From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756079AbbGFXHF (ORCPT ); Mon, 6 Jul 2015 19:07:05 -0400 Received: from smtp.outflux.net ([198.145.64.163]:40597 "EHLO smtp.outflux.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754191AbbGFXGz (ORCPT ); Mon, 6 Jul 2015 19:06:55 -0400 Date: Mon, 6 Jul 2015 16:06:20 -0700 From: Kees Cook To: linux-kernel@vger.kernel.org Cc: Josh Triplett , Joe Perches , Yinghai Lu , Andy Lutomirski , Vivek Goyal , "H. Peter Anvin" , Andi Kleen , Thomas Gleixner , Ingo Molnar , x86@kernel.org, Borislav Petkov , Junjie Mao , Jiri Kosina , Jan Beulich , Andrew Morton , Andrey Ryabinin Subject: [PATCH][RESEND] x86, boot: add hex output for debugging Message-ID: <20150706230620.GA17501@www.outflux.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-HELO: www.outflux.net Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This is useful for reporting various addresses or other values while debugging early boot, for example, the recent kernel image size vs kernel run size. For example, when CONFIG_X86_VERBOSE_BOOTUP is set, this is now visible at boot time: early console in setup code early console in decompress_kernel input_data: 0x0000000001e1526e input_len: 0x0000000000732236 output: 0x0000000001000000 output_len: 0x0000000001535640 run_size: 0x00000000021fb000 KASLR using RDTSC... Signed-off-by: Kees Cook --- There was some discussion around this patch when I sent it before, but ultimately, concensus seemed to be that it was fine as-is (e.g. full printf and macros are over-kill, reduction of print infrastructure is a separate issue). Thoughts? --- arch/x86/boot/compressed/misc.c | 24 ++++++++++++++++++++++++ arch/x86/boot/compressed/misc.h | 11 +++++++++++ 2 files changed, 35 insertions(+) diff --git a/arch/x86/boot/compressed/misc.c b/arch/x86/boot/compressed/misc.c index a107b935e22f..f63797942bb5 100644 --- a/arch/x86/boot/compressed/misc.c +++ b/arch/x86/boot/compressed/misc.c @@ -220,6 +220,23 @@ void __putstr(const char *s) outb(0xff & (pos >> 1), vidport+1); } +void __puthex(unsigned long value) +{ + char alpha[2] = "0"; + int bits; + + for (bits = sizeof(value) * 8 - 4; bits >= 0; bits -= 4) { + unsigned long digit = (value >> bits) & 0xf; + + if (digit < 0xA) + alpha[0] = '0' + digit; + else + alpha[0] = 'a' + (digit - 0xA); + + __putstr(alpha); + } +} + static void error(char *x) { error_putstr("\n\n"); @@ -399,6 +416,13 @@ asmlinkage __visible void *decompress_kernel(void *rmode, memptr heap, free_mem_ptr = heap; /* Heap */ free_mem_end_ptr = heap + BOOT_HEAP_SIZE; + /* Report initial kernel position details. */ + debug_putaddr(input_data); + debug_putaddr(input_len); + debug_putaddr(output); + debug_putaddr(output_len); + debug_putaddr(run_size); + /* * The memory hole needed for the kernel is the larger of either * the entire decompressed kernel plus relocation table, or the diff --git a/arch/x86/boot/compressed/misc.h b/arch/x86/boot/compressed/misc.h index 805d25ca5f1d..3783dc3e10b3 100644 --- a/arch/x86/boot/compressed/misc.h +++ b/arch/x86/boot/compressed/misc.h @@ -34,16 +34,27 @@ extern memptr free_mem_ptr; extern memptr free_mem_end_ptr; extern struct boot_params *real_mode; /* Pointer to real-mode data */ void __putstr(const char *s); +void __puthex(unsigned long value); #define error_putstr(__x) __putstr(__x) +#define error_puthex(__x) __puthex(__x) #ifdef CONFIG_X86_VERBOSE_BOOTUP #define debug_putstr(__x) __putstr(__x) +#define debug_puthex(__x) __puthex(__x) +#define debug_putaddr(__x) { \ + debug_putstr(#__x ": 0x"); \ + debug_puthex((unsigned long)(__x)); \ + debug_putstr("\n"); \ + } #else static inline void debug_putstr(const char *s) { } +static inline void debug_puthex(const char *s) +{ } +#define debug_putaddr(x) /* */ #endif -- 1.9.1 -- Kees Cook Chrome OS Security