lib/ubsan.c - linux/kernel/git/gregkh/tty - Git at Google

 /*
  * UBSAN error reporting functions
  *
  * Copyright (c) 2014 Samsung Electronics Co., Ltd.
  * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  */

 #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 "ubsan.h"

 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"
 };

 #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 void print_source_location(const char *prefix,
 				struct source_location *loc)
 {
 	pr_err("%s %s:%d:%d\n", prefix, loc->file_name,
 		loc->line & LINE_MASK, loc->column & COLUMN_MASK);
 }

 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, unsigned long val)
 {
 	if (is_inline_int(type)) {
 		unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
 		return ((s_max)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, unsigned long val)
 {
 	return type_is_signed(type) && get_signed_val(type, val) < 0;
 }

 static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val)
 {
 	if (is_inline_int(type))
 		return 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,
 	unsigned long value)
 {
 	if (type_is_int(type)) {
 		if (type_bit_width(type) == 128) {
 #if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_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 bool location_is_valid(struct source_location *loc)
 {
 	return loc->file_name != NULL;
 }

 static DEFINE_SPINLOCK(report_lock);

 static void ubsan_prologue(struct source_location *location,
 			unsigned long *flags)
 {
 	current->in_ubsan++;
 	spin_lock_irqsave(&report_lock, *flags);

 	pr_err("========================================"
 		"========================================\n");
 	print_source_location("UBSAN: Undefined behaviour in", location);
 }

 static void ubsan_epilogue(unsigned long *flags)
 {
 	dump_stack();
 	pr_err("========================================"
 		"========================================\n");
 	spin_unlock_irqrestore(&report_lock, *flags);
 	current->in_ubsan--;
 }

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

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

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

 	ubsan_prologue(&data->location, &flags);

 	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 integer overflow:\n",
 		type_is_signed(type) ? "signed" : "unsigned");
 	pr_err("%s %c %s cannot be represented in type %s\n",
 		lhs_val_str,
 		op,
 		rhs_val_str,
 		type->type_name);

 	ubsan_epilogue(&flags);
 }

 void __ubsan_handle_add_overflow(struct overflow_data *data,
 				unsigned long lhs,
 				unsigned long rhs)
 {

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

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

 void __ubsan_handle_mul_overflow(struct overflow_data *data,
 				unsigned long lhs,
 				unsigned long rhs)
 {
 	handle_overflow(data, lhs, rhs, '*');
 }
 EXPORT_SYMBOL(__ubsan_handle_mul_overflow);

 void __ubsan_handle_negate_overflow(struct overflow_data *data,
 				unsigned long old_val)
 {
 	unsigned long flags;
 	char old_val_str[VALUE_LENGTH];

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

 	ubsan_prologue(&data->location, &flags);

 	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(&flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_negate_overflow);


 void __ubsan_handle_divrem_overflow(struct overflow_data *data,
 				unsigned long lhs,
 				unsigned long rhs)
 {
 	unsigned long flags;
 	char rhs_val_str[VALUE_LENGTH];

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

 	ubsan_prologue(&data->location, &flags);

 	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(&flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);

 static void handle_null_ptr_deref(struct type_mismatch_data *data)
 {
 	unsigned long flags;

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

 	ubsan_prologue(&data->location, &flags);

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

 	ubsan_epilogue(&flags);
 }

 static void handle_missaligned_access(struct type_mismatch_data *data,
 				unsigned long ptr)
 {
 	unsigned long flags;

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

 	ubsan_prologue(&data->location, &flags);

 	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(&flags);
 }

 static void handle_object_size_mismatch(struct type_mismatch_data *data,
 					unsigned long ptr)
 {
 	unsigned long flags;

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

 	ubsan_prologue(&data->location, &flags);
 	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(&flags);
 }

 void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
 				unsigned long ptr)
 {

 	if (!ptr)
 		handle_null_ptr_deref(data);
 	else if (data->alignment && !IS_ALIGNED(ptr, data->alignment))
 		handle_missaligned_access(data, ptr);
 	else
 		handle_object_size_mismatch(data, ptr);
 }
 EXPORT_SYMBOL(__ubsan_handle_type_mismatch);

 void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
 {
 	unsigned long flags;

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

 	ubsan_prologue(&data->location, &flags);

 	pr_err("null pointer returned from function declared to never return null\n");

 	if (location_is_valid(&data->attr_location))
 		print_source_location("returns_nonnull attribute specified in",
 				&data->attr_location);

 	ubsan_epilogue(&flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_nonnull_return);

 void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
 					unsigned long bound)
 {
 	unsigned long flags;
 	char bound_str[VALUE_LENGTH];

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

 	ubsan_prologue(&data->location, &flags);

 	val_to_string(bound_str, sizeof(bound_str), data->type, bound);
 	pr_err("variable length array bound value %s <= 0\n", bound_str);

 	ubsan_epilogue(&flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);

 void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data,
 				unsigned long index)
 {
 	unsigned long flags;
 	char index_str[VALUE_LENGTH];

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

 	ubsan_prologue(&data->location, &flags);

 	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(&flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);

 void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
 					unsigned long lhs, unsigned long rhs)
 {
 	unsigned long flags;
 	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];

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

 	ubsan_prologue(&data->location, &flags);

 	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(&flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);


 void __noreturn
 __ubsan_handle_builtin_unreachable(struct unreachable_data *data)
 {
 	unsigned long flags;

 	ubsan_prologue(&data->location, &flags);
 	pr_err("calling __builtin_unreachable()\n");
 	ubsan_epilogue(&flags);
 	panic("can't return from __builtin_unreachable()");
 }
 EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);

 void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
 				unsigned long val)
 {
 	unsigned long flags;
 	char val_str[VALUE_LENGTH];

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

 	ubsan_prologue(&data->location, &flags);

 	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(&flags);
 }
 EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);
	/*
	* UBSAN error reporting functions
	*
	* Copyright (c) 2014 Samsung Electronics Co., Ltd.
	* Author: Andrey Ryabinin <ryabinin.a.a@gmail.com>
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	*/

	#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 "ubsan.h"

	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"
	};

	#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 void print_source_location(const char *prefix,
	struct source_location *loc)
	{
	pr_err("%s %s:%d:%d\n", prefix, loc->file_name,
	loc->line & LINE_MASK, loc->column & COLUMN_MASK);
	}

	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, unsigned long val)
	{
	if (is_inline_int(type)) {
	unsigned extra_bits = sizeof(s_max)*8 - type_bit_width(type);
	return ((s_max)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, unsigned long val)
	{
	return type_is_signed(type) && get_signed_val(type, val) < 0;
	}

	static u_max get_unsigned_val(struct type_descriptor *type, unsigned long val)
	{
	if (is_inline_int(type))
	return 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,
	unsigned long value)
	{
	if (type_is_int(type)) {
	if (type_bit_width(type) == 128) {
	#if defined(CONFIG_ARCH_SUPPORTS_INT128) && defined(__SIZEOF_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 bool location_is_valid(struct source_location *loc)
	{
	return loc->file_name != NULL;
	}

	static DEFINE_SPINLOCK(report_lock);

	static void ubsan_prologue(struct source_location *location,
	unsigned long *flags)
	{
	current->in_ubsan++;
	spin_lock_irqsave(&report_lock, *flags);

	pr_err("========================================"
	"========================================\n");
	print_source_location("UBSAN: Undefined behaviour in", location);
	}

	static void ubsan_epilogue(unsigned long *flags)
	{
	dump_stack();
	pr_err("========================================"
	"========================================\n");
	spin_unlock_irqrestore(&report_lock, *flags);
	current->in_ubsan--;
	}

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

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

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

	ubsan_prologue(&data->location, &flags);

	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 integer overflow:\n",
	type_is_signed(type) ? "signed" : "unsigned");
	pr_err("%s %c %s cannot be represented in type %s\n",
	lhs_val_str,
	op,
	rhs_val_str,
	type->type_name);

	ubsan_epilogue(&flags);
	}

	void __ubsan_handle_add_overflow(struct overflow_data *data,
	unsigned long lhs,
	unsigned long rhs)
	{

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

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

	void __ubsan_handle_mul_overflow(struct overflow_data *data,
	unsigned long lhs,
	unsigned long rhs)
	{
	handle_overflow(data, lhs, rhs, '*');
	}
	EXPORT_SYMBOL(__ubsan_handle_mul_overflow);

	void __ubsan_handle_negate_overflow(struct overflow_data *data,
	unsigned long old_val)
	{
	unsigned long flags;
	char old_val_str[VALUE_LENGTH];

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

	ubsan_prologue(&data->location, &flags);

	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(&flags);
	}
	EXPORT_SYMBOL(__ubsan_handle_negate_overflow);


	void __ubsan_handle_divrem_overflow(struct overflow_data *data,
	unsigned long lhs,
	unsigned long rhs)
	{
	unsigned long flags;
	char rhs_val_str[VALUE_LENGTH];

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

	ubsan_prologue(&data->location, &flags);

	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(&flags);
	}
	EXPORT_SYMBOL(__ubsan_handle_divrem_overflow);

	static void handle_null_ptr_deref(struct type_mismatch_data *data)
	{
	unsigned long flags;

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

	ubsan_prologue(&data->location, &flags);

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

	ubsan_epilogue(&flags);
	}

	static void handle_missaligned_access(struct type_mismatch_data *data,
	unsigned long ptr)
	{
	unsigned long flags;

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

	ubsan_prologue(&data->location, &flags);

	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(&flags);
	}

	static void handle_object_size_mismatch(struct type_mismatch_data *data,
	unsigned long ptr)
	{
	unsigned long flags;

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

	ubsan_prologue(&data->location, &flags);
	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(&flags);
	}

	void __ubsan_handle_type_mismatch(struct type_mismatch_data *data,
	unsigned long ptr)
	{

	if (!ptr)
	handle_null_ptr_deref(data);
	else if (data->alignment && !IS_ALIGNED(ptr, data->alignment))
	handle_missaligned_access(data, ptr);
	else
	handle_object_size_mismatch(data, ptr);
	}
	EXPORT_SYMBOL(__ubsan_handle_type_mismatch);

	void __ubsan_handle_nonnull_return(struct nonnull_return_data *data)
	{
	unsigned long flags;

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

	ubsan_prologue(&data->location, &flags);

	pr_err("null pointer returned from function declared to never return null\n");

	if (location_is_valid(&data->attr_location))
	print_source_location("returns_nonnull attribute specified in",
	&data->attr_location);

	ubsan_epilogue(&flags);
	}
	EXPORT_SYMBOL(__ubsan_handle_nonnull_return);

	void __ubsan_handle_vla_bound_not_positive(struct vla_bound_data *data,
	unsigned long bound)
	{
	unsigned long flags;
	char bound_str[VALUE_LENGTH];

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

	ubsan_prologue(&data->location, &flags);

	val_to_string(bound_str, sizeof(bound_str), data->type, bound);
	pr_err("variable length array bound value %s <= 0\n", bound_str);

	ubsan_epilogue(&flags);
	}
	EXPORT_SYMBOL(__ubsan_handle_vla_bound_not_positive);

	void __ubsan_handle_out_of_bounds(struct out_of_bounds_data *data,
	unsigned long index)
	{
	unsigned long flags;
	char index_str[VALUE_LENGTH];

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

	ubsan_prologue(&data->location, &flags);

	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(&flags);
	}
	EXPORT_SYMBOL(__ubsan_handle_out_of_bounds);

	void __ubsan_handle_shift_out_of_bounds(struct shift_out_of_bounds_data *data,
	unsigned long lhs, unsigned long rhs)
	{
	unsigned long flags;
	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];

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

	ubsan_prologue(&data->location, &flags);

	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(&flags);
	}
	EXPORT_SYMBOL(__ubsan_handle_shift_out_of_bounds);


	void __noreturn
	__ubsan_handle_builtin_unreachable(struct unreachable_data *data)
	{
	unsigned long flags;

	ubsan_prologue(&data->location, &flags);
	pr_err("calling __builtin_unreachable()\n");
	ubsan_epilogue(&flags);
	panic("can't return from __builtin_unreachable()");
	}
	EXPORT_SYMBOL(__ubsan_handle_builtin_unreachable);

	void __ubsan_handle_load_invalid_value(struct invalid_value_data *data,
	unsigned long val)
	{
	unsigned long flags;
	char val_str[VALUE_LENGTH];

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

	ubsan_prologue(&data->location, &flags);

	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(&flags);
	}
	EXPORT_SYMBOL(__ubsan_handle_load_invalid_value);