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 | */ |
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 | */ |
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 | |
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: &attr); |
73 | } |
74 | |
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: &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: &attr, triggered: ptrace_triggered, |
90 | NULL, tsk); |
91 | if (IS_ERR(ptr: bp)) |
92 | return PTR_ERR(ptr: 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: &attr); |
103 | if (unlikely(err)) |
104 | return err; |
105 | } |
106 | |
107 | return 0; |
108 | } |
109 | |
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(tsk: child, TIF_SINGLESTEP); |
115 | |
116 | set_single_step(tsk: child, addr: pc); |
117 | } |
118 | |
119 | void user_disable_single_step(struct task_struct *child) |
120 | { |
121 | clear_tsk_thread_flag(tsk: 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 | */ |
129 | void ptrace_disable(struct task_struct *child) |
130 | { |
131 | user_disable_single_step(child); |
132 | } |
133 | |
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(s: &to, v: regs, size: sizeof(struct pt_regs)); |
141 | } |
142 | |
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: &pos, count: &count, kbuf: &kbuf, ubuf: &ubuf, |
152 | data: regs->regs, |
153 | start_pos: 0, end_pos: 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: &pos, count: &count, kbuf: &kbuf, ubuf: &ubuf, |
161 | start_pos: sizeof(struct pt_regs), end_pos: -1); |
162 | |
163 | return ret; |
164 | } |
165 | |
166 | #ifdef CONFIG_SH_FPU |
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 | |
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 | |
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 |
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 | |
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 | |
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 | |
333 | const struct user_regset_view *task_user_regset_view(struct task_struct *task) |
334 | { |
335 | return &user_sh_native_view; |
336 | } |
337 | |
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(task: child, offset: 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(task: child, offset: 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(target: child, view: &user_sh_native_view, |
415 | setno: REGSET_GENERAL, |
416 | offset: 0, size: sizeof(struct pt_regs), |
417 | data: datap); |
418 | case PTRACE_SETREGS: |
419 | return copy_regset_from_user(target: child, view: &user_sh_native_view, |
420 | setno: REGSET_GENERAL, |
421 | offset: 0, size: sizeof(struct pt_regs), |
422 | data: 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 | |
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, id: regs->regs[0]); |
468 | |
469 | audit_syscall_entry(major: regs->regs[3], a0: regs->regs[4], a1: regs->regs[5], |
470 | a2: regs->regs[6], a3: regs->regs[7]); |
471 | |
472 | return 0; |
473 | } |
474 | |
475 | asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) |
476 | { |
477 | int step; |
478 | |
479 | audit_syscall_exit(pt_regs: regs); |
480 | |
481 | if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT))) |
482 | trace_sys_exit(regs, ret: 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 | |