From patchwork Wed Feb 5 02:55:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11365691 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6D61813A4 for ; Wed, 5 Feb 2020 02:57:00 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 649632082E for ; Wed, 5 Feb 2020 02:56:58 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 649632082E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=huawei.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-17662-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 3927 invoked by uid 550); 5 Feb 2020 02:56:51 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Delivered-To: mailing list kernel-hardening@lists.openwall.com Received: (qmail 3868 invoked from network); 5 Feb 2020 02:56:50 -0000 From: Jason Yan To: , , , , , , , , , CC: , , Jason Yan Subject: [PATCH v2 1/6] powerpc/fsl_booke/kaslr: refactor kaslr_legal_offset() and kaslr_early_init() Date: Wed, 5 Feb 2020 10:55:22 +0800 Message-ID: <20200205025527.28640-2-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200205025527.28640-1-yanaijie@huawei.com> References: <20200205025527.28640-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Some code refactor in kaslr_legal_offset() and kaslr_early_init(). No functional change. This is a preparation for KASLR fsl_booke64. Signed-off-by: Jason Yan Cc: Scott Wood Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook --- arch/powerpc/mm/nohash/kaslr_booke.c | 40 ++++++++++++++-------------- 1 file changed, 20 insertions(+), 20 deletions(-) diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c index 4a75f2d9bf0e..07b036e98353 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -25,6 +25,7 @@ struct regions { unsigned long pa_start; unsigned long pa_end; unsigned long kernel_size; + unsigned long linear_sz; unsigned long dtb_start; unsigned long dtb_end; unsigned long initrd_start; @@ -260,11 +261,23 @@ static __init void get_cell_sizes(const void *fdt, int node, int *addr_cells, *size_cells = fdt32_to_cpu(*prop); } -static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long index, - unsigned long offset) +static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long random) { unsigned long koffset = 0; unsigned long start; + unsigned long index; + unsigned long offset; + + /* + * Decide which 64M we want to start + * Only use the low 8 bits of the random seed + */ + index = random & 0xFF; + index %= regions.linear_sz / SZ_64M; + + /* Decide offset inside 64M */ + offset = random % (SZ_64M - regions.kernel_size); + offset = round_down(offset, SZ_16K); while ((long)index >= 0) { offset = memstart_addr + index * SZ_64M + offset; @@ -289,10 +302,9 @@ static inline __init bool kaslr_disabled(void) static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size, unsigned long kernel_sz) { - unsigned long offset, random; + unsigned long random; unsigned long ram, linear_sz; u64 seed; - unsigned long index; kaslr_get_cmdline(dt_ptr); if (kaslr_disabled()) @@ -333,22 +345,12 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size regions.dtb_start = __pa(dt_ptr); regions.dtb_end = __pa(dt_ptr) + fdt_totalsize(dt_ptr); regions.kernel_size = kernel_sz; + regions.linear_sz = linear_sz; get_initrd_range(dt_ptr); get_crash_kernel(dt_ptr, ram); - /* - * Decide which 64M we want to start - * Only use the low 8 bits of the random seed - */ - index = random & 0xFF; - index %= linear_sz / SZ_64M; - - /* Decide offset inside 64M */ - offset = random % (SZ_64M - kernel_sz); - offset = round_down(offset, SZ_16K); - - return kaslr_legal_offset(dt_ptr, index, offset); + return kaslr_legal_offset(dt_ptr, random); } /* @@ -358,8 +360,6 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size */ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) { - unsigned long tlb_virt; - phys_addr_t tlb_phys; unsigned long offset; unsigned long kernel_sz; @@ -375,8 +375,8 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) is_second_reloc = 1; if (offset >= SZ_64M) { - tlb_virt = round_down(kernstart_virt_addr, SZ_64M); - tlb_phys = round_down(kernstart_addr, SZ_64M); + unsigned long tlb_virt = round_down(kernstart_virt_addr, SZ_64M); + phys_addr_t tlb_phys = round_down(kernstart_addr, SZ_64M); /* Create kernel map to relocate in */ create_kaslr_tlb_entry(1, tlb_virt, tlb_phys);