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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:27:49 +0000 |
commit | ace9429bb58fd418f0c81d4c2835699bddf6bde6 (patch) | |
tree | b2d64bc10158fdd5497876388cd68142ca374ed3 /arch/x86/include/asm/mmu_context.h | |
parent | Initial commit. (diff) | |
download | linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.tar.xz linux-ace9429bb58fd418f0c81d4c2835699bddf6bde6.zip |
Adding upstream version 6.6.15.upstream/6.6.15
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'arch/x86/include/asm/mmu_context.h')
-rw-r--r-- | arch/x86/include/asm/mmu_context.h | 265 |
1 files changed, 265 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h new file mode 100644 index 0000000000..8dac45a2c7 --- /dev/null +++ b/arch/x86/include/asm/mmu_context.h @@ -0,0 +1,265 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _ASM_X86_MMU_CONTEXT_H +#define _ASM_X86_MMU_CONTEXT_H + +#include <asm/desc.h> +#include <linux/atomic.h> +#include <linux/mm_types.h> +#include <linux/pkeys.h> + +#include <trace/events/tlb.h> + +#include <asm/tlbflush.h> +#include <asm/paravirt.h> +#include <asm/debugreg.h> +#include <asm/gsseg.h> + +extern atomic64_t last_mm_ctx_id; + +#ifdef CONFIG_PERF_EVENTS +DECLARE_STATIC_KEY_FALSE(rdpmc_never_available_key); +DECLARE_STATIC_KEY_FALSE(rdpmc_always_available_key); +void cr4_update_pce(void *ignored); +#endif + +#ifdef CONFIG_MODIFY_LDT_SYSCALL +/* + * ldt_structs can be allocated, used, and freed, but they are never + * modified while live. + */ +struct ldt_struct { + /* + * Xen requires page-aligned LDTs with special permissions. This is + * needed to prevent us from installing evil descriptors such as + * call gates. On native, we could merge the ldt_struct and LDT + * allocations, but it's not worth trying to optimize. + */ + struct desc_struct *entries; + unsigned int nr_entries; + + /* + * If PTI is in use, then the entries array is not mapped while we're + * in user mode. The whole array will be aliased at the addressed + * given by ldt_slot_va(slot). We use two slots so that we can allocate + * and map, and enable a new LDT without invalidating the mapping + * of an older, still-in-use LDT. + * + * slot will be -1 if this LDT doesn't have an alias mapping. + */ + int slot; +}; + +/* + * Used for LDT copy/destruction. + */ +static inline void init_new_context_ldt(struct mm_struct *mm) +{ + mm->context.ldt = NULL; + init_rwsem(&mm->context.ldt_usr_sem); +} +int ldt_dup_context(struct mm_struct *oldmm, struct mm_struct *mm); +void destroy_context_ldt(struct mm_struct *mm); +void ldt_arch_exit_mmap(struct mm_struct *mm); +#else /* CONFIG_MODIFY_LDT_SYSCALL */ +static inline void init_new_context_ldt(struct mm_struct *mm) { } +static inline int ldt_dup_context(struct mm_struct *oldmm, + struct mm_struct *mm) +{ + return 0; +} +static inline void destroy_context_ldt(struct mm_struct *mm) { } +static inline void ldt_arch_exit_mmap(struct mm_struct *mm) { } +#endif + +#ifdef CONFIG_MODIFY_LDT_SYSCALL +extern void load_mm_ldt(struct mm_struct *mm); +extern void switch_ldt(struct mm_struct *prev, struct mm_struct *next); +#else +static inline void load_mm_ldt(struct mm_struct *mm) +{ + clear_LDT(); +} +static inline void switch_ldt(struct mm_struct *prev, struct mm_struct *next) +{ + DEBUG_LOCKS_WARN_ON(preemptible()); +} +#endif + +#ifdef CONFIG_ADDRESS_MASKING +static inline unsigned long mm_lam_cr3_mask(struct mm_struct *mm) +{ + return mm->context.lam_cr3_mask; +} + +static inline void dup_lam(struct mm_struct *oldmm, struct mm_struct *mm) +{ + mm->context.lam_cr3_mask = oldmm->context.lam_cr3_mask; + mm->context.untag_mask = oldmm->context.untag_mask; +} + +#define mm_untag_mask mm_untag_mask +static inline unsigned long mm_untag_mask(struct mm_struct *mm) +{ + return mm->context.untag_mask; +} + +static inline void mm_reset_untag_mask(struct mm_struct *mm) +{ + mm->context.untag_mask = -1UL; +} + +#define arch_pgtable_dma_compat arch_pgtable_dma_compat +static inline bool arch_pgtable_dma_compat(struct mm_struct *mm) +{ + return !mm_lam_cr3_mask(mm) || + test_bit(MM_CONTEXT_FORCE_TAGGED_SVA, &mm->context.flags); +} +#else + +static inline unsigned long mm_lam_cr3_mask(struct mm_struct *mm) +{ + return 0; +} + +static inline void dup_lam(struct mm_struct *oldmm, struct mm_struct *mm) +{ +} + +static inline void mm_reset_untag_mask(struct mm_struct *mm) +{ +} +#endif + +#define enter_lazy_tlb enter_lazy_tlb +extern void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk); + +/* + * Init a new mm. Used on mm copies, like at fork() + * and on mm's that are brand-new, like at execve(). + */ +#define init_new_context init_new_context +static inline int init_new_context(struct task_struct *tsk, + struct mm_struct *mm) +{ + mutex_init(&mm->context.lock); + + mm->context.ctx_id = atomic64_inc_return(&last_mm_ctx_id); + atomic64_set(&mm->context.tlb_gen, 0); + +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS + if (cpu_feature_enabled(X86_FEATURE_OSPKE)) { + /* pkey 0 is the default and allocated implicitly */ + mm->context.pkey_allocation_map = 0x1; + /* -1 means unallocated or invalid */ + mm->context.execute_only_pkey = -1; + } +#endif + mm_reset_untag_mask(mm); + init_new_context_ldt(mm); + return 0; +} + +#define destroy_context destroy_context +static inline void destroy_context(struct mm_struct *mm) +{ + destroy_context_ldt(mm); +} + +extern void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk); + +extern void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk); +#define switch_mm_irqs_off switch_mm_irqs_off + +#define activate_mm(prev, next) \ +do { \ + paravirt_enter_mmap(next); \ + switch_mm((prev), (next), NULL); \ +} while (0); + +#ifdef CONFIG_X86_32 +#define deactivate_mm(tsk, mm) \ +do { \ + loadsegment(gs, 0); \ +} while (0) +#else +#define deactivate_mm(tsk, mm) \ +do { \ + shstk_free(tsk); \ + load_gs_index(0); \ + loadsegment(fs, 0); \ +} while (0) +#endif + +static inline void arch_dup_pkeys(struct mm_struct *oldmm, + struct mm_struct *mm) +{ +#ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS + if (!cpu_feature_enabled(X86_FEATURE_OSPKE)) + return; + + /* Duplicate the oldmm pkey state in mm: */ + mm->context.pkey_allocation_map = oldmm->context.pkey_allocation_map; + mm->context.execute_only_pkey = oldmm->context.execute_only_pkey; +#endif +} + +static inline int arch_dup_mmap(struct mm_struct *oldmm, struct mm_struct *mm) +{ + arch_dup_pkeys(oldmm, mm); + paravirt_enter_mmap(mm); + dup_lam(oldmm, mm); + return ldt_dup_context(oldmm, mm); +} + +static inline void arch_exit_mmap(struct mm_struct *mm) +{ + paravirt_arch_exit_mmap(mm); + ldt_arch_exit_mmap(mm); +} + +#ifdef CONFIG_X86_64 +static inline bool is_64bit_mm(struct mm_struct *mm) +{ + return !IS_ENABLED(CONFIG_IA32_EMULATION) || + !test_bit(MM_CONTEXT_UPROBE_IA32, &mm->context.flags); +} +#else +static inline bool is_64bit_mm(struct mm_struct *mm) +{ + return false; +} +#endif + +static inline void arch_unmap(struct mm_struct *mm, unsigned long start, + unsigned long end) +{ +} + +/* + * We only want to enforce protection keys on the current process + * because we effectively have no access to PKRU for other + * processes or any way to tell *which * PKRU in a threaded + * process we could use. + * + * So do not enforce things if the VMA is not from the current + * mm, or if we are in a kernel thread. + */ +static inline bool arch_vma_access_permitted(struct vm_area_struct *vma, + bool write, bool execute, bool foreign) +{ + /* pkeys never affect instruction fetches */ + if (execute) + return true; + /* allow access if the VMA is not one from this process */ + if (foreign || vma_is_foreign(vma)) + return true; + return __pkru_allows_pkey(vma_pkey(vma), write); +} + +unsigned long __get_current_cr3_fast(void); + +#include <asm-generic/mmu_context.h> + +#endif /* _ASM_X86_MMU_CONTEXT_H */ |