[Devel] [PATCH RHEL7 COMMIT] ve/tty: Use ve_capable in vhangup syscall

[Konstantin Khorenko]

The commit is pushed to "branch-rh7-3.10.0-229.7.2.vz7.8.x-ovz" and will appear at https://src.openvz.org/scm/ovz/vzkernel.git
after rh7-3.10.0-229.7.2.vz7.8.4
------>
commit 19dfba5f529f807de085534b8c7ff048007bf514
Author: Cyrill Gorcunov <gorcunov at virtuozzo.com>
Date:   Thu Oct 8 12:52:13 2015 +0400

    ve/tty: Use ve_capable in vhangup syscall
    
    In centos6 template uses mingetty as a login utility which
    calls for vhangup() syscall on startup. And both vanilla
    kernel and pcs7 now uses general capable() helper which is
    referred to init_user_ns regardless of which caps we setup
    for VE itself (the libvzctl sets up CAP_SYS_TTY_CONFIG
    properly for ve it simply is not taken into account here)
    so the syscall exits with -EPERM causing mingetty to respawn
    again and again.
    
    Thus use ve_capable helper instead.
    
    (FWIW in pcs6 we don't have such problem because capable()
    helper refers to current_cred directly).
    
    https://jira.sw.ru/browse/PSBM-40053
    
    Signed-off-by: Cyrill Gorcunov <gorcunov at virtuozzo.com>
    
    CC: Vladimir Davydov <vdavydov at virtuozzo.com>
    CC: Konstantin Khorenko <khorenko at virtuozzo.com>
    CC: Igor Sukhih <igor at parallels.com>
---
 fs/open.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/open.c b/fs/open.c
index ffb50fa..b61e3db 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -1115,7 +1115,7 @@ EXPORT_SYMBOL(sys_close);
  */
 SYSCALL_DEFINE0(vhangup)
 {
-	if (capable(CAP_SYS_TTY_CONFIG)) {
+	if (ve_capable(CAP_SYS_TTY_CONFIG)) {
 		tty_vhangup_self();
 		return 0;
 	}