xref: /openbmc/linux/arch/x86/um/shared/sysdep/stub_32.h (revision ffcdf473)
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 <asm/ptrace.h>
10 #include <generated/asm-offsets.h>
11 
12 #define STUB_MMAP_NR __NR_mmap2
13 #define MMAP_OFFSET(o) ((o) >> UM_KERN_PAGE_SHIFT)
14 
15 static inline long stub_syscall0(long syscall)
16 {
17 	long ret;
18 
19 	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall));
20 
21 	return ret;
22 }
23 
24 static inline long stub_syscall1(long syscall, long arg1)
25 {
26 	long ret;
27 
28 	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1));
29 
30 	return ret;
31 }
32 
33 static inline long stub_syscall2(long syscall, long arg1, long arg2)
34 {
35 	long ret;
36 
37 	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
38 			"c" (arg2));
39 
40 	return ret;
41 }
42 
43 static inline long stub_syscall3(long syscall, long arg1, long arg2, long arg3)
44 {
45 	long ret;
46 
47 	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
48 			"c" (arg2), "d" (arg3));
49 
50 	return ret;
51 }
52 
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 ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
59 			"c" (arg2), "d" (arg3), "S" (arg4));
60 
61 	return ret;
62 }
63 
64 static inline long stub_syscall5(long syscall, long arg1, long arg2, long arg3,
65 				 long arg4, long arg5)
66 {
67 	long ret;
68 
69 	__asm__ volatile ("int $0x80" : "=a" (ret) : "0" (syscall), "b" (arg1),
70 			"c" (arg2), "d" (arg3), "S" (arg4), "D" (arg5));
71 
72 	return ret;
73 }
74 
75 static inline void trap_myself(void)
76 {
77 	__asm("int3");
78 }
79 
80 static inline void remap_stack_and_trap(void)
81 {
82 	__asm__ volatile (
83 		"movl %%esp,%%ebx ;"
84 		"andl %0,%%ebx ;"
85 		"movl %1,%%eax ;"
86 		"movl %%ebx,%%edi ; addl %2,%%edi ; movl (%%edi),%%edi ;"
87 		"movl %%ebx,%%ebp ; addl %3,%%ebp ; movl (%%ebp),%%ebp ;"
88 		"int $0x80 ;"
89 		"addl %4,%%ebx ; movl %%eax, (%%ebx) ;"
90 		"int $3"
91 		: :
92 		"g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)),
93 		"g" (STUB_MMAP_NR),
94 		"g" (UML_STUB_FIELD_FD),
95 		"g" (UML_STUB_FIELD_OFFSET),
96 		"g" (UML_STUB_FIELD_CHILD_ERR),
97 		"c" (STUB_DATA_PAGES * UM_KERN_PAGE_SIZE),
98 		"d" (PROT_READ | PROT_WRITE),
99 		"S" (MAP_FIXED | MAP_SHARED)
100 		:
101 		"memory");
102 }
103 
104 static __always_inline void *get_stub_data(void)
105 {
106 	unsigned long ret;
107 
108 	asm volatile (
109 		"movl %%esp,%0 ;"
110 		"andl %1,%0"
111 		: "=a" (ret)
112 		: "g" (~(STUB_DATA_PAGES * UM_KERN_PAGE_SIZE - 1)));
113 
114 	return (void *)ret;
115 }
116 #endif
117