#ifndef _ASM_X86_DESC_H #define _ASM_X86_DESC_H #include <asm/desc_defs.h> #include <asm/ldt.h> #include <asm/mmu.h> #include <linux/smp.h> #include <linux/percpu.h> static inline void fill_ldt(struct desc_struct *desc, const struct user_desc *info) { desc->limit0 = info->limit & 0x0ffff; desc->base0 = (info->base_addr & 0x0000ffff); desc->base1 = (info->base_addr & 0x00ff0000) >> 16; desc->type = (info->read_exec_only ^ 1) << 1; desc->type |= info->contents << 2; desc->s = 1; desc->dpl = 0x3; desc->p = info->seg_not_present ^ 1; desc->limit = (info->limit & 0xf0000) >> 16; desc->avl = info->useable; desc->d = info->seg_32bit; desc->g = info->limit_in_pages; desc->base2 = (info->base_addr & 0xff000000) >> 24; /* * Don't allow setting of the lm bit. It would confuse * user_64bit_mode and would get overridden by sysret anyway. */ desc->l = 0; } extern struct desc_ptr idt_descr; extern gate_desc idt_table[]; extern struct desc_ptr debug_idt_descr; extern gate_desc debug_idt_table[]; struct gdt_page { struct desc_struct gdt[GDT_ENTRIES]; } __attribute__((aligned(PAGE_SIZE))); DECLARE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page); static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu) { return per_cpu(gdt_page, cpu).gdt; } #ifdef CONFIG_X86_64 static inline void pack_gate(gate_desc *gate, unsigned type, unsigned long func, unsigned dpl, unsigned ist, unsigned seg) { gate->offset_low = PTR_LOW(func); gate->segment = __KERNEL_CS; gate->ist = ist; gate->p = 1; gate->dpl = dpl; gate->zero0 = 0; gate->zero1 = 0; gate->type = type; gate->offset_middle = PTR_MIDDLE(func); gate->offset_high = PTR_HIGH(func); } #else static inline void pack_gate(gate_desc *gate, unsigned char type, unsigned long base, unsigned dpl, unsigned flags, unsigned short seg) { gate->a = (seg << 16) | (base & 0xffff); gate->b = (base & 0xffff0000) | (((0x80 | type | (dpl << 5)) & 0xff) << 8); } #endif static inline int desc_empty(const void *ptr) { const u32 *desc = ptr; return !(desc[0] | desc[1]); } #ifdef CONFIG_PARAVIRT #include <asm/paravirt.h> #else #define load_TR_desc() native_load_tr_desc() #define load_gdt(dtr) native_load_gdt(dtr) #define load_idt(dtr) native_load_idt(dtr) #define load_tr(tr) asm volatile("ltr %0"::"m" (tr)) #define load_ldt(ldt) asm volatile("lldt %0"::"m" (ldt)) #define store_gdt(dtr) native_store_gdt(dtr) #define store_idt(dtr) native_store_idt(dtr) #define store_tr(tr) (tr = native_store_tr()) #define load_TLS(t, cpu) native_load_tls(t, cpu) #define set_ldt native_set_ldt #define write_ldt_entry(dt, entry, desc) native_write_ldt_entry(dt, entry, desc) #define write_gdt_entry(dt, entry, desc, type) native_write_gdt_entry(dt, entry, desc, type) #define write_idt_entry(dt, entry, g) native_write_idt_entry(dt, entry, g) static inline void paravirt_alloc_ldt(struct desc_struct *ldt, unsigned entries) { } static inline void paravirt_free_ldt(struct desc_struct *ldt, unsigned entries) { } #endif /* CONFIG_PARAVIRT */ #define store_ldt(ldt) asm("sldt %0" : "=m"(ldt)) static inline void native_write_idt_entry(gate_desc *idt, int entry, const gate_desc *gate) { memcpy(&idt[entry], gate, sizeof(*gate)); } static inline void native_write_ldt_entry(struct desc_struct *ldt, int entry, const void *desc) { memcpy(&ldt[entry], desc, 8); } static inline void native_write_gdt_entry(struct desc_struct *gdt, int entry, const void *desc, int type) { unsigned int size; switch (type) { case DESC_TSS: size = sizeof(tss_desc); break; case DESC_LDT: size = sizeof(ldt_desc); break; default: size = sizeof(*gdt); break; } memcpy(&gdt[entry], desc, size); } static inline void pack_descriptor(struct desc_struct *desc, unsigned long base, unsigned long limit, unsigned char type, unsigned char flags) { desc->a = ((base & 0xffff) << 16) | (limit & 0xffff); desc->b = (base & 0xff000000) | ((base & 0xff0000) >> 16) | (limit & 0x000f0000) | ((type & 0xff) << 8) | ((flags & 0xf) << 20); desc->p = 1; } static inline void set_tssldt_descriptor(void *d, unsigned long addr, unsigned type, unsigned size) { #ifdef CONFIG_X86_64 struct ldttss_desc64 *desc = d; memset(desc, 0, sizeof(*desc)); desc->limit0 = size & 0xFFFF; desc->base0 = PTR_LOW(addr); desc->base1 = PTR_MIDDLE(addr) & 0xFF; desc->type = type; desc->p = 1; desc->limit1 = (size >> 16) & 0xF; desc->base2 = (PTR_MIDDLE(addr) >> 8) & 0xFF; desc->base3 = PTR_HIGH(addr); #else pack_descriptor((struct desc_struct *)d, addr, size, 0x80 | type, 0); #endif } static inline void __set_tss_desc(unsigned cpu, unsigned int entry, void *addr) { struct desc_struct *d = get_cpu_gdt_table(cpu); tss_desc tss; /* * sizeof(unsigned long) coming from an extra "long" at the end * of the iobitmap. See tss_struct definition in processor.h * * -1? seg base+limit should be pointing to the address of the * last valid byte */ set_tssldt_descriptor(&tss, (unsigned long)addr, DESC_TSS, IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1); write_gdt_entry(d, entry, &tss, DESC_TSS); } #define set_tss_desc(cpu, addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr) static inline void native_set_ldt(const void *addr, unsigned int entries) { if (likely(entries == 0)) asm volatile("lldt %w0"::"q" (0)); else { unsigned cpu = smp_processor_id(); ldt_desc ldt; set_tssldt_descriptor(&ldt, (unsigned long)addr, DESC_LDT, entries * LDT_ENTRY_SIZE - 1); write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, &ldt, DESC_LDT); asm volatile("lldt %w0"::"q" (GDT_ENTRY_LDT*8)); } } static inline void native_load_tr_desc(void) { asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8)); } static inline void native_load_gdt(const struct desc_ptr *dtr) { asm volatile("lgdt %0"::"m" (*dtr)); } static inline void native_load_idt(const struct desc_ptr *dtr) { asm volatile("lidt %0"::"m" (*dtr)); } static inline void native_store_gdt(struct desc_ptr *dtr) { asm volatile("sgdt %0":"=m" (*dtr)); } static inline void native_store_idt(struct desc_ptr *dtr) { asm volatile("sidt %0":"=m" (*dtr)); } static inline unsigned long native_store_tr(void) { unsigned long tr; asm volatile("str %0":"=r" (tr)); return tr; } static inline void native_load_tls(struct thread_struct *t, unsigned int cpu) { struct desc_struct *gdt = get_cpu_gdt_table(cpu); unsigned int i; for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++) gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]; } /* This intentionally ignores lm, since 32-bit apps don't have that field. */ #define LDT_empty(info) \ ((info)->base_addr == 0 && \ (info)->limit == 0 && \ (info)->contents == 0 && \ (info)->read_exec_only == 1 && \ (info)->seg_32bit == 0 && \ (info)->limit_in_pages == 0 && \ (info)->seg_not_present == 1 && \ (info)->useable == 0) /* Lots of programs expect an all-zero user_desc to mean "no segment at all". */ static inline bool LDT_zero(const struct user_desc *info) { return (info->base_addr == 0 && info->limit == 0 && info->contents == 0 && info->read_exec_only == 0 && info->seg_32bit == 0 && info->limit_in_pages == 0 && info->seg_not_present == 0 && info->useable == 0); } static inline void clear_LDT(void) { set_ldt(NULL, 0); } static inline unsigned long get_desc_base(const struct desc_struct *desc) { return (unsigned)(desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24)); } static inline void set_desc_base(struct desc_struct *desc, unsigned long base) { desc->base0 = base & 0xffff; desc->base1 = (base >> 16) & 0xff; desc->base2 = (base >> 24) & 0xff; } static inline unsigned long get_desc_limit(const struct desc_struct *desc) { return desc->limit0 | (desc->limit << 16); } static inline void set_desc_limit(struct desc_struct *desc, unsigned long limit) { desc->limit0 = limit & 0xffff; desc->limit = (limit >> 16) & 0xf; } #ifdef CONFIG_X86_64 static inline void set_nmi_gate(int gate, void *addr) { gate_desc s; pack_gate(&s, GATE_INTERRUPT, (unsigned long)addr, 0, 0, __KERNEL_CS); write_idt_entry(debug_idt_table, gate, &s); } #endif #ifdef CONFIG_TRACING extern struct desc_ptr trace_idt_descr; extern gate_desc trace_idt_table[]; static inline void write_trace_idt_entry(int entry, const gate_desc *gate) { write_idt_entry(trace_idt_table, entry, gate); } static inline void _trace_set_gate(int gate, unsigned type, void *addr, unsigned dpl, unsigned ist, unsigned seg) { gate_desc s; pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg); /* * does not need to be atomic because it is only done once at * setup time */ write_trace_idt_entry(gate, &s); } #else static inline void write_trace_idt_entry(int entry, const gate_desc *gate) { } #define _trace_set_gate(gate, type, addr, dpl, ist, seg) #endif static inline void _set_gate(int gate, unsigned type, void *addr, unsigned dpl, unsigned ist, unsigned seg) { gate_desc s; pack_gate(&s, type, (unsigned long)addr, dpl, ist, seg); /* * does not need to be atomic because it is only done once at * setup time */ write_idt_entry(idt_table, gate, &s); write_trace_idt_entry(gate, &s); } /* * This needs to use 'idt_table' rather than 'idt', and * thus use the _nonmapped_ version of the IDT, as the * Pentium F0 0F bugfix can have resulted in the mapped * IDT being write-protected. */ #define set_intr_gate_notrace(n, addr) \ do { \ BUG_ON((unsigned)n > 0xFF); \ _set_gate(n, GATE_INTERRUPT, (void *)addr, 0, 0, \ __KERNEL_CS); \ } while (0) #define set_intr_gate(n, addr) \ do { \ set_intr_gate_notrace(n, addr); \ _trace_set_gate(n, GATE_INTERRUPT, (void *)trace_##addr,\ 0, 0, __KERNEL_CS); \ } while (0) extern int first_system_vector; /* used_vectors is BITMAP for irq is not managed by percpu vector_irq */ extern unsigned long used_vectors[]; static inline void alloc_system_vector(int vector) { if (!test_bit(vector, used_vectors)) { set_bit(vector, used_vectors); if (first_system_vector > vector) first_system_vector = vector; } else { BUG(); } } #define alloc_intr_gate(n, addr) \ do { \ alloc_system_vector(n); \ set_intr_gate(n, addr); \ } while (0) /* * This routine sets up an interrupt gate at directory privilege level 3. */ static inline void set_system_intr_gate(unsigned int n, void *addr) { BUG_ON((unsigned)n > 0xFF); _set_gate(n, GATE_INTERRUPT, addr, 0x3, 0, __KERNEL_CS); } static inline void set_system_trap_gate(unsigned int n, void *addr) { BUG_ON((unsigned)n > 0xFF); _set_gate(n, GATE_TRAP, addr, 0x3, 0, __KERNEL_CS); } static inline void set_trap_gate(unsigned int n, void *addr) { BUG_ON((unsigned)n > 0xFF); _set_gate(n, GATE_TRAP, addr, 0, 0, __KERNEL_CS); } static inline void set_task_gate(unsigned int n, unsigned int gdt_entry) { BUG_ON((unsigned)n > 0xFF); _set_gate(n, GATE_TASK, (void *)0, 0, 0, (gdt_entry<<3)); } static inline void set_intr_gate_ist(int n, void *addr, unsigned ist) { BUG_ON((unsigned)n > 0xFF); _set_gate(n, GATE_INTERRUPT, addr, 0, ist, __KERNEL_CS); } static inline void set_system_intr_gate_ist(int n, void *addr, unsigned ist) { BUG_ON((unsigned)n > 0xFF); _set_gate(n, GATE_INTERRUPT, addr, 0x3, ist, __KERNEL_CS); } #ifdef CONFIG_X86_64 DECLARE_PER_CPU(u32, debug_idt_ctr); static inline bool is_debug_idt_enabled(void) { if (this_cpu_read(debug_idt_ctr)) return true; return false; } static inline void load_debug_idt(void) { load_idt((const struct desc_ptr *)&debug_idt_descr); } #else static inline bool is_debug_idt_enabled(void) { return false; } static inline void load_debug_idt(void) { } #endif #ifdef CONFIG_TRACING extern atomic_t trace_idt_ctr; static inline bool is_trace_idt_enabled(void) { if (atomic_read(&trace_idt_ctr)) return true; return false; } static inline void load_trace_idt(void) { load_idt((const struct desc_ptr *)&trace_idt_descr); } #else static inline bool is_trace_idt_enabled(void) { return false; } static inline void load_trace_idt(void) { } #endif /* * The load_current_idt() must be called with interrupts disabled * to avoid races. That way the IDT will always be set back to the expected * descriptor. It's also called when a CPU is being initialized, and * that doesn't need to disable interrupts, as nothing should be * bothering the CPU then. */ static inline void load_current_idt(void) { if (is_debug_idt_enabled()) load_debug_idt(); else if (is_trace_idt_enabled()) load_trace_idt(); else load_idt((const struct desc_ptr *)&idt_descr); } #endif /* _ASM_X86_DESC_H */