1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * SuperH process tracing
4 *
5 * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
6 * Copyright (C) 2002 - 2009 Paul Mundt
7 *
8 * Audit support by Yuichi Nakamura <ynakam@hitachisoft.jp>
9 */
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <linux/sched/task_stack.h>
13 #include <linux/mm.h>
14 #include <linux/smp.h>
15 #include <linux/errno.h>
16 #include <linux/ptrace.h>
17 #include <linux/user.h>
18 #include <linux/security.h>
19 #include <linux/signal.h>
20 #include <linux/io.h>
21 #include <linux/audit.h>
22 #include <linux/seccomp.h>
23 #include <linux/elf.h>
24 #include <linux/regset.h>
25 #include <linux/hw_breakpoint.h>
26 #include <linux/uaccess.h>
27 #include <asm/processor.h>
28 #include <asm/mmu_context.h>
29 #include <asm/syscalls.h>
30 #include <asm/fpu.h>
31
32 #define CREATE_TRACE_POINTS
33 #include <trace/events/syscalls.h>
34
35 /*
36 * This routine will get a word off of the process kernel stack.
37 */
get_stack_long(struct task_struct * task,int offset)38 static inline int get_stack_long(struct task_struct *task, int offset)
39 {
40 unsigned char *stack;
41
42 stack = (unsigned char *)task_pt_regs(task);
43 stack += offset;
44 return (*((int *)stack));
45 }
46
47 /*
48 * This routine will put a word on the process kernel stack.
49 */
put_stack_long(struct task_struct * task,int offset,unsigned long data)50 static inline int put_stack_long(struct task_struct *task, int offset,
51 unsigned long data)
52 {
53 unsigned char *stack;
54
55 stack = (unsigned char *)task_pt_regs(task);
56 stack += offset;
57 *(unsigned long *) stack = data;
58 return 0;
59 }
60
ptrace_triggered(struct perf_event * bp,struct perf_sample_data * data,struct pt_regs * regs)61 void ptrace_triggered(struct perf_event *bp,
62 struct perf_sample_data *data, struct pt_regs *regs)
63 {
64 struct perf_event_attr attr;
65
66 /*
67 * Disable the breakpoint request here since ptrace has defined a
68 * one-shot behaviour for breakpoint exceptions.
69 */
70 attr = bp->attr;
71 attr.disabled = true;
72 modify_user_hw_breakpoint(bp, &attr);
73 }
74
set_single_step(struct task_struct * tsk,unsigned long addr)75 static int set_single_step(struct task_struct *tsk, unsigned long addr)
76 {
77 struct thread_struct *thread = &tsk->thread;
78 struct perf_event *bp;
79 struct perf_event_attr attr;
80
81 bp = thread->ptrace_bps[0];
82 if (!bp) {
83 ptrace_breakpoint_init(&attr);
84
85 attr.bp_addr = addr;
86 attr.bp_len = HW_BREAKPOINT_LEN_2;
87 attr.bp_type = HW_BREAKPOINT_R;
88
89 bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
90 NULL, tsk);
91 if (IS_ERR(bp))
92 return PTR_ERR(bp);
93
94 thread->ptrace_bps[0] = bp;
95 } else {
96 int err;
97
98 attr = bp->attr;
99 attr.bp_addr = addr;
100 /* reenable breakpoint */
101 attr.disabled = false;
102 err = modify_user_hw_breakpoint(bp, &attr);
103 if (unlikely(err))
104 return err;
105 }
106
107 return 0;
108 }
109
user_enable_single_step(struct task_struct * child)110 void user_enable_single_step(struct task_struct *child)
111 {
112 unsigned long pc = get_stack_long(child, offsetof(struct pt_regs, pc));
113
114 set_tsk_thread_flag(child, TIF_SINGLESTEP);
115
116 set_single_step(child, pc);
117 }
118
user_disable_single_step(struct task_struct * child)119 void user_disable_single_step(struct task_struct *child)
120 {
121 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
122 }
123
124 /*
125 * Called by kernel/ptrace.c when detaching..
126 *
127 * Make sure single step bits etc are not set.
128 */
ptrace_disable(struct task_struct * child)129 void ptrace_disable(struct task_struct *child)
130 {
131 user_disable_single_step(child);
132 }
133
genregs_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)134 static int genregs_get(struct task_struct *target,
135 const struct user_regset *regset,
136 struct membuf to)
137 {
138 const struct pt_regs *regs = task_pt_regs(target);
139
140 return membuf_write(&to, regs, sizeof(struct pt_regs));
141 }
142
genregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)143 static int genregs_set(struct task_struct *target,
144 const struct user_regset *regset,
145 unsigned int pos, unsigned int count,
146 const void *kbuf, const void __user *ubuf)
147 {
148 struct pt_regs *regs = task_pt_regs(target);
149 int ret;
150
151 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
152 regs->regs,
153 0, 16 * sizeof(unsigned long));
154 if (!ret && count > 0)
155 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
156 ®s->pc,
157 offsetof(struct pt_regs, pc),
158 sizeof(struct pt_regs));
159 if (!ret)
160 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
161 sizeof(struct pt_regs), -1);
162
163 return ret;
164 }
165
166 #ifdef CONFIG_SH_FPU
fpregs_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)167 static int fpregs_get(struct task_struct *target,
168 const struct user_regset *regset,
169 struct membuf to)
170 {
171 int ret;
172
173 ret = init_fpu(target);
174 if (ret)
175 return ret;
176
177 return membuf_write(&to, target->thread.xstate,
178 sizeof(struct user_fpu_struct));
179 }
180
fpregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)181 static int fpregs_set(struct task_struct *target,
182 const struct user_regset *regset,
183 unsigned int pos, unsigned int count,
184 const void *kbuf, const void __user *ubuf)
185 {
186 int ret;
187
188 ret = init_fpu(target);
189 if (ret)
190 return ret;
191
192 set_stopped_child_used_math(target);
193
194 if ((boot_cpu_data.flags & CPU_HAS_FPU))
195 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
196 &target->thread.xstate->hardfpu, 0, -1);
197
198 return user_regset_copyin(&pos, &count, &kbuf, &ubuf,
199 &target->thread.xstate->softfpu, 0, -1);
200 }
201
fpregs_active(struct task_struct * target,const struct user_regset * regset)202 static int fpregs_active(struct task_struct *target,
203 const struct user_regset *regset)
204 {
205 return tsk_used_math(target) ? regset->n : 0;
206 }
207 #endif
208
209 #ifdef CONFIG_SH_DSP
dspregs_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)210 static int dspregs_get(struct task_struct *target,
211 const struct user_regset *regset,
212 struct membuf to)
213 {
214 const struct pt_dspregs *regs =
215 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
216
217 return membuf_write(&to, regs, sizeof(struct pt_dspregs));
218 }
219
dspregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)220 static int dspregs_set(struct task_struct *target,
221 const struct user_regset *regset,
222 unsigned int pos, unsigned int count,
223 const void *kbuf, const void __user *ubuf)
224 {
225 struct pt_dspregs *regs =
226 (struct pt_dspregs *)&target->thread.dsp_status.dsp_regs;
227 int ret;
228
229 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, regs,
230 0, sizeof(struct pt_dspregs));
231 if (!ret)
232 user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
233 sizeof(struct pt_dspregs), -1);
234
235 return ret;
236 }
237
dspregs_active(struct task_struct * target,const struct user_regset * regset)238 static int dspregs_active(struct task_struct *target,
239 const struct user_regset *regset)
240 {
241 struct pt_regs *regs = task_pt_regs(target);
242
243 return regs->sr & SR_DSP ? regset->n : 0;
244 }
245 #endif
246
247 const struct pt_regs_offset regoffset_table[] = {
248 REGS_OFFSET_NAME(0),
249 REGS_OFFSET_NAME(1),
250 REGS_OFFSET_NAME(2),
251 REGS_OFFSET_NAME(3),
252 REGS_OFFSET_NAME(4),
253 REGS_OFFSET_NAME(5),
254 REGS_OFFSET_NAME(6),
255 REGS_OFFSET_NAME(7),
256 REGS_OFFSET_NAME(8),
257 REGS_OFFSET_NAME(9),
258 REGS_OFFSET_NAME(10),
259 REGS_OFFSET_NAME(11),
260 REGS_OFFSET_NAME(12),
261 REGS_OFFSET_NAME(13),
262 REGS_OFFSET_NAME(14),
263 REGS_OFFSET_NAME(15),
264 REG_OFFSET_NAME(pc),
265 REG_OFFSET_NAME(pr),
266 REG_OFFSET_NAME(sr),
267 REG_OFFSET_NAME(gbr),
268 REG_OFFSET_NAME(mach),
269 REG_OFFSET_NAME(macl),
270 REG_OFFSET_NAME(tra),
271 REG_OFFSET_END,
272 };
273
274 /*
275 * These are our native regset flavours.
276 */
277 enum sh_regset {
278 REGSET_GENERAL,
279 #ifdef CONFIG_SH_FPU
280 REGSET_FPU,
281 #endif
282 #ifdef CONFIG_SH_DSP
283 REGSET_DSP,
284 #endif
285 };
286
287 static const struct user_regset sh_regsets[] = {
288 /*
289 * Format is:
290 * R0 --> R15
291 * PC, PR, SR, GBR, MACH, MACL, TRA
292 */
293 [REGSET_GENERAL] = {
294 .core_note_type = NT_PRSTATUS,
295 .n = ELF_NGREG,
296 .size = sizeof(long),
297 .align = sizeof(long),
298 .regset_get = genregs_get,
299 .set = genregs_set,
300 },
301
302 #ifdef CONFIG_SH_FPU
303 [REGSET_FPU] = {
304 .core_note_type = NT_PRFPREG,
305 .n = sizeof(struct user_fpu_struct) / sizeof(long),
306 .size = sizeof(long),
307 .align = sizeof(long),
308 .regset_get = fpregs_get,
309 .set = fpregs_set,
310 .active = fpregs_active,
311 },
312 #endif
313
314 #ifdef CONFIG_SH_DSP
315 [REGSET_DSP] = {
316 .n = sizeof(struct pt_dspregs) / sizeof(long),
317 .size = sizeof(long),
318 .align = sizeof(long),
319 .regset_get = dspregs_get,
320 .set = dspregs_set,
321 .active = dspregs_active,
322 },
323 #endif
324 };
325
326 static const struct user_regset_view user_sh_native_view = {
327 .name = "sh",
328 .e_machine = EM_SH,
329 .regsets = sh_regsets,
330 .n = ARRAY_SIZE(sh_regsets),
331 };
332
task_user_regset_view(struct task_struct * task)333 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
334 {
335 return &user_sh_native_view;
336 }
337
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)338 long arch_ptrace(struct task_struct *child, long request,
339 unsigned long addr, unsigned long data)
340 {
341 unsigned long __user *datap = (unsigned long __user *)data;
342 int ret;
343
344 switch (request) {
345 /* read the word at location addr in the USER area. */
346 case PTRACE_PEEKUSR: {
347 unsigned long tmp;
348
349 ret = -EIO;
350 if ((addr & 3) || addr < 0 ||
351 addr > sizeof(struct user) - 3)
352 break;
353
354 if (addr < sizeof(struct pt_regs))
355 tmp = get_stack_long(child, addr);
356 else if (addr >= offsetof(struct user, fpu) &&
357 addr < offsetof(struct user, u_fpvalid)) {
358 if (!tsk_used_math(child)) {
359 if (addr == offsetof(struct user, fpu.fpscr))
360 tmp = FPSCR_INIT;
361 else
362 tmp = 0;
363 } else {
364 unsigned long index;
365 ret = init_fpu(child);
366 if (ret)
367 break;
368 index = addr - offsetof(struct user, fpu);
369 tmp = ((unsigned long *)child->thread.xstate)
370 [index >> 2];
371 }
372 } else if (addr == offsetof(struct user, u_fpvalid))
373 tmp = !!tsk_used_math(child);
374 else if (addr == PT_TEXT_ADDR)
375 tmp = child->mm->start_code;
376 else if (addr == PT_DATA_ADDR)
377 tmp = child->mm->start_data;
378 else if (addr == PT_TEXT_END_ADDR)
379 tmp = child->mm->end_code;
380 else if (addr == PT_TEXT_LEN)
381 tmp = child->mm->end_code - child->mm->start_code;
382 else
383 tmp = 0;
384 ret = put_user(tmp, datap);
385 break;
386 }
387
388 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
389 ret = -EIO;
390 if ((addr & 3) || addr < 0 ||
391 addr > sizeof(struct user) - 3)
392 break;
393
394 if (addr < sizeof(struct pt_regs))
395 ret = put_stack_long(child, addr, data);
396 else if (addr >= offsetof(struct user, fpu) &&
397 addr < offsetof(struct user, u_fpvalid)) {
398 unsigned long index;
399 ret = init_fpu(child);
400 if (ret)
401 break;
402 index = addr - offsetof(struct user, fpu);
403 set_stopped_child_used_math(child);
404 ((unsigned long *)child->thread.xstate)
405 [index >> 2] = data;
406 ret = 0;
407 } else if (addr == offsetof(struct user, u_fpvalid)) {
408 conditional_stopped_child_used_math(data, child);
409 ret = 0;
410 }
411 break;
412
413 case PTRACE_GETREGS:
414 return copy_regset_to_user(child, &user_sh_native_view,
415 REGSET_GENERAL,
416 0, sizeof(struct pt_regs),
417 datap);
418 case PTRACE_SETREGS:
419 return copy_regset_from_user(child, &user_sh_native_view,
420 REGSET_GENERAL,
421 0, sizeof(struct pt_regs),
422 datap);
423 #ifdef CONFIG_SH_FPU
424 case PTRACE_GETFPREGS:
425 return copy_regset_to_user(child, &user_sh_native_view,
426 REGSET_FPU,
427 0, sizeof(struct user_fpu_struct),
428 datap);
429 case PTRACE_SETFPREGS:
430 return copy_regset_from_user(child, &user_sh_native_view,
431 REGSET_FPU,
432 0, sizeof(struct user_fpu_struct),
433 datap);
434 #endif
435 #ifdef CONFIG_SH_DSP
436 case PTRACE_GETDSPREGS:
437 return copy_regset_to_user(child, &user_sh_native_view,
438 REGSET_DSP,
439 0, sizeof(struct pt_dspregs),
440 datap);
441 case PTRACE_SETDSPREGS:
442 return copy_regset_from_user(child, &user_sh_native_view,
443 REGSET_DSP,
444 0, sizeof(struct pt_dspregs),
445 datap);
446 #endif
447 default:
448 ret = ptrace_request(child, request, addr, data);
449 break;
450 }
451
452 return ret;
453 }
454
do_syscall_trace_enter(struct pt_regs * regs)455 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
456 {
457 if (test_thread_flag(TIF_SYSCALL_TRACE) &&
458 ptrace_report_syscall_entry(regs)) {
459 regs->regs[0] = -ENOSYS;
460 return -1;
461 }
462
463 if (secure_computing() == -1)
464 return -1;
465
466 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
467 trace_sys_enter(regs, regs->regs[0]);
468
469 audit_syscall_entry(regs->regs[3], regs->regs[4], regs->regs[5],
470 regs->regs[6], regs->regs[7]);
471
472 return 0;
473 }
474
do_syscall_trace_leave(struct pt_regs * regs)475 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
476 {
477 int step;
478
479 audit_syscall_exit(regs);
480
481 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
482 trace_sys_exit(regs, regs->regs[0]);
483
484 step = test_thread_flag(TIF_SINGLESTEP);
485 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
486 ptrace_report_syscall_exit(regs, step);
487 }
488