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Date:   Tue, 6 Jun 2023 08:31:51 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Linus Torvalds <torvalds@linux-foundation.org>,
        gregkh@linuxfoundation.org, pbonzini@redhat.com,
        linux-kernel@vger.kernel.org, ojeda@kernel.org,
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        mathieu.desnoyers@efficios.com, jiangshanlai@gmail.com,
        rcu@vger.kernel.org, tj@kernel.org, tglx@linutronix.de,
        linux-toolchains@vger.kernel.org
Subject: Re: [PATCH v2 0/2] Lock and Pointer guards
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On Tue, Jun 06, 2023 at 11:42:51AM +0200, Peter Zijlstra wrote:
> [...]
> #define scoped_guard(_guard, _var...)                                  \
>        for (__ptr_guard(_guard, scope) = guard_init(_guard, _var),     \
>             *done = NULL; !done; done = (void *)1)

nit: Linus's example was "(void *)8" (instead of 1) because we've had
issues in the past with alignment warnings on archs that are sensitive
to it. (e.g. see the __is_constexpr() macro which is doing NULL/!NULL
comparisons.)

-- 
Kees Cook