LXR linux/arch/x86/um/shared/sysdep/stub

   1/*
   2 * Copyright (C) 2004 Jeff Dike (jdike@addtoit.com)
   3 * Licensed under the GPL
   4 */
   5
   6#ifndef __SYSDEP_STUB_H
   7#define __SYSDEP_STUB_H
   8
   9#include <asm/ptrace.h>
  10#include <generated/asm-offsets.h>
  11
  12#define STUB_MMAP_NR __NR_mmap2
  13#define MMAP_OFFSET(o) ((o) >> UM_KERN_PAGE_SHIFT)
  14
  15static inline long stub_syscall0(long syscall)
  16{
  17        long ret;
  18
  19        __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall));
  20
  21        return ret;
  22}
  23
  24static inline long stub_syscall1(long syscall, long arg1)
  25{
  26        long ret;
  27
  28        __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1));
  29
  30        return ret;
  31}
  32
  33static inline long stub_syscall2(long syscall, long arg1, long arg2)
  34{
  35        long ret;
  36
  37        __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
  38                        "c" (arg2));
  39
  40        return ret;
  41}
  42
  43static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
  44{
  45        long ret;
  46
  47        __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
  48                        "c" (arg2), "d" (arg3));
  49
  50        return ret;
  51}
  52
  53static inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
  54                                 long arg4)
  55{
  56        long ret;
  57
  58        __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
  59                        "c" (arg2), "d" (arg3), "S" (arg4));
  60
  61        return ret;
  62}
  63
  64static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
  65                                 long arg4, long arg5)
  66{
  67        long ret;
  68
  69        __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
  70                        "c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5));
  71
  72        return ret;
  73}
  74
  75static inline void trap_myself(void)
  76{
  77        __asm("int3");
  78}
  79
  80static inline void remap_stack_and_trap(void)
  81{
  82        __asm__ volatile (
  83                "movl %%esp,%%ebx ;"
  84                "andl %0,%%ebx ;"
  85                "movl %1,%%eax ;"
  86                "movl %%ebx,%%edi ; addl %2,%%edi ; movl (%%edi),%%edi ;"
  87                "movl %%ebx,%%ebp ; addl %3,%%ebp ; movl (%%ebp),%%ebp ;"
  88                "int $0x80 ;"
  89                "addl %4,%%ebx ; movl %%eax, (%%ebx) ;"
  90                "int $3"
  91                : :
  92                "g" (~(UM_KERN_PAGE_SIZE - 1)),
  93                "g" (STUB_MMAP_NR),
  94                "g" (UML_STUB_FIELD_FD),
  95                "g" (UML_STUB_FIELD_OFFSET),
  96                "g" (UML_STUB_FIELD_CHILD_ERR),
  97                "c" (UM_KERN_PAGE_SIZE),
  98                "d" (PROT_READ | PROT_WRITE),
  99                "S" (MAP_FIXED | MAP_SHARED)
 100                :
 101                "memory");
 102}
 103
 104static __always_inline void *get_stub_page(void)
 105{
 106        unsigned long ret;
 107
 108        asm volatile (
 109                "movl %%esp,%0 ;"
 110                "andl %1,%0"
 111                : "=a" (ret)
 112                : "g" (~(UM_KERN_PAGE_SIZE - 1)));
 113
 114        return (void *)ret;
 115}
 116#endif
 117