register_nmi_handler() can be called from PREEMPT_RT atomic context
(e.g. wakeup_cpu_via_init_nmi() or native_stop_other_cpus()), and thus
ordinary spinlocks cannot be used.
Signed-off-by: Scott Wood <[email protected]>
---
arch/x86/kernel/nmi.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 446c8aa09b9b..35aafc95e4b8 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -39,26 +39,26 @@
#include <trace/events/nmi.h>
struct nmi_desc {
- spinlock_t lock;
+ raw_spinlock_t lock;
struct list_head head;
};
static struct nmi_desc nmi_desc[NMI_MAX] =
{
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[0].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[0].lock),
.head = LIST_HEAD_INIT(nmi_desc[0].head),
},
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[1].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[1].lock),
.head = LIST_HEAD_INIT(nmi_desc[1].head),
},
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[2].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[2].lock),
.head = LIST_HEAD_INIT(nmi_desc[2].head),
},
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock),
.head = LIST_HEAD_INIT(nmi_desc[3].head),
},
@@ -163,7 +163,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
init_irq_work(&action->irq_work, nmi_max_handler);
- spin_lock_irqsave(&desc->lock, flags);
+ raw_spin_lock_irqsave(&desc->lock, flags);
/*
* Indicate if there are multiple registrations on the
@@ -181,7 +181,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
else
list_add_tail_rcu(&action->list, &desc->head);
- spin_unlock_irqrestore(&desc->lock, flags);
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(__register_nmi_handler);
@@ -192,7 +192,7 @@ void unregister_nmi_handler(unsigned int type, const char *name)
struct nmiaction *n;
unsigned long flags;
- spin_lock_irqsave(&desc->lock, flags);
+ raw_spin_lock_irqsave(&desc->lock, flags);
list_for_each_entry_rcu(n, &desc->head, list) {
/*
@@ -207,7 +207,7 @@ void unregister_nmi_handler(unsigned int type, const char *name)
}
}
- spin_unlock_irqrestore(&desc->lock, flags);
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
synchronize_rcu();
}
EXPORT_SYMBOL_GPL(unregister_nmi_handler);
--
1.8.3.1
On Mon, Jul 24, 2017 at 04:32:42PM -0500, Scott Wood wrote:
> register_nmi_handler() can be called from PREEMPT_RT atomic context
> (e.g. wakeup_cpu_via_init_nmi() or native_stop_other_cpus()), and thus
> ordinary spinlocks cannot be used.
Yeah, I guess we have a few awkward places where we register an nmi handler.
Acked-by: Don Zickus <[email protected]>
>
> Signed-off-by: Scott Wood <[email protected]>
> ---
> arch/x86/kernel/nmi.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
>
> diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
> index 446c8aa09b9b..35aafc95e4b8 100644
> --- a/arch/x86/kernel/nmi.c
> +++ b/arch/x86/kernel/nmi.c
> @@ -39,26 +39,26 @@
> #include <trace/events/nmi.h>
>
> struct nmi_desc {
> - spinlock_t lock;
> + raw_spinlock_t lock;
> struct list_head head;
> };
>
> static struct nmi_desc nmi_desc[NMI_MAX] =
> {
> {
> - .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[0].lock),
> + .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[0].lock),
> .head = LIST_HEAD_INIT(nmi_desc[0].head),
> },
> {
> - .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[1].lock),
> + .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[1].lock),
> .head = LIST_HEAD_INIT(nmi_desc[1].head),
> },
> {
> - .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[2].lock),
> + .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[2].lock),
> .head = LIST_HEAD_INIT(nmi_desc[2].head),
> },
> {
> - .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock),
> + .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock),
> .head = LIST_HEAD_INIT(nmi_desc[3].head),
> },
>
> @@ -163,7 +163,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
>
> init_irq_work(&action->irq_work, nmi_max_handler);
>
> - spin_lock_irqsave(&desc->lock, flags);
> + raw_spin_lock_irqsave(&desc->lock, flags);
>
> /*
> * Indicate if there are multiple registrations on the
> @@ -181,7 +181,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
> else
> list_add_tail_rcu(&action->list, &desc->head);
>
> - spin_unlock_irqrestore(&desc->lock, flags);
> + raw_spin_unlock_irqrestore(&desc->lock, flags);
> return 0;
> }
> EXPORT_SYMBOL(__register_nmi_handler);
> @@ -192,7 +192,7 @@ void unregister_nmi_handler(unsigned int type, const char *name)
> struct nmiaction *n;
> unsigned long flags;
>
> - spin_lock_irqsave(&desc->lock, flags);
> + raw_spin_lock_irqsave(&desc->lock, flags);
>
> list_for_each_entry_rcu(n, &desc->head, list) {
> /*
> @@ -207,7 +207,7 @@ void unregister_nmi_handler(unsigned int type, const char *name)
> }
> }
>
> - spin_unlock_irqrestore(&desc->lock, flags);
> + raw_spin_unlock_irqrestore(&desc->lock, flags);
> synchronize_rcu();
> }
> EXPORT_SYMBOL_GPL(unregister_nmi_handler);
> --
> 1.8.3.1
>
Commit-ID: c455fd9235b6bd2802db86109cfa0ec105992f68
Gitweb: http://git.kernel.org/tip/c455fd9235b6bd2802db86109cfa0ec105992f68
Author: Scott Wood <[email protected]>
AuthorDate: Mon, 24 Jul 2017 16:32:42 -0500
Committer: Thomas Gleixner <[email protected]>
CommitDate: Wed, 16 Aug 2017 20:40:09 +0200
x86/nmi: Use raw lock
register_nmi_handler() can be called from PREEMPT_RT atomic context
(e.g. wakeup_cpu_via_init_nmi() or native_stop_other_cpus()), and thus
ordinary spinlocks cannot be used.
Signed-off-by: Scott Wood <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Acked-by: Don Zickus <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
---
arch/x86/kernel/nmi.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 446c8aa..35aafc9 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -39,26 +39,26 @@
#include <trace/events/nmi.h>
struct nmi_desc {
- spinlock_t lock;
+ raw_spinlock_t lock;
struct list_head head;
};
static struct nmi_desc nmi_desc[NMI_MAX] =
{
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[0].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[0].lock),
.head = LIST_HEAD_INIT(nmi_desc[0].head),
},
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[1].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[1].lock),
.head = LIST_HEAD_INIT(nmi_desc[1].head),
},
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[2].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[2].lock),
.head = LIST_HEAD_INIT(nmi_desc[2].head),
},
{
- .lock = __SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock),
+ .lock = __RAW_SPIN_LOCK_UNLOCKED(&nmi_desc[3].lock),
.head = LIST_HEAD_INIT(nmi_desc[3].head),
},
@@ -163,7 +163,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
init_irq_work(&action->irq_work, nmi_max_handler);
- spin_lock_irqsave(&desc->lock, flags);
+ raw_spin_lock_irqsave(&desc->lock, flags);
/*
* Indicate if there are multiple registrations on the
@@ -181,7 +181,7 @@ int __register_nmi_handler(unsigned int type, struct nmiaction *action)
else
list_add_tail_rcu(&action->list, &desc->head);
- spin_unlock_irqrestore(&desc->lock, flags);
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
return 0;
}
EXPORT_SYMBOL(__register_nmi_handler);
@@ -192,7 +192,7 @@ void unregister_nmi_handler(unsigned int type, const char *name)
struct nmiaction *n;
unsigned long flags;
- spin_lock_irqsave(&desc->lock, flags);
+ raw_spin_lock_irqsave(&desc->lock, flags);
list_for_each_entry_rcu(n, &desc->head, list) {
/*
@@ -207,7 +207,7 @@ void unregister_nmi_handler(unsigned int type, const char *name)
}
}
- spin_unlock_irqrestore(&desc->lock, flags);
+ raw_spin_unlock_irqrestore(&desc->lock, flags);
synchronize_rcu();
}
EXPORT_SYMBOL_GPL(unregister_nmi_handler);