xref: /openbmc/linux/arch/x86/um/shared/sysdep/stub_64.h (revision 9cfc5c90)
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 
11 #define STUB_SYSCALL_RET PT_INDEX(RAX)
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(long fd, unsigned long offset)
86 {
87 	__asm__ volatile ("movq %4,%%r10 ; movq %5,%%r8 ; "
88 			  "movq %6, %%r9; " __syscall "; movq %7, %%rbx ; "
89 			  "movq %%rax, (%%rbx)":
90 			  : "a" (STUB_MMAP_NR), "D" (STUB_DATA),
91 			    "S" (UM_KERN_PAGE_SIZE),
92 			    "d" (PROT_READ | PROT_WRITE),
93                             "g" (MAP_FIXED | MAP_SHARED), "g" (fd),
94 			    "g" (offset),
95 			    "i" (&((struct stub_data *) STUB_DATA)->err)
96 			  : __syscall_clobber, "r10", "r8", "r9" );
97 }
98 
99 #endif
100