diff options
Diffstat (limited to 'mm/kfence')
| -rw-r--r-- | mm/kfence/core.c | 40 | ||||
| -rw-r--r-- | mm/kfence/kfence_test.c | 5 |
2 files changed, 41 insertions, 4 deletions
diff --git a/mm/kfence/core.c b/mm/kfence/core.c index 11a954763be9..4e7cd4c8e687 100644 --- a/mm/kfence/core.c +++ b/mm/kfence/core.c @@ -21,6 +21,8 @@ #include <linux/log2.h> #include <linux/memblock.h> #include <linux/moduleparam.h> +#include <linux/notifier.h> +#include <linux/panic_notifier.h> #include <linux/random.h> #include <linux/rcupdate.h> #include <linux/sched/clock.h> @@ -67,8 +69,11 @@ static int param_set_sample_interval(const char *val, const struct kernel_param if (ret < 0) return ret; - if (!num) /* Using 0 to indicate KFENCE is disabled. */ + /* Using 0 to indicate KFENCE is disabled. */ + if (!num && READ_ONCE(kfence_enabled)) { + pr_info("disabled\n"); WRITE_ONCE(kfence_enabled, false); + } *((unsigned long *)kp->arg) = num; @@ -99,6 +104,10 @@ module_param_named(skip_covered_thresh, kfence_skip_covered_thresh, ulong, 0644) static bool kfence_deferrable __read_mostly = IS_ENABLED(CONFIG_KFENCE_DEFERRABLE); module_param_named(deferrable, kfence_deferrable, bool, 0444); +/* If true, check all canary bytes on panic. */ +static bool kfence_check_on_panic __read_mostly; +module_param_named(check_on_panic, kfence_check_on_panic, bool, 0444); + /* The pool of pages used for guard pages and objects. */ char *__kfence_pool __read_mostly; EXPORT_SYMBOL(__kfence_pool); /* Export for test modules. */ @@ -737,6 +746,31 @@ static int __init kfence_debugfs_init(void) late_initcall(kfence_debugfs_init); +/* === Panic Notifier ====================================================== */ + +static void kfence_check_all_canary(void) +{ + int i; + + for (i = 0; i < CONFIG_KFENCE_NUM_OBJECTS; i++) { + struct kfence_metadata *meta = &kfence_metadata[i]; + + if (meta->state == KFENCE_OBJECT_ALLOCATED) + for_each_canary(meta, check_canary_byte); + } +} + +static int kfence_check_canary_callback(struct notifier_block *nb, + unsigned long reason, void *arg) +{ + kfence_check_all_canary(); + return NOTIFY_OK; +} + +static struct notifier_block kfence_check_canary_notifier = { + .notifier_call = kfence_check_canary_callback, +}; + /* === Allocation Gate Timer ================================================ */ static struct delayed_work kfence_timer; @@ -814,6 +848,9 @@ static void kfence_init_enable(void) else INIT_DELAYED_WORK(&kfence_timer, toggle_allocation_gate); + if (kfence_check_on_panic) + atomic_notifier_chain_register(&panic_notifier_list, &kfence_check_canary_notifier); + WRITE_ONCE(kfence_enabled, true); queue_delayed_work(system_unbound_wq, &kfence_timer, 0); @@ -874,6 +911,7 @@ static int kfence_enable_late(void) WRITE_ONCE(kfence_enabled, true); queue_delayed_work(system_unbound_wq, &kfence_timer, 0); + pr_info("re-enabled\n"); return 0; } diff --git a/mm/kfence/kfence_test.c b/mm/kfence/kfence_test.c index 96206a4ee9ab..a97bffe0cc3e 100644 --- a/mm/kfence/kfence_test.c +++ b/mm/kfence/kfence_test.c @@ -296,10 +296,9 @@ static void *test_alloc(struct kunit *test, size_t size, gfp_t gfp, enum allocat if (policy == ALLOCATE_ANY) return alloc; - if (policy == ALLOCATE_LEFT && IS_ALIGNED((unsigned long)alloc, PAGE_SIZE)) + if (policy == ALLOCATE_LEFT && PAGE_ALIGNED(alloc)) return alloc; - if (policy == ALLOCATE_RIGHT && - !IS_ALIGNED((unsigned long)alloc, PAGE_SIZE)) + if (policy == ALLOCATE_RIGHT && !PAGE_ALIGNED(alloc)) return alloc; } else if (policy == ALLOCATE_NONE) return alloc; |