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
user_enable_single_step(struct task_struct * child)12 void user_enable_single_step(struct task_struct *child)
13 {
14 set_tsk_thread_flag(child, TIF_SINGLESTEP);
15 child->thread.singlestep_syscall = 0;
16
17 #ifdef SUBARCH_SET_SINGLESTEPPING
18 SUBARCH_SET_SINGLESTEPPING(child, 1);
19 #endif
20 }
21
user_disable_single_step(struct task_struct * child)22 void user_disable_single_step(struct task_struct *child)
23 {
24 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
25 child->thread.singlestep_syscall = 0;
26
27 #ifdef SUBARCH_SET_SINGLESTEPPING
28 SUBARCH_SET_SINGLESTEPPING(child, 0);
29 #endif
30 }
31
32 /*
33 * Called by kernel/ptrace.c when detaching..
34 */
ptrace_disable(struct task_struct * child)35 void ptrace_disable(struct task_struct *child)
36 {
37 user_disable_single_step(child);
38 }
39
40 extern int peek_user(struct task_struct * child, long addr, long data);
41 extern int poke_user(struct task_struct * child, long addr, long data);
42
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)43 long arch_ptrace(struct task_struct *child, long request,
44 unsigned long addr, unsigned long data)
45 {
46 int i, ret;
47 unsigned long __user *p = (void __user *)data;
48 void __user *vp = p;
49
50 switch (request) {
51 /* read the word at location addr in the USER area. */
52 case PTRACE_PEEKUSR:
53 ret = peek_user(child, addr, data);
54 break;
55
56 /* write the word at location addr in the USER area */
57 case PTRACE_POKEUSR:
58 ret = poke_user(child, addr, data);
59 break;
60
61 case PTRACE_SYSEMU:
62 case PTRACE_SYSEMU_SINGLESTEP:
63 ret = -EIO;
64 break;
65
66 #ifdef PTRACE_GETREGS
67 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
68 if (!access_ok(p, MAX_REG_OFFSET)) {
69 ret = -EIO;
70 break;
71 }
72 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
73 __put_user(getreg(child, i), p);
74 p++;
75 }
76 ret = 0;
77 break;
78 }
79 #endif
80 #ifdef PTRACE_SETREGS
81 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
82 unsigned long tmp = 0;
83 if (!access_ok(p, MAX_REG_OFFSET)) {
84 ret = -EIO;
85 break;
86 }
87 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) {
88 __get_user(tmp, p);
89 putreg(child, i, tmp);
90 p++;
91 }
92 ret = 0;
93 break;
94 }
95 #endif
96 case PTRACE_GET_THREAD_AREA:
97 ret = ptrace_get_thread_area(child, addr, vp);
98 break;
99
100 case PTRACE_SET_THREAD_AREA:
101 ret = ptrace_set_thread_area(child, addr, vp);
102 break;
103
104 default:
105 ret = ptrace_request(child, request, addr, data);
106 if (ret == -EIO)
107 ret = subarch_ptrace(child, request, addr, data);
108 break;
109 }
110
111 return ret;
112 }
113
send_sigtrap(struct uml_pt_regs * regs,int error_code)114 static void send_sigtrap(struct uml_pt_regs *regs, int error_code)
115 {
116 /* Send us the fake SIGTRAP */
117 force_sig_fault(SIGTRAP, TRAP_BRKPT,
118 /* User-mode eip? */
119 UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL);
120 }
121
122 /*
123 * XXX Check TIF_SINGLESTEP for singlestepping check and
124 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check
125 */
syscall_trace_enter(struct pt_regs * regs)126 int syscall_trace_enter(struct pt_regs *regs)
127 {
128 audit_syscall_entry(UPT_SYSCALL_NR(®s->regs),
129 UPT_SYSCALL_ARG1(®s->regs),
130 UPT_SYSCALL_ARG2(®s->regs),
131 UPT_SYSCALL_ARG3(®s->regs),
132 UPT_SYSCALL_ARG4(®s->regs));
133
134 if (!test_thread_flag(TIF_SYSCALL_TRACE))
135 return 0;
136
137 return ptrace_report_syscall_entry(regs);
138 }
139
syscall_trace_leave(struct pt_regs * regs)140 void syscall_trace_leave(struct pt_regs *regs)
141 {
142 int ptraced = current->ptrace;
143
144 audit_syscall_exit(regs);
145
146 /* Fake a debug trap */
147 if (test_thread_flag(TIF_SINGLESTEP))
148 send_sigtrap(®s->regs, 0);
149
150 if (!test_thread_flag(TIF_SYSCALL_TRACE))
151 return;
152
153 ptrace_report_syscall_exit(regs, 0);
154 /* force do_signal() --> is_syscall() */
155 if (ptraced & PT_PTRACED)
156 set_thread_flag(TIF_SIGPENDING);
157 }
158