From: Arnd Bergmann <arnd@arndb.de>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>,
Arjan van de Ven <arjan@infradead.org>,
Roland McGrath <roland@redhat.com>,
Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>,
Containers <containers@lists.linux-foundation.org>,
Nathan Lynch <nathanl@austin.ibm.com>,
linux-kernel@vger.kernel.org,
"Eric W. Biederman" <ebiederm@xmission.com>,
mingo@elte.hu, Alexey Dobriyan <adobriyan@gmail.com>,
Pavel Emelyanov <xemul@openvz.org>,
linux-api@vger.kernel.org, kosaki.motohiro@jp.fujitsu.com
Subject: Re: [RFC][v7][PATCH 8/9]: Define clone2() syscall
Date: Wed, 30 Sep 2009 19:59:40 +0200 [thread overview]
Message-ID: <200909301959.41706.arnd@arndb.de> (raw)
In-Reply-To: <alpine.LFD.2.01.0909300925170.6996@localhost.localdomain>
On Wednesday 30 September 2009, Linus Torvalds wrote:
> Umm. I don't think that is possible.
>
> You need architecture-specific code to even get access to all registers to
> copy and get a signal-handler-compatible stack frame. See for example
> arch/alpha/kernel/entry.S with the switch-stack thing etc. I don't think
> there is any way to make that even remotely architecture-neutral.
Right, you still need to save all the registers from the entry code.
I was under the wrong assumption that task_pt_regs(current)
would give the full register set on all architectures.
However, I'd still hope that a new system call can be defined in
a way that you only need to have an assembly wrapper to save
the full pt_regs, but no arch specific code to get the syscall arguments
out of that again. In do_clone(), you need a pointer to pt_regs and
the user stack pointer, but that can be generated from
user_stack_pointer(regs).
Does task_pt_regs(current) give the right pointer on all architectures
or do we also need to pass the regs into the syscall?
Arnd <><
next prev parent reply other threads:[~2009-09-30 18:02 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-09-24 16:55 [RFC][v7][PATCH 0/9] Implement clone2() system call Sukadev Bhattiprolu
2009-09-24 17:00 ` [RFC][v7][PATCH 1/9]: Factor out code to allocate pidmap page Sukadev Bhattiprolu
2009-09-24 17:00 ` [RFC][v7][PATCH 2/9]: Have alloc_pidmap() return actual error code Sukadev Bhattiprolu
2009-09-24 17:01 ` [RFC][v7][PATCH 3/9] Make pid_max a pid_ns property Sukadev Bhattiprolu
2009-09-24 17:45 ` Oren Laadan
2009-09-24 17:01 ` [RFC][v7][PATCH 4/9]: Add target_pid parameter to alloc_pidmap() Sukadev Bhattiprolu
2009-09-24 17:47 ` Oren Laadan
2009-09-24 17:01 ` [RFC][v7][PATCH 5/9]: Add target_pids parameter to alloc_pid() Sukadev Bhattiprolu
2009-09-24 17:02 ` [RFC][v7][PATCH 6/9]: Add target_pids parameter to copy_process() Sukadev Bhattiprolu
2009-09-24 17:02 ` [RFC][v7][PATCH 7/9]: Define do_fork_with_pids() Sukadev Bhattiprolu
2009-09-24 17:03 ` [RFC][v7][PATCH 8/9]: Define clone2() syscall Sukadev Bhattiprolu
2009-09-24 21:43 ` Arnd Bergmann
2009-09-25 8:23 ` Louis Rilling
2009-09-25 10:56 ` Louis Rilling
2009-09-29 18:05 ` Sukadev Bhattiprolu
2009-09-29 18:40 ` Roland McGrath
2009-09-29 18:44 ` H. Peter Anvin
2009-09-29 19:02 ` Arjan van de Ven
2009-09-29 19:10 ` Linus Torvalds
2009-09-29 20:02 ` H. Peter Anvin
2009-09-29 22:11 ` Linus Torvalds
2009-09-29 22:19 ` H. Peter Anvin
2009-09-30 16:15 ` Arnd Bergmann
2009-09-30 16:27 ` Linus Torvalds
2009-09-30 17:59 ` Arnd Bergmann [this message]
2009-09-30 19:14 ` Linus Torvalds
2009-09-30 6:48 ` Roland McGrath
2009-09-29 20:00 ` H. Peter Anvin
2009-09-29 21:58 ` Oren Laadan
2009-09-24 17:03 ` [RFC][v7][PATCH 9/9]: Document " Sukadev Bhattiprolu
2009-09-24 18:05 ` Randy Dunlap
2009-09-25 2:31 ` KOSAKI Motohiro
2009-09-24 17:44 ` [RFC][v7][PATCH 0/9] Implement clone2() system call Oren Laadan
2009-09-24 20:15 ` Sukadev Bhattiprolu
2009-09-24 22:06 ` Oren Laadan
2009-09-24 22:21 ` Arnd Bergmann
2009-09-24 23:19 ` Oren Laadan
2009-10-01 2:36 ` Sukadev Bhattiprolu
2009-10-01 15:19 ` Oren Laadan
2009-09-24 17:57 ` Alexey Dobriyan
2009-09-24 18:35 ` Serge E. Hallyn
2009-09-30 5:34 ` Alexey Dobriyan
2009-09-30 17:41 ` Oren Laadan
2009-10-02 20:27 ` Alexey Dobriyan
2009-10-02 21:06 ` Oren Laadan
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