xref: /openbmc/linux/arch/nios2/kernel/ptrace.c (revision fb574682)
1 /*
2  * Copyright (C) 2014 Altera Corporation
3  * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
4  *
5  * This file is subject to the terms and conditions of the GNU General
6  * Public License.  See the file COPYING in the main directory of this
7  * archive for more details.
8  */
9 
10 #include <linux/elf.h>
11 #include <linux/errno.h>
12 #include <linux/kernel.h>
13 #include <linux/mm.h>
14 #include <linux/ptrace.h>
15 #include <linux/regset.h>
16 #include <linux/sched.h>
17 #include <linux/sched/task_stack.h>
18 #include <linux/tracehook.h>
19 #include <linux/uaccess.h>
20 #include <linux/user.h>
21 
22 static int genregs_get(struct task_struct *target,
23 		       const struct user_regset *regset,
24 		       unsigned int pos, unsigned int count,
25 		       void *kbuf, void __user *ubuf)
26 {
27 	const struct pt_regs *regs = task_pt_regs(target);
28 	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
29 	int ret = 0;
30 
31 #define REG_O_ZERO_RANGE(START, END)		\
32 	if (!ret)					\
33 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
34 			START * 4, (END * 4) + 4);
35 
36 #define REG_O_ONE(PTR, LOC)	\
37 	if (!ret)			\
38 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
39 			LOC * 4, (LOC * 4) + 4);
40 
41 #define REG_O_RANGE(PTR, START, END)	\
42 	if (!ret)				\
43 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
44 			START * 4, (END * 4) + 4);
45 
46 	REG_O_ZERO_RANGE(PTR_R0, PTR_R0);
47 	REG_O_RANGE(&regs->r1, PTR_R1, PTR_R7);
48 	REG_O_RANGE(&regs->r8, PTR_R8, PTR_R15);
49 	REG_O_RANGE(sw, PTR_R16, PTR_R23);
50 	REG_O_ZERO_RANGE(PTR_R24, PTR_R25); /* et and bt */
51 	REG_O_ONE(&regs->gp, PTR_GP);
52 	REG_O_ONE(&regs->sp, PTR_SP);
53 	REG_O_ONE(&regs->fp, PTR_FP);
54 	REG_O_ONE(&regs->ea, PTR_EA);
55 	REG_O_ZERO_RANGE(PTR_BA, PTR_BA);
56 	REG_O_ONE(&regs->ra, PTR_RA);
57 	REG_O_ONE(&regs->ea, PTR_PC); /* use ea for PC */
58 	if (!ret)
59 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
60 					 PTR_STATUS * 4, -1);
61 
62 	return ret;
63 }
64 
65 /*
66  * Set the thread state from a regset passed in via ptrace
67  */
68 static int genregs_set(struct task_struct *target,
69 		       const struct user_regset *regset,
70 		       unsigned int pos, unsigned int count,
71 		       const void *kbuf, const void __user *ubuf)
72 {
73 	struct pt_regs *regs = task_pt_regs(target);
74 	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
75 	int ret = 0;
76 
77 #define REG_IGNORE_RANGE(START, END)		\
78 	if (!ret)					\
79 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
80 			START * 4, (END * 4) + 4);
81 
82 #define REG_IN_ONE(PTR, LOC)	\
83 	if (!ret)			\
84 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
85 			(void *)(PTR), LOC * 4, (LOC * 4) + 4);
86 
87 #define REG_IN_RANGE(PTR, START, END)	\
88 	if (!ret)				\
89 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
90 			(void *)(PTR), START * 4, (END * 4) + 4);
91 
92 	REG_IGNORE_RANGE(PTR_R0, PTR_R0);
93 	REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
94 	REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
95 	REG_IN_RANGE(sw, PTR_R16, PTR_R23);
96 	REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
97 	REG_IN_ONE(&regs->gp, PTR_GP);
98 	REG_IN_ONE(&regs->sp, PTR_SP);
99 	REG_IN_ONE(&regs->fp, PTR_FP);
100 	REG_IN_ONE(&regs->ea, PTR_EA);
101 	REG_IGNORE_RANGE(PTR_BA, PTR_BA);
102 	REG_IN_ONE(&regs->ra, PTR_RA);
103 	REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
104 	if (!ret)
105 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
106 					 PTR_STATUS * 4, -1);
107 
108 	return ret;
109 }
110 
111 /*
112  * Define the register sets available on Nios2 under Linux
113  */
114 enum nios2_regset {
115 	REGSET_GENERAL,
116 };
117 
118 static const struct user_regset nios2_regsets[] = {
119 	[REGSET_GENERAL] = {
120 		.core_note_type = NT_PRSTATUS,
121 		.n = NUM_PTRACE_REG,
122 		.size = sizeof(unsigned long),
123 		.align = sizeof(unsigned long),
124 		.get = genregs_get,
125 		.set = genregs_set,
126 	}
127 };
128 
129 static const struct user_regset_view nios2_user_view = {
130 	.name = "nios2",
131 	.e_machine = ELF_ARCH,
132 	.ei_osabi = ELF_OSABI,
133 	.regsets = nios2_regsets,
134 	.n = ARRAY_SIZE(nios2_regsets)
135 };
136 
137 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
138 {
139 	return &nios2_user_view;
140 }
141 
142 void ptrace_disable(struct task_struct *child)
143 {
144 
145 }
146 
147 long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
148 		 unsigned long data)
149 {
150 	return ptrace_request(child, request, addr, data);
151 }
152 
153 asmlinkage int do_syscall_trace_enter(void)
154 {
155 	int ret = 0;
156 
157 	if (test_thread_flag(TIF_SYSCALL_TRACE))
158 		ret = tracehook_report_syscall_entry(task_pt_regs(current));
159 
160 	return ret;
161 }
162 
163 asmlinkage void do_syscall_trace_exit(void)
164 {
165 	if (test_thread_flag(TIF_SYSCALL_TRACE))
166 		tracehook_report_syscall_exit(task_pt_regs(current), 0);
167 }
168