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
stub_syscall0(long syscall)19 static 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
stub_syscall2(long syscall,long arg1,long arg2)30 static 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
stub_syscall3(long syscall,long arg1,long arg2,long arg3)41 static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
42 {
43 long ret;
44
45 __asm__ volatile (__syscall
46 : "=a" (ret)
47 : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3)
48 : __syscall_clobber );
49
50 return ret;
51 }
52
stub_syscall4(long syscall,long arg1,long arg2,long arg3,long arg4)53 static inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
54 long arg4)
55 {
56 long ret;
57
58 __asm__ volatile ("movq %5,%%r10 ; " __syscall
59 : "=a" (ret)
60 : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
61 "g" (arg4)
62 : __syscall_clobber, "r10" );
63
64 return ret;
65 }
66
stub_syscall5(long syscall,long arg1,long arg2,long arg3,long arg4,long arg5)67 static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
68 long arg4, long arg5)
69 {
70 long ret;
71
72 __asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; " __syscall
73 : "=a" (ret)
74 : "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
75 "g" (arg4), "g" (arg5)
76 : __syscall_clobber, "r10", "r8" );
77
78 return ret;
79 }
80
trap_myself(void)81 static inline void trap_myself(void)
82 {
83 __asm("int3");
84 }
85
remap_stack_and_trap(void)86 static inline void remap_stack_and_trap(void)
87 {
88 __asm__ volatile (
89 "movq %0,%%rax ;"
90 "movq %%rsp,%%rdi ;"
91 "andq %1,%%rdi ;"
92 "movq %2,%%r10 ;"
93 "movq %%rdi,%%r8 ; addq %3,%%r8 ; movq (%%r8),%%r8 ;"
94 "movq %%rdi,%%r9 ; addq %4,%%r9 ; movq (%%r9),%%r9 ;"
95 __syscall ";"
96 "movq %%rsp,%%rdi ; andq %1,%%rdi ;"
97 "addq %5,%%rdi ; movq %%rax, (%%rdi) ;"
98 "int3"
99 : :
100 "g" (STUB_MMAP_NR),
101 "g" (~(UM_KERN_PAGE_SIZE - 1)),
102 "g" (MAP_FIXED | MAP_SHARED),
103 "g" (UML_STUB_FIELD_FD),
104 "g" (UML_STUB_FIELD_OFFSET),
105 "g" (UML_STUB_FIELD_CHILD_ERR),
106 "S" (UM_KERN_PAGE_SIZE),
107 "d" (PROT_READ | PROT_WRITE)
108 :
109 __syscall_clobber, "r10", "r8", "r9");
110 }
111
get_stub_page(void)112 static __always_inline void *get_stub_page(void)
113 {
114 unsigned long ret;
115
116 asm volatile (
117 "movq %%rsp,%0 ;"
118 "andq %1,%0"
119 : "=a" (ret)
120 : "g" (~(UM_KERN_PAGE_SIZE - 1)));
121
122 return (void *)ret;
123 }
124 #endif
125