xref: /linux/arch/x86/um/os-Linux/registers.c (revision ad73b9a17d66366d8c9198bc90f1ea99f24a912c)
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 
21 static unsigned long ptrace_regset;
22 unsigned long host_fp_size;
23 
get_fp_registers(int pid,unsigned long * regs)24 int 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 
put_fp_registers(int pid,unsigned long * regs)36 int 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 
arch_init_registers(int pid)48 int 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 
get_thread_reg(int reg,jmp_buf * buf)86 unsigned 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