diff options
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/cpufeatures.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/mmu_context.h | 5 | ||||
| -rw-r--r-- | arch/x86/include/asm/nospec-branch.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable-2level.h | 9 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable-2level_types.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable-3level.h | 7 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable-3level_types.h | 6 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable.h | 87 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable_32.h | 2 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable_32_types.h | 9 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable_64.h | 89 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable_64_types.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/pgtable_types.h | 28 | ||||
| -rw-r--r-- | arch/x86/include/asm/processor-flags.h | 8 | ||||
| -rw-r--r-- | arch/x86/include/asm/pti.h | 3 | ||||
| -rw-r--r-- | arch/x86/include/asm/sections.h | 1 | ||||
| -rw-r--r-- | arch/x86/include/asm/switch_to.h | 16 |
17 files changed, 169 insertions, 110 deletions
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index 5701f5cecd31..2687cd8e8d58 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -219,6 +219,7 @@ #define X86_FEATURE_IBPB ( 7*32+26) /* Indirect Branch Prediction Barrier */ #define X86_FEATURE_STIBP ( 7*32+27) /* Single Thread Indirect Branch Predictors */ #define X86_FEATURE_ZEN ( 7*32+28) /* "" CPU is AMD family 0x17 (Zen) */ +#define X86_FEATURE_IBRS_ENHANCED ( 7*32+29) /* Enhanced IBRS */ /* Virtualization flags: Linux defined, word 8 */ #define X86_FEATURE_TPR_SHADOW ( 8*32+ 0) /* Intel TPR Shadow */ diff --git a/arch/x86/include/asm/mmu_context.h b/arch/x86/include/asm/mmu_context.h index bbc796eb0a3b..eeeb9289c764 100644 --- a/arch/x86/include/asm/mmu_context.h +++ b/arch/x86/include/asm/mmu_context.h @@ -71,12 +71,7 @@ struct ldt_struct { static inline void *ldt_slot_va(int slot) { -#ifdef CONFIG_X86_64 return (void *)(LDT_BASE_ADDR + LDT_SLOT_STRIDE * slot); -#else - BUG(); - return (void *)fix_to_virt(FIX_HOLE); -#endif } /* diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h index f6f6c63da62f..fd2a8c1b88bc 100644 --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -214,7 +214,7 @@ enum spectre_v2_mitigation { SPECTRE_V2_RETPOLINE_MINIMAL_AMD, SPECTRE_V2_RETPOLINE_GENERIC, SPECTRE_V2_RETPOLINE_AMD, - SPECTRE_V2_IBRS, + SPECTRE_V2_IBRS_ENHANCED, }; /* The Speculative Store Bypass disable variants */ diff --git a/arch/x86/include/asm/pgtable-2level.h b/arch/x86/include/asm/pgtable-2level.h index 685ffe8a0eaf..c399ea5eea41 100644 --- a/arch/x86/include/asm/pgtable-2level.h +++ b/arch/x86/include/asm/pgtable-2level.h @@ -19,6 +19,9 @@ static inline void native_set_pte(pte_t *ptep , pte_t pte) static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd) { +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pmd.pud.p4d.pgd = pti_set_user_pgtbl(&pmdp->pud.p4d.pgd, pmd.pud.p4d.pgd); +#endif *pmdp = pmd; } @@ -58,6 +61,9 @@ static inline pte_t native_ptep_get_and_clear(pte_t *xp) #ifdef CONFIG_SMP static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp) { +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pti_set_user_pgtbl(&xp->pud.p4d.pgd, __pgd(0)); +#endif return __pmd(xchg((pmdval_t *)xp, 0)); } #else @@ -67,6 +73,9 @@ static inline pmd_t native_pmdp_get_and_clear(pmd_t *xp) #ifdef CONFIG_SMP static inline pud_t native_pudp_get_and_clear(pud_t *xp) { +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pti_set_user_pgtbl(&xp->p4d.pgd, __pgd(0)); +#endif return __pud(xchg((pudval_t *)xp, 0)); } #else diff --git a/arch/x86/include/asm/pgtable-2level_types.h b/arch/x86/include/asm/pgtable-2level_types.h index f982ef808e7e..6deb6cd236e3 100644 --- a/arch/x86/include/asm/pgtable-2level_types.h +++ b/arch/x86/include/asm/pgtable-2level_types.h @@ -35,4 +35,7 @@ typedef union { #define PTRS_PER_PTE 1024 +/* This covers all VMSPLIT_* and VMSPLIT_*_OPT variants */ +#define PGD_KERNEL_START (CONFIG_PAGE_OFFSET >> PGDIR_SHIFT) + #endif /* _ASM_X86_PGTABLE_2LEVEL_DEFS_H */ diff --git a/arch/x86/include/asm/pgtable-3level.h b/arch/x86/include/asm/pgtable-3level.h index f24df59c40b2..f2ca3139ca22 100644 --- a/arch/x86/include/asm/pgtable-3level.h +++ b/arch/x86/include/asm/pgtable-3level.h @@ -98,6 +98,9 @@ static inline void native_set_pmd(pmd_t *pmdp, pmd_t pmd) static inline void native_set_pud(pud_t *pudp, pud_t pud) { +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pud.p4d.pgd = pti_set_user_pgtbl(&pudp->p4d.pgd, pud.p4d.pgd); +#endif set_64bit((unsigned long long *)(pudp), native_pud_val(pud)); } @@ -229,6 +232,10 @@ static inline pud_t native_pudp_get_and_clear(pud_t *pudp) { union split_pud res, *orig = (union split_pud *)pudp; +#ifdef CONFIG_PAGE_TABLE_ISOLATION + pti_set_user_pgtbl(&pudp->p4d.pgd, __pgd(0)); +#endif + /* xchg acts as a barrier before setting of the high bits */ res.pud_low = xchg(&orig->pud_low, 0); res.pud_high = orig->pud_high; diff --git a/arch/x86/include/asm/pgtable-3level_types.h b/arch/x86/include/asm/pgtable-3level_types.h index 6a59a6d0cc50..858358a82b14 100644 --- a/arch/x86/include/asm/pgtable-3level_types.h +++ b/arch/x86/include/asm/pgtable-3level_types.h @@ -21,9 +21,10 @@ typedef union { #endif /* !__ASSEMBLY__ */ #ifdef CONFIG_PARAVIRT -#define SHARED_KERNEL_PMD (pv_info.shared_kernel_pmd) +#define SHARED_KERNEL_PMD ((!static_cpu_has(X86_FEATURE_PTI) && \ + (pv_info.shared_kernel_pmd))) #else -#define SHARED_KERNEL_PMD 1 +#define SHARED_KERNEL_PMD (!static_cpu_has(X86_FEATURE_PTI)) #endif /* @@ -45,5 +46,6 @@ typedef union { #define PTRS_PER_PTE 512 #define MAX_POSSIBLE_PHYSMEM_BITS 36 +#define PGD_KERNEL_START (CONFIG_PAGE_OFFSET >> PGDIR_SHIFT) #endif /* _ASM_X86_PGTABLE_3LEVEL_DEFS_H */ diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h index 5715647fc4fe..e39088cb59ab 100644 --- a/arch/x86/include/asm/pgtable.h +++ b/arch/x86/include/asm/pgtable.h @@ -640,8 +640,31 @@ static inline int is_new_memtype_allowed(u64 paddr, unsigned long size, pmd_t *populate_extra_pmd(unsigned long vaddr); pte_t *populate_extra_pte(unsigned long vaddr); + +#ifdef CONFIG_PAGE_TABLE_ISOLATION +pgd_t __pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd); + +/* + * Take a PGD location (pgdp) and a pgd value that needs to be set there. + * Populates the user and returns the resulting PGD that must be set in + * the kernel copy of the page tables. + */ +static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) +{ + if (!static_cpu_has(X86_FEATURE_PTI)) + return pgd; + return __pti_set_user_pgtbl(pgdp, pgd); +} +#else /* CONFIG_PAGE_TABLE_ISOLATION */ +static inline pgd_t pti_set_user_pgtbl(pgd_t *pgdp, pgd_t pgd) +{ + return pgd; +} +#endif /* CONFIG_PAGE_TABLE_ISOLATION */ + #endif /* __ASSEMBLY__ */ + #ifdef CONFIG_X86_32 # include <asm/pgtable_32.h> #else @@ -1154,6 +1177,70 @@ static inline pmd_t pmdp_establish(struct vm_area_struct *vma, } } #endif +/* + * Page table pages are page-aligned. The lower half of the top + * level is used for userspace and the top half for the kernel. + * + * Returns true for parts of the PGD that map userspace and + * false for the parts that map the kernel. + */ +static inline bool pgdp_maps_userspace(void *__ptr) +{ + unsigned long ptr = (unsigned long)__ptr; + + return (((ptr & ~PAGE_MASK) / sizeof(pgd_t)) < PGD_KERNEL_START); +} + +static inline int pgd_large(pgd_t pgd) { return 0; } + +#ifdef CONFIG_PAGE_TABLE_ISOLATION +/* + * All top-level PAGE_TABLE_ISOLATION page tables are order-1 pages + * (8k-aligned and 8k in size). The kernel one is at the beginning 4k and + * the user one is in the last 4k. To switch between them, you + * just need to flip the 12th bit in their addresses. + */ +#define PTI_PGTABLE_SWITCH_BIT PAGE_SHIFT + +/* + * This generates better code than the inline assembly in + * __set_bit(). + */ +static inline void *ptr_set_bit(void *ptr, int bit) +{ + unsigned long __ptr = (unsigned long)ptr; + + __ptr |= BIT(bit); + return (void *)__ptr; +} +static inline void *ptr_clear_bit(void *ptr, int bit) +{ + unsigned long __ptr = (unsigned long)ptr; + + __ptr &= ~BIT(bit); + return (void *)__ptr; +} + +static inline pgd_t *kernel_to_user_pgdp(pgd_t *pgdp) +{ + return ptr_set_bit(pgdp, PTI_PGTABLE_SWITCH_BIT); +} + +static inline pgd_t *user_to_kernel_pgdp(pgd_t *pgdp) +{ + return ptr_clear_bit(pgdp, PTI_PGTABLE_SWITCH_BIT); +} + +static inline p4d_t *kernel_to_user_p4dp(p4d_t *p4dp) +{ + return ptr_set_bit(p4dp, PTI_PGTABLE_SWITCH_BIT); +} + +static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp) +{ + return ptr_clear_bit(p4dp, PTI_PGTABLE_SWITCH_BIT); +} +#endif /* CONFIG_PAGE_TABLE_ISOLATION */ /* * clone_pgd_range(pgd_t *dst, pgd_t *src, int count); diff --git a/arch/x86/include/asm/pgtable_32.h b/arch/x86/include/asm/pgtable_32.h index 88a056b01db4..b3ec519e3982 100644 --- a/arch/x86/include/asm/pgtable_32.h +++ b/arch/x86/include/asm/pgtable_32.h @@ -34,8 +34,6 @@ static inline void check_pgt_cache(void) { } void paging_init(void); void sync_initial_page_table(void); -static inline int pgd_large(pgd_t pgd) { return 0; } - /* * Define this if things work differently on an i386 and an i486: * it will (on an i486) warn about kernel memory accesses that are diff --git a/arch/x86/include/asm/pgtable_32_types.h b/arch/x86/include/asm/pgtable_32_types.h index d9a001a4a872..b0bc0fff5f1f 100644 --- a/arch/x86/include/asm/pgtable_32_types.h +++ b/arch/x86/include/asm/pgtable_32_types.h @@ -50,13 +50,18 @@ extern bool __vmalloc_start_set; /* set once high_memory is set */ ((FIXADDR_TOT_START - PAGE_SIZE * (CPU_ENTRY_AREA_PAGES + 1)) \ & PMD_MASK) -#define PKMAP_BASE \ +#define LDT_BASE_ADDR \ ((CPU_ENTRY_AREA_BASE - PAGE_SIZE) & PMD_MASK) +#define LDT_END_ADDR (LDT_BASE_ADDR + PMD_SIZE) + +#define PKMAP_BASE \ + ((LDT_BASE_ADDR - PAGE_SIZE) & PMD_MASK) + #ifdef CONFIG_HIGHMEM # define VMALLOC_END (PKMAP_BASE - 2 * PAGE_SIZE) #else -# define VMALLOC_END (CPU_ENTRY_AREA_BASE - 2 * PAGE_SIZE) +# define VMALLOC_END (LDT_BASE_ADDR - 2 * PAGE_SIZE) #endif #define MODULES_VADDR VMALLOC_START diff --git a/arch/x86/include/asm/pgtable_64.h b/arch/x86/include/asm/pgtable_64.h index 3c5385f9a88f..acb6970e7bcf 100644 --- a/arch/x86/include/asm/pgtable_64.h +++ b/arch/x86/include/asm/pgtable_64.h @@ -132,90 +132,6 @@ static inline pud_t native_pudp_get_and_clear(pud_t *xp) #endif } -#ifdef CONFIG_PAGE_TABLE_ISOLATION -/* - * All top-level PAGE_TABLE_ISOLATION page tables are order-1 pages - * (8k-aligned and 8k in size). The kernel one is at the beginning 4k and - * the user one is in the last 4k. To switch between them, you - * just need to flip the 12th bit in their addresses. - */ -#define PTI_PGTABLE_SWITCH_BIT PAGE_SHIFT - -/* - * This generates better code than the inline assembly in - * __set_bit(). - */ -static inline void *ptr_set_bit(void *ptr, int bit) -{ - unsigned long __ptr = (unsigned long)ptr; - - __ptr |= BIT(bit); - return (void *)__ptr; -} -static inline void *ptr_clear_bit(void *ptr, int bit) -{ - unsigned long __ptr = (unsigned long)ptr; - - __ptr &= ~BIT(bit); - return (void *)__ptr; -} - -static inline pgd_t *kernel_to_user_pgdp(pgd_t *pgdp) -{ - return ptr_set_bit(pgdp, PTI_PGTABLE_SWITCH_BIT); -} - -static inline pgd_t *user_to_kernel_pgdp(pgd_t *pgdp) -{ - return ptr_clear_bit(pgdp, PTI_PGTABLE_SWITCH_BIT); -} - -static inline p4d_t *kernel_to_user_p4dp(p4d_t *p4dp) -{ - return ptr_set_bit(p4dp, PTI_PGTABLE_SWITCH_BIT); -} - -static inline p4d_t *user_to_kernel_p4dp(p4d_t *p4dp) -{ - return ptr_clear_bit(p4dp, PTI_PGTABLE_SWITCH_BIT); -} -#endif /* CONFIG_PAGE_TABLE_ISOLATION */ - -/* - * Page table pages are page-aligned. The lower half of the top - * level is used for userspace and the top half for the kernel. - * - * Returns true for parts of the PGD that map userspace and - * false for the parts that map the kernel. - */ -static inline bool pgdp_maps_userspace(void *__ptr) -{ - unsigned long ptr = (unsigned long)__ptr; - - return (ptr & ~PAGE_MASK) < (PAGE_SIZE / 2); -} - -#ifdef CONFIG_PAGE_TABLE_ISOLATION -pgd_t __pti_set_user_pgd(pgd_t *pgdp, pgd_t pgd); - -/* - * Take a PGD location (pgdp) and a pgd value that needs to be set there. - * Populates the user and returns the resulting PGD that must be set in - * the kernel copy of the page tables. - */ -static inline pgd_t pti_set_user_pgd(pgd_t *pgdp, pgd_t pgd) -{ - if (!static_cpu_has(X86_FEATURE_PTI)) - return pgd; - return __pti_set_user_pgd(pgdp, pgd); -} -#else -static inline pgd_t pti_set_user_pgd(pgd_t *pgdp, pgd_t pgd) -{ - return pgd; -} -#endif - static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d) { pgd_t pgd; @@ -226,7 +142,7 @@ static inline void native_set_p4d(p4d_t *p4dp, p4d_t p4d) } pgd = native_make_pgd(native_p4d_val(p4d)); - pgd = pti_set_user_pgd((pgd_t *)p4dp, pgd); + pgd = pti_set_user_pgtbl((pgd_t *)p4dp, pgd); *p4dp = native_make_p4d(native_pgd_val(pgd)); } @@ -237,7 +153,7 @@ static inline void native_p4d_clear(p4d_t *p4d) static inline void native_set_pgd(pgd_t *pgdp, pgd_t pgd) { - *pgdp = pti_set_user_pgd(pgdp, pgd); + *pgdp = pti_set_user_pgtbl(pgdp, pgd); } static inline void native_pgd_clear(pgd_t *pgd) @@ -255,7 +171,6 @@ extern void sync_global_pgds(unsigned long start, unsigned long end); /* * Level 4 access. */ -static inline int pgd_large(pgd_t pgd) { return 0; } #define mk_kernel_pgd(address) __pgd((address) | _KERNPG_TABLE) /* PUD - Level3 access */ diff --git a/arch/x86/include/asm/pgtable_64_types.h b/arch/x86/include/asm/pgtable_64_types.h index 054765ab2da2..04edd2d58211 100644 --- a/arch/x86/include/asm/pgtable_64_types.h +++ b/arch/x86/include/asm/pgtable_64_types.h @@ -115,6 +115,7 @@ extern unsigned int ptrs_per_p4d; #define LDT_PGD_ENTRY_L5 -112UL #define LDT_PGD_ENTRY (pgtable_l5_enabled() ? LDT_PGD_ENTRY_L5 : LDT_PGD_ENTRY_L4) #define LDT_BASE_ADDR (LDT_PGD_ENTRY << PGDIR_SHIFT) +#define LDT_END_ADDR (LDT_BASE_ADDR + PGDIR_SIZE) #define __VMALLOC_BASE_L4 0xffffc90000000000UL #define __VMALLOC_BASE_L5 0xffa0000000000000UL @@ -153,4 +154,6 @@ extern unsigned int ptrs_per_p4d; #define EARLY_DYNAMIC_PAGE_TABLES 64 +#define PGD_KERNEL_START ((PAGE_SIZE / 2) / sizeof(pgd_t)) + #endif /* _ASM_X86_PGTABLE_64_DEFS_H */ diff --git a/arch/x86/include/asm/pgtable_types.h b/arch/x86/include/asm/pgtable_types.h index 99fff853c944..b64acb08a62b 100644 --- a/arch/x86/include/asm/pgtable_types.h +++ b/arch/x86/include/asm/pgtable_types.h @@ -50,6 +50,7 @@ #define _PAGE_GLOBAL (_AT(pteval_t, 1) << _PAGE_BIT_GLOBAL) #define _PAGE_SOFTW1 (_AT(pteval_t, 1) << _PAGE_BIT_SOFTW1) #define _PAGE_SOFTW2 (_AT(pteval_t, 1) << _PAGE_BIT_SOFTW2) +#define _PAGE_SOFTW3 (_AT(pteval_t, 1) << _PAGE_BIT_SOFTW3) #define _PAGE_PAT (_AT(pteval_t, 1) << _PAGE_BIT_PAT) #define _PAGE_PAT_LARGE (_AT(pteval_t, 1) << _PAGE_BIT_PAT_LARGE) #define _PAGE_SPECIAL (_AT(pteval_t, 1) << _PAGE_BIT_SPECIAL) @@ -266,14 +267,37 @@ typedef struct pgprot { pgprotval_t pgprot; } pgprot_t; typedef struct { pgdval_t pgd; } pgd_t; +#ifdef CONFIG_X86_PAE + +/* + * PHYSICAL_PAGE_MASK might be non-constant when SME is compiled in, so we can't + * use it here. + */ + +#define PGD_PAE_PAGE_MASK ((signed long)PAGE_MASK) +#define PGD_PAE_PHYS_MASK (((1ULL << __PHYSICAL_MASK_SHIFT)-1) & PGD_PAE_PAGE_MASK) + +/* + * PAE allows Base Address, P, PWT, PCD and AVL bits to be set in PGD entries. + * All other bits are Reserved MBZ + */ +#define PGD_ALLOWED_BITS (PGD_PAE_PHYS_MASK | _PAGE_PRESENT | \ + _PAGE_PWT | _PAGE_PCD | \ + _PAGE_SOFTW1 | _PAGE_SOFTW2 | _PAGE_SOFTW3) + +#else +/* No need to mask any bits for !PAE */ +#define PGD_ALLOWED_BITS (~0ULL) +#endif + static inline pgd_t native_make_pgd(pgdval_t val) { - return (pgd_t) { val }; + return (pgd_t) { val & PGD_ALLOWED_BITS }; } static inline pgdval_t native_pgd_val(pgd_t pgd) { - return pgd.pgd; + return pgd.pgd & PGD_ALLOWED_BITS; } static inline pgdval_t pgd_flags(pgd_t pgd) diff --git a/arch/x86/include/asm/processor-flags.h b/arch/x86/include/asm/processor-flags.h index 625a52a5594f..02c2cbda4a74 100644 --- a/arch/x86/include/asm/processor-flags.h +++ b/arch/x86/include/asm/processor-flags.h @@ -39,10 +39,6 @@ #define CR3_PCID_MASK 0xFFFull #define CR3_NOFLUSH BIT_ULL(63) -#ifdef CONFIG_PAGE_TABLE_ISOLATION -# define X86_CR3_PTI_PCID_USER_BIT 11 -#endif - #else /* * CR3_ADDR_MASK needs at least bits 31:5 set on PAE systems, and we save @@ -53,4 +49,8 @@ #define CR3_NOFLUSH 0 #endif +#ifdef CONFIG_PAGE_TABLE_ISOLATION +# define X86_CR3_PTI_PCID_USER_BIT 11 +#endif + #endif /* _ASM_X86_PROCESSOR_FLAGS_H */ diff --git a/arch/x86/include/asm/pti.h b/arch/x86/include/asm/pti.h index 38a17f1d5c9d..5df09a0b80b8 100644 --- a/arch/x86/include/asm/pti.h +++ b/arch/x86/include/asm/pti.h @@ -6,10 +6,9 @@ #ifdef CONFIG_PAGE_TABLE_ISOLATION extern void pti_init(void); extern void pti_check_boottime_disable(void); -extern void pti_clone_kernel_text(void); +extern void pti_finalize(void); #else static inline void pti_check_boottime_disable(void) { } -static inline void pti_clone_kernel_text(void) { } #endif #endif /* __ASSEMBLY__ */ diff --git a/arch/x86/include/asm/sections.h b/arch/x86/include/asm/sections.h index 5c019d23d06b..4a911a382ade 100644 --- a/arch/x86/include/asm/sections.h +++ b/arch/x86/include/asm/sections.h @@ -7,6 +7,7 @@ extern char __brk_base[], __brk_limit[]; extern struct exception_table_entry __stop___ex_table[]; +extern char __end_rodata_aligned[]; #if defined(CONFIG_X86_64) extern char __end_rodata_hpage_align[]; diff --git a/arch/x86/include/asm/switch_to.h b/arch/x86/include/asm/switch_to.h index eb5f7999a893..36bd243843d6 100644 --- a/arch/x86/include/asm/switch_to.h +++ b/arch/x86/include/asm/switch_to.h @@ -87,15 +87,25 @@ static inline void refresh_sysenter_cs(struct thread_struct *thread) #endif /* This is used when switching tasks or entering/exiting vm86 mode. */ -static inline void update_sp0(struct task_struct *task) +static inline void update_task_stack(struct task_struct *task) { - /* On x86_64, sp0 always points to the entry trampoline stack, which is constant: */ + /* sp0 always points to the entry trampoline stack, which is constant: */ #ifdef CONFIG_X86_32 - load_sp0(task->thread.sp0); + if (static_cpu_has(X86_FEATURE_XENPV)) + load_sp0(task->thread.sp0); + else + this_cpu_write(cpu_tss_rw.x86_tss.sp1, task->thread.sp0); #else + /* + * x86-64 updates x86_tss.sp1 via cpu_current_top_of_stack. That + * doesn't work on x86-32 because sp1 and + * cpu_current_top_of_stack have different values (because of + * the non-zero stack-padding on 32bit). + */ if (static_cpu_has(X86_FEATURE_XENPV)) load_sp0(task_top_of_stack(task)); #endif + } #endif /* _ASM_X86_SWITCH_TO_H */ |