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Thomas Gleixner 84393817db 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>

2017-08-15 13:03:47 +02:00

amd.c

x86, mtrr: Constify struct mtrr_ops

2010-02-01 11:20:43 -08:00

centaur.c

x86/cpu: Convert printk(KERN_<LEVEL> ...) to pr_<level>(...)

2016-02-03 10:30:03 +01:00

cleanup.c

x86/boot/e820: Prefix the E820_* type names with "E820_TYPE_"

2017-01-28 22:55:22 +01:00

cyrix.c

x86/cpufeature: Remove cpu_has_pge