Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751577AbWHaCMY (ORCPT ); Wed, 30 Aug 2006 22:12:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751579AbWHaCMY (ORCPT ); Wed, 30 Aug 2006 22:12:24 -0400 Received: from liaag2af.mx.compuserve.com ([149.174.40.157]:55226 "EHLO liaag2af.mx.compuserve.com") by vger.kernel.org with ESMTP id S1751576AbWHaCMX (ORCPT ); Wed, 30 Aug 2006 22:12:23 -0400 Date: Wed, 30 Aug 2006 22:05:46 -0400 From: Chuck Ebbert <76306.1226@compuserve.com> Subject: Re: [PATCH][RFC] exception processing in early boot To: Andi Kleen Cc: pageexec , linux-kernel , Willy Tarreau Message-ID: <200608302209_MC3-1-C9E0-28B7@compuserve.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3394 Lines: 139 In-Reply-To: <200608301830.40994.ak@suse.de> On Wed, 30 Aug 2006 18:30:40 +0200, Andi Kleen wrote: > It would be better to separate exceptions from interrupts here. > A spurious interrupt is not necessarily fatal, just an exception is. > > But I went with the simpler patch with some changes now > (added PANIC to the message etc.) This is already in -mm: ================================================================================ From: Chuck Ebbert <76306.1226@compuserve.com> Add early i386 fault handlers with debug information for common faults. Handles: divide error invalid opcode protection fault page fault Also adds code to detect early recursive/multiple faults and halt the system when they happen (taken from x86_64.) Signed-off-by: Chuck Ebbert <76306.1226@compuserve.com> Cc: Andi Kleen Cc: Ingo Molnar Signed-off-by: Andrew Morton --- arch/i386/kernel/head.S | 67 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) diff -puN arch/i386/kernel/head.S~i386-early-fault-handler arch/i386/kernel/head.S --- a/arch/i386/kernel/head.S~i386-early-fault-handler +++ a/arch/i386/kernel/head.S @@ -371,8 +371,65 @@ rp_sidt: addl $8,%edi dec %ecx jne rp_sidt + +.macro set_early_handler handler,trapno + lea \handler,%edx + movl $(__KERNEL_CS << 16),%eax + movw %dx,%ax + movw $0x8E00,%dx /* interrupt gate - dpl=0, present */ + lea idt_table,%edi + movl %eax,8*\trapno(%edi) + movl %edx,8*\trapno+4(%edi) +.endm + + set_early_handler handler=early_divide_err,trapno=0 + set_early_handler handler=early_illegal_opcode,trapno=6 + set_early_handler handler=early_protection_fault,trapno=13 + set_early_handler handler=early_page_fault,trapno=14 + ret +early_divide_err: + xor %edx,%edx + pushl $0 /* fake errcode */ + jmp early_fault + +early_illegal_opcode: + movl $6,%edx + pushl $0 /* fake errcode */ + jmp early_fault + +early_protection_fault: + movl $13,%edx + jmp early_fault + +early_page_fault: + movl $14,%edx + jmp early_fault + +early_fault: + cld +#ifdef CONFIG_PRINTK + movl $(__KERNEL_DS),%eax + movl %eax,%ds + movl %eax,%es + cmpl $2,early_recursion_flag + je hlt_loop + incl early_recursion_flag + movl %cr2,%eax + pushl %eax + pushl %edx /* trapno */ + pushl $fault_msg +#ifdef CONFIG_EARLY_PRINTK + call early_printk +#else + call printk +#endif +#endif +hlt_loop: + hlt + jmp hlt_loop + /* This is the default interrupt "handler" :-) */ ALIGN ignore_int: @@ -386,6 +443,9 @@ ignore_int: movl $(__KERNEL_DS),%eax movl %eax,%ds movl %eax,%es + cmpl $2,early_recursion_flag + je hlt_loop + incl early_recursion_flag pushl 16(%esp) pushl 24(%esp) pushl 32(%esp) @@ -431,9 +491,16 @@ ENTRY(stack_start) ready: .byte 0 +early_recursion_flag: + .long 0 + int_msg: .asciz "Unknown interrupt or fault at EIP %p %p %p\n" +fault_msg: + .ascii "Int %d: CR2 %p err %p EIP %p CS %p flags %p\n" + .asciz "Stack: %p %p %p %p %p %p %p %p\n" + /* * The IDT and GDT 'descriptors' are a strange 48-bit object * only used by the lidt and lgdt instructions. They are not _ -- Chuck - 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/