linux-hardened/include/asm-generic/bitops/instrumented-non-atomic.h
Daniel Axtens 81d2c6f819 kasan: support instrumented bitops combined with generic bitops
Currently bitops-instrumented.h assumes that the architecture provides
atomic, non-atomic and locking bitops (e.g. both set_bit and __set_bit).
This is true on x86 and s390, but is not always true: there is a
generic bitops/non-atomic.h header that provides generic non-atomic
operations, and also a generic bitops/lock.h for locking operations.

powerpc uses the generic non-atomic version, so it does not have it's
own e.g. __set_bit that could be renamed arch___set_bit.

Split up bitops-instrumented.h to mirror the atomic/non-atomic/lock
split. This allows arches to only include the headers where they
have arch-specific versions to rename. Update x86 and s390.

(The generic operations are automatically instrumented because they're
written in C, not asm.)

Suggested-by: Christophe Leroy <christophe.leroy@c-s.fr>
Reviewed-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Daniel Axtens <dja@axtens.net>
Acked-by: Marco Elver <elver@google.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820024941.12640-1-dja@axtens.net
2019-11-07 13:15:39 +11:00

114 lines
3.4 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* This file provides wrappers with sanitizer instrumentation for non-atomic
* bit operations.
*
* To use this functionality, an arch's bitops.h file needs to define each of
* the below bit operations with an arch_ prefix (e.g. arch_set_bit(),
* arch___set_bit(), etc.).
*/
#ifndef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
#define _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
#include <linux/kasan-checks.h>
/**
* __set_bit - Set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* Unlike set_bit(), this function is non-atomic. If it is called on the same
* region of memory concurrently, the effect may be that only one operation
* succeeds.
*/
static inline void __set_bit(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
arch___set_bit(nr, addr);
}
/**
* __clear_bit - Clears a bit in memory
* @nr: the bit to clear
* @addr: the address to start counting from
*
* Unlike clear_bit(), this function is non-atomic. If it is called on the same
* region of memory concurrently, the effect may be that only one operation
* succeeds.
*/
static inline void __clear_bit(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
arch___clear_bit(nr, addr);
}
/**
* __change_bit - Toggle a bit in memory
* @nr: the bit to change
* @addr: the address to start counting from
*
* Unlike change_bit(), this function is non-atomic. If it is called on the same
* region of memory concurrently, the effect may be that only one operation
* succeeds.
*/
static inline void __change_bit(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
arch___change_bit(nr, addr);
}
/**
* __test_and_set_bit - Set a bit and return its old value
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is non-atomic. If two instances of this operation race, one
* can appear to succeed but actually fail.
*/
static inline bool __test_and_set_bit(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
return arch___test_and_set_bit(nr, addr);
}
/**
* __test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
* This operation is non-atomic. If two instances of this operation race, one
* can appear to succeed but actually fail.
*/
static inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
return arch___test_and_clear_bit(nr, addr);
}
/**
* __test_and_change_bit - Change a bit and return its old value
* @nr: Bit to change
* @addr: Address to count from
*
* This operation is non-atomic. If two instances of this operation race, one
* can appear to succeed but actually fail.
*/
static inline bool __test_and_change_bit(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
return arch___test_and_change_bit(nr, addr);
}
/**
* test_bit - Determine whether a bit is set
* @nr: bit number to test
* @addr: Address to start counting from
*/
static inline bool test_bit(long nr, const volatile unsigned long *addr)
{
kasan_check_read(addr + BIT_WORD(nr), sizeof(long));
return arch_test_bit(nr, addr);
}
#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */