diff options
| -rw-r--r-- | arch/powerpc/Kconfig | 13 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/kfence.h | 33 | ||||
| -rw-r--r-- | arch/powerpc/mm/book3s32/mmu.c | 2 | ||||
| -rw-r--r-- | arch/powerpc/mm/fault.c | 7 | ||||
| -rw-r--r-- | arch/powerpc/mm/init_32.c | 3 | ||||
| -rw-r--r-- | arch/powerpc/mm/mmu_decl.h | 5 | ||||
| -rw-r--r-- | arch/powerpc/mm/nohash/8xx.c | 4 |
7 files changed, 57 insertions, 10 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 386ae12d8523..d46db0bfb998 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -185,6 +185,7 @@ config PPC select HAVE_ARCH_KASAN if PPC32 && PPC_PAGE_SHIFT <= 14 select HAVE_ARCH_KASAN_VMALLOC if PPC32 && PPC_PAGE_SHIFT <= 14 select HAVE_ARCH_KGDB + select HAVE_ARCH_KFENCE if PPC32 select HAVE_ARCH_MMAP_RND_BITS select HAVE_ARCH_MMAP_RND_COMPAT_BITS if COMPAT select HAVE_ARCH_NVRAM_OPS @@ -786,7 +787,7 @@ config THREAD_SHIFT config DATA_SHIFT_BOOL bool "Set custom data alignment" depends on ADVANCED_OPTIONS - depends on STRICT_KERNEL_RWX || DEBUG_PAGEALLOC + depends on STRICT_KERNEL_RWX || DEBUG_PAGEALLOC || KFENCE depends on PPC_BOOK3S_32 || (PPC_8xx && !PIN_TLB_DATA && !STRICT_KERNEL_RWX) help This option allows you to set the kernel data alignment. When @@ -798,13 +799,13 @@ config DATA_SHIFT_BOOL config DATA_SHIFT int "Data shift" if DATA_SHIFT_BOOL default 24 if STRICT_KERNEL_RWX && PPC64 - range 17 28 if (STRICT_KERNEL_RWX || DEBUG_PAGEALLOC) && PPC_BOOK3S_32 - range 19 23 if (STRICT_KERNEL_RWX || DEBUG_PAGEALLOC) && PPC_8xx + range 17 28 if (STRICT_KERNEL_RWX || DEBUG_PAGEALLOC || KFENCE) && PPC_BOOK3S_32 + range 19 23 if (STRICT_KERNEL_RWX || DEBUG_PAGEALLOC || KFENCE) && PPC_8xx default 22 if STRICT_KERNEL_RWX && PPC_BOOK3S_32 - default 18 if DEBUG_PAGEALLOC && PPC_BOOK3S_32 + default 18 if (DEBUG_PAGEALLOC || KFENCE) && PPC_BOOK3S_32 default 23 if STRICT_KERNEL_RWX && PPC_8xx - default 23 if DEBUG_PAGEALLOC && PPC_8xx && PIN_TLB_DATA - default 19 if DEBUG_PAGEALLOC && PPC_8xx + default 23 if (DEBUG_PAGEALLOC || KFENCE) && PPC_8xx && PIN_TLB_DATA + default 19 if (DEBUG_PAGEALLOC || KFENCE) && PPC_8xx default PPC_PAGE_SHIFT help On Book3S 32 (603+), DBATs are used to map kernel text and rodata RO. diff --git a/arch/powerpc/include/asm/kfence.h b/arch/powerpc/include/asm/kfence.h new file mode 100644 index 000000000000..a9846b68c6b9 --- /dev/null +++ b/arch/powerpc/include/asm/kfence.h @@ -0,0 +1,33 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * powerpc KFENCE support. + * + * Copyright (C) 2020 CS GROUP France + */ + +#ifndef __ASM_POWERPC_KFENCE_H +#define __ASM_POWERPC_KFENCE_H + +#include <linux/mm.h> +#include <asm/pgtable.h> + +static inline bool arch_kfence_init_pool(void) +{ + return true; +} + +static inline bool kfence_protect_page(unsigned long addr, bool protect) +{ + pte_t *kpte = virt_to_kpte(addr); + + if (protect) { + pte_update(&init_mm, addr, kpte, _PAGE_PRESENT, 0, 0); + flush_tlb_kernel_range(addr, addr + PAGE_SIZE); + } else { + pte_update(&init_mm, addr, kpte, 0, _PAGE_PRESENT, 0); + } + + return true; +} + +#endif /* __ASM_POWERPC_KFENCE_H */ diff --git a/arch/powerpc/mm/book3s32/mmu.c b/arch/powerpc/mm/book3s32/mmu.c index d7eb266a3f7a..a0db398b5c26 100644 --- a/arch/powerpc/mm/book3s32/mmu.c +++ b/arch/powerpc/mm/book3s32/mmu.c @@ -162,7 +162,7 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) unsigned long border = (unsigned long)__init_begin - PAGE_OFFSET; - if (debug_pagealloc_enabled() || __map_without_bats) { + if (debug_pagealloc_enabled_or_kfence() || __map_without_bats) { pr_debug_once("Read-Write memory mapped without BATs\n"); if (base >= border) return base; diff --git a/arch/powerpc/mm/fault.c b/arch/powerpc/mm/fault.c index bb368257b55c..bea13682c909 100644 --- a/arch/powerpc/mm/fault.c +++ b/arch/powerpc/mm/fault.c @@ -32,6 +32,7 @@ #include <linux/context_tracking.h> #include <linux/hugetlb.h> #include <linux/uaccess.h> +#include <linux/kfence.h> #include <asm/firmware.h> #include <asm/interrupt.h> @@ -418,8 +419,12 @@ static int ___do_page_fault(struct pt_regs *regs, unsigned long address, * take a page fault to a kernel address or a page fault to a user * address outside of dedicated places */ - if (unlikely(!is_user && bad_kernel_fault(regs, error_code, address, is_write))) + if (unlikely(!is_user && bad_kernel_fault(regs, error_code, address, is_write))) { + if (kfence_handle_page_fault(address, is_write, regs)) + return 0; + return SIGSEGV; + } /* * If we're in an interrupt, have no user context or are running diff --git a/arch/powerpc/mm/init_32.c b/arch/powerpc/mm/init_32.c index 02c7db4087cb..3d690be48e84 100644 --- a/arch/powerpc/mm/init_32.c +++ b/arch/powerpc/mm/init_32.c @@ -97,6 +97,9 @@ static void __init MMU_setup(void) if (IS_ENABLED(CONFIG_PPC_8xx)) return; + if (IS_ENABLED(CONFIG_KFENCE)) + __map_without_ltlbs = 1; + if (debug_pagealloc_enabled()) __map_without_ltlbs = 1; diff --git a/arch/powerpc/mm/mmu_decl.h b/arch/powerpc/mm/mmu_decl.h index 998810e68562..7dac910c0b21 100644 --- a/arch/powerpc/mm/mmu_decl.h +++ b/arch/powerpc/mm/mmu_decl.h @@ -185,3 +185,8 @@ void ptdump_check_wx(void); #else static inline void ptdump_check_wx(void) { } #endif + +static inline bool debug_pagealloc_enabled_or_kfence(void) +{ + return IS_ENABLED(CONFIG_KFENCE) || debug_pagealloc_enabled(); +} diff --git a/arch/powerpc/mm/nohash/8xx.c b/arch/powerpc/mm/nohash/8xx.c index 19a3eec1d8c5..71bfdbedacee 100644 --- a/arch/powerpc/mm/nohash/8xx.c +++ b/arch/powerpc/mm/nohash/8xx.c @@ -149,7 +149,7 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) { unsigned long etext8 = ALIGN(__pa(_etext), SZ_8M); unsigned long sinittext = __pa(_sinittext); - bool strict_boundary = strict_kernel_rwx_enabled() || debug_pagealloc_enabled(); + bool strict_boundary = strict_kernel_rwx_enabled() || debug_pagealloc_enabled_or_kfence(); unsigned long boundary = strict_boundary ? sinittext : etext8; unsigned long einittext8 = ALIGN(__pa(_einittext), SZ_8M); @@ -161,7 +161,7 @@ unsigned long __init mmu_mapin_ram(unsigned long base, unsigned long top) return 0; mmu_mapin_ram_chunk(0, boundary, PAGE_KERNEL_TEXT, true); - if (debug_pagealloc_enabled()) { + if (debug_pagealloc_enabled_or_kfence()) { top = boundary; } else { mmu_mapin_ram_chunk(boundary, einittext8, PAGE_KERNEL_TEXT, true); |