[linux-2.6-block.git] / lib / fault-inject.c

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/prandom.h>
#include <linux/debugfs.h>
#include <linux/sched.h>
#include <linux/stat.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/export.h>
#include <linux/interrupt.h>
#include <linux/stacktrace.h>
#include <linux/fault-inject.h>

/*
 * The should_fail() functions use prandom instead of the normal Linux RNG
 * since they don't need cryptographically secure random numbers.
 */
static DEFINE_PER_CPU(struct rnd_state, fault_rnd_state);

static u32 fault_prandom_u32_below_100(void)
{
	struct rnd_state *state;
	u32 res;

	state = &get_cpu_var(fault_rnd_state);
	res = prandom_u32_state(state);
	put_cpu_var(fault_rnd_state);

	return res % 100;
}

/*
 * setup_fault_attr() is a helper function for various __setup handlers, so it
 * returns 0 on error, because that is what __setup handlers do.
 */
int setup_fault_attr(struct fault_attr *attr, char *str)
{
	unsigned long probability;
	unsigned long interval;
	int times;
	int space;

	/* "<interval>,<probability>,<space>,<times>" */
	if (sscanf(str, "%lu,%lu,%d,%d",
			&interval, &probability, &space, &times) < 4) {
		printk(KERN_WARNING
			"FAULT_INJECTION: failed to parse arguments\n");
		return 0;
	}

	prandom_init_once(&fault_rnd_state);

	attr->probability = probability;
	attr->interval = interval;
	atomic_set(&attr->times, times);
	atomic_set(&attr->space, space);

	return 1;
}
EXPORT_SYMBOL_GPL(setup_fault_attr);

static void fail_dump(struct fault_attr *attr)
{
	if (attr->verbose > 0 && __ratelimit(&attr->ratelimit_state)) {
		printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure.\n"
		       "name %pd, interval %lu, probability %lu, "
		       "space %d, times %d\n", attr->dname,
		       attr->interval, attr->probability,
		       atomic_read(&attr->space),
		       atomic_read(&attr->times));
		if (attr->verbose > 1)
			dump_stack();
	}
}

#define atomic_dec_not_zero(v)		atomic_add_unless((v), -1, 0)

static bool fail_task(struct fault_attr *attr, struct task_struct *task)
{
	return in_task() && task->make_it_fail;
}

#define MAX_STACK_TRACE_DEPTH 32

#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER

static bool fail_stacktrace(struct fault_attr *attr)
{
	int depth = attr->stacktrace_depth;
	unsigned long entries[MAX_STACK_TRACE_DEPTH];
	int n, nr_entries;
	bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX);

	if (depth == 0 || (found && !attr->reject_start && !attr->reject_end))
		return found;

	nr_entries = stack_trace_save(entries, depth, 1);
	for (n = 0; n < nr_entries; n++) {
		if (attr->reject_start <= entries[n] &&
			       entries[n] < attr->reject_end)
			return false;
		if (attr->require_start <= entries[n] &&
			       entries[n] < attr->require_end)
			found = true;
	}
	return found;
}

#else

static inline bool fail_stacktrace(struct fault_attr *attr)
{
	return true;
}

#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */

/*
 * This code is stolen from failmalloc-1.0
 * http://www.nongnu.org/failmalloc/
 */

bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
{
	bool stack_checked = false;

	if (in_task()) {
		unsigned int fail_nth = READ_ONCE(current->fail_nth);

		if (fail_nth) {
			if (!fail_stacktrace(attr))
				return false;

			stack_checked = true;
			fail_nth--;
			WRITE_ONCE(current->fail_nth, fail_nth);
			if (!fail_nth)
				goto fail;

			return false;
		}
	}

	/* No need to check any other properties if the probability is 0 */
	if (attr->probability == 0)
		return false;

	if (attr->task_filter && !fail_task(attr, current))
		return false;

	if (atomic_read(&attr->times) == 0)
		return false;

	if (!stack_checked && !fail_stacktrace(attr))
		return false;

	if (atomic_read(&attr->space) > size) {
		atomic_sub(size, &attr->space);
		return false;
	}

	if (attr->interval > 1) {
		attr->count++;
		if (attr->count % attr->interval)
			return false;
	}

	if (attr->probability <= fault_prandom_u32_below_100())
		return false;

fail:
	if (!(flags & FAULT_NOWARN))
		fail_dump(attr);

	if (atomic_read(&attr->times) != -1)
		atomic_dec_not_zero(&attr->times);

	return true;
}

bool should_fail(struct fault_attr *attr, ssize_t size)
{
	return should_fail_ex(attr, size, 0);
}
EXPORT_SYMBOL_GPL(should_fail);

#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS

static int debugfs_ul_set(void *data, u64 val)
{
	*(unsigned long *)data = val;
	return 0;
}

static int debugfs_ul_get(void *data, u64 *val)
{
	*val = *(unsigned long *)data;
	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n");

static void debugfs_create_ul(const char *name, umode_t mode,
			      struct dentry *parent, unsigned long *value)
{
	debugfs_create_file(name, mode, parent, value, &fops_ul);
}

#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER

static int debugfs_stacktrace_depth_set(void *data, u64 val)
{
	*(unsigned long *)data =
		min_t(unsigned long, val, MAX_STACK_TRACE_DEPTH);

	return 0;
}

DEFINE_SIMPLE_ATTRIBUTE(fops_stacktrace_depth, debugfs_ul_get,
			debugfs_stacktrace_depth_set, "%llu\n");

static void debugfs_create_stacktrace_depth(const char *name, umode_t mode,
					    struct dentry *parent,
					    unsigned long *value)
{
	debugfs_create_file(name, mode, parent, value, &fops_stacktrace_depth);
}

#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */

struct dentry *fault_create_debugfs_attr(const char *name,
			struct dentry *parent, struct fault_attr *attr)
{
	umode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
	struct dentry *dir;

	dir = debugfs_create_dir(name, parent);
	if (IS_ERR(dir))
		return dir;

	prandom_init_once(&fault_rnd_state);

	debugfs_create_ul("probability", mode, dir, &attr->probability);
	debugfs_create_ul("interval", mode, dir, &attr->interval);
	debugfs_create_atomic_t("times", mode, dir, &attr->times);
	debugfs_create_atomic_t("space", mode, dir, &attr->space);
	debugfs_create_ul("verbose", mode, dir, &attr->verbose);
	debugfs_create_u32("verbose_ratelimit_interval_ms", mode, dir,
			   &attr->ratelimit_state.interval);
	debugfs_create_u32("verbose_ratelimit_burst", mode, dir,
			   &attr->ratelimit_state.burst);
	debugfs_create_bool("task-filter", mode, dir, &attr->task_filter);

#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
	debugfs_create_stacktrace_depth("stacktrace-depth", mode, dir,
					&attr->stacktrace_depth);
	debugfs_create_xul("require-start", mode, dir, &attr->require_start);
	debugfs_create_xul("require-end", mode, dir, &attr->require_end);
	debugfs_create_xul("reject-start", mode, dir, &attr->reject_start);
	debugfs_create_xul("reject-end", mode, dir, &attr->reject_end);
#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */

	attr->dname = dget(dir);
	return dir;
}
EXPORT_SYMBOL_GPL(fault_create_debugfs_attr);

#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */

#ifdef CONFIG_FAULT_INJECTION_CONFIGFS

/* These configfs attribute utilities are copied from drivers/block/null_blk/main.c */

static ssize_t fault_uint_attr_show(unsigned int val, char *page)
{
	return snprintf(page, PAGE_SIZE, "%u\n", val);
}

static ssize_t fault_ulong_attr_show(unsigned long val, char *page)
{
	return snprintf(page, PAGE_SIZE, "%lu\n", val);
}

static ssize_t fault_bool_attr_show(bool val, char *page)
{
	return snprintf(page, PAGE_SIZE, "%u\n", val);
}

static ssize_t fault_atomic_t_attr_show(atomic_t val, char *page)
{
	return snprintf(page, PAGE_SIZE, "%d\n", atomic_read(&val));
}

static ssize_t fault_uint_attr_store(unsigned int *val, const char *page, size_t count)
{
	unsigned int tmp;
	int result;

	result = kstrtouint(page, 0, &tmp);
	if (result < 0)
		return result;

	*val = tmp;
	return count;
}

static ssize_t fault_ulong_attr_store(unsigned long *val, const char *page, size_t count)
{
	int result;
	unsigned long tmp;

	result = kstrtoul(page, 0, &tmp);
	if (result < 0)
		return result;

	*val = tmp;
	return count;
}

static ssize_t fault_bool_attr_store(bool *val, const char *page, size_t count)
{
	bool tmp;
	int result;

	result = kstrtobool(page, &tmp);
	if (result < 0)
		return result;

	*val = tmp;
	return count;
}

static ssize_t fault_atomic_t_attr_store(atomic_t *val, const char *page, size_t count)
{
	int tmp;
	int result;

	result = kstrtoint(page, 0, &tmp);
	if (result < 0)
		return result;

	atomic_set(val, tmp);
	return count;
}

#define CONFIGFS_ATTR_NAMED(_pfx, _name, _attr_name)	\
static struct configfs_attribute _pfx##attr_##_name = {	\
	.ca_name	= _attr_name,			\
	.ca_mode	= 0644,				\
	.ca_owner	= THIS_MODULE,			\
	.show		= _pfx##_name##_show,		\
	.store		= _pfx##_name##_store,		\
}

static struct fault_config *to_fault_config(struct config_item *item)
{
	return container_of(to_config_group(item), struct fault_config, group);
}

#define FAULT_CONFIGFS_ATTR_NAMED(NAME, ATTR_NAME, MEMBER, TYPE)				\
static ssize_t fault_##NAME##_show(struct config_item *item, char *page)			\
{												\
	return fault_##TYPE##_attr_show(to_fault_config(item)->attr.MEMBER, page);		\
}												\
static ssize_t fault_##NAME##_store(struct config_item *item, const char *page, size_t count)	\
{												\
	struct fault_config *config = to_fault_config(item);					\
	return fault_##TYPE##_attr_store(&config->attr.MEMBER, page, count);			\
}												\
CONFIGFS_ATTR_NAMED(fault_, NAME, ATTR_NAME)

#define FAULT_CONFIGFS_ATTR(NAME, TYPE)	\
	FAULT_CONFIGFS_ATTR_NAMED(NAME, __stringify(NAME), NAME, TYPE)

FAULT_CONFIGFS_ATTR(probability, ulong);
FAULT_CONFIGFS_ATTR(interval, ulong);
FAULT_CONFIGFS_ATTR(times, atomic_t);
FAULT_CONFIGFS_ATTR(space, atomic_t);
FAULT_CONFIGFS_ATTR(verbose, ulong);
FAULT_CONFIGFS_ATTR_NAMED(ratelimit_interval, "verbose_ratelimit_interval_ms",
		ratelimit_state.interval, uint);
FAULT_CONFIGFS_ATTR_NAMED(ratelimit_burst, "verbose_ratelimit_burst",
		ratelimit_state.burst, uint);
FAULT_CONFIGFS_ATTR_NAMED(task_filter, "task-filter", task_filter, bool);

#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER

static ssize_t fault_stacktrace_depth_show(struct config_item *item, char *page)
{
	return fault_ulong_attr_show(to_fault_config(item)->attr.stacktrace_depth, page);
}

static ssize_t fault_stacktrace_depth_store(struct config_item *item, const char *page,
		size_t count)
{
	int result;
	unsigned long tmp;

	result = kstrtoul(page, 0, &tmp);
	if (result < 0)
		return result;

	to_fault_config(item)->attr.stacktrace_depth =
		min_t(unsigned long, tmp, MAX_STACK_TRACE_DEPTH);

	return count;
}

CONFIGFS_ATTR_NAMED(fault_, stacktrace_depth, "stacktrace-depth");

static ssize_t fault_xul_attr_show(unsigned long val, char *page)
{
	return snprintf(page, PAGE_SIZE,
			sizeof(val) == sizeof(u32) ? "0x%08lx\n" : "0x%016lx\n", val);
}

static ssize_t fault_xul_attr_store(unsigned long *val, const char *page, size_t count)
{
	return fault_ulong_attr_store(val, page, count);
}

FAULT_CONFIGFS_ATTR_NAMED(require_start, "require-start", require_start, xul);
FAULT_CONFIGFS_ATTR_NAMED(require_end, "require-end", require_end, xul);
FAULT_CONFIGFS_ATTR_NAMED(reject_start, "reject-start", reject_start, xul);
FAULT_CONFIGFS_ATTR_NAMED(reject_end, "reject-end", reject_end, xul);

#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */

static struct configfs_attribute *fault_config_attrs[] = {
	&fault_attr_probability,
	&fault_attr_interval,
	&fault_attr_times,
	&fault_attr_space,
	&fault_attr_verbose,
	&fault_attr_ratelimit_interval,
	&fault_attr_ratelimit_burst,
	&fault_attr_task_filter,
#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
	&fault_attr_stacktrace_depth,
	&fault_attr_require_start,
	&fault_attr_require_end,
	&fault_attr_reject_start,
	&fault_attr_reject_end,
#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
	NULL,
};

static const struct config_item_type fault_config_type = {
	.ct_attrs	= fault_config_attrs,
	.ct_owner	= THIS_MODULE,
};

void fault_config_init(struct fault_config *config, const char *name)
{
	prandom_init_once(&fault_rnd_state);

	config_group_init_type_name(&config->group, name, &fault_config_type);
}
EXPORT_SYMBOL_GPL(fault_config_init);

#endif /* CONFIG_FAULT_INJECTION_CONFIGFS */
Commit	Line	Data
457c8996	1	// SPDX-License-Identifier: GPL-2.0-only
6ff1cb35 AM	2	#include <linux/kernel.h>
6ff1cb35 AM	3	#include <linux/init.h>
e9bc360b	4	#include <linux/prandom.h>
6ce2082f	5	#include <linux/debugfs.h>
d43c36dc	6	#include <linux/sched.h>
6ff1cb35 AM	7	#include <linux/stat.h>
	8	#include <linux/types.h>
	9	#include <linux/fs.h>
8bc3bcc9	10	#include <linux/export.h>
f4f154fd	11	#include <linux/interrupt.h>
329409ae	12	#include <linux/stacktrace.h>
6ff1cb35 AM	13	#include <linux/fault-inject.h>
6ff1cb35 AM	14
e9bc360b AM	15	/*
	16	* The should_fail() functions use prandom instead of the normal Linux RNG
	17	* since they don't need cryptographically secure random numbers.
	18	*/
	19	static DEFINE_PER_CPU(struct rnd_state, fault_rnd_state);
	20
	21	static u32 fault_prandom_u32_below_100(void)
	22	{
	23	struct rnd_state *state;
	24	u32 res;
	25
	26	state = &get_cpu_var(fault_rnd_state);
	27	res = prandom_u32_state(state);
	28	put_cpu_var(fault_rnd_state);
	29
	30	return res % 100;
	31	}
	32
6ff1cb35 AM	33	/*
	34	* setup_fault_attr() is a helper function for various __setup handlers, so it
	35	* returns 0 on error, because that is what __setup handlers do.
	36	*/
6cba00ea	37	int setup_fault_attr(struct fault_attr attr, char str)
6ff1cb35 AM	38	{
	39	unsigned long probability;
	40	unsigned long interval;
	41	int times;
	42	int space;
	43
	44	/* "<interval>,<probability>,<space>,<times>" */
	45	if (sscanf(str, "%lu,%lu,%d,%d",
	46	&interval, &probability, &space, &times) < 4) {
	47	printk(KERN_WARNING
	48	"FAULT_INJECTION: failed to parse arguments\n");
	49	return 0;
	50	}
	51
e9bc360b AM	52	prandom_init_once(&fault_rnd_state);
e9bc360b AM	53
6ff1cb35 AM	54	attr->probability = probability;
	55	attr->interval = interval;
	56	atomic_set(&attr->times, times);
	57	atomic_set(&attr->space, space);
	58
	59	return 1;
	60	}
6cba00ea	61	EXPORT_SYMBOL_GPL(setup_fault_attr);
6ff1cb35 AM	62
	63	static void fail_dump(struct fault_attr *attr)
	64	{
6adc4a22 DM	65	if (attr->verbose > 0 && __ratelimit(&attr->ratelimit_state)) {
	66	printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure.\n"
	67	"name %pd, interval %lu, probability %lu, "
	68	"space %d, times %d\n", attr->dname,
bb387002	69	attr->interval, attr->probability,
6adc4a22 DM	70	atomic_read(&attr->space),
	71	atomic_read(&attr->times));
	72	if (attr->verbose > 1)
	73	dump_stack();
	74	}
6ff1cb35 AM	75	}
	76
	77	#define atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0)
	78
08b3df2d	79	static bool fail_task(struct fault_attr attr, struct task_struct task)
f4f154fd	80	{
f2ad37da	81	return in_task() && task->make_it_fail;
f4f154fd AM	82	}
f4f154fd AM	83
a124c28e DM	84	#define MAX_STACK_TRACE_DEPTH 32
a124c28e DM	85
1df49008	86	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
329409ae	87
08b3df2d	88	static bool fail_stacktrace(struct fault_attr *attr)
329409ae	89	{
329409ae AM	90	int depth = attr->stacktrace_depth;
329409ae AM	91	unsigned long entries[MAX_STACK_TRACE_DEPTH];
30191250	92	int n, nr_entries;
329409ae AM	93	bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX);
329409ae AM	94
4acb9e51	95	if (depth == 0 \|\| (found && !attr->reject_start && !attr->reject_end))
329409ae AM	96	return found;
329409ae AM	97
30191250 TG	98	nr_entries = stack_trace_save(entries, depth, 1);
30191250 TG	99	for (n = 0; n < nr_entries; n++) {
329409ae AM	100	if (attr->reject_start <= entries[n] &&
329409ae AM	101	entries[n] < attr->reject_end)
08b3df2d	102	return false;
329409ae AM	103	if (attr->require_start <= entries[n] &&
329409ae AM	104	entries[n] < attr->require_end)
08b3df2d	105	found = true;
329409ae AM	106	}
	107	return found;
	108	}
	109
	110	#else
	111
08b3df2d	112	static inline bool fail_stacktrace(struct fault_attr *attr)
329409ae	113	{
1df49008	114	return true;
329409ae AM	115	}
329409ae AM	116
1df49008	117	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
329409ae	118
6ff1cb35 AM	119	/*
	120	* This code is stolen from failmalloc-1.0
	121	* http://www.nongnu.org/failmalloc/
	122	*/
	123
ea4452de	124	bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
6ff1cb35	125	{
f9eeef59 WY	126	bool stack_checked = false;
f9eeef59 WY	127
1203c8e6 AM	128	if (in_task()) {
	129	unsigned int fail_nth = READ_ONCE(current->fail_nth);
	130
9eeb52ae	131	if (fail_nth) {
f9eeef59 WY	132	if (!fail_stacktrace(attr))
	133	return false;
	134
	135	stack_checked = true;
9b4fb5ce WD	136	fail_nth--;
	137	WRITE_ONCE(current->fail_nth, fail_nth);
	138	if (!fail_nth)
9eeb52ae	139	goto fail;
1203c8e6	140
9eeb52ae AM	141	return false;
9eeb52ae AM	142	}
e41d5818 DV	143	}
e41d5818 DV	144
f39cdaeb AB	145	/* No need to check any other properties if the probability is 0 */
	146	if (attr->probability == 0)
	147	return false;
	148
f4f154fd	149	if (attr->task_filter && !fail_task(attr, current))
08b3df2d	150	return false;
f4f154fd	151
6ff1cb35	152	if (atomic_read(&attr->times) == 0)
08b3df2d	153	return false;
6ff1cb35	154
f9eeef59 WY	155	if (!stack_checked && !fail_stacktrace(attr))
	156	return false;
	157
6ff1cb35 AM	158	if (atomic_read(&attr->space) > size) {
6ff1cb35 AM	159	atomic_sub(size, &attr->space);
08b3df2d	160	return false;
6ff1cb35 AM	161	}
	162
	163	if (attr->interval > 1) {
	164	attr->count++;
	165	if (attr->count % attr->interval)
08b3df2d	166	return false;
6ff1cb35 AM	167	}
6ff1cb35 AM	168
e9bc360b	169	if (attr->probability <= fault_prandom_u32_below_100())
f1729c28	170	return false;
6ff1cb35	171
e41d5818	172	fail:
ea4452de QZ	173	if (!(flags & FAULT_NOWARN))
ea4452de QZ	174	fail_dump(attr);
6ff1cb35 AM	175
	176	if (atomic_read(&attr->times) != -1)
	177	atomic_dec_not_zero(&attr->times);
	178
08b3df2d	179	return true;
6ff1cb35	180	}
ea4452de QZ	181
	182	bool should_fail(struct fault_attr *attr, ssize_t size)
	183	{
	184	return should_fail_ex(attr, size, 0);
	185	}
df87ecbf	186	EXPORT_SYMBOL_GPL(should_fail);
6ff1cb35 AM	187
	188	#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
	189
8b88b099	190	static int debugfs_ul_set(void *data, u64 val)
6ff1cb35 AM	191	{
6ff1cb35 AM	192	(unsigned long )data = val;
8b88b099	193	return 0;
6ff1cb35 AM	194	}
6ff1cb35 AM	195
8b88b099	196	static int debugfs_ul_get(void data, u64 val)
6ff1cb35	197	{
8b88b099 CH	198	val = (unsigned long *)data;
8b88b099 CH	199	return 0;
6ff1cb35 AM	200	}
	201
	202	DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n");
	203
053cf510 GKH	204	static void debugfs_create_ul(const char *name, umode_t mode,
053cf510 GKH	205	struct dentry parent, unsigned long value)
6ff1cb35	206	{
053cf510	207	debugfs_create_file(name, mode, parent, value, &fops_ul);
6ff1cb35 AM	208	}
6ff1cb35 AM	209
6ddb23c7	210	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
a124c28e	211
8307fc25 AM	212	static int debugfs_stacktrace_depth_set(void *data, u64 val)
	213	{
	214	(unsigned long )data =
	215	min_t(unsigned long, val, MAX_STACK_TRACE_DEPTH);
	216
	217	return 0;
	218	}
	219
	220	DEFINE_SIMPLE_ATTRIBUTE(fops_stacktrace_depth, debugfs_ul_get,
	221	debugfs_stacktrace_depth_set, "%llu\n");
	222
053cf510 GKH	223	static void debugfs_create_stacktrace_depth(const char *name, umode_t mode,
	224	struct dentry *parent,
	225	unsigned long *value)
a124c28e	226	{
053cf510	227	debugfs_create_file(name, mode, parent, value, &fops_stacktrace_depth);
a124c28e	228	}
8307fc25	229
6ddb23c7	230	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
a124c28e	231
dd48c085 AM	232	struct dentry fault_create_debugfs_attr(const char name,
dd48c085 AM	233	struct dentry parent, struct fault_attr attr)
6ff1cb35	234	{
f4ae40a6	235	umode_t mode = S_IFREG \| S_IRUSR \| S_IWUSR;
6ff1cb35 AM	236	struct dentry *dir;
6ff1cb35 AM	237
dd48c085	238	dir = debugfs_create_dir(name, parent);
053cf510 GKH	239	if (IS_ERR(dir))
	240	return dir;
	241
e9bc360b AM	242	prandom_init_once(&fault_rnd_state);
e9bc360b AM	243
053cf510 GKH	244	debugfs_create_ul("probability", mode, dir, &attr->probability);
	245	debugfs_create_ul("interval", mode, dir, &attr->interval);
	246	debugfs_create_atomic_t("times", mode, dir, &attr->times);
	247	debugfs_create_atomic_t("space", mode, dir, &attr->space);
	248	debugfs_create_ul("verbose", mode, dir, &attr->verbose);
	249	debugfs_create_u32("verbose_ratelimit_interval_ms", mode, dir,
	250	&attr->ratelimit_state.interval);
	251	debugfs_create_u32("verbose_ratelimit_burst", mode, dir,
	252	&attr->ratelimit_state.burst);
	253	debugfs_create_bool("task-filter", mode, dir, &attr->task_filter);
1df49008 AM	254
1df49008 AM	255	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
053cf510 GKH	256	debugfs_create_stacktrace_depth("stacktrace-depth", mode, dir,
053cf510 GKH	257	&attr->stacktrace_depth);
01999074 WY	258	debugfs_create_xul("require-start", mode, dir, &attr->require_start);
	259	debugfs_create_xul("require-end", mode, dir, &attr->require_end);
	260	debugfs_create_xul("reject-start", mode, dir, &attr->reject_start);
	261	debugfs_create_xul("reject-end", mode, dir, &attr->reject_end);
1df49008 AM	262	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
1df49008 AM	263
6adc4a22	264	attr->dname = dget(dir);
dd48c085	265	return dir;
6ff1cb35	266	}
df87ecbf	267	EXPORT_SYMBOL_GPL(fault_create_debugfs_attr);
6ff1cb35 AM	268
6ff1cb35 AM	269	#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
4668c7a2 AM	270
	271	#ifdef CONFIG_FAULT_INJECTION_CONFIGFS
	272
	273	/* These configfs attribute utilities are copied from drivers/block/null_blk/main.c */
	274
	275	static ssize_t fault_uint_attr_show(unsigned int val, char *page)
	276	{
	277	return snprintf(page, PAGE_SIZE, "%u\n", val);
	278	}
	279
	280	static ssize_t fault_ulong_attr_show(unsigned long val, char *page)
	281	{
	282	return snprintf(page, PAGE_SIZE, "%lu\n", val);
	283	}
	284
	285	static ssize_t fault_bool_attr_show(bool val, char *page)
	286	{
	287	return snprintf(page, PAGE_SIZE, "%u\n", val);
	288	}
	289
	290	static ssize_t fault_atomic_t_attr_show(atomic_t val, char *page)
	291	{
	292	return snprintf(page, PAGE_SIZE, "%d\n", atomic_read(&val));
	293	}
	294
	295	static ssize_t fault_uint_attr_store(unsigned int val, const char page, size_t count)
	296	{
	297	unsigned int tmp;
	298	int result;
	299
	300	result = kstrtouint(page, 0, &tmp);
	301	if (result < 0)
	302	return result;
	303
	304	*val = tmp;
	305	return count;
	306	}
	307
	308	static ssize_t fault_ulong_attr_store(unsigned long val, const char page, size_t count)
	309	{
	310	int result;
	311	unsigned long tmp;
	312
	313	result = kstrtoul(page, 0, &tmp);
	314	if (result < 0)
	315	return result;
	316
	317	*val = tmp;
	318	return count;
	319	}
	320
	321	static ssize_t fault_bool_attr_store(bool val, const char page, size_t count)
	322	{
	323	bool tmp;
	324	int result;
	325
	326	result = kstrtobool(page, &tmp);
	327	if (result < 0)
	328	return result;
	329
	330	*val = tmp;
	331	return count;
	332	}
	333
334	static ssize_t fault_atomic_t_attr_store(atomic_t val, const char page, size_t count)
335	{
336	int tmp;
337	int result;
338
339	result = kstrtoint(page, 0, &tmp);
340	if (result < 0)
341	return result;
342
343	atomic_set(val, tmp);
344	return count;
345	}
346
347	#define CONFIGFS_ATTR_NAMED(_pfx, _name, _attr_name) \
348	static struct configfs_attribute _pfx##attr_##_name = { \
349	.ca_name = _attr_name, \
350	.ca_mode = 0644, \
351	.ca_owner = THIS_MODULE, \
352	.show = _pfx##_name##_show, \
353	.store = _pfx##_name##_store, \
354	}
355
356	static struct fault_config to_fault_config(struct config_item item)
357	{
358	return container_of(to_config_group(item), struct fault_config, group);
359	}
360
361	#define FAULT_CONFIGFS_ATTR_NAMED(NAME, ATTR_NAME, MEMBER, TYPE) \
362	static ssize_t fault_##NAME##_show(struct config_item item, char page) \
363	{ \
364	return fault_##TYPE##_attr_show(to_fault_config(item)->attr.MEMBER, page); \
365	} \
366	static ssize_t fault_##NAME##_store(struct config_item item, const char page, size_t count) \
367	{ \
368	struct fault_config *config = to_fault_config(item); \
369	return fault_##TYPE##_attr_store(&config->attr.MEMBER, page, count); \
370	} \
371	CONFIGFS_ATTR_NAMED(fault_, NAME, ATTR_NAME)
372
373	#define FAULT_CONFIGFS_ATTR(NAME, TYPE) \
374	FAULT_CONFIGFS_ATTR_NAMED(NAME, __stringify(NAME), NAME, TYPE)
375
376	FAULT_CONFIGFS_ATTR(probability, ulong);
377	FAULT_CONFIGFS_ATTR(interval, ulong);
378	FAULT_CONFIGFS_ATTR(times, atomic_t);
379	FAULT_CONFIGFS_ATTR(space, atomic_t);
380	FAULT_CONFIGFS_ATTR(verbose, ulong);
381	FAULT_CONFIGFS_ATTR_NAMED(ratelimit_interval, "verbose_ratelimit_interval_ms",
382	ratelimit_state.interval, uint);
383	FAULT_CONFIGFS_ATTR_NAMED(ratelimit_burst, "verbose_ratelimit_burst",
384	ratelimit_state.burst, uint);
385	FAULT_CONFIGFS_ATTR_NAMED(task_filter, "task-filter", task_filter, bool);
386
387	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
388
389	static ssize_t fault_stacktrace_depth_show(struct config_item item, char page)
390	{
391	return fault_ulong_attr_show(to_fault_config(item)->attr.stacktrace_depth, page);
392	}
393
394	static ssize_t fault_stacktrace_depth_store(struct config_item item, const char page,
395	size_t count)
396	{
397	int result;
398	unsigned long tmp;
399
400	result = kstrtoul(page, 0, &tmp);
401	if (result < 0)
402	return result;
403
404	to_fault_config(item)->attr.stacktrace_depth =
405	min_t(unsigned long, tmp, MAX_STACK_TRACE_DEPTH);
406
407	return count;
408	}
409
410	CONFIGFS_ATTR_NAMED(fault_, stacktrace_depth, "stacktrace-depth");
411
412	static ssize_t fault_xul_attr_show(unsigned long val, char *page)
413	{
414	return snprintf(page, PAGE_SIZE,
415	sizeof(val) == sizeof(u32) ? "0x%08lx\n" : "0x%016lx\n", val);
416	}
417
418	static ssize_t fault_xul_attr_store(unsigned long val, const char page, size_t count)
419	{
420	return fault_ulong_attr_store(val, page, count);
421	}
422
423	FAULT_CONFIGFS_ATTR_NAMED(require_start, "require-start", require_start, xul);
424	FAULT_CONFIGFS_ATTR_NAMED(require_end, "require-end", require_end, xul);
425	FAULT_CONFIGFS_ATTR_NAMED(reject_start, "reject-start", reject_start, xul);
426	FAULT_CONFIGFS_ATTR_NAMED(reject_end, "reject-end", reject_end, xul);
427
428	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
429
430	static struct configfs_attribute *fault_config_attrs[] = {
431	&fault_attr_probability,
432	&fault_attr_interval,
433	&fault_attr_times,
434	&fault_attr_space,
435	&fault_attr_verbose,
436	&fault_attr_ratelimit_interval,
437	&fault_attr_ratelimit_burst,
438	&fault_attr_task_filter,
439	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
440	&fault_attr_stacktrace_depth,
441	&fault_attr_require_start,
442	&fault_attr_require_end,
443	&fault_attr_reject_start,
444	&fault_attr_reject_end,
445	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
446	NULL,
447	};
448
449	static const struct config_item_type fault_config_type = {
450	.ct_attrs = fault_config_attrs,
451	.ct_owner = THIS_MODULE,
452	};
453
454	void fault_config_init(struct fault_config config, const char name)
455	{
e9bc360b AM	456	prandom_init_once(&fault_rnd_state);
e9bc360b AM	457
4668c7a2 AM	458	config_group_init_type_name(&config->group, name, &fault_config_type);
	459	}
	460	EXPORT_SYMBOL_GPL(fault_config_init);
	461
	462	#endif /* CONFIG_FAULT_INJECTION_CONFIGFS */