Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266183AbUI0Hk3 (ORCPT ); Mon, 27 Sep 2004 03:40:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266200AbUI0Hk3 (ORCPT ); Mon, 27 Sep 2004 03:40:29 -0400 Received: from public.id2-vpn.continvity.gns.novell.com ([195.33.99.129]:7962 "EHLO emea1-mh.id2.novell.com") by vger.kernel.org with ESMTP id S266183AbUI0HkS (ORCPT ); Mon, 27 Sep 2004 03:40:18 -0400 Message-Id: X-Mailer: Novell GroupWise Internet Agent 6.5.2 Beta Date: Mon, 27 Sep 2004 09:40:57 +0200 From: "Jan Beulich" To: , Cc: , Subject: Re: i386 entry.S problems Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3321 Lines: 120 In addition to Andi Kleen's statement: Along with removing the remaining default LDT handling, wouldn't it be reasonable to then also remove the ill i386-specific code in kernel/exec_domain.c? Jan >>> Ingo Molnar 26.09.04 13:13:34 >>> * Arjan van de Ven wrote: > On Fri, 2004-09-24 at 16:12, Jan Beulich wrote: > > There appear to be two problems in i386's entry.S: > > > > (1) With CONFIG_REGPARM, lcall7 and lcall27 did not work (they pass the > > parameters to the actual handler procedure on the stack). > > I wonder why we still have the lcall7/lcall27 entry points in the > kernel; nothing can legitemately use them and in the last few years > they have only caused a few security issues. Can I ask why you didn't > just remove this code from the kernel ? patch below (against BK-curr) zaps the orphaned lcall7/lcall27 code. Ingo Signed-off-by: Ingo Molnar --- linux/arch/i386/kernel/entry.S.orig +++ linux/arch/i386/kernel/entry.S @@ -140,40 +140,6 @@ VM_MASK = 0x00020000 .previous - -ENTRY(lcall7) - pushfl # We get a different stack layout with call - # gates, which has to be cleaned up later.. - pushl %eax - SAVE_ALL - movl %esp, %ebp - pushl %ebp - pushl $0x7 -do_lcall: - movl EIP(%ebp), %eax # due to call gates, this is eflags, not eip.. - movl CS(%ebp), %edx # this is eip.. - movl EFLAGS(%ebp), %ecx # and this is cs.. - movl %eax,EFLAGS(%ebp) # - movl %edx,EIP(%ebp) # Now we move them to their "normal" places - movl %ecx,CS(%ebp) # - GET_THREAD_INFO_WITH_ESP(%ebp) # GET_THREAD_INFO - movl TI_exec_domain(%ebp), %edx # Get the execution domain - call *EXEC_DOMAIN_handler(%edx) # Call the handler for the domain - addl $4, %esp - popl %eax - jmp resume_userspace - -ENTRY(lcall27) - pushfl # We get a different stack layout with call - # gates, which has to be cleaned up later.. - pushl %eax - SAVE_ALL - movl %esp, %ebp - pushl %ebp - pushl $0x27 - jmp do_lcall - - ENTRY(ret_from_fork) pushl %eax call schedule_tail --- linux/arch/i386/kernel/traps.c.orig +++ linux/arch/i386/kernel/traps.c @@ -57,8 +57,6 @@ #include "mach_traps.h" asmlinkage int system_call(void); -asmlinkage void lcall7(void); -asmlinkage void lcall27(void); struct desc_struct default_ldt[] = { { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 }, { 0, 0 } }; @@ -1015,11 +1013,6 @@ static void __init set_system_gate(unsig _set_gate(idt_table+n,15,3,addr,__KERNEL_CS); } -static void __init set_call_gate(void *a, void *addr) -{ - _set_gate(a,12,3,addr,__KERNEL_CS); -} - static void __init set_task_gate(unsigned int n, unsigned int gdt_entry) { _set_gate(idt_table+n,5,0,0,(gdt_entry<<3)); @@ -1064,13 +1057,6 @@ void __init trap_init(void) set_system_gate(SYSCALL_VECTOR,&system_call); /* - * default LDT is a single-entry callgate to lcall7 for iBCS - * and a callgate to lcall27 for Solaris/x86 binaries - */ - set_call_gate(&default_ldt[0],lcall7); - set_call_gate(&default_ldt[4],lcall27); - - /* * Should be a barrier for any external CPU state. */ cpu_init(); - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/