[linux-block.git] / lib / ubsan.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * UBSAN error reporting functions
 *
 * Copyright (c) 2014 Samsung Electronics Co., Ltd.
 * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
 */

#include <linux/bitops.h>
#include <linux/bug.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/sched.h>
#include <linux/uaccess.h>
#include <linux/ubsan.h>
#include <kunit/test-bug.h>

#include "ubsan.h"

#if defined(CONFIG_UBSAN_TRAP) || defined(CONFIG_UBSAN_KVM_EL2)
/*
 * Only include matches for UBSAN checks that are actually compiled in.
 * The mappings of struct SanitizerKind (the -fsanitize=xxx args) to
 * enum SanitizerHandler (the traps) in Clang is in clang/lib/CodeGen/.
 */
const char *report_ubsan_failure(u32 check_type)
{
	switch (check_type) {
#ifdef CONFIG_UBSAN_BOUNDS
	/*
	 * SanitizerKind::ArrayBounds and SanitizerKind::LocalBounds
	 * emit SanitizerHandler::OutOfBounds.
	 */
	case ubsan_out_of_bounds:
		return "UBSAN: array index out of bounds";
#endif
#ifdef CONFIG_UBSAN_SHIFT
	/*
	 * SanitizerKind::ShiftBase and SanitizerKind::ShiftExponent
	 * emit SanitizerHandler::ShiftOutOfBounds.
	 */
	case ubsan_shift_out_of_bounds:
		return "UBSAN: shift out of bounds";
#endif
#if defined(CONFIG_UBSAN_DIV_ZERO) || defined(CONFIG_UBSAN_INTEGER_WRAP)
	/*
	 * SanitizerKind::IntegerDivideByZero and
	 * SanitizerKind::SignedIntegerOverflow emit
	 * SanitizerHandler::DivremOverflow.
	 */
	case ubsan_divrem_overflow:
		return "UBSAN: divide/remainder overflow";
#endif
#ifdef CONFIG_UBSAN_UNREACHABLE
	/*
	 * SanitizerKind::Unreachable emits
	 * SanitizerHandler::BuiltinUnreachable.
	 */
	case ubsan_builtin_unreachable:
		return "UBSAN: unreachable code";
#endif
#if defined(CONFIG_UBSAN_BOOL) || defined(CONFIG_UBSAN_ENUM)
	/*
	 * SanitizerKind::Bool and SanitizerKind::Enum emit
	 * SanitizerHandler::LoadInvalidValue.
	 */
	case ubsan_load_invalid_value:
		return "UBSAN: loading invalid value";
#endif
#ifdef CONFIG_UBSAN_ALIGNMENT
	/*
	 * SanitizerKind::Alignment emits SanitizerHandler::TypeMismatch
	 * or SanitizerHandler::AlignmentAssumption.
	 */
	case ubsan_alignment_assumption:
		return "UBSAN: alignment assumption";
	case ubsan_type_mismatch:
		return "UBSAN: type mismatch";
#endif
#ifdef CONFIG_UBSAN_INTEGER_WRAP
	/*
	 * SanitizerKind::SignedIntegerOverflow emits
	 * SanitizerHandler::AddOverflow, SanitizerHandler::SubOverflow,
	 * or SanitizerHandler::MulOverflow.
	 */
	case ubsan_add_overflow:
		return "UBSAN: integer addition overflow";
	case ubsan_sub_overflow:
		return "UBSAN: integer subtraction overflow";
	case ubsan_mul_overflow:
		return "UBSAN: integer multiplication overflow";
#endif
	default:
		return "UBSAN: unrecognized failure code";
	}
}

#endif

#ifndef CONFIG_UBSAN_TRAP
static const char * const type_check_kinds[] = {
	"load of",
	"store to",
	"reference binding to",
	"member access within",
	"member call on",
	"constructor call on",
	"downcast of",
	"downcast of"
};

#define REPORTED_BIT 31

#if (BITS_PER_LONG == 64) && defined(__BIG_ENDIAN)
#define COLUMN_MASK (~(1U << REPORTED_BIT))
#define LINE_MASK   (~0U)
#else
#define COLUMN_MASK   (~0U)
#define LINE_MASK (~(1U << REPORTED_BIT))
#endif

#define VALUE_LENGTH 40

static bool was_reported(struct source_location *location)
{
	return test_and_set_bit(REPORTED_BIT, &location->reported);
}

static bool suppress_report(struct source_location *loc)
{
	return current->in_ubsan || was_reported(loc);
}

static bool type_is_int(struct type_descriptor *type)
{
	return type->type_kind == type_kind_int;
}

static bool type_is_signed(struct type_descriptor *type)
{
	WARN_ON(!type_is_int(type));
	return  type->type_info & 1;
}

static unsigned type_bit_width(struct type_descriptor *type)
{
	return 1 << (type->type_info >> 1);
}

static bool is_inline_int(struct type_descriptor *type)
{
	unsigned inline_bits = sizeof(unsigned long)*8;
	unsigned bits = type_bit_width(type);

	WARN_ON(!type_is_int(type));

	return bits <= inline_bits;
}

static s_max get_signed_val(struct type_descriptor *type, void *val)
{
	if (is_inline_int(type)) {
		unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
		unsigned long ulong_val = (unsigned long)val;

		return ((s_max)ulong_val) << extra_bits >> extra_bits;
	}

	if (type_bit_width(type) == 64)
		return *(s64 *)val;

	return *(s_max *)val;
}

static bool val_is_negative(struct type_descriptor *type, void *val)
{
	return type_is_signed(type) && get_signed_val(type, val) < 0;
}

static u_max get_unsigned_val(struct type_descriptor *type, void *val)
{
	if (is_inline_int(type))
		return (unsigned long)val;

	if (type_bit_width(type) == 64)
		return *(u64 *)val;

	return *(u_max *)val;
}

static void val_to_string(char *str, size_t size, struct type_descriptor *type,
			void *value)
{
	if (type_is_int(type)) {
		if (type_bit_width(type) == 128) {
#if defined(CONFIG_ARCH_SUPPORTS_INT128)
			u_max val = get_unsigned_val(type, value);

			scnprintf(str, size, "0x%08x%08x%08x%08x",
				(u32)(val >> 96),
				(u32)(val >> 64),
				(u32)(val >> 32),
				(u32)(val));
#else
			WARN_ON(1);
#endif
		} else if (type_is_signed(type)) {
			scnprintf(str, size, "%lld",
				(s64)get_signed_val(type, value));
		} else {
			scnprintf(str, size, "%llu",
				(u64)get_unsigned_val(type, value));
		}
	}
}

static void ubsan_prologue(struct source_location *loc, const char *reason)
{
	current->in_ubsan++;

	pr_warn(CUT_HERE);

	pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name,
		loc->line & LINE_MASK, loc->column & COLUMN_MASK);

	kunit_fail_current_test("%s in %s", reason, loc->file_name);
}

static void ubsan_epilogue(void)
{
	dump_stack();
	pr_warn("---[ end trace ]---\n");

	current->in_ubsan--;

	check_panic_on_warn("UBSAN");
}

static void handle_overflow(struct overflow_data *data, void *lhs,
			void *rhs, char op)
{

	struct type_descriptor *type = data->type;
	char lhs_val_str[VALUE_LENGTH];
	char rhs_val_str[VALUE_LENGTH];

	if (suppress_report(&data->location))
		return;

	ubsan_prologue(&data->location, type_is_signed(type) ?
			"signed-integer-overflow" :
			"unsigned-integer-overflow");

	val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
	val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
	pr_err("%s %c %s cannot be represented in type %s\n",
		lhs_val_str,
		op,
		rhs_val_str,
		type->type_name);

	ubsan_epilogue();
}

void __ubsan_handle_add_overflow(void *data,
				void *lhs, void *rhs)
{

	handle_overflow(data, lhs, rhs, '+');
}
EXPORT_SYMBOL(__ubsan_handle_add_overflow);

void __ubsan_handle_sub_overflow(void *data,
				void *lhs, void *rhs)
{
	handle_overflow(data, lhs, rhs, '-');
}
EXPORT_SYMBOL(__ubsan_handle_sub_overflow);

void __ubsan_handle_mul_overflow(void *data,
				void *lhs, void *rhs)
{
	handle_overflow(data, lhs, rhs, '*');
}
EXPORT_SYMBOL(__ubsan_handle_mul_overflow);

void __ubsan_handle_negate_overflow(void *_data, void *old_val)
{
	struct overflow_data *data = _data;
	char old_val_str[VALUE_LENGTH];

	if (suppress_report(&data->location))
		return;

	ubsan_prologue(&data->location, "negation-overflow");

	val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);

	pr_err("negation of %s cannot be represented in type %s:\n",
		old_val_str, data->type->type_name);

	ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_negate_overflow);

void __ubsan_handle_implicit_conversion(void *_data, void *from_val, void *to_val)
{
	struct implicit_conversion_data *data = _data;
	char from_val_str[VALUE_LENGTH];
	char to_val_str[VALUE_LENGTH];

	if (suppress_report(&data->location))
		return;

	val_to_string(from_val_str, sizeof(from_val_str), data->from_type, from_val);
	val_to_string(to_val_str, sizeof(to_val_str), data->to_type, to_val);

	ubsan_prologue(&data->location, "implicit-conversion");

	pr_err("cannot represent %s value %s during %s %s, truncated to %s\n",
		data->from_type->type_name,
		from_val_str,
		type_check_kinds[data->type_check_kind],
		data->to_type->type_name,
		to_val_str);

	ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_implicit_conversion);

void __ubsan_handle_divrem_overflow(void *_data, void *lhs, void *rhs)
{
	struct overflow_data *data = _data;
	char rhs_val_str[VALUE_LENGTH];

	if (suppress_report(&data->location))
		return;

	ubsan_prologue(&data->location, "division-overflow");

	val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);

	if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1)
		pr_err("division of %s by -1 cannot be represented in type %s\n",
			rhs_val_str, data->type->type_name);
	else
		pr_err("division by zero\n");

	ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);

static void handle_null_ptr_deref(struct type_mismatch_data_common *data)
{
	if (suppress_report(data->location))
		return;

	ubsan_prologue(data->location, "null-ptr-deref");

	pr_err("%s null pointer of type %s\n",
		type_check_kinds[data->type_check_kind],
		data->type->type_name);

	ubsan_epilogue();
}

static void handle_misaligned_access(struct type_mismatch_data_common *data,
				unsigned long ptr)
{
	if (suppress_report(data->location))
		return;

	ubsan_prologue(data->location, "misaligned-access");

	pr_err("%s misaligned address %p for type %s\n",
		type_check_kinds[data->type_check_kind],
		(void *)ptr, data->type->type_name);
	pr_err("which requires %ld byte alignment\n", data->alignment);

	ubsan_epilogue();
}

static void handle_object_size_mismatch(struct type_mismatch_data_common *data,
					unsigned long ptr)
{
	if (suppress_report(data->location))
		return;

	ubsan_prologue(data->location, "object-size-mismatch");
	pr_err("%s address %p with insufficient space\n",
		type_check_kinds[data->type_check_kind],
		(void *) ptr);
	pr_err("for an object of type %s\n", data->type->type_name);
	ubsan_epilogue();
}

static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data,
				unsigned long ptr)
{
	unsigned long flags = user_access_save();

	if (!ptr)
		handle_null_ptr_deref(data);
	else if (data->alignment && !IS_ALIGNED(ptr, data->alignment))
		handle_misaligned_access(data, ptr);
	else
		handle_object_size_mismatch(data, ptr);

	user_access_restore(flags);
}

void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
				void *ptr)
{
	struct type_mismatch_data_common common_data = {
		.location = &data->location,
		.type = data->type,
		.alignment = data->alignment,
		.type_check_kind = data->type_check_kind
	};

	ubsan_type_mismatch_common(&common_data, (unsigned long)ptr);
}
EXPORT_SYMBOL(__ubsan_handle_type_mismatch);

void __ubsan_handle_type_mismatch_v1(void *_data, void *ptr)
{
	struct type_mismatch_data_v1 *data = _data;
	struct type_mismatch_data_common common_data = {
		.location = &data->location,
		.type = data->type,
		.alignment = 1UL << data->log_alignment,
		.type_check_kind = data->type_check_kind
	};

	ubsan_type_mismatch_common(&common_data, (unsigned long)ptr);
}
EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);

void __ubsan_handle_out_of_bounds(void *_data, void *index)
{
	struct out_of_bounds_data *data = _data;
	char index_str[VALUE_LENGTH];

	if (suppress_report(&data->location))
		return;

	ubsan_prologue(&data->location, "array-index-out-of-bounds");

	val_to_string(index_str, sizeof(index_str), data->index_type, index);
	pr_err("index %s is out of range for type %s\n", index_str,
		data->array_type->type_name);
	ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);

void __ubsan_handle_shift_out_of_bounds(void *_data, void *lhs, void *rhs)
{
	struct shift_out_of_bounds_data *data = _data;
	struct type_descriptor *rhs_type = data->rhs_type;
	struct type_descriptor *lhs_type = data->lhs_type;
	char rhs_str[VALUE_LENGTH];
	char lhs_str[VALUE_LENGTH];
	unsigned long ua_flags = user_access_save();

	if (suppress_report(&data->location))
		goto out;

	ubsan_prologue(&data->location, "shift-out-of-bounds");

	val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
	val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);

	if (val_is_negative(rhs_type, rhs))
		pr_err("shift exponent %s is negative\n", rhs_str);

	else if (get_unsigned_val(rhs_type, rhs) >=
		type_bit_width(lhs_type))
		pr_err("shift exponent %s is too large for %u-bit type %s\n",
			rhs_str,
			type_bit_width(lhs_type),
			lhs_type->type_name);
	else if (val_is_negative(lhs_type, lhs))
		pr_err("left shift of negative value %s\n",
			lhs_str);
	else
		pr_err("left shift of %s by %s places cannot be"
			" represented in type %s\n",
			lhs_str, rhs_str,
			lhs_type->type_name);

	ubsan_epilogue();
out:
	user_access_restore(ua_flags);
}
EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);


void __ubsan_handle_builtin_unreachable(void *_data)
{
	struct unreachable_data *data = _data;
	ubsan_prologue(&data->location, "unreachable");
	pr_err("calling __builtin_unreachable()\n");
	ubsan_epilogue();
	panic("can't return from __builtin_unreachable()");
}
EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);

void __ubsan_handle_load_invalid_value(void *_data, void *val)
{
	struct invalid_value_data *data = _data;
	char val_str[VALUE_LENGTH];
	unsigned long ua_flags = user_access_save();

	if (suppress_report(&data->location))
		goto out;

	ubsan_prologue(&data->location, "invalid-load");

	val_to_string(val_str, sizeof(val_str), data->type, val);

	pr_err("load of value %s is not a valid value for type %s\n",
		val_str, data->type->type_name);

	ubsan_epilogue();
out:
	user_access_restore(ua_flags);
}
EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);

void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
					 unsigned long align,
					 unsigned long offset)
{
	struct alignment_assumption_data *data = _data;
	unsigned long real_ptr;

	if (suppress_report(&data->location))
		return;

	ubsan_prologue(&data->location, "alignment-assumption");

	if (offset)
		pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed",
		       align, offset, data->type->type_name);
	else
		pr_err("assumption of %lu byte alignment for pointer of type %s failed",
		       align, data->type->type_name);

	real_ptr = ptr - offset;
	pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes",
	       offset ? "offset " : "", BIT(real_ptr ? __ffs(real_ptr) : 0),
	       real_ptr & (align - 1));

	ubsan_epilogue();
}
EXPORT_SYMBOL(__ubsan_handle_alignment_assumption);

#endif /* !CONFIG_UBSAN_TRAP */
Commit	Line	Data
	1	// SPDX-License-Identifier: GPL-2.0-only
	2	/*
	3	* UBSAN error reporting functions
	4	*
	5	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	6	* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
	7	*/
	8
	9	#include <linux/bitops.h>
	10	#include <linux/bug.h>
	11	#include <linux/ctype.h>
	12	#include <linux/init.h>
	13	#include <linux/kernel.h>
	14	#include <linux/types.h>
	15	#include <linux/sched.h>
	16	#include <linux/uaccess.h>
	17	#include <linux/ubsan.h>
	18	#include <kunit/test-bug.h>
	19
	20	#include "ubsan.h"
	21
	22	#if defined(CONFIG_UBSAN_TRAP) \|\| defined(CONFIG_UBSAN_KVM_EL2)
	23	/*
	24	* Only include matches for UBSAN checks that are actually compiled in.
	25	* The mappings of struct SanitizerKind (the -fsanitize=xxx args) to
	26	* enum SanitizerHandler (the traps) in Clang is in clang/lib/CodeGen/.
	27	*/
	28	const char *report_ubsan_failure(u32 check_type)
	29	{
	30	switch (check_type) {
	31	#ifdef CONFIG_UBSAN_BOUNDS
	32	/*
	33	* SanitizerKind::ArrayBounds and SanitizerKind::LocalBounds
	34	* emit SanitizerHandler::OutOfBounds.
	35	*/
	36	case ubsan_out_of_bounds:
	37	return "UBSAN: array index out of bounds";
	38	#endif
	39	#ifdef CONFIG_UBSAN_SHIFT
	40	/*
	41	* SanitizerKind::ShiftBase and SanitizerKind::ShiftExponent
	42	* emit SanitizerHandler::ShiftOutOfBounds.
	43	*/
	44	case ubsan_shift_out_of_bounds:
	45	return "UBSAN: shift out of bounds";
	46	#endif
	47	#if defined(CONFIG_UBSAN_DIV_ZERO) \|\| defined(CONFIG_UBSAN_INTEGER_WRAP)
	48	/*
	49	* SanitizerKind::IntegerDivideByZero and
	50	* SanitizerKind::SignedIntegerOverflow emit
	51	* SanitizerHandler::DivremOverflow.
	52	*/
	53	case ubsan_divrem_overflow:
	54	return "UBSAN: divide/remainder overflow";
	55	#endif
	56	#ifdef CONFIG_UBSAN_UNREACHABLE
	57	/*
	58	* SanitizerKind::Unreachable emits
	59	* SanitizerHandler::BuiltinUnreachable.
	60	*/
	61	case ubsan_builtin_unreachable:
	62	return "UBSAN: unreachable code";
	63	#endif
	64	#if defined(CONFIG_UBSAN_BOOL) \|\| defined(CONFIG_UBSAN_ENUM)
	65	/*
	66	* SanitizerKind::Bool and SanitizerKind::Enum emit
	67	* SanitizerHandler::LoadInvalidValue.
	68	*/
	69	case ubsan_load_invalid_value:
	70	return "UBSAN: loading invalid value";
	71	#endif
	72	#ifdef CONFIG_UBSAN_ALIGNMENT
	73	/*
	74	* SanitizerKind::Alignment emits SanitizerHandler::TypeMismatch
	75	* or SanitizerHandler::AlignmentAssumption.
	76	*/
	77	case ubsan_alignment_assumption:
	78	return "UBSAN: alignment assumption";
	79	case ubsan_type_mismatch:
	80	return "UBSAN: type mismatch";
	81	#endif
	82	#ifdef CONFIG_UBSAN_INTEGER_WRAP
	83	/*
	84	* SanitizerKind::SignedIntegerOverflow emits
	85	* SanitizerHandler::AddOverflow, SanitizerHandler::SubOverflow,
	86	* or SanitizerHandler::MulOverflow.
	87	*/
	88	case ubsan_add_overflow:
	89	return "UBSAN: integer addition overflow";
	90	case ubsan_sub_overflow:
	91	return "UBSAN: integer subtraction overflow";
	92	case ubsan_mul_overflow:
	93	return "UBSAN: integer multiplication overflow";
	94	#endif
	95	default:
	96	return "UBSAN: unrecognized failure code";
	97	}
	98	}
	99
	100	#endif
	101
	102	#ifndef CONFIG_UBSAN_TRAP
	103	static const char * const type_check_kinds[] = {
	104	"load of",
	105	"store to",
	106	"reference binding to",
	107	"member access within",
	108	"member call on",
	109	"constructor call on",
	110	"downcast of",
	111	"downcast of"
	112	};
	113
	114	#define REPORTED_BIT 31
	115
	116	#if (BITS_PER_LONG == 64) && defined(__BIG_ENDIAN)
	117	#define COLUMN_MASK (~(1U << REPORTED_BIT))
	118	#define LINE_MASK (~0U)
	119	#else
	120	#define COLUMN_MASK (~0U)
	121	#define LINE_MASK (~(1U << REPORTED_BIT))
	122	#endif
	123
	124	#define VALUE_LENGTH 40
	125
	126	static bool was_reported(struct source_location *location)
	127	{
	128	return test_and_set_bit(REPORTED_BIT, &location->reported);
	129	}
	130
	131	static bool suppress_report(struct source_location *loc)
	132	{
	133	return current->in_ubsan \|\| was_reported(loc);
	134	}
	135
	136	static bool type_is_int(struct type_descriptor *type)
	137	{
	138	return type->type_kind == type_kind_int;
	139	}
	140
	141	static bool type_is_signed(struct type_descriptor *type)
	142	{
	143	WARN_ON(!type_is_int(type));
	144	return type->type_info & 1;
	145	}
	146
	147	static unsigned type_bit_width(struct type_descriptor *type)
	148	{
	149	return 1 << (type->type_info >> 1);
	150	}
	151
	152	static bool is_inline_int(struct type_descriptor *type)
	153	{
	154	unsigned inline_bits = sizeof(unsigned long)*8;
	155	unsigned bits = type_bit_width(type);
	156
	157	WARN_ON(!type_is_int(type));
	158
	159	return bits <= inline_bits;
	160	}
	161
	162	static s_max get_signed_val(struct type_descriptor type, void val)
	163	{
	164	if (is_inline_int(type)) {
	165	unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
	166	unsigned long ulong_val = (unsigned long)val;
	167
	168	return ((s_max)ulong_val) << extra_bits >> extra_bits;
	169	}
	170
	171	if (type_bit_width(type) == 64)
	172	return (s64 )val;
	173
	174	return (s_max )val;
	175	}
	176
	177	static bool val_is_negative(struct type_descriptor type, void val)
	178	{
	179	return type_is_signed(type) && get_signed_val(type, val) < 0;
	180	}
	181
	182	static u_max get_unsigned_val(struct type_descriptor type, void val)
	183	{
	184	if (is_inline_int(type))
	185	return (unsigned long)val;
	186
	187	if (type_bit_width(type) == 64)
	188	return (u64 )val;
	189
	190	return (u_max )val;
	191	}
	192
	193	static void val_to_string(char str, size_t size, struct type_descriptor type,
	194	void *value)
	195	{
	196	if (type_is_int(type)) {
	197	if (type_bit_width(type) == 128) {
	198	#if defined(CONFIG_ARCH_SUPPORTS_INT128)
	199	u_max val = get_unsigned_val(type, value);
	200
	201	scnprintf(str, size, "0x%08x%08x%08x%08x",
	202	(u32)(val >> 96),
	203	(u32)(val >> 64),
	204	(u32)(val >> 32),
	205	(u32)(val));
	206	#else
	207	WARN_ON(1);
	208	#endif
	209	} else if (type_is_signed(type)) {
	210	scnprintf(str, size, "%lld",
	211	(s64)get_signed_val(type, value));
	212	} else {
	213	scnprintf(str, size, "%llu",
	214	(u64)get_unsigned_val(type, value));
	215	}
	216	}
	217	}
	218
	219	static void ubsan_prologue(struct source_location loc, const char reason)
	220	{
	221	current->in_ubsan++;
	222
	223	pr_warn(CUT_HERE);
	224
	225	pr_err("UBSAN: %s in %s:%d:%d\n", reason, loc->file_name,
	226	loc->line & LINE_MASK, loc->column & COLUMN_MASK);
	227
	228	kunit_fail_current_test("%s in %s", reason, loc->file_name);
	229	}
	230
	231	static void ubsan_epilogue(void)
	232	{
	233	dump_stack();
	234	pr_warn("---[ end trace ]---\n");
	235
	236	current->in_ubsan--;
	237
	238	check_panic_on_warn("UBSAN");
	239	}
	240
	241	static void handle_overflow(struct overflow_data data, void lhs,
	242	void *rhs, char op)
	243	{
	244
	245	struct type_descriptor *type = data->type;
	246	char lhs_val_str[VALUE_LENGTH];
	247	char rhs_val_str[VALUE_LENGTH];
	248
	249	if (suppress_report(&data->location))
	250	return;
	251
	252	ubsan_prologue(&data->location, type_is_signed(type) ?
	253	"signed-integer-overflow" :
	254	"unsigned-integer-overflow");
	255
	256	val_to_string(lhs_val_str, sizeof(lhs_val_str), type, lhs);
	257	val_to_string(rhs_val_str, sizeof(rhs_val_str), type, rhs);
	258	pr_err("%s %c %s cannot be represented in type %s\n",
	259	lhs_val_str,
	260	op,
	261	rhs_val_str,
	262	type->type_name);
	263
	264	ubsan_epilogue();
	265	}
	266
	267	void __ubsan_handle_add_overflow(void *data,
	268	void lhs, void rhs)
	269	{
	270
	271	handle_overflow(data, lhs, rhs, '+');
	272	}
	273	EXPORT_SYMBOL(__ubsan_handle_add_overflow);
	274
	275	void __ubsan_handle_sub_overflow(void *data,
	276	void lhs, void rhs)
	277	{
	278	handle_overflow(data, lhs, rhs, '-');
	279	}
	280	EXPORT_SYMBOL(__ubsan_handle_sub_overflow);
	281
	282	void __ubsan_handle_mul_overflow(void *data,
	283	void lhs, void rhs)
	284	{
	285	handle_overflow(data, lhs, rhs, '*');
	286	}
	287	EXPORT_SYMBOL(__ubsan_handle_mul_overflow);
	288
	289	void __ubsan_handle_negate_overflow(void _data, void old_val)
	290	{
	291	struct overflow_data *data = _data;
	292	char old_val_str[VALUE_LENGTH];
	293
	294	if (suppress_report(&data->location))
	295	return;
	296
	297	ubsan_prologue(&data->location, "negation-overflow");
	298
	299	val_to_string(old_val_str, sizeof(old_val_str), data->type, old_val);
	300
	301	pr_err("negation of %s cannot be represented in type %s:\n",
	302	old_val_str, data->type->type_name);
	303
	304	ubsan_epilogue();
	305	}
	306	EXPORT_SYMBOL(__ubsan_handle_negate_overflow);
	307
	308	void __ubsan_handle_implicit_conversion(void _data, void from_val, void *to_val)
	309	{
	310	struct implicit_conversion_data *data = _data;
	311	char from_val_str[VALUE_LENGTH];
	312	char to_val_str[VALUE_LENGTH];
	313
	314	if (suppress_report(&data->location))
	315	return;
	316
	317	val_to_string(from_val_str, sizeof(from_val_str), data->from_type, from_val);
	318	val_to_string(to_val_str, sizeof(to_val_str), data->to_type, to_val);
	319
	320	ubsan_prologue(&data->location, "implicit-conversion");
	321
	322	pr_err("cannot represent %s value %s during %s %s, truncated to %s\n",
	323	data->from_type->type_name,
	324	from_val_str,
	325	type_check_kinds[data->type_check_kind],
	326	data->to_type->type_name,
	327	to_val_str);
	328
	329	ubsan_epilogue();
	330	}
	331	EXPORT_SYMBOL(__ubsan_handle_implicit_conversion);
	332
	333	void __ubsan_handle_divrem_overflow(void _data, void lhs, void *rhs)
	334	{
	335	struct overflow_data *data = _data;
	336	char rhs_val_str[VALUE_LENGTH];
	337
	338	if (suppress_report(&data->location))
	339	return;
	340
	341	ubsan_prologue(&data->location, "division-overflow");
	342
	343	val_to_string(rhs_val_str, sizeof(rhs_val_str), data->type, rhs);
	344
	345	if (type_is_signed(data->type) && get_signed_val(data->type, rhs) == -1)
	346	pr_err("division of %s by -1 cannot be represented in type %s\n",
	347	rhs_val_str, data->type->type_name);
	348	else
	349	pr_err("division by zero\n");
	350
	351	ubsan_epilogue();
	352	}
	353	EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);
	354
	355	static void handle_null_ptr_deref(struct type_mismatch_data_common *data)
	356	{
	357	if (suppress_report(data->location))
	358	return;
	359
	360	ubsan_prologue(data->location, "null-ptr-deref");
	361
	362	pr_err("%s null pointer of type %s\n",
	363	type_check_kinds[data->type_check_kind],
	364	data->type->type_name);
	365
	366	ubsan_epilogue();
	367	}
	368
	369	static void handle_misaligned_access(struct type_mismatch_data_common *data,
	370	unsigned long ptr)
	371	{
	372	if (suppress_report(data->location))
	373	return;
	374
	375	ubsan_prologue(data->location, "misaligned-access");
	376
	377	pr_err("%s misaligned address %p for type %s\n",
	378	type_check_kinds[data->type_check_kind],
	379	(void *)ptr, data->type->type_name);
	380	pr_err("which requires %ld byte alignment\n", data->alignment);
	381
	382	ubsan_epilogue();
	383	}
	384
	385	static void handle_object_size_mismatch(struct type_mismatch_data_common *data,
	386	unsigned long ptr)
	387	{
	388	if (suppress_report(data->location))
	389	return;
	390
	391	ubsan_prologue(data->location, "object-size-mismatch");
	392	pr_err("%s address %p with insufficient space\n",
	393	type_check_kinds[data->type_check_kind],
	394	(void *) ptr);
	395	pr_err("for an object of type %s\n", data->type->type_name);
	396	ubsan_epilogue();
	397	}
	398
	399	static void ubsan_type_mismatch_common(struct type_mismatch_data_common *data,
	400	unsigned long ptr)
	401	{
	402	unsigned long flags = user_access_save();
	403
	404	if (!ptr)
	405	handle_null_ptr_deref(data);
	406	else if (data->alignment && !IS_ALIGNED(ptr, data->alignment))
	407	handle_misaligned_access(data, ptr);
	408	else
	409	handle_object_size_mismatch(data, ptr);
	410
	411	user_access_restore(flags);
	412	}
	413
	414	void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
	415	void *ptr)
	416	{
	417	struct type_mismatch_data_common common_data = {
	418	.location = &data->location,
	419	.type = data->type,
	420	.alignment = data->alignment,
	421	.type_check_kind = data->type_check_kind
	422	};
	423
	424	ubsan_type_mismatch_common(&common_data, (unsigned long)ptr);
	425	}
	426	EXPORT_SYMBOL(__ubsan_handle_type_mismatch);
	427
	428	void __ubsan_handle_type_mismatch_v1(void _data, void ptr)
	429	{
	430	struct type_mismatch_data_v1 *data = _data;
	431	struct type_mismatch_data_common common_data = {
	432	.location = &data->location,
	433	.type = data->type,
	434	.alignment = 1UL << data->log_alignment,
	435	.type_check_kind = data->type_check_kind
	436	};
	437
	438	ubsan_type_mismatch_common(&common_data, (unsigned long)ptr);
	439	}
	440	EXPORT_SYMBOL(__ubsan_handle_type_mismatch_v1);
	441
	442	void __ubsan_handle_out_of_bounds(void _data, void index)
	443	{
	444	struct out_of_bounds_data *data = _data;
	445	char index_str[VALUE_LENGTH];
	446
	447	if (suppress_report(&data->location))
	448	return;
	449
	450	ubsan_prologue(&data->location, "array-index-out-of-bounds");
	451
	452	val_to_string(index_str, sizeof(index_str), data->index_type, index);
	453	pr_err("index %s is out of range for type %s\n", index_str,
	454	data->array_type->type_name);
	455	ubsan_epilogue();
	456	}
	457	EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);
	458
	459	void __ubsan_handle_shift_out_of_bounds(void _data, void lhs, void *rhs)
	460	{
	461	struct shift_out_of_bounds_data *data = _data;
	462	struct type_descriptor *rhs_type = data->rhs_type;
	463	struct type_descriptor *lhs_type = data->lhs_type;
	464	char rhs_str[VALUE_LENGTH];
	465	char lhs_str[VALUE_LENGTH];
	466	unsigned long ua_flags = user_access_save();
	467
	468	if (suppress_report(&data->location))
	469	goto out;
	470
	471	ubsan_prologue(&data->location, "shift-out-of-bounds");
	472
	473	val_to_string(rhs_str, sizeof(rhs_str), rhs_type, rhs);
	474	val_to_string(lhs_str, sizeof(lhs_str), lhs_type, lhs);
	475
	476	if (val_is_negative(rhs_type, rhs))
	477	pr_err("shift exponent %s is negative\n", rhs_str);
	478
	479	else if (get_unsigned_val(rhs_type, rhs) >=
	480	type_bit_width(lhs_type))
	481	pr_err("shift exponent %s is too large for %u-bit type %s\n",
	482	rhs_str,
	483	type_bit_width(lhs_type),
	484	lhs_type->type_name);
	485	else if (val_is_negative(lhs_type, lhs))
	486	pr_err("left shift of negative value %s\n",
	487	lhs_str);
	488	else
	489	pr_err("left shift of %s by %s places cannot be"
	490	" represented in type %s\n",
	491	lhs_str, rhs_str,
	492	lhs_type->type_name);
	493
	494	ubsan_epilogue();
	495	out:
	496	user_access_restore(ua_flags);
	497	}
	498	EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);
	499
	500
	501	void __ubsan_handle_builtin_unreachable(void *_data)
	502	{
	503	struct unreachable_data *data = _data;
	504	ubsan_prologue(&data->location, "unreachable");
	505	pr_err("calling __builtin_unreachable()\n");
	506	ubsan_epilogue();
	507	panic("can't return from __builtin_unreachable()");
	508	}
	509	EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);
	510
	511	void __ubsan_handle_load_invalid_value(void _data, void val)
	512	{
	513	struct invalid_value_data *data = _data;
	514	char val_str[VALUE_LENGTH];
	515	unsigned long ua_flags = user_access_save();
	516
	517	if (suppress_report(&data->location))
	518	goto out;
	519
	520	ubsan_prologue(&data->location, "invalid-load");
	521
	522	val_to_string(val_str, sizeof(val_str), data->type, val);
	523
	524	pr_err("load of value %s is not a valid value for type %s\n",
	525	val_str, data->type->type_name);
	526
	527	ubsan_epilogue();
	528	out:
	529	user_access_restore(ua_flags);
	530	}
	531	EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
	532
	533	void __ubsan_handle_alignment_assumption(void *_data, unsigned long ptr,
	534	unsigned long align,
	535	unsigned long offset)
	536	{
	537	struct alignment_assumption_data *data = _data;
	538	unsigned long real_ptr;
	539
	540	if (suppress_report(&data->location))
	541	return;
	542
	543	ubsan_prologue(&data->location, "alignment-assumption");
	544
	545	if (offset)
	546	pr_err("assumption of %lu byte alignment (with offset of %lu byte) for pointer of type %s failed",
	547	align, offset, data->type->type_name);
	548	else
	549	pr_err("assumption of %lu byte alignment for pointer of type %s failed",
	550	align, data->type->type_name);
	551
	552	real_ptr = ptr - offset;
	553	pr_err("%saddress is %lu aligned, misalignment offset is %lu bytes",
	554	offset ? "offset " : "", BIT(real_ptr ? __ffs(real_ptr) : 0),
	555	real_ptr & (align - 1));
	556
	557	ubsan_epilogue();
	558	}
	559	EXPORT_SYMBOL(__ubsan_handle_alignment_assumption);
	560
	561	#endif /* !CONFIG_UBSAN_TRAP */