1/*
2 * Copyright (C) 2004 PathScale, Inc
3 * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 * Licensed under the GPL
5 */
6
7#include <errno.h>
8#include <stdlib.h>
9#include <sys/ptrace.h>
10#ifdef __i386__
11#include <sys/user.h>
12#endif
13#include <longjmp.h>
14#include <sysdep/ptrace_user.h>
15#include <sys/uio.h>
16#include <asm/sigcontext.h>
17#include <linux/elf.h>
18#include <registers.h>
19#include <sys/mman.h>
20
21static unsigned long ptrace_regset;
22unsigned long host_fp_size;
23
24int get_fp_registers(int pid, unsigned long *regs)
25{
26 struct iovec iov = {
27 .iov_base = regs,
28 .iov_len = host_fp_size,
29 };
30
31 if (ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov) < 0)
32 return -errno;
33 return 0;
34}
35
36int put_fp_registers(int pid, unsigned long *regs)
37{
38 struct iovec iov = {
39 .iov_base = regs,
40 .iov_len = host_fp_size,
41 };
42
43 if (ptrace(PTRACE_SETREGSET, pid, ptrace_regset, &iov) < 0)
44 return -errno;
45 return 0;
46}
47
48int arch_init_registers(int pid)
49{
50 struct iovec iov = {
51 /* Just use plenty of space, it does not cost us anything */
52 .iov_len = 2 * 1024 * 1024,
53 };
54 int ret;
55
56 iov.iov_base = mmap(NULL, iov.iov_len, PROT_WRITE | PROT_READ,
57 MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
58 if (iov.iov_base == MAP_FAILED)
59 return -ENOMEM;
60
61 /* GDB has x86_xsave_length, which uses x86_cpuid_count */
62 ptrace_regset = NT_X86_XSTATE;
63 ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
64 if (ret)
65 ret = -errno;
66
67 if (ret == -ENODEV) {
68#ifdef CONFIG_X86_32
69 ptrace_regset = NT_PRXFPREG;
70#else
71 ptrace_regset = NT_PRFPREG;
72#endif
73 iov.iov_len = 2 * 1024 * 1024;
74 ret = ptrace(PTRACE_GETREGSET, pid, ptrace_regset, &iov);
75 if (ret)
76 ret = -errno;
77 }
78
79 munmap(iov.iov_base, 2 * 1024 * 1024);
80
81 host_fp_size = iov.iov_len;
82
83 return ret;
84}
85
86unsigned long get_thread_reg(int reg, jmp_buf *buf)
87{
88 switch (reg) {
89#ifdef __i386__
90 case HOST_IP:
91 return buf[0]->__eip;
92 case HOST_SP:
93 return buf[0]->__esp;
94 case HOST_BP:
95 return buf[0]->__ebp;
96#else
97 case HOST_IP:
98 return buf[0]->__rip;
99 case HOST_SP:
100 return buf[0]->__rsp;
101 case HOST_BP:
102 return buf[0]->__rbp;
103#endif
104 default:
105 printk(UM_KERN_ERR "get_thread_regs - unknown register %d\n",
106 reg);
107 return 0;
108 }
109}
110

source code of linux/arch/x86/um/os-Linux/registers.c