From: David Laight <David.Laight@ACULAB.COM>
To: 'Przemek Kitszel' <przemyslaw.kitszel@intel.com>,
Kees Cook <keescook@chromium.org>,
"netdev@vger.kernel.org" <netdev@vger.kernel.org>
Cc: Jacob Keller <jacob.e.keller@intel.com>,
"intel-wired-lan@lists.osuosl.org"
<intel-wired-lan@lists.osuosl.org>,
Alexander Lobakin <aleksander.lobakin@intel.com>,
"linux-hardening@vger.kernel.org"
<linux-hardening@vger.kernel.org>,
"Steven Zou" <steven.zou@intel.com>
Subject: RE: [PATCH net-next v3 1/7] overflow: add DEFINE_FLEX() for on-stack allocs
Date: Thu, 17 Aug 2023 14:35:23 +0000 [thread overview]
Message-ID: <1f9cb37f21294c31a01af62fd920f070@AcuMS.aculab.com> (raw)
In-Reply-To: <20230816140623.452869-2-przemyslaw.kitszel@intel.com>
From: Przemek Kitszel
> Sent: Wednesday, August 16, 2023 3:06 PM
>
> Using underlying array for on-stack storage lets us to declare
> known-at-compile-time structures without kzalloc().
Isn't DEFINE_FLEX() a bit misleading?
One thing it isn't is 'flexible' since it has a fixed size.
> +#define DEFINE_FLEX(type, name, member, count) \
> + union { \
> + u8 bytes[struct_size_t(type, member, count)]; \
> + type obj; \
> + } name##_u __aligned(_Alignof(type)) = {}; \
You shouldn't need the _Alignof() it is the default.
I'm not sure you should be forcing the memset() either.
> + type *name = (type *)&name##_u
How about?
type *const name = &name_##_u.obj;
You might want to add:
Static_assert(is_constexpr(count), "DEFINE_FLEX: non-constant count " #count);
David
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Registration No: 1397386 (Wales)
next prev parent reply other threads:[~2023-08-17 14:35 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-16 14:06 [PATCH net-next v3 0/7] introduce DEFINE_FLEX() macro Przemek Kitszel
2023-08-16 14:06 ` [PATCH net-next v3 1/7] overflow: add DEFINE_FLEX() for on-stack allocs Przemek Kitszel
2023-08-16 16:35 ` kernel test robot
2023-08-18 10:37 ` Przemek Kitszel
2023-08-18 11:10 ` Miguel Ojeda
2023-08-18 12:07 ` Philip Li
2023-08-19 10:06 ` Greg KH
2023-08-16 20:38 ` Kees Cook
2023-08-17 14:35 ` David Laight [this message]
2023-08-17 17:00 ` Kees Cook
2023-08-18 7:14 ` David Laight
2023-08-18 10:28 ` Przemek Kitszel
2023-08-18 10:49 ` David Laight
2023-08-23 20:52 ` Przemek Kitszel
2023-08-28 14:41 ` Przemek Kitszel
2023-08-16 14:06 ` [PATCH net-next v3 2/7] ice: ice_sched_remove_elems: replace 1 elem array param by u32 Przemek Kitszel
2023-08-16 14:06 ` [PATCH net-next v3 3/7] ice: drop two params of ice_aq_move_sched_elems() Przemek Kitszel
2023-08-16 14:06 ` [PATCH net-next v3 4/7] ice: make use of DEFINE_FLEX() in ice_ddp.c Przemek Kitszel
2023-08-16 14:06 ` [PATCH net-next v3 5/7] ice: make use of DEFINE_FLEX() for struct ice_aqc_add_tx_qgrp Przemek Kitszel
2023-08-16 14:06 ` [PATCH net-next v3 6/7] ice: make use of DEFINE_FLEX() for struct ice_aqc_dis_txq_item Przemek Kitszel
2023-08-16 14:06 ` [PATCH net-next v3 7/7] ice: make use of DEFINE_FLEX() in ice_switch.c Przemek Kitszel
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