diff options
| author | Thomas Gleixner <tglx@linutronix.de> | 2017-08-15 13:03:47 +0200 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2017-08-15 13:03:47 +0200 |
| commit | 84393817db09bb436e934f8f8cc981cbca9ea4dc (patch) | |
| tree | 90759da335f746a81f1019271bfb75370dc38314 /arch/x86/mm/mmap.c | |
| parent | b45e4c45b13275a6b4a3f83ae8301a1963fbe5d0 (diff) | |
x86/mtrr: Prevent CPU hotplug lock recursion
Larry reported a CPU hotplug lock recursion in the MTRR code.
============================================
WARNING: possible recursive locking detected
systemd-udevd/153 is trying to acquire lock:
(cpu_hotplug_lock.rw_sem){.+.+.+}, at: [<c030fc26>] stop_machine+0x16/0x30
but task is already holding lock:
(cpu_hotplug_lock.rw_sem){.+.+.+}, at: [<c0234353>] mtrr_add_page+0x83/0x470
....
cpus_read_lock+0x48/0x90
stop_machine+0x16/0x30
mtrr_add_page+0x18b/0x470
mtrr_add+0x3e/0x70
mtrr_add_page() holds the hotplug rwsem already and calls stop_machine()
which acquires it again.
Call stop_machine_cpuslocked() instead.
Reported-and-tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1708140920250.1865@nanos
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Borislav Petkov <bp@suse.de>
Diffstat (limited to 'arch/x86/mm/mmap.c')
0 files changed, 0 insertions, 0 deletions