diff options
| author | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-04-16 15:18:00 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-05-07 19:51:53 -0700 |
| commit | 0c6ad85215e151e96a0af63f7012d6642c23e3bd (patch) | |
| tree | 989df004ae26837655f4ffafab761ce3624aed79 | |
| parent | 403e8ff46d44eab2c5e83acb4b15cf21a8a05c3e (diff) | |
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>
| -rw-r--r-- | arch/x86/xen/enlighten.c | 5 | ||||
| -rw-r--r-- | arch/x86/xen/time.c | 6 |
2 files changed, 9 insertions, 2 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c index 194dbcd7e5da..29926785f07b 100644 --- a/arch/x86/xen/enlighten.c +++ b/arch/x86/xen/enlighten.c @@ -1515,8 +1515,11 @@ 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 0296a9522501..054cc01bb849 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(); } |