[PATCH 3.16 211/366] tty: vt, remove reduntant check

[Ben Hutchings]

3.16.61-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Jiri Slaby <jslaby@xxxxxxx>

commit 182846a00f489849c55d113954f0c4a8a286ca39 upstream.

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@xxxxxxx>
Reported-by: Fugang Duan <fugang.duan@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/tty/vt/vt.c     | 4 ----
 include/uapi/linux/vt.h | 1 -
 2 files changed, 5 deletions(-)

--- a/drivers/tty/vt/vt.c
+++ b/drivers/tty/vt/vt.c
@@ -760,10 +760,6 @@ int vc_allocate(unsigned int currcons)	/
 	    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) */
--- a/include/uapi/linux/vt.h
+++ b/include/uapi/linux/vt.h
@@ -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) */