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

// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/random.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>

/*
 * 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;
	}

	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 <= get_random_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;

	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)
{
	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>
	3	#include <linux/init.h>
	4	#include <linux/random.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>
	14
	15	/*
	16	* setup_fault_attr() is a helper function for various __setup handlers, so it
	17	* returns 0 on error, because that is what __setup handlers do.
	18	*/
6cba00ea	19	int setup_fault_attr(struct fault_attr attr, char str)
6ff1cb35 AM	20	{
	21	unsigned long probability;
	22	unsigned long interval;
	23	int times;
	24	int space;
	25
	26	/* "<interval>,<probability>,<space>,<times>" */
	27	if (sscanf(str, "%lu,%lu,%d,%d",
	28	&interval, &probability, &space, &times) < 4) {
	29	printk(KERN_WARNING
	30	"FAULT_INJECTION: failed to parse arguments\n");
	31	return 0;
	32	}
	33
	34	attr->probability = probability;
	35	attr->interval = interval;
	36	atomic_set(&attr->times, times);
	37	atomic_set(&attr->space, space);
	38
	39	return 1;
	40	}
6cba00ea	41	EXPORT_SYMBOL_GPL(setup_fault_attr);
6ff1cb35 AM	42
	43	static void fail_dump(struct fault_attr *attr)
	44	{
6adc4a22 DM	45	if (attr->verbose > 0 && __ratelimit(&attr->ratelimit_state)) {
	46	printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure.\n"
	47	"name %pd, interval %lu, probability %lu, "
	48	"space %d, times %d\n", attr->dname,
bb387002	49	attr->interval, attr->probability,
6adc4a22 DM	50	atomic_read(&attr->space),
	51	atomic_read(&attr->times));
	52	if (attr->verbose > 1)
	53	dump_stack();
	54	}
6ff1cb35 AM	55	}
	56
	57	#define atomic_dec_not_zero(v) atomic_add_unless((v), -1, 0)
	58
08b3df2d	59	static bool fail_task(struct fault_attr attr, struct task_struct task)
f4f154fd	60	{
f2ad37da	61	return in_task() && task->make_it_fail;
f4f154fd AM	62	}
f4f154fd AM	63
a124c28e DM	64	#define MAX_STACK_TRACE_DEPTH 32
a124c28e DM	65
1df49008	66	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
329409ae	67
08b3df2d	68	static bool fail_stacktrace(struct fault_attr *attr)
329409ae	69	{
329409ae AM	70	int depth = attr->stacktrace_depth;
329409ae AM	71	unsigned long entries[MAX_STACK_TRACE_DEPTH];
30191250	72	int n, nr_entries;
329409ae AM	73	bool found = (attr->require_start == 0 && attr->require_end == ULONG_MAX);
329409ae AM	74
4acb9e51	75	if (depth == 0 \|\| (found && !attr->reject_start && !attr->reject_end))
329409ae AM	76	return found;
329409ae AM	77
30191250 TG	78	nr_entries = stack_trace_save(entries, depth, 1);
30191250 TG	79	for (n = 0; n < nr_entries; n++) {
329409ae AM	80	if (attr->reject_start <= entries[n] &&
329409ae AM	81	entries[n] < attr->reject_end)
08b3df2d	82	return false;
329409ae AM	83	if (attr->require_start <= entries[n] &&
329409ae AM	84	entries[n] < attr->require_end)
08b3df2d	85	found = true;
329409ae AM	86	}
	87	return found;
	88	}
	89
	90	#else
	91
08b3df2d	92	static inline bool fail_stacktrace(struct fault_attr *attr)
329409ae	93	{
1df49008	94	return true;
329409ae AM	95	}
329409ae AM	96
1df49008	97	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
329409ae	98
6ff1cb35 AM	99	/*
	100	* This code is stolen from failmalloc-1.0
	101	* http://www.nongnu.org/failmalloc/
	102	*/
	103
ea4452de	104	bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags)
6ff1cb35	105	{
f9eeef59 WY	106	bool stack_checked = false;
f9eeef59 WY	107
1203c8e6 AM	108	if (in_task()) {
	109	unsigned int fail_nth = READ_ONCE(current->fail_nth);
	110
9eeb52ae	111	if (fail_nth) {
f9eeef59 WY	112	if (!fail_stacktrace(attr))
	113	return false;
	114
	115	stack_checked = true;
9b4fb5ce WD	116	fail_nth--;
	117	WRITE_ONCE(current->fail_nth, fail_nth);
	118	if (!fail_nth)
9eeb52ae	119	goto fail;
1203c8e6	120
9eeb52ae AM	121	return false;
9eeb52ae AM	122	}
e41d5818 DV	123	}
e41d5818 DV	124
f39cdaeb AB	125	/* No need to check any other properties if the probability is 0 */
	126	if (attr->probability == 0)
	127	return false;
	128
f4f154fd	129	if (attr->task_filter && !fail_task(attr, current))
08b3df2d	130	return false;
f4f154fd	131
6ff1cb35	132	if (atomic_read(&attr->times) == 0)
08b3df2d	133	return false;
6ff1cb35	134
f9eeef59 WY	135	if (!stack_checked && !fail_stacktrace(attr))
	136	return false;
	137
6ff1cb35 AM	138	if (atomic_read(&attr->space) > size) {
6ff1cb35 AM	139	atomic_sub(size, &attr->space);
08b3df2d	140	return false;
6ff1cb35 AM	141	}
	142
	143	if (attr->interval > 1) {
	144	attr->count++;
	145	if (attr->count % attr->interval)
08b3df2d	146	return false;
6ff1cb35 AM	147	}
6ff1cb35 AM	148
8032bf12	149	if (attr->probability <= get_random_u32_below(100))
f1729c28	150	return false;
6ff1cb35	151
e41d5818	152	fail:
ea4452de QZ	153	if (!(flags & FAULT_NOWARN))
ea4452de QZ	154	fail_dump(attr);
6ff1cb35 AM	155
	156	if (atomic_read(&attr->times) != -1)
	157	atomic_dec_not_zero(&attr->times);
	158
08b3df2d	159	return true;
6ff1cb35	160	}
ea4452de QZ	161
	162	bool should_fail(struct fault_attr *attr, ssize_t size)
	163	{
	164	return should_fail_ex(attr, size, 0);
	165	}
df87ecbf	166	EXPORT_SYMBOL_GPL(should_fail);
6ff1cb35 AM	167
	168	#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
	169
8b88b099	170	static int debugfs_ul_set(void *data, u64 val)
6ff1cb35 AM	171	{
6ff1cb35 AM	172	(unsigned long )data = val;
8b88b099	173	return 0;
6ff1cb35 AM	174	}
6ff1cb35 AM	175
8b88b099	176	static int debugfs_ul_get(void data, u64 val)
6ff1cb35	177	{
8b88b099 CH	178	val = (unsigned long *)data;
8b88b099 CH	179	return 0;
6ff1cb35 AM	180	}
	181
	182	DEFINE_SIMPLE_ATTRIBUTE(fops_ul, debugfs_ul_get, debugfs_ul_set, "%llu\n");
	183
053cf510 GKH	184	static void debugfs_create_ul(const char *name, umode_t mode,
053cf510 GKH	185	struct dentry parent, unsigned long value)
6ff1cb35	186	{
053cf510	187	debugfs_create_file(name, mode, parent, value, &fops_ul);
6ff1cb35 AM	188	}
6ff1cb35 AM	189
6ddb23c7	190	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
a124c28e	191
8307fc25 AM	192	static int debugfs_stacktrace_depth_set(void *data, u64 val)
	193	{
	194	(unsigned long )data =
	195	min_t(unsigned long, val, MAX_STACK_TRACE_DEPTH);
	196
	197	return 0;
	198	}
	199
	200	DEFINE_SIMPLE_ATTRIBUTE(fops_stacktrace_depth, debugfs_ul_get,
	201	debugfs_stacktrace_depth_set, "%llu\n");
	202
053cf510 GKH	203	static void debugfs_create_stacktrace_depth(const char *name, umode_t mode,
	204	struct dentry *parent,
	205	unsigned long *value)
a124c28e	206	{
053cf510	207	debugfs_create_file(name, mode, parent, value, &fops_stacktrace_depth);
a124c28e	208	}
8307fc25	209
6ddb23c7	210	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
a124c28e	211
dd48c085 AM	212	struct dentry fault_create_debugfs_attr(const char name,
dd48c085 AM	213	struct dentry parent, struct fault_attr attr)
6ff1cb35	214	{
f4ae40a6	215	umode_t mode = S_IFREG \| S_IRUSR \| S_IWUSR;
6ff1cb35 AM	216	struct dentry *dir;
6ff1cb35 AM	217
dd48c085	218	dir = debugfs_create_dir(name, parent);
053cf510 GKH	219	if (IS_ERR(dir))
	220	return dir;
	221
	222	debugfs_create_ul("probability", mode, dir, &attr->probability);
	223	debugfs_create_ul("interval", mode, dir, &attr->interval);
	224	debugfs_create_atomic_t("times", mode, dir, &attr->times);
	225	debugfs_create_atomic_t("space", mode, dir, &attr->space);
	226	debugfs_create_ul("verbose", mode, dir, &attr->verbose);
	227	debugfs_create_u32("verbose_ratelimit_interval_ms", mode, dir,
	228	&attr->ratelimit_state.interval);
	229	debugfs_create_u32("verbose_ratelimit_burst", mode, dir,
	230	&attr->ratelimit_state.burst);
	231	debugfs_create_bool("task-filter", mode, dir, &attr->task_filter);
1df49008 AM	232
1df49008 AM	233	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
053cf510 GKH	234	debugfs_create_stacktrace_depth("stacktrace-depth", mode, dir,
053cf510 GKH	235	&attr->stacktrace_depth);
01999074 WY	236	debugfs_create_xul("require-start", mode, dir, &attr->require_start);
	237	debugfs_create_xul("require-end", mode, dir, &attr->require_end);
	238	debugfs_create_xul("reject-start", mode, dir, &attr->reject_start);
	239	debugfs_create_xul("reject-end", mode, dir, &attr->reject_end);
1df49008 AM	240	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
1df49008 AM	241
6adc4a22	242	attr->dname = dget(dir);
dd48c085	243	return dir;
6ff1cb35	244	}
df87ecbf	245	EXPORT_SYMBOL_GPL(fault_create_debugfs_attr);
6ff1cb35 AM	246
6ff1cb35 AM	247	#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
4668c7a2 AM	248
	249	#ifdef CONFIG_FAULT_INJECTION_CONFIGFS
	250
	251	/* These configfs attribute utilities are copied from drivers/block/null_blk/main.c */
	252
	253	static ssize_t fault_uint_attr_show(unsigned int val, char *page)
	254	{
	255	return snprintf(page, PAGE_SIZE, "%u\n", val);
	256	}
	257
	258	static ssize_t fault_ulong_attr_show(unsigned long val, char *page)
	259	{
	260	return snprintf(page, PAGE_SIZE, "%lu\n", val);
	261	}
	262
	263	static ssize_t fault_bool_attr_show(bool val, char *page)
	264	{
	265	return snprintf(page, PAGE_SIZE, "%u\n", val);
	266	}
	267
	268	static ssize_t fault_atomic_t_attr_show(atomic_t val, char *page)
	269	{
	270	return snprintf(page, PAGE_SIZE, "%d\n", atomic_read(&val));
	271	}
	272
	273	static ssize_t fault_uint_attr_store(unsigned int val, const char page, size_t count)
	274	{
	275	unsigned int tmp;
	276	int result;
	277
	278	result = kstrtouint(page, 0, &tmp);
	279	if (result < 0)
	280	return result;
	281
	282	*val = tmp;
	283	return count;
	284	}
	285
	286	static ssize_t fault_ulong_attr_store(unsigned long val, const char page, size_t count)
	287	{
	288	int result;
	289	unsigned long tmp;
	290
	291	result = kstrtoul(page, 0, &tmp);
	292	if (result < 0)
	293	return result;
	294
	295	*val = tmp;
	296	return count;
	297	}
	298
	299	static ssize_t fault_bool_attr_store(bool val, const char page, size_t count)
	300	{
	301	bool tmp;
	302	int result;
	303
	304	result = kstrtobool(page, &tmp);
	305	if (result < 0)
	306	return result;
	307
	308	*val = tmp;
	309	return count;
	310	}
	311
312	static ssize_t fault_atomic_t_attr_store(atomic_t val, const char page, size_t count)
313	{
314	int tmp;
315	int result;
316
317	result = kstrtoint(page, 0, &tmp);
318	if (result < 0)
319	return result;
320
321	atomic_set(val, tmp);
322	return count;
323	}
324
325	#define CONFIGFS_ATTR_NAMED(_pfx, _name, _attr_name) \
326	static struct configfs_attribute _pfx##attr_##_name = { \
327	.ca_name = _attr_name, \
328	.ca_mode = 0644, \
329	.ca_owner = THIS_MODULE, \
330	.show = _pfx##_name##_show, \
331	.store = _pfx##_name##_store, \
332	}
333
334	static struct fault_config to_fault_config(struct config_item item)
335	{
336	return container_of(to_config_group(item), struct fault_config, group);
337	}
338
339	#define FAULT_CONFIGFS_ATTR_NAMED(NAME, ATTR_NAME, MEMBER, TYPE) \
340	static ssize_t fault_##NAME##_show(struct config_item item, char page) \
341	{ \
342	return fault_##TYPE##_attr_show(to_fault_config(item)->attr.MEMBER, page); \
343	} \
344	static ssize_t fault_##NAME##_store(struct config_item item, const char page, size_t count) \
345	{ \
346	struct fault_config *config = to_fault_config(item); \
347	return fault_##TYPE##_attr_store(&config->attr.MEMBER, page, count); \
348	} \
349	CONFIGFS_ATTR_NAMED(fault_, NAME, ATTR_NAME)
350
351	#define FAULT_CONFIGFS_ATTR(NAME, TYPE) \
352	FAULT_CONFIGFS_ATTR_NAMED(NAME, __stringify(NAME), NAME, TYPE)
353
354	FAULT_CONFIGFS_ATTR(probability, ulong);
355	FAULT_CONFIGFS_ATTR(interval, ulong);
356	FAULT_CONFIGFS_ATTR(times, atomic_t);
357	FAULT_CONFIGFS_ATTR(space, atomic_t);
358	FAULT_CONFIGFS_ATTR(verbose, ulong);
359	FAULT_CONFIGFS_ATTR_NAMED(ratelimit_interval, "verbose_ratelimit_interval_ms",
360	ratelimit_state.interval, uint);
361	FAULT_CONFIGFS_ATTR_NAMED(ratelimit_burst, "verbose_ratelimit_burst",
362	ratelimit_state.burst, uint);
363	FAULT_CONFIGFS_ATTR_NAMED(task_filter, "task-filter", task_filter, bool);
364
365	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
366
367	static ssize_t fault_stacktrace_depth_show(struct config_item item, char page)
368	{
369	return fault_ulong_attr_show(to_fault_config(item)->attr.stacktrace_depth, page);
370	}
371
372	static ssize_t fault_stacktrace_depth_store(struct config_item item, const char page,
373	size_t count)
374	{
375	int result;
376	unsigned long tmp;
377
378	result = kstrtoul(page, 0, &tmp);
379	if (result < 0)
380	return result;
381
382	to_fault_config(item)->attr.stacktrace_depth =
383	min_t(unsigned long, tmp, MAX_STACK_TRACE_DEPTH);
384
385	return count;
386	}
387
388	CONFIGFS_ATTR_NAMED(fault_, stacktrace_depth, "stacktrace-depth");
389
390	static ssize_t fault_xul_attr_show(unsigned long val, char *page)
391	{
392	return snprintf(page, PAGE_SIZE,
393	sizeof(val) == sizeof(u32) ? "0x%08lx\n" : "0x%016lx\n", val);
394	}
395
396	static ssize_t fault_xul_attr_store(unsigned long val, const char page, size_t count)
397	{
398	return fault_ulong_attr_store(val, page, count);
399	}
400
401	FAULT_CONFIGFS_ATTR_NAMED(require_start, "require-start", require_start, xul);
402	FAULT_CONFIGFS_ATTR_NAMED(require_end, "require-end", require_end, xul);
403	FAULT_CONFIGFS_ATTR_NAMED(reject_start, "reject-start", reject_start, xul);
404	FAULT_CONFIGFS_ATTR_NAMED(reject_end, "reject-end", reject_end, xul);
405
406	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
407
408	static struct configfs_attribute *fault_config_attrs[] = {
409	&fault_attr_probability,
410	&fault_attr_interval,
411	&fault_attr_times,
412	&fault_attr_space,
413	&fault_attr_verbose,
414	&fault_attr_ratelimit_interval,
415	&fault_attr_ratelimit_burst,
416	&fault_attr_task_filter,
417	#ifdef CONFIG_FAULT_INJECTION_STACKTRACE_FILTER
418	&fault_attr_stacktrace_depth,
419	&fault_attr_require_start,
420	&fault_attr_require_end,
421	&fault_attr_reject_start,
422	&fault_attr_reject_end,
423	#endif /* CONFIG_FAULT_INJECTION_STACKTRACE_FILTER */
424	NULL,
425	};
426
427	static const struct config_item_type fault_config_type = {
428	.ct_attrs = fault_config_attrs,
429	.ct_owner = THIS_MODULE,
430	};
431
432	void fault_config_init(struct fault_config config, const char name)
433	{
434	config_group_init_type_name(&config->group, name, &fault_config_type);
435	}
436	EXPORT_SYMBOL_GPL(fault_config_init);
437
438	#endif /* CONFIG_FAULT_INJECTION_CONFIGFS */