diff options
Diffstat (limited to 'arch/x86/kernel/cpu/common.c')
| -rw-r--r-- | arch/x86/kernel/cpu/common.c | 100 |
1 files changed, 3 insertions, 97 deletions
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 7416da3ec4df..c9757f07d738 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -506,102 +506,8 @@ static const unsigned int exception_stack_sizes[N_EXCEPTION_STACKS] = { [0 ... N_EXCEPTION_STACKS - 1] = EXCEPTION_STKSZ, [DEBUG_STACK - 1] = DEBUG_STKSZ }; - -static DEFINE_PER_CPU_PAGE_ALIGNED(char, exception_stacks - [(N_EXCEPTION_STACKS - 1) * EXCEPTION_STKSZ + DEBUG_STKSZ]); -#endif - -static DEFINE_PER_CPU_PAGE_ALIGNED(struct SYSENTER_stack_page, - SYSENTER_stack_storage); - -static void __init -set_percpu_fixmap_pages(int idx, void *ptr, int pages, pgprot_t prot) -{ - for ( ; pages; pages--, idx--, ptr += PAGE_SIZE) - __set_fixmap(idx, per_cpu_ptr_to_phys(ptr), prot); -} - -/* Setup the fixmap mappings only once per-processor */ -static void __init setup_cpu_entry_area(int cpu) -{ -#ifdef CONFIG_X86_64 - extern char _entry_trampoline[]; - - /* On 64-bit systems, we use a read-only fixmap GDT and TSS. */ - pgprot_t gdt_prot = PAGE_KERNEL_RO; - pgprot_t tss_prot = PAGE_KERNEL_RO; -#else - /* - * On native 32-bit systems, the GDT cannot be read-only because - * our double fault handler uses a task gate, and entering through - * a task gate needs to change an available TSS to busy. If the - * GDT is read-only, that will triple fault. The TSS cannot be - * read-only because the CPU writes to it on task switches. - * - * On Xen PV, the GDT must be read-only because the hypervisor - * requires it. - */ - pgprot_t gdt_prot = boot_cpu_has(X86_FEATURE_XENPV) ? - PAGE_KERNEL_RO : PAGE_KERNEL; - pgprot_t tss_prot = PAGE_KERNEL; -#endif - - __set_fixmap(get_cpu_entry_area_index(cpu, gdt), get_cpu_gdt_paddr(cpu), gdt_prot); - set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, SYSENTER_stack_page), - per_cpu_ptr(&SYSENTER_stack_storage, cpu), 1, - PAGE_KERNEL); - - /* - * The Intel SDM says (Volume 3, 7.2.1): - * - * Avoid placing a page boundary in the part of the TSS that the - * processor reads during a task switch (the first 104 bytes). The - * processor may not correctly perform address translations if a - * boundary occurs in this area. During a task switch, the processor - * reads and writes into the first 104 bytes of each TSS (using - * contiguous physical addresses beginning with the physical address - * of the first byte of the TSS). So, after TSS access begins, if - * part of the 104 bytes is not physically contiguous, the processor - * will access incorrect information without generating a page-fault - * exception. - * - * There are also a lot of errata involving the TSS spanning a page - * boundary. Assert that we're not doing that. - */ - BUILD_BUG_ON((offsetof(struct tss_struct, x86_tss) ^ - offsetofend(struct tss_struct, x86_tss)) & PAGE_MASK); - BUILD_BUG_ON(sizeof(struct tss_struct) % PAGE_SIZE != 0); - set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, tss), - &per_cpu(cpu_tss_rw, cpu), - sizeof(struct tss_struct) / PAGE_SIZE, - tss_prot); - -#ifdef CONFIG_X86_32 - per_cpu(cpu_entry_area, cpu) = get_cpu_entry_area(cpu); #endif -#ifdef CONFIG_X86_64 - BUILD_BUG_ON(sizeof(exception_stacks) % PAGE_SIZE != 0); - BUILD_BUG_ON(sizeof(exception_stacks) != - sizeof(((struct cpu_entry_area *)0)->exception_stacks)); - set_percpu_fixmap_pages(get_cpu_entry_area_index(cpu, exception_stacks), - &per_cpu(exception_stacks, cpu), - sizeof(exception_stacks) / PAGE_SIZE, - PAGE_KERNEL); - - __set_fixmap(get_cpu_entry_area_index(cpu, entry_trampoline), - __pa_symbol(_entry_trampoline), PAGE_KERNEL_RX); -#endif -} - -void __init setup_cpu_entry_areas(void) -{ - unsigned int cpu; - - for_each_possible_cpu(cpu) - setup_cpu_entry_area(cpu); -} - /* Load the original GDT from the per-cpu structure */ void load_direct_gdt(int cpu) { @@ -1348,7 +1254,7 @@ void enable_sep_cpu(void) tss->x86_tss.ss1 = __KERNEL_CS; wrmsr(MSR_IA32_SYSENTER_CS, tss->x86_tss.ss1, 0); - wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1), 0); + wrmsr(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1), 0); wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long)entry_SYSENTER_32, 0); put_cpu(); @@ -1465,7 +1371,7 @@ void syscall_init(void) * AMD doesn't allow SYSENTER in long mode (either 32- or 64-bit). */ wrmsrl_safe(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS); - wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_SYSENTER_stack(cpu) + 1)); + wrmsrl_safe(MSR_IA32_SYSENTER_ESP, (unsigned long)(cpu_entry_stack(cpu) + 1)); wrmsrl_safe(MSR_IA32_SYSENTER_EIP, (u64)entry_SYSENTER_compat); #else wrmsrl(MSR_CSTAR, (unsigned long)ignore_sysret); @@ -1680,7 +1586,7 @@ void cpu_init(void) */ set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss); load_TR_desc(); - load_sp0((unsigned long)(cpu_SYSENTER_stack(cpu) + 1)); + load_sp0((unsigned long)(cpu_entry_stack(cpu) + 1)); load_mm_ldt(&init_mm); |