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 <sysdep/ptrace_user.h> 10 #include <generated/asm-offsets.h> 11 #include <linux/stddef.h> 12 13 #define STUB_MMAP_NR __NR_mmap 14 #define MMAP_OFFSET(o) (o) 15 16 #define __syscall_clobber "r11","rcx","memory" 17 #define __syscall "syscall" 18 19 static __always_inline long stub_syscall0(long syscall) 20 { 21 long ret; 22 23 __asm__ volatile (__syscall 24 : "=a" (ret) 25 : "0" (syscall) : __syscall_clobber ); 26 27 return ret; 28 } 29 30 static __always_inline long stub_syscall2(long syscall, long arg1, long arg2) 31 { 32 long ret; 33 34 __asm__ volatile (__syscall 35 : "=a" (ret) 36 : "0" (syscall), "D" (arg1), "S" (arg2) : __syscall_clobber ); 37 38 return ret; 39 } 40 41 static __always_inline long stub_syscall3(long syscall, long arg1, long arg2, 42 long arg3) 43 { 44 long ret; 45 46 __asm__ volatile (__syscall 47 : "=a" (ret) 48 : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3) 49 : __syscall_clobber ); 50 51 return ret; 52 } 53 54 static __always_inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3, 55 long arg4) 56 { 57 long ret; 58 59 __asm__ volatile ("movq %5,%%r10 ; " __syscall 60 : "=a" (ret) 61 : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3), 62 "g" (arg4) 63 : __syscall_clobber, "r10" ); 64 65 return ret; 66 } 67 68 static __always_inline long stub_syscall5(long syscall, long arg1, long arg2, 69 long arg3, long arg4, long arg5) 70 { 71 long ret; 72 73 __asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; " __syscall 74 : "=a" (ret) 75 : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3), 76 "g" (arg4), "g" (arg5) 77 : __syscall_clobber, "r10", "r8" ); 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 "movq %0,%%rax ;" 91 "movq %%rsp,%%rdi ;" 92 "andq %1,%%rdi ;" 93 "movq %2,%%r10 ;" 94 "movq %%rdi,%%r8 ; addq %3,%%r8 ; movq (%%r8),%%r8 ;" 95 "movq %%rdi,%%r9 ; addq %4,%%r9 ; movq (%%r9),%%r9 ;" 96 __syscall ";" 97 "movq %%rsp,%%rdi ; andq %1,%%rdi ;" 98 "addq %5,%%rdi ; movq %%rax, (%%rdi) ;" 99 "int3" 100 : : 101 "g" (STUB_MMAP_NR), 102 "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)), 103 "g" (MAP_FIXED | MAP_SHARED), 104 "g" (UML_STUB_FIELD_FD), 105 "g" (UML_STUB_FIELD_OFFSET), 106 "g" (UML_STUB_FIELD_CHILD_ERR), 107 "S" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE), 108 "d" (PROT_READ | PROT_WRITE) 109 : 110 __syscall_clobber, "r10", "r8", "r9"); 111 } 112 113 static __always_inline void *get_stub_data(void) 114 { 115 unsigned long ret; 116 117 asm volatile ( 118 "movq %%rsp,%0 ;" 119 "andq %1,%0" 120 : "=a" (ret) 121 : "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1))); 122 123 return (void *)ret; 124 } 125 #endif 126