From 784a46618f634973a17535b7d3d03cd4ebc0ccbd Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Wed, 23 Jun 2021 14:02:05 +0200 Subject: [PATCH] x86/pkeys: Move read_pkru() and write_pkru() write_pkru() was originally used just to write to the PKRU register. It was mercifully short and sweet and was not out of place in pgtable.h with some other pkey-related code. But, later work included a requirement to also modify the task XSAVE buffer when updating the register. This really is more related to the XSAVE architecture than to paging. Move the read/write_pkru() to asm/pkru.h. pgtable.h won't miss them. Signed-off-by: Dave Hansen Signed-off-by: Thomas Gleixner Signed-off-by: Borislav Petkov Link: https://lkml.kernel.org/r/20210623121455.102647114@linutronix.de --- arch/x86/include/asm/fpu/xstate.h | 1 + arch/x86/include/asm/pgtable.h | 57 +----------------------------------- arch/x86/include/asm/pkru.h | 61 +++++++++++++++++++++++++++++++++++++++ arch/x86/kernel/process_64.c | 1 + arch/x86/kvm/svm/sev.c | 1 + arch/x86/kvm/x86.c | 1 + arch/x86/mm/pkeys.c | 1 + 7 files changed, 67 insertions(+), 56 deletions(-) create mode 100644 arch/x86/include/asm/pkru.h diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 7de2384..5764cbe3 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -6,6 +6,7 @@ #include #include +#include #include /* Bit 63 of XCR0 is reserved for future expansion */ diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index b1099f2..ec0d8e1 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -23,7 +23,7 @@ #ifndef __ASSEMBLY__ #include -#include +#include #include #include @@ -126,35 +126,6 @@ static inline int pte_dirty(pte_t pte) return pte_flags(pte) & _PAGE_DIRTY; } - -static inline u32 read_pkru(void) -{ - if (boot_cpu_has(X86_FEATURE_OSPKE)) - return rdpkru(); - return 0; -} - -static inline void write_pkru(u32 pkru) -{ - struct pkru_state *pk; - - if (!boot_cpu_has(X86_FEATURE_OSPKE)) - return; - - pk = get_xsave_addr(¤t->thread.fpu.state.xsave, XFEATURE_PKRU); - - /* - * The PKRU value in xstate needs to be in sync with the value that is - * written to the CPU. The FPU restore on return to userland would - * otherwise load the previous value again. - */ - fpregs_lock(); - if (pk) - pk->pkru = pkru; - __write_pkru(pkru); - fpregs_unlock(); -} - static inline int pte_young(pte_t pte) { return pte_flags(pte) & _PAGE_ACCESSED; @@ -1360,32 +1331,6 @@ static inline pmd_t pmd_swp_clear_uffd_wp(pmd_t pmd) } #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_WP */ -#define PKRU_AD_BIT 0x1 -#define PKRU_WD_BIT 0x2 -#define PKRU_BITS_PER_PKEY 2 - -#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS -extern u32 init_pkru_value; -#else -#define init_pkru_value 0 -#endif - -static inline bool __pkru_allows_read(u32 pkru, u16 pkey) -{ - int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY; - return !(pkru & (PKRU_AD_BIT << pkru_pkey_bits)); -} - -static inline bool __pkru_allows_write(u32 pkru, u16 pkey) -{ - int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY; - /* - * Access-disable disables writes too so we need to check - * both bits here. - */ - return !(pkru & ((PKRU_AD_BIT|PKRU_WD_BIT) << pkru_pkey_bits)); -} - static inline u16 pte_flags_pkey(unsigned long pte_flags) { #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS diff --git a/arch/x86/include/asm/pkru.h b/arch/x86/include/asm/pkru.h new file mode 100644 index 0000000..35ffcfd --- /dev/null +++ b/arch/x86/include/asm/pkru.h @@ -0,0 +1,61 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_PKRU_H +#define _ASM_X86_PKRU_H + +#include + +#define PKRU_AD_BIT 0x1 +#define PKRU_WD_BIT 0x2 +#define PKRU_BITS_PER_PKEY 2 + +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS +extern u32 init_pkru_value; +#else +#define init_pkru_value 0 +#endif + +static inline bool __pkru_allows_read(u32 pkru, u16 pkey) +{ + int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY; + return !(pkru & (PKRU_AD_BIT << pkru_pkey_bits)); +} + +static inline bool __pkru_allows_write(u32 pkru, u16 pkey) +{ + int pkru_pkey_bits = pkey * PKRU_BITS_PER_PKEY; + /* + * Access-disable disables writes too so we need to check + * both bits here. + */ + return !(pkru & ((PKRU_AD_BIT|PKRU_WD_BIT) << pkru_pkey_bits)); +} + +static inline u32 read_pkru(void) +{ + if (boot_cpu_has(X86_FEATURE_OSPKE)) + return rdpkru(); + return 0; +} + +static inline void write_pkru(u32 pkru) +{ + struct pkru_state *pk; + + if (!boot_cpu_has(X86_FEATURE_OSPKE)) + return; + + pk = get_xsave_addr(¤t->thread.fpu.state.xsave, XFEATURE_PKRU); + + /* + * The PKRU value in xstate needs to be in sync with the value that is + * written to the CPU. The FPU restore on return to userland would + * otherwise load the previous value again. + */ + fpregs_lock(); + if (pk) + pk->pkru = pkru; + __write_pkru(pkru); + fpregs_unlock(); +} + +#endif diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c index d08307d..4651ab0 100644 --- a/arch/x86/kernel/process_64.c +++ b/arch/x86/kernel/process_64.c @@ -41,6 +41,7 @@ #include #include +#include #include #include #include diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c index 8d36f0c..62926f1 100644 --- a/arch/x86/kvm/svm/sev.c +++ b/arch/x86/kvm/svm/sev.c @@ -19,6 +19,7 @@ #include #include +#include #include #include "x86.h" diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index 6f651b9..07f7888 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -65,6 +65,7 @@ #include #include #include +#include #include #include /* Ugh! */ #include diff --git a/arch/x86/mm/pkeys.c b/arch/x86/mm/pkeys.c index a840ac7..a02cfcf 100644 --- a/arch/x86/mm/pkeys.c +++ b/arch/x86/mm/pkeys.c @@ -10,6 +10,7 @@ #include /* boot_cpu_has, ... */ #include /* vma_pkey() */ +#include /* read/write_pkru() */ int __execute_only_pkey(struct mm_struct *mm) { -- 2.7.4