xref: /openbmc/linux/arch/x86/um/shared/sysdep/stub_64.h (revision d9fd5a71)
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 
12 #define STUB_MMAP_NR __NR_mmap
13 #define MMAP_OFFSET(o) (o)
14 
15 #define __syscall_clobber "r11","rcx","memory"
16 #define __syscall "syscall"
17 
18 static inline long stub_syscall0(long syscall)
19 {
20 	long ret;
21 
22 	__asm__ volatile (__syscall
23 		: "=a" (ret)
24 		: "0" (syscall) : __syscall_clobber );
25 
26 	return ret;
27 }
28 
29 static inline long stub_syscall2(long syscall, long arg1, long arg2)
30 {
31 	long ret;
32 
33 	__asm__ volatile (__syscall
34 		: "=a" (ret)
35 		: "0" (syscall), "D" (arg1), "S" (arg2) : __syscall_clobber );
36 
37 	return ret;
38 }
39 
40 static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
41 {
42 	long ret;
43 
44 	__asm__ volatile (__syscall
45 		: "=a" (ret)
46 		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3)
47 		: __syscall_clobber );
48 
49 	return ret;
50 }
51 
52 static inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
53 				 long arg4)
54 {
55 	long ret;
56 
57 	__asm__ volatile ("movq %5,%%r10 ; " __syscall
58 		: "=a" (ret)
59 		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
60 		  "g" (arg4)
61 		: __syscall_clobber, "r10" );
62 
63 	return ret;
64 }
65 
66 static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
67 				 long arg4, long arg5)
68 {
69 	long ret;
70 
71 	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; " __syscall
72 		: "=a" (ret)
73 		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
74 		  "g" (arg4), "g" (arg5)
75 		: __syscall_clobber, "r10", "r8" );
76 
77 	return ret;
78 }
79 
80 static inline void trap_myself(void)
81 {
82 	__asm("int3");
83 }
84 
85 static inline void remap_stack_and_trap(void)
86 {
87 	__asm__ volatile (
88 		"movq %0,%%rax ;"
89 		"movq %%rsp,%%rdi ;"
90 		"andq %1,%%rdi ;"
91 		"movq %2,%%r10 ;"
92 		"movq %%rdi,%%r8 ; addq %3,%%r8 ; movq (%%r8),%%r8 ;"
93 		"movq %%rdi,%%r9 ; addq %4,%%r9 ; movq (%%r9),%%r9 ;"
94 		__syscall ";"
95 		"movq %%rsp,%%rdi ; andq %1,%%rdi ;"
96 		"addq %5,%%rdi ; movq %%rax, (%%rdi) ;"
97 		"int3"
98 		: :
99 		"g" (STUB_MMAP_NR),
100 		"g" (~(UM_KERN_PAGE_SIZE - 1)),
101 		"g" (MAP_FIXED | MAP_SHARED),
102 		"g" (UML_STUB_FIELD_FD),
103 		"g" (UML_STUB_FIELD_OFFSET),
104 		"g" (UML_STUB_FIELD_CHILD_ERR),
105 		"S" (UM_KERN_PAGE_SIZE),
106 		"d" (PROT_READ | PROT_WRITE)
107 		:
108 		__syscall_clobber, "r10", "r8", "r9");
109 }
110 
111 #endif
112