// SPDX-License-Identifier: GPL-2.0 #include <linux/fault-inject.h> #include <linux/slab.h> #include <linux/mm.h> #include "slab.h" static struct { struct fault_attr attr; bool ignore_gfp_reclaim; bool cache_filter; } failslab = { .attr = FAULT_ATTR_INITIALIZER, .ignore_gfp_reclaim = true, .cache_filter = false, }; bool __should_failslab(struct kmem_cache *s, gfp_t gfpflags) { int flags = 0; /* No fault-injection for bootstrap cache */ if (unlikely(s == kmem_cache)) return false; if (gfpflags & __GFP_NOFAIL) return false; if (failslab.ignore_gfp_reclaim && (gfpflags & __GFP_DIRECT_RECLAIM)) return false; if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB)) return false; /* * In some cases, it expects to specify __GFP_NOWARN * to avoid printing any information(not just a warning), * thus avoiding deadlocks. See commit 6b9dbedbe349 for * details. */ if (gfpflags & __GFP_NOWARN) flags |= FAULT_NOWARN; return should_fail_ex(&failslab.attr, s->object_size, flags); } static int __init setup_failslab(char *str) { return setup_fault_attr(&failslab.attr, str); } __setup("failslab=", setup_failslab); #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS static int __init failslab_debugfs_init(void) { struct dentry *dir; umode_t mode = S_IFREG | 0600; dir = fault_create_debugfs_attr("failslab", NULL, &failslab.attr); if (IS_ERR(dir)) return PTR_ERR(dir); debugfs_create_bool("ignore-gfp-wait", mode, dir, &failslab.ignore_gfp_reclaim); debugfs_create_bool("cache-filter", mode, dir, &failslab.cache_filter); return 0; } late_initcall(failslab_debugfs_init); #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */