1/*
  2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  3 * Copyright 2015 Regents of the University of California
  4 * Copyright 2017 SiFive
  5 *
  6 *   This program is free software; you can redistribute it and/or
  7 *   modify it under the terms of the GNU General Public License
  8 *   as published by the Free Software Foundation, version 2.
  9 *
 10 *   This program is distributed in the hope that it will be useful,
 11 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 12 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 13 *   GNU General Public License for more details.
 14 *
 15 * Copied from arch/tile/kernel/ptrace.c
 16 */
 17
 18#include <asm/ptrace.h>
 19#include <asm/syscall.h>
 20#include <asm/thread_info.h>
 21#include <linux/ptrace.h>
 22#include <linux/elf.h>
 23#include <linux/regset.h>
 24#include <linux/sched.h>
 25#include <linux/sched/task_stack.h>
 26#include <linux/tracehook.h>
 27#include <trace/events/syscalls.h>
 28
 29enum riscv_regset {
 30	REGSET_X,
 31};
 32
 33static int riscv_gpr_get(struct task_struct *target,
 34			 const struct user_regset *regset,
 35			 unsigned int pos, unsigned int count,
 36			 void *kbuf, void __user *ubuf)
 37{
 38	struct pt_regs *regs;
 39
 40	regs = task_pt_regs(target);
 41	return user_regset_copyout(&pos, &count, &kbuf, &ubuf, regs, 0, -1);
 42}
 43
 44static int riscv_gpr_set(struct task_struct *target,
 45			 const struct user_regset *regset,
 46			 unsigned int pos, unsigned int count,
 47			 const void *kbuf, const void __user *ubuf)
 48{
 49	int ret;
 50	struct pt_regs *regs;
 51
 52	regs = task_pt_regs(target);
 53	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &regs, 0, -1);
 54	return ret;
 55}
 56
 57
 58static const struct user_regset riscv_user_regset[] = {
 59	[REGSET_X] = {
 60		.core_note_type = NT_PRSTATUS,
 61		.n = ELF_NGREG,
 62		.size = sizeof(elf_greg_t),
 63		.align = sizeof(elf_greg_t),
 64		.get = &riscv_gpr_get,
 65		.set = &riscv_gpr_set,
 66	},
 67};
 68
 69static const struct user_regset_view riscv_user_native_view = {
 70	.name = "riscv",
 71	.e_machine = EM_RISCV,
 72	.regsets = riscv_user_regset,
 73	.n = ARRAY_SIZE(riscv_user_regset),
 74};
 75
 76const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 77{
 78	return &riscv_user_native_view;
 79}
 80
 81void ptrace_disable(struct task_struct *child)
 82{
 83	clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 84}
 85
 86long arch_ptrace(struct task_struct *child, long request,
 87		 unsigned long addr, unsigned long data)
 88{
 89	long ret = -EIO;
 90
 91	switch (request) {
 92	default:
 93		ret = ptrace_request(child, request, addr, data);
 94		break;
 95	}
 96
 97	return ret;
 98}
 99
100/*
101 * Allows PTRACE_SYSCALL to work.  These are called from entry.S in
102 * {handle,ret_from}_syscall.
103 */
104void do_syscall_trace_enter(struct pt_regs *regs)
105{
106	if (test_thread_flag(TIF_SYSCALL_TRACE))
107		if (tracehook_report_syscall_entry(regs))
108			syscall_set_nr(current, regs, -1);
109
110#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
111	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
112		trace_sys_enter(regs, syscall_get_nr(current, regs));
113#endif
114}
115
116void do_syscall_trace_exit(struct pt_regs *regs)
117{
118	if (test_thread_flag(TIF_SYSCALL_TRACE))
119		tracehook_report_syscall_exit(regs, 0);
120
121#ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
122	if (test_thread_flag(TIF_SYSCALL_TRACEPOINT))
123		trace_sys_exit(regs, regs->regs[0]);
124#endif
125}