diff options
Diffstat (limited to 'lib/fault-inject.c')
| -rw-r--r-- | lib/fault-inject.c | 220 |
1 files changed, 218 insertions, 2 deletions
diff --git a/lib/fault-inject.c b/lib/fault-inject.c index 6cff320c4eb4..999053fa133e 100644 --- a/lib/fault-inject.c +++ b/lib/fault-inject.c @@ -1,7 +1,8 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/kernel.h> #include <linux/init.h> -#include <linux/random.h> +#include <linux/prandom.h> +#include <linux/debugfs.h> #include <linux/sched.h> #include <linux/stat.h> #include <linux/types.h> @@ -12,6 +13,24 @@ #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. */ @@ -30,6 +49,8 @@ int setup_fault_attr(struct fault_attr *attr, char *str) return 0; } + prandom_init_once(&fault_rnd_state); + attr->probability = probability; attr->interval = interval; atomic_set(&attr->times, times); @@ -145,7 +166,7 @@ bool should_fail_ex(struct fault_attr *attr, ssize_t size, int flags) return false; } - if (attr->probability <= get_random_u32_below(100)) + if (attr->probability <= fault_prandom_u32_below_100()) return false; fail: @@ -218,6 +239,8 @@ struct dentry *fault_create_debugfs_attr(const char *name, 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); @@ -244,3 +267,196 @@ struct dentry *fault_create_debugfs_attr(const char *name, 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 */ |