[PATCH 25/26] kprobes: Convert to raw_spinlocks

John Kacur
2010-01-11T21:28:33Z

Convert locks which cannot be sleeping locks in preempt-rt to raw_spinlocks.

See also dc23e836d8d25fe5aa4057d54dae2094fbc614f6

Signed-off-by: John Kacur <jkacur@redhat.com>
---
include/linux/kprobes.h | 2 +-
kernel/kprobes.c | 34 +++++++++++++++++-----------------
2 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
index 1b672f7..620df87 100644
--- a/include/linux/kprobes.h
+++ b/include/linux/kprobes.h
@@ -170,7 +170,7 @@ struct kretprobe {
int nmissed;
size_t data_size;
struct hlist_head free_instances;
- spinlock_t lock;
+ raw_spinlock_t lock;
};

struct kretprobe_instance {
diff --git a/kernel/kprobes.c b/kernel/kprobes.c
index b7df302..40547e6 100644
--- a/kernel/kprobes.c
+++ b/kernel/kprobes.c
@@ -73,10 +73,10 @@ static bool kprobes_all_disarmed;
static DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
static struct {
- spinlock_t lock ____cacheline_aligned_in_smp;
+ raw_spinlock_t lock ____cacheline_aligned_in_smp;
} kretprobe_table_locks[KPROBE_TABLE_SIZE];

-static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
+static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
{
return &(kretprobe_table_locks[hash].lock);
}
@@ -410,9 +410,9 @@ void __kprobes recycle_rp_inst(struct kretprobe_instance *ri,
hlist_del(&ri->hlist);
INIT_HLIST_NODE(&ri->hlist);
if (likely(rp)) {
- spin_lock(&rp->lock);
+ raw_spin_lock(&rp->lock);
hlist_add_head(&ri->hlist, &rp->free_instances);
- spin_unlock(&rp->lock);
+ raw_spin_unlock(&rp->lock);
} else
/* Unregistering */
hlist_add_head(&ri->hlist, head);
@@ -422,34 +422,34 @@ void __kprobes kretprobe_hash_lock(struct task_struct *tsk,
struct hlist_head **head, unsigned long *flags)
{
unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
- spinlock_t *hlist_lock;
+ raw_spinlock_t *hlist_lock;

*head = &kretprobe_inst_table[hash];
hlist_lock = kretprobe_table_lock_ptr(hash);
- spin_lock_irqsave(hlist_lock, *flags);
+ raw_spin_lock_irqsave(hlist_lock, *flags);
}

static void __kprobes kretprobe_table_lock(unsigned long hash,
unsigned long *flags)
{
- spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
- spin_lock_irqsave(hlist_lock, *flags);
+ raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ raw_spin_lock_irqsave(hlist_lock, *flags);
}

void __kprobes kretprobe_hash_unlock(struct task_struct *tsk,
unsigned long *flags)
{
unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
- spinlock_t *hlist_lock;
+ raw_spinlock_t *hlist_lock;

hlist_lock = kretprobe_table_lock_ptr(hash);
- spin_unlock_irqrestore(hlist_lock, *flags);
+ raw_spin_unlock_irqrestore(hlist_lock, *flags);
}

void __kprobes kretprobe_table_unlock(unsigned long hash, unsigned long *flags)
{
- spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
- spin_unlock_irqrestore(hlist_lock, *flags);
+ raw_spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ raw_spin_unlock_irqrestore(hlist_lock, *flags);
}

/*
@@ -982,12 +982,12 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p,

/*TODO: consider to only swap the RA after the last pre_handler fired */
hash = hash_ptr(current, KPROBE_HASH_BITS);
- spin_lock_irqsave(&rp->lock, flags);
+ raw_spin_lock_irqsave(&rp->lock, flags);
if (!hlist_empty(&rp->free_instances)) {
ri = hlist_entry(rp->free_instances.first,
struct kretprobe_instance, hlist);
hlist_del(&ri->hlist);
- spin_unlock_irqrestore(&rp->lock, flags);
+ raw_spin_unlock_irqrestore(&rp->lock, flags);

ri->rp = rp;
ri->task = current;
@@ -1004,7 +1004,7 @@ static int __kprobes pre_handler_kretprobe(struct kprobe *p,
kretprobe_table_unlock(hash, &flags);
} else {
rp->nmissed++;
- spin_unlock_irqrestore(&rp->lock, flags);
+ raw_spin_unlock_irqrestore(&rp->lock, flags);
}
return 0;
}
@@ -1040,7 +1040,7 @@ int __kprobes register_kretprobe(struct kretprobe *rp)
rp->maxactive = num_possible_cpus();
#endif
}
- spin_lock_init(&rp->lock);
+ raw_spin_lock_init(&rp->lock);
INIT_HLIST_HEAD(&rp->free_instances);
for (i = 0; i < rp->maxactive; i++) {
inst = kmalloc(sizeof(struct kretprobe_instance) +
@@ -1227,7 +1227,7 @@ static int __init init_kprobes(void)
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
INIT_HLIST_HEAD(&kprobe_table[i]);
INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
- spin_lock_init(&(kretprobe_table_locks[i].lock));
+ raw_spin_lock_init(&(kretprobe_table_locks[i].lock));
}

/*
--
1.6.5.2