diff options
Diffstat (limited to 'kernel/trace/trace_stack.c')
| -rw-r--r-- | kernel/trace/trace_stack.c | 40 |
1 files changed, 32 insertions, 8 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 8504ac71e4e..f4bc9b27de5 100644 --- a/kernel/trace/trace_stack.c +++ b/kernel/trace/trace_stack.c @@ -27,8 +27,8 @@ static struct stack_trace max_stack_trace = { }; static unsigned long max_stack_size; -static raw_spinlock_t max_stack_lock = - (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; +static arch_spinlock_t max_stack_lock = + (arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED; static int stack_trace_disabled __read_mostly; static DEFINE_PER_CPU(int, trace_active); @@ -54,7 +54,7 @@ static inline void check_stack(void) return; local_irq_save(flags); - __raw_spin_lock(&max_stack_lock); + arch_spin_lock(&max_stack_lock); /* a race could have already updated it */ if (this_size <= max_stack_size) @@ -103,7 +103,7 @@ static inline void check_stack(void) } out: - __raw_spin_unlock(&max_stack_lock); + arch_spin_unlock(&max_stack_lock); local_irq_restore(flags); } @@ -157,6 +157,7 @@ stack_max_size_write(struct file *filp, const char __user *ubuf, unsigned long val, flags; char buf[64]; int ret; + int cpu; if (count >= sizeof(buf)) return -EINVAL; @@ -171,9 +172,20 @@ stack_max_size_write(struct file *filp, const char __user *ubuf, return ret; local_irq_save(flags); - __raw_spin_lock(&max_stack_lock); + + /* + * In case we trace inside arch_spin_lock() or after (NMI), + * we will cause circular lock, so we also need to increase + * the percpu trace_active here. + */ + cpu = smp_processor_id(); + per_cpu(trace_active, cpu)++; + + arch_spin_lock(&max_stack_lock); *ptr = val; - __raw_spin_unlock(&max_stack_lock); + arch_spin_unlock(&max_stack_lock); + + per_cpu(trace_active, cpu)--; local_irq_restore(flags); return count; @@ -206,8 +218,14 @@ t_next(struct seq_file *m, void *v, loff_t *pos) static void *t_start(struct seq_file *m, loff_t *pos) { + int cpu; + local_irq_disable(); - __raw_spin_lock(&max_stack_lock); + + cpu = smp_processor_id(); + per_cpu(trace_active, cpu)++; + + arch_spin_lock(&max_stack_lock); if (*pos == 0) return SEQ_START_TOKEN; @@ -217,7 +235,13 @@ static void *t_start(struct seq_file *m, loff_t *pos) static void t_stop(struct seq_file *m, void *p) { - __raw_spin_unlock(&max_stack_lock); + int cpu; + + arch_spin_unlock(&max_stack_lock); + + cpu = smp_processor_id(); + per_cpu(trace_active, cpu)--; + local_irq_enable(); } |