tty: vt, remove reduntant check (182846a0) · Commits · 戴 / test

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>

drivers/tty/vt/vt.c

+0 −4

Original line number	Diff line number	Diff line
		@@ -768,10 +768,6 @@ int vc_allocate(unsigned int currcons) /* return 0 on success */
		struct vc_data *vc;
		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 */
		/* the alloc is done in two steps, to optimize the common situation
		of a 25x80 console (structsize=216, screenbuf_size=4000) */

include/uapi/linux/vt.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -8,7 +8,6 @@
		*/
		#define MIN_NR_CONSOLES 1 /* must be at least 1 */
		#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
		consoles 16 and higher (since it returns a short) */

Admin message