kasan: Add report for async mode

KASAN provides an asynchronous mode of execution. Add reporting functionality for this mode. Cc: Dmitry Vyukov <[email protected]> Cc: Andrey Ryabinin <[email protected]> Cc: Alexander Potapenko <[email protected]> Cc: Andrey Konovalov <[email protected]> Reviewed-by: Andrey Konovalov <[email protected]> Acked-by: Catalin Marinas <[email protected]> Acked-by: Andrey Konovalov <[email protected]> Tested-by: Andrey Konovalov <[email protected]> Signed-off-by: Vincenzo Frascino <[email protected]> Signed-off-by: Andrey Konovalov <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Catalin Marinas <[email protected]>
LoveHeat · Apr 11, 2021 · 8f7b505 · 8f7b505
1 parent c137c61
commit 8f7b505
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Showing 3 changed files with 38 additions and 1 deletion.
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
@@ -376,6 +376,12 @@ static inline void *kasan_reset_tag(const void *addr)
 
 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS*/
 
+#ifdef CONFIG_KASAN_HW_TAGS
+
+void kasan_report_async(void);
+
+#endif /* CONFIG_KASAN_HW_TAGS */
+
 #ifdef CONFIG_KASAN_SW_TAGS
 void __init kasan_init_sw_tags(void);
 #else

diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h
@@ -7,17 +7,33 @@
 #include <linux/stackdepot.h>
 
 #ifdef CONFIG_KASAN_HW_TAGS
+
 #include <linux/static_key.h>
+
 DECLARE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
+extern bool kasan_flag_async __ro_after_init;
+
 static inline bool kasan_stack_collection_enabled(void)
 {
 	return static_branch_unlikely(&kasan_flag_stacktrace);
 }
+
+static inline bool kasan_async_mode_enabled(void)
+{
+	return kasan_flag_async;
+}
 #else
+
 static inline bool kasan_stack_collection_enabled(void)
 {
 	return true;
 }
+
+static inline bool kasan_async_mode_enabled(void)
+{
+	return false;
+}
+
 #endif
 
 extern bool kasan_flag_panic __ro_after_init;

diff --git a/mm/kasan/report.c b/mm/kasan/report.c
@@ -87,7 +87,8 @@ static void start_report(unsigned long *flags)
 
 static void end_report(unsigned long *flags, unsigned long addr)
 {
-	trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
+	if (!kasan_async_mode_enabled())
+		trace_error_report_end(ERROR_DETECTOR_KASAN, addr);
 	pr_err("==================================================================\n");
 	add_taint(TAINT_BAD_PAGE, LOCKDEP_NOW_UNRELIABLE);
 	spin_unlock_irqrestore(&report_lock, *flags);
@@ -360,6 +361,20 @@ void kasan_report_invalid_free(void *object, unsigned long ip)
 	end_report(&flags, (unsigned long)object);
 }
 
+#ifdef CONFIG_KASAN_HW_TAGS
+void kasan_report_async(void)
+{
+	unsigned long flags;
+
+	start_report(&flags);
+	pr_err("BUG: KASAN: invalid-access\n");
+	pr_err("Asynchronous mode enabled: no access details available\n");
+	pr_err("\n");
+	dump_stack();
+	end_report(&flags, 0);
+}
+#endif /* CONFIG_KASAN_HW_TAGS */
+
 static void __kasan_report(unsigned long addr, size_t size, bool is_write,
 				unsigned long ip)
 {