diff options
Diffstat (limited to 'arch/x86/include/asm/desc.h')
| -rw-r--r-- | arch/x86/include/asm/desc.h | 409 |
1 files changed, 409 insertions, 0 deletions
diff --git a/arch/x86/include/asm/desc.h b/arch/x86/include/asm/desc.h new file mode 100644 index 00000000000..e6b82b17b07 --- /dev/null +++ b/arch/x86/include/asm/desc.h @@ -0,0 +1,409 @@ +#ifndef _ASM_X86_DESC_H +#define _ASM_X86_DESC_H + +#ifndef __ASSEMBLY__ +#include <asm/desc_defs.h> +#include <asm/ldt.h> +#include <asm/mmu.h> +#include <linux/smp.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 is useless anyway + * because 64bit system calls require __USER_CS: + */ + desc->l = 0; +} + +extern struct desc_ptr idt_descr; +extern gate_desc idt_table[]; + +struct gdt_page { + struct desc_struct gdt[GDT_ENTRIES]; +} __attribute__((aligned(PAGE_SIZE))); +DECLARE_PER_CPU(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 store_ldt(ldt) asm("sldt %0":"=m" (ldt)) + +#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 */ + +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(struct desc_struct); + 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) +{ + unsigned int i; + struct desc_struct *gdt = get_cpu_gdt_table(cpu); + + for (i = 0; i < GDT_ENTRY_TLS_ENTRIES; i++) + gdt[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]; +} + +#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) + +#ifdef CONFIG_X86_64 +#define LDT_empty(info) (_LDT_empty(info) && ((info)->lm == 0)) +#else +#define LDT_empty(info) (_LDT_empty(info)) +#endif + +static inline void clear_LDT(void) +{ + set_ldt(NULL, 0); +} + +/* + * load one particular LDT into the current CPU + */ +static inline void load_LDT_nolock(mm_context_t *pc) +{ + set_ldt(pc->ldt, pc->size); +} + +static inline void load_LDT(mm_context_t *pc) +{ + preempt_disable(); + load_LDT_nolock(pc); + preempt_enable(); +} + +static inline unsigned long get_desc_base(const struct desc_struct *desc) +{ + return desc->base0 | ((desc->base1) << 16) | ((desc->base2) << 24); +} + +static inline unsigned long get_desc_limit(const struct desc_struct *desc) +{ + return desc->limit0 | (desc->limit << 16); +} + +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); +} + +/* + * 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. + */ +static inline void set_intr_gate(unsigned int n, void *addr) +{ + BUG_ON((unsigned)n > 0xFF); + _set_gate(n, GATE_INTERRUPT, addr, 0, 0, __KERNEL_CS); +} + +#define SYS_VECTOR_FREE 0 +#define SYS_VECTOR_ALLOCED 1 + +extern int first_system_vector; +extern char system_vectors[]; + +static inline void alloc_system_vector(int vector) +{ + if (system_vectors[vector] == SYS_VECTOR_FREE) { + system_vectors[vector] = SYS_VECTOR_ALLOCED; + if (first_system_vector > vector) + first_system_vector = vector; + } else + BUG(); +} + +static inline void alloc_intr_gate(unsigned int n, void *addr) +{ + alloc_system_vector(n); + set_intr_gate(n, addr); +} + +/* + * 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); +} + +#else +/* + * GET_DESC_BASE reads the descriptor base of the specified segment. + * + * Args: + * idx - descriptor index + * gdt - GDT pointer + * base - 32bit register to which the base will be written + * lo_w - lo word of the "base" register + * lo_b - lo byte of the "base" register + * hi_b - hi byte of the low word of the "base" register + * + * Example: + * GET_DESC_BASE(GDT_ENTRY_ESPFIX_SS, %ebx, %eax, %ax, %al, %ah) + * Will read the base address of GDT_ENTRY_ESPFIX_SS and put it into %eax. + */ +#define GET_DESC_BASE(idx, gdt, base, lo_w, lo_b, hi_b) \ + movb idx * 8 + 4(gdt), lo_b; \ + movb idx * 8 + 7(gdt), hi_b; \ + shll $16, base; \ + movw idx * 8 + 2(gdt), lo_w; + + +#endif /* __ASSEMBLY__ */ + +#endif /* _ASM_X86_DESC_H */ |