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From: Justin Stitt <justinstitt@google.com>
Date: Mon, 8 Apr 2024 14:43:08 -0700
Message-ID: <CAFhGd8pFy5=BYcYr_fa4fkLB54ktXRwS=QVJunzMd5z15RYDaA@mail.gmail.com>
Subject: Re: [PATCH v3 1/3] net: mana: Add flex array to struct mana_cfg_rx_steer_req_v2
To: Erick Archer <erick.archer@outlook.com>
Cc: Long Li <longli@microsoft.com>, Ajay Sharma <sharmaajay@microsoft.com>, 
	"K. Y. Srinivasan" <kys@microsoft.com>, Haiyang Zhang <haiyangz@microsoft.com>, Wei Liu <wei.liu@kernel.org>, 
	Dexuan Cui <decui@microsoft.com>, "David S. Miller" <davem@davemloft.net>, 
	Eric Dumazet <edumazet@google.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, 
	Kees Cook <keescook@chromium.org>, "Gustavo A. R. Silva" <gustavoars@kernel.org>, 
	Nathan Chancellor <nathan@kernel.org>, Nick Desaulniers <ndesaulniers@google.com>, 
	Bill Wendling <morbo@google.com>, Jason Gunthorpe <jgg@ziepe.ca>, Leon Romanovsky <leon@kernel.org>, 
	Shradha Gupta <shradhagupta@linux.microsoft.com>, 
	Konstantin Taranov <kotaranov@microsoft.com>, linux-rdma@vger.kernel.org, 
	linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, 
	linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org, 
	llvm@lists.linux.dev
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On Mon, Apr 8, 2024 at 2:35=E2=80=AFPM Justin Stitt <justinstitt@google.com=
> wrote:
>
> Hi,
>
> On Sat, Apr 06, 2024 at 04:23:35PM +0200, Erick Archer wrote:
> > The "struct mana_cfg_rx_steer_req_v2" uses a dynamically sized set of
> > trailing elements. Specifically, it uses a "mana_handle_t" array. So,
> > use the preferred way in the kernel declaring a flexible array [1].
> >
> > At the same time, prepare for the coming implementation by GCC and Clan=
g
> > of the __counted_by attribute. Flexible array members annotated with
> > __counted_by can have their accesses bounds-checked at run-time via
> > CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for
> > strcpy/memcpy-family functions).
> >
> > This is a previous step to refactor the two consumers of this structure=
.
> >
> >  drivers/infiniband/hw/mana/qp.c
> >  drivers/net/ethernet/microsoft/mana/mana_en.c
> >
> > The ultimate goal is to avoid the open-coded arithmetic in the memory
> > allocator functions [2] using the "struct_size" macro.
> >
> > Link: https://www.kernel.org/doc/html/next/process/deprecated.html#zero=
-length-and-one-element-arrays [1]
> > Link: https://www.kernel.org/doc/html/next/process/deprecated.html#open=
-coded-arithmetic-in-allocator-arguments [2]
> > Signed-off-by: Erick Archer <erick.archer@outlook.com>
>
> I think this could have all been one patch, I found myself jumping
> around the three patches here piecing together context.

I now see Leon said to combine them in v2. Whoops, sorry to give
conflicting feedback.

>
> Reviewed-by: Justin Stitt <justinstitt@google.com>
>
> > ---
> >  include/net/mana/mana.h | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/include/net/mana/mana.h b/include/net/mana/mana.h
> > index 4eeedf14711b..561f6719fb4e 100644
> > --- a/include/net/mana/mana.h
> > +++ b/include/net/mana/mana.h
> > @@ -670,6 +670,7 @@ struct mana_cfg_rx_steer_req_v2 {
> >       u8 hashkey[MANA_HASH_KEY_SIZE];
> >       u8 cqe_coalescing_enable;
> >       u8 reserved2[7];
> > +     mana_handle_t indir_tab[] __counted_by(num_indir_entries);
> >  }; /* HW DATA */
> >
> >  struct mana_cfg_rx_steer_resp {
> > --
> > 2.25.1
> >
>
> Thanks
> Justin