GNU Linux-libre 6.1.91-gnu
[releases.git] / arch / um / kernel / ptrace.c
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         child->thread.singlestep_syscall = 0;
16
17 #ifdef SUBARCH_SET_SINGLESTEPPING
18         SUBARCH_SET_SINGLESTEPPING(child, 1);
19 #endif
20 }
21
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  */
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
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
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  */
126 int syscall_trace_enter(struct pt_regs *regs)
127 {
128         audit_syscall_entry(UPT_SYSCALL_NR(&regs->regs),
129                             UPT_SYSCALL_ARG1(&regs->regs),
130                             UPT_SYSCALL_ARG2(&regs->regs),
131                             UPT_SYSCALL_ARG3(&regs->regs),
132                             UPT_SYSCALL_ARG4(&regs->regs));
133
134         if (!test_thread_flag(TIF_SYSCALL_TRACE))
135                 return 0;
136
137         return ptrace_report_syscall_entry(regs);
138 }
139
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(&regs->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 }