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(I'm so sorry!) Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
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/* * 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, ×) < 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 %s, 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 */
if (strscpy(attr->dname, name, sizeof(attr->dname)) == -E2BIG) pr_warn("FAULT_INJECTION: name '%s' truncated to '%s'\n", name, attr->dname); 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 */