diff options
Diffstat (limited to 'include/asm-x86/desc.h')
| -rw-r--r-- | include/asm-x86/desc.h | 65 |
1 files changed, 64 insertions, 1 deletions
diff --git a/include/asm-x86/desc.h b/include/asm-x86/desc.h index 47086d2d929..99c4adc851e 100644 --- a/include/asm-x86/desc.h +++ b/include/asm-x86/desc.h @@ -4,6 +4,7 @@ #ifndef __ASSEMBLY__ #include <asm/desc_defs.h> #include <asm/ldt.h> +#include <asm/mmu.h> static inline void fill_ldt(struct desc_struct *desc, struct user_desc *info) { @@ -23,7 +24,8 @@ static inline void fill_ldt(struct desc_struct *desc, struct user_desc *info) desc->base2 = (info->base_addr & 0xff000000) >> 24; } -#endif +extern struct desc_ptr idt_descr; +extern gate_desc idt_table[]; #ifdef CONFIG_X86_32 # include "desc_32.h" @@ -31,4 +33,65 @@ static inline void fill_ldt(struct desc_struct *desc, struct user_desc *info) # include "desc_64.h" #endif +#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(); +} + +#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 |