![Jeremy Fitzhardinge](/assets/img/avatar_default.png)
Fix pack_descriptor: 1. flags are bits 20-23 in the high word 2. limit's 4 msb are bits 16-19 in the high word These haven't mattered so far, because all users have had small limits and a flags setting of 0. Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Andi Kleen <ak@suse.de> ===================================================================
199 lines
5.5 KiB
C
199 lines
5.5 KiB
C
#ifndef __ARCH_DESC_H
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#define __ARCH_DESC_H
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#include <asm/ldt.h>
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#include <asm/segment.h>
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#define CPU_16BIT_STACK_SIZE 1024
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#ifndef __ASSEMBLY__
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#include <linux/preempt.h>
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#include <linux/smp.h>
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#include <linux/percpu.h>
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#include <asm/mmu.h>
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extern struct desc_struct cpu_gdt_table[GDT_ENTRIES];
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DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]);
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struct Xgt_desc_struct {
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unsigned short size;
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unsigned long address __attribute__((packed));
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unsigned short pad;
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} __attribute__ ((packed));
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extern struct Xgt_desc_struct idt_descr;
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DECLARE_PER_CPU(struct Xgt_desc_struct, cpu_gdt_descr);
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static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu)
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{
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return (struct desc_struct *)per_cpu(cpu_gdt_descr, cpu).address;
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}
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/*
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* This is the ldt that every process will get unless we need
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* something other than this.
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*/
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extern struct desc_struct default_ldt[];
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extern struct desc_struct idt_table[];
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extern void set_intr_gate(unsigned int irq, void * addr);
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static inline void pack_descriptor(__u32 *a, __u32 *b,
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unsigned long base, unsigned long limit, unsigned char type, unsigned char flags)
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{
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*a = ((base & 0xffff) << 16) | (limit & 0xffff);
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*b = (base & 0xff000000) | ((base & 0xff0000) >> 16) |
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(limit & 0x000f0000) | ((type & 0xff) << 8) | ((flags & 0xf) << 20);
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}
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static inline void pack_gate(__u32 *a, __u32 *b,
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unsigned long base, unsigned short seg, unsigned char type, unsigned char flags)
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{
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*a = (seg << 16) | (base & 0xffff);
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*b = (base & 0xffff0000) | ((type & 0xff) << 8) | (flags & 0xff);
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}
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#define DESCTYPE_LDT 0x82 /* present, system, DPL-0, LDT */
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#define DESCTYPE_TSS 0x89 /* present, system, DPL-0, 32-bit TSS */
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#define DESCTYPE_TASK 0x85 /* present, system, DPL-0, task gate */
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#define DESCTYPE_INT 0x8e /* present, system, DPL-0, interrupt gate */
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#define DESCTYPE_TRAP 0x8f /* present, system, DPL-0, trap gate */
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#define DESCTYPE_DPL3 0x60 /* DPL-3 */
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#define DESCTYPE_S 0x10 /* !system */
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#define load_TR_desc() __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8))
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#define load_LDT_desc() __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8))
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#define load_gdt(dtr) __asm__ __volatile("lgdt %0"::"m" (*dtr))
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#define load_idt(dtr) __asm__ __volatile("lidt %0"::"m" (*dtr))
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#define load_tr(tr) __asm__ __volatile("ltr %0"::"m" (tr))
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#define load_ldt(ldt) __asm__ __volatile("lldt %0"::"m" (ldt))
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#define store_gdt(dtr) __asm__ ("sgdt %0":"=m" (*dtr))
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#define store_idt(dtr) __asm__ ("sidt %0":"=m" (*dtr))
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#define store_tr(tr) __asm__ ("str %0":"=m" (tr))
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#define store_ldt(ldt) __asm__ ("sldt %0":"=m" (ldt))
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#if TLS_SIZE != 24
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# error update this code.
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#endif
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static inline void load_TLS(struct thread_struct *t, unsigned int cpu)
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{
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#define C(i) get_cpu_gdt_table(cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i]
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C(0); C(1); C(2);
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#undef C
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}
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static inline void write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entry_b)
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{
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__u32 *lp = (__u32 *)((char *)dt + entry*8);
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*lp = entry_a;
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*(lp+1) = entry_b;
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}
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#define write_ldt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
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#define write_gdt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
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#define write_idt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b)
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static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg)
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{
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__u32 a, b;
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pack_gate(&a, &b, (unsigned long)addr, seg, type, 0);
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write_idt_entry(idt_table, gate, a, b);
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}
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static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const void *addr)
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{
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__u32 a, b;
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pack_descriptor(&a, &b, (unsigned long)addr,
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offsetof(struct tss_struct, __cacheline_filler) - 1,
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DESCTYPE_TSS, 0);
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write_gdt_entry(get_cpu_gdt_table(cpu), entry, a, b);
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}
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static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int entries)
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{
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__u32 a, b;
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pack_descriptor(&a, &b, (unsigned long)addr,
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entries * sizeof(struct desc_struct) - 1,
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DESCTYPE_LDT, 0);
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write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, a, b);
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}
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#define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr)
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#define LDT_entry_a(info) \
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((((info)->base_addr & 0x0000ffff) << 16) | ((info)->limit & 0x0ffff))
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#define LDT_entry_b(info) \
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(((info)->base_addr & 0xff000000) | \
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(((info)->base_addr & 0x00ff0000) >> 16) | \
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((info)->limit & 0xf0000) | \
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(((info)->read_exec_only ^ 1) << 9) | \
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((info)->contents << 10) | \
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(((info)->seg_not_present ^ 1) << 15) | \
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((info)->seg_32bit << 22) | \
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((info)->limit_in_pages << 23) | \
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((info)->useable << 20) | \
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0x7000)
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#define LDT_empty(info) (\
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(info)->base_addr == 0 && \
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(info)->limit == 0 && \
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(info)->contents == 0 && \
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(info)->read_exec_only == 1 && \
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(info)->seg_32bit == 0 && \
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(info)->limit_in_pages == 0 && \
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(info)->seg_not_present == 1 && \
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(info)->useable == 0 )
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static inline void clear_LDT(void)
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{
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int cpu = get_cpu();
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set_ldt_desc(cpu, &default_ldt[0], 5);
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load_LDT_desc();
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put_cpu();
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}
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/*
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* load one particular LDT into the current CPU
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*/
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static inline void load_LDT_nolock(mm_context_t *pc, int cpu)
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{
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void *segments = pc->ldt;
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int count = pc->size;
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if (likely(!count)) {
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segments = &default_ldt[0];
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count = 5;
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}
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set_ldt_desc(cpu, segments, count);
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load_LDT_desc();
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}
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static inline void load_LDT(mm_context_t *pc)
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{
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int cpu = get_cpu();
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load_LDT_nolock(pc, cpu);
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put_cpu();
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}
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static inline unsigned long get_desc_base(unsigned long *desc)
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{
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unsigned long base;
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base = ((desc[0] >> 16) & 0x0000ffff) |
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((desc[1] << 16) & 0x00ff0000) |
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(desc[1] & 0xff000000);
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return base;
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}
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#endif /* !__ASSEMBLY__ */
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#endif
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