mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
xen/time: Fix kasprintf splat when allocating timer%d IRQ line.
When we online the CPU, we get this splat: smpboot: Booting Node 0 Processor 1 APIC 0x2 installing Xen timer for CPU 1 BUG: sleeping function called from invalid context at /home/konrad/ssd/konrad/linux/mm/slab.c:3179 in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/1 Pid: 0, comm: swapper/1 Not tainted 3.9.0-rc6upstream-00001-g3884fad #1 Call Trace: [<ffffffff810c1fea>] __might_sleep+0xda/0x100 [<ffffffff81194617>] __kmalloc_track_caller+0x1e7/0x2c0 [<ffffffff81303758>] ? kasprintf+0x38/0x40 [<ffffffff813036eb>] kvasprintf+0x5b/0x90 [<ffffffff81303758>] kasprintf+0x38/0x40 [<ffffffff81044510>] xen_setup_timer+0x30/0xb0 [<ffffffff810445af>] xen_hvm_setup_cpu_clockevents+0x1f/0x30 [<ffffffff81666d0a>] start_secondary+0x19c/0x1a8 The solution to that is use kasprintf in the CPU hotplug path that 'online's the CPU. That is, do it in in xen_hvm_cpu_notify, and remove the call to in xen_hvm_setup_cpu_clockevents. Unfortunatly the later is not a good idea as the bootup path does not use xen_hvm_cpu_notify so we would end up never allocating timer%d interrupt lines when booting. As such add the check for atomic() to continue. CC: stable@vger.kernel.org Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
parent
66ff0fe9e7
commit
7918c92ae9
2 changed files with 9 additions and 2 deletions
|
@ -1641,8 +1641,11 @@ static int __cpuinit xen_hvm_cpu_notify(struct notifier_block *self,
|
|||
switch (action) {
|
||||
case CPU_UP_PREPARE:
|
||||
xen_vcpu_setup(cpu);
|
||||
if (xen_have_vector_callback)
|
||||
if (xen_have_vector_callback) {
|
||||
xen_init_lock_cpu(cpu);
|
||||
if (xen_feature(XENFEAT_hvm_safe_pvclock))
|
||||
xen_setup_timer(cpu);
|
||||
}
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
|
|
|
@ -497,7 +497,11 @@ static void xen_hvm_setup_cpu_clockevents(void)
|
|||
{
|
||||
int cpu = smp_processor_id();
|
||||
xen_setup_runstate_info(cpu);
|
||||
xen_setup_timer(cpu);
|
||||
/*
|
||||
* xen_setup_timer(cpu) - snprintf is bad in atomic context. Hence
|
||||
* doing it xen_hvm_cpu_notify (which gets called by smp_init during
|
||||
* early bootup and also during CPU hotplug events).
|
||||
*/
|
||||
xen_setup_cpu_clockevents();
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue