forked from Minki/linux
505d3085d7
Fix typos and add the following to the scripts/spelling.txt: overide||override While we are here, fix the doubled "address" in the touched line Documentation/devicetree/bindings/regulator/ti-abb-regulator.txt. Also, fix the comment block style in the touched hunks in drivers/media/dvb-frontends/drx39xyj/drx_driver.h. Link: http://lkml.kernel.org/r/1481573103-11329-21-git-send-email-yamada.masahiro@socionext.com Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
492 lines
11 KiB
C
492 lines
11 KiB
C
/*
|
|
* Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
|
|
*
|
|
*/
|
|
#include <linux/sched/task_stack.h>
|
|
#include <linux/stacktrace.h>
|
|
#include <linux/kallsyms.h>
|
|
#include <linux/seq_file.h>
|
|
#include <linux/spinlock.h>
|
|
#include <linux/uaccess.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/module.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/init.h>
|
|
|
|
#include <asm/setup.h>
|
|
|
|
#include "trace.h"
|
|
|
|
static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] =
|
|
{ [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX };
|
|
unsigned stack_trace_index[STACK_TRACE_ENTRIES];
|
|
|
|
/*
|
|
* Reserve one entry for the passed in ip. This will allow
|
|
* us to remove most or all of the stack size overhead
|
|
* added by the stack tracer itself.
|
|
*/
|
|
struct stack_trace stack_trace_max = {
|
|
.max_entries = STACK_TRACE_ENTRIES - 1,
|
|
.entries = &stack_dump_trace[0],
|
|
};
|
|
|
|
unsigned long stack_trace_max_size;
|
|
arch_spinlock_t stack_trace_max_lock =
|
|
(arch_spinlock_t)__ARCH_SPIN_LOCK_UNLOCKED;
|
|
|
|
static DEFINE_PER_CPU(int, trace_active);
|
|
static DEFINE_MUTEX(stack_sysctl_mutex);
|
|
|
|
int stack_tracer_enabled;
|
|
static int last_stack_tracer_enabled;
|
|
|
|
void stack_trace_print(void)
|
|
{
|
|
long i;
|
|
int size;
|
|
|
|
pr_emerg(" Depth Size Location (%d entries)\n"
|
|
" ----- ---- --------\n",
|
|
stack_trace_max.nr_entries);
|
|
|
|
for (i = 0; i < stack_trace_max.nr_entries; i++) {
|
|
if (stack_dump_trace[i] == ULONG_MAX)
|
|
break;
|
|
if (i+1 == stack_trace_max.nr_entries ||
|
|
stack_dump_trace[i+1] == ULONG_MAX)
|
|
size = stack_trace_index[i];
|
|
else
|
|
size = stack_trace_index[i] - stack_trace_index[i+1];
|
|
|
|
pr_emerg("%3ld) %8d %5d %pS\n", i, stack_trace_index[i],
|
|
size, (void *)stack_dump_trace[i]);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* When arch-specific code overrides this function, the following
|
|
* data should be filled up, assuming stack_trace_max_lock is held to
|
|
* prevent concurrent updates.
|
|
* stack_trace_index[]
|
|
* stack_trace_max
|
|
* stack_trace_max_size
|
|
*/
|
|
void __weak
|
|
check_stack(unsigned long ip, unsigned long *stack)
|
|
{
|
|
unsigned long this_size, flags; unsigned long *p, *top, *start;
|
|
static int tracer_frame;
|
|
int frame_size = ACCESS_ONCE(tracer_frame);
|
|
int i, x;
|
|
|
|
this_size = ((unsigned long)stack) & (THREAD_SIZE-1);
|
|
this_size = THREAD_SIZE - this_size;
|
|
/* Remove the frame of the tracer */
|
|
this_size -= frame_size;
|
|
|
|
if (this_size <= stack_trace_max_size)
|
|
return;
|
|
|
|
/* we do not handle interrupt stacks yet */
|
|
if (!object_is_on_stack(stack))
|
|
return;
|
|
|
|
/* Can't do this from NMI context (can cause deadlocks) */
|
|
if (in_nmi())
|
|
return;
|
|
|
|
local_irq_save(flags);
|
|
arch_spin_lock(&stack_trace_max_lock);
|
|
|
|
/*
|
|
* RCU may not be watching, make it see us.
|
|
* The stack trace code uses rcu_sched.
|
|
*/
|
|
rcu_irq_enter();
|
|
|
|
/* In case another CPU set the tracer_frame on us */
|
|
if (unlikely(!frame_size))
|
|
this_size -= tracer_frame;
|
|
|
|
/* a race could have already updated it */
|
|
if (this_size <= stack_trace_max_size)
|
|
goto out;
|
|
|
|
stack_trace_max_size = this_size;
|
|
|
|
stack_trace_max.nr_entries = 0;
|
|
stack_trace_max.skip = 3;
|
|
|
|
save_stack_trace(&stack_trace_max);
|
|
|
|
/* Skip over the overhead of the stack tracer itself */
|
|
for (i = 0; i < stack_trace_max.nr_entries; i++) {
|
|
if (stack_dump_trace[i] == ip)
|
|
break;
|
|
}
|
|
|
|
/*
|
|
* Some archs may not have the passed in ip in the dump.
|
|
* If that happens, we need to show everything.
|
|
*/
|
|
if (i == stack_trace_max.nr_entries)
|
|
i = 0;
|
|
|
|
/*
|
|
* Now find where in the stack these are.
|
|
*/
|
|
x = 0;
|
|
start = stack;
|
|
top = (unsigned long *)
|
|
(((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE);
|
|
|
|
/*
|
|
* Loop through all the entries. One of the entries may
|
|
* for some reason be missed on the stack, so we may
|
|
* have to account for them. If they are all there, this
|
|
* loop will only happen once. This code only takes place
|
|
* on a new max, so it is far from a fast path.
|
|
*/
|
|
while (i < stack_trace_max.nr_entries) {
|
|
int found = 0;
|
|
|
|
stack_trace_index[x] = this_size;
|
|
p = start;
|
|
|
|
for (; p < top && i < stack_trace_max.nr_entries; p++) {
|
|
if (stack_dump_trace[i] == ULONG_MAX)
|
|
break;
|
|
/*
|
|
* The READ_ONCE_NOCHECK is used to let KASAN know that
|
|
* this is not a stack-out-of-bounds error.
|
|
*/
|
|
if ((READ_ONCE_NOCHECK(*p)) == stack_dump_trace[i]) {
|
|
stack_dump_trace[x] = stack_dump_trace[i++];
|
|
this_size = stack_trace_index[x++] =
|
|
(top - p) * sizeof(unsigned long);
|
|
found = 1;
|
|
/* Start the search from here */
|
|
start = p + 1;
|
|
/*
|
|
* We do not want to show the overhead
|
|
* of the stack tracer stack in the
|
|
* max stack. If we haven't figured
|
|
* out what that is, then figure it out
|
|
* now.
|
|
*/
|
|
if (unlikely(!tracer_frame)) {
|
|
tracer_frame = (p - stack) *
|
|
sizeof(unsigned long);
|
|
stack_trace_max_size -= tracer_frame;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (!found)
|
|
i++;
|
|
}
|
|
|
|
stack_trace_max.nr_entries = x;
|
|
for (; x < i; x++)
|
|
stack_dump_trace[x] = ULONG_MAX;
|
|
|
|
if (task_stack_end_corrupted(current)) {
|
|
stack_trace_print();
|
|
BUG();
|
|
}
|
|
|
|
out:
|
|
rcu_irq_exit();
|
|
arch_spin_unlock(&stack_trace_max_lock);
|
|
local_irq_restore(flags);
|
|
}
|
|
|
|
static void
|
|
stack_trace_call(unsigned long ip, unsigned long parent_ip,
|
|
struct ftrace_ops *op, struct pt_regs *pt_regs)
|
|
{
|
|
unsigned long stack;
|
|
int cpu;
|
|
|
|
preempt_disable_notrace();
|
|
|
|
cpu = raw_smp_processor_id();
|
|
/* no atomic needed, we only modify this variable by this cpu */
|
|
if (per_cpu(trace_active, cpu)++ != 0)
|
|
goto out;
|
|
|
|
ip += MCOUNT_INSN_SIZE;
|
|
|
|
check_stack(ip, &stack);
|
|
|
|
out:
|
|
per_cpu(trace_active, cpu)--;
|
|
/* prevent recursion in schedule */
|
|
preempt_enable_notrace();
|
|
}
|
|
|
|
static struct ftrace_ops trace_ops __read_mostly =
|
|
{
|
|
.func = stack_trace_call,
|
|
.flags = FTRACE_OPS_FL_RECURSION_SAFE,
|
|
};
|
|
|
|
static ssize_t
|
|
stack_max_size_read(struct file *filp, char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
unsigned long *ptr = filp->private_data;
|
|
char buf[64];
|
|
int r;
|
|
|
|
r = snprintf(buf, sizeof(buf), "%ld\n", *ptr);
|
|
if (r > sizeof(buf))
|
|
r = sizeof(buf);
|
|
return simple_read_from_buffer(ubuf, count, ppos, buf, r);
|
|
}
|
|
|
|
static ssize_t
|
|
stack_max_size_write(struct file *filp, const char __user *ubuf,
|
|
size_t count, loff_t *ppos)
|
|
{
|
|
long *ptr = filp->private_data;
|
|
unsigned long val, flags;
|
|
int ret;
|
|
int cpu;
|
|
|
|
ret = kstrtoul_from_user(ubuf, count, 10, &val);
|
|
if (ret)
|
|
return ret;
|
|
|
|
local_irq_save(flags);
|
|
|
|
/*
|
|
* 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(&stack_trace_max_lock);
|
|
*ptr = val;
|
|
arch_spin_unlock(&stack_trace_max_lock);
|
|
|
|
per_cpu(trace_active, cpu)--;
|
|
local_irq_restore(flags);
|
|
|
|
return count;
|
|
}
|
|
|
|
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 *
|
|
__next(struct seq_file *m, loff_t *pos)
|
|
{
|
|
long n = *pos - 1;
|
|
|
|
if (n > stack_trace_max.nr_entries || stack_dump_trace[n] == ULONG_MAX)
|
|
return NULL;
|
|
|
|
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)
|
|
{
|
|
int cpu;
|
|
|
|
local_irq_disable();
|
|
|
|
cpu = smp_processor_id();
|
|
per_cpu(trace_active, cpu)++;
|
|
|
|
arch_spin_lock(&stack_trace_max_lock);
|
|
|
|
if (*pos == 0)
|
|
return SEQ_START_TOKEN;
|
|
|
|
return __next(m, pos);
|
|
}
|
|
|
|
static void t_stop(struct seq_file *m, void *p)
|
|
{
|
|
int cpu;
|
|
|
|
arch_spin_unlock(&stack_trace_max_lock);
|
|
|
|
cpu = smp_processor_id();
|
|
per_cpu(trace_active, cpu)--;
|
|
|
|
local_irq_enable();
|
|
}
|
|
|
|
static void trace_lookup_stack(struct seq_file *m, long i)
|
|
{
|
|
unsigned long addr = stack_dump_trace[i];
|
|
|
|
seq_printf(m, "%pS\n", (void *)addr);
|
|
}
|
|
|
|
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)
|
|
{
|
|
long i;
|
|
int size;
|
|
|
|
if (v == SEQ_START_TOKEN) {
|
|
seq_printf(m, " Depth Size Location"
|
|
" (%d entries)\n"
|
|
" ----- ---- --------\n",
|
|
stack_trace_max.nr_entries);
|
|
|
|
if (!stack_tracer_enabled && !stack_trace_max_size)
|
|
print_disabled(m);
|
|
|
|
return 0;
|
|
}
|
|
|
|
i = *(long *)v;
|
|
|
|
if (i >= stack_trace_max.nr_entries ||
|
|
stack_dump_trace[i] == ULONG_MAX)
|
|
return 0;
|
|
|
|
if (i+1 == stack_trace_max.nr_entries ||
|
|
stack_dump_trace[i+1] == ULONG_MAX)
|
|
size = stack_trace_index[i];
|
|
else
|
|
size = stack_trace_index[i] - stack_trace_index[i+1];
|
|
|
|
seq_printf(m, "%3ld) %8d %5d ", i, stack_trace_index[i], size);
|
|
|
|
trace_lookup_stack(m, i);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct seq_operations stack_trace_seq_ops = {
|
|
.start = t_start,
|
|
.next = t_next,
|
|
.stop = t_stop,
|
|
.show = t_show,
|
|
};
|
|
|
|
static int stack_trace_open(struct inode *inode, struct file *file)
|
|
{
|
|
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,
|
|
};
|
|
|
|
static int
|
|
stack_trace_filter_open(struct inode *inode, struct file *file)
|
|
{
|
|
return ftrace_regex_open(&trace_ops, FTRACE_ITER_FILTER,
|
|
inode, file);
|
|
}
|
|
|
|
static const struct file_operations stack_trace_filter_fops = {
|
|
.open = stack_trace_filter_open,
|
|
.read = seq_read,
|
|
.write = ftrace_filter_write,
|
|
.llseek = tracing_lseek,
|
|
.release = ftrace_regex_release,
|
|
};
|
|
|
|
int
|
|
stack_trace_sysctl(struct ctl_table *table, int write,
|
|
void __user *buffer, size_t *lenp,
|
|
loff_t *ppos)
|
|
{
|
|
int ret;
|
|
|
|
mutex_lock(&stack_sysctl_mutex);
|
|
|
|
ret = proc_dointvec(table, write, buffer, lenp, ppos);
|
|
|
|
if (ret || !write ||
|
|
(last_stack_tracer_enabled == !!stack_tracer_enabled))
|
|
goto out;
|
|
|
|
last_stack_tracer_enabled = !!stack_tracer_enabled;
|
|
|
|
if (stack_tracer_enabled)
|
|
register_ftrace_function(&trace_ops);
|
|
else
|
|
unregister_ftrace_function(&trace_ops);
|
|
|
|
out:
|
|
mutex_unlock(&stack_sysctl_mutex);
|
|
return ret;
|
|
}
|
|
|
|
static char stack_trace_filter_buf[COMMAND_LINE_SIZE+1] __initdata;
|
|
|
|
static __init int enable_stacktrace(char *str)
|
|
{
|
|
if (strncmp(str, "_filter=", 8) == 0)
|
|
strncpy(stack_trace_filter_buf, str+8, COMMAND_LINE_SIZE);
|
|
|
|
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;
|
|
|
|
d_tracer = tracing_init_dentry();
|
|
if (IS_ERR(d_tracer))
|
|
return 0;
|
|
|
|
trace_create_file("stack_max_size", 0644, d_tracer,
|
|
&stack_trace_max_size, &stack_max_size_fops);
|
|
|
|
trace_create_file("stack_trace", 0444, d_tracer,
|
|
NULL, &stack_trace_fops);
|
|
|
|
trace_create_file("stack_trace_filter", 0444, d_tracer,
|
|
NULL, &stack_trace_filter_fops);
|
|
|
|
if (stack_trace_filter_buf[0])
|
|
ftrace_set_early_filter(&trace_ops, stack_trace_filter_buf, 1);
|
|
|
|
if (stack_tracer_enabled)
|
|
register_ftrace_function(&trace_ops);
|
|
|
|
return 0;
|
|
}
|
|
|
|
device_initcall(stack_trace_init);
|