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authorHeiko Carstens <heiko.carstens@de.ibm.com>2009-01-07 16:19:46 +0100
committerLinus Torvalds <torvalds@linux-foundation.org>2009-01-07 11:36:14 -0800
commita0e280e0f33f6c859a235fb69a875ed8f3420388 (patch)
treec41b0ad22c4195bef2bfdd36437e20d232b9586b /kernel/cpu.c
parent30aafdba6f78619274a977d67283a681bedbcbbd (diff)
downloadlinux-2.6.34-ux500-a0e280e0f33f6c859a235fb69a875ed8f3420388.tar.gz
stop_machine/cpu hotplug: fix disable_nonboot_cpus
disable_nonboot_cpus calls _cpu_down. But _cpu_down requires that the caller already created the stop_machine workqueue (like cpu_down does). Otherwise a call to stop_machine will lead to accesses to random memory regions. When introducing this new interface (9ea09af3bd3090e8349ca2899ca2011bd94cda85 "stop_machine: introduce stop_machine_create/destroy") I missed the second call site of _cpu_down. So add the missing stop_machine_create/destroy calls to disable_nonboot_cpus as well. Fixes suspend-to-ram/disk and also this bug: [ 286.547348] BUG: unable to handle kernel paging request at 6b6b6b6b [ 286.548940] IP: [<c0150ca4>] __stop_machine+0x88/0xe3 [ 286.550598] Oops: 0002 [#1] SMP [ 286.560580] Pid: 3273, comm: halt Not tainted (2.6.28-06127-g238c6d5 [ 286.560580] EIP: is at __stop_machine+0x88/0xe3 [ 286.560580] Process halt (pid: 3273, ti=f1a28000 task=f4530f30 [ 286.560580] Call Trace: [ 286.560580] [<c03d04e4>] ? _cpu_down+0x10f/0x234 [ 286.560580] [<c012a57e>] ? disable_nonboot_cpus+0x58/0xdc [ 286.560580] [<c01360c0>] ? kernel_poweroff+0x22/0x39 [ 286.560580] [<c0136301>] ? sys_reboot+0xde/0x14c [ 286.560580] [<c01331b2>] ? complete_signal+0x179/0x191 [ 286.560580] [<c0133396>] ? send_signal+0x1cc/0x1e1 [ 286.560580] [<c03de418>] ? _spin_unlock_irqrestore+0x2d/0x3c [ 286.560580] [<c0133b65>] ? group_send_signal_info+0x58/0x61 [ 286.560580] [<c0133b9e>] ? kill_pid_info+0x30/0x3a [ 286.560580] [<c0133d49>] ? sys_kill+0x75/0x13a [ 286.560580] [<c01a06cb>] ? mntput_no_expire+ox1f/0x101 [ 286.560580] [<c019b3b3>] ? dput+0x1e/0x105 [ 286.560580] [<c018ef87>] ? __fput+0x150/0x158 [ 286.560580] [<c0157abf>] ? audit_syscall_entry+0x137/0x159 [ 286.560580] [<c010329f>] ? sysenter_do_call+0x12/0x34 Reported-and-tested-by: "Justin P. Mattock" <justinmattock@gmail.com> Reviewed-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/cpu.c')
-rw-r--r--kernel/cpu.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 30e74dd6d01..79e40f00dcb 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -379,8 +379,11 @@ static cpumask_var_t frozen_cpus;
int disable_nonboot_cpus(void)
{
- int cpu, first_cpu, error = 0;
+ int cpu, first_cpu, error;
+ error = stop_machine_create();
+ if (error)
+ return error;
cpu_maps_update_begin();
first_cpu = cpumask_first(cpu_online_mask);
/* We take down all of the non-boot CPUs in one shot to avoid races
@@ -409,6 +412,7 @@ int disable_nonboot_cpus(void)
printk(KERN_ERR "Non-boot CPUs are not disabled\n");
}
cpu_maps_update_done();
+ stop_machine_destroy();
return error;
}