lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Message-ID: <CA+55aFyd5C_G=LDs-EbWaDjGXkOZ2AvZtZSr+Jp0fWo5=FgsQQ@mail.gmail.com>
Date:	Wed, 20 Nov 2013 13:44:16 -0800
From:	Linus Torvalds <torvalds@...ux-foundation.org>
To:	"H. Peter Anvin" <hpa@...or.com>
Cc:	"H. Peter Anvin" <hpa@...ux.intel.com>,
	Ingo Molnar <mingo@...nel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-tip-commits@...r.kernel.org,
	Fenghua Yu <fenghua.yu@...el.com>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [tip:x86/asm] x86-64, copy_user: Remove zero byte check before
 copy user buffer.

On Wed, Nov 20, 2013 at 12:36 PM, H. Peter Anvin <hpa@...or.com> wrote:
>
> That being said, "lea (%rdx,%rcx,8),%ecx" (leal, as opposed to leaq) is
> a perfectly legitimate instruction and actually one byte shorter.  The
> big question is if some broken version of gas will choke on it.

At least gcc-4.8.2 generates that instruction (try multiplying an
integer value by 9), so I guess gas will be happy. Except gcc uses
"leal", so to be safe..

              Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ