xref: /openbmc/linux/arch/nios2/kernel/ptrace.c (revision 8684014d)
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/tracehook.h>
18 #include <linux/uaccess.h>
19 #include <linux/user.h>
20 
21 static int genregs_get(struct task_struct *target,
22 		       const struct user_regset *regset,
23 		       unsigned int pos, unsigned int count,
24 		       void *kbuf, void __user *ubuf)
25 {
26 	const struct pt_regs *regs = task_pt_regs(target);
27 	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
28 	int ret = 0;
29 
30 #define REG_O_ZERO_RANGE(START, END)		\
31 	if (!ret)					\
32 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
33 			START * 4, (END * 4) + 4);
34 
35 #define REG_O_ONE(PTR, LOC)	\
36 	if (!ret)			\
37 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
38 			LOC * 4, (LOC * 4) + 4);
39 
40 #define REG_O_RANGE(PTR, START, END)	\
41 	if (!ret)				\
42 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
43 			START * 4, (END * 4) + 4);
44 
45 	REG_O_ZERO_RANGE(PTR_R0, PTR_R0);
46 	REG_O_RANGE(&regs->r1, PTR_R1, PTR_R7);
47 	REG_O_RANGE(&regs->r8, PTR_R8, PTR_R15);
48 	REG_O_RANGE(sw, PTR_R16, PTR_R23);
49 	REG_O_ZERO_RANGE(PTR_R24, PTR_R25); /* et and bt */
50 	REG_O_ONE(&regs->gp, PTR_GP);
51 	REG_O_ONE(&regs->sp, PTR_SP);
52 	REG_O_ONE(&regs->fp, PTR_FP);
53 	REG_O_ONE(&regs->ea, PTR_EA);
54 	REG_O_ZERO_RANGE(PTR_BA, PTR_BA);
55 	REG_O_ONE(&regs->ra, PTR_RA);
56 	REG_O_ONE(&regs->ea, PTR_PC); /* use ea for PC */
57 	if (!ret)
58 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
59 					 PTR_STATUS * 4, -1);
60 
61 	return ret;
62 }
63 
64 /*
65  * Set the thread state from a regset passed in via ptrace
66  */
67 static int genregs_set(struct task_struct *target,
68 		       const struct user_regset *regset,
69 		       unsigned int pos, unsigned int count,
70 		       const void *kbuf, const void __user *ubuf)
71 {
72 	struct pt_regs *regs = task_pt_regs(target);
73 	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
74 	int ret = 0;
75 
76 #define REG_IGNORE_RANGE(START, END)		\
77 	if (!ret)					\
78 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
79 			START * 4, (END * 4) + 4);
80 
81 #define REG_IN_ONE(PTR, LOC)	\
82 	if (!ret)			\
83 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
84 			(void *)(PTR), LOC * 4, (LOC * 4) + 4);
85 
86 #define REG_IN_RANGE(PTR, START, END)	\
87 	if (!ret)				\
88 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
89 			(void *)(PTR), START * 4, (END * 4) + 4);
90 
91 	REG_IGNORE_RANGE(PTR_R0, PTR_R0);
92 	REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
93 	REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
94 	REG_IN_RANGE(sw, PTR_R16, PTR_R23);
95 	REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
96 	REG_IN_ONE(&regs->gp, PTR_GP);
97 	REG_IN_ONE(&regs->sp, PTR_SP);
98 	REG_IN_ONE(&regs->fp, PTR_FP);
99 	REG_IN_ONE(&regs->ea, PTR_EA);
100 	REG_IGNORE_RANGE(PTR_BA, PTR_BA);
101 	REG_IN_ONE(&regs->ra, PTR_RA);
102 	REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
103 	if (!ret)
104 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
105 					 PTR_STATUS * 4, -1);
106 
107 	return ret;
108 }
109 
110 /*
111  * Define the register sets available on Nios2 under Linux
112  */
113 enum nios2_regset {
114 	REGSET_GENERAL,
115 };
116 
117 static const struct user_regset nios2_regsets[] = {
118 	[REGSET_GENERAL] = {
119 		.core_note_type = NT_PRSTATUS,
120 		.n = NUM_PTRACE_REG,
121 		.size = sizeof(unsigned long),
122 		.align = sizeof(unsigned long),
123 		.get = genregs_get,
124 		.set = genregs_set,
125 	}
126 };
127 
128 static const struct user_regset_view nios2_user_view = {
129 	.name = "nios2",
130 	.e_machine = ELF_ARCH,
131 	.ei_osabi = ELF_OSABI,
132 	.regsets = nios2_regsets,
133 	.n = ARRAY_SIZE(nios2_regsets)
134 };
135 
136 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
137 {
138 	return &nios2_user_view;
139 }
140 
141 void ptrace_disable(struct task_struct *child)
142 {
143 
144 }
145 
146 long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
147 		 unsigned long data)
148 {
149 	return ptrace_request(child, request, addr, data);
150 }
151 
152 asmlinkage int do_syscall_trace_enter(void)
153 {
154 	int ret = 0;
155 
156 	if (test_thread_flag(TIF_SYSCALL_TRACE))
157 		ret = tracehook_report_syscall_entry(task_pt_regs(current));
158 
159 	return ret;
160 }
161 
162 asmlinkage void do_syscall_trace_exit(void)
163 {
164 	if (test_thread_flag(TIF_SYSCALL_TRACE))
165 		tracehook_report_syscall_exit(task_pt_regs(current), 0);
166 }
167