summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
-rw-r--r--Documentation/admin-guide/kernel-parameters.txt6
-rw-r--r--include/linux/kasan.h3
-rw-r--r--lib/test_kasan.c10
-rw-r--r--mm/kasan/kasan.h5
-rw-r--r--mm/kasan/report.c36
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)
{