};
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);
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)
}
out:
- __raw_spin_unlock(&max_stack_lock);
+ arch_spin_unlock(&max_stack_lock);
local_irq_restore(flags);
}
unsigned long val, flags;
char buf[64];
int ret;
+ int cpu;
if (count >= sizeof(buf))
return -EINVAL;
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;
};
static void *
-t_next(struct seq_file *m, void *v, loff_t *pos)
+__next(struct seq_file *m, loff_t *pos)
{
- long i;
-
- (*pos)++;
+ long n = *pos - 1;
- 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, "%pF\n", (void *)addr);
+}
- return seq_printf(m, "%s\n", str);
-#else
- return seq_printf(m, "%p\n", (void*)addr);
-#endif
+static void print_disabled(struct seq_file *m)
+{
+ seq_puts(m, "#\n"
+ "# Stack tracer disabled\n"
+ "#\n"
+ "# To enable the stack tracer, either add 'stacktrace' to the\n"
+ "# kernel command line\n"
+ "# or 'echo 1 > /proc/sys/kernel/stack_tracer_enabled'\n"
+ "#\n");
}
static int t_show(struct seq_file *m, void *v)
int size;
if (v == SEQ_START_TOKEN) {
- seq_printf(m, " Depth Size Location"
+ seq_printf(m, " Depth Size Location"
" (%d entries)\n"
- " ----- ---- --------\n",
- max_stack_trace.nr_entries);
+ " ----- ---- --------\n",
+ max_stack_trace.nr_entries - 1);
+
+ if (!stack_tracer_enabled && !max_stack_size)
+ print_disabled(m);
+
return 0;
}
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);
return ret;
}
-static int start_stack_trace __initdata;
-
static __init int enable_stacktrace(char *str)
{
- start_stack_trace = 1;
+ stack_tracer_enabled = 1;
+ last_stack_tracer_enabled = 1;
return 1;
}
__setup("stacktrace", enable_stacktrace);
static __init int stack_trace_init(void)
{
struct dentry *d_tracer;
- struct dentry *entry;
d_tracer = tracing_init_dentry();
- entry = debugfs_create_file("stack_max_size", 0644, d_tracer,
- &max_stack_size, &stack_max_size_fops);
- if (!entry)
- pr_warning("Could not create debugfs 'stack_max_size' entry\n");
+ trace_create_file("stack_max_size", 0644, d_tracer,
+ &max_stack_size, &stack_max_size_fops);
- entry = debugfs_create_file("stack_trace", 0444, d_tracer,
- NULL, &stack_trace_fops);
- if (!entry)
- pr_warning("Could not create debugfs 'stack_trace' entry\n");
+ trace_create_file("stack_trace", 0444, d_tracer,
+ NULL, &stack_trace_fops);
- if (start_stack_trace) {
+ if (stack_tracer_enabled)
register_ftrace_function(&trace_ops);
- stack_tracer_enabled = 1;
- }
return 0;
}
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff