| 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(attr: &failslab.attr, size: s->object_size, flags); |
| 45 | } |
| 46 | |
| 47 | static int __init setup_failslab(char *str) |
| 48 | { |
| 49 | return setup_fault_attr(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(name: "failslab", NULL, attr: &failslab.attr); |
| 60 | if (IS_ERR(ptr: dir)) |
| 61 | return PTR_ERR(ptr: dir); |
| 62 | |
| 63 | debugfs_create_bool(name: "ignore-gfp-wait", mode, parent: dir, |
| 64 | value: &failslab.ignore_gfp_reclaim); |
| 65 | debugfs_create_bool(name: "cache-filter", mode, parent: dir, |
| 66 | value: &failslab.cache_filter); |
| 67 | |
| 68 | return 0; |
| 69 | } |
| 70 | |
| 71 | late_initcall(failslab_debugfs_init); |
| 72 | |
| 73 | #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ |
| 74 |