From patchwork Thu Feb 6 02:58:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jason Yan X-Patchwork-Id: 11367553 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 F320D138D for ; Thu, 6 Feb 2020 03:00:27 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 3B598214AF for ; Thu, 6 Feb 2020 03:00:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B598214AF 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-17690-patchwork-kernel-hardening=patchwork.kernel.org@lists.openwall.com Received: (qmail 1127 invoked by uid 550); 6 Feb 2020 02:59:53 -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 32602 invoked from network); 6 Feb 2020 02:59:50 -0000 From: Jason Yan To: , , , , , , , , , CC: , , Jason Yan Subject: [PATCH v3 3/6] powerpc/fsl_booke/64: implement KASLR for fsl_booke64 Date: Thu, 6 Feb 2020 10:58:22 +0800 Message-ID: <20200206025825.22934-4-yanaijie@huawei.com> X-Mailer: git-send-email 2.17.2 In-Reply-To: <20200206025825.22934-1-yanaijie@huawei.com> References: <20200206025825.22934-1-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 | 7 ++++++ arch/powerpc/kernel/setup_64.c | 4 +++- arch/powerpc/mm/mmu_decl.h | 16 +++++++------- arch/powerpc/mm/nohash/kaslr_booke.c | 33 +++++++++++++++++++++++++--- 6 files changed, 59 insertions(+), 13 deletions(-) diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index c150a9d49343..754aeb96bb1c 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -568,7 +568,7 @@ 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..c1c05b8684ca 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) + lwz 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..744624140fb8 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -104,6 +104,13 @@ __secondary_hold_acknowledge: .8byte 0x0 #ifdef CONFIG_RELOCATABLE +#ifdef CONFIG_RANDOMIZE_BASE + . = 0x58 + .globl __kaslr_offset +__kaslr_offset: +DEFINE_FIXED_SYMBOL(__kaslr_offset) + .long 0 +#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 6104917a282d..a16b970a8d1a 100644 --- a/arch/powerpc/kernel/setup_64.c +++ b/arch/powerpc/kernel/setup_64.c @@ -66,7 +66,7 @@ #include #include #include - +#include #include "setup.h" int spinning_secondaries; @@ -300,6 +300,8 @@ 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 3e1c85c7d10b..bbd721d1e3d7 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -147,14 +147,6 @@ 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 +156,14 @@ 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 07b036e98353..c6f5c1db1394 100644 --- a/arch/powerpc/mm/nohash/kaslr_booke.c +++ b/arch/powerpc/mm/nohash/kaslr_booke.c @@ -231,7 +231,7 @@ static __init unsigned long get_usable_address(const void *fdt, 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 -= SZ_64K) { pa_end = pa + regions.kernel_size; if (overlaps_region(fdt, pa, pa_end)) continue; @@ -265,14 +265,14 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long rando { unsigned long koffset = 0; unsigned long start; - unsigned long index; unsigned long offset; +#ifdef CONFIG_PPC32 /* * Decide which 64M we want to start * Only use the low 8 bits of the random seed */ - index = random & 0xFF; + unsigned long index = random & 0xFF; index %= regions.linear_sz / SZ_64M; /* Decide offset inside 64M */ @@ -287,6 +287,15 @@ static unsigned long __init kaslr_legal_offset(void *dt_ptr, unsigned long rando break; index--; } +#else + /* Decide kernel offset inside 1G */ + offset = random % (SZ_1G - regions.kernel_size); + offset = round_down(offset, SZ_64K); + + start = memstart_addr; + offset = memstart_addr + offset; + koffset = get_usable_address(dt_ptr, start, offset); +#endif if (koffset != 0) koffset -= memstart_addr; @@ -325,6 +334,7 @@ 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 +342,7 @@ 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"); @@ -363,6 +374,17 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) unsigned long offset; unsigned long kernel_sz; +#ifdef CONFIG_PPC64 + unsigned int *__kaslr_offset = (unsigned int *)(KERNELBASE + 0x58); + unsigned int *__run_at_load = (unsigned int *)(KERNELBASE + 0x5c); + + if (*__run_at_load == 1) + return; + + /* Setup flat device-tree pointer */ + initial_boot_params = dt_ptr; +#endif + kernel_sz = (unsigned long)_end - (unsigned long)_stext; offset = kaslr_choose_location(dt_ptr, size, kernel_sz); @@ -372,6 +394,7 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) kernstart_virt_addr += offset; kernstart_addr += offset; +#ifdef CONFIG_PPC32 is_second_reloc = 1; if (offset >= SZ_64M) { @@ -381,6 +404,10 @@ notrace void __init kaslr_early_init(void *dt_ptr, phys_addr_t size) /* 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; +#endif /* Copy the kernel to it's new location and run */ memcpy((void *)kernstart_virt_addr, (void *)_stext, kernel_sz);