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		       struct membuf to)
 25{
 26	const struct pt_regs *regs = task_pt_regs(target);
 27	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
 28
 29	membuf_zero(&to, 4); // R0
 30	membuf_write(&to, &regs->r1, 7 * 4); // R1..R7
 31	membuf_write(&to, &regs->r8, 8 * 4); // R8..R15
 32	membuf_write(&to, sw, 8 * 4); // R16..R23
 33	membuf_zero(&to, 2 * 4); /* et and bt */
 34	membuf_store(&to, regs->gp);
 35	membuf_store(&to, regs->sp);
 36	membuf_store(&to, regs->fp);
 37	membuf_store(&to, regs->ea);
 38	membuf_zero(&to, 4); // PTR_BA
 39	membuf_store(&to, regs->ra);
 40	membuf_store(&to, regs->ea); /* use ea for PC */
 41	return membuf_zero(&to, (NUM_PTRACE_REG - PTR_PC) * 4);
 42}
 43
 44/*
 45 * Set the thread state from a regset passed in via ptrace
 46 */
 47static int genregs_set(struct task_struct *target,
 48		       const struct user_regset *regset,
 49		       unsigned int pos, unsigned int count,
 50		       const void *kbuf, const void __user *ubuf)
 51{
 52	struct pt_regs *regs = task_pt_regs(target);
 53	const struct switch_stack *sw = (struct switch_stack *)regs - 1;
 54	int ret = 0;
 55
 56#define REG_IGNORE_RANGE(START, END)		\
 57	if (!ret)					\
 58		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
 59			START * 4, (END * 4) + 4);
 60
 61#define REG_IN_ONE(PTR, LOC)	\
 62	if (!ret)			\
 63		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
 64			(void *)(PTR), LOC * 4, (LOC * 4) + 4);
 65
 66#define REG_IN_RANGE(PTR, START, END)	\
 67	if (!ret)				\
 68		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
 69			(void *)(PTR), START * 4, (END * 4) + 4);
 70
 71	REG_IGNORE_RANGE(PTR_R0, PTR_R0);
 72	REG_IN_RANGE(&regs->r1, PTR_R1, PTR_R7);
 73	REG_IN_RANGE(&regs->r8, PTR_R8, PTR_R15);
 74	REG_IN_RANGE(sw, PTR_R16, PTR_R23);
 75	REG_IGNORE_RANGE(PTR_R24, PTR_R25); /* et and bt */
 76	REG_IN_ONE(&regs->gp, PTR_GP);
 77	REG_IN_ONE(&regs->sp, PTR_SP);
 78	REG_IN_ONE(&regs->fp, PTR_FP);
 79	REG_IN_ONE(&regs->ea, PTR_EA);
 80	REG_IGNORE_RANGE(PTR_BA, PTR_BA);
 81	REG_IN_ONE(&regs->ra, PTR_RA);
 82	REG_IN_ONE(&regs->ea, PTR_PC); /* use ea for PC */
 83	if (!ret)
 84		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
 85					 PTR_STATUS * 4, -1);
 86
 87	return ret;
 88}
 89
 90/*
 91 * Define the register sets available on Nios2 under Linux
 92 */
 93enum nios2_regset {
 94	REGSET_GENERAL,
 95};
 96
 97static const struct user_regset nios2_regsets[] = {
 98	[REGSET_GENERAL] = {
 99		.core_note_type = NT_PRSTATUS,
100		.n = NUM_PTRACE_REG,
101		.size = sizeof(unsigned long),
102		.align = sizeof(unsigned long),
103		.regset_get = genregs_get,
104		.set = genregs_set,
105	}
106};
107
108static const struct user_regset_view nios2_user_view = {
109	.name = "nios2",
110	.e_machine = ELF_ARCH,
111	.ei_osabi = ELF_OSABI,
112	.regsets = nios2_regsets,
113	.n = ARRAY_SIZE(nios2_regsets)
114};
115
116const struct user_regset_view *task_user_regset_view(struct task_struct *task)
117{
118	return &nios2_user_view;
119}
120
121void ptrace_disable(struct task_struct *child)
122{
123
124}
125
126long arch_ptrace(struct task_struct *child, long request, unsigned long addr,
127		 unsigned long data)
128{
129	return ptrace_request(child, request, addr, data);
130}
131
132asmlinkage int do_syscall_trace_enter(void)
133{
134	int ret = 0;
135
136	if (test_thread_flag(TIF_SYSCALL_TRACE))
137		ret = tracehook_report_syscall_entry(task_pt_regs(current));
138
139	return ret;
140}
141
142asmlinkage void do_syscall_trace_exit(void)
143{
144	if (test_thread_flag(TIF_SYSCALL_TRACE))
145		tracehook_report_syscall_exit(task_pt_regs(current), 0);
146}