forked from mirrors/linux
4f6923fbb3
should_failslab() is a convenient function to hook into for directed
error injection into kmalloc(). However, it is only available if a
config flag is set.
The following BCC script, for example, fails kmalloc() calls after a
btrfs umount:
from bcc import BPF
prog = r"""
BPF_HASH(flag);
#include <linux/mm.h>
int kprobe__btrfs_close_devices(void *ctx) {
u64 key = 1;
flag.update(&key, &key);
return 0;
}
int kprobe__should_failslab(struct pt_regs *ctx) {
u64 key = 1;
u64 *res;
res = flag.lookup(&key);
if (res != 0) {
bpf_override_return(ctx, -ENOMEM);
}
return 0;
}
"""
b = BPF(text=prog)
while 1:
b.kprobe_poll()
This patch refactors the should_failslab implementation so that the
function is always available for error injection, independent of flags.
This change would be similar in nature to commit f5490d3ec921 ("block:
Add should_fail_bio() for bpf error injection").
Link: http://lkml.kernel.org/r/20180222020320.6944-1-hmclauchlan@fb.com
Signed-off-by: Howard McLauchlan <hmclauchlan@fb.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: Johannes Weiner <jweiner@fb.com>
Cc: Alexei Starovoitov <ast@fb.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
77 lines
1.9 KiB
C
77 lines
1.9 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
#ifndef _LINUX_FAULT_INJECT_H
|
|
#define _LINUX_FAULT_INJECT_H
|
|
|
|
#ifdef CONFIG_FAULT_INJECTION
|
|
|
|
#include <linux/types.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/ratelimit.h>
|
|
#include <linux/atomic.h>
|
|
|
|
/*
|
|
* For explanation of the elements of this struct, see
|
|
* Documentation/fault-injection/fault-injection.txt
|
|
*/
|
|
struct fault_attr {
|
|
unsigned long probability;
|
|
unsigned long interval;
|
|
atomic_t times;
|
|
atomic_t space;
|
|
unsigned long verbose;
|
|
bool task_filter;
|
|
unsigned long stacktrace_depth;
|
|
unsigned long require_start;
|
|
unsigned long require_end;
|
|
unsigned long reject_start;
|
|
unsigned long reject_end;
|
|
|
|
unsigned long count;
|
|
struct ratelimit_state ratelimit_state;
|
|
struct dentry *dname;
|
|
};
|
|
|
|
#define FAULT_ATTR_INITIALIZER { \
|
|
.interval = 1, \
|
|
.times = ATOMIC_INIT(1), \
|
|
.require_end = ULONG_MAX, \
|
|
.stacktrace_depth = 32, \
|
|
.ratelimit_state = RATELIMIT_STATE_INIT_DISABLED, \
|
|
.verbose = 2, \
|
|
.dname = NULL, \
|
|
}
|
|
|
|
#define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER
|
|
int setup_fault_attr(struct fault_attr *attr, char *str);
|
|
bool should_fail(struct fault_attr *attr, ssize_t size);
|
|
|
|
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
|
|
|
|
struct dentry *fault_create_debugfs_attr(const char *name,
|
|
struct dentry *parent, struct fault_attr *attr);
|
|
|
|
#else /* CONFIG_FAULT_INJECTION_DEBUG_FS */
|
|
|
|
static inline struct dentry *fault_create_debugfs_attr(const char *name,
|
|
struct dentry *parent, struct fault_attr *attr)
|
|
{
|
|
return ERR_PTR(-ENODEV);
|
|
}
|
|
|
|
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
|
|
|
|
#endif /* CONFIG_FAULT_INJECTION */
|
|
|
|
struct kmem_cache;
|
|
|
|
int should_failslab(struct kmem_cache *s, gfp_t gfpflags);
|
|
#ifdef CONFIG_FAILSLAB
|
|
extern bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags);
|
|
#else
|
|
static inline bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags)
|
|
{
|
|
return false;
|
|
}
|
|
#endif /* CONFIG_FAILSLAB */
|
|
|
|
#endif /* _LINUX_FAULT_INJECT_H */
|