diff options
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 6 | ||||
| -rw-r--r-- | include/linux/kasan.h | 3 | ||||
| -rw-r--r-- | lib/test_kasan.c | 10 | ||||
| -rw-r--r-- | mm/kasan/kasan.h | 5 | ||||
| -rw-r--r-- | mm/kasan/report.c | 36 |
5 files changed, 55 insertions, 5 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 2ba45caabada..facc20a3f962 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -1725,6 +1725,12 @@ kernel and module base offset ASLR (Address Space Layout Randomization). + kasan_multi_shot + [KNL] Enforce KASAN (Kernel Address Sanitizer) to print + report on every invalid memory access. Without this + parameter KASAN will print report only for the first + invalid access. + keepinitrd [HW,ARM] kernelcore= [KNL,X86,IA-64,PPC] diff --git a/include/linux/kasan.h b/include/linux/kasan.h index 5734480c9590..a5c7046f26b4 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -76,6 +76,9 @@ size_t ksize(const void *); static inline void kasan_unpoison_slab(const void *ptr) { ksize(ptr); } size_t kasan_metadata_size(struct kmem_cache *cache); +bool kasan_save_enable_multi_shot(void); +void kasan_restore_multi_shot(bool enabled); + #else /* CONFIG_KASAN */ static inline void kasan_unpoison_shadow(const void *address, size_t size) {} diff --git a/lib/test_kasan.c b/lib/test_kasan.c index 0b1d3140fbb8..a25c9763fce1 100644 --- a/lib/test_kasan.c +++ b/lib/test_kasan.c @@ -20,6 +20,7 @@ #include <linux/string.h> #include <linux/uaccess.h> #include <linux/module.h> +#include <linux/kasan.h> /* * Note: test functions are marked noinline so that their names appear in @@ -474,6 +475,12 @@ static noinline void __init use_after_scope_test(void) static int __init kmalloc_tests_init(void) { + /* + * Temporarily enable multi-shot mode. Otherwise, we'd only get a + * report for the first case. + */ + bool multishot = kasan_save_enable_multi_shot(); + kmalloc_oob_right(); kmalloc_oob_left(); kmalloc_node_oob_right(); @@ -499,6 +506,9 @@ static int __init kmalloc_tests_init(void) ksize_unpoisons_memory(); copy_user_test(); use_after_scope_test(); + + kasan_restore_multi_shot(multishot); + return -EAGAIN; } diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 1c260e6b3b3c..dd2dea8eb077 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -96,11 +96,6 @@ static inline const void *kasan_shadow_to_mem(const void *shadow_addr) << KASAN_SHADOW_SCALE_SHIFT); } -static inline bool kasan_report_enabled(void) -{ - return !current->kasan_depth; -} - void kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip); void kasan_report_double_free(struct kmem_cache *cache, void *object, diff --git a/mm/kasan/report.c b/mm/kasan/report.c index f479365530b6..ab42a0803f16 100644 --- a/mm/kasan/report.c +++ b/mm/kasan/report.c @@ -13,7 +13,9 @@ * */ +#include <linux/bitops.h> #include <linux/ftrace.h> +#include <linux/init.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/printk.h> @@ -293,6 +295,40 @@ static void kasan_report_error(struct kasan_access_info *info) kasan_end_report(&flags); } +static unsigned long kasan_flags; + +#define KASAN_BIT_REPORTED 0 +#define KASAN_BIT_MULTI_SHOT 1 + +bool kasan_save_enable_multi_shot(void) +{ + return test_and_set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); +} +EXPORT_SYMBOL_GPL(kasan_save_enable_multi_shot); + +void kasan_restore_multi_shot(bool enabled) +{ + if (!enabled) + clear_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); +} +EXPORT_SYMBOL_GPL(kasan_restore_multi_shot); + +static int __init kasan_set_multi_shot(char *str) +{ + set_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags); + return 1; +} +__setup("kasan_multi_shot", kasan_set_multi_shot); + +static inline bool kasan_report_enabled(void) +{ + if (current->kasan_depth) + return false; + if (test_bit(KASAN_BIT_MULTI_SHOT, &kasan_flags)) + return true; + return !test_and_set_bit(KASAN_BIT_REPORTED, &kasan_flags); +} + void kasan_report(unsigned long addr, size_t size, bool is_write, unsigned long ip) { |