diff options
| -rw-r--r-- | Documentation/fault-injection/fault-injection.txt | 2 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 7 | ||||
| -rw-r--r-- | mm/slab.c | 77 |
3 files changed, 84 insertions, 2 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt index 260ce6c199ce..cf075c20eda0 100644 --- a/Documentation/fault-injection/fault-injection.txt +++ b/Documentation/fault-injection/fault-injection.txt @@ -86,7 +86,6 @@ configuration of fault-injection capabilities. specifies the maximum stacktrace depth walked during search for a caller within [address-start,address-end). -- /debug/failslab/ignore-gfp-highmem: - /debug/fail_page_alloc/ignore-gfp-highmem: Format: { 0 | 1 } @@ -167,7 +166,6 @@ echo 10 > /debug/$FAILNAME/probability echo 100 > /debug/$FAILNAME/interval echo -1 > /debug/$FAILNAME/times echo 2 > /debug/$FAILNAME/verbose -echo 1 > /debug/$FAILNAME/ignore-gfp-highmem echo 1 > /debug/$FAILNAME/ignore-gfp-wait blacklist() diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 35228b3e7e92..c7f567a57d7d 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -417,6 +417,13 @@ config LKDTM config FAULT_INJECTION bool +config FAILSLAB + bool "Fault-injection capabilitiy for kmalloc" + depends on DEBUG_KERNEL + select FAULT_INJECTION + help + This option provides fault-injection capabilitiy for kmalloc. + config FAULT_INJECTION_DEBUG_FS bool "Debugfs entries for fault-injection capabilities" depends on FAULT_INJECTION && SYSFS diff --git a/mm/slab.c b/mm/slab.c index e90b6100a927..47011e2ef3c9 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -107,6 +107,7 @@ #include <linux/nodemask.h> #include <linux/mempolicy.h> #include <linux/mutex.h> +#include <linux/fault-inject.h> #include <linux/rtmutex.h> #include <asm/cacheflush.h> @@ -3088,12 +3089,88 @@ static void *cache_alloc_debugcheck_after(struct kmem_cache *cachep, #define cache_alloc_debugcheck_after(a,b,objp,d) (objp) #endif +#ifdef CONFIG_FAILSLAB + +static struct failslab_attr { + + struct fault_attr attr; + + u32 ignore_gfp_wait; +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS + struct dentry *ignore_gfp_wait_file; +#endif + +} failslab = { + .attr = FAULT_ATTR_INITIALIZER, +}; + +static int __init setup_failslab(char *str) +{ + return setup_fault_attr(&failslab.attr, str); +} +__setup("failslab=", setup_failslab); + +static int should_failslab(struct kmem_cache *cachep, gfp_t flags) +{ + if (cachep == &cache_cache) + return 0; + if (flags & __GFP_NOFAIL) + return 0; + if (failslab.ignore_gfp_wait && (flags & __GFP_WAIT)) + return 0; + + return should_fail(&failslab.attr, obj_size(cachep)); +} + +#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS + +static int __init failslab_debugfs(void) +{ + mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; + struct dentry *dir; + int err; + + err = init_fault_attr_dentries(&failslab.attr, "failslab"); + if (err) + return err; + dir = failslab.attr.dentries.dir; + + failslab.ignore_gfp_wait_file = + debugfs_create_bool("ignore-gfp-wait", mode, dir, + &failslab.ignore_gfp_wait); + + if (!failslab.ignore_gfp_wait_file) { + err = -ENOMEM; + debugfs_remove(failslab.ignore_gfp_wait_file); + cleanup_fault_attr_dentries(&failslab.attr); + } + + return err; +} + +late_initcall(failslab_debugfs); + +#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */ + +#else /* CONFIG_FAILSLAB */ + +static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags) +{ + return 0; +} + +#endif /* CONFIG_FAILSLAB */ + static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) { void *objp; struct array_cache *ac; check_irq_off(); + + if (should_failslab(cachep, flags)) + return NULL; + ac = cpu_cache_get(cachep); if (likely(ac->avail)) { STATS_INC_ALLOCHIT(cachep); |