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
 22static 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 */
 68static 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 */
114enum nios2_regset {
115	REGSET_GENERAL,
116};
117
118static 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
129static 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
137const struct user_regset_view *task_user_regset_view(struct task_struct *task)
138{
139	return &nios2_user_view;
140}
141
142void ptrace_disable(struct task_struct *child)
143{
144
145}
146
147long 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
153asmlinkage 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
163asmlinkage 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}