1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/fault-inject.h> 3 #include <linux/slab.h> 4 #include <linux/mm.h> 5 #include "slab.h" 6 7 static struct { 8 struct fault_attr attr; 9 bool ignore_gfp_reclaim; 10 bool cache_filter; 11 } failslab = { 12 .attr = FAULT_ATTR_INITIALIZER, 13 .ignore_gfp_reclaim = true, 14 .cache_filter = false, 15 }; 16 17 bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags) 18 { 19 int flags = 0; 20 21 /* No fault-injection for bootstrap cache */ 22 if (unlikely(s == kmem_cache)) 23 return false; 24 25 if (gfpflags & __GFP_NOFAIL) 26 return false; 27 28 if (failslab.ignore_gfp_reclaim && 29 (gfpflags & __GFP_DIRECT_RECLAIM)) 30 return false; 31 32 if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB)) 33 return false; 34 35 /* 36 * In some cases, it expects to specify __GFP_NOWARN 37 * to avoid printing any information(not just a warning), 38 * thus avoiding deadlocks. See commit 6b9dbedbe349 for 39 * details. 40 */ 41 if (gfpflags & __GFP_NOWARN) 42 flags |= FAULT_NOWARN; 43 44 return should_fail_ex(&failslab.attr, s->object_size, flags); 45 } 46 47 static int __init setup_failslab(char *str) 48 { 49 return setup_fault_attr(&failslab.attr, str); 50 } 51 __setup("failslab=", setup_failslab); 52 53 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 54 static int __init failslab_debugfs_init(void) 55 { 56 struct dentry *dir; 57 umode_t mode = S_IFREG | 0600; 58 59 dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr); 60 if (IS_ERR(dir)) 61 return PTR_ERR(dir); 62 63 debugfs_create_bool("ignore-gfp-wait", mode, dir, 64 &failslab.ignore_gfp_reclaim); 65 debugfs_create_bool("cache-filter", mode, dir, 66 &failslab.cache_filter); 67 68 return 0; 69 } 70 71 late_initcall(failslab_debugfs_init); 72 73 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 74