xref: /linux/arch/um/os-Linux/registers.c (revision 3d0fe49454652117522f60bfbefb978ba0e5300b)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Copyright (C) 2004 PathScale, Inc
4  * Copyright (C) 2004 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
5  */
6 
7 #include <errno.h>
8 #include <string.h>
9 #include <sys/ptrace.h>
10 #include <sysdep/ptrace.h>
11 #include <sysdep/ptrace_user.h>
12 #include <registers.h>
13 
14 int save_registers(int pid, struct uml_pt_regs *regs)
15 {
16 	int err;
17 
18 	err = ptrace(PTRACE_GETREGS, pid, 0, regs->gp);
19 	if (err < 0)
20 		return -errno;
21 	return 0;
22 }
23 
24 int restore_pid_registers(int pid, struct uml_pt_regs *regs)
25 {
26 	int err;
27 
28 	err = ptrace(PTRACE_SETREGS, pid, 0, regs->gp);
29 	if (err < 0)
30 		return -errno;
31 	return 0;
32 }
33 
34 /* This is set once at boot time and not changed thereafter */
35 
36 static unsigned long exec_regs[MAX_REG_NR];
37 static unsigned long exec_fp_regs[FP_SIZE];
38 
39 int init_pid_registers(int pid)
40 {
41 	int err;
42 
43 	err = ptrace(PTRACE_GETREGS, pid, 0, exec_regs);
44 	if (err < 0)
45 		return -errno;
46 
47 	arch_init_registers(pid);
48 	get_fp_registers(pid, exec_fp_regs);
49 	return 0;
50 }
51 
52 void get_safe_registers(unsigned long *regs, unsigned long *fp_regs)
53 {
54 	memcpy(regs, exec_regs, sizeof(exec_regs));
55 
56 	if (fp_regs)
57 		memcpy(fp_regs, exec_fp_regs, sizeof(exec_fp_regs));
58 }
59