From patchwork Fri Sep 20 09:45:35 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154115 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 36D1314E5 for ; Fri, 20 Sep 2019 09:25:48 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 435F42070C for ; Fri, 20 Sep 2019 09:25:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 435F42070C 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-16893-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 31860 invoked by uid 550); 20 Sep 2019 09:25:39 -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 31828 invoked from network); 20 Sep 2019 09:25:37 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 01/12] powerpc: unify definition of M_IF_NEEDED Date: Fri, 20 Sep 2019 17:45:35 +0800 Message-ID: <20190920094546.44948-2-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected M_IF_NEEDED is defined too many times. Move it to a common place and rename it to MAS2_M_IF_NEEDED which is much readable. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/include/asm/nohash/mmu-book3e.h | 10 ++++++++++ arch/powerpc/kernel/exceptions-64e.S | 12 +----------- arch/powerpc/kernel/fsl_booke_entry_mapping.S | 14 ++------------ arch/powerpc/kernel/misc_64.S | 7 +------ 4 files changed, 14 insertions(+), 29 deletions(-) diff --git a/arch/powerpc/include/asm/nohash/mmu-book3e.h b/arch/powerpc/include/asm/nohash/mmu-book3e.h index 4c9777d256fb..fa3efc2d310f 100644 --- a/arch/powerpc/include/asm/nohash/mmu-book3e.h +++ b/arch/powerpc/include/asm/nohash/mmu-book3e.h @@ -221,6 +221,16 @@ #define TLBILX_T_CLASS2 6 #define TLBILX_T_CLASS3 7 +/* + * The mapping only needs to be cache-coherent on SMP, except on + * Freescale e500mc derivatives where it's also needed for coherent DMA. + */ +#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC) +#define MAS2_M_IF_NEEDED MAS2_M +#else +#define MAS2_M_IF_NEEDED 0 +#endif + #ifndef __ASSEMBLY__ #include diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 1cfb3da4a84a..c5bc09b5e281 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -1342,16 +1342,6 @@ skpinv: addi r6,r6,1 /* Increment */ sync isync -/* - * The mapping only needs to be cache-coherent on SMP, except on - * Freescale e500mc derivatives where it's also needed for coherent DMA. - */ -#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC) -#define M_IF_NEEDED MAS2_M -#else -#define M_IF_NEEDED 0 -#endif - /* 6. Setup KERNELBASE mapping in TLB[0] * * r3 = MAS0 w/TLBSEL & ESEL for the entry we started in @@ -1364,7 +1354,7 @@ skpinv: addi r6,r6,1 /* Increment */ ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l mtspr SPRN_MAS1,r6 - LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | M_IF_NEEDED) + LOAD_REG_IMMEDIATE(r6, PAGE_OFFSET | MAS2_M_IF_NEEDED) mtspr SPRN_MAS2,r6 rlwinm r5,r5,0,0,25 diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S index ea065282b303..f4d3eaae54a9 100644 --- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S +++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S @@ -153,16 +153,6 @@ skpinv: addi r6,r6,1 /* Increment */ tlbivax 0,r9 TLBSYNC -/* - * The mapping only needs to be cache-coherent on SMP, except on - * Freescale e500mc derivatives where it's also needed for coherent DMA. - */ -#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC) -#define M_IF_NEEDED MAS2_M -#else -#define M_IF_NEEDED 0 -#endif - #if defined(ENTRY_MAPPING_BOOT_SETUP) /* 6. Setup KERNELBASE mapping in TLB1[0] */ @@ -171,8 +161,8 @@ skpinv: addi r6,r6,1 /* Increment */ lis r6,(MAS1_VALID|MAS1_IPROT)@h ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l mtspr SPRN_MAS1,r6 - lis r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, M_IF_NEEDED)@h - ori r6,r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, M_IF_NEEDED)@l + lis r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@h + ori r6,r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@l mtspr SPRN_MAS2,r6 mtspr SPRN_MAS3,r8 tlbwe diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index b55a7b4cb543..2062a299a22d 100644 --- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -432,18 +432,13 @@ kexec_create_tlb: rlwimi r9,r10,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r9) */ /* Set up a temp identity mapping v:0 to p:0 and return to it. */ -#if defined(CONFIG_SMP) || defined(CONFIG_PPC_E500MC) -#define M_IF_NEEDED MAS2_M -#else -#define M_IF_NEEDED 0 -#endif mtspr SPRN_MAS0,r9 lis r9,(MAS1_VALID|MAS1_IPROT)@h ori r9,r9,(MAS1_TSIZE(BOOK3E_PAGESZ_1GB))@l mtspr SPRN_MAS1,r9 - LOAD_REG_IMMEDIATE(r9, 0x0 | M_IF_NEEDED) + LOAD_REG_IMMEDIATE(r9, 0x0 | MAS2_M_IF_NEEDED) mtspr SPRN_MAS2,r9 LOAD_REG_IMMEDIATE(r9, 0x0 | MAS3_SR | MAS3_SW | MAS3_SX) From patchwork Fri Sep 20 09:45:36 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154117 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 E4FB614ED for ; Fri, 20 Sep 2019 09:26:04 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 4FA642070C for ; Fri, 20 Sep 2019 09:26:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 4FA642070C 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-16894-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 31928 invoked by uid 550); 20 Sep 2019 09:25:40 -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 31861 invoked from network); 20 Sep 2019 09:25:39 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 02/12] powerpc: move memstart_addr and kernstart_addr to init-common.c Date: Fri, 20 Sep 2019 17:45:36 +0800 Message-ID: <20190920094546.44948-3-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected These two variables are both defined in init_32.c and init_64.c. Move them to init-common.c and make them __ro_after_init. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/mm/init-common.c | 5 +++++ arch/powerpc/mm/init_32.c | 5 ----- arch/powerpc/mm/init_64.c | 5 ----- 3 files changed, 5 insertions(+), 10 deletions(-) diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c index a84da92920f7..e223da482c0c 100644 --- a/arch/powerpc/mm/init-common.c +++ b/arch/powerpc/mm/init-common.c @@ -21,6 +21,11 @@ #include #include +phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull; +EXPORT_SYMBOL_GPL(memstart_addr); +phys_addr_t kernstart_addr __ro_after_init; +EXPORT_SYMBOL_GPL(kernstart_addr); + static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP); diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c index b04896a88d79..872df48ae41b 100644 --- a/arch/powerpc/mm/init_32.c +++ b/arch/powerpc/mm/init_32.c @@ -56,11 +56,6 @@ phys_addr_t total_memory; phys_addr_t total_lowmem; -phys_addr_t memstart_addr = (phys_addr_t)~0ull; -EXPORT_SYMBOL(memstart_addr); -phys_addr_t kernstart_addr; -EXPORT_SYMBOL(kernstart_addr); - #ifdef CONFIG_RELOCATABLE /* Used in __va()/__pa() */ long long virt_phys_offset; diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c index a44f6281ca3a..c836f1269ee7 100644 --- a/arch/powerpc/mm/init_64.c +++ b/arch/powerpc/mm/init_64.c @@ -63,11 +63,6 @@ #include -phys_addr_t memstart_addr = ~0; -EXPORT_SYMBOL_GPL(memstart_addr); -phys_addr_t kernstart_addr; -EXPORT_SYMBOL_GPL(kernstart_addr); - #ifdef CONFIG_SPARSEMEM_VMEMMAP /* * Given an address within the vmemmap, determine the pfn of the page that From patchwork Fri Sep 20 09:45:37 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154121 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 0819716B1 for ; Fri, 20 Sep 2019 09:26:21 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 64E9B208C0 for ; Fri, 20 Sep 2019 09:26:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 64E9B208C0 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-16896-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32034 invoked by uid 550); 20 Sep 2019 09:25:43 -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 31964 invoked from network); 20 Sep 2019 09:25:41 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 03/12] powerpc: introduce kernstart_virt_addr to store the kernel base Date: Fri, 20 Sep 2019 17:45:37 +0800 Message-ID: <20190920094546.44948-4-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Now the kernel base is a fixed value - KERNELBASE. To support KASLR, we need a variable to store the kernel base. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/include/asm/page.h | 2 ++ arch/powerpc/mm/init-common.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 0d52f57fca04..4d32d1b561d6 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -315,6 +315,8 @@ void arch_free_page(struct page *page, int order); struct vm_area_struct; +extern unsigned long kernstart_virt_addr; + #include #endif /* __ASSEMBLY__ */ #include diff --git a/arch/powerpc/mm/init-common.c b/arch/powerpc/mm/init-common.c index e223da482c0c..42ef7a6e6098 100644 --- a/arch/powerpc/mm/init-common.c +++ b/arch/powerpc/mm/init-common.c @@ -25,6 +25,8 @@ phys_addr_t memstart_addr __ro_after_init = (phys_addr_t)~0ull; EXPORT_SYMBOL_GPL(memstart_addr); phys_addr_t kernstart_addr __ro_after_init; EXPORT_SYMBOL_GPL(kernstart_addr); +unsigned long kernstart_virt_addr __ro_after_init = KERNELBASE; +EXPORT_SYMBOL_GPL(kernstart_virt_addr); static bool disable_kuep = !IS_ENABLED(CONFIG_PPC_KUEP); static bool disable_kuap = !IS_ENABLED(CONFIG_PPC_KUAP); From patchwork Fri Sep 20 09:45:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154125 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 B136D14E5 for ; Fri, 20 Sep 2019 09:26:40 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 1B9CB208C0 for ; Fri, 20 Sep 2019 09:26:39 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1B9CB208C0 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-16898-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32128 invoked by uid 550); 20 Sep 2019 09:25:45 -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 31966 invoked from network); 20 Sep 2019 09:25:41 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 04/12] powerpc/fsl_booke/32: introduce create_kaslr_tlb_entry() helper Date: Fri, 20 Sep 2019 17:45:38 +0800 Message-ID: <20190920094546.44948-5-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Add a new helper create_kaslr_tlb_entry() to create a tlb entry by the virtual and physical address. This is a preparation to support boot kernel at a randomized address. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/kernel/head_fsl_booke.S | 35 ++++++++++++++++++++++++++++ arch/powerpc/mm/mmu_decl.h | 1 + 2 files changed, 36 insertions(+) diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index adf0505dbe02..8c1928176ffe 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -1114,6 +1114,41 @@ __secondary_hold_acknowledge: .long -1 #endif +/* + * Create a 64M tlb by address and entry + * r3 - entry + * r4 - virtual address + * r5/r6 - physical address + */ +_GLOBAL(create_kaslr_tlb_entry) + lis r7,0x1000 /* Set MAS0(TLBSEL) = 1 */ + rlwimi r7,r3,16,4,15 /* Setup MAS0 = TLBSEL | ESEL(r6) */ + mtspr SPRN_MAS0,r7 /* Write MAS0 */ + + lis r3,(MAS1_VALID|MAS1_IPROT)@h + ori r3,r3,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l + mtspr SPRN_MAS1,r3 /* Write MAS1 */ + + lis r3,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h + ori r3,r3,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l + and r3,r3,r4 + ori r3,r3,MAS2_M_IF_NEEDED@l + mtspr SPRN_MAS2,r3 /* Write MAS2(EPN) */ + +#ifdef CONFIG_PHYS_64BIT + ori r8,r6,(MAS3_SW|MAS3_SR|MAS3_SX) + mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */ + mtspr SPRN_MAS7,r5 +#else + ori r8,r5,(MAS3_SW|MAS3_SR|MAS3_SX) + mtspr SPRN_MAS3,r8 /* Write MAS3(RPN) */ +#endif + + tlbwe /* Write TLB */ + isync + sync + blr + /* * Create a tlb entry with the same effective and physical address as * the tlb entry used by the current running code. But set the TS to 1. diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 32c1a191c28a..a492ece08f64 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -142,6 +142,7 @@ extern unsigned long calc_cam_sz(unsigned long ram, unsigned long virt, extern void adjust_total_lowmem(void); extern int switch_to_as1(void); extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); +void create_kaslr_tlb_entry(int entry, unsigned long virt, phys_addr_t phys); #endif extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx); From patchwork Fri Sep 20 09:45:39 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154129 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 0179F16B1 for ; Fri, 20 Sep 2019 09:27:02 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 5C4F02086A for ; Fri, 20 Sep 2019 09:27:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5C4F02086A 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-16900-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32218 invoked by uid 550); 20 Sep 2019 09:25:47 -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 31975 invoked from network); 20 Sep 2019 09:25:42 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 05/12] powerpc/fsl_booke/32: introduce reloc_kernel_entry() helper Date: Fri, 20 Sep 2019 17:45:39 +0800 Message-ID: <20190920094546.44948-6-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Add a new helper reloc_kernel_entry() to jump back to the start of the new kernel. After we put the new kernel in a randomized place we can use this new helper to enter the kernel and begin to relocate again. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/kernel/head_fsl_booke.S | 13 +++++++++++++ arch/powerpc/mm/mmu_decl.h | 1 + 2 files changed, 14 insertions(+) diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index 8c1928176ffe..d9f599b01ff1 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -1149,6 +1149,19 @@ _GLOBAL(create_kaslr_tlb_entry) sync blr +/* + * Return to the start of the relocated kernel and run again + * r3 - virtual address of fdt + * r4 - entry of the kernel + */ +_GLOBAL(reloc_kernel_entry) + mfmsr r7 + rlwinm r7, r7, 0, ~(MSR_IS | MSR_DS) + + mtspr SPRN_SRR0,r4 + mtspr SPRN_SRR1,r7 + rfi + /* * Create a tlb entry with the same effective and physical address as * the tlb entry used by the current running code. But set the TS to 1. diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index a492ece08f64..55e86a0bf562 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -143,6 +143,7 @@ extern void adjust_total_lowmem(void); extern int switch_to_as1(void); extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); void create_kaslr_tlb_entry(int entry, unsigned long virt, phys_addr_t phys); +void reloc_kernel_entry(void *fdt, int addr); #endif extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx); From patchwork Fri Sep 20 09:45:40 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154123 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 F037C14E5 for ; Fri, 20 Sep 2019 09:26:29 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 2F17B2086A for ; Fri, 20 Sep 2019 09:26:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2F17B2086A 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-16897-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32102 invoked by uid 550); 20 Sep 2019 09:25:44 -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 31965 invoked from network); 20 Sep 2019 09:25:41 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 06/12] powerpc/fsl_booke/32: implement KASLR infrastructure Date: Fri, 20 Sep 2019 17:45:40 +0800 Message-ID: <20190920094546.44948-7-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected This patch add support to boot kernel from places other than KERNELBASE. Since CONFIG_RELOCATABLE has already supported, what we need to do is map or copy kernel to a proper place and relocate. Freescale Book-E parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1 entries are not suitable to map the kernel directly in a randomized region, so we chose to copy the kernel to a proper place and restart to relocate. The offset of the kernel was not randomized yet(a fixed 64M is set). We will randomize it in the next patch. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Tested-by: Diana Craciun Reviewed-by: Christophe Leroy --- arch/powerpc/Kconfig | 11 ++++ arch/powerpc/include/asm/nohash/mmu-book3e.h | 1 - arch/powerpc/kernel/early_32.c | 5 +- arch/powerpc/kernel/fsl_booke_entry_mapping.S | 15 +++-- arch/powerpc/kernel/head_fsl_booke.S | 13 +++- arch/powerpc/mm/mmu_decl.h | 7 +++ arch/powerpc/mm/nohash/Makefile | 1 + arch/powerpc/mm/nohash/fsl_booke.c | 7 ++- arch/powerpc/mm/nohash/kaslr_booke.c | 62 +++++++++++++++++++ 9 files changed, 106 insertions(+), 16 deletions(-) create mode 100644 arch/powerpc/mm/nohash/kaslr_booke.c diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index d8dcd8820369..4845d572b00f 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -547,6 +547,17 @@ config RELOCATABLE setting can still be useful to bootwrappers that need to know the load address of the kernel (eg. u-boot/mkimage). +config RANDOMIZE_BASE + bool "Randomize the address of the kernel image" + depends on (FSL_BOOKE && FLATMEM && PPC32) + depends on RELOCATABLE + help + Randomizes the virtual address at which the kernel image is + loaded, as a security feature that deters exploit attempts + relying on knowledge of the location of kernel internals. + + If unsure, say Y. + config RELOCATABLE_TEST bool "Test relocatable kernel" depends on (PPC64 && RELOCATABLE) diff --git a/arch/powerpc/include/asm/nohash/mmu-book3e.h b/arch/powerpc/include/asm/nohash/mmu-book3e.h index fa3efc2d310f..b41004664312 100644 --- a/arch/powerpc/include/asm/nohash/mmu-book3e.h +++ b/arch/powerpc/include/asm/nohash/mmu-book3e.h @@ -75,7 +75,6 @@ #define MAS2_E 0x00000001 #define MAS2_WIMGE_MASK 0x0000001f #define MAS2_EPN_MASK(size) (~0 << (size + 10)) -#define MAS2_VAL(addr, size, flags) ((addr) & MAS2_EPN_MASK(size) | (flags)) #define MAS3_RPN 0xFFFFF000 #define MAS3_U0 0x00000200 diff --git a/arch/powerpc/kernel/early_32.c b/arch/powerpc/kernel/early_32.c index 3482118ffe76..6f8689d7ca7b 100644 --- a/arch/powerpc/kernel/early_32.c +++ b/arch/powerpc/kernel/early_32.c @@ -22,7 +22,8 @@ notrace unsigned long __init early_init(unsigned long dt_ptr) unsigned long offset = reloc_offset(); /* First zero the BSS */ - memset(PTRRELOC(&__bss_start), 0, __bss_stop - __bss_start); + if (kernstart_virt_addr == KERNELBASE) + memset(PTRRELOC(&__bss_start), 0, __bss_stop - __bss_start); /* * Identify the CPU type and fix up code sections @@ -32,5 +33,5 @@ notrace unsigned long __init early_init(unsigned long dt_ptr) apply_feature_fixups(); - return KERNELBASE + offset; + return kernstart_virt_addr + offset; } diff --git a/arch/powerpc/kernel/fsl_booke_entry_mapping.S b/arch/powerpc/kernel/fsl_booke_entry_mapping.S index f4d3eaae54a9..8bccce6544b5 100644 --- a/arch/powerpc/kernel/fsl_booke_entry_mapping.S +++ b/arch/powerpc/kernel/fsl_booke_entry_mapping.S @@ -155,23 +155,22 @@ skpinv: addi r6,r6,1 /* Increment */ #if defined(ENTRY_MAPPING_BOOT_SETUP) -/* 6. Setup KERNELBASE mapping in TLB1[0] */ +/* 6. Setup kernstart_virt_addr mapping in TLB1[0] */ lis r6,0x1000 /* Set MAS0(TLBSEL) = TLB1(1), ESEL = 0 */ mtspr SPRN_MAS0,r6 lis r6,(MAS1_VALID|MAS1_IPROT)@h ori r6,r6,(MAS1_TSIZE(BOOK3E_PAGESZ_64M))@l mtspr SPRN_MAS1,r6 - lis r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@h - ori r6,r6,MAS2_VAL(PAGE_OFFSET, BOOK3E_PAGESZ_64M, MAS2_M_IF_NEEDED)@l + lis r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@h + ori r6,r6,MAS2_EPN_MASK(BOOK3E_PAGESZ_64M)@l + and r6,r6,r20 + ori r6,r6,MAS2_M_IF_NEEDED@l mtspr SPRN_MAS2,r6 mtspr SPRN_MAS3,r8 tlbwe -/* 7. Jump to KERNELBASE mapping */ - lis r6,(KERNELBASE & ~0xfff)@h - ori r6,r6,(KERNELBASE & ~0xfff)@l - rlwinm r7,r25,0,0x03ffffff - add r6,r7,r6 +/* 7. Jump to kernstart_virt_addr mapping */ + mr r6,r20 #elif defined(ENTRY_MAPPING_KEXEC_SETUP) /* diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index d9f599b01ff1..838d9d4650c7 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -155,6 +155,8 @@ _ENTRY(_start); */ _ENTRY(__early_start) + LOAD_REG_ADDR_PIC(r20, kernstart_virt_addr) + lwz r20,0(r20) #define ENTRY_MAPPING_BOOT_SETUP #include "fsl_booke_entry_mapping.S" @@ -277,8 +279,8 @@ set_ivor: ori r6, r6, swapper_pg_dir@l lis r5, abatron_pteptrs@h ori r5, r5, abatron_pteptrs@l - lis r4, KERNELBASE@h - ori r4, r4, KERNELBASE@l + lis r3, kernstart_virt_addr@ha + lwz r4, kernstart_virt_addr@l(r3) stw r5, 0(r4) /* Save abatron_pteptrs at a fixed location */ stw r6, 0(r5) @@ -1067,7 +1069,12 @@ __secondary_start: mr r5,r25 /* phys kernel start */ rlwinm r5,r5,0,~0x3ffffff /* aligned 64M */ subf r4,r5,r4 /* memstart_addr - phys kernel start */ - li r5,0 /* no device tree */ + lis r7,KERNELBASE@h + ori r7,r7,KERNELBASE@l + cmpw r20,r7 /* if kernstart_virt_addr != KERNELBASE, randomized */ + beq 2f + li r4,0 +2: li r5,0 /* no device tree */ li r6,0 /* not boot cpu */ bl restore_to_as0 diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 55e86a0bf562..a3a4937c0496 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -144,10 +144,17 @@ extern int switch_to_as1(void); extern void restore_to_as0(int esel, int offset, void *dt_ptr, int bootcpu); void create_kaslr_tlb_entry(int entry, unsigned long virt, phys_addr_t phys); void reloc_kernel_entry(void *fdt, int addr); +extern int is_second_reloc; #endif extern void loadcam_entry(unsigned int index); extern void loadcam_multi(int first_idx, int num, int tmp_idx); +#ifdef CONFIG_RANDOMIZE_BASE +void kaslr_early_init(void *dt_ptr, phys_addr_t size); +#else +static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} +#endif + struct tlbcam { u32 MAS0; u32 MAS1; diff --git a/arch/powerpc/mm/nohash/Makefile b/arch/powerpc/mm/nohash/Makefile index 33b6f6f29d3f..0424f6ce5bd8 100644 --- a/arch/powerpc/mm/nohash/Makefile +++ b/arch/powerpc/mm/nohash/Makefile @@ -8,6 +8,7 @@ obj-$(CONFIG_40x) += 40x.o obj-$(CONFIG_44x) += 44x.o obj-$(CONFIG_PPC_8xx) += 8xx.o obj-$(CONFIG_PPC_FSL_BOOK3E) += fsl_booke.o +obj-$(CONFIG_RANDOMIZE_BASE) += kaslr_booke.o ifdef CONFIG_HUGETLB_PAGE obj-$(CONFIG_PPC_FSL_BOOK3E) += book3e_hugetlbpage.o endif diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c index 556e3cd52a35..2dc27cf88add 100644 --- a/arch/powerpc/mm/nohash/fsl_booke.c +++ b/arch/powerpc/mm/nohash/fsl_booke.c @@ -263,7 +263,8 @@ void setup_initial_memory_limit(phys_addr_t first_memblock_base, int __initdata is_second_reloc; notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start) { - unsigned long base = KERNELBASE; + unsigned long base = kernstart_virt_addr; + phys_addr_t size; kernstart_addr = start; if (is_second_reloc) { @@ -291,7 +292,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start) start &= ~0x3ffffff; base &= ~0x3ffffff; virt_phys_offset = base - start; - early_get_first_memblock_info(__va(dt_ptr), NULL); + early_get_first_memblock_info(__va(dt_ptr), &size); /* * We now get the memstart_addr, then we should check if this * address is the same as what the PAGE_OFFSET map to now. If @@ -316,6 +317,8 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start) /* We should never reach here */ panic("Relocation error"); } + + kaslr_early_init(__va(dt_ptr), size); } #endif #endif diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c new file mode 100644 index 000000000000..29c1567d8d40 --- /dev/null +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -0,0 +1,62 @@ +// SPDX-License-Identifier: GPL-2.0-only +// +// Copyright (C) 2019 Jason Yan + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size, + unsigned long kernel_sz) +{ + /* return a fixed offset of 64M for now */ + return SZ_64M; +} + +/* + * To see if we need to relocate the kernel to a random offset + * void *dt_ptr - address of the device tree + * phys_addr_t size - size of the first memory block + */ +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; + + kernel_sz = (unsigned long)_end - (unsigned long)_stext; + + offset = kaslr_choose_location(dt_ptr, size, kernel_sz); + if (offset == 0) + return; + + kernstart_virt_addr += offset; + kernstart_addr += offset; + + 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); + + /* Create kernel map to relocate in */ + create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); + } + + /* Copy the kernel to it's new location and run */ + memcpy((void *)kernstart_virt_addr, (void *)_stext, kernel_sz); + flush_icache_range(kernstart_virt_addr, kernstart_virt_addr + kernel_sz); + + reloc_kernel_entry(dt_ptr, kernstart_virt_addr); +} From patchwork Fri Sep 20 09:45:41 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154127 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 9662514E5 for ; Fri, 20 Sep 2019 09:26:50 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id C4E812070C for ; Fri, 20 Sep 2019 09:26:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C4E812070C 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-16899-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32167 invoked by uid 550); 20 Sep 2019 09:25:46 -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 31981 invoked from network); 20 Sep 2019 09:25:42 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 07/12] powerpc/fsl_booke/32: randomize the kernel image offset Date: Fri, 20 Sep 2019 17:45:41 +0800 Message-ID: <20190920094546.44948-8-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected After we have the basic support of relocate the kernel in some appropriate place, we can start to randomize the offset now. Entropy is derived from the banner and timer, which will change every build and boot. This not so much safe so additionally the bootloader may pass entropy via the /chosen/kaslr-seed node in device tree. We will use the first 512M of the low memory to randomize the kernel image. The memory will be split in 64M zones. We will use the lower 8 bit of the entropy to decide the index of the 64M zone. Then we chose a 16K aligned offset inside the 64M zone to put the kernel in. We also check if we will overlap with some areas like the dtb area, the initrd area or the crashkernel area. If we cannot find a proper area, kaslr will be disabled and boot from the original kernel. Some pieces of code are derived from arch/x86/boot/compressed/kaslr.c or arch/arm64/kernel/kaslr.c such as rotate_xor(). Credit goes to Kees and Ard. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Diana Craciun Tested-by: Diana Craciun Reviewed-by: Christophe Leroy --- arch/powerpc/mm/nohash/kaslr_booke.c | 325 ++++++++++++++++++++++++++- 1 file changed, 323 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c index 29c1567d8d40..7b238fc2c8a9 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -12,15 +12,336 @@ #include #include #include +#include +#include #include #include +#include #include +#include +#include + +struct regions { + unsigned long pa_start; + unsigned long pa_end; + unsigned long kernel_size; + unsigned long dtb_start; + unsigned long dtb_end; + unsigned long initrd_start; + unsigned long initrd_end; + unsigned long crash_start; + unsigned long crash_end; + int reserved_mem; + int reserved_mem_addr_cells; + int reserved_mem_size_cells; +}; + +/* Simplified build-specific string for starting entropy. */ +static const char build_str[] = UTS_RELEASE " (" LINUX_COMPILE_BY "@" + LINUX_COMPILE_HOST ") (" LINUX_COMPILER ") " UTS_VERSION; + +struct regions __initdata regions; + +static __init void kaslr_get_cmdline(void *fdt) +{ + int node = fdt_path_offset(fdt, "/chosen"); + + early_init_dt_scan_chosen(node, "chosen", 1, boot_command_line); +} + +static unsigned long __init rotate_xor(unsigned long hash, const void *area, + size_t size) +{ + size_t i; + const unsigned long *ptr = area; + + for (i = 0; i < size / sizeof(hash); i++) { + /* Rotate by odd number of bits and XOR. */ + hash = (hash << ((sizeof(hash) * 8) - 7)) | (hash >> 7); + hash ^= ptr[i]; + } + + return hash; +} + +/* Attempt to create a simple starting entropy. This can make it defferent for + * every build but it is still not enough. Stronger entropy should + * be added to make it change for every boot. + */ +static unsigned long __init get_boot_seed(void *fdt) +{ + unsigned long hash = 0; + + hash = rotate_xor(hash, build_str, sizeof(build_str)); + hash = rotate_xor(hash, fdt, fdt_totalsize(fdt)); + + return hash; +} + +static __init u64 get_kaslr_seed(void *fdt) +{ + int node, len; + fdt64_t *prop; + u64 ret; + + node = fdt_path_offset(fdt, "/chosen"); + if (node < 0) + return 0; + + prop = fdt_getprop_w(fdt, node, "kaslr-seed", &len); + if (!prop || len != sizeof(u64)) + return 0; + + ret = fdt64_to_cpu(*prop); + *prop = 0; + return ret; +} + +static __init bool regions_overlap(u32 s1, u32 e1, u32 s2, u32 e2) +{ + return e1 >= s2 && e2 >= s1; +} + +static __init bool overlaps_reserved_region(const void *fdt, u32 start, + u32 end) +{ + int subnode, len, i; + u64 base, size; + + /* check for overlap with /memreserve/ entries */ + for (i = 0; i < fdt_num_mem_rsv(fdt); i++) { + if (fdt_get_mem_rsv(fdt, i, &base, &size) < 0) + continue; + if (regions_overlap(start, end, base, base + size)) + return true; + } + + if (regions.reserved_mem < 0) + return false; + + /* check for overlap with static reservations in /reserved-memory */ + for (subnode = fdt_first_subnode(fdt, regions.reserved_mem); + subnode >= 0; + subnode = fdt_next_subnode(fdt, subnode)) { + const fdt32_t *reg; + u64 rsv_end; + + len = 0; + reg = fdt_getprop(fdt, subnode, "reg", &len); + while (len >= (regions.reserved_mem_addr_cells + + regions.reserved_mem_size_cells)) { + base = fdt32_to_cpu(reg[0]); + if (regions.reserved_mem_addr_cells == 2) + base = (base << 32) | fdt32_to_cpu(reg[1]); + + reg += regions.reserved_mem_addr_cells; + len -= 4 * regions.reserved_mem_addr_cells; + + size = fdt32_to_cpu(reg[0]); + if (regions.reserved_mem_size_cells == 2) + size = (size << 32) | fdt32_to_cpu(reg[1]); + + reg += regions.reserved_mem_size_cells; + len -= 4 * regions.reserved_mem_size_cells; + + if (base >= regions.pa_end) + continue; + + rsv_end = min(base + size, (u64)U32_MAX); + + if (regions_overlap(start, end, base, rsv_end)) + return true; + } + } + return false; +} + +static __init bool overlaps_region(const void *fdt, u32 start, + u32 end) +{ + if (regions_overlap(start, end, __pa(_stext), __pa(_end))) + return true; + + if (regions_overlap(start, end, regions.dtb_start, + regions.dtb_end)) + return true; + + if (regions_overlap(start, end, regions.initrd_start, + regions.initrd_end)) + return true; + + if (regions_overlap(start, end, regions.crash_start, + regions.crash_end)) + return true; + + return overlaps_reserved_region(fdt, start, end); +} + +static void __init get_crash_kernel(void *fdt, unsigned long size) +{ +#ifdef CONFIG_CRASH_CORE + unsigned long long crash_size, crash_base; + int ret; + + ret = parse_crashkernel(boot_command_line, size, &crash_size, + &crash_base); + if (ret != 0 || crash_size == 0) + return; + if (crash_base == 0) + crash_base = KDUMP_KERNELBASE; + + regions.crash_start = (unsigned long)crash_base; + regions.crash_end = (unsigned long)(crash_base + crash_size); + + pr_debug("crash_base=0x%llx crash_size=0x%llx\n", crash_base, crash_size); +#endif +} + +static void __init get_initrd_range(void *fdt) +{ + u64 start, end; + int node, len; + const __be32 *prop; + + node = fdt_path_offset(fdt, "/chosen"); + if (node < 0) + return; + + prop = fdt_getprop(fdt, node, "linux,initrd-start", &len); + if (!prop) + return; + start = of_read_number(prop, len / 4); + + prop = fdt_getprop(fdt, node, "linux,initrd-end", &len); + if (!prop) + return; + end = of_read_number(prop, len / 4); + + regions.initrd_start = (unsigned long)start; + regions.initrd_end = (unsigned long)end; + + pr_debug("initrd_start=0x%llx initrd_end=0x%llx\n", start, end); +} + +static __init unsigned long get_usable_address(const void *fdt, + unsigned long start, + unsigned long offset) +{ + unsigned long pa; + unsigned long pa_end; + + for (pa = offset; (long)pa > (long)start; pa -= SZ_16K) { + pa_end = pa + regions.kernel_size; + if (overlaps_region(fdt, pa, pa_end)) + continue; + + return pa; + } + return 0; +} + +static __init void get_cell_sizes(const void *fdt, int node, int *addr_cells, + int *size_cells) +{ + const int *prop; + int len; + + /* + * Retrieve the #address-cells and #size-cells properties + * from the 'node', or use the default if not provided. + */ + *addr_cells = *size_cells = 1; + + prop = fdt_getprop(fdt, node, "#address-cells", &len); + if (len == 4) + *addr_cells = fdt32_to_cpu(*prop); + prop = fdt_getprop(fdt, node, "#size-cells", &len); + if (len == 4) + *size_cells = fdt32_to_cpu(*prop); +} + +static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long index, + unsigned long offset) +{ + unsigned long koffset = 0; + unsigned long start; + + while ((long)index >= 0) { + offset = memstart_addr + index * SZ_64M + offset; + start = memstart_addr + index * SZ_64M; + koffset = get_usable_address(dt_ptr, start, offset); + if (koffset) + break; + index--; + } + + if (koffset != 0) + koffset -= memstart_addr; + + return koffset; +} static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size, unsigned long kernel_sz) { - /* return a fixed offset of 64M for now */ - return SZ_64M; + unsigned long offset, random; + unsigned long ram, linear_sz; + u64 seed; + unsigned long index; + + kaslr_get_cmdline(dt_ptr); + + random = get_boot_seed(dt_ptr); + + seed = get_tb() << 32; + seed ^= get_tb(); + random = rotate_xor(random, &seed, sizeof(seed)); + + /* + * Retrieve (and wipe) the seed from the FDT + */ + seed = get_kaslr_seed(dt_ptr); + if (seed) + random = rotate_xor(random, &seed, sizeof(seed)); + else + pr_warn("KASLR: No safe seed for randomizing the kernel base.\n"); + + ram = min_t(phys_addr_t, __max_low_memory, size); + ram = map_mem_in_cams(ram, CONFIG_LOWMEM_CAM_NUM, true); + linear_sz = min_t(unsigned long, ram, SZ_512M); + + /* If the linear size is smaller than 64M, do not randmize */ + if (linear_sz < SZ_64M) + return 0; + + /* check for a reserved-memory node and record its cell sizes */ + regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory"); + if (regions.reserved_mem >= 0) + get_cell_sizes(dt_ptr, regions.reserved_mem, + ®ions.reserved_mem_addr_cells, + ®ions.reserved_mem_size_cells); + + regions.pa_start = memstart_addr; + regions.pa_end = memstart_addr + linear_sz; + regions.dtb_start = __pa(dt_ptr); + regions.dtb_end = __pa(dt_ptr) + fdt_totalsize(dt_ptr); + regions.kernel_size = kernel_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); } /* From patchwork Fri Sep 20 09:45:42 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154137 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 0177014E5 for ; Fri, 20 Sep 2019 09:27:35 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 5E5412070C for ; Fri, 20 Sep 2019 09:27:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5E5412070C 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-16903-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32395 invoked by uid 550); 20 Sep 2019 09:25:50 -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 32173 invoked from network); 20 Sep 2019 09:25:46 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 08/12] powerpc/fsl_booke/kaslr: clear the original kernel if randomized Date: Fri, 20 Sep 2019 17:45:42 +0800 Message-ID: <20190920094546.44948-9-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected The original kernel still exists in the memory, clear it now. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/mm/mmu_decl.h | 2 ++ arch/powerpc/mm/nohash/fsl_booke.c | 1 + arch/powerpc/mm/nohash/kaslr_booke.c | 11 +++++++++++ 3 files changed, 14 insertions(+) diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index a3a4937c0496..565731475a07 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -151,8 +151,10 @@ extern void loadcam_multi(int first_idx, int num, int tmp_idx); #ifdef CONFIG_RANDOMIZE_BASE void kaslr_early_init(void *dt_ptr, phys_addr_t size); +void kaslr_late_init(void); #else static inline void kaslr_early_init(void *dt_ptr, phys_addr_t size) {} +static inline void kaslr_late_init(void) {} #endif struct tlbcam { diff --git a/arch/powerpc/mm/nohash/fsl_booke.c b/arch/powerpc/mm/nohash/fsl_booke.c index 2dc27cf88add..b4eb06ceb189 100644 --- a/arch/powerpc/mm/nohash/fsl_booke.c +++ b/arch/powerpc/mm/nohash/fsl_booke.c @@ -269,6 +269,7 @@ notrace void __init relocate_init(u64 dt_ptr, phys_addr_t start) kernstart_addr = start; if (is_second_reloc) { virt_phys_offset = PAGE_OFFSET - memstart_addr; + kaslr_late_init(); return; } diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c index 7b238fc2c8a9..aa1b60c782e7 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -381,3 +381,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) reloc_kernel_entry(dt_ptr, kernstart_virt_addr); } + +void __init kaslr_late_init(void) +{ + /* If randomized, clear the original kernel */ + if (kernstart_virt_addr != KERNELBASE) { + unsigned long kernel_sz; + + kernel_sz = (unsigned long)_end - kernstart_virt_addr; + memzero_explicit((void *)KERNELBASE, kernel_sz); + } +} From patchwork Fri Sep 20 09:45:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154143 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 4646C14E5 for ; Fri, 20 Sep 2019 09:27:56 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id A26022070C for ; Fri, 20 Sep 2019 09:27:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A26022070C 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-16905-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32493 invoked by uid 550); 20 Sep 2019 09:25:52 -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 32174 invoked from network); 20 Sep 2019 09:25:46 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 09/12] powerpc/fsl_booke/kaslr: support nokaslr cmdline parameter Date: Fri, 20 Sep 2019 17:45:43 +0800 Message-ID: <20190920094546.44948-10-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected One may want to disable kaslr when boot, so provide a cmdline parameter 'nokaslr' to support this. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Diana Craciun Tested-by: Diana Craciun Reviewed-by: Christophe Leroy --- arch/powerpc/mm/nohash/kaslr_booke.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c index aa1b60c782e7..4a75f2d9bf0e 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -281,6 +281,11 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long index return koffset; } +static inline __init bool kaslr_disabled(void) +{ + return strstr(boot_command_line, "nokaslr") != NULL; +} + static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size, unsigned long kernel_sz) { @@ -290,6 +295,8 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size unsigned long index; kaslr_get_cmdline(dt_ptr); + if (kaslr_disabled()) + return 0; random = get_boot_seed(dt_ptr); From patchwork Fri Sep 20 09:45:44 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154133 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 21AA214E5 for ; Fri, 20 Sep 2019 09:27:13 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 7DC5E2070C for ; Fri, 20 Sep 2019 09:27:12 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DC5E2070C 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-16901-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32338 invoked by uid 550); 20 Sep 2019 09:25:49 -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 32171 invoked from network); 20 Sep 2019 09:25:46 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 10/12] powerpc/fsl_booke/kaslr: dump out kernel offset information on panic Date: Fri, 20 Sep 2019 17:45:44 +0800 Message-ID: <20190920094546.44948-11-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected When kaslr is enabled, the kernel offset is different for every boot. This brings some difficult to debug the kernel. Dump out the kernel offset when panic so that we can easily debug the kernel. This code is derived from x86/arm64 which has similar functionality. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun --- arch/powerpc/include/asm/page.h | 5 +++++ arch/powerpc/kernel/setup-common.c | 20 ++++++++++++++++++++ 2 files changed, 25 insertions(+) diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 4d32d1b561d6..b34b9cdd91f1 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -317,6 +317,11 @@ struct vm_area_struct; extern unsigned long kernstart_virt_addr; +static inline unsigned long kaslr_offset(void) +{ + return kernstart_virt_addr - KERNELBASE; +} + #include #endif /* __ASSEMBLY__ */ #include diff --git a/arch/powerpc/kernel/setup-common.c b/arch/powerpc/kernel/setup-common.c index 1f8db666468d..ba1a34ab218a 100644 --- a/arch/powerpc/kernel/setup-common.c +++ b/arch/powerpc/kernel/setup-common.c @@ -715,8 +715,28 @@ static struct notifier_block ppc_panic_block = { .priority = INT_MIN /* may not return; must be done last */ }; +/* + * Dump out kernel offset information on panic. + */ +static int dump_kernel_offset(struct notifier_block *self, unsigned long v, + void *p) +{ + pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n", + kaslr_offset(), KERNELBASE); + + return 0; +} + +static struct notifier_block kernel_offset_notifier = { + .notifier_call = dump_kernel_offset +}; + void __init setup_panic(void) { + if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && kaslr_offset() > 0) + atomic_notifier_chain_register(&panic_notifier_list, + &kernel_offset_notifier); + /* PPC64 always does a hard irq disable in its panic handler */ if (!IS_ENABLED(CONFIG_PPC64) && !ppc_md.panic) return; From patchwork Fri Sep 20 09:45:45 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154141 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 BE75314E5 for ; Fri, 20 Sep 2019 09:27:45 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 281022070C for ; Fri, 20 Sep 2019 09:27:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 281022070C 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-16904-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32470 invoked by uid 550); 20 Sep 2019 09:25:51 -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 32175 invoked from network); 20 Sep 2019 09:25:46 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 11/12] powerpc/fsl_booke/kaslr: export offset in VMCOREINFO ELF notes Date: Fri, 20 Sep 2019 17:45:45 +0800 Message-ID: <20190920094546.44948-12-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Like all other architectures such as x86 or arm64, include KASLR offset in VMCOREINFO ELF notes to assist in debugging. After this, we can use crash --kaslr option to parse vmcore generated from a kaslr kernel. Note: The crash tool needs to support --kaslr too. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook --- arch/powerpc/kernel/machine_kexec.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/powerpc/kernel/machine_kexec.c b/arch/powerpc/kernel/machine_kexec.c index c4ed328a7b96..078fe3d76feb 100644 --- a/arch/powerpc/kernel/machine_kexec.c +++ b/arch/powerpc/kernel/machine_kexec.c @@ -86,6 +86,7 @@ void arch_crash_save_vmcoreinfo(void) VMCOREINFO_STRUCT_SIZE(mmu_psize_def); VMCOREINFO_OFFSET(mmu_psize_def, shift); #endif + vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset()); } /* From patchwork Fri Sep 20 09:45:46 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11154135 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 2648F14ED for ; Fri, 20 Sep 2019 09:27:24 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 830472070C for ; Fri, 20 Sep 2019 09:27:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 830472070C 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-16902-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 32372 invoked by uid 550); 20 Sep 2019 09:25:50 -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 32172 invoked from network); 20 Sep 2019 09:25:46 -0000 From: Jason Yan To: , , , , , , , , CC: , , , , , , , Jason Yan Subject: [PATCH v7 12/12] powerpc/fsl_booke/32: Document KASLR implementation Date: Fri, 20 Sep 2019 17:45:46 +0800 Message-ID: <20190920094546.44948-13-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20190920094546.44948-1-yanaijie@huawei.com> References: <20190920094546.44948-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected Add document to explain how we implement KASLR for fsl_booke32. Signed-off-by: Jason Yan Cc: Diana Craciun Cc: Michael Ellerman Cc: Christophe Leroy Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Nicholas Piggin Cc: Kees Cook --- Documentation/powerpc/kaslr-booke32.rst | 42 +++++++++++++++++++++++++ 1 file changed, 42 insertions(+) create mode 100644 Documentation/powerpc/kaslr-booke32.rst diff --git a/Documentation/powerpc/kaslr-booke32.rst b/Documentation/powerpc/kaslr-booke32.rst new file mode 100644 index 000000000000..8b259fdfdf03 --- /dev/null +++ b/Documentation/powerpc/kaslr-booke32.rst @@ -0,0 +1,42 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=========================== +KASLR for Freescale BookE32 +=========================== + +The word KASLR stands for Kernel Address Space Layout Randomization. + +This document tries to explain the implementation of the KASLR for +Freescale BookE32. KASLR is a security feature that deters exploit +attempts relying on knowledge of the location of kernel internals. + +Since CONFIG_RELOCATABLE has already supported, what we need to do is +map or copy kernel to a proper place and relocate. Freescale Book-E +parts expect lowmem to be mapped by fixed TLB entries(TLB1). The TLB1 +entries are not suitable to map the kernel directly in a randomized +region, so we chose to copy the kernel to a proper place and restart to +relocate. + +Entropy is derived from the banner and timer base, which will change every +build and boot. This not so much safe so additionally the bootloader may +pass entropy via the /chosen/kaslr-seed node in device tree. + +We will use the first 512M of the low memory to randomize the kernel +image. The memory will be split in 64M zones. We will use the lower 8 +bit of the entropy to decide the index of the 64M zone. Then we chose a +16K aligned offset inside the 64M zone to put the kernel in:: + + KERNELBASE + + |--> 64M <--| + | | + +---------------+ +----------------+---------------+ + | |....| |kernel| | | + +---------------+ +----------------+---------------+ + | | + |-----> offset <-----| + + kernstart_virt_addr + +To enable KASLR, set CONFIG_RANDOMIZE_BASE = y. If KASLR is enable and you +want to disable it at runtime, add "nokaslr" to the kernel cmdline.