linux-kernel - Re: [RFC][v6][PATCH 8/9]: Define clone_with

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: <200909111231.30495.arnd@arndb.de>
Date:	Fri, 11 Sep 2009 12:31:29 +0200
From:	Arnd Bergmann <arnd@...db.de>
To:	Sukadev Bhattiprolu <sukadev@...ux.vnet.ibm.com>
Cc:	linux-kernel@...r.kernel.org, Oren Laadan <orenl@...columbia.edu>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Alexey Dobriyan <adobriyan@...il.com>,
	Pavel Emelyanov <xemul@...nvz.org>,
	Andrew Morton <akpm@...l.org>, torvalds@...ux-foundation.org,
	mikew@...gle.com, mingo@...e.hu, hpa@...or.com,
	Nathan Lynch <nathanl@...tin.ibm.com>,
	Containers <containers@...ts.linux-foundation.org>,
	sukadev@...ibm.com
Subject: Re: [RFC][v6][PATCH 8/9]: Define clone_with_pids() syscall

On Thursday 10 September 2009, Sukadev Bhattiprolu wrote:
> Since this is a variant of clone() and clone is listed as a PTREGSCALL(),
> I pass in the pt_regs.
> 
> arch/x86/kernel/entry_32.S lists clone() under this comment:
> 
> /*
>  * System calls that need a pt_regs pointer.
>  */
> 
> Is there a guideline on what system calls use/need pt_regs ?

You need pt_regs if you access any registers from the user task
other than the argument registers. In case of clone(), this is
the user stack pointer.

The user_stack_pointer() function is relatively new, before this
you couldn't get the stack pointer out of pt_regs in a generic
way.

	Arnd <><
--
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/