since it returns a short) */