Contributors: 15
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Akinobu Mita |
822 |
75.69% |
10 |
34.48% |
| Dmitriy Monakhov |
78 |
7.18% |
1 |
3.45% |
| Don Mullis |
70 |
6.45% |
3 |
10.34% |
| Dmitriy Vyukov |
23 |
2.12% |
2 |
6.90% |
| Greg Kroah-Hartman |
21 |
1.93% |
1 |
3.45% |
| Christoph Hellwig |
15 |
1.38% |
1 |
3.45% |
| Per Forlin |
15 |
1.38% |
2 |
6.90% |
| Anton Blanchard |
12 |
1.10% |
1 |
3.45% |
| Will Deacon |
8 |
0.74% |
1 |
3.45% |
| Thomas Gleixner |
7 |
0.64% |
2 |
6.90% |
| Stephen Rothwell |
6 |
0.55% |
1 |
3.45% |
| Al Viro |
3 |
0.28% |
1 |
3.45% |
| Alexey Dobriyan |
3 |
0.28% |
1 |
3.45% |
| Florian Westphal |
2 |
0.18% |
1 |
3.45% |
| Paul Gortmaker |
1 |
0.09% |
1 |
3.45% |
| Total |
1086 |
|
29 |
|
// SPDX-License-Identifier: GPL-2.0-only
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/random.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, ×) < 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)
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(struct fault_attr *attr, ssize_t size)
{
if (in_task()) {
unsigned int fail_nth = READ_ONCE(current->fail_nth);
if (fail_nth) {
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 (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 <= prandom_u32() % 100)
return false;
if (!fail_stacktrace(attr))
return false;
fail:
fail_dump(attr);
if (atomic_read(&attr->times) != -1)
atomic_dec_not_zero(&attr->times);
return true;
}
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_ul("require-start", mode, dir, &attr->require_start);
debugfs_create_ul("require-end", mode, dir, &attr->require_end);
debugfs_create_ul("reject-start", mode, dir, &attr->reject_start);
debugfs_create_ul("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 */