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error-injection: Separate error-injection from kprobe

Browse source 
Since error-injection framework is not limited to be used
by kprobes, nor bpf. Other kernel subsystems can use it
freely for checking safeness of error-injection, e.g.
livepatch, ftrace etc.
So this separate error-injection framework from kprobes.

Some differences has been made:

- "kprobe" word is removed from any APIs/structures.
- BPF_ALLOW_ERROR_INJECTION() is renamed to
  ALLOW_ERROR_INJECTION() since it is not limited for BPF too.
- CONFIG_FUNCTION_ERROR_INJECTION is the config item of this
  feature. It is automatically enabled if the arch supports
  error injection feature for kprobe or ftrace etc.

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
Masami Hiramatsu 2018-01-13 02:55:03 +09:00 committed by Alexei Starovoitov
parent 66665ad2f1
commit 540adea380
22 changed files with 317 additions and 213 deletions
repo.diff.show_diff_stats Download patch file Download diff file Expand all files Collapse all files

2
arch/Kconfig
View file

@ -196,7 +196,7 @@ config HAVE_OPTPROBES
config HAVE_KPROBES_ON_FTRACE
bool
config HAVE_KPROBE_OVERRIDE
config HAVE_FUNCTION_ERROR_INJECTION
bool
config HAVE_NMI

2
arch/x86/Kconfig
View file

@ -154,7 +154,7 @@ config X86
select HAVE_KERNEL_XZ
select HAVE_KPROBES
select HAVE_KPROBES_ON_FTRACE
select HAVE_KPROBE_OVERRIDE
select HAVE_FUNCTION_ERROR_INJECTION
select HAVE_KRETPROBES
select HAVE_KVM
select HAVE_LIVEPATCH if X86_64

13
arch/x86/include/asm/error-injection.h Normal file
View file

@ -0,0 +1,13 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_ERROR_INJECTION_H
#define _ASM_ERROR_INJECTION_H
#include <linux/compiler.h>
#include <linux/linkage.h>
#include <asm/ptrace.h>
#include <asm-generic/error-injection.h>
asmlinkage void just_return_func(void);
void override_function_with_return(struct pt_regs *regs);
#endif /* _ASM_ERROR_INJECTION_H */

14
arch/x86/kernel/kprobes/core.c
View file

@ -1183,17 +1183,3 @@ int arch_trampoline_kprobe(struct kprobe *p)
{
return 0;
}
asmlinkage void override_func(void);
asm(
".type override_func, @function\n"
"override_func:\n"
" ret\n"
".size override_func, .-override_func\n"
);
void arch_kprobe_override_function(struct pt_regs *regs)
{
regs->ip = (unsigned long)&override_func;
}
NOKPROBE_SYMBOL(arch_kprobe_override_function);

1
arch/x86/lib/Makefile
View file

@ -26,6 +26,7 @@ lib-y += memcpy_$(BITS).o
lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o
lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o
lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o
lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
obj-y += msr.o msr-reg.o msr-reg-export.o hweight.o

19
arch/x86/lib/error-inject.c Normal file
View file

@ -0,0 +1,19 @@
// SPDX-License-Identifier: GPL-2.0
#include <linux/error-injection.h>
#include <linux/kprobes.h>
asmlinkage void just_return_func(void);
asm(
".type just_return_func, @function\n"
"just_return_func:\n"
" ret\n"
".size just_return_func, .-just_return_func\n"
);
void override_function_with_return(struct pt_regs *regs)
{
regs->ip = (unsigned long)&just_return_func;
}
NOKPROBE_SYMBOL(override_function_with_return);

4
fs/btrfs/disk-io.c
View file

@ -30,7 +30,7 @@
#include <linux/ratelimit.h>
#include <linux/uuid.h>
#include <linux/semaphore.h>
#include <linux/bpf.h>
#include <linux/error-injection.h>
#include <asm/unaligned.h>
#include "ctree.h"
#include "disk-io.h"
@ -3124,7 +3124,7 @@ int open_ctree(struct super_block *sb,
goto fail_block_groups;
goto retry_root_backup;
}
BPF_ALLOW_ERROR_INJECTION(open_ctree);
ALLOW_ERROR_INJECTION(open_ctree);
static void btrfs_end_buffer_write_sync(struct buffer_head *bh, int uptodate)
{

4
fs/btrfs/free-space-cache.c
View file

@ -22,7 +22,7 @@
#include <linux/slab.h>
#include <linux/math64.h>
#include <linux/ratelimit.h>
#include <linux/bpf.h>
#include <linux/error-injection.h>
#include "ctree.h"
#include "free-space-cache.h"
#include "transaction.h"
@ -333,7 +333,7 @@ static int io_ctl_init(struct btrfs_io_ctl *io_ctl, struct inode *inode,
return 0;
}
BPF_ALLOW_ERROR_INJECTION(io_ctl_init);
ALLOW_ERROR_INJECTION(io_ctl_init);
static void io_ctl_free(struct btrfs_io_ctl *io_ctl)
{

20
include/asm-generic/error-injection.h Normal file
View file

@ -0,0 +1,20 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_GENERIC_ERROR_INJECTION_H
#define _ASM_GENERIC_ERROR_INJECTION_H
#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
/*
* Whitelist ganerating macro. Specify functions which can be
* error-injectable using this macro.
*/
#define ALLOW_ERROR_INJECTION(fname) \
static unsigned long __used \
__attribute__((__section__("_error_injection_whitelist"))) \
_eil_addr_##fname = (unsigned long)fname;
#else
#define ALLOW_ERROR_INJECTION(fname)
#endif
#endif
#endif /* _ASM_GENERIC_ERROR_INJECTION_H */

14
include/asm-generic/vmlinux.lds.h
View file

@ -136,13 +136,13 @@
#define KPROBE_BLACKLIST()
#endif
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
#define ERROR_INJECT_LIST() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_kprobe_error_inject_list) = .; \
KEEP(*(_kprobe_error_inject_list)) \
VMLINUX_SYMBOL(__stop_kprobe_error_inject_list) = .;
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
#define ERROR_INJECT_WHITELIST() . = ALIGN(8); \
VMLINUX_SYMBOL(__start_error_injection_whitelist) = .;\
KEEP(*(_error_injection_whitelist)) \
VMLINUX_SYMBOL(__stop_error_injection_whitelist) = .;
#else
#define ERROR_INJECT_LIST()
#define ERROR_INJECT_WHITELIST()
#endif
#ifdef CONFIG_EVENT_TRACING
@ -573,7 +573,7 @@
FTRACE_EVENTS() \
TRACE_SYSCALLS() \
KPROBE_BLACKLIST() \
ERROR_INJECT_LIST() \
ERROR_INJECT_WHITELIST() \
MEM_DISCARD(init.rodata) \
CLK_OF_TABLES() \
RESERVEDMEM_OF_TABLES() \

11
include/linux/bpf.h
View file

@ -613,15 +613,4 @@ extern const struct bpf_func_proto bpf_sock_map_update_proto;
void bpf_user_rnd_init_once(void);
u64 bpf_user_rnd_u32(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5);
#if defined(__KERNEL__) && !defined(__ASSEMBLY__)
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
#define BPF_ALLOW_ERROR_INJECTION(fname) \
static unsigned long __used \
__attribute__((__section__("_kprobe_error_inject_list"))) \
_eil_addr_##fname = (unsigned long)fname;
#else
#define BPF_ALLOW_ERROR_INJECTION(fname)
#endif
#endif
#endif /* _LINUX_BPF_H */

21
include/linux/error-injection.h Normal file
View file

@ -0,0 +1,21 @@
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_ERROR_INJECTION_H
#define _LINUX_ERROR_INJECTION_H
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
#include <asm/error-injection.h>
extern bool within_error_injection_list(unsigned long addr);
#else /* !CONFIG_FUNCTION_ERROR_INJECTION */
#include <asm-generic/error-injection.h>
static inline bool within_error_injection_list(unsigned long addr)
{
return false;
}
#endif
#endif /* _LINUX_ERROR_INJECTION_H */

1
include/linux/kprobes.h
View file

@ -271,7 +271,6 @@ extern bool arch_kprobe_on_func_entry(unsigned long offset);
extern bool kprobe_on_func_entry(kprobe_opcode_t *addr, const char *sym, unsigned long offset);
extern bool within_kprobe_blacklist(unsigned long addr);
extern bool within_kprobe_error_injection_list(unsigned long addr);
struct kprobe_insn_cache {
struct mutex mutex;

6
include/linux/module.h
View file

@ -476,9 +476,9 @@ struct module {
unsigned int num_ctors;
#endif
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
unsigned int num_kprobe_ei_funcs;
unsigned long *kprobe_ei_funcs;
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
unsigned int num_ei_funcs;
unsigned long *ei_funcs;
#endif
} ____cacheline_aligned __randomize_layout;
#ifndef MODULE_ARCH_INIT

163
kernel/kprobes.c
View file

@ -83,16 +83,6 @@ static raw_spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
return &(kretprobe_table_locks[hash].lock);
}
/* List of symbols that can be overriden for error injection. */
static LIST_HEAD(kprobe_error_injection_list);
static DEFINE_MUTEX(kprobe_ei_mutex);
struct kprobe_ei_entry {
struct list_head list;
unsigned long start_addr;
unsigned long end_addr;
void *priv;
};
/* Blacklist -- list of struct kprobe_blacklist_entry */
static LIST_HEAD(kprobe_blacklist);
@ -1404,17 +1394,6 @@ bool within_kprobe_blacklist(unsigned long addr)
return false;
}
bool within_kprobe_error_injection_list(unsigned long addr)
{
struct kprobe_ei_entry *ent;
list_for_each_entry(ent, &kprobe_error_injection_list, list) {
if (addr >= ent->start_addr && addr < ent->end_addr)
return true;
}
return false;
}
/*
* If we have a symbol_name argument, look it up and add the offset field
* to it. This way, we can specify a relative address to a symbol.
@ -2189,86 +2168,6 @@ static int __init populate_kprobe_blacklist(unsigned long *start,
return 0;
}
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
/* Markers of the _kprobe_error_inject_list section */
extern unsigned long __start_kprobe_error_inject_list[];
extern unsigned long __stop_kprobe_error_inject_list[];
/*
* Lookup and populate the kprobe_error_injection_list.
*
* For safety reasons we only allow certain functions to be overriden with
* bpf_error_injection, so we need to populate the list of the symbols that have
* been marked as safe for overriding.
*/
static void populate_kprobe_error_injection_list(unsigned long *start,
unsigned long *end,
void *priv)
{
unsigned long *iter;
struct kprobe_ei_entry *ent;
unsigned long entry, offset = 0, size = 0;
mutex_lock(&kprobe_ei_mutex);
for (iter = start; iter < end; iter++) {
entry = arch_deref_entry_point((void *)*iter);
if (!kernel_text_address(entry) ||
!kallsyms_lookup_size_offset(entry, &size, &offset)) {
pr_err("Failed to find error inject entry at %p\n",
(void *)entry);
continue;
}
ent = kmalloc(sizeof(*ent), GFP_KERNEL);
if (!ent)
break;
ent->start_addr = entry;
ent->end_addr = entry + size;
ent->priv = priv;
INIT_LIST_HEAD(&ent->list);
list_add_tail(&ent->list, &kprobe_error_injection_list);
}
mutex_unlock(&kprobe_ei_mutex);
}
static void __init populate_kernel_kprobe_ei_list(void)
{
populate_kprobe_error_injection_list(__start_kprobe_error_inject_list,
__stop_kprobe_error_inject_list,
NULL);
}
static void module_load_kprobe_ei_list(struct module *mod)
{
if (!mod->num_kprobe_ei_funcs)
return;
populate_kprobe_error_injection_list(mod->kprobe_ei_funcs,
mod->kprobe_ei_funcs +
mod->num_kprobe_ei_funcs, mod);
}
static void module_unload_kprobe_ei_list(struct module *mod)
{
struct kprobe_ei_entry *ent, *n;
if (!mod->num_kprobe_ei_funcs)
return;
mutex_lock(&kprobe_ei_mutex);
list_for_each_entry_safe(ent, n, &kprobe_error_injection_list, list) {
if (ent->priv == mod) {
list_del_init(&ent->list);
kfree(ent);
}
}
mutex_unlock(&kprobe_ei_mutex);
}
#else
static inline void __init populate_kernel_kprobe_ei_list(void) {}
static inline void module_load_kprobe_ei_list(struct module *m) {}
static inline void module_unload_kprobe_ei_list(struct module *m) {}
#endif
/* Module notifier call back, checking kprobes on the module */
static int kprobes_module_callback(struct notifier_block *nb,
unsigned long val, void *data)
@ -2279,11 +2178,6 @@ static int kprobes_module_callback(struct notifier_block *nb,
unsigned int i;
int checkcore = (val == MODULE_STATE_GOING);
if (val == MODULE_STATE_COMING)
module_load_kprobe_ei_list(mod);
else if (val == MODULE_STATE_GOING)
module_unload_kprobe_ei_list(mod);
if (val != MODULE_STATE_GOING && val != MODULE_STATE_LIVE)
return NOTIFY_DONE;
@ -2346,8 +2240,6 @@ static int __init init_kprobes(void)
pr_err("Please take care of using kprobes.\n");
}
populate_kernel_kprobe_ei_list();
if (kretprobe_blacklist_size) {
/* lookup the function address from its name */
for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
@ -2515,56 +2407,6 @@ static const struct file_operations debugfs_kprobe_blacklist_ops = {
.release = seq_release,
};
/*
* kprobes/error_injection_list -- shows which functions can be overriden for
* error injection.
* */
static void *kprobe_ei_seq_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&kprobe_ei_mutex);
return seq_list_start(&kprobe_error_injection_list, *pos);
}
static void kprobe_ei_seq_stop(struct seq_file *m, void *v)
{
mutex_unlock(&kprobe_ei_mutex);
}
static void *kprobe_ei_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &kprobe_error_injection_list, pos);
}
static int kprobe_ei_seq_show(struct seq_file *m, void *v)
{
char buffer[KSYM_SYMBOL_LEN];
struct kprobe_ei_entry *ent =
list_entry(v, struct kprobe_ei_entry, list);
sprint_symbol(buffer, ent->start_addr);
seq_printf(m, "%s\n", buffer);
return 0;
}
static const struct seq_operations kprobe_ei_seq_ops = {
.start = kprobe_ei_seq_start,
.next = kprobe_ei_seq_next,
.stop = kprobe_ei_seq_stop,
.show = kprobe_ei_seq_show,
};
static int kprobe_ei_open(struct inode *inode, struct file *filp)
{
return seq_open(filp, &kprobe_ei_seq_ops);
}
static const struct file_operations debugfs_kprobe_ei_ops = {
.open = kprobe_ei_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static void arm_all_kprobes(void)
{
struct hlist_head *head;
@ -2706,11 +2548,6 @@ static int __init debugfs_kprobe_init(void)
if (!file)
goto error;
file = debugfs_create_file("error_injection_list", 0444, dir, NULL,
&debugfs_kprobe_ei_ops);
if (!file)
goto error;
return 0;
error:

8
kernel/module.c
View file

@ -3118,10 +3118,10 @@ static int find_module_sections(struct module *mod, struct load_info *info)
sizeof(*mod->ftrace_callsites),
&mod->num_ftrace_callsites);
#endif
#ifdef CONFIG_BPF_KPROBE_OVERRIDE
mod->kprobe_ei_funcs = section_objs(info, "_kprobe_error_inject_list",
sizeof(*mod->kprobe_ei_funcs),
&mod->num_kprobe_ei_funcs);
#ifdef CONFIG_FUNCTION_ERROR_INJECTION
mod->ei_funcs = section_objs(info, "_error_injection_whitelist",
sizeof(*mod->ei_funcs),
&mod->num_ei_funcs);
#endif
mod->extable = section_objs(info, "__ex_table",
sizeof(*mod->extable), &mod->num_exentries);

2
kernel/trace/Kconfig
View file

@ -533,7 +533,7 @@ config FUNCTION_PROFILER
config BPF_KPROBE_OVERRIDE
bool "Enable BPF programs to override a kprobed function"
depends on BPF_EVENTS
depends on HAVE_KPROBE_OVERRIDE
depends on FUNCTION_ERROR_INJECTION
default n
help
Allows BPF to override the execution of a probed function and

4
kernel/trace/bpf_trace.c
View file

@ -14,7 +14,7 @@
#include <linux/uaccess.h>
#include <linux/ctype.h>
#include <linux/kprobes.h>
#include <asm/kprobes.h>
#include <linux/error-injection.h>
#include "trace_probe.h"
#include "trace.h"
@ -84,7 +84,7 @@ EXPORT_SYMBOL_GPL(trace_call_bpf);
BPF_CALL_2(bpf_override_return, struct pt_regs *, regs, unsigned long, rc)
{
regs_set_return_value(regs, rc);
arch_kprobe_override_function(regs);
override_function_with_return(regs);
return 0;
}

3
kernel/trace/trace_kprobe.c
View file

@ -21,6 +21,7 @@
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/rculist.h>
#include <linux/error-injection.h>
#include "trace_probe.h"
@ -107,7 +108,7 @@ bool trace_kprobe_error_injectable(struct trace_event_call *call)
} else {
addr = (unsigned long)tk->rp.kp.addr;
}
return within_kprobe_error_injection_list(addr);
return within_error_injection_list(addr);
}
static int register_kprobe_event(struct trace_kprobe *tk);

4
lib/Kconfig.debug
View file

@ -1500,6 +1500,10 @@ config FAULT_INJECTION
Provide fault-injection framework.
For more details, see Documentation/fault-injection/.
config FUNCTION_ERROR_INJECTION
def_bool y
depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
config FAILSLAB
bool "Fault-injection capability for kmalloc"
depends on FAULT_INJECTION

1
lib/Makefile
View file

@ -149,6 +149,7 @@ obj-$(CONFIG_NETDEV_NOTIFIER_ERROR_INJECT) += netdev-notifier-error-inject.o
obj-$(CONFIG_MEMORY_NOTIFIER_ERROR_INJECT) += memory-notifier-error-inject.o
obj-$(CONFIG_OF_RECONFIG_NOTIFIER_ERROR_INJECT) += \
of-reconfig-notifier-error-inject.o
obj-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o
lib-$(CONFIG_GENERIC_BUG) += bug.o

213
lib/error-inject.c Normal file
View file

@ -0,0 +1,213 @@
// SPDX-License-Identifier: GPL-2.0
// error-inject.c: Function-level error injection table
#include <linux/error-injection.h>
#include <linux/debugfs.h>
#include <linux/kallsyms.h>
#include <linux/kprobes.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/list.h>
#include <linux/slab.h>
/* Whitelist of symbols that can be overridden for error injection. */
static LIST_HEAD(error_injection_list);
static DEFINE_MUTEX(ei_mutex);
struct ei_entry {
struct list_head list;
unsigned long start_addr;
unsigned long end_addr;
void *priv;
};
bool within_error_injection_list(unsigned long addr)
{
struct ei_entry *ent;
bool ret = false;
mutex_lock(&ei_mutex);
list_for_each_entry(ent, &error_injection_list, list) {
if (addr >= ent->start_addr && addr < ent->end_addr) {
ret = true;
break;
}
}
mutex_unlock(&ei_mutex);
return ret;
}
/*
* Lookup and populate the error_injection_list.
*
* For safety reasons we only allow certain functions to be overridden with
* bpf_error_injection, so we need to populate the list of the symbols that have
* been marked as safe for overriding.
*/
static void populate_error_injection_list(unsigned long *start,
unsigned long *end, void *priv)
{
unsigned long *iter;
struct ei_entry *ent;
unsigned long entry, offset = 0, size = 0;
mutex_lock(&ei_mutex);
for (iter = start; iter < end; iter++) {
entry = arch_deref_entry_point((void *)*iter);
if (!kernel_text_address(entry) ||
!kallsyms_lookup_size_offset(entry, &size, &offset)) {
pr_err("Failed to find error inject entry at %p\n",
(void *)entry);
continue;
}
ent = kmalloc(sizeof(*ent), GFP_KERNEL);
if (!ent)
break;
ent->start_addr = entry;
ent->end_addr = entry + size;
ent->priv = priv;
INIT_LIST_HEAD(&ent->list);
list_add_tail(&ent->list, &error_injection_list);
}
mutex_unlock(&ei_mutex);
}
/* Markers of the _error_inject_whitelist section */
extern unsigned long __start_error_injection_whitelist[];
extern unsigned long __stop_error_injection_whitelist[];
static void __init populate_kernel_ei_list(void)
{
populate_error_injection_list(__start_error_injection_whitelist,
__stop_error_injection_whitelist,
NULL);
}
#ifdef CONFIG_MODULES
static void module_load_ei_list(struct module *mod)
{
if (!mod->num_ei_funcs)
return;
populate_error_injection_list(mod->ei_funcs,
mod->ei_funcs + mod->num_ei_funcs, mod);
}
static void module_unload_ei_list(struct module *mod)
{
struct ei_entry *ent, *n;
if (!mod->num_ei_funcs)
return;
mutex_lock(&ei_mutex);
list_for_each_entry_safe(ent, n, &error_injection_list, list) {
if (ent->priv == mod) {
list_del_init(&ent->list);
kfree(ent);
}
}
mutex_unlock(&ei_mutex);
}
/* Module notifier call back, checking error injection table on the module */
static int ei_module_callback(struct notifier_block *nb,
unsigned long val, void *data)
{
struct module *mod = data;
if (val == MODULE_STATE_COMING)
module_load_ei_list(mod);
else if (val == MODULE_STATE_GOING)
module_unload_ei_list(mod);
return NOTIFY_DONE;
}
static struct notifier_block ei_module_nb = {
.notifier_call = ei_module_callback,
.priority = 0
};
static __init int module_ei_init(void)
{
return register_module_notifier(&ei_module_nb);
}
#else /* !CONFIG_MODULES */
#define module_ei_init() (0)
#endif
/*
* error_injection/whitelist -- shows which functions can be overridden for
* error injection.
*/
static void *ei_seq_start(struct seq_file *m, loff_t *pos)
{
mutex_lock(&ei_mutex);
return seq_list_start(&error_injection_list, *pos);
}
static void ei_seq_stop(struct seq_file *m, void *v)
{
mutex_unlock(&ei_mutex);
}
static void *ei_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &error_injection_list, pos);
}
static int ei_seq_show(struct seq_file *m, void *v)
{
struct ei_entry *ent = list_entry(v, struct ei_entry, list);
seq_printf(m, "%pf\n", (void *)ent->start_addr);
return 0;
}
static const struct seq_operations ei_seq_ops = {
.start = ei_seq_start,
.next = ei_seq_next,
.stop = ei_seq_stop,
.show = ei_seq_show,
};
static int ei_open(struct inode *inode, struct file *filp)
{
return seq_open(filp, &ei_seq_ops);
}
static const struct file_operations debugfs_ei_ops = {
.open = ei_open,
.read = seq_read,
.llseek = seq_lseek,
.release = seq_release,
};
static int __init ei_debugfs_init(void)
{
struct dentry *dir, *file;
dir = debugfs_create_dir("error_injection", NULL);
if (!dir)
return -ENOMEM;
file = debugfs_create_file("list", 0444, dir, NULL, &debugfs_ei_ops);
if (!file) {
debugfs_remove(dir);
return -ENOMEM;
}
return 0;
}
static int __init init_error_injection(void)
{
populate_kernel_ei_list();
if (!module_ei_init())
ei_debugfs_init();
return 0;
}
late_initcall(init_error_injection);