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
This commit is contained in:
Daniel Axtens 2019-08-20 12:49:40 +10:00 committed by Michael Ellerman
parent da0c9ea146
commit 81d2c6f819
7 changed files with 317 additions and 266 deletions

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@ -57,7 +57,22 @@ The Linux kernel provides more basic utility functions.
Bit Operations
--------------
.. kernel-doc:: include/asm-generic/bitops-instrumented.h
Atomic Operations
~~~~~~~~~~~~~~~~~
.. kernel-doc:: include/asm-generic/bitops/instrumented-atomic.h
:internal:
Non-atomic Operations
~~~~~~~~~~~~~~~~~~~~~
.. kernel-doc:: include/asm-generic/bitops/instrumented-non-atomic.h
:internal:
Locking Operations
~~~~~~~~~~~~~~~~~~
.. kernel-doc:: include/asm-generic/bitops/instrumented-lock.h
:internal:
Bitmap Operations

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@ -241,7 +241,9 @@ static inline void arch___clear_bit_unlock(unsigned long nr,
arch___clear_bit(nr, ptr);
}
#include <asm-generic/bitops-instrumented.h>
#include <asm-generic/bitops/instrumented-atomic.h>
#include <asm-generic/bitops/instrumented-non-atomic.h>
#include <asm-generic/bitops/instrumented-lock.h>
/*
* Functions which use MSB0 bit numbering.

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@ -388,7 +388,9 @@ static __always_inline int fls64(__u64 x)
#include <asm-generic/bitops/const_hweight.h>
#include <asm-generic/bitops-instrumented.h>
#include <asm-generic/bitops/instrumented-atomic.h>
#include <asm-generic/bitops/instrumented-non-atomic.h>
#include <asm-generic/bitops/instrumented-lock.h>
#include <asm-generic/bitops/le.h>

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@ -1,263 +0,0 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* This file provides wrappers with sanitizer instrumentation for 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_H
#define _ASM_GENERIC_BITOPS_INSTRUMENTED_H
#include <linux/kasan-checks.h>
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* This is a relaxed atomic operation (no implied memory barriers).
*
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
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);
}
/**
* __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: Bit to clear
* @addr: Address to start counting from
*
* This is a relaxed atomic operation (no implied memory barriers).
*/
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);
}
/**
* __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);
}
/**
* clear_bit_unlock - Clear a bit in memory, for unlock
* @nr: the bit to set
* @addr: the address to start counting from
*
* This operation is atomic and provides release barrier semantics.
*/
static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
arch_clear_bit_unlock(nr, addr);
}
/**
* __clear_bit_unlock - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* This is a non-atomic operation but implies a release barrier before the
* memory operation. It can be used for an unlock if no other CPUs can
* concurrently modify other bits in the word.
*/
static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
arch___clear_bit_unlock(nr, addr);
}
/**
* change_bit - Toggle a bit in memory
* @nr: Bit to change
* @addr: Address to start counting from
*
* This is a relaxed atomic operation (no implied memory barriers).
*
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
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);
}
/**
* __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 is an atomic fully-ordered operation (implied full memory barrier).
*/
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_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_set_bit_lock - Set a bit and return its old value, for lock
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and provides acquire barrier semantics if
* the returned value is 0.
* It can be used to implement bit locks.
*/
static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
return arch_test_and_set_bit_lock(nr, addr);
}
/**
* test_and_clear_bit - Clear a bit and return its old value
* @nr: Bit to clear
* @addr: Address to count from
*
* This is an atomic fully-ordered operation (implied full memory barrier).
*/
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_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 is an atomic fully-ordered operation (implied full memory barrier).
*/
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_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);
}
#if defined(arch_clear_bit_unlock_is_negative_byte)
/**
* clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom
* byte is negative, for unlock.
* @nr: the bit to clear
* @addr: the address to start counting from
*
* This operation is atomic and provides release barrier semantics.
*
* This is a bit of a one-trick-pony for the filemap code, which clears
* PG_locked and tests PG_waiters,
*/
static inline bool
clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
return arch_clear_bit_unlock_is_negative_byte(nr, addr);
}
/* Let everybody know we have it. */
#define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte
#endif
#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_H */

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@ -0,0 +1,100 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* This file provides wrappers with sanitizer instrumentation for 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_ATOMIC_H
#define _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H
#include <linux/kasan-checks.h>
/**
* set_bit - Atomically set a bit in memory
* @nr: the bit to set
* @addr: the address to start counting from
*
* This is a relaxed atomic operation (no implied memory barriers).
*
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
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: Bit to clear
* @addr: Address to start counting from
*
* This is a relaxed atomic operation (no implied memory barriers).
*/
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: Bit to change
* @addr: Address to start counting from
*
* This is a relaxed atomic operation (no implied memory barriers).
*
* Note that @nr may be almost arbitrarily large; this function is not
* restricted to acting on a single-word quantity.
*/
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 is an atomic fully-ordered operation (implied full memory barrier).
*/
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 is an atomic fully-ordered operation (implied full memory barrier).
*/
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 is an atomic fully-ordered operation (implied full memory barrier).
*/
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);
}
#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */

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@ -0,0 +1,81 @@
/* SPDX-License-Identifier: GPL-2.0 */
/*
* This file provides wrappers with sanitizer instrumentation for bit
* locking 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_LOCK_H
#define _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H
#include <linux/kasan-checks.h>
/**
* clear_bit_unlock - Clear a bit in memory, for unlock
* @nr: the bit to set
* @addr: the address to start counting from
*
* This operation is atomic and provides release barrier semantics.
*/
static inline void clear_bit_unlock(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
arch_clear_bit_unlock(nr, addr);
}
/**
* __clear_bit_unlock - Clears a bit in memory
* @nr: Bit to clear
* @addr: Address to start counting from
*
* This is a non-atomic operation but implies a release barrier before the
* memory operation. It can be used for an unlock if no other CPUs can
* concurrently modify other bits in the word.
*/
static inline void __clear_bit_unlock(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
arch___clear_bit_unlock(nr, addr);
}
/**
* test_and_set_bit_lock - Set a bit and return its old value, for lock
* @nr: Bit to set
* @addr: Address to count from
*
* This operation is atomic and provides acquire barrier semantics if
* the returned value is 0.
* It can be used to implement bit locks.
*/
static inline bool test_and_set_bit_lock(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
return arch_test_and_set_bit_lock(nr, addr);
}
#if defined(arch_clear_bit_unlock_is_negative_byte)
/**
* clear_bit_unlock_is_negative_byte - Clear a bit in memory and test if bottom
* byte is negative, for unlock.
* @nr: the bit to clear
* @addr: the address to start counting from
*
* This operation is atomic and provides release barrier semantics.
*
* This is a bit of a one-trick-pony for the filemap code, which clears
* PG_locked and tests PG_waiters,
*/
static inline bool
clear_bit_unlock_is_negative_byte(long nr, volatile unsigned long *addr)
{
kasan_check_write(addr + BIT_WORD(nr), sizeof(long));
return arch_clear_bit_unlock_is_negative_byte(nr, addr);
}
/* Let everybody know we have it. */
#define clear_bit_unlock_is_negative_byte clear_bit_unlock_is_negative_byte
#endif
#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_LOCK_H */

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@ -0,0 +1,114 @@
/* 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 */