Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 1 Nov 2000 07:22:37 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 1 Nov 2000 07:22:17 -0500 Received: from ns.dce.bg ([212.50.14.242]:57360 "HELO home.dce.bg") by vger.kernel.org with SMTP id ; Wed, 1 Nov 2000 07:22:13 -0500 Message-ID: <3A000ADC.43DEB50C@dce.bg> Date: Wed, 01 Nov 2000 14:21:48 +0200 From: Petko Manolov Organization: Deltacom Electronics X-Mailer: Mozilla 4.75 [en] (X11; U; Linux 2.4.0-test10 i686) X-Accept-Language: en, bg MIME-Version: 1.0 To: mdaljeet@in.ibm.com CC: linux-kernel@vger.kernel.org Subject: Re: system call handling In-Reply-To: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org mdaljeet@in.ibm.com wrote: > > Hi, > > By looking into the structure of GDT as used by linux kernel(file > include/asm/desc.c, kernel ver 2.4), it appears as if linux kernel does not > use the "call gate descriptors" for system call handling. Is this correct? You're looking at wrong place. Look at linux/arch/i386/kernel/traps.c > If it is correct then how does the system calls are handled by the kernel > (basically how does the control gets transferred to kernel)? Does the CS of > linux kernel handles the system calls? what are the advantages of using > this scheme? System calls in Linux are performed as an interrupt gate (0x80). It is not necessary to use call gate. On i386 arch both are almost identical. Petkan - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/