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 15 static __always_inline long stub_syscall0(long syscall) 16 { 17 long ret; 18 19 __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall) 20 : "memory"); 21 22 return ret; 23 } 24 25 static __always_inline long stub_syscall1(long syscall, long arg1) 26 { 27 long ret; 28 29 __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1) 30 : "memory"); 31 32 return ret; 33 } 34 35 static __always_inline long stub_syscall2(long syscall, long arg1, long arg2) 36 { 37 long ret; 38 39 __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1), 40 "c" (arg2) 41 : "memory"); 42 43 return ret; 44 } 45 46 static __always_inline long stub_syscall3(long syscall, long arg1, long arg2, 47 long arg3) 48 { 49 long ret; 50 51 __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1), 52 "c" (arg2), "d" (arg3) 53 : "memory"); 54 55 return ret; 56 } 57 58 static __always_inline long stub_syscall4(long syscall, long arg1, long arg2, 59 long arg3, long arg4) 60 { 61 long ret; 62 63 __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1), 64 "c" (arg2), "d" (arg3), "S" (arg4) 65 : "memory"); 66 67 return ret; 68 } 69 70 static __always_inline long stub_syscall5(long syscall, long arg1, long arg2, 71 long arg3, long arg4, long arg5) 72 { 73 long ret; 74 75 __asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1), 76 "c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5) 77 : "memory"); 78 79 return ret; 80 } 81 82 static __always_inline void trap_myself(void) 83 { 84 __asm("int3"); 85 } 86 87 static __always_inline void remap_stack_and_trap(void) 88 { 89 __asm__ volatile ( 90 "movl %%esp,%%ebx ;" 91 "andl %0,%%ebx ;" 92 "movl %1,%%eax ;" 93 "movl %%ebx,%%edi ; addl %2,%%edi ; movl (%%edi),%%edi ;" 94 "movl %%ebx,%%ebp ; addl %3,%%ebp ; movl (%%ebp),%%ebp ;" 95 "int $0x80 ;" 96 "addl %4,%%ebx ; movl %%eax, (%%ebx) ;" 97 "int $3" 98 : : 99 "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)), 100 "g" (STUB_MMAP_NR), 101 "g" (UML_STUB_FIELD_FD), 102 "g" (UML_STUB_FIELD_OFFSET), 103 "g" (UML_STUB_FIELD_CHILD_ERR), 104 "c" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE), 105 "d" (PROT_READ | PROT_WRITE), 106 "S" (MAP_FIXED | MAP_SHARED) 107 : 108 "memory"); 109 } 110 111 static __always_inline void *get_stub_data(void) 112 { 113 unsigned long ret; 114 115 asm volatile ( 116 "movl %%esp,%0 ;" 117 "andl %1,%0" 118 : "=a" (ret) 119 : "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1))); 120 121 return (void *)ret; 122 } 123 #endif 124