From 8054df0570588e22007a8be6fa7615462389f27f Mon Sep 17 00:00:00 2001 From: Jason Yan Date: Fri, 20 Sep 2019 17:45:35 +0800 Subject: powerpc: unify definition of M_IF_NEEDED 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 Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun Signed-off-by: Scott Wood Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/nohash/mmu-book3e.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/powerpc/include') 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 -- cgit v1.2.3 From 39f4b7bf7571a9c6529b0bb3de49c9bb0998f194 Mon Sep 17 00:00:00 2001 From: Jason Yan Date: Fri, 20 Sep 2019 17:45:37 +0800 Subject: powerpc: introduce kernstart_virt_addr to store the kernel base 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 Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun Signed-off-by: Scott Wood Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/page.h | 2 ++ arch/powerpc/mm/init-common.c | 2 ++ 2 files changed, 4 insertions(+) (limited to 'arch/powerpc/include') diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index c8bb14ff4713..88fa53f89f5a 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -325,6 +325,8 @@ 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); -- cgit v1.2.3 From 2b0e86cc5de6dabadc2d64cefa429fc227c8a756 Mon Sep 17 00:00:00 2001 From: Jason Yan Date: Fri, 20 Sep 2019 17:45:40 +0800 Subject: powerpc/fsl_booke/32: implement KASLR infrastructure 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 Tested-by: Diana Craciun Reviewed-by: Christophe Leroy Signed-off-by: Scott Wood [mpe: Use PTRRELOC() in early_init()] Signed-off-by: Michael Ellerman --- arch/powerpc/Kconfig | 11 +++++ arch/powerpc/include/asm/nohash/mmu-book3e.h | 1 - arch/powerpc/kernel/early_32.c | 9 ++-- 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, 109 insertions(+), 17 deletions(-) create mode 100644 arch/powerpc/mm/nohash/kaslr_booke.c (limited to 'arch/powerpc/include') diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 3e56c9c2f16e..4c4a0fcd1674 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -551,6 +551,17 @@ 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..ef2ad4945904 100644 --- a/arch/powerpc/kernel/early_32.c +++ b/arch/powerpc/kernel/early_32.c @@ -19,10 +19,13 @@ */ notrace unsigned long __init early_init(unsigned long dt_ptr) { - unsigned long offset = reloc_offset(); + unsigned long kva, offset = reloc_offset(); + + kva = *PTRRELOC(&kernstart_virt_addr); /* First zero the BSS */ - memset(PTRRELOC(&__bss_start), 0, __bss_stop - __bss_start); + if (kva == KERNELBASE) + memset(PTRRELOC(&__bss_start), 0, __bss_stop - __bss_start); /* * Identify the CPU type and fix up code sections @@ -32,5 +35,5 @@ notrace unsigned long __init early_init(unsigned long dt_ptr) apply_feature_fixups(); - return KERNELBASE + offset; + return kva + 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 bbfd185fb99a..ae06c5675abb 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -141,10 +141,17 @@ 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); +} -- cgit v1.2.3 From 921a79b7802078fab3787c7eae561536906cb8f3 Mon Sep 17 00:00:00 2001 From: Jason Yan Date: Fri, 20 Sep 2019 17:45:44 +0800 Subject: powerpc/fsl_booke/kaslr: dump out kernel offset information on panic 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 Reviewed-by: Christophe Leroy Reviewed-by: Diana Craciun Tested-by: Diana Craciun Signed-off-by: Scott Wood Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/page.h | 5 +++++ arch/powerpc/kernel/setup-common.c | 20 ++++++++++++++++++++ 2 files changed, 25 insertions(+) (limited to 'arch/powerpc/include') diff --git a/arch/powerpc/include/asm/page.h b/arch/powerpc/include/asm/page.h index 88fa53f89f5a..f2f3ed5a8969 100644 --- a/arch/powerpc/include/asm/page.h +++ b/arch/powerpc/include/asm/page.h @@ -327,6 +327,11 @@ 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 25aaa3903000..488f1eecc0de 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; -- cgit v1.2.3