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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
48enum 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
58struct 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
66static 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 */
106int 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 */
122const 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 */
149static 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
158static 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
164static 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
181static 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
224static 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
230static 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
271static 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
322static 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
335static 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
354static 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
397static 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
422static 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
447static 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
475static 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 */
499static 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
515static 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
530static struct perf_event *
531ptrace_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
548static 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 */
564static 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
574restore:
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 */
615static 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
634static 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 */
673static 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 */
697static 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
703static 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 */
721void 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
727static const struct user_regset_view user_x86_32_view; /* Initialized below. */
728#endif
729
730long 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
865static 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
938static 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
989static 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
1016static 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
1044static 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
1112static 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
1200long 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
1217static 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
1244static 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
1258static 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
1299static 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 */
1309u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1310
1311void __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
1322const 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
1335void 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
1347void user_single_step_report(struct pt_regs *regs)
1348{
1349 send_sigtrap(regs, 0, TRAP_BRKPT);
1350}
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/user.h>
17#include <linux/elf.h>
18#include <linux/security.h>
19#include <linux/audit.h>
20#include <linux/seccomp.h>
21#include <linux/signal.h>
22#include <linux/perf_event.h>
23#include <linux/hw_breakpoint.h>
24#include <linux/rcupdate.h>
25#include <linux/export.h>
26#include <linux/context_tracking.h>
27#include <linux/nospec.h>
28
29#include <linux/uaccess.h>
30#include <asm/processor.h>
31#include <asm/fpu/signal.h>
32#include <asm/fpu/regset.h>
33#include <asm/fpu/xstate.h>
34#include <asm/debugreg.h>
35#include <asm/ldt.h>
36#include <asm/desc.h>
37#include <asm/prctl.h>
38#include <asm/proto.h>
39#include <asm/hw_breakpoint.h>
40#include <asm/traps.h>
41#include <asm/syscall.h>
42#include <asm/fsgsbase.h>
43#include <asm/io_bitmap.h>
44
45#include "tls.h"
46
47enum x86_regset_32 {
48 REGSET32_GENERAL,
49 REGSET32_FP,
50 REGSET32_XFP,
51 REGSET32_XSTATE,
52 REGSET32_TLS,
53 REGSET32_IOPERM,
54};
55
56enum x86_regset_64 {
57 REGSET64_GENERAL,
58 REGSET64_FP,
59 REGSET64_IOPERM,
60 REGSET64_XSTATE,
61 REGSET64_SSP,
62};
63
64#define REGSET_GENERAL \
65({ \
66 BUILD_BUG_ON((int)REGSET32_GENERAL != (int)REGSET64_GENERAL); \
67 REGSET32_GENERAL; \
68})
69
70#define REGSET_FP \
71({ \
72 BUILD_BUG_ON((int)REGSET32_FP != (int)REGSET64_FP); \
73 REGSET32_FP; \
74})
75
76
77struct pt_regs_offset {
78 const char *name;
79 int offset;
80};
81
82#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
83#define REG_OFFSET_END {.name = NULL, .offset = 0}
84
85static const struct pt_regs_offset regoffset_table[] = {
86#ifdef CONFIG_X86_64
87 REG_OFFSET_NAME(r15),
88 REG_OFFSET_NAME(r14),
89 REG_OFFSET_NAME(r13),
90 REG_OFFSET_NAME(r12),
91 REG_OFFSET_NAME(r11),
92 REG_OFFSET_NAME(r10),
93 REG_OFFSET_NAME(r9),
94 REG_OFFSET_NAME(r8),
95#endif
96 REG_OFFSET_NAME(bx),
97 REG_OFFSET_NAME(cx),
98 REG_OFFSET_NAME(dx),
99 REG_OFFSET_NAME(si),
100 REG_OFFSET_NAME(di),
101 REG_OFFSET_NAME(bp),
102 REG_OFFSET_NAME(ax),
103#ifdef CONFIG_X86_32
104 REG_OFFSET_NAME(ds),
105 REG_OFFSET_NAME(es),
106 REG_OFFSET_NAME(fs),
107 REG_OFFSET_NAME(gs),
108#endif
109 REG_OFFSET_NAME(orig_ax),
110 REG_OFFSET_NAME(ip),
111 REG_OFFSET_NAME(cs),
112 REG_OFFSET_NAME(flags),
113 REG_OFFSET_NAME(sp),
114 REG_OFFSET_NAME(ss),
115 REG_OFFSET_END,
116};
117
118/**
119 * regs_query_register_offset() - query register offset from its name
120 * @name: the name of a register
121 *
122 * regs_query_register_offset() returns the offset of a register in struct
123 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
124 */
125int regs_query_register_offset(const char *name)
126{
127 const struct pt_regs_offset *roff;
128 for (roff = regoffset_table; roff->name != NULL; roff++)
129 if (!strcmp(roff->name, name))
130 return roff->offset;
131 return -EINVAL;
132}
133
134/**
135 * regs_query_register_name() - query register name from its offset
136 * @offset: the offset of a register in struct pt_regs.
137 *
138 * regs_query_register_name() returns the name of a register from its
139 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
140 */
141const char *regs_query_register_name(unsigned int offset)
142{
143 const struct pt_regs_offset *roff;
144 for (roff = regoffset_table; roff->name != NULL; roff++)
145 if (roff->offset == offset)
146 return roff->name;
147 return NULL;
148}
149
150/*
151 * does not yet catch signals sent when the child dies.
152 * in exit.c or in signal.c.
153 */
154
155/*
156 * Determines which flags the user has access to [1 = access, 0 = no access].
157 */
158#define FLAG_MASK_32 ((unsigned long) \
159 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
160 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
161 X86_EFLAGS_SF | X86_EFLAGS_TF | \
162 X86_EFLAGS_DF | X86_EFLAGS_OF | \
163 X86_EFLAGS_RF | X86_EFLAGS_AC))
164
165/*
166 * Determines whether a value may be installed in a segment register.
167 */
168static inline bool invalid_selector(u16 value)
169{
170 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
171}
172
173#ifdef CONFIG_X86_32
174
175#define FLAG_MASK FLAG_MASK_32
176
177static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
178{
179 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
180 return ®s->bx + (regno >> 2);
181}
182
183static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
184{
185 /*
186 * Returning the value truncates it to 16 bits.
187 */
188 unsigned int retval;
189 if (offset != offsetof(struct user_regs_struct, gs))
190 retval = *pt_regs_access(task_pt_regs(task), offset);
191 else {
192 if (task == current)
193 savesegment(gs, retval);
194 else
195 retval = task->thread.gs;
196 }
197 return retval;
198}
199
200static int set_segment_reg(struct task_struct *task,
201 unsigned long offset, u16 value)
202{
203 if (WARN_ON_ONCE(task == current))
204 return -EIO;
205
206 /*
207 * The value argument was already truncated to 16 bits.
208 */
209 if (invalid_selector(value))
210 return -EIO;
211
212 /*
213 * For %cs and %ss we cannot permit a null selector.
214 * We can permit a bogus selector as long as it has USER_RPL.
215 * Null selectors are fine for other segment registers, but
216 * we will never get back to user mode with invalid %cs or %ss
217 * and will take the trap in iret instead. Much code relies
218 * on user_mode() to distinguish a user trap frame (which can
219 * safely use invalid selectors) from a kernel trap frame.
220 */
221 switch (offset) {
222 case offsetof(struct user_regs_struct, cs):
223 case offsetof(struct user_regs_struct, ss):
224 if (unlikely(value == 0))
225 return -EIO;
226 fallthrough;
227
228 default:
229 *pt_regs_access(task_pt_regs(task), offset) = value;
230 break;
231
232 case offsetof(struct user_regs_struct, gs):
233 task->thread.gs = value;
234 }
235
236 return 0;
237}
238
239#else /* CONFIG_X86_64 */
240
241#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
242
243static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
244{
245 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
246 return ®s->r15 + (offset / sizeof(regs->r15));
247}
248
249static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
250{
251 /*
252 * Returning the value truncates it to 16 bits.
253 */
254 unsigned int seg;
255
256 switch (offset) {
257 case offsetof(struct user_regs_struct, fs):
258 if (task == current) {
259 /* Older gas can't assemble movq %?s,%r?? */
260 asm("movl %%fs,%0" : "=r" (seg));
261 return seg;
262 }
263 return task->thread.fsindex;
264 case offsetof(struct user_regs_struct, gs):
265 if (task == current) {
266 asm("movl %%gs,%0" : "=r" (seg));
267 return seg;
268 }
269 return task->thread.gsindex;
270 case offsetof(struct user_regs_struct, ds):
271 if (task == current) {
272 asm("movl %%ds,%0" : "=r" (seg));
273 return seg;
274 }
275 return task->thread.ds;
276 case offsetof(struct user_regs_struct, es):
277 if (task == current) {
278 asm("movl %%es,%0" : "=r" (seg));
279 return seg;
280 }
281 return task->thread.es;
282
283 case offsetof(struct user_regs_struct, cs):
284 case offsetof(struct user_regs_struct, ss):
285 break;
286 }
287 return *pt_regs_access(task_pt_regs(task), offset);
288}
289
290static int set_segment_reg(struct task_struct *task,
291 unsigned long offset, u16 value)
292{
293 if (WARN_ON_ONCE(task == current))
294 return -EIO;
295
296 /*
297 * The value argument was already truncated to 16 bits.
298 */
299 if (invalid_selector(value))
300 return -EIO;
301
302 /*
303 * Writes to FS and GS will change the stored selector. Whether
304 * this changes the segment base as well depends on whether
305 * FSGSBASE is enabled.
306 */
307
308 switch (offset) {
309 case offsetof(struct user_regs_struct,fs):
310 task->thread.fsindex = value;
311 break;
312 case offsetof(struct user_regs_struct,gs):
313 task->thread.gsindex = value;
314 break;
315 case offsetof(struct user_regs_struct,ds):
316 task->thread.ds = value;
317 break;
318 case offsetof(struct user_regs_struct,es):
319 task->thread.es = value;
320 break;
321
322 /*
323 * Can't actually change these in 64-bit mode.
324 */
325 case offsetof(struct user_regs_struct,cs):
326 if (unlikely(value == 0))
327 return -EIO;
328 task_pt_regs(task)->cs = value;
329 break;
330 case offsetof(struct user_regs_struct,ss):
331 if (unlikely(value == 0))
332 return -EIO;
333 task_pt_regs(task)->ss = value;
334 break;
335 }
336
337 return 0;
338}
339
340#endif /* CONFIG_X86_32 */
341
342static unsigned long get_flags(struct task_struct *task)
343{
344 unsigned long retval = task_pt_regs(task)->flags;
345
346 /*
347 * If the debugger set TF, hide it from the readout.
348 */
349 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
350 retval &= ~X86_EFLAGS_TF;
351
352 return retval;
353}
354
355static int set_flags(struct task_struct *task, unsigned long value)
356{
357 struct pt_regs *regs = task_pt_regs(task);
358
359 /*
360 * If the user value contains TF, mark that
361 * it was not "us" (the debugger) that set it.
362 * If not, make sure it stays set if we had.
363 */
364 if (value & X86_EFLAGS_TF)
365 clear_tsk_thread_flag(task, TIF_FORCED_TF);
366 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
367 value |= X86_EFLAGS_TF;
368
369 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
370
371 return 0;
372}
373
374static int putreg(struct task_struct *child,
375 unsigned long offset, unsigned long value)
376{
377 switch (offset) {
378 case offsetof(struct user_regs_struct, cs):
379 case offsetof(struct user_regs_struct, ds):
380 case offsetof(struct user_regs_struct, es):
381 case offsetof(struct user_regs_struct, fs):
382 case offsetof(struct user_regs_struct, gs):
383 case offsetof(struct user_regs_struct, ss):
384 return set_segment_reg(child, offset, value);
385
386 case offsetof(struct user_regs_struct, flags):
387 return set_flags(child, value);
388
389#ifdef CONFIG_X86_64
390 case offsetof(struct user_regs_struct,fs_base):
391 if (value >= TASK_SIZE_MAX)
392 return -EIO;
393 x86_fsbase_write_task(child, value);
394 return 0;
395 case offsetof(struct user_regs_struct,gs_base):
396 if (value >= TASK_SIZE_MAX)
397 return -EIO;
398 x86_gsbase_write_task(child, value);
399 return 0;
400#endif
401 }
402
403 *pt_regs_access(task_pt_regs(child), offset) = value;
404 return 0;
405}
406
407static unsigned long getreg(struct task_struct *task, unsigned long offset)
408{
409 switch (offset) {
410 case offsetof(struct user_regs_struct, cs):
411 case offsetof(struct user_regs_struct, ds):
412 case offsetof(struct user_regs_struct, es):
413 case offsetof(struct user_regs_struct, fs):
414 case offsetof(struct user_regs_struct, gs):
415 case offsetof(struct user_regs_struct, ss):
416 return get_segment_reg(task, offset);
417
418 case offsetof(struct user_regs_struct, flags):
419 return get_flags(task);
420
421#ifdef CONFIG_X86_64
422 case offsetof(struct user_regs_struct, fs_base):
423 return x86_fsbase_read_task(task);
424 case offsetof(struct user_regs_struct, gs_base):
425 return x86_gsbase_read_task(task);
426#endif
427 }
428
429 return *pt_regs_access(task_pt_regs(task), offset);
430}
431
432static int genregs_get(struct task_struct *target,
433 const struct user_regset *regset,
434 struct membuf to)
435{
436 int reg;
437
438 for (reg = 0; to.left; reg++)
439 membuf_store(&to, getreg(target, reg * sizeof(unsigned long)));
440 return 0;
441}
442
443static int genregs_set(struct task_struct *target,
444 const struct user_regset *regset,
445 unsigned int pos, unsigned int count,
446 const void *kbuf, const void __user *ubuf)
447{
448 int ret = 0;
449 if (kbuf) {
450 const unsigned long *k = kbuf;
451 while (count >= sizeof(*k) && !ret) {
452 ret = putreg(target, pos, *k++);
453 count -= sizeof(*k);
454 pos += sizeof(*k);
455 }
456 } else {
457 const unsigned long __user *u = ubuf;
458 while (count >= sizeof(*u) && !ret) {
459 unsigned long word;
460 ret = __get_user(word, u++);
461 if (ret)
462 break;
463 ret = putreg(target, pos, word);
464 count -= sizeof(*u);
465 pos += sizeof(*u);
466 }
467 }
468 return ret;
469}
470
471static void ptrace_triggered(struct perf_event *bp,
472 struct perf_sample_data *data,
473 struct pt_regs *regs)
474{
475 int i;
476 struct thread_struct *thread = &(current->thread);
477
478 /*
479 * Store in the virtual DR6 register the fact that the breakpoint
480 * was hit so the thread's debugger will see it.
481 */
482 for (i = 0; i < HBP_NUM; i++) {
483 if (thread->ptrace_bps[i] == bp)
484 break;
485 }
486
487 thread->virtual_dr6 |= (DR_TRAP0 << i);
488}
489
490/*
491 * Walk through every ptrace breakpoints for this thread and
492 * build the dr7 value on top of their attributes.
493 *
494 */
495static unsigned long ptrace_get_dr7(struct perf_event *bp[])
496{
497 int i;
498 int dr7 = 0;
499 struct arch_hw_breakpoint *info;
500
501 for (i = 0; i < HBP_NUM; i++) {
502 if (bp[i] && !bp[i]->attr.disabled) {
503 info = counter_arch_bp(bp[i]);
504 dr7 |= encode_dr7(i, info->len, info->type);
505 }
506 }
507
508 return dr7;
509}
510
511static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
512 int len, int type, bool disabled)
513{
514 int err, bp_len, bp_type;
515
516 err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
517 if (!err) {
518 attr->bp_len = bp_len;
519 attr->bp_type = bp_type;
520 attr->disabled = disabled;
521 }
522
523 return err;
524}
525
526static struct perf_event *
527ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
528 unsigned long addr, bool disabled)
529{
530 struct perf_event_attr attr;
531 int err;
532
533 ptrace_breakpoint_init(&attr);
534 attr.bp_addr = addr;
535
536 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
537 if (err)
538 return ERR_PTR(err);
539
540 return register_user_hw_breakpoint(&attr, ptrace_triggered,
541 NULL, tsk);
542}
543
544static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
545 int disabled)
546{
547 struct perf_event_attr attr = bp->attr;
548 int err;
549
550 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
551 if (err)
552 return err;
553
554 return modify_user_hw_breakpoint(bp, &attr);
555}
556
557/*
558 * Handle ptrace writes to debug register 7.
559 */
560static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
561{
562 struct thread_struct *thread = &tsk->thread;
563 unsigned long old_dr7;
564 bool second_pass = false;
565 int i, rc, ret = 0;
566
567 data &= ~DR_CONTROL_RESERVED;
568 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
569
570restore:
571 rc = 0;
572 for (i = 0; i < HBP_NUM; i++) {
573 unsigned len, type;
574 bool disabled = !decode_dr7(data, i, &len, &type);
575 struct perf_event *bp = thread->ptrace_bps[i];
576
577 if (!bp) {
578 if (disabled)
579 continue;
580
581 bp = ptrace_register_breakpoint(tsk,
582 len, type, 0, disabled);
583 if (IS_ERR(bp)) {
584 rc = PTR_ERR(bp);
585 break;
586 }
587
588 thread->ptrace_bps[i] = bp;
589 continue;
590 }
591
592 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
593 if (rc)
594 break;
595 }
596
597 /* Restore if the first pass failed, second_pass shouldn't fail. */
598 if (rc && !WARN_ON(second_pass)) {
599 ret = rc;
600 data = old_dr7;
601 second_pass = true;
602 goto restore;
603 }
604
605 return ret;
606}
607
608/*
609 * Handle PTRACE_PEEKUSR calls for the debug register area.
610 */
611static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
612{
613 struct thread_struct *thread = &tsk->thread;
614 unsigned long val = 0;
615
616 if (n < HBP_NUM) {
617 int index = array_index_nospec(n, HBP_NUM);
618 struct perf_event *bp = thread->ptrace_bps[index];
619
620 if (bp)
621 val = bp->hw.info.address;
622 } else if (n == 6) {
623 val = thread->virtual_dr6 ^ DR6_RESERVED; /* Flip back to arch polarity */
624 } else if (n == 7) {
625 val = thread->ptrace_dr7;
626 }
627 return val;
628}
629
630static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
631 unsigned long addr)
632{
633 struct thread_struct *t = &tsk->thread;
634 struct perf_event *bp = t->ptrace_bps[nr];
635 int err = 0;
636
637 if (!bp) {
638 /*
639 * Put stub len and type to create an inactive but correct bp.
640 *
641 * CHECKME: the previous code returned -EIO if the addr wasn't
642 * a valid task virtual addr. The new one will return -EINVAL in
643 * this case.
644 * -EINVAL may be what we want for in-kernel breakpoints users,
645 * but -EIO looks better for ptrace, since we refuse a register
646 * writing for the user. And anyway this is the previous
647 * behaviour.
648 */
649 bp = ptrace_register_breakpoint(tsk,
650 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
651 addr, true);
652 if (IS_ERR(bp))
653 err = PTR_ERR(bp);
654 else
655 t->ptrace_bps[nr] = bp;
656 } else {
657 struct perf_event_attr attr = bp->attr;
658
659 attr.bp_addr = addr;
660 err = modify_user_hw_breakpoint(bp, &attr);
661 }
662
663 return err;
664}
665
666/*
667 * Handle PTRACE_POKEUSR calls for the debug register area.
668 */
669static int ptrace_set_debugreg(struct task_struct *tsk, int n,
670 unsigned long val)
671{
672 struct thread_struct *thread = &tsk->thread;
673 /* There are no DR4 or DR5 registers */
674 int rc = -EIO;
675
676 if (n < HBP_NUM) {
677 rc = ptrace_set_breakpoint_addr(tsk, n, val);
678 } else if (n == 6) {
679 thread->virtual_dr6 = val ^ DR6_RESERVED; /* Flip to positive polarity */
680 rc = 0;
681 } else if (n == 7) {
682 rc = ptrace_write_dr7(tsk, val);
683 if (!rc)
684 thread->ptrace_dr7 = val;
685 }
686 return rc;
687}
688
689/*
690 * These access the current or another (stopped) task's io permission
691 * bitmap for debugging or core dump.
692 */
693static int ioperm_active(struct task_struct *target,
694 const struct user_regset *regset)
695{
696 struct io_bitmap *iobm = target->thread.io_bitmap;
697
698 return iobm ? DIV_ROUND_UP(iobm->max, regset->size) : 0;
699}
700
701static int ioperm_get(struct task_struct *target,
702 const struct user_regset *regset,
703 struct membuf to)
704{
705 struct io_bitmap *iobm = target->thread.io_bitmap;
706
707 if (!iobm)
708 return -ENXIO;
709
710 return membuf_write(&to, iobm->bitmap, IO_BITMAP_BYTES);
711}
712
713/*
714 * Called by kernel/ptrace.c when detaching..
715 *
716 * Make sure the single step bit is not set.
717 */
718void ptrace_disable(struct task_struct *child)
719{
720 user_disable_single_step(child);
721}
722
723#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
724static const struct user_regset_view user_x86_32_view; /* Initialized below. */
725#endif
726#ifdef CONFIG_X86_64
727static const struct user_regset_view user_x86_64_view; /* Initialized below. */
728#endif
729
730long 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#ifdef CONFIG_X86_64
737 /* This is native 64-bit ptrace() */
738 const struct user_regset_view *regset_view = &user_x86_64_view;
739#else
740 /* This is native 32-bit ptrace() */
741 const struct user_regset_view *regset_view = &user_x86_32_view;
742#endif
743
744 switch (request) {
745 /* read the word at location addr in the USER area. */
746 case PTRACE_PEEKUSR: {
747 unsigned long tmp;
748
749 ret = -EIO;
750 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
751 break;
752
753 tmp = 0; /* Default return condition */
754 if (addr < sizeof(struct user_regs_struct))
755 tmp = getreg(child, addr);
756 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
757 addr <= offsetof(struct user, u_debugreg[7])) {
758 addr -= offsetof(struct user, u_debugreg[0]);
759 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
760 }
761 ret = put_user(tmp, datap);
762 break;
763 }
764
765 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
766 ret = -EIO;
767 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
768 break;
769
770 if (addr < sizeof(struct user_regs_struct))
771 ret = putreg(child, addr, data);
772 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
773 addr <= offsetof(struct user, u_debugreg[7])) {
774 addr -= offsetof(struct user, u_debugreg[0]);
775 ret = ptrace_set_debugreg(child,
776 addr / sizeof(data), data);
777 }
778 break;
779
780 case PTRACE_GETREGS: /* Get all gp regs from the child. */
781 return copy_regset_to_user(child,
782 regset_view,
783 REGSET_GENERAL,
784 0, sizeof(struct user_regs_struct),
785 datap);
786
787 case PTRACE_SETREGS: /* Set all gp regs in the child. */
788 return copy_regset_from_user(child,
789 regset_view,
790 REGSET_GENERAL,
791 0, sizeof(struct user_regs_struct),
792 datap);
793
794 case PTRACE_GETFPREGS: /* Get the child FPU state. */
795 return copy_regset_to_user(child,
796 regset_view,
797 REGSET_FP,
798 0, sizeof(struct user_i387_struct),
799 datap);
800
801 case PTRACE_SETFPREGS: /* Set the child FPU state. */
802 return copy_regset_from_user(child,
803 regset_view,
804 REGSET_FP,
805 0, sizeof(struct user_i387_struct),
806 datap);
807
808#ifdef CONFIG_X86_32
809 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
810 return copy_regset_to_user(child, &user_x86_32_view,
811 REGSET32_XFP,
812 0, sizeof(struct user_fxsr_struct),
813 datap) ? -EIO : 0;
814
815 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
816 return copy_regset_from_user(child, &user_x86_32_view,
817 REGSET32_XFP,
818 0, sizeof(struct user_fxsr_struct),
819 datap) ? -EIO : 0;
820#endif
821
822#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
823 case PTRACE_GET_THREAD_AREA:
824 if ((int) addr < 0)
825 return -EIO;
826 ret = do_get_thread_area(child, addr,
827 (struct user_desc __user *)data);
828 break;
829
830 case PTRACE_SET_THREAD_AREA:
831 if ((int) addr < 0)
832 return -EIO;
833 ret = do_set_thread_area(child, addr,
834 (struct user_desc __user *)data, 0);
835 break;
836#endif
837
838#ifdef CONFIG_X86_64
839 /* normal 64bit interface to access TLS data.
840 Works just like arch_prctl, except that the arguments
841 are reversed. */
842 case PTRACE_ARCH_PRCTL:
843 ret = do_arch_prctl_64(child, data, addr);
844 break;
845#endif
846
847 default:
848 ret = ptrace_request(child, request, addr, data);
849 break;
850 }
851
852 return ret;
853}
854
855#ifdef CONFIG_IA32_EMULATION
856
857#include <linux/compat.h>
858#include <linux/syscalls.h>
859#include <asm/ia32.h>
860#include <asm/user32.h>
861
862#define R32(l,q) \
863 case offsetof(struct user32, regs.l): \
864 regs->q = value; break
865
866#define SEG32(rs) \
867 case offsetof(struct user32, regs.rs): \
868 return set_segment_reg(child, \
869 offsetof(struct user_regs_struct, rs), \
870 value); \
871 break
872
873static int putreg32(struct task_struct *child, unsigned regno, u32 value)
874{
875 struct pt_regs *regs = task_pt_regs(child);
876 int ret;
877
878 switch (regno) {
879
880 SEG32(cs);
881 SEG32(ds);
882 SEG32(es);
883
884 /*
885 * A 32-bit ptracer on a 64-bit kernel expects that writing
886 * FS or GS will also update the base. This is needed for
887 * operations like PTRACE_SETREGS to fully restore a saved
888 * CPU state.
889 */
890
891 case offsetof(struct user32, regs.fs):
892 ret = set_segment_reg(child,
893 offsetof(struct user_regs_struct, fs),
894 value);
895 if (ret == 0)
896 child->thread.fsbase =
897 x86_fsgsbase_read_task(child, value);
898 return ret;
899
900 case offsetof(struct user32, regs.gs):
901 ret = set_segment_reg(child,
902 offsetof(struct user_regs_struct, gs),
903 value);
904 if (ret == 0)
905 child->thread.gsbase =
906 x86_fsgsbase_read_task(child, value);
907 return ret;
908
909 SEG32(ss);
910
911 R32(ebx, bx);
912 R32(ecx, cx);
913 R32(edx, dx);
914 R32(edi, di);
915 R32(esi, si);
916 R32(ebp, bp);
917 R32(eax, ax);
918 R32(eip, ip);
919 R32(esp, sp);
920
921 case offsetof(struct user32, regs.orig_eax):
922 /*
923 * Warning: bizarre corner case fixup here. A 32-bit
924 * debugger setting orig_eax to -1 wants to disable
925 * syscall restart. Make sure that the syscall
926 * restart code sign-extends orig_ax. Also make sure
927 * we interpret the -ERESTART* codes correctly if
928 * loaded into regs->ax in case the task is not
929 * actually still sitting at the exit from a 32-bit
930 * syscall with TS_COMPAT still set.
931 */
932 regs->orig_ax = value;
933 if (syscall_get_nr(child, regs) != -1)
934 child->thread_info.status |= TS_I386_REGS_POKED;
935 break;
936
937 case offsetof(struct user32, regs.eflags):
938 return set_flags(child, value);
939
940 case offsetof(struct user32, u_debugreg[0]) ...
941 offsetof(struct user32, u_debugreg[7]):
942 regno -= offsetof(struct user32, u_debugreg[0]);
943 return ptrace_set_debugreg(child, regno / 4, value);
944
945 default:
946 if (regno > sizeof(struct user32) || (regno & 3))
947 return -EIO;
948
949 /*
950 * Other dummy fields in the virtual user structure
951 * are ignored
952 */
953 break;
954 }
955 return 0;
956}
957
958#undef R32
959#undef SEG32
960
961#define R32(l,q) \
962 case offsetof(struct user32, regs.l): \
963 *val = regs->q; break
964
965#define SEG32(rs) \
966 case offsetof(struct user32, regs.rs): \
967 *val = get_segment_reg(child, \
968 offsetof(struct user_regs_struct, rs)); \
969 break
970
971static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
972{
973 struct pt_regs *regs = task_pt_regs(child);
974
975 switch (regno) {
976
977 SEG32(ds);
978 SEG32(es);
979 SEG32(fs);
980 SEG32(gs);
981
982 R32(cs, cs);
983 R32(ss, ss);
984 R32(ebx, bx);
985 R32(ecx, cx);
986 R32(edx, dx);
987 R32(edi, di);
988 R32(esi, si);
989 R32(ebp, bp);
990 R32(eax, ax);
991 R32(orig_eax, orig_ax);
992 R32(eip, ip);
993 R32(esp, sp);
994
995 case offsetof(struct user32, regs.eflags):
996 *val = get_flags(child);
997 break;
998
999 case offsetof(struct user32, u_debugreg[0]) ...
1000 offsetof(struct user32, u_debugreg[7]):
1001 regno -= offsetof(struct user32, u_debugreg[0]);
1002 *val = ptrace_get_debugreg(child, regno / 4);
1003 break;
1004
1005 default:
1006 if (regno > sizeof(struct user32) || (regno & 3))
1007 return -EIO;
1008
1009 /*
1010 * Other dummy fields in the virtual user structure
1011 * are ignored
1012 */
1013 *val = 0;
1014 break;
1015 }
1016 return 0;
1017}
1018
1019#undef R32
1020#undef SEG32
1021
1022static int genregs32_get(struct task_struct *target,
1023 const struct user_regset *regset,
1024 struct membuf to)
1025{
1026 int reg;
1027
1028 for (reg = 0; to.left; reg++) {
1029 u32 val;
1030 getreg32(target, reg * 4, &val);
1031 membuf_store(&to, val);
1032 }
1033 return 0;
1034}
1035
1036static int genregs32_set(struct task_struct *target,
1037 const struct user_regset *regset,
1038 unsigned int pos, unsigned int count,
1039 const void *kbuf, const void __user *ubuf)
1040{
1041 int ret = 0;
1042 if (kbuf) {
1043 const compat_ulong_t *k = kbuf;
1044 while (count >= sizeof(*k) && !ret) {
1045 ret = putreg32(target, pos, *k++);
1046 count -= sizeof(*k);
1047 pos += sizeof(*k);
1048 }
1049 } else {
1050 const compat_ulong_t __user *u = ubuf;
1051 while (count >= sizeof(*u) && !ret) {
1052 compat_ulong_t word;
1053 ret = __get_user(word, u++);
1054 if (ret)
1055 break;
1056 ret = putreg32(target, pos, word);
1057 count -= sizeof(*u);
1058 pos += sizeof(*u);
1059 }
1060 }
1061 return ret;
1062}
1063
1064static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1065 compat_ulong_t caddr, compat_ulong_t cdata)
1066{
1067 unsigned long addr = caddr;
1068 unsigned long data = cdata;
1069 void __user *datap = compat_ptr(data);
1070 int ret;
1071 __u32 val;
1072
1073 switch (request) {
1074 case PTRACE_PEEKUSR:
1075 ret = getreg32(child, addr, &val);
1076 if (ret == 0)
1077 ret = put_user(val, (__u32 __user *)datap);
1078 break;
1079
1080 case PTRACE_POKEUSR:
1081 ret = putreg32(child, addr, data);
1082 break;
1083
1084 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1085 return copy_regset_to_user(child, &user_x86_32_view,
1086 REGSET_GENERAL,
1087 0, sizeof(struct user_regs_struct32),
1088 datap);
1089
1090 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1091 return copy_regset_from_user(child, &user_x86_32_view,
1092 REGSET_GENERAL, 0,
1093 sizeof(struct user_regs_struct32),
1094 datap);
1095
1096 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1097 return copy_regset_to_user(child, &user_x86_32_view,
1098 REGSET_FP, 0,
1099 sizeof(struct user_i387_ia32_struct),
1100 datap);
1101
1102 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1103 return copy_regset_from_user(
1104 child, &user_x86_32_view, REGSET_FP,
1105 0, sizeof(struct user_i387_ia32_struct), datap);
1106
1107 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1108 return copy_regset_to_user(child, &user_x86_32_view,
1109 REGSET32_XFP, 0,
1110 sizeof(struct user32_fxsr_struct),
1111 datap);
1112
1113 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1114 return copy_regset_from_user(child, &user_x86_32_view,
1115 REGSET32_XFP, 0,
1116 sizeof(struct user32_fxsr_struct),
1117 datap);
1118
1119 case PTRACE_GET_THREAD_AREA:
1120 case PTRACE_SET_THREAD_AREA:
1121 return arch_ptrace(child, request, addr, data);
1122
1123 default:
1124 return compat_ptrace_request(child, request, addr, data);
1125 }
1126
1127 return ret;
1128}
1129#endif /* CONFIG_IA32_EMULATION */
1130
1131#ifdef CONFIG_X86_X32_ABI
1132static long x32_arch_ptrace(struct task_struct *child,
1133 compat_long_t request, compat_ulong_t caddr,
1134 compat_ulong_t cdata)
1135{
1136 unsigned long addr = caddr;
1137 unsigned long data = cdata;
1138 void __user *datap = compat_ptr(data);
1139 int ret;
1140
1141 switch (request) {
1142 /* Read 32bits at location addr in the USER area. Only allow
1143 to return the lower 32bits of segment and debug registers. */
1144 case PTRACE_PEEKUSR: {
1145 u32 tmp;
1146
1147 ret = -EIO;
1148 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1149 addr < offsetof(struct user_regs_struct, cs))
1150 break;
1151
1152 tmp = 0; /* Default return condition */
1153 if (addr < sizeof(struct user_regs_struct))
1154 tmp = getreg(child, addr);
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 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1159 }
1160 ret = put_user(tmp, (__u32 __user *)datap);
1161 break;
1162 }
1163
1164 /* Write the word at location addr in the USER area. Only allow
1165 to update segment and debug registers with the upper 32bits
1166 zero-extended. */
1167 case PTRACE_POKEUSR:
1168 ret = -EIO;
1169 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1170 addr < offsetof(struct user_regs_struct, cs))
1171 break;
1172
1173 if (addr < sizeof(struct user_regs_struct))
1174 ret = putreg(child, addr, data);
1175 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1176 addr <= offsetof(struct user, u_debugreg[7])) {
1177 addr -= offsetof(struct user, u_debugreg[0]);
1178 ret = ptrace_set_debugreg(child,
1179 addr / sizeof(data), data);
1180 }
1181 break;
1182
1183 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1184 return copy_regset_to_user(child,
1185 &user_x86_64_view,
1186 REGSET_GENERAL,
1187 0, sizeof(struct user_regs_struct),
1188 datap);
1189
1190 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1191 return copy_regset_from_user(child,
1192 &user_x86_64_view,
1193 REGSET_GENERAL,
1194 0, sizeof(struct user_regs_struct),
1195 datap);
1196
1197 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1198 return copy_regset_to_user(child,
1199 &user_x86_64_view,
1200 REGSET_FP,
1201 0, sizeof(struct user_i387_struct),
1202 datap);
1203
1204 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1205 return copy_regset_from_user(child,
1206 &user_x86_64_view,
1207 REGSET_FP,
1208 0, sizeof(struct user_i387_struct),
1209 datap);
1210
1211 default:
1212 return compat_ptrace_request(child, request, addr, data);
1213 }
1214
1215 return ret;
1216}
1217#endif
1218
1219#ifdef CONFIG_COMPAT
1220long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1221 compat_ulong_t caddr, compat_ulong_t cdata)
1222{
1223#ifdef CONFIG_X86_X32_ABI
1224 if (!in_ia32_syscall())
1225 return x32_arch_ptrace(child, request, caddr, cdata);
1226#endif
1227#ifdef CONFIG_IA32_EMULATION
1228 return ia32_arch_ptrace(child, request, caddr, cdata);
1229#else
1230 return 0;
1231#endif
1232}
1233#endif /* CONFIG_COMPAT */
1234
1235#ifdef CONFIG_X86_64
1236
1237static struct user_regset x86_64_regsets[] __ro_after_init = {
1238 [REGSET64_GENERAL] = {
1239 .core_note_type = NT_PRSTATUS,
1240 .n = sizeof(struct user_regs_struct) / sizeof(long),
1241 .size = sizeof(long),
1242 .align = sizeof(long),
1243 .regset_get = genregs_get,
1244 .set = genregs_set
1245 },
1246 [REGSET64_FP] = {
1247 .core_note_type = NT_PRFPREG,
1248 .n = sizeof(struct fxregs_state) / sizeof(long),
1249 .size = sizeof(long),
1250 .align = sizeof(long),
1251 .active = regset_xregset_fpregs_active,
1252 .regset_get = xfpregs_get,
1253 .set = xfpregs_set
1254 },
1255 [REGSET64_XSTATE] = {
1256 .core_note_type = NT_X86_XSTATE,
1257 .size = sizeof(u64),
1258 .align = sizeof(u64),
1259 .active = xstateregs_active,
1260 .regset_get = xstateregs_get,
1261 .set = xstateregs_set
1262 },
1263 [REGSET64_IOPERM] = {
1264 .core_note_type = NT_386_IOPERM,
1265 .n = IO_BITMAP_LONGS,
1266 .size = sizeof(long),
1267 .align = sizeof(long),
1268 .active = ioperm_active,
1269 .regset_get = ioperm_get
1270 },
1271#ifdef CONFIG_X86_USER_SHADOW_STACK
1272 [REGSET64_SSP] = {
1273 .core_note_type = NT_X86_SHSTK,
1274 .n = 1,
1275 .size = sizeof(u64),
1276 .align = sizeof(u64),
1277 .active = ssp_active,
1278 .regset_get = ssp_get,
1279 .set = ssp_set
1280 },
1281#endif
1282};
1283
1284static const struct user_regset_view user_x86_64_view = {
1285 .name = "x86_64", .e_machine = EM_X86_64,
1286 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1287};
1288
1289#else /* CONFIG_X86_32 */
1290
1291#define user_regs_struct32 user_regs_struct
1292#define genregs32_get genregs_get
1293#define genregs32_set genregs_set
1294
1295#endif /* CONFIG_X86_64 */
1296
1297#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1298static struct user_regset x86_32_regsets[] __ro_after_init = {
1299 [REGSET32_GENERAL] = {
1300 .core_note_type = NT_PRSTATUS,
1301 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1302 .size = sizeof(u32),
1303 .align = sizeof(u32),
1304 .regset_get = genregs32_get,
1305 .set = genregs32_set
1306 },
1307 [REGSET32_FP] = {
1308 .core_note_type = NT_PRFPREG,
1309 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1310 .size = sizeof(u32),
1311 .align = sizeof(u32),
1312 .active = regset_fpregs_active,
1313 .regset_get = fpregs_get,
1314 .set = fpregs_set
1315 },
1316 [REGSET32_XFP] = {
1317 .core_note_type = NT_PRXFPREG,
1318 .n = sizeof(struct fxregs_state) / sizeof(u32),
1319 .size = sizeof(u32),
1320 .align = sizeof(u32),
1321 .active = regset_xregset_fpregs_active,
1322 .regset_get = xfpregs_get,
1323 .set = xfpregs_set
1324 },
1325 [REGSET32_XSTATE] = {
1326 .core_note_type = NT_X86_XSTATE,
1327 .size = sizeof(u64),
1328 .align = sizeof(u64),
1329 .active = xstateregs_active,
1330 .regset_get = xstateregs_get,
1331 .set = xstateregs_set
1332 },
1333 [REGSET32_TLS] = {
1334 .core_note_type = NT_386_TLS,
1335 .n = GDT_ENTRY_TLS_ENTRIES,
1336 .bias = GDT_ENTRY_TLS_MIN,
1337 .size = sizeof(struct user_desc),
1338 .align = sizeof(struct user_desc),
1339 .active = regset_tls_active,
1340 .regset_get = regset_tls_get,
1341 .set = regset_tls_set
1342 },
1343 [REGSET32_IOPERM] = {
1344 .core_note_type = NT_386_IOPERM,
1345 .n = IO_BITMAP_BYTES / sizeof(u32),
1346 .size = sizeof(u32),
1347 .align = sizeof(u32),
1348 .active = ioperm_active,
1349 .regset_get = ioperm_get
1350 },
1351};
1352
1353static const struct user_regset_view user_x86_32_view = {
1354 .name = "i386", .e_machine = EM_386,
1355 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1356};
1357#endif
1358
1359/*
1360 * This represents bytes 464..511 in the memory layout exported through
1361 * the REGSET_XSTATE interface.
1362 */
1363u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1364
1365void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1366{
1367#ifdef CONFIG_X86_64
1368 x86_64_regsets[REGSET64_XSTATE].n = size / sizeof(u64);
1369#endif
1370#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1371 x86_32_regsets[REGSET32_XSTATE].n = size / sizeof(u64);
1372#endif
1373 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1374}
1375
1376/*
1377 * This is used by the core dump code to decide which regset to dump. The
1378 * core dump code writes out the resulting .e_machine and the corresponding
1379 * regsets. This is suboptimal if the task is messing around with its CS.L
1380 * field, but at worst the core dump will end up missing some information.
1381 *
1382 * Unfortunately, it is also used by the broken PTRACE_GETREGSET and
1383 * PTRACE_SETREGSET APIs. These APIs look at the .regsets field but have
1384 * no way to make sure that the e_machine they use matches the caller's
1385 * expectations. The result is that the data format returned by
1386 * PTRACE_GETREGSET depends on the returned CS field (and even the offset
1387 * of the returned CS field depends on its value!) and the data format
1388 * accepted by PTRACE_SETREGSET is determined by the old CS value. The
1389 * upshot is that it is basically impossible to use these APIs correctly.
1390 *
1391 * The best way to fix it in the long run would probably be to add new
1392 * improved ptrace() APIs to read and write registers reliably, possibly by
1393 * allowing userspace to select the ELF e_machine variant that they expect.
1394 */
1395const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1396{
1397#ifdef CONFIG_IA32_EMULATION
1398 if (!user_64bit_mode(task_pt_regs(task)))
1399#endif
1400#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1401 return &user_x86_32_view;
1402#endif
1403#ifdef CONFIG_X86_64
1404 return &user_x86_64_view;
1405#endif
1406}
1407
1408void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1409{
1410 struct task_struct *tsk = current;
1411
1412 tsk->thread.trap_nr = X86_TRAP_DB;
1413 tsk->thread.error_code = error_code;
1414
1415 /* Send us the fake SIGTRAP */
1416 force_sig_fault(SIGTRAP, si_code,
1417 user_mode(regs) ? (void __user *)regs->ip : NULL);
1418}
1419
1420void user_single_step_report(struct pt_regs *regs)
1421{
1422 send_sigtrap(regs, 0, TRAP_BRKPT);
1423}