linux-kernel - Re: Why set ORIG_EAX(%esp) to -1 in arch/i386/kernel/entry.S:error

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 for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <Pine.LNX.4.64.0608291455120.27779@g5.osdl.org>
Date:	Tue, 29 Aug 2006 14:55:53 -0700 (PDT)
From:	Linus Torvalds <torvalds@...l.org>
To:	Jeremy Fitzhardinge <jeremy@...p.org>
cc:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Andi Kleen <ak@...e.de>, Zachary Amsden <zach@...are.com>,
	Chuck Ebbert <76306.1226@...puserve.com>
Subject: Re: Why set ORIG_EAX(%esp) to -1 in arch/i386/kernel/entry.S:error_code?



On Tue, 29 Aug 2006, Jeremy Fitzhardinge wrote:
>
> There doesn't seem much point; nothing seems to use it on the trap-handling
> paths.  Is it a historical left-over?

No. It's important that ORIG_EAX be set to some value that is _not_ a 
valid system call number, so that the system call restart logic (see the 
signal handling code) doesn't trigger.

		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/