1 // SPDX-License-Identifier: GPL-2.0-only
2 /* By Ross Biro 1/23/92 */
3 /*
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
6 */
7
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/sched/task_stack.h>
11 #include <linux/mm.h>
12 #include <linux/smp.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/ptrace.h>
16 #include <linux/tracehook.h>
17 #include <linux/user.h>
18 #include <linux/elf.h>
19 #include <linux/security.h>
20 #include <linux/audit.h>
21 #include <linux/seccomp.h>
22 #include <linux/signal.h>
23 #include <linux/perf_event.h>
24 #include <linux/hw_breakpoint.h>
25 #include <linux/rcupdate.h>
26 #include <linux/export.h>
27 #include <linux/context_tracking.h>
28 #include <linux/nospec.h>
29
30 #include <linux/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/processor.h>
33 #include <asm/fpu/internal.h>
34 #include <asm/fpu/signal.h>
35 #include <asm/fpu/regset.h>
36 #include <asm/debugreg.h>
37 #include <asm/ldt.h>
38 #include <asm/desc.h>
39 #include <asm/prctl.h>
40 #include <asm/proto.h>
41 #include <asm/hw_breakpoint.h>
42 #include <asm/traps.h>
43 #include <asm/syscall.h>
44 #include <asm/fsgsbase.h>
45
46 #include "tls.h"
47
48 enum x86_regset {
49 REGSET_GENERAL,
50 REGSET_FP,
51 REGSET_XFP,
52 REGSET_IOPERM64 = REGSET_XFP,
53 REGSET_XSTATE,
54 REGSET_TLS,
55 REGSET_IOPERM32,
56 };
57
58 struct pt_regs_offset {
59 const char *name;
60 int offset;
61 };
62
63 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
64 #define REG_OFFSET_END {.name = NULL, .offset = 0}
65
66 static const struct pt_regs_offset regoffset_table[] = {
67 #ifdef CONFIG_X86_64
68 REG_OFFSET_NAME(r15),
69 REG_OFFSET_NAME(r14),
70 REG_OFFSET_NAME(r13),
71 REG_OFFSET_NAME(r12),
72 REG_OFFSET_NAME(r11),
73 REG_OFFSET_NAME(r10),
74 REG_OFFSET_NAME(r9),
75 REG_OFFSET_NAME(r8),
76 #endif
77 REG_OFFSET_NAME(bx),
78 REG_OFFSET_NAME(cx),
79 REG_OFFSET_NAME(dx),
80 REG_OFFSET_NAME(si),
81 REG_OFFSET_NAME(di),
82 REG_OFFSET_NAME(bp),
83 REG_OFFSET_NAME(ax),
84 #ifdef CONFIG_X86_32
85 REG_OFFSET_NAME(ds),
86 REG_OFFSET_NAME(es),
87 REG_OFFSET_NAME(fs),
88 REG_OFFSET_NAME(gs),
89 #endif
90 REG_OFFSET_NAME(orig_ax),
91 REG_OFFSET_NAME(ip),
92 REG_OFFSET_NAME(cs),
93 REG_OFFSET_NAME(flags),
94 REG_OFFSET_NAME(sp),
95 REG_OFFSET_NAME(ss),
96 REG_OFFSET_END,
97 };
98
99 /**
100 * regs_query_register_offset() - query register offset from its name
101 * @name: the name of a register
102 *
103 * regs_query_register_offset() returns the offset of a register in struct
104 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
105 */
regs_query_register_offset(const char * name)106 int regs_query_register_offset(const char *name)
107 {
108 const struct pt_regs_offset *roff;
109 for (roff = regoffset_table; roff->name != NULL; roff++)
110 if (!strcmp(roff->name, name))
111 return roff->offset;
112 return -EINVAL;
113 }
114
115 /**
116 * regs_query_register_name() - query register name from its offset
117 * @offset: the offset of a register in struct pt_regs.
118 *
119 * regs_query_register_name() returns the name of a register from its
120 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
121 */
regs_query_register_name(unsigned int offset)122 const char *regs_query_register_name(unsigned int offset)
123 {
124 const struct pt_regs_offset *roff;
125 for (roff = regoffset_table; roff->name != NULL; roff++)
126 if (roff->offset == offset)
127 return roff->name;
128 return NULL;
129 }
130
131 /*
132 * does not yet catch signals sent when the child dies.
133 * in exit.c or in signal.c.
134 */
135
136 /*
137 * Determines which flags the user has access to [1 = access, 0 = no access].
138 */
139 #define FLAG_MASK_32 ((unsigned long) \
140 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
141 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
142 X86_EFLAGS_SF | X86_EFLAGS_TF | \
143 X86_EFLAGS_DF | X86_EFLAGS_OF | \
144 X86_EFLAGS_RF | X86_EFLAGS_AC))
145
146 /*
147 * Determines whether a value may be installed in a segment register.
148 */
invalid_selector(u16 value)149 static inline bool invalid_selector(u16 value)
150 {
151 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
152 }
153
154 #ifdef CONFIG_X86_32
155
156 #define FLAG_MASK FLAG_MASK_32
157
pt_regs_access(struct pt_regs * regs,unsigned long regno)158 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
159 {
160 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
161 return ®s->bx + (regno >> 2);
162 }
163
get_segment_reg(struct task_struct * task,unsigned long offset)164 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
165 {
166 /*
167 * Returning the value truncates it to 16 bits.
168 */
169 unsigned int retval;
170 if (offset != offsetof(struct user_regs_struct, gs))
171 retval = *pt_regs_access(task_pt_regs(task), offset);
172 else {
173 if (task == current)
174 retval = get_user_gs(task_pt_regs(task));
175 else
176 retval = task_user_gs(task);
177 }
178 return retval;
179 }
180
set_segment_reg(struct task_struct * task,unsigned long offset,u16 value)181 static int set_segment_reg(struct task_struct *task,
182 unsigned long offset, u16 value)
183 {
184 /*
185 * The value argument was already truncated to 16 bits.
186 */
187 if (invalid_selector(value))
188 return -EIO;
189
190 /*
191 * For %cs and %ss we cannot permit a null selector.
192 * We can permit a bogus selector as long as it has USER_RPL.
193 * Null selectors are fine for other segment registers, but
194 * we will never get back to user mode with invalid %cs or %ss
195 * and will take the trap in iret instead. Much code relies
196 * on user_mode() to distinguish a user trap frame (which can
197 * safely use invalid selectors) from a kernel trap frame.
198 */
199 switch (offset) {
200 case offsetof(struct user_regs_struct, cs):
201 case offsetof(struct user_regs_struct, ss):
202 if (unlikely(value == 0))
203 return -EIO;
204 /* Else, fall through */
205
206 default:
207 *pt_regs_access(task_pt_regs(task), offset) = value;
208 break;
209
210 case offsetof(struct user_regs_struct, gs):
211 if (task == current)
212 set_user_gs(task_pt_regs(task), value);
213 else
214 task_user_gs(task) = value;
215 }
216
217 return 0;
218 }
219
220 #else /* CONFIG_X86_64 */
221
222 #define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
223
pt_regs_access(struct pt_regs * regs,unsigned long offset)224 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
225 {
226 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
227 return ®s->r15 + (offset / sizeof(regs->r15));
228 }
229
get_segment_reg(struct task_struct * task,unsigned long offset)230 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
231 {
232 /*
233 * Returning the value truncates it to 16 bits.
234 */
235 unsigned int seg;
236
237 switch (offset) {
238 case offsetof(struct user_regs_struct, fs):
239 if (task == current) {
240 /* Older gas can't assemble movq %?s,%r?? */
241 asm("movl %%fs,%0" : "=r" (seg));
242 return seg;
243 }
244 return task->thread.fsindex;
245 case offsetof(struct user_regs_struct, gs):
246 if (task == current) {
247 asm("movl %%gs,%0" : "=r" (seg));
248 return seg;
249 }
250 return task->thread.gsindex;
251 case offsetof(struct user_regs_struct, ds):
252 if (task == current) {
253 asm("movl %%ds,%0" : "=r" (seg));
254 return seg;
255 }
256 return task->thread.ds;
257 case offsetof(struct user_regs_struct, es):
258 if (task == current) {
259 asm("movl %%es,%0" : "=r" (seg));
260 return seg;
261 }
262 return task->thread.es;
263
264 case offsetof(struct user_regs_struct, cs):
265 case offsetof(struct user_regs_struct, ss):
266 break;
267 }
268 return *pt_regs_access(task_pt_regs(task), offset);
269 }
270
set_segment_reg(struct task_struct * task,unsigned long offset,u16 value)271 static int set_segment_reg(struct task_struct *task,
272 unsigned long offset, u16 value)
273 {
274 /*
275 * The value argument was already truncated to 16 bits.
276 */
277 if (invalid_selector(value))
278 return -EIO;
279
280 switch (offset) {
281 case offsetof(struct user_regs_struct,fs):
282 task->thread.fsindex = value;
283 if (task == current)
284 loadsegment(fs, task->thread.fsindex);
285 break;
286 case offsetof(struct user_regs_struct,gs):
287 task->thread.gsindex = value;
288 if (task == current)
289 load_gs_index(task->thread.gsindex);
290 break;
291 case offsetof(struct user_regs_struct,ds):
292 task->thread.ds = value;
293 if (task == current)
294 loadsegment(ds, task->thread.ds);
295 break;
296 case offsetof(struct user_regs_struct,es):
297 task->thread.es = value;
298 if (task == current)
299 loadsegment(es, task->thread.es);
300 break;
301
302 /*
303 * Can't actually change these in 64-bit mode.
304 */
305 case offsetof(struct user_regs_struct,cs):
306 if (unlikely(value == 0))
307 return -EIO;
308 task_pt_regs(task)->cs = value;
309 break;
310 case offsetof(struct user_regs_struct,ss):
311 if (unlikely(value == 0))
312 return -EIO;
313 task_pt_regs(task)->ss = value;
314 break;
315 }
316
317 return 0;
318 }
319
320 #endif /* CONFIG_X86_32 */
321
get_flags(struct task_struct * task)322 static unsigned long get_flags(struct task_struct *task)
323 {
324 unsigned long retval = task_pt_regs(task)->flags;
325
326 /*
327 * If the debugger set TF, hide it from the readout.
328 */
329 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
330 retval &= ~X86_EFLAGS_TF;
331
332 return retval;
333 }
334
set_flags(struct task_struct * task,unsigned long value)335 static int set_flags(struct task_struct *task, unsigned long value)
336 {
337 struct pt_regs *regs = task_pt_regs(task);
338
339 /*
340 * If the user value contains TF, mark that
341 * it was not "us" (the debugger) that set it.
342 * If not, make sure it stays set if we had.
343 */
344 if (value & X86_EFLAGS_TF)
345 clear_tsk_thread_flag(task, TIF_FORCED_TF);
346 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
347 value |= X86_EFLAGS_TF;
348
349 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
350
351 return 0;
352 }
353
putreg(struct task_struct * child,unsigned long offset,unsigned long value)354 static int putreg(struct task_struct *child,
355 unsigned long offset, unsigned long value)
356 {
357 switch (offset) {
358 case offsetof(struct user_regs_struct, cs):
359 case offsetof(struct user_regs_struct, ds):
360 case offsetof(struct user_regs_struct, es):
361 case offsetof(struct user_regs_struct, fs):
362 case offsetof(struct user_regs_struct, gs):
363 case offsetof(struct user_regs_struct, ss):
364 return set_segment_reg(child, offset, value);
365
366 case offsetof(struct user_regs_struct, flags):
367 return set_flags(child, value);
368
369 #ifdef CONFIG_X86_64
370 case offsetof(struct user_regs_struct,fs_base):
371 if (value >= TASK_SIZE_MAX)
372 return -EIO;
373 /*
374 * When changing the FS base, use do_arch_prctl_64()
375 * to set the index to zero and to set the base
376 * as requested.
377 */
378 if (child->thread.fsbase != value)
379 return do_arch_prctl_64(child, ARCH_SET_FS, value);
380 return 0;
381 case offsetof(struct user_regs_struct,gs_base):
382 /*
383 * Exactly the same here as the %fs handling above.
384 */
385 if (value >= TASK_SIZE_MAX)
386 return -EIO;
387 if (child->thread.gsbase != value)
388 return do_arch_prctl_64(child, ARCH_SET_GS, value);
389 return 0;
390 #endif
391 }
392
393 *pt_regs_access(task_pt_regs(child), offset) = value;
394 return 0;
395 }
396
getreg(struct task_struct * task,unsigned long offset)397 static unsigned long getreg(struct task_struct *task, unsigned long offset)
398 {
399 switch (offset) {
400 case offsetof(struct user_regs_struct, cs):
401 case offsetof(struct user_regs_struct, ds):
402 case offsetof(struct user_regs_struct, es):
403 case offsetof(struct user_regs_struct, fs):
404 case offsetof(struct user_regs_struct, gs):
405 case offsetof(struct user_regs_struct, ss):
406 return get_segment_reg(task, offset);
407
408 case offsetof(struct user_regs_struct, flags):
409 return get_flags(task);
410
411 #ifdef CONFIG_X86_64
412 case offsetof(struct user_regs_struct, fs_base):
413 return x86_fsbase_read_task(task);
414 case offsetof(struct user_regs_struct, gs_base):
415 return x86_gsbase_read_task(task);
416 #endif
417 }
418
419 return *pt_regs_access(task_pt_regs(task), offset);
420 }
421
genregs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)422 static int genregs_get(struct task_struct *target,
423 const struct user_regset *regset,
424 unsigned int pos, unsigned int count,
425 void *kbuf, void __user *ubuf)
426 {
427 if (kbuf) {
428 unsigned long *k = kbuf;
429 while (count >= sizeof(*k)) {
430 *k++ = getreg(target, pos);
431 count -= sizeof(*k);
432 pos += sizeof(*k);
433 }
434 } else {
435 unsigned long __user *u = ubuf;
436 while (count >= sizeof(*u)) {
437 if (__put_user(getreg(target, pos), u++))
438 return -EFAULT;
439 count -= sizeof(*u);
440 pos += sizeof(*u);
441 }
442 }
443
444 return 0;
445 }
446
genregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)447 static int genregs_set(struct task_struct *target,
448 const struct user_regset *regset,
449 unsigned int pos, unsigned int count,
450 const void *kbuf, const void __user *ubuf)
451 {
452 int ret = 0;
453 if (kbuf) {
454 const unsigned long *k = kbuf;
455 while (count >= sizeof(*k) && !ret) {
456 ret = putreg(target, pos, *k++);
457 count -= sizeof(*k);
458 pos += sizeof(*k);
459 }
460 } else {
461 const unsigned long __user *u = ubuf;
462 while (count >= sizeof(*u) && !ret) {
463 unsigned long word;
464 ret = __get_user(word, u++);
465 if (ret)
466 break;
467 ret = putreg(target, pos, word);
468 count -= sizeof(*u);
469 pos += sizeof(*u);
470 }
471 }
472 return ret;
473 }
474
ptrace_triggered(struct perf_event * bp,struct perf_sample_data * data,struct pt_regs * regs)475 static void ptrace_triggered(struct perf_event *bp,
476 struct perf_sample_data *data,
477 struct pt_regs *regs)
478 {
479 int i;
480 struct thread_struct *thread = &(current->thread);
481
482 /*
483 * Store in the virtual DR6 register the fact that the breakpoint
484 * was hit so the thread's debugger will see it.
485 */
486 for (i = 0; i < HBP_NUM; i++) {
487 if (thread->ptrace_bps[i] == bp)
488 break;
489 }
490
491 thread->debugreg6 |= (DR_TRAP0 << i);
492 }
493
494 /*
495 * Walk through every ptrace breakpoints for this thread and
496 * build the dr7 value on top of their attributes.
497 *
498 */
ptrace_get_dr7(struct perf_event * bp[])499 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
500 {
501 int i;
502 int dr7 = 0;
503 struct arch_hw_breakpoint *info;
504
505 for (i = 0; i < HBP_NUM; i++) {
506 if (bp[i] && !bp[i]->attr.disabled) {
507 info = counter_arch_bp(bp[i]);
508 dr7 |= encode_dr7(i, info->len, info->type);
509 }
510 }
511
512 return dr7;
513 }
514
ptrace_fill_bp_fields(struct perf_event_attr * attr,int len,int type,bool disabled)515 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
516 int len, int type, bool disabled)
517 {
518 int err, bp_len, bp_type;
519
520 err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
521 if (!err) {
522 attr->bp_len = bp_len;
523 attr->bp_type = bp_type;
524 attr->disabled = disabled;
525 }
526
527 return err;
528 }
529
530 static struct perf_event *
ptrace_register_breakpoint(struct task_struct * tsk,int len,int type,unsigned long addr,bool disabled)531 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
532 unsigned long addr, bool disabled)
533 {
534 struct perf_event_attr attr;
535 int err;
536
537 ptrace_breakpoint_init(&attr);
538 attr.bp_addr = addr;
539
540 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
541 if (err)
542 return ERR_PTR(err);
543
544 return register_user_hw_breakpoint(&attr, ptrace_triggered,
545 NULL, tsk);
546 }
547
ptrace_modify_breakpoint(struct perf_event * bp,int len,int type,int disabled)548 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
549 int disabled)
550 {
551 struct perf_event_attr attr = bp->attr;
552 int err;
553
554 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
555 if (err)
556 return err;
557
558 return modify_user_hw_breakpoint(bp, &attr);
559 }
560
561 /*
562 * Handle ptrace writes to debug register 7.
563 */
ptrace_write_dr7(struct task_struct * tsk,unsigned long data)564 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
565 {
566 struct thread_struct *thread = &tsk->thread;
567 unsigned long old_dr7;
568 bool second_pass = false;
569 int i, rc, ret = 0;
570
571 data &= ~DR_CONTROL_RESERVED;
572 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
573
574 restore:
575 rc = 0;
576 for (i = 0; i < HBP_NUM; i++) {
577 unsigned len, type;
578 bool disabled = !decode_dr7(data, i, &len, &type);
579 struct perf_event *bp = thread->ptrace_bps[i];
580
581 if (!bp) {
582 if (disabled)
583 continue;
584
585 bp = ptrace_register_breakpoint(tsk,
586 len, type, 0, disabled);
587 if (IS_ERR(bp)) {
588 rc = PTR_ERR(bp);
589 break;
590 }
591
592 thread->ptrace_bps[i] = bp;
593 continue;
594 }
595
596 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
597 if (rc)
598 break;
599 }
600
601 /* Restore if the first pass failed, second_pass shouldn't fail. */
602 if (rc && !WARN_ON(second_pass)) {
603 ret = rc;
604 data = old_dr7;
605 second_pass = true;
606 goto restore;
607 }
608
609 return ret;
610 }
611
612 /*
613 * Handle PTRACE_PEEKUSR calls for the debug register area.
614 */
ptrace_get_debugreg(struct task_struct * tsk,int n)615 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
616 {
617 struct thread_struct *thread = &tsk->thread;
618 unsigned long val = 0;
619
620 if (n < HBP_NUM) {
621 int index = array_index_nospec(n, HBP_NUM);
622 struct perf_event *bp = thread->ptrace_bps[index];
623
624 if (bp)
625 val = bp->hw.info.address;
626 } else if (n == 6) {
627 val = thread->debugreg6;
628 } else if (n == 7) {
629 val = thread->ptrace_dr7;
630 }
631 return val;
632 }
633
ptrace_set_breakpoint_addr(struct task_struct * tsk,int nr,unsigned long addr)634 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
635 unsigned long addr)
636 {
637 struct thread_struct *t = &tsk->thread;
638 struct perf_event *bp = t->ptrace_bps[nr];
639 int err = 0;
640
641 if (!bp) {
642 /*
643 * Put stub len and type to create an inactive but correct bp.
644 *
645 * CHECKME: the previous code returned -EIO if the addr wasn't
646 * a valid task virtual addr. The new one will return -EINVAL in
647 * this case.
648 * -EINVAL may be what we want for in-kernel breakpoints users,
649 * but -EIO looks better for ptrace, since we refuse a register
650 * writing for the user. And anyway this is the previous
651 * behaviour.
652 */
653 bp = ptrace_register_breakpoint(tsk,
654 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
655 addr, true);
656 if (IS_ERR(bp))
657 err = PTR_ERR(bp);
658 else
659 t->ptrace_bps[nr] = bp;
660 } else {
661 struct perf_event_attr attr = bp->attr;
662
663 attr.bp_addr = addr;
664 err = modify_user_hw_breakpoint(bp, &attr);
665 }
666
667 return err;
668 }
669
670 /*
671 * Handle PTRACE_POKEUSR calls for the debug register area.
672 */
ptrace_set_debugreg(struct task_struct * tsk,int n,unsigned long val)673 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
674 unsigned long val)
675 {
676 struct thread_struct *thread = &tsk->thread;
677 /* There are no DR4 or DR5 registers */
678 int rc = -EIO;
679
680 if (n < HBP_NUM) {
681 rc = ptrace_set_breakpoint_addr(tsk, n, val);
682 } else if (n == 6) {
683 thread->debugreg6 = val;
684 rc = 0;
685 } else if (n == 7) {
686 rc = ptrace_write_dr7(tsk, val);
687 if (!rc)
688 thread->ptrace_dr7 = val;
689 }
690 return rc;
691 }
692
693 /*
694 * These access the current or another (stopped) task's io permission
695 * bitmap for debugging or core dump.
696 */
ioperm_active(struct task_struct * target,const struct user_regset * regset)697 static int ioperm_active(struct task_struct *target,
698 const struct user_regset *regset)
699 {
700 return target->thread.io_bitmap_max / regset->size;
701 }
702
ioperm_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)703 static int ioperm_get(struct task_struct *target,
704 const struct user_regset *regset,
705 unsigned int pos, unsigned int count,
706 void *kbuf, void __user *ubuf)
707 {
708 if (!target->thread.io_bitmap_ptr)
709 return -ENXIO;
710
711 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
712 target->thread.io_bitmap_ptr,
713 0, IO_BITMAP_BYTES);
714 }
715
716 /*
717 * Called by kernel/ptrace.c when detaching..
718 *
719 * Make sure the single step bit is not set.
720 */
ptrace_disable(struct task_struct * child)721 void ptrace_disable(struct task_struct *child)
722 {
723 user_disable_single_step(child);
724 }
725
726 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
727 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
728 #endif
729
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)730 long arch_ptrace(struct task_struct *child, long request,
731 unsigned long addr, unsigned long data)
732 {
733 int ret;
734 unsigned long __user *datap = (unsigned long __user *)data;
735
736 switch (request) {
737 /* read the word at location addr in the USER area. */
738 case PTRACE_PEEKUSR: {
739 unsigned long tmp;
740
741 ret = -EIO;
742 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
743 break;
744
745 tmp = 0; /* Default return condition */
746 if (addr < sizeof(struct user_regs_struct))
747 tmp = getreg(child, addr);
748 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
749 addr <= offsetof(struct user, u_debugreg[7])) {
750 addr -= offsetof(struct user, u_debugreg[0]);
751 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
752 }
753 ret = put_user(tmp, datap);
754 break;
755 }
756
757 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
758 ret = -EIO;
759 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
760 break;
761
762 if (addr < sizeof(struct user_regs_struct))
763 ret = putreg(child, addr, data);
764 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
765 addr <= offsetof(struct user, u_debugreg[7])) {
766 addr -= offsetof(struct user, u_debugreg[0]);
767 ret = ptrace_set_debugreg(child,
768 addr / sizeof(data), data);
769 }
770 break;
771
772 case PTRACE_GETREGS: /* Get all gp regs from the child. */
773 return copy_regset_to_user(child,
774 task_user_regset_view(current),
775 REGSET_GENERAL,
776 0, sizeof(struct user_regs_struct),
777 datap);
778
779 case PTRACE_SETREGS: /* Set all gp regs in the child. */
780 return copy_regset_from_user(child,
781 task_user_regset_view(current),
782 REGSET_GENERAL,
783 0, sizeof(struct user_regs_struct),
784 datap);
785
786 case PTRACE_GETFPREGS: /* Get the child FPU state. */
787 return copy_regset_to_user(child,
788 task_user_regset_view(current),
789 REGSET_FP,
790 0, sizeof(struct user_i387_struct),
791 datap);
792
793 case PTRACE_SETFPREGS: /* Set the child FPU state. */
794 return copy_regset_from_user(child,
795 task_user_regset_view(current),
796 REGSET_FP,
797 0, sizeof(struct user_i387_struct),
798 datap);
799
800 #ifdef CONFIG_X86_32
801 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
802 return copy_regset_to_user(child, &user_x86_32_view,
803 REGSET_XFP,
804 0, sizeof(struct user_fxsr_struct),
805 datap) ? -EIO : 0;
806
807 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
808 return copy_regset_from_user(child, &user_x86_32_view,
809 REGSET_XFP,
810 0, sizeof(struct user_fxsr_struct),
811 datap) ? -EIO : 0;
812 #endif
813
814 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
815 case PTRACE_GET_THREAD_AREA:
816 if ((int) addr < 0)
817 return -EIO;
818 ret = do_get_thread_area(child, addr,
819 (struct user_desc __user *)data);
820 break;
821
822 case PTRACE_SET_THREAD_AREA:
823 if ((int) addr < 0)
824 return -EIO;
825 ret = do_set_thread_area(child, addr,
826 (struct user_desc __user *)data, 0);
827 break;
828 #endif
829
830 #ifdef CONFIG_X86_64
831 /* normal 64bit interface to access TLS data.
832 Works just like arch_prctl, except that the arguments
833 are reversed. */
834 case PTRACE_ARCH_PRCTL:
835 ret = do_arch_prctl_64(child, data, addr);
836 break;
837 #endif
838
839 default:
840 ret = ptrace_request(child, request, addr, data);
841 break;
842 }
843
844 return ret;
845 }
846
847 #ifdef CONFIG_IA32_EMULATION
848
849 #include <linux/compat.h>
850 #include <linux/syscalls.h>
851 #include <asm/ia32.h>
852 #include <asm/user32.h>
853
854 #define R32(l,q) \
855 case offsetof(struct user32, regs.l): \
856 regs->q = value; break
857
858 #define SEG32(rs) \
859 case offsetof(struct user32, regs.rs): \
860 return set_segment_reg(child, \
861 offsetof(struct user_regs_struct, rs), \
862 value); \
863 break
864
putreg32(struct task_struct * child,unsigned regno,u32 value)865 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
866 {
867 struct pt_regs *regs = task_pt_regs(child);
868
869 switch (regno) {
870
871 SEG32(cs);
872 SEG32(ds);
873 SEG32(es);
874 SEG32(fs);
875 SEG32(gs);
876 SEG32(ss);
877
878 R32(ebx, bx);
879 R32(ecx, cx);
880 R32(edx, dx);
881 R32(edi, di);
882 R32(esi, si);
883 R32(ebp, bp);
884 R32(eax, ax);
885 R32(eip, ip);
886 R32(esp, sp);
887
888 case offsetof(struct user32, regs.orig_eax):
889 /*
890 * Warning: bizarre corner case fixup here. A 32-bit
891 * debugger setting orig_eax to -1 wants to disable
892 * syscall restart. Make sure that the syscall
893 * restart code sign-extends orig_ax. Also make sure
894 * we interpret the -ERESTART* codes correctly if
895 * loaded into regs->ax in case the task is not
896 * actually still sitting at the exit from a 32-bit
897 * syscall with TS_COMPAT still set.
898 */
899 regs->orig_ax = value;
900 if (syscall_get_nr(child, regs) >= 0)
901 child->thread_info.status |= TS_I386_REGS_POKED;
902 break;
903
904 case offsetof(struct user32, regs.eflags):
905 return set_flags(child, value);
906
907 case offsetof(struct user32, u_debugreg[0]) ...
908 offsetof(struct user32, u_debugreg[7]):
909 regno -= offsetof(struct user32, u_debugreg[0]);
910 return ptrace_set_debugreg(child, regno / 4, value);
911
912 default:
913 if (regno > sizeof(struct user32) || (regno & 3))
914 return -EIO;
915
916 /*
917 * Other dummy fields in the virtual user structure
918 * are ignored
919 */
920 break;
921 }
922 return 0;
923 }
924
925 #undef R32
926 #undef SEG32
927
928 #define R32(l,q) \
929 case offsetof(struct user32, regs.l): \
930 *val = regs->q; break
931
932 #define SEG32(rs) \
933 case offsetof(struct user32, regs.rs): \
934 *val = get_segment_reg(child, \
935 offsetof(struct user_regs_struct, rs)); \
936 break
937
getreg32(struct task_struct * child,unsigned regno,u32 * val)938 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
939 {
940 struct pt_regs *regs = task_pt_regs(child);
941
942 switch (regno) {
943
944 SEG32(ds);
945 SEG32(es);
946 SEG32(fs);
947 SEG32(gs);
948
949 R32(cs, cs);
950 R32(ss, ss);
951 R32(ebx, bx);
952 R32(ecx, cx);
953 R32(edx, dx);
954 R32(edi, di);
955 R32(esi, si);
956 R32(ebp, bp);
957 R32(eax, ax);
958 R32(orig_eax, orig_ax);
959 R32(eip, ip);
960 R32(esp, sp);
961
962 case offsetof(struct user32, regs.eflags):
963 *val = get_flags(child);
964 break;
965
966 case offsetof(struct user32, u_debugreg[0]) ...
967 offsetof(struct user32, u_debugreg[7]):
968 regno -= offsetof(struct user32, u_debugreg[0]);
969 *val = ptrace_get_debugreg(child, regno / 4);
970 break;
971
972 default:
973 if (regno > sizeof(struct user32) || (regno & 3))
974 return -EIO;
975
976 /*
977 * Other dummy fields in the virtual user structure
978 * are ignored
979 */
980 *val = 0;
981 break;
982 }
983 return 0;
984 }
985
986 #undef R32
987 #undef SEG32
988
genregs32_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)989 static int genregs32_get(struct task_struct *target,
990 const struct user_regset *regset,
991 unsigned int pos, unsigned int count,
992 void *kbuf, void __user *ubuf)
993 {
994 if (kbuf) {
995 compat_ulong_t *k = kbuf;
996 while (count >= sizeof(*k)) {
997 getreg32(target, pos, k++);
998 count -= sizeof(*k);
999 pos += sizeof(*k);
1000 }
1001 } else {
1002 compat_ulong_t __user *u = ubuf;
1003 while (count >= sizeof(*u)) {
1004 compat_ulong_t word;
1005 getreg32(target, pos, &word);
1006 if (__put_user(word, u++))
1007 return -EFAULT;
1008 count -= sizeof(*u);
1009 pos += sizeof(*u);
1010 }
1011 }
1012
1013 return 0;
1014 }
1015
genregs32_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)1016 static int genregs32_set(struct task_struct *target,
1017 const struct user_regset *regset,
1018 unsigned int pos, unsigned int count,
1019 const void *kbuf, const void __user *ubuf)
1020 {
1021 int ret = 0;
1022 if (kbuf) {
1023 const compat_ulong_t *k = kbuf;
1024 while (count >= sizeof(*k) && !ret) {
1025 ret = putreg32(target, pos, *k++);
1026 count -= sizeof(*k);
1027 pos += sizeof(*k);
1028 }
1029 } else {
1030 const compat_ulong_t __user *u = ubuf;
1031 while (count >= sizeof(*u) && !ret) {
1032 compat_ulong_t word;
1033 ret = __get_user(word, u++);
1034 if (ret)
1035 break;
1036 ret = putreg32(target, pos, word);
1037 count -= sizeof(*u);
1038 pos += sizeof(*u);
1039 }
1040 }
1041 return ret;
1042 }
1043
ia32_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)1044 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1045 compat_ulong_t caddr, compat_ulong_t cdata)
1046 {
1047 unsigned long addr = caddr;
1048 unsigned long data = cdata;
1049 void __user *datap = compat_ptr(data);
1050 int ret;
1051 __u32 val;
1052
1053 switch (request) {
1054 case PTRACE_PEEKUSR:
1055 ret = getreg32(child, addr, &val);
1056 if (ret == 0)
1057 ret = put_user(val, (__u32 __user *)datap);
1058 break;
1059
1060 case PTRACE_POKEUSR:
1061 ret = putreg32(child, addr, data);
1062 break;
1063
1064 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1065 return copy_regset_to_user(child, &user_x86_32_view,
1066 REGSET_GENERAL,
1067 0, sizeof(struct user_regs_struct32),
1068 datap);
1069
1070 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1071 return copy_regset_from_user(child, &user_x86_32_view,
1072 REGSET_GENERAL, 0,
1073 sizeof(struct user_regs_struct32),
1074 datap);
1075
1076 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1077 return copy_regset_to_user(child, &user_x86_32_view,
1078 REGSET_FP, 0,
1079 sizeof(struct user_i387_ia32_struct),
1080 datap);
1081
1082 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1083 return copy_regset_from_user(
1084 child, &user_x86_32_view, REGSET_FP,
1085 0, sizeof(struct user_i387_ia32_struct), datap);
1086
1087 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1088 return copy_regset_to_user(child, &user_x86_32_view,
1089 REGSET_XFP, 0,
1090 sizeof(struct user32_fxsr_struct),
1091 datap);
1092
1093 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1094 return copy_regset_from_user(child, &user_x86_32_view,
1095 REGSET_XFP, 0,
1096 sizeof(struct user32_fxsr_struct),
1097 datap);
1098
1099 case PTRACE_GET_THREAD_AREA:
1100 case PTRACE_SET_THREAD_AREA:
1101 return arch_ptrace(child, request, addr, data);
1102
1103 default:
1104 return compat_ptrace_request(child, request, addr, data);
1105 }
1106
1107 return ret;
1108 }
1109 #endif /* CONFIG_IA32_EMULATION */
1110
1111 #ifdef CONFIG_X86_X32_ABI
x32_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)1112 static long x32_arch_ptrace(struct task_struct *child,
1113 compat_long_t request, compat_ulong_t caddr,
1114 compat_ulong_t cdata)
1115 {
1116 unsigned long addr = caddr;
1117 unsigned long data = cdata;
1118 void __user *datap = compat_ptr(data);
1119 int ret;
1120
1121 switch (request) {
1122 /* Read 32bits at location addr in the USER area. Only allow
1123 to return the lower 32bits of segment and debug registers. */
1124 case PTRACE_PEEKUSR: {
1125 u32 tmp;
1126
1127 ret = -EIO;
1128 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1129 addr < offsetof(struct user_regs_struct, cs))
1130 break;
1131
1132 tmp = 0; /* Default return condition */
1133 if (addr < sizeof(struct user_regs_struct))
1134 tmp = getreg(child, addr);
1135 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1136 addr <= offsetof(struct user, u_debugreg[7])) {
1137 addr -= offsetof(struct user, u_debugreg[0]);
1138 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1139 }
1140 ret = put_user(tmp, (__u32 __user *)datap);
1141 break;
1142 }
1143
1144 /* Write the word at location addr in the USER area. Only allow
1145 to update segment and debug registers with the upper 32bits
1146 zero-extended. */
1147 case PTRACE_POKEUSR:
1148 ret = -EIO;
1149 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1150 addr < offsetof(struct user_regs_struct, cs))
1151 break;
1152
1153 if (addr < sizeof(struct user_regs_struct))
1154 ret = putreg(child, addr, data);
1155 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1156 addr <= offsetof(struct user, u_debugreg[7])) {
1157 addr -= offsetof(struct user, u_debugreg[0]);
1158 ret = ptrace_set_debugreg(child,
1159 addr / sizeof(data), data);
1160 }
1161 break;
1162
1163 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1164 return copy_regset_to_user(child,
1165 task_user_regset_view(current),
1166 REGSET_GENERAL,
1167 0, sizeof(struct user_regs_struct),
1168 datap);
1169
1170 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1171 return copy_regset_from_user(child,
1172 task_user_regset_view(current),
1173 REGSET_GENERAL,
1174 0, sizeof(struct user_regs_struct),
1175 datap);
1176
1177 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1178 return copy_regset_to_user(child,
1179 task_user_regset_view(current),
1180 REGSET_FP,
1181 0, sizeof(struct user_i387_struct),
1182 datap);
1183
1184 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1185 return copy_regset_from_user(child,
1186 task_user_regset_view(current),
1187 REGSET_FP,
1188 0, sizeof(struct user_i387_struct),
1189 datap);
1190
1191 default:
1192 return compat_ptrace_request(child, request, addr, data);
1193 }
1194
1195 return ret;
1196 }
1197 #endif
1198
1199 #ifdef CONFIG_COMPAT
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)1200 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1201 compat_ulong_t caddr, compat_ulong_t cdata)
1202 {
1203 #ifdef CONFIG_X86_X32_ABI
1204 if (!in_ia32_syscall())
1205 return x32_arch_ptrace(child, request, caddr, cdata);
1206 #endif
1207 #ifdef CONFIG_IA32_EMULATION
1208 return ia32_arch_ptrace(child, request, caddr, cdata);
1209 #else
1210 return 0;
1211 #endif
1212 }
1213 #endif /* CONFIG_COMPAT */
1214
1215 #ifdef CONFIG_X86_64
1216
1217 static struct user_regset x86_64_regsets[] __ro_after_init = {
1218 [REGSET_GENERAL] = {
1219 .core_note_type = NT_PRSTATUS,
1220 .n = sizeof(struct user_regs_struct) / sizeof(long),
1221 .size = sizeof(long), .align = sizeof(long),
1222 .get = genregs_get, .set = genregs_set
1223 },
1224 [REGSET_FP] = {
1225 .core_note_type = NT_PRFPREG,
1226 .n = sizeof(struct user_i387_struct) / sizeof(long),
1227 .size = sizeof(long), .align = sizeof(long),
1228 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1229 },
1230 [REGSET_XSTATE] = {
1231 .core_note_type = NT_X86_XSTATE,
1232 .size = sizeof(u64), .align = sizeof(u64),
1233 .active = xstateregs_active, .get = xstateregs_get,
1234 .set = xstateregs_set
1235 },
1236 [REGSET_IOPERM64] = {
1237 .core_note_type = NT_386_IOPERM,
1238 .n = IO_BITMAP_LONGS,
1239 .size = sizeof(long), .align = sizeof(long),
1240 .active = ioperm_active, .get = ioperm_get
1241 },
1242 };
1243
1244 static const struct user_regset_view user_x86_64_view = {
1245 .name = "x86_64", .e_machine = EM_X86_64,
1246 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1247 };
1248
1249 #else /* CONFIG_X86_32 */
1250
1251 #define user_regs_struct32 user_regs_struct
1252 #define genregs32_get genregs_get
1253 #define genregs32_set genregs_set
1254
1255 #endif /* CONFIG_X86_64 */
1256
1257 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1258 static struct user_regset x86_32_regsets[] __ro_after_init = {
1259 [REGSET_GENERAL] = {
1260 .core_note_type = NT_PRSTATUS,
1261 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1262 .size = sizeof(u32), .align = sizeof(u32),
1263 .get = genregs32_get, .set = genregs32_set
1264 },
1265 [REGSET_FP] = {
1266 .core_note_type = NT_PRFPREG,
1267 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1268 .size = sizeof(u32), .align = sizeof(u32),
1269 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1270 },
1271 [REGSET_XFP] = {
1272 .core_note_type = NT_PRXFPREG,
1273 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1274 .size = sizeof(u32), .align = sizeof(u32),
1275 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1276 },
1277 [REGSET_XSTATE] = {
1278 .core_note_type = NT_X86_XSTATE,
1279 .size = sizeof(u64), .align = sizeof(u64),
1280 .active = xstateregs_active, .get = xstateregs_get,
1281 .set = xstateregs_set
1282 },
1283 [REGSET_TLS] = {
1284 .core_note_type = NT_386_TLS,
1285 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1286 .size = sizeof(struct user_desc),
1287 .align = sizeof(struct user_desc),
1288 .active = regset_tls_active,
1289 .get = regset_tls_get, .set = regset_tls_set
1290 },
1291 [REGSET_IOPERM32] = {
1292 .core_note_type = NT_386_IOPERM,
1293 .n = IO_BITMAP_BYTES / sizeof(u32),
1294 .size = sizeof(u32), .align = sizeof(u32),
1295 .active = ioperm_active, .get = ioperm_get
1296 },
1297 };
1298
1299 static const struct user_regset_view user_x86_32_view = {
1300 .name = "i386", .e_machine = EM_386,
1301 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1302 };
1303 #endif
1304
1305 /*
1306 * This represents bytes 464..511 in the memory layout exported through
1307 * the REGSET_XSTATE interface.
1308 */
1309 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1310
update_regset_xstate_info(unsigned int size,u64 xstate_mask)1311 void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1312 {
1313 #ifdef CONFIG_X86_64
1314 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1315 #endif
1316 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1317 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1318 #endif
1319 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1320 }
1321
task_user_regset_view(struct task_struct * task)1322 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1323 {
1324 #ifdef CONFIG_IA32_EMULATION
1325 if (!user_64bit_mode(task_pt_regs(task)))
1326 #endif
1327 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1328 return &user_x86_32_view;
1329 #endif
1330 #ifdef CONFIG_X86_64
1331 return &user_x86_64_view;
1332 #endif
1333 }
1334
send_sigtrap(struct pt_regs * regs,int error_code,int si_code)1335 void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1336 {
1337 struct task_struct *tsk = current;
1338
1339 tsk->thread.trap_nr = X86_TRAP_DB;
1340 tsk->thread.error_code = error_code;
1341
1342 /* Send us the fake SIGTRAP */
1343 force_sig_fault(SIGTRAP, si_code,
1344 user_mode(regs) ? (void __user *)regs->ip : NULL);
1345 }
1346
user_single_step_report(struct pt_regs * regs)1347 void user_single_step_report(struct pt_regs *regs)
1348 {
1349 send_sigtrap(regs, 0, TRAP_BRKPT);
1350 }
1351