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[platform/kernel/linux-rpi.git] / arch / x86 / kernel / ptrace.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* By Ross Biro 1/23/92 */
3 /*
4  * Pentium III FXSR, SSE support
5  *      Gareth Hughes <gareth@valinux.com>, May 2000
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/sched.h>
10 #include <linux/sched/task_stack.h>
11 #include <linux/mm.h>
12 #include <linux/smp.h>
13 #include <linux/errno.h>
14 #include <linux/slab.h>
15 #include <linux/ptrace.h>
16 #include <linux/tracehook.h>
17 #include <linux/user.h>
18 #include <linux/elf.h>
19 #include <linux/security.h>
20 #include <linux/audit.h>
21 #include <linux/seccomp.h>
22 #include <linux/signal.h>
23 #include <linux/perf_event.h>
24 #include <linux/hw_breakpoint.h>
25 #include <linux/rcupdate.h>
26 #include <linux/export.h>
27 #include <linux/context_tracking.h>
28 #include <linux/nospec.h>
29
30 #include <linux/uaccess.h>
31 #include <asm/pgtable.h>
32 #include <asm/processor.h>
33 #include <asm/fpu/internal.h>
34 #include <asm/fpu/signal.h>
35 #include <asm/fpu/regset.h>
36 #include <asm/debugreg.h>
37 #include <asm/ldt.h>
38 #include <asm/desc.h>
39 #include <asm/prctl.h>
40 #include <asm/proto.h>
41 #include <asm/hw_breakpoint.h>
42 #include <asm/traps.h>
43 #include <asm/syscall.h>
44 #include <asm/fsgsbase.h>
45
46 #include "tls.h"
47
48 enum x86_regset {
49         REGSET_GENERAL,
50         REGSET_FP,
51         REGSET_XFP,
52         REGSET_IOPERM64 = REGSET_XFP,
53         REGSET_XSTATE,
54         REGSET_TLS,
55         REGSET_IOPERM32,
56 };
57
58 struct pt_regs_offset {
59         const char *name;
60         int offset;
61 };
62
63 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
64 #define REG_OFFSET_END {.name = NULL, .offset = 0}
65
66 static const struct pt_regs_offset regoffset_table[] = {
67 #ifdef CONFIG_X86_64
68         REG_OFFSET_NAME(r15),
69         REG_OFFSET_NAME(r14),
70         REG_OFFSET_NAME(r13),
71         REG_OFFSET_NAME(r12),
72         REG_OFFSET_NAME(r11),
73         REG_OFFSET_NAME(r10),
74         REG_OFFSET_NAME(r9),
75         REG_OFFSET_NAME(r8),
76 #endif
77         REG_OFFSET_NAME(bx),
78         REG_OFFSET_NAME(cx),
79         REG_OFFSET_NAME(dx),
80         REG_OFFSET_NAME(si),
81         REG_OFFSET_NAME(di),
82         REG_OFFSET_NAME(bp),
83         REG_OFFSET_NAME(ax),
84 #ifdef CONFIG_X86_32
85         REG_OFFSET_NAME(ds),
86         REG_OFFSET_NAME(es),
87         REG_OFFSET_NAME(fs),
88         REG_OFFSET_NAME(gs),
89 #endif
90         REG_OFFSET_NAME(orig_ax),
91         REG_OFFSET_NAME(ip),
92         REG_OFFSET_NAME(cs),
93         REG_OFFSET_NAME(flags),
94         REG_OFFSET_NAME(sp),
95         REG_OFFSET_NAME(ss),
96         REG_OFFSET_END,
97 };
98
99 /**
100  * regs_query_register_offset() - query register offset from its name
101  * @name:       the name of a register
102  *
103  * regs_query_register_offset() returns the offset of a register in struct
104  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
105  */
106 int regs_query_register_offset(const char *name)
107 {
108         const struct pt_regs_offset *roff;
109         for (roff = regoffset_table; roff->name != NULL; roff++)
110                 if (!strcmp(roff->name, name))
111                         return roff->offset;
112         return -EINVAL;
113 }
114
115 /**
116  * regs_query_register_name() - query register name from its offset
117  * @offset:     the offset of a register in struct pt_regs.
118  *
119  * regs_query_register_name() returns the name of a register from its
120  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
121  */
122 const char *regs_query_register_name(unsigned int offset)
123 {
124         const struct pt_regs_offset *roff;
125         for (roff = regoffset_table; roff->name != NULL; roff++)
126                 if (roff->offset == offset)
127                         return roff->name;
128         return NULL;
129 }
130
131 /*
132  * does not yet catch signals sent when the child dies.
133  * in exit.c or in signal.c.
134  */
135
136 /*
137  * Determines which flags the user has access to [1 = access, 0 = no access].
138  */
139 #define FLAG_MASK_32            ((unsigned long)                        \
140                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
141                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
142                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
143                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
144                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
145
146 /*
147  * Determines whether a value may be installed in a segment register.
148  */
149 static inline bool invalid_selector(u16 value)
150 {
151         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
152 }
153
154 #ifdef CONFIG_X86_32
155
156 #define FLAG_MASK               FLAG_MASK_32
157
158 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
159 {
160         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
161         return &regs->bx + (regno >> 2);
162 }
163
164 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
165 {
166         /*
167          * Returning the value truncates it to 16 bits.
168          */
169         unsigned int retval;
170         if (offset != offsetof(struct user_regs_struct, gs))
171                 retval = *pt_regs_access(task_pt_regs(task), offset);
172         else {
173                 if (task == current)
174                         retval = get_user_gs(task_pt_regs(task));
175                 else
176                         retval = task_user_gs(task);
177         }
178         return retval;
179 }
180
181 static int set_segment_reg(struct task_struct *task,
182                            unsigned long offset, u16 value)
183 {
184         /*
185          * The value argument was already truncated to 16 bits.
186          */
187         if (invalid_selector(value))
188                 return -EIO;
189
190         /*
191          * For %cs and %ss we cannot permit a null selector.
192          * We can permit a bogus selector as long as it has USER_RPL.
193          * Null selectors are fine for other segment registers, but
194          * we will never get back to user mode with invalid %cs or %ss
195          * and will take the trap in iret instead.  Much code relies
196          * on user_mode() to distinguish a user trap frame (which can
197          * safely use invalid selectors) from a kernel trap frame.
198          */
199         switch (offset) {
200         case offsetof(struct user_regs_struct, cs):
201         case offsetof(struct user_regs_struct, ss):
202                 if (unlikely(value == 0))
203                         return -EIO;
204
205         default:
206                 *pt_regs_access(task_pt_regs(task), offset) = value;
207                 break;
208
209         case offsetof(struct user_regs_struct, gs):
210                 if (task == current)
211                         set_user_gs(task_pt_regs(task), value);
212                 else
213                         task_user_gs(task) = value;
214         }
215
216         return 0;
217 }
218
219 #else  /* CONFIG_X86_64 */
220
221 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
222
223 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
224 {
225         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
226         return &regs->r15 + (offset / sizeof(regs->r15));
227 }
228
229 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
230 {
231         /*
232          * Returning the value truncates it to 16 bits.
233          */
234         unsigned int seg;
235
236         switch (offset) {
237         case offsetof(struct user_regs_struct, fs):
238                 if (task == current) {
239                         /* Older gas can't assemble movq %?s,%r?? */
240                         asm("movl %%fs,%0" : "=r" (seg));
241                         return seg;
242                 }
243                 return task->thread.fsindex;
244         case offsetof(struct user_regs_struct, gs):
245                 if (task == current) {
246                         asm("movl %%gs,%0" : "=r" (seg));
247                         return seg;
248                 }
249                 return task->thread.gsindex;
250         case offsetof(struct user_regs_struct, ds):
251                 if (task == current) {
252                         asm("movl %%ds,%0" : "=r" (seg));
253                         return seg;
254                 }
255                 return task->thread.ds;
256         case offsetof(struct user_regs_struct, es):
257                 if (task == current) {
258                         asm("movl %%es,%0" : "=r" (seg));
259                         return seg;
260                 }
261                 return task->thread.es;
262
263         case offsetof(struct user_regs_struct, cs):
264         case offsetof(struct user_regs_struct, ss):
265                 break;
266         }
267         return *pt_regs_access(task_pt_regs(task), offset);
268 }
269
270 static int set_segment_reg(struct task_struct *task,
271                            unsigned long offset, u16 value)
272 {
273         /*
274          * The value argument was already truncated to 16 bits.
275          */
276         if (invalid_selector(value))
277                 return -EIO;
278
279         switch (offset) {
280         case offsetof(struct user_regs_struct,fs):
281                 task->thread.fsindex = value;
282                 if (task == current)
283                         loadsegment(fs, task->thread.fsindex);
284                 break;
285         case offsetof(struct user_regs_struct,gs):
286                 task->thread.gsindex = value;
287                 if (task == current)
288                         load_gs_index(task->thread.gsindex);
289                 break;
290         case offsetof(struct user_regs_struct,ds):
291                 task->thread.ds = value;
292                 if (task == current)
293                         loadsegment(ds, task->thread.ds);
294                 break;
295         case offsetof(struct user_regs_struct,es):
296                 task->thread.es = value;
297                 if (task == current)
298                         loadsegment(es, task->thread.es);
299                 break;
300
301                 /*
302                  * Can't actually change these in 64-bit mode.
303                  */
304         case offsetof(struct user_regs_struct,cs):
305                 if (unlikely(value == 0))
306                         return -EIO;
307                 task_pt_regs(task)->cs = value;
308                 break;
309         case offsetof(struct user_regs_struct,ss):
310                 if (unlikely(value == 0))
311                         return -EIO;
312                 task_pt_regs(task)->ss = value;
313                 break;
314         }
315
316         return 0;
317 }
318
319 #endif  /* CONFIG_X86_32 */
320
321 static unsigned long get_flags(struct task_struct *task)
322 {
323         unsigned long retval = task_pt_regs(task)->flags;
324
325         /*
326          * If the debugger set TF, hide it from the readout.
327          */
328         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
329                 retval &= ~X86_EFLAGS_TF;
330
331         return retval;
332 }
333
334 static int set_flags(struct task_struct *task, unsigned long value)
335 {
336         struct pt_regs *regs = task_pt_regs(task);
337
338         /*
339          * If the user value contains TF, mark that
340          * it was not "us" (the debugger) that set it.
341          * If not, make sure it stays set if we had.
342          */
343         if (value & X86_EFLAGS_TF)
344                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
345         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
346                 value |= X86_EFLAGS_TF;
347
348         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
349
350         return 0;
351 }
352
353 static int putreg(struct task_struct *child,
354                   unsigned long offset, unsigned long value)
355 {
356         switch (offset) {
357         case offsetof(struct user_regs_struct, cs):
358         case offsetof(struct user_regs_struct, ds):
359         case offsetof(struct user_regs_struct, es):
360         case offsetof(struct user_regs_struct, fs):
361         case offsetof(struct user_regs_struct, gs):
362         case offsetof(struct user_regs_struct, ss):
363                 return set_segment_reg(child, offset, value);
364
365         case offsetof(struct user_regs_struct, flags):
366                 return set_flags(child, value);
367
368 #ifdef CONFIG_X86_64
369         case offsetof(struct user_regs_struct,fs_base):
370                 if (value >= TASK_SIZE_MAX)
371                         return -EIO;
372                 x86_fsbase_write_task(child, value);
373                 return 0;
374         case offsetof(struct user_regs_struct,gs_base):
375                 if (value >= TASK_SIZE_MAX)
376                         return -EIO;
377                 x86_gsbase_write_task(child, value);
378                 return 0;
379 #endif
380         }
381
382         *pt_regs_access(task_pt_regs(child), offset) = value;
383         return 0;
384 }
385
386 static unsigned long getreg(struct task_struct *task, unsigned long offset)
387 {
388         switch (offset) {
389         case offsetof(struct user_regs_struct, cs):
390         case offsetof(struct user_regs_struct, ds):
391         case offsetof(struct user_regs_struct, es):
392         case offsetof(struct user_regs_struct, fs):
393         case offsetof(struct user_regs_struct, gs):
394         case offsetof(struct user_regs_struct, ss):
395                 return get_segment_reg(task, offset);
396
397         case offsetof(struct user_regs_struct, flags):
398                 return get_flags(task);
399
400 #ifdef CONFIG_X86_64
401         case offsetof(struct user_regs_struct, fs_base):
402                 return x86_fsbase_read_task(task);
403         case offsetof(struct user_regs_struct, gs_base):
404                 return x86_gsbase_read_task(task);
405 #endif
406         }
407
408         return *pt_regs_access(task_pt_regs(task), offset);
409 }
410
411 static int genregs_get(struct task_struct *target,
412                        const struct user_regset *regset,
413                        unsigned int pos, unsigned int count,
414                        void *kbuf, void __user *ubuf)
415 {
416         if (kbuf) {
417                 unsigned long *k = kbuf;
418                 while (count >= sizeof(*k)) {
419                         *k++ = getreg(target, pos);
420                         count -= sizeof(*k);
421                         pos += sizeof(*k);
422                 }
423         } else {
424                 unsigned long __user *u = ubuf;
425                 while (count >= sizeof(*u)) {
426                         if (__put_user(getreg(target, pos), u++))
427                                 return -EFAULT;
428                         count -= sizeof(*u);
429                         pos += sizeof(*u);
430                 }
431         }
432
433         return 0;
434 }
435
436 static int genregs_set(struct task_struct *target,
437                        const struct user_regset *regset,
438                        unsigned int pos, unsigned int count,
439                        const void *kbuf, const void __user *ubuf)
440 {
441         int ret = 0;
442         if (kbuf) {
443                 const unsigned long *k = kbuf;
444                 while (count >= sizeof(*k) && !ret) {
445                         ret = putreg(target, pos, *k++);
446                         count -= sizeof(*k);
447                         pos += sizeof(*k);
448                 }
449         } else {
450                 const unsigned long  __user *u = ubuf;
451                 while (count >= sizeof(*u) && !ret) {
452                         unsigned long word;
453                         ret = __get_user(word, u++);
454                         if (ret)
455                                 break;
456                         ret = putreg(target, pos, word);
457                         count -= sizeof(*u);
458                         pos += sizeof(*u);
459                 }
460         }
461         return ret;
462 }
463
464 static void ptrace_triggered(struct perf_event *bp,
465                              struct perf_sample_data *data,
466                              struct pt_regs *regs)
467 {
468         int i;
469         struct thread_struct *thread = &(current->thread);
470
471         /*
472          * Store in the virtual DR6 register the fact that the breakpoint
473          * was hit so the thread's debugger will see it.
474          */
475         for (i = 0; i < HBP_NUM; i++) {
476                 if (thread->ptrace_bps[i] == bp)
477                         break;
478         }
479
480         thread->debugreg6 |= (DR_TRAP0 << i);
481 }
482
483 /*
484  * Walk through every ptrace breakpoints for this thread and
485  * build the dr7 value on top of their attributes.
486  *
487  */
488 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
489 {
490         int i;
491         int dr7 = 0;
492         struct arch_hw_breakpoint *info;
493
494         for (i = 0; i < HBP_NUM; i++) {
495                 if (bp[i] && !bp[i]->attr.disabled) {
496                         info = counter_arch_bp(bp[i]);
497                         dr7 |= encode_dr7(i, info->len, info->type);
498                 }
499         }
500
501         return dr7;
502 }
503
504 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
505                                         int len, int type, bool disabled)
506 {
507         int err, bp_len, bp_type;
508
509         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
510         if (!err) {
511                 attr->bp_len = bp_len;
512                 attr->bp_type = bp_type;
513                 attr->disabled = disabled;
514         }
515
516         return err;
517 }
518
519 static struct perf_event *
520 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
521                                 unsigned long addr, bool disabled)
522 {
523         struct perf_event_attr attr;
524         int err;
525
526         ptrace_breakpoint_init(&attr);
527         attr.bp_addr = addr;
528
529         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
530         if (err)
531                 return ERR_PTR(err);
532
533         return register_user_hw_breakpoint(&attr, ptrace_triggered,
534                                                  NULL, tsk);
535 }
536
537 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
538                                         int disabled)
539 {
540         struct perf_event_attr attr = bp->attr;
541         int err;
542
543         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
544         if (err)
545                 return err;
546
547         return modify_user_hw_breakpoint(bp, &attr);
548 }
549
550 /*
551  * Handle ptrace writes to debug register 7.
552  */
553 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
554 {
555         struct thread_struct *thread = &tsk->thread;
556         unsigned long old_dr7;
557         bool second_pass = false;
558         int i, rc, ret = 0;
559
560         data &= ~DR_CONTROL_RESERVED;
561         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
562
563 restore:
564         rc = 0;
565         for (i = 0; i < HBP_NUM; i++) {
566                 unsigned len, type;
567                 bool disabled = !decode_dr7(data, i, &len, &type);
568                 struct perf_event *bp = thread->ptrace_bps[i];
569
570                 if (!bp) {
571                         if (disabled)
572                                 continue;
573
574                         bp = ptrace_register_breakpoint(tsk,
575                                         len, type, 0, disabled);
576                         if (IS_ERR(bp)) {
577                                 rc = PTR_ERR(bp);
578                                 break;
579                         }
580
581                         thread->ptrace_bps[i] = bp;
582                         continue;
583                 }
584
585                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
586                 if (rc)
587                         break;
588         }
589
590         /* Restore if the first pass failed, second_pass shouldn't fail. */
591         if (rc && !WARN_ON(second_pass)) {
592                 ret = rc;
593                 data = old_dr7;
594                 second_pass = true;
595                 goto restore;
596         }
597
598         return ret;
599 }
600
601 /*
602  * Handle PTRACE_PEEKUSR calls for the debug register area.
603  */
604 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
605 {
606         struct thread_struct *thread = &tsk->thread;
607         unsigned long val = 0;
608
609         if (n < HBP_NUM) {
610                 int index = array_index_nospec(n, HBP_NUM);
611                 struct perf_event *bp = thread->ptrace_bps[index];
612
613                 if (bp)
614                         val = bp->hw.info.address;
615         } else if (n == 6) {
616                 val = thread->debugreg6;
617         } else if (n == 7) {
618                 val = thread->ptrace_dr7;
619         }
620         return val;
621 }
622
623 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
624                                       unsigned long addr)
625 {
626         struct thread_struct *t = &tsk->thread;
627         struct perf_event *bp = t->ptrace_bps[nr];
628         int err = 0;
629
630         if (!bp) {
631                 /*
632                  * Put stub len and type to create an inactive but correct bp.
633                  *
634                  * CHECKME: the previous code returned -EIO if the addr wasn't
635                  * a valid task virtual addr. The new one will return -EINVAL in
636                  *  this case.
637                  * -EINVAL may be what we want for in-kernel breakpoints users,
638                  * but -EIO looks better for ptrace, since we refuse a register
639                  * writing for the user. And anyway this is the previous
640                  * behaviour.
641                  */
642                 bp = ptrace_register_breakpoint(tsk,
643                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
644                                 addr, true);
645                 if (IS_ERR(bp))
646                         err = PTR_ERR(bp);
647                 else
648                         t->ptrace_bps[nr] = bp;
649         } else {
650                 struct perf_event_attr attr = bp->attr;
651
652                 attr.bp_addr = addr;
653                 err = modify_user_hw_breakpoint(bp, &attr);
654         }
655
656         return err;
657 }
658
659 /*
660  * Handle PTRACE_POKEUSR calls for the debug register area.
661  */
662 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
663                                unsigned long val)
664 {
665         struct thread_struct *thread = &tsk->thread;
666         /* There are no DR4 or DR5 registers */
667         int rc = -EIO;
668
669         if (n < HBP_NUM) {
670                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
671         } else if (n == 6) {
672                 thread->debugreg6 = val;
673                 rc = 0;
674         } else if (n == 7) {
675                 rc = ptrace_write_dr7(tsk, val);
676                 if (!rc)
677                         thread->ptrace_dr7 = val;
678         }
679         return rc;
680 }
681
682 /*
683  * These access the current or another (stopped) task's io permission
684  * bitmap for debugging or core dump.
685  */
686 static int ioperm_active(struct task_struct *target,
687                          const struct user_regset *regset)
688 {
689         return target->thread.io_bitmap_max / regset->size;
690 }
691
692 static int ioperm_get(struct task_struct *target,
693                       const struct user_regset *regset,
694                       unsigned int pos, unsigned int count,
695                       void *kbuf, void __user *ubuf)
696 {
697         if (!target->thread.io_bitmap_ptr)
698                 return -ENXIO;
699
700         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
701                                    target->thread.io_bitmap_ptr,
702                                    0, IO_BITMAP_BYTES);
703 }
704
705 /*
706  * Called by kernel/ptrace.c when detaching..
707  *
708  * Make sure the single step bit is not set.
709  */
710 void ptrace_disable(struct task_struct *child)
711 {
712         user_disable_single_step(child);
713 }
714
715 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
716 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
717 #endif
718
719 long arch_ptrace(struct task_struct *child, long request,
720                  unsigned long addr, unsigned long data)
721 {
722         int ret;
723         unsigned long __user *datap = (unsigned long __user *)data;
724
725         switch (request) {
726         /* read the word at location addr in the USER area. */
727         case PTRACE_PEEKUSR: {
728                 unsigned long tmp;
729
730                 ret = -EIO;
731                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
732                         break;
733
734                 tmp = 0;  /* Default return condition */
735                 if (addr < sizeof(struct user_regs_struct))
736                         tmp = getreg(child, addr);
737                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
738                          addr <= offsetof(struct user, u_debugreg[7])) {
739                         addr -= offsetof(struct user, u_debugreg[0]);
740                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
741                 }
742                 ret = put_user(tmp, datap);
743                 break;
744         }
745
746         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
747                 ret = -EIO;
748                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
749                         break;
750
751                 if (addr < sizeof(struct user_regs_struct))
752                         ret = putreg(child, addr, data);
753                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
754                          addr <= offsetof(struct user, u_debugreg[7])) {
755                         addr -= offsetof(struct user, u_debugreg[0]);
756                         ret = ptrace_set_debugreg(child,
757                                                   addr / sizeof(data), data);
758                 }
759                 break;
760
761         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
762                 return copy_regset_to_user(child,
763                                            task_user_regset_view(current),
764                                            REGSET_GENERAL,
765                                            0, sizeof(struct user_regs_struct),
766                                            datap);
767
768         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
769                 return copy_regset_from_user(child,
770                                              task_user_regset_view(current),
771                                              REGSET_GENERAL,
772                                              0, sizeof(struct user_regs_struct),
773                                              datap);
774
775         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
776                 return copy_regset_to_user(child,
777                                            task_user_regset_view(current),
778                                            REGSET_FP,
779                                            0, sizeof(struct user_i387_struct),
780                                            datap);
781
782         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
783                 return copy_regset_from_user(child,
784                                              task_user_regset_view(current),
785                                              REGSET_FP,
786                                              0, sizeof(struct user_i387_struct),
787                                              datap);
788
789 #ifdef CONFIG_X86_32
790         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
791                 return copy_regset_to_user(child, &user_x86_32_view,
792                                            REGSET_XFP,
793                                            0, sizeof(struct user_fxsr_struct),
794                                            datap) ? -EIO : 0;
795
796         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
797                 return copy_regset_from_user(child, &user_x86_32_view,
798                                              REGSET_XFP,
799                                              0, sizeof(struct user_fxsr_struct),
800                                              datap) ? -EIO : 0;
801 #endif
802
803 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
804         case PTRACE_GET_THREAD_AREA:
805                 if ((int) addr < 0)
806                         return -EIO;
807                 ret = do_get_thread_area(child, addr,
808                                         (struct user_desc __user *)data);
809                 break;
810
811         case PTRACE_SET_THREAD_AREA:
812                 if ((int) addr < 0)
813                         return -EIO;
814                 ret = do_set_thread_area(child, addr,
815                                         (struct user_desc __user *)data, 0);
816                 break;
817 #endif
818
819 #ifdef CONFIG_X86_64
820                 /* normal 64bit interface to access TLS data.
821                    Works just like arch_prctl, except that the arguments
822                    are reversed. */
823         case PTRACE_ARCH_PRCTL:
824                 ret = do_arch_prctl_64(child, data, addr);
825                 break;
826 #endif
827
828         default:
829                 ret = ptrace_request(child, request, addr, data);
830                 break;
831         }
832
833         return ret;
834 }
835
836 #ifdef CONFIG_IA32_EMULATION
837
838 #include <linux/compat.h>
839 #include <linux/syscalls.h>
840 #include <asm/ia32.h>
841 #include <asm/user32.h>
842
843 #define R32(l,q)                                                        \
844         case offsetof(struct user32, regs.l):                           \
845                 regs->q = value; break
846
847 #define SEG32(rs)                                                       \
848         case offsetof(struct user32, regs.rs):                          \
849                 return set_segment_reg(child,                           \
850                                        offsetof(struct user_regs_struct, rs), \
851                                        value);                          \
852                 break
853
854 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
855 {
856         struct pt_regs *regs = task_pt_regs(child);
857
858         switch (regno) {
859
860         SEG32(cs);
861         SEG32(ds);
862         SEG32(es);
863         SEG32(fs);
864         SEG32(gs);
865         SEG32(ss);
866
867         R32(ebx, bx);
868         R32(ecx, cx);
869         R32(edx, dx);
870         R32(edi, di);
871         R32(esi, si);
872         R32(ebp, bp);
873         R32(eax, ax);
874         R32(eip, ip);
875         R32(esp, sp);
876
877         case offsetof(struct user32, regs.orig_eax):
878                 /*
879                  * Warning: bizarre corner case fixup here.  A 32-bit
880                  * debugger setting orig_eax to -1 wants to disable
881                  * syscall restart.  Make sure that the syscall
882                  * restart code sign-extends orig_ax.  Also make sure
883                  * we interpret the -ERESTART* codes correctly if
884                  * loaded into regs->ax in case the task is not
885                  * actually still sitting at the exit from a 32-bit
886                  * syscall with TS_COMPAT still set.
887                  */
888                 regs->orig_ax = value;
889                 if (syscall_get_nr(child, regs) >= 0)
890                         child->thread_info.status |= TS_I386_REGS_POKED;
891                 break;
892
893         case offsetof(struct user32, regs.eflags):
894                 return set_flags(child, value);
895
896         case offsetof(struct user32, u_debugreg[0]) ...
897                 offsetof(struct user32, u_debugreg[7]):
898                 regno -= offsetof(struct user32, u_debugreg[0]);
899                 return ptrace_set_debugreg(child, regno / 4, value);
900
901         default:
902                 if (regno > sizeof(struct user32) || (regno & 3))
903                         return -EIO;
904
905                 /*
906                  * Other dummy fields in the virtual user structure
907                  * are ignored
908                  */
909                 break;
910         }
911         return 0;
912 }
913
914 #undef R32
915 #undef SEG32
916
917 #define R32(l,q)                                                        \
918         case offsetof(struct user32, regs.l):                           \
919                 *val = regs->q; break
920
921 #define SEG32(rs)                                                       \
922         case offsetof(struct user32, regs.rs):                          \
923                 *val = get_segment_reg(child,                           \
924                                        offsetof(struct user_regs_struct, rs)); \
925                 break
926
927 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
928 {
929         struct pt_regs *regs = task_pt_regs(child);
930
931         switch (regno) {
932
933         SEG32(ds);
934         SEG32(es);
935         SEG32(fs);
936         SEG32(gs);
937
938         R32(cs, cs);
939         R32(ss, ss);
940         R32(ebx, bx);
941         R32(ecx, cx);
942         R32(edx, dx);
943         R32(edi, di);
944         R32(esi, si);
945         R32(ebp, bp);
946         R32(eax, ax);
947         R32(orig_eax, orig_ax);
948         R32(eip, ip);
949         R32(esp, sp);
950
951         case offsetof(struct user32, regs.eflags):
952                 *val = get_flags(child);
953                 break;
954
955         case offsetof(struct user32, u_debugreg[0]) ...
956                 offsetof(struct user32, u_debugreg[7]):
957                 regno -= offsetof(struct user32, u_debugreg[0]);
958                 *val = ptrace_get_debugreg(child, regno / 4);
959                 break;
960
961         default:
962                 if (regno > sizeof(struct user32) || (regno & 3))
963                         return -EIO;
964
965                 /*
966                  * Other dummy fields in the virtual user structure
967                  * are ignored
968                  */
969                 *val = 0;
970                 break;
971         }
972         return 0;
973 }
974
975 #undef R32
976 #undef SEG32
977
978 static int genregs32_get(struct task_struct *target,
979                          const struct user_regset *regset,
980                          unsigned int pos, unsigned int count,
981                          void *kbuf, void __user *ubuf)
982 {
983         if (kbuf) {
984                 compat_ulong_t *k = kbuf;
985                 while (count >= sizeof(*k)) {
986                         getreg32(target, pos, k++);
987                         count -= sizeof(*k);
988                         pos += sizeof(*k);
989                 }
990         } else {
991                 compat_ulong_t __user *u = ubuf;
992                 while (count >= sizeof(*u)) {
993                         compat_ulong_t word;
994                         getreg32(target, pos, &word);
995                         if (__put_user(word, u++))
996                                 return -EFAULT;
997                         count -= sizeof(*u);
998                         pos += sizeof(*u);
999                 }
1000         }
1001
1002         return 0;
1003 }
1004
1005 static int genregs32_set(struct task_struct *target,
1006                          const struct user_regset *regset,
1007                          unsigned int pos, unsigned int count,
1008                          const void *kbuf, const void __user *ubuf)
1009 {
1010         int ret = 0;
1011         if (kbuf) {
1012                 const compat_ulong_t *k = kbuf;
1013                 while (count >= sizeof(*k) && !ret) {
1014                         ret = putreg32(target, pos, *k++);
1015                         count -= sizeof(*k);
1016                         pos += sizeof(*k);
1017                 }
1018         } else {
1019                 const compat_ulong_t __user *u = ubuf;
1020                 while (count >= sizeof(*u) && !ret) {
1021                         compat_ulong_t word;
1022                         ret = __get_user(word, u++);
1023                         if (ret)
1024                                 break;
1025                         ret = putreg32(target, pos, word);
1026                         count -= sizeof(*u);
1027                         pos += sizeof(*u);
1028                 }
1029         }
1030         return ret;
1031 }
1032
1033 static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1034                              compat_ulong_t caddr, compat_ulong_t cdata)
1035 {
1036         unsigned long addr = caddr;
1037         unsigned long data = cdata;
1038         void __user *datap = compat_ptr(data);
1039         int ret;
1040         __u32 val;
1041
1042         switch (request) {
1043         case PTRACE_PEEKUSR:
1044                 ret = getreg32(child, addr, &val);
1045                 if (ret == 0)
1046                         ret = put_user(val, (__u32 __user *)datap);
1047                 break;
1048
1049         case PTRACE_POKEUSR:
1050                 ret = putreg32(child, addr, data);
1051                 break;
1052
1053         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1054                 return copy_regset_to_user(child, &user_x86_32_view,
1055                                            REGSET_GENERAL,
1056                                            0, sizeof(struct user_regs_struct32),
1057                                            datap);
1058
1059         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1060                 return copy_regset_from_user(child, &user_x86_32_view,
1061                                              REGSET_GENERAL, 0,
1062                                              sizeof(struct user_regs_struct32),
1063                                              datap);
1064
1065         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1066                 return copy_regset_to_user(child, &user_x86_32_view,
1067                                            REGSET_FP, 0,
1068                                            sizeof(struct user_i387_ia32_struct),
1069                                            datap);
1070
1071         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1072                 return copy_regset_from_user(
1073                         child, &user_x86_32_view, REGSET_FP,
1074                         0, sizeof(struct user_i387_ia32_struct), datap);
1075
1076         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1077                 return copy_regset_to_user(child, &user_x86_32_view,
1078                                            REGSET_XFP, 0,
1079                                            sizeof(struct user32_fxsr_struct),
1080                                            datap);
1081
1082         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1083                 return copy_regset_from_user(child, &user_x86_32_view,
1084                                              REGSET_XFP, 0,
1085                                              sizeof(struct user32_fxsr_struct),
1086                                              datap);
1087
1088         case PTRACE_GET_THREAD_AREA:
1089         case PTRACE_SET_THREAD_AREA:
1090                 return arch_ptrace(child, request, addr, data);
1091
1092         default:
1093                 return compat_ptrace_request(child, request, addr, data);
1094         }
1095
1096         return ret;
1097 }
1098 #endif /* CONFIG_IA32_EMULATION */
1099
1100 #ifdef CONFIG_X86_X32_ABI
1101 static long x32_arch_ptrace(struct task_struct *child,
1102                             compat_long_t request, compat_ulong_t caddr,
1103                             compat_ulong_t cdata)
1104 {
1105         unsigned long addr = caddr;
1106         unsigned long data = cdata;
1107         void __user *datap = compat_ptr(data);
1108         int ret;
1109
1110         switch (request) {
1111         /* Read 32bits at location addr in the USER area.  Only allow
1112            to return the lower 32bits of segment and debug registers.  */
1113         case PTRACE_PEEKUSR: {
1114                 u32 tmp;
1115
1116                 ret = -EIO;
1117                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1118                     addr < offsetof(struct user_regs_struct, cs))
1119                         break;
1120
1121                 tmp = 0;  /* Default return condition */
1122                 if (addr < sizeof(struct user_regs_struct))
1123                         tmp = getreg(child, addr);
1124                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1125                          addr <= offsetof(struct user, u_debugreg[7])) {
1126                         addr -= offsetof(struct user, u_debugreg[0]);
1127                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1128                 }
1129                 ret = put_user(tmp, (__u32 __user *)datap);
1130                 break;
1131         }
1132
1133         /* Write the word at location addr in the USER area.  Only allow
1134            to update segment and debug registers with the upper 32bits
1135            zero-extended. */
1136         case PTRACE_POKEUSR:
1137                 ret = -EIO;
1138                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1139                     addr < offsetof(struct user_regs_struct, cs))
1140                         break;
1141
1142                 if (addr < sizeof(struct user_regs_struct))
1143                         ret = putreg(child, addr, data);
1144                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1145                          addr <= offsetof(struct user, u_debugreg[7])) {
1146                         addr -= offsetof(struct user, u_debugreg[0]);
1147                         ret = ptrace_set_debugreg(child,
1148                                                   addr / sizeof(data), data);
1149                 }
1150                 break;
1151
1152         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1153                 return copy_regset_to_user(child,
1154                                            task_user_regset_view(current),
1155                                            REGSET_GENERAL,
1156                                            0, sizeof(struct user_regs_struct),
1157                                            datap);
1158
1159         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1160                 return copy_regset_from_user(child,
1161                                              task_user_regset_view(current),
1162                                              REGSET_GENERAL,
1163                                              0, sizeof(struct user_regs_struct),
1164                                              datap);
1165
1166         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1167                 return copy_regset_to_user(child,
1168                                            task_user_regset_view(current),
1169                                            REGSET_FP,
1170                                            0, sizeof(struct user_i387_struct),
1171                                            datap);
1172
1173         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1174                 return copy_regset_from_user(child,
1175                                              task_user_regset_view(current),
1176                                              REGSET_FP,
1177                                              0, sizeof(struct user_i387_struct),
1178                                              datap);
1179
1180         default:
1181                 return compat_ptrace_request(child, request, addr, data);
1182         }
1183
1184         return ret;
1185 }
1186 #endif
1187
1188 #ifdef CONFIG_COMPAT
1189 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1190                         compat_ulong_t caddr, compat_ulong_t cdata)
1191 {
1192 #ifdef CONFIG_X86_X32_ABI
1193         if (!in_ia32_syscall())
1194                 return x32_arch_ptrace(child, request, caddr, cdata);
1195 #endif
1196 #ifdef CONFIG_IA32_EMULATION
1197         return ia32_arch_ptrace(child, request, caddr, cdata);
1198 #else
1199         return 0;
1200 #endif
1201 }
1202 #endif  /* CONFIG_COMPAT */
1203
1204 #ifdef CONFIG_X86_64
1205
1206 static struct user_regset x86_64_regsets[] __ro_after_init = {
1207         [REGSET_GENERAL] = {
1208                 .core_note_type = NT_PRSTATUS,
1209                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1210                 .size = sizeof(long), .align = sizeof(long),
1211                 .get = genregs_get, .set = genregs_set
1212         },
1213         [REGSET_FP] = {
1214                 .core_note_type = NT_PRFPREG,
1215                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1216                 .size = sizeof(long), .align = sizeof(long),
1217                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1218         },
1219         [REGSET_XSTATE] = {
1220                 .core_note_type = NT_X86_XSTATE,
1221                 .size = sizeof(u64), .align = sizeof(u64),
1222                 .active = xstateregs_active, .get = xstateregs_get,
1223                 .set = xstateregs_set
1224         },
1225         [REGSET_IOPERM64] = {
1226                 .core_note_type = NT_386_IOPERM,
1227                 .n = IO_BITMAP_LONGS,
1228                 .size = sizeof(long), .align = sizeof(long),
1229                 .active = ioperm_active, .get = ioperm_get
1230         },
1231 };
1232
1233 static const struct user_regset_view user_x86_64_view = {
1234         .name = "x86_64", .e_machine = EM_X86_64,
1235         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1236 };
1237
1238 #else  /* CONFIG_X86_32 */
1239
1240 #define user_regs_struct32      user_regs_struct
1241 #define genregs32_get           genregs_get
1242 #define genregs32_set           genregs_set
1243
1244 #endif  /* CONFIG_X86_64 */
1245
1246 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1247 static struct user_regset x86_32_regsets[] __ro_after_init = {
1248         [REGSET_GENERAL] = {
1249                 .core_note_type = NT_PRSTATUS,
1250                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1251                 .size = sizeof(u32), .align = sizeof(u32),
1252                 .get = genregs32_get, .set = genregs32_set
1253         },
1254         [REGSET_FP] = {
1255                 .core_note_type = NT_PRFPREG,
1256                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1257                 .size = sizeof(u32), .align = sizeof(u32),
1258                 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1259         },
1260         [REGSET_XFP] = {
1261                 .core_note_type = NT_PRXFPREG,
1262                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1263                 .size = sizeof(u32), .align = sizeof(u32),
1264                 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1265         },
1266         [REGSET_XSTATE] = {
1267                 .core_note_type = NT_X86_XSTATE,
1268                 .size = sizeof(u64), .align = sizeof(u64),
1269                 .active = xstateregs_active, .get = xstateregs_get,
1270                 .set = xstateregs_set
1271         },
1272         [REGSET_TLS] = {
1273                 .core_note_type = NT_386_TLS,
1274                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1275                 .size = sizeof(struct user_desc),
1276                 .align = sizeof(struct user_desc),
1277                 .active = regset_tls_active,
1278                 .get = regset_tls_get, .set = regset_tls_set
1279         },
1280         [REGSET_IOPERM32] = {
1281                 .core_note_type = NT_386_IOPERM,
1282                 .n = IO_BITMAP_BYTES / sizeof(u32),
1283                 .size = sizeof(u32), .align = sizeof(u32),
1284                 .active = ioperm_active, .get = ioperm_get
1285         },
1286 };
1287
1288 static const struct user_regset_view user_x86_32_view = {
1289         .name = "i386", .e_machine = EM_386,
1290         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1291 };
1292 #endif
1293
1294 /*
1295  * This represents bytes 464..511 in the memory layout exported through
1296  * the REGSET_XSTATE interface.
1297  */
1298 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1299
1300 void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1301 {
1302 #ifdef CONFIG_X86_64
1303         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1304 #endif
1305 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1306         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1307 #endif
1308         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1309 }
1310
1311 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1312 {
1313 #ifdef CONFIG_IA32_EMULATION
1314         if (!user_64bit_mode(task_pt_regs(task)))
1315 #endif
1316 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1317                 return &user_x86_32_view;
1318 #endif
1319 #ifdef CONFIG_X86_64
1320         return &user_x86_64_view;
1321 #endif
1322 }
1323
1324 void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1325 {
1326         struct task_struct *tsk = current;
1327
1328         tsk->thread.trap_nr = X86_TRAP_DB;
1329         tsk->thread.error_code = error_code;
1330
1331         /* Send us the fake SIGTRAP */
1332         force_sig_fault(SIGTRAP, si_code,
1333                         user_mode(regs) ? (void __user *)regs->ip : NULL);
1334 }
1335
1336 void user_single_step_report(struct pt_regs *regs)
1337 {
1338         send_sigtrap(regs, 0, TRAP_BRKPT);
1339 }