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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/processor.h>
32#include <asm/fpu/internal.h>
33#include <asm/fpu/signal.h>
34#include <asm/fpu/regset.h>
35#include <asm/debugreg.h>
36#include <asm/ldt.h>
37#include <asm/desc.h>
38#include <asm/prctl.h>
39#include <asm/proto.h>
40#include <asm/hw_breakpoint.h>
41#include <asm/traps.h>
42#include <asm/syscall.h>
43#include <asm/fsgsbase.h>
44#include <asm/io_bitmap.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 if (WARN_ON_ONCE(task == current))
185 return -EIO;
186
187 /*
188 * The value argument was already truncated to 16 bits.
189 */
190 if (invalid_selector(value))
191 return -EIO;
192
193 /*
194 * For %cs and %ss we cannot permit a null selector.
195 * We can permit a bogus selector as long as it has USER_RPL.
196 * Null selectors are fine for other segment registers, but
197 * we will never get back to user mode with invalid %cs or %ss
198 * and will take the trap in iret instead. Much code relies
199 * on user_mode() to distinguish a user trap frame (which can
200 * safely use invalid selectors) from a kernel trap frame.
201 */
202 switch (offset) {
203 case offsetof(struct user_regs_struct, cs):
204 case offsetof(struct user_regs_struct, ss):
205 if (unlikely(value == 0))
206 return -EIO;
207 fallthrough;
208
209 default:
210 *pt_regs_access(task_pt_regs(task), offset) = value;
211 break;
212
213 case offsetof(struct user_regs_struct, gs):
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 if (WARN_ON_ONCE(task == current))
275 return -EIO;
276
277 /*
278 * The value argument was already truncated to 16 bits.
279 */
280 if (invalid_selector(value))
281 return -EIO;
282
283 /*
284 * Writes to FS and GS will change the stored selector. Whether
285 * this changes the segment base as well depends on whether
286 * FSGSBASE is enabled.
287 */
288
289 switch (offset) {
290 case offsetof(struct user_regs_struct,fs):
291 task->thread.fsindex = value;
292 break;
293 case offsetof(struct user_regs_struct,gs):
294 task->thread.gsindex = value;
295 break;
296 case offsetof(struct user_regs_struct,ds):
297 task->thread.ds = value;
298 break;
299 case offsetof(struct user_regs_struct,es):
300 task->thread.es = value;
301 break;
302
303 /*
304 * Can't actually change these in 64-bit mode.
305 */
306 case offsetof(struct user_regs_struct,cs):
307 if (unlikely(value == 0))
308 return -EIO;
309 task_pt_regs(task)->cs = value;
310 break;
311 case offsetof(struct user_regs_struct,ss):
312 if (unlikely(value == 0))
313 return -EIO;
314 task_pt_regs(task)->ss = value;
315 break;
316 }
317
318 return 0;
319}
320
321#endif /* CONFIG_X86_32 */
322
323static unsigned long get_flags(struct task_struct *task)
324{
325 unsigned long retval = task_pt_regs(task)->flags;
326
327 /*
328 * If the debugger set TF, hide it from the readout.
329 */
330 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
331 retval &= ~X86_EFLAGS_TF;
332
333 return retval;
334}
335
336static int set_flags(struct task_struct *task, unsigned long value)
337{
338 struct pt_regs *regs = task_pt_regs(task);
339
340 /*
341 * If the user value contains TF, mark that
342 * it was not "us" (the debugger) that set it.
343 * If not, make sure it stays set if we had.
344 */
345 if (value & X86_EFLAGS_TF)
346 clear_tsk_thread_flag(task, TIF_FORCED_TF);
347 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
348 value |= X86_EFLAGS_TF;
349
350 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
351
352 return 0;
353}
354
355static int putreg(struct task_struct *child,
356 unsigned long offset, unsigned long value)
357{
358 switch (offset) {
359 case offsetof(struct user_regs_struct, cs):
360 case offsetof(struct user_regs_struct, ds):
361 case offsetof(struct user_regs_struct, es):
362 case offsetof(struct user_regs_struct, fs):
363 case offsetof(struct user_regs_struct, gs):
364 case offsetof(struct user_regs_struct, ss):
365 return set_segment_reg(child, offset, value);
366
367 case offsetof(struct user_regs_struct, flags):
368 return set_flags(child, value);
369
370#ifdef CONFIG_X86_64
371 case offsetof(struct user_regs_struct,fs_base):
372 if (value >= TASK_SIZE_MAX)
373 return -EIO;
374 x86_fsbase_write_task(child, value);
375 return 0;
376 case offsetof(struct user_regs_struct,gs_base):
377 if (value >= TASK_SIZE_MAX)
378 return -EIO;
379 x86_gsbase_write_task(child, value);
380 return 0;
381#endif
382 }
383
384 *pt_regs_access(task_pt_regs(child), offset) = value;
385 return 0;
386}
387
388static unsigned long getreg(struct task_struct *task, unsigned long offset)
389{
390 switch (offset) {
391 case offsetof(struct user_regs_struct, cs):
392 case offsetof(struct user_regs_struct, ds):
393 case offsetof(struct user_regs_struct, es):
394 case offsetof(struct user_regs_struct, fs):
395 case offsetof(struct user_regs_struct, gs):
396 case offsetof(struct user_regs_struct, ss):
397 return get_segment_reg(task, offset);
398
399 case offsetof(struct user_regs_struct, flags):
400 return get_flags(task);
401
402#ifdef CONFIG_X86_64
403 case offsetof(struct user_regs_struct, fs_base):
404 return x86_fsbase_read_task(task);
405 case offsetof(struct user_regs_struct, gs_base):
406 return x86_gsbase_read_task(task);
407#endif
408 }
409
410 return *pt_regs_access(task_pt_regs(task), offset);
411}
412
413static int genregs_get(struct task_struct *target,
414 const struct user_regset *regset,
415 struct membuf to)
416{
417 int reg;
418
419 for (reg = 0; to.left; reg++)
420 membuf_store(&to, getreg(target, reg * sizeof(unsigned long)));
421 return 0;
422}
423
424static int genregs_set(struct task_struct *target,
425 const struct user_regset *regset,
426 unsigned int pos, unsigned int count,
427 const void *kbuf, const void __user *ubuf)
428{
429 int ret = 0;
430 if (kbuf) {
431 const unsigned long *k = kbuf;
432 while (count >= sizeof(*k) && !ret) {
433 ret = putreg(target, pos, *k++);
434 count -= sizeof(*k);
435 pos += sizeof(*k);
436 }
437 } else {
438 const unsigned long __user *u = ubuf;
439 while (count >= sizeof(*u) && !ret) {
440 unsigned long word;
441 ret = __get_user(word, u++);
442 if (ret)
443 break;
444 ret = putreg(target, pos, word);
445 count -= sizeof(*u);
446 pos += sizeof(*u);
447 }
448 }
449 return ret;
450}
451
452static void ptrace_triggered(struct perf_event *bp,
453 struct perf_sample_data *data,
454 struct pt_regs *regs)
455{
456 int i;
457 struct thread_struct *thread = &(current->thread);
458
459 /*
460 * Store in the virtual DR6 register the fact that the breakpoint
461 * was hit so the thread's debugger will see it.
462 */
463 for (i = 0; i < HBP_NUM; i++) {
464 if (thread->ptrace_bps[i] == bp)
465 break;
466 }
467
468 thread->debugreg6 |= (DR_TRAP0 << i);
469}
470
471/*
472 * Walk through every ptrace breakpoints for this thread and
473 * build the dr7 value on top of their attributes.
474 *
475 */
476static unsigned long ptrace_get_dr7(struct perf_event *bp[])
477{
478 int i;
479 int dr7 = 0;
480 struct arch_hw_breakpoint *info;
481
482 for (i = 0; i < HBP_NUM; i++) {
483 if (bp[i] && !bp[i]->attr.disabled) {
484 info = counter_arch_bp(bp[i]);
485 dr7 |= encode_dr7(i, info->len, info->type);
486 }
487 }
488
489 return dr7;
490}
491
492static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
493 int len, int type, bool disabled)
494{
495 int err, bp_len, bp_type;
496
497 err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
498 if (!err) {
499 attr->bp_len = bp_len;
500 attr->bp_type = bp_type;
501 attr->disabled = disabled;
502 }
503
504 return err;
505}
506
507static struct perf_event *
508ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
509 unsigned long addr, bool disabled)
510{
511 struct perf_event_attr attr;
512 int err;
513
514 ptrace_breakpoint_init(&attr);
515 attr.bp_addr = addr;
516
517 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
518 if (err)
519 return ERR_PTR(err);
520
521 return register_user_hw_breakpoint(&attr, ptrace_triggered,
522 NULL, tsk);
523}
524
525static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
526 int disabled)
527{
528 struct perf_event_attr attr = bp->attr;
529 int err;
530
531 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
532 if (err)
533 return err;
534
535 return modify_user_hw_breakpoint(bp, &attr);
536}
537
538/*
539 * Handle ptrace writes to debug register 7.
540 */
541static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
542{
543 struct thread_struct *thread = &tsk->thread;
544 unsigned long old_dr7;
545 bool second_pass = false;
546 int i, rc, ret = 0;
547
548 data &= ~DR_CONTROL_RESERVED;
549 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
550
551restore:
552 rc = 0;
553 for (i = 0; i < HBP_NUM; i++) {
554 unsigned len, type;
555 bool disabled = !decode_dr7(data, i, &len, &type);
556 struct perf_event *bp = thread->ptrace_bps[i];
557
558 if (!bp) {
559 if (disabled)
560 continue;
561
562 bp = ptrace_register_breakpoint(tsk,
563 len, type, 0, disabled);
564 if (IS_ERR(bp)) {
565 rc = PTR_ERR(bp);
566 break;
567 }
568
569 thread->ptrace_bps[i] = bp;
570 continue;
571 }
572
573 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
574 if (rc)
575 break;
576 }
577
578 /* Restore if the first pass failed, second_pass shouldn't fail. */
579 if (rc && !WARN_ON(second_pass)) {
580 ret = rc;
581 data = old_dr7;
582 second_pass = true;
583 goto restore;
584 }
585
586 return ret;
587}
588
589/*
590 * Handle PTRACE_PEEKUSR calls for the debug register area.
591 */
592static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
593{
594 struct thread_struct *thread = &tsk->thread;
595 unsigned long val = 0;
596
597 if (n < HBP_NUM) {
598 int index = array_index_nospec(n, HBP_NUM);
599 struct perf_event *bp = thread->ptrace_bps[index];
600
601 if (bp)
602 val = bp->hw.info.address;
603 } else if (n == 6) {
604 val = thread->debugreg6;
605 } else if (n == 7) {
606 val = thread->ptrace_dr7;
607 }
608 return val;
609}
610
611static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
612 unsigned long addr)
613{
614 struct thread_struct *t = &tsk->thread;
615 struct perf_event *bp = t->ptrace_bps[nr];
616 int err = 0;
617
618 if (!bp) {
619 /*
620 * Put stub len and type to create an inactive but correct bp.
621 *
622 * CHECKME: the previous code returned -EIO if the addr wasn't
623 * a valid task virtual addr. The new one will return -EINVAL in
624 * this case.
625 * -EINVAL may be what we want for in-kernel breakpoints users,
626 * but -EIO looks better for ptrace, since we refuse a register
627 * writing for the user. And anyway this is the previous
628 * behaviour.
629 */
630 bp = ptrace_register_breakpoint(tsk,
631 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
632 addr, true);
633 if (IS_ERR(bp))
634 err = PTR_ERR(bp);
635 else
636 t->ptrace_bps[nr] = bp;
637 } else {
638 struct perf_event_attr attr = bp->attr;
639
640 attr.bp_addr = addr;
641 err = modify_user_hw_breakpoint(bp, &attr);
642 }
643
644 return err;
645}
646
647/*
648 * Handle PTRACE_POKEUSR calls for the debug register area.
649 */
650static int ptrace_set_debugreg(struct task_struct *tsk, int n,
651 unsigned long val)
652{
653 struct thread_struct *thread = &tsk->thread;
654 /* There are no DR4 or DR5 registers */
655 int rc = -EIO;
656
657 if (n < HBP_NUM) {
658 rc = ptrace_set_breakpoint_addr(tsk, n, val);
659 } else if (n == 6) {
660 thread->debugreg6 = val;
661 rc = 0;
662 } else if (n == 7) {
663 rc = ptrace_write_dr7(tsk, val);
664 if (!rc)
665 thread->ptrace_dr7 = val;
666 }
667 return rc;
668}
669
670/*
671 * These access the current or another (stopped) task's io permission
672 * bitmap for debugging or core dump.
673 */
674static int ioperm_active(struct task_struct *target,
675 const struct user_regset *regset)
676{
677 struct io_bitmap *iobm = target->thread.io_bitmap;
678
679 return iobm ? DIV_ROUND_UP(iobm->max, regset->size) : 0;
680}
681
682static int ioperm_get(struct task_struct *target,
683 const struct user_regset *regset,
684 struct membuf to)
685{
686 struct io_bitmap *iobm = target->thread.io_bitmap;
687
688 if (!iobm)
689 return -ENXIO;
690
691 return membuf_write(&to, iobm->bitmap, IO_BITMAP_BYTES);
692}
693
694/*
695 * Called by kernel/ptrace.c when detaching..
696 *
697 * Make sure the single step bit is not set.
698 */
699void ptrace_disable(struct task_struct *child)
700{
701 user_disable_single_step(child);
702}
703
704#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
705static const struct user_regset_view user_x86_32_view; /* Initialized below. */
706#endif
707
708long arch_ptrace(struct task_struct *child, long request,
709 unsigned long addr, unsigned long data)
710{
711 int ret;
712 unsigned long __user *datap = (unsigned long __user *)data;
713
714 switch (request) {
715 /* read the word at location addr in the USER area. */
716 case PTRACE_PEEKUSR: {
717 unsigned long tmp;
718
719 ret = -EIO;
720 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
721 break;
722
723 tmp = 0; /* Default return condition */
724 if (addr < sizeof(struct user_regs_struct))
725 tmp = getreg(child, addr);
726 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
727 addr <= offsetof(struct user, u_debugreg[7])) {
728 addr -= offsetof(struct user, u_debugreg[0]);
729 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
730 }
731 ret = put_user(tmp, datap);
732 break;
733 }
734
735 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
736 ret = -EIO;
737 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
738 break;
739
740 if (addr < sizeof(struct user_regs_struct))
741 ret = putreg(child, addr, data);
742 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
743 addr <= offsetof(struct user, u_debugreg[7])) {
744 addr -= offsetof(struct user, u_debugreg[0]);
745 ret = ptrace_set_debugreg(child,
746 addr / sizeof(data), data);
747 }
748 break;
749
750 case PTRACE_GETREGS: /* Get all gp regs from the child. */
751 return copy_regset_to_user(child,
752 task_user_regset_view(current),
753 REGSET_GENERAL,
754 0, sizeof(struct user_regs_struct),
755 datap);
756
757 case PTRACE_SETREGS: /* Set all gp regs in the child. */
758 return copy_regset_from_user(child,
759 task_user_regset_view(current),
760 REGSET_GENERAL,
761 0, sizeof(struct user_regs_struct),
762 datap);
763
764 case PTRACE_GETFPREGS: /* Get the child FPU state. */
765 return copy_regset_to_user(child,
766 task_user_regset_view(current),
767 REGSET_FP,
768 0, sizeof(struct user_i387_struct),
769 datap);
770
771 case PTRACE_SETFPREGS: /* Set the child FPU state. */
772 return copy_regset_from_user(child,
773 task_user_regset_view(current),
774 REGSET_FP,
775 0, sizeof(struct user_i387_struct),
776 datap);
777
778#ifdef CONFIG_X86_32
779 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
780 return copy_regset_to_user(child, &user_x86_32_view,
781 REGSET_XFP,
782 0, sizeof(struct user_fxsr_struct),
783 datap) ? -EIO : 0;
784
785 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
786 return copy_regset_from_user(child, &user_x86_32_view,
787 REGSET_XFP,
788 0, sizeof(struct user_fxsr_struct),
789 datap) ? -EIO : 0;
790#endif
791
792#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
793 case PTRACE_GET_THREAD_AREA:
794 if ((int) addr < 0)
795 return -EIO;
796 ret = do_get_thread_area(child, addr,
797 (struct user_desc __user *)data);
798 break;
799
800 case PTRACE_SET_THREAD_AREA:
801 if ((int) addr < 0)
802 return -EIO;
803 ret = do_set_thread_area(child, addr,
804 (struct user_desc __user *)data, 0);
805 break;
806#endif
807
808#ifdef CONFIG_X86_64
809 /* normal 64bit interface to access TLS data.
810 Works just like arch_prctl, except that the arguments
811 are reversed. */
812 case PTRACE_ARCH_PRCTL:
813 ret = do_arch_prctl_64(child, data, addr);
814 break;
815#endif
816
817 default:
818 ret = ptrace_request(child, request, addr, data);
819 break;
820 }
821
822 return ret;
823}
824
825#ifdef CONFIG_IA32_EMULATION
826
827#include <linux/compat.h>
828#include <linux/syscalls.h>
829#include <asm/ia32.h>
830#include <asm/user32.h>
831
832#define R32(l,q) \
833 case offsetof(struct user32, regs.l): \
834 regs->q = value; break
835
836#define SEG32(rs) \
837 case offsetof(struct user32, regs.rs): \
838 return set_segment_reg(child, \
839 offsetof(struct user_regs_struct, rs), \
840 value); \
841 break
842
843static int putreg32(struct task_struct *child, unsigned regno, u32 value)
844{
845 struct pt_regs *regs = task_pt_regs(child);
846 int ret;
847
848 switch (regno) {
849
850 SEG32(cs);
851 SEG32(ds);
852 SEG32(es);
853
854 /*
855 * A 32-bit ptracer on a 64-bit kernel expects that writing
856 * FS or GS will also update the base. This is needed for
857 * operations like PTRACE_SETREGS to fully restore a saved
858 * CPU state.
859 */
860
861 case offsetof(struct user32, regs.fs):
862 ret = set_segment_reg(child,
863 offsetof(struct user_regs_struct, fs),
864 value);
865 if (ret == 0)
866 child->thread.fsbase =
867 x86_fsgsbase_read_task(child, value);
868 return ret;
869
870 case offsetof(struct user32, regs.gs):
871 ret = set_segment_reg(child,
872 offsetof(struct user_regs_struct, gs),
873 value);
874 if (ret == 0)
875 child->thread.gsbase =
876 x86_fsgsbase_read_task(child, value);
877 return ret;
878
879 SEG32(ss);
880
881 R32(ebx, bx);
882 R32(ecx, cx);
883 R32(edx, dx);
884 R32(edi, di);
885 R32(esi, si);
886 R32(ebp, bp);
887 R32(eax, ax);
888 R32(eip, ip);
889 R32(esp, sp);
890
891 case offsetof(struct user32, regs.orig_eax):
892 /*
893 * Warning: bizarre corner case fixup here. A 32-bit
894 * debugger setting orig_eax to -1 wants to disable
895 * syscall restart. Make sure that the syscall
896 * restart code sign-extends orig_ax. Also make sure
897 * we interpret the -ERESTART* codes correctly if
898 * loaded into regs->ax in case the task is not
899 * actually still sitting at the exit from a 32-bit
900 * syscall with TS_COMPAT still set.
901 */
902 regs->orig_ax = value;
903 if (syscall_get_nr(child, regs) >= 0)
904 child->thread_info.status |= TS_I386_REGS_POKED;
905 break;
906
907 case offsetof(struct user32, regs.eflags):
908 return set_flags(child, value);
909
910 case offsetof(struct user32, u_debugreg[0]) ...
911 offsetof(struct user32, u_debugreg[7]):
912 regno -= offsetof(struct user32, u_debugreg[0]);
913 return ptrace_set_debugreg(child, regno / 4, value);
914
915 default:
916 if (regno > sizeof(struct user32) || (regno & 3))
917 return -EIO;
918
919 /*
920 * Other dummy fields in the virtual user structure
921 * are ignored
922 */
923 break;
924 }
925 return 0;
926}
927
928#undef R32
929#undef SEG32
930
931#define R32(l,q) \
932 case offsetof(struct user32, regs.l): \
933 *val = regs->q; break
934
935#define SEG32(rs) \
936 case offsetof(struct user32, regs.rs): \
937 *val = get_segment_reg(child, \
938 offsetof(struct user_regs_struct, rs)); \
939 break
940
941static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
942{
943 struct pt_regs *regs = task_pt_regs(child);
944
945 switch (regno) {
946
947 SEG32(ds);
948 SEG32(es);
949 SEG32(fs);
950 SEG32(gs);
951
952 R32(cs, cs);
953 R32(ss, ss);
954 R32(ebx, bx);
955 R32(ecx, cx);
956 R32(edx, dx);
957 R32(edi, di);
958 R32(esi, si);
959 R32(ebp, bp);
960 R32(eax, ax);
961 R32(orig_eax, orig_ax);
962 R32(eip, ip);
963 R32(esp, sp);
964
965 case offsetof(struct user32, regs.eflags):
966 *val = get_flags(child);
967 break;
968
969 case offsetof(struct user32, u_debugreg[0]) ...
970 offsetof(struct user32, u_debugreg[7]):
971 regno -= offsetof(struct user32, u_debugreg[0]);
972 *val = ptrace_get_debugreg(child, regno / 4);
973 break;
974
975 default:
976 if (regno > sizeof(struct user32) || (regno & 3))
977 return -EIO;
978
979 /*
980 * Other dummy fields in the virtual user structure
981 * are ignored
982 */
983 *val = 0;
984 break;
985 }
986 return 0;
987}
988
989#undef R32
990#undef SEG32
991
992static int genregs32_get(struct task_struct *target,
993 const struct user_regset *regset,
994 struct membuf to)
995{
996 int reg;
997
998 for (reg = 0; to.left; reg++) {
999 u32 val;
1000 getreg32(target, reg * 4, &val);
1001 membuf_store(&to, val);
1002 }
1003 return 0;
1004}
1005
1006static int genregs32_set(struct task_struct *target,
1007 const struct user_regset *regset,
1008 unsigned int pos, unsigned int count,
1009 const void *kbuf, const void __user *ubuf)
1010{
1011 int ret = 0;
1012 if (kbuf) {
1013 const compat_ulong_t *k = kbuf;
1014 while (count >= sizeof(*k) && !ret) {
1015 ret = putreg32(target, pos, *k++);
1016 count -= sizeof(*k);
1017 pos += sizeof(*k);
1018 }
1019 } else {
1020 const compat_ulong_t __user *u = ubuf;
1021 while (count >= sizeof(*u) && !ret) {
1022 compat_ulong_t word;
1023 ret = __get_user(word, u++);
1024 if (ret)
1025 break;
1026 ret = putreg32(target, pos, word);
1027 count -= sizeof(*u);
1028 pos += sizeof(*u);
1029 }
1030 }
1031 return ret;
1032}
1033
1034static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1035 compat_ulong_t caddr, compat_ulong_t cdata)
1036{
1037 unsigned long addr = caddr;
1038 unsigned long data = cdata;
1039 void __user *datap = compat_ptr(data);
1040 int ret;
1041 __u32 val;
1042
1043 switch (request) {
1044 case PTRACE_PEEKUSR:
1045 ret = getreg32(child, addr, &val);
1046 if (ret == 0)
1047 ret = put_user(val, (__u32 __user *)datap);
1048 break;
1049
1050 case PTRACE_POKEUSR:
1051 ret = putreg32(child, addr, data);
1052 break;
1053
1054 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1055 return copy_regset_to_user(child, &user_x86_32_view,
1056 REGSET_GENERAL,
1057 0, sizeof(struct user_regs_struct32),
1058 datap);
1059
1060 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1061 return copy_regset_from_user(child, &user_x86_32_view,
1062 REGSET_GENERAL, 0,
1063 sizeof(struct user_regs_struct32),
1064 datap);
1065
1066 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1067 return copy_regset_to_user(child, &user_x86_32_view,
1068 REGSET_FP, 0,
1069 sizeof(struct user_i387_ia32_struct),
1070 datap);
1071
1072 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1073 return copy_regset_from_user(
1074 child, &user_x86_32_view, REGSET_FP,
1075 0, sizeof(struct user_i387_ia32_struct), datap);
1076
1077 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1078 return copy_regset_to_user(child, &user_x86_32_view,
1079 REGSET_XFP, 0,
1080 sizeof(struct user32_fxsr_struct),
1081 datap);
1082
1083 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1084 return copy_regset_from_user(child, &user_x86_32_view,
1085 REGSET_XFP, 0,
1086 sizeof(struct user32_fxsr_struct),
1087 datap);
1088
1089 case PTRACE_GET_THREAD_AREA:
1090 case PTRACE_SET_THREAD_AREA:
1091 return arch_ptrace(child, request, addr, data);
1092
1093 default:
1094 return compat_ptrace_request(child, request, addr, data);
1095 }
1096
1097 return ret;
1098}
1099#endif /* CONFIG_IA32_EMULATION */
1100
1101#ifdef CONFIG_X86_X32_ABI
1102static long x32_arch_ptrace(struct task_struct *child,
1103 compat_long_t request, compat_ulong_t caddr,
1104 compat_ulong_t cdata)
1105{
1106 unsigned long addr = caddr;
1107 unsigned long data = cdata;
1108 void __user *datap = compat_ptr(data);
1109 int ret;
1110
1111 switch (request) {
1112 /* Read 32bits at location addr in the USER area. Only allow
1113 to return the lower 32bits of segment and debug registers. */
1114 case PTRACE_PEEKUSR: {
1115 u32 tmp;
1116
1117 ret = -EIO;
1118 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1119 addr < offsetof(struct user_regs_struct, cs))
1120 break;
1121
1122 tmp = 0; /* Default return condition */
1123 if (addr < sizeof(struct user_regs_struct))
1124 tmp = getreg(child, addr);
1125 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1126 addr <= offsetof(struct user, u_debugreg[7])) {
1127 addr -= offsetof(struct user, u_debugreg[0]);
1128 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1129 }
1130 ret = put_user(tmp, (__u32 __user *)datap);
1131 break;
1132 }
1133
1134 /* Write the word at location addr in the USER area. Only allow
1135 to update segment and debug registers with the upper 32bits
1136 zero-extended. */
1137 case PTRACE_POKEUSR:
1138 ret = -EIO;
1139 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1140 addr < offsetof(struct user_regs_struct, cs))
1141 break;
1142
1143 if (addr < sizeof(struct user_regs_struct))
1144 ret = putreg(child, addr, data);
1145 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1146 addr <= offsetof(struct user, u_debugreg[7])) {
1147 addr -= offsetof(struct user, u_debugreg[0]);
1148 ret = ptrace_set_debugreg(child,
1149 addr / sizeof(data), data);
1150 }
1151 break;
1152
1153 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1154 return copy_regset_to_user(child,
1155 task_user_regset_view(current),
1156 REGSET_GENERAL,
1157 0, sizeof(struct user_regs_struct),
1158 datap);
1159
1160 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1161 return copy_regset_from_user(child,
1162 task_user_regset_view(current),
1163 REGSET_GENERAL,
1164 0, sizeof(struct user_regs_struct),
1165 datap);
1166
1167 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1168 return copy_regset_to_user(child,
1169 task_user_regset_view(current),
1170 REGSET_FP,
1171 0, sizeof(struct user_i387_struct),
1172 datap);
1173
1174 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1175 return copy_regset_from_user(child,
1176 task_user_regset_view(current),
1177 REGSET_FP,
1178 0, sizeof(struct user_i387_struct),
1179 datap);
1180
1181 default:
1182 return compat_ptrace_request(child, request, addr, data);
1183 }
1184
1185 return ret;
1186}
1187#endif
1188
1189#ifdef CONFIG_COMPAT
1190long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1191 compat_ulong_t caddr, compat_ulong_t cdata)
1192{
1193#ifdef CONFIG_X86_X32_ABI
1194 if (!in_ia32_syscall())
1195 return x32_arch_ptrace(child, request, caddr, cdata);
1196#endif
1197#ifdef CONFIG_IA32_EMULATION
1198 return ia32_arch_ptrace(child, request, caddr, cdata);
1199#else
1200 return 0;
1201#endif
1202}
1203#endif /* CONFIG_COMPAT */
1204
1205#ifdef CONFIG_X86_64
1206
1207static struct user_regset x86_64_regsets[] __ro_after_init = {
1208 [REGSET_GENERAL] = {
1209 .core_note_type = NT_PRSTATUS,
1210 .n = sizeof(struct user_regs_struct) / sizeof(long),
1211 .size = sizeof(long), .align = sizeof(long),
1212 .regset_get = genregs_get, .set = genregs_set
1213 },
1214 [REGSET_FP] = {
1215 .core_note_type = NT_PRFPREG,
1216 .n = sizeof(struct user_i387_struct) / sizeof(long),
1217 .size = sizeof(long), .align = sizeof(long),
1218 .active = regset_xregset_fpregs_active, .regset_get = xfpregs_get, .set = xfpregs_set
1219 },
1220 [REGSET_XSTATE] = {
1221 .core_note_type = NT_X86_XSTATE,
1222 .size = sizeof(u64), .align = sizeof(u64),
1223 .active = xstateregs_active, .regset_get = xstateregs_get,
1224 .set = xstateregs_set
1225 },
1226 [REGSET_IOPERM64] = {
1227 .core_note_type = NT_386_IOPERM,
1228 .n = IO_BITMAP_LONGS,
1229 .size = sizeof(long), .align = sizeof(long),
1230 .active = ioperm_active, .regset_get = ioperm_get
1231 },
1232};
1233
1234static const struct user_regset_view user_x86_64_view = {
1235 .name = "x86_64", .e_machine = EM_X86_64,
1236 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1237};
1238
1239#else /* CONFIG_X86_32 */
1240
1241#define user_regs_struct32 user_regs_struct
1242#define genregs32_get genregs_get
1243#define genregs32_set genregs_set
1244
1245#endif /* CONFIG_X86_64 */
1246
1247#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1248static struct user_regset x86_32_regsets[] __ro_after_init = {
1249 [REGSET_GENERAL] = {
1250 .core_note_type = NT_PRSTATUS,
1251 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1252 .size = sizeof(u32), .align = sizeof(u32),
1253 .regset_get = genregs32_get, .set = genregs32_set
1254 },
1255 [REGSET_FP] = {
1256 .core_note_type = NT_PRFPREG,
1257 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1258 .size = sizeof(u32), .align = sizeof(u32),
1259 .active = regset_fpregs_active, .regset_get = fpregs_get, .set = fpregs_set
1260 },
1261 [REGSET_XFP] = {
1262 .core_note_type = NT_PRXFPREG,
1263 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1264 .size = sizeof(u32), .align = sizeof(u32),
1265 .active = regset_xregset_fpregs_active, .regset_get = xfpregs_get, .set = xfpregs_set
1266 },
1267 [REGSET_XSTATE] = {
1268 .core_note_type = NT_X86_XSTATE,
1269 .size = sizeof(u64), .align = sizeof(u64),
1270 .active = xstateregs_active, .regset_get = xstateregs_get,
1271 .set = xstateregs_set
1272 },
1273 [REGSET_TLS] = {
1274 .core_note_type = NT_386_TLS,
1275 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1276 .size = sizeof(struct user_desc),
1277 .align = sizeof(struct user_desc),
1278 .active = regset_tls_active,
1279 .regset_get = regset_tls_get, .set = regset_tls_set
1280 },
1281 [REGSET_IOPERM32] = {
1282 .core_note_type = NT_386_IOPERM,
1283 .n = IO_BITMAP_BYTES / sizeof(u32),
1284 .size = sizeof(u32), .align = sizeof(u32),
1285 .active = ioperm_active, .regset_get = ioperm_get
1286 },
1287};
1288
1289static const struct user_regset_view user_x86_32_view = {
1290 .name = "i386", .e_machine = EM_386,
1291 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1292};
1293#endif
1294
1295/*
1296 * This represents bytes 464..511 in the memory layout exported through
1297 * the REGSET_XSTATE interface.
1298 */
1299u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1300
1301void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1302{
1303#ifdef CONFIG_X86_64
1304 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1305#endif
1306#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1307 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1308#endif
1309 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1310}
1311
1312const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1313{
1314#ifdef CONFIG_IA32_EMULATION
1315 if (!user_64bit_mode(task_pt_regs(task)))
1316#endif
1317#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1318 return &user_x86_32_view;
1319#endif
1320#ifdef CONFIG_X86_64
1321 return &user_x86_64_view;
1322#endif
1323}
1324
1325void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1326{
1327 struct task_struct *tsk = current;
1328
1329 tsk->thread.trap_nr = X86_TRAP_DB;
1330 tsk->thread.error_code = error_code;
1331
1332 /* Send us the fake SIGTRAP */
1333 force_sig_fault(SIGTRAP, si_code,
1334 user_mode(regs) ? (void __user *)regs->ip : NULL);
1335}
1336
1337void user_single_step_report(struct pt_regs *regs)
1338{
1339 send_sigtrap(regs, 0, TRAP_BRKPT);
1340}
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}