From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno =?UTF-8?B?UHLDqW1vbnQ=?= Subject: Re: 3.12 to 3.13 boot regression bisected - still applies to 3.16 Date: Tue, 5 Aug 2014 14:11:42 +0200 Message-ID: <20140805141142.437ecb17@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> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <20140805135130.2d180b69@pluto> Sender: linux-efi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Matt Fleming Cc: P J P , Andrew Morton , linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-efi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-efi@vger.kernel.org On Tue, 5 Aug 2014 13:51:30 +0200 Bruno Pr=C3=A9mont wrote: > On Tue, 5 Aug 2014 10:18:48 +0100 Matt Fleming wrote: > > On Tue, 05 Aug, at 11:13:30AM, Bruno Pr=C3=A9mont wrote: > > >=20 > > > I get at least to just before > > > status =3D efi_call_early(exit_boot_services, handle, key); > > > in eboot.c on line 1310. A efi_printk inserted there is displayed= =2E > >=20 > > 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. >=20 > I am aware that efi_printk() uses boot services! >=20 >=20 > Now I tried out loops at many places and have gotten up to line 340 i= n >=20 > 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). >=20 > So efi_main() returns successfully but the assembler code following i= t > gets something wrong. >=20 > 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=20 355 /* =20 356 * Jump to the relocated address. 357 */ =20 Bruno