path: root/src/lib/ubsan.c

/* SPDX-License-Identifier: ISC */
/* ubsan/ubsan.c
 * Undefined behavior sanitizer runtime support.
 *
 * Adapted from:
 * https://gitlab.com/sortix/sortix/raw/master/libc/ubsan/ubsan.c
 */

#include <stdint.h>
#include <console/console.h>

struct ubsan_source_location {
	const char *filename;
	uint32_t line;
	uint32_t column;
};

struct ubsan_type_descriptor {
	uint16_t type_kind;
	uint16_t type_info;
	char type_name[];
};

typedef uintptr_t ubsan_value_handle_t;

/*
*  Keep the compiler happy -- it wants prototypes but nobody
*  except the compiler should be touching these functions.
*/
#pragma GCC diagnostic ignored "-Wmissing-prototypes"

static void __noreturn ubsan_abort(const struct ubsan_source_location *location,
			const char *violation) {
	static const struct ubsan_source_location unknown_location = {
		"<unknown file>",
		0,
		0,
	};

	if (!location || !location->filename)
		location = &unknown_location;
	printk(BIOS_ERR, "%s %s:%lu:%lu\n", violation, location->filename,
		(unsigned long int)location->line,
		(unsigned long int)location->column);
	die("ubsan: unrecoverable error.\n");
}

#define ABORT_VARIANT(name, params, call) \
	__noreturn void __ubsan_handle_##name##_abort params; \
	__noreturn void __ubsan_handle_##name##_abort params { \
		__ubsan_handle_##name call; \
		__builtin_unreachable(); \
	}

#define ABORT_VARIANT_VP(name) \
	ABORT_VARIANT(name, (void *a), (a))
#define ABORT_VARIANT_VP_VP(name) \
	ABORT_VARIANT(name, (void *a, void *b), (a, b))
#define ABORT_VARIANT_VP_IP(name) \
	ABORT_VARIANT(name, (void *a, intptr_t b), (a, b))
#define ABORT_VARIANT_VP_VP_VP(name) \
	ABORT_VARIANT(name, (void *a, void *b, void *c), (a, b, c))

struct ubsan_type_mismatch_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *type;
	uintptr_t alignment;
	unsigned char type_check_kind;
};

void __ubsan_handle_type_mismatch(void *data_raw, void *pointer_raw)
{
	const struct ubsan_type_mismatch_data *data =
		(struct ubsan_type_mismatch_data *)data_raw;
	ubsan_value_handle_t pointer = (ubsan_value_handle_t)pointer_raw;
	const char *violation = "type mismatch";
	if (!pointer)
		violation = "null pointer access";
	else if (data->alignment && (pointer & (data->alignment - 1)))
		violation = "unaligned access";
	ubsan_abort(&data->location, violation);
}

ABORT_VARIANT_VP_VP(type_mismatch);

struct ubsan_overflow_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *type;
};

void __ubsan_handle_add_overflow(void *data_raw, void *lhs_raw,
				 void *rhs_raw)
{
	const struct ubsan_overflow_data *data
		= (struct ubsan_overflow_data *)data_raw;
	ubsan_value_handle_t lhs = (ubsan_value_handle_t)lhs_raw;
	ubsan_value_handle_t rhs = (ubsan_value_handle_t)rhs_raw;
	(void)lhs;
	(void)rhs;
	ubsan_abort(&data->location, "addition overflow");
}

ABORT_VARIANT_VP_VP_VP(add_overflow);

void __ubsan_handle_sub_overflow(void *data_raw, void *lhs_raw,
				 void *rhs_raw)
{
	const struct ubsan_overflow_data *data
		= (struct ubsan_overflow_data *)data_raw;
	ubsan_value_handle_t lhs = (ubsan_value_handle_t)lhs_raw;
	ubsan_value_handle_t rhs = (ubsan_value_handle_t)rhs_raw;
	(void)lhs;
	(void)rhs;
	ubsan_abort(&data->location, "subtraction overflow");
}

ABORT_VARIANT_VP_VP_VP(sub_overflow);

void __ubsan_handle_mul_overflow(void *data_raw, void *lhs_raw,
				 void *rhs_raw)
{
	const struct ubsan_overflow_data *data
		= (struct ubsan_overflow_data *)data_raw;
	ubsan_value_handle_t lhs = (ubsan_value_handle_t)lhs_raw;
	ubsan_value_handle_t rhs = (ubsan_value_handle_t)rhs_raw;
	(void)lhs;
	(void)rhs;
	ubsan_abort(&data->location, "multiplication overflow");
}

ABORT_VARIANT_VP_VP_VP(mul_overflow);

void __ubsan_handle_negate_overflow(void *data_raw, void *old_value_raw)
{
	const struct ubsan_overflow_data *data
		= (struct ubsan_overflow_data *)data_raw;
	ubsan_value_handle_t old_value
		= (ubsan_value_handle_t)old_value_raw;
	(void) old_value;
	ubsan_abort(&data->location, "negation overflow");
}

ABORT_VARIANT_VP_VP(negate_overflow);

void __ubsan_handle_divrem_overflow(void *data_raw, void *lhs_raw,
					void *rhs_raw)
{
	const struct ubsan_overflow_data *data
		= (struct ubsan_overflow_data *)data_raw;
	ubsan_value_handle_t lhs = (ubsan_value_handle_t)lhs_raw;
	ubsan_value_handle_t rhs = (ubsan_value_handle_t)rhs_raw;
	(void)lhs;
	(void)rhs;
	ubsan_abort(&data->location, "division remainder overflow");
}

ABORT_VARIANT_VP_VP_VP(divrem_overflow);

struct ubsan_shift_out_of_bounds_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *lhs_type;
	struct ubsan_type_descriptor *rhs_type;
};

void __ubsan_handle_shift_out_of_bounds(void *data_raw, void *lhs_raw,
					void *rhs_raw)
{
	const struct ubsan_shift_out_of_bounds_data *data =
		(struct ubsan_shift_out_of_bounds_data *)data_raw;
	ubsan_value_handle_t lhs = (ubsan_value_handle_t)lhs_raw;
	ubsan_value_handle_t rhs = (ubsan_value_handle_t)rhs_raw;
	(void)lhs;
	(void)rhs;
	ubsan_abort(&data->location, "shift out of bounds");
}

ABORT_VARIANT_VP_VP_VP(shift_out_of_bounds);

struct ubsan_out_of_bounds_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *array_type;
	struct ubsan_type_descriptor *index_type;
};

void __ubsan_handle_out_of_bounds(void *data_raw, void *index_raw)
{
	const struct ubsan_out_of_bounds_data *data =
		(struct ubsan_out_of_bounds_data *)data_raw;
	ubsan_value_handle_t index = (ubsan_value_handle_t)index_raw;
	(void)index;
	ubsan_abort(&data->location, "out of bounds");
}

ABORT_VARIANT_VP_VP(out_of_bounds);

struct ubsan_unreachable_data {
	struct ubsan_source_location location;
};

void __noreturn __ubsan_handle_builtin_unreachable(void *data_raw)
{
	struct ubsan_unreachable_data *data =
		(struct ubsan_unreachable_data *)data_raw;
	ubsan_abort(&data->location, "reached unreachable");
}

void __noreturn __ubsan_handle_missing_return(void *data_raw)
{
	const struct ubsan_unreachable_data *data =
		(struct ubsan_unreachable_data *)data_raw;
	ubsan_abort(&data->location, "missing return");
}

struct ubsan_vla_bound_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *type;
};

void __ubsan_handle_vla_bound_not_positive(void *data_raw, void *bound_raw)
{
	const struct ubsan_vla_bound_data *data
		= (struct ubsan_vla_bound_data *)data_raw;
	ubsan_value_handle_t bound = (ubsan_value_handle_t)bound_raw;
	(void)bound;
	ubsan_abort(&data->location, "negative variable array length");
}

ABORT_VARIANT_VP_VP(vla_bound_not_positive);

struct ubsan_float_cast_overflow_data {
/*
* TODO: Remove this GCC 5.x compatibility after switching to GCC 6.x. The
* GCC developers accidentally forgot the source location. Their
* libubsan probes to see if it looks like a path, but we don't need
* to maintain compatibility with multiple gcc releases. See below.
*/
#if !(defined(__GNUC__) && __GNUC__ < 6)
	struct ubsan_source_location location;
#endif
	struct ubsan_type_descriptor *from_type;
	struct ubsan_type_descriptor *to_type;
};

void __ubsan_handle_float_cast_overflow(void *data_raw, void *from_raw)
{
	struct ubsan_float_cast_overflow_data *data =
		(struct ubsan_float_cast_overflow_data *)data_raw;
	ubsan_value_handle_t from = (ubsan_value_handle_t)from_raw;
	(void) from;
#if !(defined(__GNUC__) && __GNUC__ < 6)
	ubsan_abort(&data->location, "float cast overflow");
#else
	ubsan_abort(((void) data, &unknown_location), "float cast overflow");
#endif
}

ABORT_VARIANT_VP_VP(float_cast_overflow);

struct ubsan_invalid_value_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *type;
};

void __ubsan_handle_load_invalid_value(void *data_raw, void *value_raw)
{
	const struct ubsan_invalid_value_data *data =
		(struct ubsan_invalid_value_data *)data_raw;
	ubsan_value_handle_t value = (ubsan_value_handle_t)value_raw;
	(void)value;
	ubsan_abort(&data->location, "invalid value load");
}

ABORT_VARIANT_VP_VP(load_invalid_value);

struct ubsan_function_type_mismatch_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *type;
};

void __ubsan_handle_function_type_mismatch(void *data_raw, void *value_raw)
{
	const struct ubsan_function_type_mismatch_data *data =
		(struct ubsan_function_type_mismatch_data *)data_raw;
	ubsan_value_handle_t value = (ubsan_value_handle_t)value_raw;
	(void)value;
	ubsan_abort(&data->location, "function type mismatch");
}

ABORT_VARIANT_VP_VP(function_type_mismatch);

struct ubsan_nonnull_return_data {
	struct ubsan_source_location location;
	struct ubsan_source_location attr_location;
};

void __ubsan_handle_nonnull_return(void *data_raw)
{
	const struct ubsan_nonnull_return_data *data =
		(struct ubsan_nonnull_return_data *)data_raw;
	ubsan_abort(&data->location, "null return");
}

ABORT_VARIANT_VP(nonnull_return);

struct ubsan_nonnull_arg_data {
	struct ubsan_source_location location;
	struct ubsan_source_location attr_location;
};

/*
*  TODO: GCC's libubsan does not have the second parameter, but its builtin
*  somehow has it and conflict if we don't match it.
*/
void __ubsan_handle_nonnull_arg(void *data_raw, intptr_t index_raw)
{
	const struct ubsan_nonnull_arg_data *data =
		(struct ubsan_nonnull_arg_data *)data_raw;
	ubsan_value_handle_t index = (ubsan_value_handle_t)index_raw;
	(void)index;
	ubsan_abort(&data->location, "null argument");
}

ABORT_VARIANT_VP_IP(nonnull_arg);

struct ubsan_cfi_bad_icall_data {
	struct ubsan_source_location location;
	struct ubsan_type_descriptor *type;
};

void __ubsan_handle_cfi_bad_icall(void *data_raw, void *value_raw)
{
	static const char *abort_text
		= "cfi: integrity failure during indirect call.";
	const struct ubsan_cfi_bad_icall_data *data =
		(struct ubsan_cfi_bad_icall_data *)data_raw;
	ubsan_value_handle_t value = (ubsan_value_handle_t)value_raw;
	(void)value;
	ubsan_abort(&data->location, abort_text);
}

ABORT_VARIANT_VP_VP(cfi_bad_icall);