77 lines · c
1// SPDX-License-Identifier: GPL-2.02#include <linux/fault-inject.h>3#include <linux/error-injection.h>4#include <linux/debugfs.h>5#include <linux/slab.h>6#include <linux/mm.h>7#include "slab.h"8 9static struct {10 struct fault_attr attr;11 bool ignore_gfp_reclaim;12 bool cache_filter;13} failslab = {14 .attr = FAULT_ATTR_INITIALIZER,15 .ignore_gfp_reclaim = true,16 .cache_filter = false,17};18 19int should_failslab(struct kmem_cache *s, gfp_t gfpflags)20{21 int flags = 0;22 23 /* No fault-injection for bootstrap cache */24 if (unlikely(s == kmem_cache))25 return 0;26 27 if (gfpflags & __GFP_NOFAIL)28 return 0;29 30 if (failslab.ignore_gfp_reclaim &&31 (gfpflags & __GFP_DIRECT_RECLAIM))32 return 0;33 34 if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))35 return 0;36 37 /*38 * In some cases, it expects to specify __GFP_NOWARN39 * to avoid printing any information(not just a warning),40 * thus avoiding deadlocks. See commit 6b9dbedbe349 for41 * details.42 */43 if (gfpflags & __GFP_NOWARN)44 flags |= FAULT_NOWARN;45 46 return should_fail_ex(&failslab.attr, s->object_size, flags) ? -ENOMEM : 0;47}48ALLOW_ERROR_INJECTION(should_failslab, ERRNO);49 50static int __init setup_failslab(char *str)51{52 return setup_fault_attr(&failslab.attr, str);53}54__setup("failslab=", setup_failslab);55 56#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS57static int __init failslab_debugfs_init(void)58{59 struct dentry *dir;60 umode_t mode = S_IFREG | 0600;61 62 dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr);63 if (IS_ERR(dir))64 return PTR_ERR(dir);65 66 debugfs_create_bool("ignore-gfp-wait", mode, dir,67 &failslab.ignore_gfp_reclaim);68 debugfs_create_bool("cache-filter", mode, dir,69 &failslab.cache_filter);70 71 return 0;72}73 74late_initcall(failslab_debugfs_init);75 76#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */77