Kernel: Add ubsan

My brain has been melting since I'm getting very random bugs. I hope I can debug them better with ubsan :)
2023-03-06 23:38:05 +02:00
parent e480f9c195
commit 06db890d49
8 changed files with 128 additions and 12 deletions
--- a/kernel/ubsan.cpp
+++ b/kernel/ubsan.cpp
@@ -0,0 +1,108 @@
+#include <kernel/Debug.h>
+#include <kernel/Panic.h>
+
+extern "C"
+{
+
+	struct source_location
+	{
+		const char *file;
+		uint32_t line;
+		uint32_t column;
+	};
+	
+	struct type_descriptor
+	{
+		uint16_t kind;
+		uint16_t info;
+		char name[1];
+	};
+	
+	struct type_mismatch_data
+	{
+		source_location location;
+		const type_descriptor& type;
+		uint8_t alignment;
+		uint8_t type_check_kind;
+	};
+	
+	struct out_of_bounds_data
+	{
+		source_location location;
+		const type_descriptor& left_type;
+		const type_descriptor& right_type;
+	};
+
+	struct shift_out_of_bounds_data
+	{
+		source_location location;
+		const type_descriptor& left_type;
+		const type_descriptor& right_type;
+	};
+
+	struct pointer_overflow_data
+	{
+		source_location location;
+	};
+
+	struct invalid_value_data
+	{
+		source_location location;
+		const type_descriptor& type;
+	};
+
+	struct overflow_data
+	{
+		source_location location;
+		const type_descriptor& type;
+	};
+
+	using value_handle = uintptr_t;
+
+	static const char* type_check_kinds[] = {
+		"load of", "store to", "reference binding to", "member access within",
+		"member call on", "constructor call on", "downcast of", "downcast of",
+		"upcast of", "cast to virtual base of", "_Nonnull binding to",
+		"dynamic operation on"
+	};
+
+	#define HANDLER(handler, fatal, ...)															\
+		void handler(__VA_ARGS__)																	\
+		{																							\
+			if constexpr(fatal)																		\
+				Kernel::panic("{}:{} {}", data->location.file, data->location.line, __FUNCTION__);	\
+			else																					\
+				derrorln("{}:{} {}", data->location.file, data->location.line, __FUNCTION__);		\
+		}
+
+	static void print_location_impl(const source_location& location, const char* function)
+	{
+		derrorln("{}:{} {}", location.file, location.line, function);
+	}
+	#define print_location(location) print_location_impl(location, __FUNCTION__)
+
+	HANDLER(__ubsan_handle_pointer_overflow, false, pointer_overflow_data* data, value_handle, value_handle)
+	HANDLER(__ubsan_handle_load_invalid_value, false, invalid_value_data* data, value_handle)
+	HANDLER(__ubsan_handle_out_of_bounds, false, out_of_bounds_data* data, value_handle)
+	HANDLER(__ubsan_handle_shift_out_of_bounds, false, shift_out_of_bounds_data* data, value_handle, value_handle)
+
+	HANDLER(__ubsan_handle_add_overflow, false, overflow_data* data, value_handle, value_handle)
+	HANDLER(__ubsan_handle_sub_overflow, false, overflow_data* data, value_handle, value_handle)
+	HANDLER(__ubsan_handle_mul_overflow, false, overflow_data* data, value_handle, value_handle)
+	HANDLER(__ubsan_handle_divrem_overflow, false, overflow_data* data, value_handle, value_handle)
+	HANDLER(__ubsan_handle_negate_overflow, false, overflow_data* data, value_handle)
+
+	void __ubsan_handle_type_mismatch_v1(type_mismatch_data* data, value_handle pointer)
+	{
+		print_location(data->location);
+		const char* kind = type_check_kinds[data->type_check_kind];
+		uintptr_t alignment = (uintptr_t)1 << data->alignment;
+		if (!pointer)
+			derrorln("{} null pointer of type {}", kind, data->type.name);
+		else if (pointer & (alignment - 1))
+			derrorln("{} misaligned address {} for type {}, which requires {} byte alignment", kind, (void*)pointer, data->type.name, alignment);
+		else
+			derrorln("{} address {} with insufficient space for an object of type {}", kind, (void*)pointer, data->type.name);
+	}
+
+}