]> git.proxmox.com Git - mirror_ubuntu-kernels.git/commit
x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled
authorPrarit Bhargava <prarit@redhat.com>
Mon, 10 Jun 2019 17:15:44 +0000 (13:15 -0400)
committerThomas Gleixner <tglx@linutronix.de>
Wed, 12 Jun 2019 08:31:50 +0000 (10:31 +0200)
commitc7563e62a6d720aa3b068e26ddffab5f0df29263
tree79924a1f6a54b6d5f8038413b6392048065244f3
parent87d3aa28f345bea77c396855fa5d5fec4c24461f
x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled

Booting with kernel parameter "rdt=cmt,mbmtotal,memlocal,l3cat,mba" and
executing "mount -t resctrl resctrl -o mba_MBps /sys/fs/resctrl" results in
a NULL pointer dereference on systems which do not have local MBM support
enabled..

BUG: kernel NULL pointer dereference, address: 0000000000000020
PGD 0 P4D 0
Oops: 0000 [#1] SMP PTI
CPU: 0 PID: 722 Comm: kworker/0:3 Not tainted 5.2.0-0.rc3.git0.1.el7_UNSUPPORTED.x86_64 #2
Workqueue: events mbm_handle_overflow
RIP: 0010:mbm_handle_overflow+0x150/0x2b0

Only enter the bandwith update loop if the system has local MBM enabled.

Fixes: de73f38f7680 ("x86/intel_rdt/mba_sc: Feedback loop to dynamically update mem bandwidth")
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Reinette Chatre <reinette.chatre@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190610171544.13474-1-prarit@redhat.com
arch/x86/kernel/cpu/resctrl/monitor.c