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2b438454 MS |
1 | /* |
2 | * `ptrace' system call | |
3 | * | |
4 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> | |
5 | * Copyright (C) 2007-2009 PetaLogix | |
6 | * Copyright (C) 2004-2007 John Williams <john.williams@petalogix.com> | |
7 | * | |
8 | * derived from arch/v850/kernel/ptrace.c | |
9 | * | |
10 | * Copyright (C) 2002,03 NEC Electronics Corporation | |
11 | * Copyright (C) 2002,03 Miles Bader <miles@gnu.org> | |
12 | * | |
13 | * Derived from arch/mips/kernel/ptrace.c: | |
14 | * | |
15 | * Copyright (C) 1992 Ross Biro | |
16 | * Copyright (C) Linus Torvalds | |
17 | * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle | |
18 | * Copyright (C) 1996 David S. Miller | |
19 | * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com | |
20 | * Copyright (C) 1999 MIPS Technologies, Inc. | |
21 | * | |
22 | * This file is subject to the terms and conditions of the GNU General | |
23 | * Public License. See the file COPYING in the main directory of this | |
24 | * archive for more details. | |
25 | */ | |
26 | ||
27 | #include <linux/kernel.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/sched.h> | |
2b438454 MS |
30 | #include <linux/ptrace.h> |
31 | #include <linux/signal.h> | |
23575483 MS |
32 | #include <linux/elf.h> |
33 | #include <linux/audit.h> | |
34 | #include <linux/seccomp.h> | |
35 | #include <linux/tracehook.h> | |
2b438454 MS |
36 | |
37 | #include <linux/errno.h> | |
2b438454 MS |
38 | #include <asm/processor.h> |
39 | #include <linux/uaccess.h> | |
40 | #include <asm/asm-offsets.h> | |
41 | ||
42 | /* Returns the address where the register at REG_OFFS in P is stashed away. */ | |
43 | static microblaze_reg_t *reg_save_addr(unsigned reg_offs, | |
44 | struct task_struct *t) | |
45 | { | |
46 | struct pt_regs *regs; | |
47 | ||
48 | /* | |
49 | * Three basic cases: | |
50 | * | |
51 | * (1) A register normally saved before calling the scheduler, is | |
52 | * available in the kernel entry pt_regs structure at the top | |
53 | * of the kernel stack. The kernel trap/irq exit path takes | |
54 | * care to save/restore almost all registers for ptrace'd | |
55 | * processes. | |
56 | * | |
57 | * (2) A call-clobbered register, where the process P entered the | |
58 | * kernel via [syscall] trap, is not stored anywhere; that's | |
59 | * OK, because such registers are not expected to be preserved | |
60 | * when the trap returns anyway (so we don't actually bother to | |
61 | * test for this case). | |
62 | * | |
63 | * (3) A few registers not used at all by the kernel, and so | |
64 | * normally never saved except by context-switches, are in the | |
65 | * context switch state. | |
66 | */ | |
67 | ||
68 | /* Register saved during kernel entry (or not available). */ | |
69 | regs = task_pt_regs(t); | |
70 | ||
71 | return (microblaze_reg_t *)((char *)regs + reg_offs); | |
72 | } | |
73 | ||
74 | long arch_ptrace(struct task_struct *child, long request, long addr, long data) | |
75 | { | |
76 | int rval; | |
77 | unsigned long val = 0; | |
78 | unsigned long copied; | |
79 | ||
80 | switch (request) { | |
81 | case PTRACE_PEEKTEXT: /* read word at location addr. */ | |
82 | case PTRACE_PEEKDATA: | |
83 | pr_debug("PEEKTEXT/PEEKDATA at %08lX\n", addr); | |
84 | copied = access_process_vm(child, addr, &val, sizeof(val), 0); | |
85 | rval = -EIO; | |
86 | if (copied != sizeof(val)) | |
87 | break; | |
88 | rval = put_user(val, (unsigned long *)data); | |
89 | break; | |
90 | ||
91 | case PTRACE_POKETEXT: /* write the word at location addr. */ | |
92 | case PTRACE_POKEDATA: | |
93 | pr_debug("POKETEXT/POKEDATA to %08lX\n", addr); | |
94 | rval = 0; | |
95 | if (access_process_vm(child, addr, &data, sizeof(data), 1) | |
96 | == sizeof(data)) | |
97 | break; | |
98 | rval = -EIO; | |
99 | break; | |
100 | ||
101 | /* Read/write the word at location ADDR in the registers. */ | |
102 | case PTRACE_PEEKUSR: | |
103 | case PTRACE_POKEUSR: | |
104 | pr_debug("PEEKUSR/POKEUSR : 0x%08lx\n", addr); | |
105 | rval = 0; | |
106 | if (addr >= PT_SIZE && request == PTRACE_PEEKUSR) { | |
107 | /* | |
108 | * Special requests that don't actually correspond | |
109 | * to offsets in struct pt_regs. | |
110 | */ | |
111 | if (addr == PT_TEXT_ADDR) { | |
112 | val = child->mm->start_code; | |
113 | } else if (addr == PT_DATA_ADDR) { | |
114 | val = child->mm->start_data; | |
115 | } else if (addr == PT_TEXT_LEN) { | |
116 | val = child->mm->end_code | |
117 | - child->mm->start_code; | |
118 | } else { | |
119 | rval = -EIO; | |
120 | } | |
121 | } else if (addr >= 0 && addr < PT_SIZE && (addr & 0x3) == 0) { | |
122 | microblaze_reg_t *reg_addr = reg_save_addr(addr, child); | |
123 | if (request == PTRACE_PEEKUSR) | |
124 | val = *reg_addr; | |
125 | else | |
126 | *reg_addr = data; | |
127 | } else | |
128 | rval = -EIO; | |
129 | ||
130 | if (rval == 0 && request == PTRACE_PEEKUSR) | |
131 | rval = put_user(val, (unsigned long *)data); | |
132 | break; | |
133 | /* Continue and stop at next (return from) syscall */ | |
134 | case PTRACE_SYSCALL: | |
135 | pr_debug("PTRACE_SYSCALL\n"); | |
136 | case PTRACE_SINGLESTEP: | |
137 | pr_debug("PTRACE_SINGLESTEP\n"); | |
138 | /* Restart after a signal. */ | |
139 | case PTRACE_CONT: | |
140 | pr_debug("PTRACE_CONT\n"); | |
141 | rval = -EIO; | |
142 | if (!valid_signal(data)) | |
143 | break; | |
144 | ||
145 | if (request == PTRACE_SYSCALL) | |
146 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
147 | else | |
148 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); | |
149 | ||
150 | child->exit_code = data; | |
151 | pr_debug("wakeup_process\n"); | |
152 | wake_up_process(child); | |
153 | rval = 0; | |
154 | break; | |
155 | ||
156 | /* | |
157 | * make the child exit. Best I can do is send it a sigkill. | |
158 | * perhaps it should be put in the status that it wants to | |
159 | * exit. | |
160 | */ | |
161 | case PTRACE_KILL: | |
162 | pr_debug("PTRACE_KILL\n"); | |
163 | rval = 0; | |
164 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ | |
165 | break; | |
166 | child->exit_code = SIGKILL; | |
167 | wake_up_process(child); | |
168 | break; | |
169 | ||
170 | case PTRACE_DETACH: /* detach a process that was attached. */ | |
171 | pr_debug("PTRACE_DETACH\n"); | |
172 | rval = ptrace_detach(child, data); | |
173 | break; | |
174 | default: | |
175 | /* rval = ptrace_request(child, request, addr, data); noMMU */ | |
176 | rval = -EIO; | |
177 | } | |
178 | return rval; | |
179 | } | |
180 | ||
23575483 MS |
181 | asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) |
182 | { | |
183 | long ret = 0; | |
184 | ||
185 | secure_computing(regs->r12); | |
186 | ||
187 | if (test_thread_flag(TIF_SYSCALL_TRACE) && | |
188 | tracehook_report_syscall_entry(regs)) | |
189 | /* | |
190 | * Tracing decided this syscall should not happen. | |
191 | * We'll return a bogus call number to get an ENOSYS | |
192 | * error, but leave the original number in regs->regs[0]. | |
193 | */ | |
194 | ret = -1L; | |
195 | ||
196 | if (unlikely(current->audit_context)) | |
197 | audit_syscall_entry(EM_XILINX_MICROBLAZE, regs->r12, | |
198 | regs->r5, regs->r6, | |
199 | regs->r7, regs->r8); | |
200 | ||
201 | return ret ?: regs->r12; | |
202 | } | |
203 | ||
204 | asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) | |
205 | { | |
206 | int step; | |
207 | ||
208 | if (unlikely(current->audit_context)) | |
209 | audit_syscall_exit(AUDITSC_RESULT(regs->r3), regs->r3); | |
210 | ||
211 | step = test_thread_flag(TIF_SINGLESTEP); | |
212 | if (step || test_thread_flag(TIF_SYSCALL_TRACE)) | |
213 | tracehook_report_syscall_exit(regs, step); | |
214 | } | |
215 | ||
216 | #if 0 | |
217 | static asmlinkage void syscall_trace(void) | |
218 | { | |
219 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) | |
220 | return; | |
221 | if (!(current->ptrace & PT_PTRACED)) | |
222 | return; | |
223 | /* The 0x80 provides a way for the tracing parent to distinguish | |
224 | between a syscall stop and SIGTRAP delivery */ | |
225 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) | |
226 | ? 0x80 : 0)); | |
227 | /* | |
228 | * this isn't the same as continuing with a signal, but it will do | |
229 | * for normal use. strace only continues with a signal if the | |
230 | * stopping signal is not SIGTRAP. -brl | |
231 | */ | |
232 | if (current->exit_code) { | |
233 | send_sig(current->exit_code, current, 1); | |
234 | current->exit_code = 0; | |
235 | } | |
236 | } | |
237 | #endif | |
238 | ||
2b438454 MS |
239 | void ptrace_disable(struct task_struct *child) |
240 | { | |
241 | /* nothing to do */ | |
242 | } |