diff options
Diffstat (limited to 'include/asm-i386/desc.h')
| -rw-r--r-- | include/asm-i386/desc.h | 95 |
1 files changed, 55 insertions, 40 deletions
diff --git a/include/asm-i386/desc.h b/include/asm-i386/desc.h index 5874ef119ffd..f398cc456448 100644 --- a/include/asm-i386/desc.h +++ b/include/asm-i386/desc.h @@ -4,8 +4,6 @@ #include <asm/ldt.h> #include <asm/segment.h> -#define CPU_16BIT_STACK_SIZE 1024 - #ifndef __ASSEMBLY__ #include <linux/preempt.h> @@ -16,8 +14,6 @@ extern struct desc_struct cpu_gdt_table[GDT_ENTRIES]; -DECLARE_PER_CPU(unsigned char, cpu_16bit_stack[CPU_16BIT_STACK_SIZE]); - struct Xgt_desc_struct { unsigned short size; unsigned long address __attribute__((packed)); @@ -33,11 +29,6 @@ static inline struct desc_struct *get_cpu_gdt_table(unsigned int cpu) return (struct desc_struct *)per_cpu(cpu_gdt_descr, cpu).address; } -/* - * This is the ldt that every process will get unless we need - * something other than this. - */ -extern struct desc_struct default_ldt[]; extern struct desc_struct idt_table[]; extern void set_intr_gate(unsigned int irq, void * addr); @@ -64,8 +55,10 @@ static inline void pack_gate(__u32 *a, __u32 *b, #define DESCTYPE_DPL3 0x60 /* DPL-3 */ #define DESCTYPE_S 0x10 /* !system */ +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else #define load_TR_desc() __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8)) -#define load_LDT_desc() __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8)) #define load_gdt(dtr) __asm__ __volatile("lgdt %0"::"m" (*dtr)) #define load_idt(dtr) __asm__ __volatile("lidt %0"::"m" (*dtr)) @@ -88,6 +81,10 @@ static inline void load_TLS(struct thread_struct *t, unsigned int cpu) #undef C } +#define write_ldt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) +#define write_gdt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) +#define write_idt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) + static inline void write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entry_b) { __u32 *lp = (__u32 *)((char *)dt + entry*8); @@ -95,9 +92,25 @@ static inline void write_dt_entry(void *dt, int entry, __u32 entry_a, __u32 entr *(lp+1) = entry_b; } -#define write_ldt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) -#define write_gdt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) -#define write_idt_entry(dt, entry, a, b) write_dt_entry(dt, entry, a, b) +#define set_ldt native_set_ldt +#endif /* CONFIG_PARAVIRT */ + +static inline fastcall 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(); + __u32 a, b; + + pack_descriptor(&a, &b, (unsigned long)addr, + entries * sizeof(struct desc_struct) - 1, + DESCTYPE_LDT, 0); + write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, a, b); + __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8)); + } +} static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg) { @@ -115,14 +128,6 @@ static inline void __set_tss_desc(unsigned int cpu, unsigned int entry, const vo write_gdt_entry(get_cpu_gdt_table(cpu), entry, a, b); } -static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int entries) -{ - __u32 a, b; - pack_descriptor(&a, &b, (unsigned long)addr, - entries * sizeof(struct desc_struct) - 1, - DESCTYPE_LDT, 0); - write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, a, b); -} #define set_tss_desc(cpu,addr) __set_tss_desc(cpu, GDT_ENTRY_TSS, addr) @@ -153,35 +158,22 @@ static inline void set_ldt_desc(unsigned int cpu, void *addr, unsigned int entri static inline void clear_LDT(void) { - int cpu = get_cpu(); - - set_ldt_desc(cpu, &default_ldt[0], 5); - load_LDT_desc(); - put_cpu(); + set_ldt(NULL, 0); } /* * load one particular LDT into the current CPU */ -static inline void load_LDT_nolock(mm_context_t *pc, int cpu) +static inline void load_LDT_nolock(mm_context_t *pc) { - void *segments = pc->ldt; - int count = pc->size; - - if (likely(!count)) { - segments = &default_ldt[0]; - count = 5; - } - - set_ldt_desc(cpu, segments, count); - load_LDT_desc(); + set_ldt(pc->ldt, pc->size); } static inline void load_LDT(mm_context_t *pc) { - int cpu = get_cpu(); - load_LDT_nolock(pc, cpu); - put_cpu(); + preempt_disable(); + load_LDT_nolock(pc); + preempt_enable(); } static inline unsigned long get_desc_base(unsigned long *desc) @@ -193,6 +185,29 @@ static inline unsigned long get_desc_base(unsigned long *desc) return base; } +#else /* __ASSEMBLY__ */ + +/* + * 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 |