From: Kees Cook <kees@kernel.org>
To: Alexander Lobakin <aleksander.lobakin@intel.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>,
linux-hardening@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3][next] overflow: Fix direct struct member initialization in _DEFINE_FLEX()
Date: Fri, 30 May 2025 11:52:45 -0700 [thread overview]
Message-ID: <202505301151.6CEDBBF8@keescook> (raw)
In-Reply-To: <202505301054.A786A183@keescook>
On Fri, May 30, 2025 at 11:06:01AM -0700, Kees Cook wrote:
> #define __DEFINE_FLEX(type, name, member, count, trailer...) \
> _Static_assert(__builtin_constant_p(count), \
> "onstack flex array members require compile-time const count"); \
> union { \
> u8 bytes[struct_size_t(type, member, count)]; \
> type obj; \
> } name##_u trailer; \
> type *name = (type *)&name##_u
>
> #define _DEFINE_FLEX(type, name, member, count, initializer...) \
> __DEFINE_FLEX(type, name, member, count, = { .obj = initializer })
> [...]
> Does that look like what you'd want? (Note I didn't actually build this;
> I want to make sure the concept is workable...)
FWIW, this is working as expected: https://godbolt.org/z/P7Go8Tr33
I'll send a proper patch...
--
Kees Cook
prev parent reply other threads:[~2025-05-30 18:52 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-05-02 0:44 [PATCH v3][next] overflow: Fix direct struct member initialization in _DEFINE_FLEX() Gustavo A. R. Silva
2025-05-02 2:26 ` Kees Cook
2025-05-30 14:59 ` Alexander Lobakin
2025-05-30 18:06 ` Kees Cook
2025-05-30 18:52 ` Kees Cook [this message]
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