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
 38long arch_ptrace(struct task_struct *child, long request,
 39		 unsigned long addr, unsigned long data)
 40{
 41	int i, ret;
 42	unsigned long __user *p = (void __user *)data;
 43	void __user *vp = p;
 44
 45	switch (request) {
 46	/* read the word at location addr in the USER area. */
 47	case PTRACE_PEEKUSR:
 48		ret = peek_user(child, addr, data);
 49		break;
 50
 51	/* write the word at location addr in the USER area */
 52	case PTRACE_POKEUSR:
 53		ret = poke_user(child, addr, data);
 54		break;
 55
 56	case PTRACE_SYSEMU:
 57	case PTRACE_SYSEMU_SINGLESTEP:
 58		ret = -EIO;
 59		break;
 60
 61#ifdef PTRACE_GETREGS
 62	case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 63		if (!access_ok(p, MAX_REG_OFFSET)) {
 64			ret = -EIO;
 65			break;
 66		}
 67		for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
 68			__put_user(getreg(child, i), p);
 69			p++;
 70		}
 71		ret = 0;
 72		break;
 73	}
 74#endif
 75#ifdef PTRACE_SETREGS
 76	case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 77		unsigned long tmp = 0;
 78		if (!access_ok(p, MAX_REG_OFFSET)) {
 79			ret = -EIO;
 80			break;
 81		}
 82		for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
 83			__get_user(tmp, p);
 84			putreg(child, i, tmp);
 85			p++;
 86		}
 87		ret = 0;
 88		break;
 89	}
 90#endif
 91	case PTRACE_GET_THREAD_AREA:
 92		ret = ptrace_get_thread_area(child, addr, vp);
 93		break;
 94
 95	case PTRACE_SET_THREAD_AREA:
 96		ret = ptrace_set_thread_area(child, addr, vp);
 97		break;
 98
 99	default:
100		ret = ptrace_request(child, request, addr, data);
101		if (ret == -EIO)
102			ret = subarch_ptrace(child, request, addr, data);
103		break;
104	}
105
106	return ret;
107}
108
109static void send_sigtrap(struct uml_pt_regs *regs, int error_code)
110{
111	/* Send us the fake SIGTRAP */
112	force_sig_fault(SIGTRAP, TRAP_BRKPT,
113			/* User-mode eip? */
114			UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL);
115}
116
117/*
118 * XXX Check TIF_SINGLESTEP for singlestepping check and
119 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
120 */
121int syscall_trace_enter(struct pt_regs *regs)
122{
123	audit_syscall_entry(UPT_SYSCALL_NR(&regs->regs),
124			    UPT_SYSCALL_ARG1(&regs->regs),
125			    UPT_SYSCALL_ARG2(&regs->regs),
126			    UPT_SYSCALL_ARG3(&regs->regs),
127			    UPT_SYSCALL_ARG4(&regs->regs));
128
129	if (!test_thread_flag(TIF_SYSCALL_TRACE))
130		return 0;
131
132	return ptrace_report_syscall_entry(regs);
133}
134
135void syscall_trace_leave(struct pt_regs *regs)
136{
137	int ptraced = current->ptrace;
138
139	audit_syscall_exit(regs);
140
141	/* Fake a debug trap */
142	if (test_thread_flag(TIF_SINGLESTEP))
143		send_sigtrap(&regs->regs, 0);
144
145	if (!test_thread_flag(TIF_SYSCALL_TRACE))
146		return;
147
148	ptrace_report_syscall_exit(regs, 0);
149	/* force do_signal() --> is_syscall() */
150	if (ptraced & PT_PTRACED)
151		set_thread_flag(TIF_SIGPENDING);
152}