mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
synced 2025-08-28 00:19:36 +00:00
83dc0370f9
Port over the definition of data_race() so we can build tools/virtio.
cc -g -O2 -Werror -Wno-maybe-uninitialized -Wall -I.
-I../include/ -I ../../usr/include/ -Wno-pointer-sign
-fno-strict-overflow -fno-strict-aliasing -fno-common
-MMD -U_FORTIFY_SOURCE -include ../../include/linux/kconfig.h
-mfunction-return=thunk -fcf-protection=none
-mindirect-branch-register -pthread
-c -o virtio_ring.o ../../drivers/virtio/virtio_ring.c
../../drivers/virtio/virtio_ring.c: in function'vring_interrupt':
../../drivers/virtio/virtio_ring.c:2711:17: error：Implicit declaration function'data_race' [-Wimplicit-function-declaration]
2711 | data_race(vq->event_triggered = true);
| ^~~~~~~~~
Signed-off-by: Yufeng Wang <wangyufeng@kylinos.cn>
Message-Id: <20250114033635.20623-1-wangyufeng@kylinos.cn>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
39 lines
1.4 KiB
C
39 lines
1.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef LINUX_COMPILER_H
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#define LINUX_COMPILER_H
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#include "../../../include/linux/compiler_types.h"
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#define WRITE_ONCE(var, val) \
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(*((volatile typeof(val) *)(&(var))) = (val))
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#define READ_ONCE(var) (*((volatile typeof(var) *)(&(var))))
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#define __aligned(x) __attribute((__aligned__(x)))
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/**
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* data_race - mark an expression as containing intentional data races
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*
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* This data_race() macro is useful for situations in which data races
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* should be forgiven. One example is diagnostic code that accesses
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* shared variables but is not a part of the core synchronization design.
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* For example, if accesses to a given variable are protected by a lock,
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* except for diagnostic code, then the accesses under the lock should
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* be plain C-language accesses and those in the diagnostic code should
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* use data_race(). This way, KCSAN will complain if buggy lockless
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* accesses to that variable are introduced, even if the buggy accesses
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* are protected by READ_ONCE() or WRITE_ONCE().
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*
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* This macro *does not* affect normal code generation, but is a hint
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* to tooling that data races here are to be ignored. If the access must
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* be atomic *and* KCSAN should ignore the access, use both data_race()
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* and READ_ONCE(), for example, data_race(READ_ONCE(x)).
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*/
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#define data_race(expr) \
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({ \
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__auto_type __v = (expr); \
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__v; \
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})
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#endif
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