mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-10-12 03:26:26 +00:00
acb13ea0ba
Make it consistent with the atomic/atomic-instrumented.h helpers.
And defconfig size is actually going down!
text data bss dec hex filename
22352096 8213152 1917164 32482412 1efa46c vmlinux.x86-64.defconfig.before
22350551 8213184 1917164 32480899 1ef9e83 vmlinux.x86-64.defconfig.after
Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Marco Elver <elver@google.com>
Link: https://lore.kernel.org/r/20220113155357.4706-2-bp@alien8.de
138 lines
4.3 KiB
C
138 lines
4.3 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/instrumented.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 __always_inline void __set_bit(long nr, volatile unsigned long *addr)
|
|
{
|
|
instrument_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 __always_inline void __clear_bit(long nr, volatile unsigned long *addr)
|
|
{
|
|
instrument_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 __always_inline void __change_bit(long nr, volatile unsigned long *addr)
|
|
{
|
|
instrument_write(addr + BIT_WORD(nr), sizeof(long));
|
|
arch___change_bit(nr, addr);
|
|
}
|
|
|
|
static __always_inline void __instrument_read_write_bitop(long nr, volatile unsigned long *addr)
|
|
{
|
|
if (IS_ENABLED(CONFIG_KCSAN_ASSUME_PLAIN_WRITES_ATOMIC)) {
|
|
/*
|
|
* We treat non-atomic read-write bitops a little more special.
|
|
* Given the operations here only modify a single bit, assuming
|
|
* non-atomicity of the writer is sufficient may be reasonable
|
|
* for certain usage (and follows the permissible nature of the
|
|
* assume-plain-writes-atomic rule):
|
|
* 1. report read-modify-write races -> check read;
|
|
* 2. do not report races with marked readers, but do report
|
|
* races with unmarked readers -> check "atomic" write.
|
|
*/
|
|
kcsan_check_read(addr + BIT_WORD(nr), sizeof(long));
|
|
/*
|
|
* Use generic write instrumentation, in case other sanitizers
|
|
* or tools are enabled alongside KCSAN.
|
|
*/
|
|
instrument_write(addr + BIT_WORD(nr), sizeof(long));
|
|
} else {
|
|
instrument_read_write(addr + BIT_WORD(nr), sizeof(long));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* __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 __always_inline bool __test_and_set_bit(long nr, volatile unsigned long *addr)
|
|
{
|
|
__instrument_read_write_bitop(nr, addr);
|
|
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 __always_inline bool __test_and_clear_bit(long nr, volatile unsigned long *addr)
|
|
{
|
|
__instrument_read_write_bitop(nr, addr);
|
|
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 __always_inline bool __test_and_change_bit(long nr, volatile unsigned long *addr)
|
|
{
|
|
__instrument_read_write_bitop(nr, addr);
|
|
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 __always_inline bool test_bit(long nr, const volatile unsigned long *addr)
|
|
{
|
|
instrument_atomic_read(addr + BIT_WORD(nr), sizeof(long));
|
|
return arch_test_bit(nr, addr);
|
|
}
|
|
|
|
#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */
|