xref: /linux/arch/x86/um/shared/sysdep/stub_64.h (revision e04e2b760ddbe3d7b283a05898c3a029085cd8cd)
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 <stddef.h>
10 #include <sysdep/ptrace_user.h>
11 #include <generated/asm-offsets.h>
12 #include <linux/stddef.h>
13 
14 #define STUB_MMAP_NR __NR_mmap
15 #define MMAP_OFFSET(o) (o)
16 
17 #define __syscall_clobber "r11","rcx","memory"
18 #define __syscall "syscall"
19 
20 static __always_inline long stub_syscall0(long syscall)
21 {
22 	long ret;
23 
24 	__asm__ volatile (__syscall
25 		: "=a" (ret)
26 		: "0" (syscall) : __syscall_clobber );
27 
28 	return ret;
29 }
30 
31 static __always_inline long stub_syscall2(long syscall, long arg1, long arg2)
32 {
33 	long ret;
34 
35 	__asm__ volatile (__syscall
36 		: "=a" (ret)
37 		: "0" (syscall), "D" (arg1), "S" (arg2) : __syscall_clobber );
38 
39 	return ret;
40 }
41 
42 static __always_inline long stub_syscall3(long syscall, long arg1, long arg2,
43 					  long arg3)
44 {
45 	long ret;
46 
47 	__asm__ volatile (__syscall
48 		: "=a" (ret)
49 		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3)
50 		: __syscall_clobber );
51 
52 	return ret;
53 }
54 
55 static __always_inline long stub_syscall4(long syscall, long arg1, long arg2, long arg3,
56 				 long arg4)
57 {
58 	long ret;
59 
60 	__asm__ volatile ("movq %5,%%r10 ; " __syscall
61 		: "=a" (ret)
62 		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
63 		  "g" (arg4)
64 		: __syscall_clobber, "r10" );
65 
66 	return ret;
67 }
68 
69 static __always_inline long stub_syscall5(long syscall, long arg1, long arg2,
70 					  long arg3, long arg4, long arg5)
71 {
72 	long ret;
73 
74 	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; " __syscall
75 		: "=a" (ret)
76 		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
77 		  "g" (arg4), "g" (arg5)
78 		: __syscall_clobber, "r10", "r8" );
79 
80 	return ret;
81 }
82 
83 static __always_inline long stub_syscall6(long syscall, long arg1, long arg2,
84 					  long arg3, long arg4, long arg5,
85 					  long arg6)
86 {
87 	long ret;
88 
89 	__asm__ volatile ("movq %5,%%r10 ; movq %6,%%r8 ; movq %7,%%r9 ; "
90 		__syscall
91 		: "=a" (ret)
92 		: "0" (syscall), "D" (arg1), "S" (arg2), "d" (arg3),
93 		  "g" (arg4), "g" (arg5), "g" (arg6)
94 		: __syscall_clobber, "r10", "r8", "r9");
95 
96 	return ret;
97 }
98 
99 static __always_inline void trap_myself(void)
100 {
101 	__asm("int3");
102 }
103 
104 static __always_inline void *get_stub_data(void)
105 {
106 	unsigned long ret;
107 
108 	asm volatile (
109 		"movq %%rsp,%0 ;"
110 		"andq %1,%0"
111 		: "=a" (ret)
112 		: "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)));
113 
114 	return (void *)ret;
115 }
116 #endif
117