aboutsummaryrefslogtreecommitdiff
path: root/arch
diff options
context:
space:
mode:
authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2013-04-16 15:18:00 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-05-07 20:33:06 -0700
commit3672f12220a0994d9e37d6e2bb93ac7ec1669d60 (patch)
tree1065b8818e73cb6f2641608eecf9d33be2ff8d59 /arch
parent5e5d3ee63ece3bcc2141dcd08306ecdf7ec30dcc (diff)
downloadvexpress-lsk-3672f12220a0994d9e37d6e2bb93ac7ec1669d60.tar.gz
xen/time: Fix kasprintf splat when allocating timer%d IRQ line.
commit 7918c92ae9638eb8a6ec18e2b4a0de84557cccc8 upstream. 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. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/xen/enlighten.c5
-rw-r--r--arch/x86/xen/time.c6
2 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index c8e1c7b95c3..2363127e94e 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -1589,8 +1589,11 @@ 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;
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 0296a952250..054cc01bb84 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -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();
}