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
12 void 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
21 void 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 */
33 void ptrace_disable(struct task_struct *child)
34 {
35 user_disable_single_step(child);
36 }
37
38 long 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
109 static 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 */
121 int syscall_trace_enter(struct pt_regs *regs)
122 {
123 audit_syscall_entry(UPT_SYSCALL_NR(®s->regs),
124 UPT_SYSCALL_ARG1(®s->regs),
125 UPT_SYSCALL_ARG2(®s->regs),
126 UPT_SYSCALL_ARG3(®s->regs),
127 UPT_SYSCALL_ARG4(®s->regs));
128
129 if (!test_thread_flag(TIF_SYSCALL_TRACE))
130 return 0;
131
132 return ptrace_report_syscall_entry(regs);
133 }
134
135 void 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(®s->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 }
153
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