From: Peter Zijlstra <peterz@infradead.org>
To: Marco Elver <elver@google.com>
Cc: linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com,
Will Deacon <will@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
"Paul E . McKenney" <paulmck@kernel.org>,
Ingo Molnar <mingo@kernel.org>
Subject: Re: [PATCH] READ_ONCE, WRITE_ONCE, kcsan: Perform checks in __*_ONCE variants
Date: Tue, 12 May 2020 21:09:10 +0200 [thread overview]
Message-ID: <20200512190910.GM2957@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <20200512183839.2373-1-elver@google.com>
On Tue, May 12, 2020 at 08:38:39PM +0200, Marco Elver wrote:
> diff --git a/include/linux/compiler.h b/include/linux/compiler.h
> index 741c93c62ecf..e902ca5de811 100644
> --- a/include/linux/compiler.h
> +++ b/include/linux/compiler.h
> @@ -224,13 +224,16 @@ void ftrace_likely_update(struct ftrace_likely_data *f, int val,
> * atomicity or dependency ordering guarantees. Note that this may result
> * in tears!
> */
> -#define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x))
> +#define __READ_ONCE(x) \
> +({ \
> + kcsan_check_atomic_read(&(x), sizeof(x)); \
> + data_race((*(const volatile __unqual_scalar_typeof(x) *)&(x))); \
> +})
NAK
This will actively insert instrumentation into __READ_ONCE() and I need
it to not have any.
next prev parent reply other threads:[~2020-05-12 19:09 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-05-12 18:38 Marco Elver
2020-05-12 19:09 ` Peter Zijlstra [this message]
2020-05-19 21:10 ` Qian Cai
2020-05-19 21:25 ` Marco Elver
2020-05-19 21:45 ` Qian Cai
2020-05-19 22:05 ` Thomas Gleixner
2020-05-20 2:28 ` Qian Cai
2020-05-20 2:47 ` Nathan Chancellor
2020-05-20 3:16 ` Qian Cai
2020-05-20 3:44 ` Nathan Chancellor
2020-05-20 7:28 ` Marco Elver
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