From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753233AbaHEMTc (ORCPT ); Tue, 5 Aug 2014 08:19:32 -0400 Received: from smtprelay.restena.lu ([158.64.1.62]:34649 "EHLO smptrelay.restena.lu" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752417AbaHEMTb convert rfc822-to-8bit (ORCPT ); Tue, 5 Aug 2014 08:19:31 -0400 Date: Tue, 5 Aug 2014 14:11:42 +0200 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= To: Matt Fleming Cc: P J P , Andrew Morton , linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: 3.12 to 3.13 boot regression bisected - still applies to 3.16 Message-ID: <20140805141142.437ecb17@pluto> In-Reply-To: <20140805135130.2d180b69@pluto> References: <20140804113435.34ed8c76@pluto> <20140804122728.GH15082@console-pimps.org> <20140804150627.4563b6a7@pluto> <20140804135452.GJ15082@console-pimps.org> <20140805100242.425e1093@pluto> <20140805084542.GM15082@console-pimps.org> <20140805111330.3cf9319f@pluto> <20140805091848.GN15082@console-pimps.org> <20140805135130.2d180b69@pluto> X-Mailer: Claws Mail 3.9.0 (GTK+ 2.24.24; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 5 Aug 2014 13:51:30 +0200 Bruno Prémont wrote: > On Tue, 5 Aug 2014 10:18:48 +0100 Matt Fleming wrote: > > On Tue, 05 Aug, at 11:13:30AM, Bruno Prémont wrote: > > > > > > I get at least to just before > > > status = efi_call_early(exit_boot_services, handle, key); > > > in eboot.c on line 1310. A efi_printk inserted there is displayed. > > > > This is worth pointing out in case you're unaware, but do you know that > > it's not valid to call efi_printk() after ExitBootServices()? Doing so > > will almost certainly cause your machine to fault. > > I am aware that efi_printk() uses boot services! > > > Now I tried out loops at many places and have gotten up to line 340 in > > arch/x86/kernel/head_64.S oops, bad copy&paste, should have been arch/x86/boot/compressed/head_64.S > System reboots within the following assembler instructions (does not > reach line 359). > > So efi_main() returns successfully but the assembler code following it > gets something wrong. > > I'm going to try further to determine which line between 340 and 359 is > the "bad" one. arch/x86/boot/compressed/head_64.S 341 /* 342 * Copy the compressed kernel to the end of our buffer 343 * where decompression in place becomes safe. 344 */ 345 pushq %rsi 346 leaq (_bss-8)(%rip), %rsi 347 leaq (_bss-8)(%rbx), %rdi 348 movq $_bss /* - $startup_32 */, %rcx 349 shrq $3, %rcx 350 std code gets up to here 351 rep movsq this location is never reached but instead system reboots 352 cld 353 popq %rsi 354 355 /* 356 * Jump to the relocated address. 357 */ Bruno