diff options
| -rw-r--r-- | lib/Kconfig.debug | 7 | ||||
| -rw-r--r-- | mm/page_alloc.c | 87 |
2 files changed, 94 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c7f567a..c66b7b4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -424,6 +424,13 @@ config FAILSLAB help This option provides fault-injection capabilitiy for kmalloc. +config FAIL_PAGE_ALLOC + bool "Fault-injection capabilitiy for alloc_pages()" + depends on DEBUG_KERNEL + select FAULT_INJECTION + help + This option provides fault-injection capabilitiy for alloc_pages(). + config FAULT_INJECTION_DEBUG_FS bool "Debugfs entries for fault-injection capabilities" depends on FAULT_INJECTION && SYSFS diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 18f0e04..0cc8b43 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -40,6 +40,7 @@ #include <linux/sort.h> #include <linux/pfn.h> #include <linux/backing-dev.h> +#include <linux/fault-inject.h> #include <asm/tlbflush.h> #include <asm/div64.h> @@ -892,6 +893,89 @@ failed: #define ALLOC_HIGH 0x20 /* __GFP_HIGH set */ #define ALLOC_CPUSET 0x40 /* check for correct cpuset */ +#ifdef CONFIG_FAIL_PAGE_ALLOC + +static struct fail_page_alloc_attr { + struct fault_attr attr; + + u32 ignore_gfp_highmem; + u32 ignore_gfp_wait; + +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS + + struct dentry *ignore_gfp_highmem_file; + struct dentry *ignore_gfp_wait_file; + +#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ + +} fail_page_alloc = { + .attr = FAULT_ATTR_INITIALIZER, +}; + +static int __init setup_fail_page_alloc(char *str) +{ + return setup_fault_attr(&fail_page_alloc.attr, str); +} +__setup("fail_page_alloc=", setup_fail_page_alloc); + +static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) +{ + if (gfp_mask & __GFP_NOFAIL) + return 0; + if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM)) + return 0; + if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT)) + return 0; + + return should_fail(&fail_page_alloc.attr, 1 << order); +} + +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS + +static int __init fail_page_alloc_debugfs(void) +{ + mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; + struct dentry *dir; + int err; + + err = init_fault_attr_dentries(&fail_page_alloc.attr, + "fail_page_alloc"); + if (err) + return err; + dir = fail_page_alloc.attr.dentries.dir; + + fail_page_alloc.ignore_gfp_wait_file = + debugfs_create_bool("ignore-gfp-wait", mode, dir, + &fail_page_alloc.ignore_gfp_wait); + + fail_page_alloc.ignore_gfp_highmem_file = + debugfs_create_bool("ignore-gfp-highmem", mode, dir, + &fail_page_alloc.ignore_gfp_highmem); + + if (!fail_page_alloc.ignore_gfp_wait_file || + !fail_page_alloc.ignore_gfp_highmem_file) { + err = -ENOMEM; + debugfs_remove(fail_page_alloc.ignore_gfp_wait_file); + debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file); + cleanup_fault_attr_dentries(&fail_page_alloc.attr); + } + + return err; +} + +late_initcall(fail_page_alloc_debugfs); + +#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ + +#else /* CONFIG_FAIL_PAGE_ALLOC */ + +static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order) +{ + return 0; +} + +#endif /* CONFIG_FAIL_PAGE_ALLOC */ + /* * Return 1 if free pages are above 'mark'. This takes into account the order * of the allocation. @@ -1136,6 +1220,9 @@ __alloc_pages(gfp_t gfp_mask, unsigned int order, might_sleep_if(wait); + if (should_fail_alloc_page(gfp_mask, order)) + return NULL; + restart: z = zonelist->zones; /* the list of zones suitable for gfp_mask */ |