diff options
Diffstat (limited to 'kernel/trace/trace_stack.c')
| -rw-r--r-- | kernel/trace/trace_stack.c | 103 |
1 files changed, 54 insertions, 49 deletions
diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c index 2d7aebd71db..4c5dead0c23 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) @@ -103,19 +103,19 @@ static inline void check_stack(void) } out: - __raw_spin_unlock(&max_stack_lock); + arch_spin_unlock(&max_stack_lock); local_irq_restore(flags); } static void stack_trace_call(unsigned long ip, unsigned long parent_ip) { - int cpu, resched; + int cpu; if (unlikely(!ftrace_enabled || stack_trace_disabled)) return; - resched = ftrace_preempt_disable(); + preempt_disable_notrace(); cpu = raw_smp_processor_id(); /* no atomic needed, we only modify this variable by this cpu */ @@ -127,7 +127,7 @@ stack_trace_call(unsigned long ip, unsigned long parent_ip) out: per_cpu(trace_active, cpu)--; /* prevent recursion in schedule */ - ftrace_preempt_enable(resched); + preempt_enable_notrace(); } static struct ftrace_ops trace_ops __read_mostly = @@ -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; @@ -183,66 +195,62 @@ static const struct file_operations stack_max_size_fops = { .open = tracing_open_generic, .read = stack_max_size_read, .write = stack_max_size_write, + .llseek = default_llseek, }; static void * -t_next(struct seq_file *m, void *v, loff_t *pos) +__next(struct seq_file *m, loff_t *pos) { - long i; + long n = *pos - 1; - (*pos)++; - - if (v == SEQ_START_TOKEN) - i = 0; - else { - i = *(long *)v; - i++; - } - - if (i >= max_stack_trace.nr_entries || - stack_dump_trace[i] == ULONG_MAX) + if (n >= max_stack_trace.nr_entries || stack_dump_trace[n] == ULONG_MAX) return NULL; - m->private = (void *)i; - + m->private = (void *)n; return &m->private; } +static void * +t_next(struct seq_file *m, void *v, loff_t *pos) +{ + (*pos)++; + return __next(m, pos); +} + static void *t_start(struct seq_file *m, loff_t *pos) { - void *t = SEQ_START_TOKEN; - loff_t l = 0; + 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; - for (; t && l < *pos; t = t_next(m, t, &l)) - ; - - return t; + return __next(m, 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(); } static int trace_lookup_stack(struct seq_file *m, long i) { unsigned long addr = stack_dump_trace[i]; -#ifdef CONFIG_KALLSYMS - char str[KSYM_SYMBOL_LEN]; - - sprint_symbol(str, addr); - return seq_printf(m, "%s\n", str); -#else - return seq_printf(m, "%p\n", (void*)addr); -#endif + return seq_printf(m, "%pS\n", (void *)addr); } static void print_disabled(struct seq_file *m) @@ -301,35 +309,32 @@ static const struct seq_operations stack_trace_seq_ops = { static int stack_trace_open(struct inode *inode, struct file *file) { - int ret; - - ret = seq_open(file, &stack_trace_seq_ops); - - return ret; + return seq_open(file, &stack_trace_seq_ops); } static const struct file_operations stack_trace_fops = { .open = stack_trace_open, .read = seq_read, .llseek = seq_lseek, + .release = seq_release, }; int stack_trace_sysctl(struct ctl_table *table, int write, - struct file *file, void __user *buffer, size_t *lenp, + void __user *buffer, size_t *lenp, loff_t *ppos) { int ret; mutex_lock(&stack_sysctl_mutex); - ret = proc_dointvec(table, write, file, buffer, lenp, ppos); + ret = proc_dointvec(table, write, buffer, lenp, ppos); if (ret || !write || - (last_stack_tracer_enabled == stack_tracer_enabled)) + (last_stack_tracer_enabled == !!stack_tracer_enabled)) goto out; - last_stack_tracer_enabled = stack_tracer_enabled; + last_stack_tracer_enabled = !!stack_tracer_enabled; if (stack_tracer_enabled) register_ftrace_function(&trace_ops); |