From patchwork Fri Mar 6 06:40:30 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11423221 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 D438114B7 for ; Fri, 6 Mar 2020 06:42:29 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 1DA822084E for ; Fri, 6 Mar 2020 06:42:28 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1DA822084E 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-18095-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 23742 invoked by uid 550); 6 Mar 2020 06:42:12 -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 22479 invoked from network); 6 Mar 2020 06:42:08 -0000 From: Jason Yan To: , , , , , , , , , CC: , , , Jason Yan Subject: [PATCH v4 3/6] powerpc/fsl_booke/64: implement KASLR for fsl_booke64 Date: Fri, 6 Mar 2020 14:40:30 +0800 Message-ID: <20200306064033.3398-4-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200306064033.3398-1-yanaijie@huawei.com> References: <20200306064033.3398-1-yanaijie@huawei.com> MIME-Version: 1.0 X-Originating-IP: [10.175.124.28] X-CFilter-Loop: Reflected The implementation for Freescale BookE64 is similar as BookE32. One difference is that Freescale BookE64 set up a TLB mapping of 1G during booting. Another difference is that ppc64 needs the kernel to be 64K-aligned. So we can randomize the kernel in this 1G mapping and make it 64K-aligned. This can save some code to creat another TLB map at early boot. The disadvantage is that we only have about 1G/64K = 16384 slots to put the kernel in. To support secondary cpu boot up, a variable __kaslr_offset was added in first_256B section. This can help secondary cpu get the kaslr offset before the 1:1 mapping has been setup. 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/Kconfig | 2 +- arch/powerpc/kernel/exceptions-64e.S | 10 ++++ arch/powerpc/kernel/head_64.S | 6 +++ arch/powerpc/kernel/setup_64.c | 3 ++ arch/powerpc/mm/mmu_decl.h | 20 ++++---- arch/powerpc/mm/nohash/kaslr_booke.c | 72 +++++++++++++++++++--------- 6 files changed, 80 insertions(+), 33 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 497b7d0b2d7e..0c76601fdd59 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -564,7 +564,7 @@ config RELOCATABLE config RANDOMIZE_BASE bool "Randomize the address of the kernel image" - depends on (FSL_BOOKE && FLATMEM && PPC32) + depends on (PPC_FSL_BOOK3E && FLATMEM) depends on RELOCATABLE help Randomizes the virtual address at which the kernel image is diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 1b9b174bee86..260cf1f1e71c 100644 --- a/arch/powerpc/kernel/exceptions-64e.S +++ b/arch/powerpc/kernel/exceptions-64e.S @@ -1378,6 +1378,7 @@ skpinv: addi r6,r6,1 /* Increment */ 1: mflr r6 addi r6,r6,(2f - 1b) tovirt(r6,r6) + add r6,r6,r19 lis r7,MSR_KERNEL@h ori r7,r7,MSR_KERNEL@l mtspr SPRN_SRR0,r6 @@ -1400,6 +1401,7 @@ skpinv: addi r6,r6,1 /* Increment */ /* We translate LR and return */ tovirt(r8,r8) + add r8,r8,r19 mtlr r8 blr @@ -1528,6 +1530,7 @@ a2_tlbinit_code_end: */ _GLOBAL(start_initialization_book3e) mflr r28 + li r19, 0 /* First, we need to setup some initial TLBs to map the kernel * text, data and bss at PAGE_OFFSET. We don't have a real mode @@ -1570,6 +1573,12 @@ _GLOBAL(book3e_secondary_core_init) cmplwi r4,0 bne 2f + li r19, 0 +#ifdef CONFIG_RANDOMIZE_BASE + LOAD_REG_ADDR_PIC(r19, __kaslr_offset) + ld r19,0(r19) + rlwinm r19,r19,0,0,5 +#endif /* Setup TLB for this core */ bl initial_tlb_book3e @@ -1602,6 +1611,7 @@ _GLOBAL(book3e_secondary_core_init) lis r3,PAGE_OFFSET@highest sldi r3,r3,32 or r28,r28,r3 + add r28,r28,r19 1: mtlr r28 blr diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index ad79fddb974d..454129a3c259 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -104,6 +104,12 @@ __secondary_hold_acknowledge: .8byte 0x0 #ifdef CONFIG_RELOCATABLE +#ifdef CONFIG_RANDOMIZE_BASE + .globl __kaslr_offset +__kaslr_offset: + .8byte 0x0 +#endif + /* This flag is set to 1 by a loader if the kernel should run * at the loaded address instead of the linked address. This * is used by kexec-tools to keep the the kdump kernel in the diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c index e05e6dd67ae6..836e202dfd5b 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -67,6 +67,7 @@ #include #include +#include #include "setup.h" int spinning_secondaries; @@ -300,6 +301,8 @@ void __init early_setup(unsigned long dt_ptr) /* Enable early debugging if any specified (see udbg.h) */ udbg_early_init(); + kaslr_early_init(__va(dt_ptr), 0); + udbg_printf(" -> %s(), dt_ptr: 0x%lx\n", __func__, dt_ptr); /* diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 605129b5ccdf..6efbd7fd88a4 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -139,22 +139,16 @@ 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); +#endif void create_kaslr_tlb_entry(int entry, unsigned long virt, phys_addr_t phys); extern int is_second_reloc; -#endif +extern unsigned long __kaslr_offset; +extern unsigned int __run_at_load; void reloc_kernel_entry(void *fdt, long addr); 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); -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 { u32 MAS0; u32 MAS1; @@ -164,6 +158,14 @@ struct tlbcam { }; #endif +#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 + #if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_FSL_BOOKE) || defined(CONFIG_PPC_8xx) /* 6xx have BATS */ /* FSL_BOOKE have TLBCAM */ diff --git a/arch/powerpc/mm/nohash/kaslr_booke.c b/arch/powerpc/mm/nohash/kaslr_booke.c index 6ebff31fefcc..bf60f956dc91 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -228,10 +228,11 @@ static __init unsigned long get_usable_address(const void *fdt, unsigned long start, unsigned long offset) { + unsigned long unit = IS_ENABLED(CONFIG_PPC32) ? SZ_16K : SZ_64K; unsigned long pa; unsigned long pa_end; - for (pa = offset; (long)pa > (long)start; pa -= SZ_16K) { + for (pa = offset; (long)pa > (long)start; pa -= unit) { pa_end = pa + regions.kernel_size; if (overlaps_region(fdt, pa, pa_end)) continue; @@ -268,24 +269,34 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long rando 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); + if (IS_ENABLED(CONFIG_PPC32)) { + /* + * 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; + start = memstart_addr + index * SZ_64M; + koffset = get_usable_address(dt_ptr, start, offset); + if (koffset) + break; + index--; + } + } else { + /* Decide kernel offset inside 1G */ + offset = random % (SZ_1G - regions.kernel_size); + offset = round_down(offset, SZ_64K); - while ((long)index >= 0) { - offset = memstart_addr + index * SZ_64M + offset; - start = memstart_addr + index * SZ_64M; + start = memstart_addr; + offset = memstart_addr + offset; koffset = get_usable_address(dt_ptr, start, offset); - if (koffset) - break; - index--; } if (koffset != 0) @@ -325,6 +336,7 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size else pr_warn("KASLR: No safe seed for randomizing the kernel base.\n"); +#ifdef CONFIG_PPC32 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); @@ -332,6 +344,7 @@ static unsigned long __init kaslr_choose_location(void *dt_ptr, phys_addr_t size /* If the linear size is smaller than 64M, do not randmize */ if (linear_sz < SZ_64M) return 0; +#endif /* check for a reserved-memory node and record its cell sizes */ regions.reserved_mem = fdt_path_offset(dt_ptr, "/reserved-memory"); @@ -365,6 +378,14 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) unsigned long offset; unsigned long kernel_sz; + if (IS_ENABLED(CONFIG_PPC64)) { + if (__run_at_load == 1) + return; + + /* Setup flat device-tree pointer */ + initial_boot_params = dt_ptr; + } + kernel_sz = (unsigned long)_end - (unsigned long)_stext; offset = kaslr_choose_location(dt_ptr, size, kernel_sz); @@ -374,14 +395,19 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) kernstart_virt_addr += offset; kernstart_addr += offset; - is_second_reloc = 1; + if (IS_ENABLED(CONFIG_PPC32)) { + 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); + 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); + /* Create kernel map to relocate in */ + create_kaslr_tlb_entry(1, tlb_virt, tlb_phys); + } + } else { + __kaslr_offset = kernstart_virt_addr - KERNELBASE; + __run_at_load = 1; } /* Copy the kernel to it's new location and run */