1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/fault-inject.h> 3 #include <linux/mm.h> 4 5 static struct { 6 struct fault_attr attr; 7 8 bool ignore_gfp_highmem; 9 bool ignore_gfp_reclaim; 10 u32 min_order; 11 } fail_page_alloc = { 12 .attr = FAULT_ATTR_INITIALIZER, 13 .ignore_gfp_reclaim = true, 14 .ignore_gfp_highmem = true, 15 .min_order = 1, 16 }; 17 18 static int __init setup_fail_page_alloc(char *str) 19 { 20 return setup_fault_attr(&fail_page_alloc.attr, str); 21 } 22 __setup("fail_page_alloc=", setup_fail_page_alloc); 23 24 bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 25 { 26 int flags = 0; 27 28 if (order < fail_page_alloc.min_order) 29 return false; 30 if (gfp_mask & __GFP_NOFAIL) 31 return false; 32 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 33 return false; 34 if (fail_page_alloc.ignore_gfp_reclaim && 35 (gfp_mask & __GFP_DIRECT_RECLAIM)) 36 return false; 37 38 /* See comment in __should_failslab() */ 39 if (gfp_mask & __GFP_NOWARN) 40 flags |= FAULT_NOWARN; 41 42 return should_fail_ex(&fail_page_alloc.attr, 1 << order, flags); 43 } 44 45 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 46 47 static int __init fail_page_alloc_debugfs(void) 48 { 49 umode_t mode = S_IFREG | 0600; 50 struct dentry *dir; 51 52 dir = fault_create_debugfs_attr("fail_page_alloc", NULL, 53 &fail_page_alloc.attr); 54 55 debugfs_create_bool("ignore-gfp-wait", mode, dir, 56 &fail_page_alloc.ignore_gfp_reclaim); 57 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 58 &fail_page_alloc.ignore_gfp_highmem); 59 debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order); 60 61 return 0; 62 } 63 64 late_initcall(fail_page_alloc_debugfs); 65 66 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 67