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From: David Laight <David.Laight@ACULAB.COM>
To: 'Nick Desaulniers' <ndesaulniers@google.com>,
	Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>
Cc: "linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>,
	"Alexander Viro" <viro@zeniv.linux.org.uk>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andi Kleen <ak@linux.intel.com>, Christoph Hellwig <hch@lst.de>,
	Eric Dumazet <edumazet@google.com>,
	"Darrick J. Wong" <darrick.wong@oracle.com>,
	"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"llvm@lists.linux.dev" <llvm@lists.linux.dev>,
	Paul Kirth <paulkirth@google.com>
Subject: RE: [PATCH] fs/select: avoid clang stack usage warning
Date: Sun, 9 Oct 2022 10:49:52 +0000	[thread overview]
Message-ID: <b211e3a2549844fa957ca84b9257872d@AcuMS.aculab.com> (raw)
In-Reply-To: <CAKwvOdkEied8hf6Oid0sGf0ybF2WqrzOvtRiXa=j7Ms-Rc6uBA@mail.gmail.com>

From: Nick Desaulniers
> Sent: 07 October 2022 20:04
...
> It looks like for arrays INIT_STACK_ALL_PATTERN uses memset to fill
> the array with 0xFF rather than 0x00 used by INIT_STACK_ALL_ZERO. Not
> sure why that would make a difference, but curious that it does.

How much performance does filling the array cost?
I'd suspect it is enough to be measurable.

	David

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Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

  parent reply	other threads:[~2022-10-09 10:49 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-03-07  9:01 [PATCH] fs/select: avoid clang stack usage warning Arnd Bergmann
2019-03-07 16:19 ` Andi Kleen
2022-10-06 22:21 ` Nick Desaulniers
2022-10-07  8:28   ` Arnd Bergmann
2022-10-07 19:04     ` Nick Desaulniers
2022-10-07 20:11       ` [PATCH] fs/select: mark do_select noinline_for_stack for 32b Nick Desaulniers
2022-10-10  7:44         ` Christoph Hellwig
2022-10-10 16:42           ` Nick Desaulniers
2022-10-10 19:55         ` Arnd Bergmann
2022-10-13 18:52         ` kernel test robot
2022-10-07 21:42       ` [PATCH] fs/select: avoid clang stack usage warning Arnd Bergmann
2022-10-07 22:54         ` Nick Desaulniers
2022-10-10 18:40           ` Nick Desaulniers
2022-10-11 12:46             ` Arnd Bergmann
2022-10-11 20:55               ` [PATCH v2] fs/select: mark do_select noinline_for_stack Nick Desaulniers
2022-10-14 22:39                 ` Nathan Chancellor
2022-10-07 23:17         ` [PATCH] fs/select: avoid clang stack usage warning Kees Cook
2022-10-09 10:49       ` David Laight [this message]
2022-10-08  1:46   ` Andi Kleen
2022-10-11 20:50     ` Nick Desaulniers
2022-10-13 20:52       ` Andi Kleen

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