From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wm0-f69.google.com (mail-wm0-f69.google.com [74.125.82.69]) by kanga.kvack.org (Postfix) with ESMTP id 5EE3F6B0029 for ; Wed, 28 Mar 2018 04:41:47 -0400 (EDT) Received: by mail-wm0-f69.google.com with SMTP id v21so804198wmh.9 for ; Wed, 28 Mar 2018 01:41:47 -0700 (PDT) Received: from mx.tkos.co.il (guitar.tcltek.co.il. [192.115.133.116]) by mx.google.com with ESMTPS id j126si2270115wmb.12.2018.03.28.01.41.45 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 28 Mar 2018 01:41:45 -0700 (PDT) Date: Wed, 28 Mar 2018 11:41:41 +0300 From: Baruch Siach Subject: Re: [PATCH V4] ZBOOT: fix stack protector in compressed boot phase Message-ID: <20180328084141.vseuroknkrxhraps@sapphire.tkos.co.il> References: <1522226296-3091-1-git-send-email-chenhc@lemote.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1522226296-3091-1-git-send-email-chenhc@lemote.com> Sender: owner-linux-mm@kvack.org List-ID: To: Huacai Chen Cc: Andrew Morton , linux-mips@linux-mips.org, Rich Felker , Russell King , Yoshinori Sato , linux-sh@vger.kernel.org, linux-kernel@vger.kernel.org, Ralf Baechle , linux-mm@kvack.org, stable@vger.kernel.org, James Hogan , linux-arm-kernel@lists.infradead.org Hi Huacai, On Wed, Mar 28, 2018 at 04:38:16PM +0800, Huacai Chen wrote: > Call __stack_chk_guard_setup() in decompress_kernel() is too late that > stack checking always fails for decompress_kernel() itself. So remove > __stack_chk_guard_setup() and initialize __stack_chk_guard before we > call decompress_kernel(). > > Original code comes from ARM but also used for MIPS and SH, so fix them > together. If without this fix, compressed booting of these archs will > fail because stack checking is enabled by default (>=4.16). > > V1 -> V2: Fix build on ARM. > V2 -> V3: Fix build on SuperH. > V3 -> V4: Initialize __stack_chk_guard in C code as a constant. > > Cc: stable@vger.kernel.org > Signed-off-by: Huacai Chen > --- > arch/arm/boot/compressed/head.S | 4 ++++ > arch/arm/boot/compressed/misc.c | 7 ------- > arch/mips/boot/compressed/decompress.c | 7 ------- > arch/mips/boot/compressed/head.S | 4 ++++ > arch/sh/boot/compressed/head_32.S | 8 ++++++++ > arch/sh/boot/compressed/head_64.S | 4 ++++ > arch/sh/boot/compressed/misc.c | 7 ------- > 7 files changed, 20 insertions(+), 21 deletions(-) This diffstat doesn't match the patch below. The patch touches no .S file. baruch > > diff --git a/arch/arm/boot/compressed/misc.c b/arch/arm/boot/compressed/misc.c > index 16a8a80..e8fe51f 100644 > --- a/arch/arm/boot/compressed/misc.c > +++ b/arch/arm/boot/compressed/misc.c > @@ -128,12 +128,7 @@ asmlinkage void __div0(void) > error("Attempting division by 0!"); > } > > -unsigned long __stack_chk_guard; > - > -void __stack_chk_guard_setup(void) > -{ > - __stack_chk_guard = 0x000a0dff; > -} > +const unsigned long __stack_chk_guard = 0x000a0dff; > > void __stack_chk_fail(void) > { > @@ -150,8 +145,6 @@ decompress_kernel(unsigned long output_start, unsigned long free_mem_ptr_p, > { > int ret; > > - __stack_chk_guard_setup(); > - > output_data = (unsigned char *)output_start; > free_mem_ptr = free_mem_ptr_p; > free_mem_end_ptr = free_mem_ptr_end_p; > diff --git a/arch/mips/boot/compressed/decompress.c b/arch/mips/boot/compressed/decompress.c > index fdf99e9..81df904 100644 > --- a/arch/mips/boot/compressed/decompress.c > +++ b/arch/mips/boot/compressed/decompress.c > @@ -76,12 +76,7 @@ void error(char *x) > #include "../../../../lib/decompress_unxz.c" > #endif > > -unsigned long __stack_chk_guard; > - > -void __stack_chk_guard_setup(void) > -{ > - __stack_chk_guard = 0x000a0dff; > -} > +const unsigned long __stack_chk_guard = 0x000a0dff; > > void __stack_chk_fail(void) > { > @@ -92,8 +87,6 @@ void decompress_kernel(unsigned long boot_heap_start) > { > unsigned long zimage_start, zimage_size; > > - __stack_chk_guard_setup(); > - > zimage_start = (unsigned long)(&__image_begin); > zimage_size = (unsigned long)(&__image_end) - > (unsigned long)(&__image_begin); > diff --git a/arch/sh/boot/compressed/misc.c b/arch/sh/boot/compressed/misc.c > index 627ce8e..c15cac9 100644 > --- a/arch/sh/boot/compressed/misc.c > +++ b/arch/sh/boot/compressed/misc.c > @@ -104,12 +104,7 @@ static void error(char *x) > while(1); /* Halt */ > } > > -unsigned long __stack_chk_guard; > - > -void __stack_chk_guard_setup(void) > -{ > - __stack_chk_guard = 0x000a0dff; > -} > +const unsigned long __stack_chk_guard = 0x000a0dff; > > void __stack_chk_fail(void) > { > @@ -130,8 +125,6 @@ void decompress_kernel(void) > { > unsigned long output_addr; > > - __stack_chk_guard_setup(); > - > #ifdef CONFIG_SUPERH64 > output_addr = (CONFIG_MEMORY_START + 0x2000); > #else -- http://baruch.siach.name/blog/ ~. .~ Tk Open Systems =}------------------------------------------------ooO--U--Ooo------------{= - baruch@tkos.co.il - tel: +972.2.679.5364, http://www.tkos.co.il -