1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
4 */
5
6#include <linux/audit.h>
7#include <linux/ptrace.h>
8#include <linux/sched.h>
9#include <linux/uaccess.h>
10#include <asm/ptrace-abi.h>
11
12void user_enable_single_step(struct task_struct *child)
13{
14	set_tsk_thread_flag(child, TIF_SINGLESTEP);
15
16#ifdef SUBARCH_SET_SINGLESTEPPING
17	SUBARCH_SET_SINGLESTEPPING(child, 1);
18#endif
19}
20
21void user_disable_single_step(struct task_struct *child)
22{
23	clear_tsk_thread_flag(child, TIF_SINGLESTEP);
24
25#ifdef SUBARCH_SET_SINGLESTEPPING
26	SUBARCH_SET_SINGLESTEPPING(child, 0);
27#endif
28}
29
30/*
31 * Called by kernel/ptrace.c when detaching..
32 */
33void ptrace_disable(struct task_struct *child)
34{
35	user_disable_single_step(child);
36}
37
38extern int peek_user(struct task_struct * child, long addr, long data);
39extern int poke_user(struct task_struct * child, long addr, long data);
40
41long arch_ptrace(struct task_struct *child, long request,
42		 unsigned long addr, unsigned long data)
43{
44	int i, ret;
45	unsigned long __user *p = (void __user *)data;
46	void __user *vp = p;
47
48	switch (request) {
49	/* read the word at location addr in the USER area. */
50	case PTRACE_PEEKUSR:
51		ret = peek_user(child, addr, data);
52		break;
53
54	/* write the word at location addr in the USER area */
55	case PTRACE_POKEUSR:
56		ret = poke_user(child, addr, data);
57		break;
58
59	case PTRACE_SYSEMU:
60	case PTRACE_SYSEMU_SINGLESTEP:
61		ret = -EIO;
62		break;
63
64#ifdef PTRACE_GETREGS
65	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
66		if (!access_ok(p, MAX_REG_OFFSET)) {
67			ret = -EIO;
68			break;
69		}
70		for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
71			__put_user(getreg(child, i), p);
72			p++;
73		}
74		ret = 0;
75		break;
76	}
77#endif
78#ifdef PTRACE_SETREGS
79	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
80		unsigned long tmp = 0;
81		if (!access_ok(p, MAX_REG_OFFSET)) {
82			ret = -EIO;
83			break;
84		}
85		for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
86			__get_user(tmp, p);
87			putreg(child, i, tmp);
88			p++;
89		}
90		ret = 0;
91		break;
92	}
93#endif
94	case PTRACE_GET_THREAD_AREA:
95		ret = ptrace_get_thread_area(child, addr, vp);
96		break;
97
98	case PTRACE_SET_THREAD_AREA:
99		ret = ptrace_set_thread_area(child, addr, vp);
100		break;
101
102	default:
103		ret = ptrace_request(child, request, addr, data);
104		if (ret == -EIO)
105			ret = subarch_ptrace(child, request, addr, data);
106		break;
107	}
108
109	return ret;
110}
111
112static void send_sigtrap(struct uml_pt_regs *regs, int error_code)
113{
114	/* Send us the fake SIGTRAP */
115	force_sig_fault(SIGTRAP, TRAP_BRKPT,
116			/* User-mode eip? */
117			UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL);
118}
119
120/*
121 * XXX Check TIF_SINGLESTEP for singlestepping check and
122 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
123 */
124int syscall_trace_enter(struct pt_regs *regs)
125{
126	audit_syscall_entry(UPT_SYSCALL_NR(&regs->regs),
127			    UPT_SYSCALL_ARG1(&regs->regs),
128			    UPT_SYSCALL_ARG2(&regs->regs),
129			    UPT_SYSCALL_ARG3(&regs->regs),
130			    UPT_SYSCALL_ARG4(&regs->regs));
131
132	if (!test_thread_flag(TIF_SYSCALL_TRACE))
133		return 0;
134
135	return ptrace_report_syscall_entry(regs);
136}
137
138void syscall_trace_leave(struct pt_regs *regs)
139{
140	int ptraced = current->ptrace;
141
142	audit_syscall_exit(regs);
143
144	/* Fake a debug trap */
145	if (test_thread_flag(TIF_SINGLESTEP))
146		send_sigtrap(&regs->regs, 0);
147
148	if (!test_thread_flag(TIF_SYSCALL_TRACE))
149		return;
150
151	ptrace_report_syscall_exit(regs, 0);
152	/* force do_signal() --> is_syscall() */
153	if (ptraced & PT_PTRACED)
154		set_thread_flag(TIF_SIGPENDING);
155}
156