From: Constantine Gavrilov <constg@qlusters.com>
To: Brian Gerst <bgerst@didntduck.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: Calling syscalls from x86-64 kernel results in a crash on Opteron machines
Date: Mon, 13 Sep 2004 18:26:37 +0300 [thread overview]
Message-ID: <4145BC2D.7020209@qlusters.com> (raw)
In-Reply-To: <4145B606.5080505@didntduck.org>
Brian Gerst wrote:
>
> You should never use the unistd.h macros from kernel space. Call
> sys_foo() directly. This may mean you have to export it. The reason
> it crashes is that the "syscall" opcode used by the x86-64 macros
> (unlike the "int $0x80" for i386) causes a fault when already running
> in kernel space.
>
> --
> Brian Gerst
I can see from the crash report that the fault happens. I want to
understand why.
I can use workarounds. (Calling sys_foo() directly from module can be a
problem -- I would have to know the "versioned" function name or the
address of the function within the kernel space. Calling an entry from
the syscall table is much easier.)
--
----------------------------------------
Constantine Gavrilov
Kernel Developer
Qlusters Software Ltd
1 Azrieli Center, Tel-Aviv
Phone: +972-3-6081977
Fax: +972-3-6081841
----------------------------------------
next prev parent reply other threads:[~2004-09-13 15:53 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-13 14:04 Calling syscalls from x86-64 kernel results in a crash on Opteron machines Constantine Gavrilov
2004-09-13 14:38 ` Christoph Hellwig
2004-09-13 15:05 ` Constantine Gavrilov
2004-09-13 16:17 ` Andrea Arcangeli
2004-09-13 16:41 ` Stephen Hemminger
2004-09-13 20:08 ` Andrea Arcangeli
2004-09-13 16:42 ` Greg KH
2004-09-13 17:21 ` Brian Gerst
2004-09-14 2:04 ` William Lee Irwin III
2004-09-13 14:44 ` Arnd Bergmann
2004-09-13 15:18 ` Constantine Gavrilov
2004-09-13 19:39 ` H. Peter Anvin
2004-09-13 15:00 ` Brian Gerst
2004-09-13 15:26 ` Constantine Gavrilov [this message]
[not found] <2DZQy-7TB-7@gated-at.bofh.it>
2004-09-13 14:31 ` Andi Kleen
2004-09-13 15:28 ` Constantine Gavrilov
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