1 // SPDX-License-Identifier: GPL-2.0 2 #include <linux/fault-inject.h> 3 #include <linux/debugfs.h> 4 #include <linux/error-injection.h> 5 #include <linux/mm.h> 6 7 static struct { 8 struct fault_attr attr; 9 10 bool ignore_gfp_highmem; 11 bool ignore_gfp_reclaim; 12 u32 min_order; 13 } fail_page_alloc = { 14 .attr = FAULT_ATTR_INITIALIZER, 15 .ignore_gfp_reclaim = true, 16 .ignore_gfp_highmem = true, 17 .min_order = 1, 18 }; 19 20 static int __init setup_fail_page_alloc(char *str) 21 { 22 return setup_fault_attr(&fail_page_alloc.attr, str); 23 } 24 __setup("fail_page_alloc=", setup_fail_page_alloc); 25 26 bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) 27 { 28 int flags = 0; 29 30 if (order < fail_page_alloc.min_order) 31 return false; 32 if (gfp_mask & __GFP_NOFAIL) 33 return false; 34 if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) 35 return false; 36 if (fail_page_alloc.ignore_gfp_reclaim && 37 (gfp_mask & __GFP_DIRECT_RECLAIM)) 38 return false; 39 40 /* See comment in __should_failslab() */ 41 if (gfp_mask & __GFP_NOWARN) 42 flags |= FAULT_NOWARN; 43 44 return should_fail_ex(&fail_page_alloc.attr, 1 << order, flags); 45 } 46 ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE); 47 48 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS 49 50 static int __init fail_page_alloc_debugfs(void) 51 { 52 umode_t mode = S_IFREG | 0600; 53 struct dentry *dir; 54 55 dir = fault_create_debugfs_attr("fail_page_alloc", NULL, 56 &fail_page_alloc.attr); 57 58 debugfs_create_bool("ignore-gfp-wait", mode, dir, 59 &fail_page_alloc.ignore_gfp_reclaim); 60 debugfs_create_bool("ignore-gfp-highmem", mode, dir, 61 &fail_page_alloc.ignore_gfp_highmem); 62 debugfs_create_u32("min-order", mode, dir, &fail_page_alloc.min_order); 63 64 return 0; 65 } 66 67 late_initcall(fail_page_alloc_debugfs); 68 69 #endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ 70