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1/* By Ross Biro 1/23/92 */
2/*
3 * Pentium III FXSR, SSE support
4 * Gareth Hughes <gareth@valinux.com>, May 2000
5 */
6
7#include <linux/kernel.h>
8#include <linux/sched.h>
9#include <linux/mm.h>
10#include <linux/smp.h>
11#include <linux/errno.h>
12#include <linux/slab.h>
13#include <linux/ptrace.h>
14#include <linux/tracehook.h>
15#include <linux/user.h>
16#include <linux/elf.h>
17#include <linux/security.h>
18#include <linux/audit.h>
19#include <linux/seccomp.h>
20#include <linux/signal.h>
21#include <linux/perf_event.h>
22#include <linux/hw_breakpoint.h>
23#include <linux/rcupdate.h>
24#include <linux/export.h>
25#include <linux/context_tracking.h>
26
27#include <linux/uaccess.h>
28#include <asm/pgtable.h>
29#include <asm/processor.h>
30#include <asm/fpu/internal.h>
31#include <asm/fpu/signal.h>
32#include <asm/fpu/regset.h>
33#include <asm/debugreg.h>
34#include <asm/ldt.h>
35#include <asm/desc.h>
36#include <asm/prctl.h>
37#include <asm/proto.h>
38#include <asm/hw_breakpoint.h>
39#include <asm/traps.h>
40#include <asm/syscall.h>
41
42#include "tls.h"
43
44enum x86_regset {
45 REGSET_GENERAL,
46 REGSET_FP,
47 REGSET_XFP,
48 REGSET_IOPERM64 = REGSET_XFP,
49 REGSET_XSTATE,
50 REGSET_TLS,
51 REGSET_IOPERM32,
52};
53
54struct pt_regs_offset {
55 const char *name;
56 int offset;
57};
58
59#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
60#define REG_OFFSET_END {.name = NULL, .offset = 0}
61
62static const struct pt_regs_offset regoffset_table[] = {
63#ifdef CONFIG_X86_64
64 REG_OFFSET_NAME(r15),
65 REG_OFFSET_NAME(r14),
66 REG_OFFSET_NAME(r13),
67 REG_OFFSET_NAME(r12),
68 REG_OFFSET_NAME(r11),
69 REG_OFFSET_NAME(r10),
70 REG_OFFSET_NAME(r9),
71 REG_OFFSET_NAME(r8),
72#endif
73 REG_OFFSET_NAME(bx),
74 REG_OFFSET_NAME(cx),
75 REG_OFFSET_NAME(dx),
76 REG_OFFSET_NAME(si),
77 REG_OFFSET_NAME(di),
78 REG_OFFSET_NAME(bp),
79 REG_OFFSET_NAME(ax),
80#ifdef CONFIG_X86_32
81 REG_OFFSET_NAME(ds),
82 REG_OFFSET_NAME(es),
83 REG_OFFSET_NAME(fs),
84 REG_OFFSET_NAME(gs),
85#endif
86 REG_OFFSET_NAME(orig_ax),
87 REG_OFFSET_NAME(ip),
88 REG_OFFSET_NAME(cs),
89 REG_OFFSET_NAME(flags),
90 REG_OFFSET_NAME(sp),
91 REG_OFFSET_NAME(ss),
92 REG_OFFSET_END,
93};
94
95/**
96 * regs_query_register_offset() - query register offset from its name
97 * @name: the name of a register
98 *
99 * regs_query_register_offset() returns the offset of a register in struct
100 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
101 */
102int regs_query_register_offset(const char *name)
103{
104 const struct pt_regs_offset *roff;
105 for (roff = regoffset_table; roff->name != NULL; roff++)
106 if (!strcmp(roff->name, name))
107 return roff->offset;
108 return -EINVAL;
109}
110
111/**
112 * regs_query_register_name() - query register name from its offset
113 * @offset: the offset of a register in struct pt_regs.
114 *
115 * regs_query_register_name() returns the name of a register from its
116 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
117 */
118const char *regs_query_register_name(unsigned int offset)
119{
120 const struct pt_regs_offset *roff;
121 for (roff = regoffset_table; roff->name != NULL; roff++)
122 if (roff->offset == offset)
123 return roff->name;
124 return NULL;
125}
126
127/*
128 * does not yet catch signals sent when the child dies.
129 * in exit.c or in signal.c.
130 */
131
132/*
133 * Determines which flags the user has access to [1 = access, 0 = no access].
134 */
135#define FLAG_MASK_32 ((unsigned long) \
136 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
137 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
138 X86_EFLAGS_SF | X86_EFLAGS_TF | \
139 X86_EFLAGS_DF | X86_EFLAGS_OF | \
140 X86_EFLAGS_RF | X86_EFLAGS_AC))
141
142/*
143 * Determines whether a value may be installed in a segment register.
144 */
145static inline bool invalid_selector(u16 value)
146{
147 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
148}
149
150#ifdef CONFIG_X86_32
151
152#define FLAG_MASK FLAG_MASK_32
153
154/*
155 * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
156 * when it traps. The previous stack will be directly underneath the saved
157 * registers, and 'sp/ss' won't even have been saved. Thus the '®s->sp'.
158 *
159 * Now, if the stack is empty, '®s->sp' is out of range. In this
160 * case we try to take the previous stack. To always return a non-null
161 * stack pointer we fall back to regs as stack if no previous stack
162 * exists.
163 *
164 * This is valid only for kernel mode traps.
165 */
166unsigned long kernel_stack_pointer(struct pt_regs *regs)
167{
168 unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
169 unsigned long sp = (unsigned long)®s->sp;
170 u32 *prev_esp;
171
172 if (context == (sp & ~(THREAD_SIZE - 1)))
173 return sp;
174
175 prev_esp = (u32 *)(context);
176 if (*prev_esp)
177 return (unsigned long)*prev_esp;
178
179 return (unsigned long)regs;
180}
181EXPORT_SYMBOL_GPL(kernel_stack_pointer);
182
183static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
184{
185 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
186 return ®s->bx + (regno >> 2);
187}
188
189static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
190{
191 /*
192 * Returning the value truncates it to 16 bits.
193 */
194 unsigned int retval;
195 if (offset != offsetof(struct user_regs_struct, gs))
196 retval = *pt_regs_access(task_pt_regs(task), offset);
197 else {
198 if (task == current)
199 retval = get_user_gs(task_pt_regs(task));
200 else
201 retval = task_user_gs(task);
202 }
203 return retval;
204}
205
206static int set_segment_reg(struct task_struct *task,
207 unsigned long offset, u16 value)
208{
209 /*
210 * The value argument was already truncated to 16 bits.
211 */
212 if (invalid_selector(value))
213 return -EIO;
214
215 /*
216 * For %cs and %ss we cannot permit a null selector.
217 * We can permit a bogus selector as long as it has USER_RPL.
218 * Null selectors are fine for other segment registers, but
219 * we will never get back to user mode with invalid %cs or %ss
220 * and will take the trap in iret instead. Much code relies
221 * on user_mode() to distinguish a user trap frame (which can
222 * safely use invalid selectors) from a kernel trap frame.
223 */
224 switch (offset) {
225 case offsetof(struct user_regs_struct, cs):
226 case offsetof(struct user_regs_struct, ss):
227 if (unlikely(value == 0))
228 return -EIO;
229
230 default:
231 *pt_regs_access(task_pt_regs(task), offset) = value;
232 break;
233
234 case offsetof(struct user_regs_struct, gs):
235 if (task == current)
236 set_user_gs(task_pt_regs(task), value);
237 else
238 task_user_gs(task) = value;
239 }
240
241 return 0;
242}
243
244#else /* CONFIG_X86_64 */
245
246#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
247
248static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
249{
250 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
251 return ®s->r15 + (offset / sizeof(regs->r15));
252}
253
254static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
255{
256 /*
257 * Returning the value truncates it to 16 bits.
258 */
259 unsigned int seg;
260
261 switch (offset) {
262 case offsetof(struct user_regs_struct, fs):
263 if (task == current) {
264 /* Older gas can't assemble movq %?s,%r?? */
265 asm("movl %%fs,%0" : "=r" (seg));
266 return seg;
267 }
268 return task->thread.fsindex;
269 case offsetof(struct user_regs_struct, gs):
270 if (task == current) {
271 asm("movl %%gs,%0" : "=r" (seg));
272 return seg;
273 }
274 return task->thread.gsindex;
275 case offsetof(struct user_regs_struct, ds):
276 if (task == current) {
277 asm("movl %%ds,%0" : "=r" (seg));
278 return seg;
279 }
280 return task->thread.ds;
281 case offsetof(struct user_regs_struct, es):
282 if (task == current) {
283 asm("movl %%es,%0" : "=r" (seg));
284 return seg;
285 }
286 return task->thread.es;
287
288 case offsetof(struct user_regs_struct, cs):
289 case offsetof(struct user_regs_struct, ss):
290 break;
291 }
292 return *pt_regs_access(task_pt_regs(task), offset);
293}
294
295static int set_segment_reg(struct task_struct *task,
296 unsigned long offset, u16 value)
297{
298 /*
299 * The value argument was already truncated to 16 bits.
300 */
301 if (invalid_selector(value))
302 return -EIO;
303
304 switch (offset) {
305 case offsetof(struct user_regs_struct,fs):
306 task->thread.fsindex = value;
307 if (task == current)
308 loadsegment(fs, task->thread.fsindex);
309 break;
310 case offsetof(struct user_regs_struct,gs):
311 task->thread.gsindex = value;
312 if (task == current)
313 load_gs_index(task->thread.gsindex);
314 break;
315 case offsetof(struct user_regs_struct,ds):
316 task->thread.ds = value;
317 if (task == current)
318 loadsegment(ds, task->thread.ds);
319 break;
320 case offsetof(struct user_regs_struct,es):
321 task->thread.es = value;
322 if (task == current)
323 loadsegment(es, task->thread.es);
324 break;
325
326 /*
327 * Can't actually change these in 64-bit mode.
328 */
329 case offsetof(struct user_regs_struct,cs):
330 if (unlikely(value == 0))
331 return -EIO;
332 task_pt_regs(task)->cs = value;
333 break;
334 case offsetof(struct user_regs_struct,ss):
335 if (unlikely(value == 0))
336 return -EIO;
337 task_pt_regs(task)->ss = value;
338 break;
339 }
340
341 return 0;
342}
343
344#endif /* CONFIG_X86_32 */
345
346static unsigned long get_flags(struct task_struct *task)
347{
348 unsigned long retval = task_pt_regs(task)->flags;
349
350 /*
351 * If the debugger set TF, hide it from the readout.
352 */
353 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
354 retval &= ~X86_EFLAGS_TF;
355
356 return retval;
357}
358
359static int set_flags(struct task_struct *task, unsigned long value)
360{
361 struct pt_regs *regs = task_pt_regs(task);
362
363 /*
364 * If the user value contains TF, mark that
365 * it was not "us" (the debugger) that set it.
366 * If not, make sure it stays set if we had.
367 */
368 if (value & X86_EFLAGS_TF)
369 clear_tsk_thread_flag(task, TIF_FORCED_TF);
370 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
371 value |= X86_EFLAGS_TF;
372
373 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
374
375 return 0;
376}
377
378static int putreg(struct task_struct *child,
379 unsigned long offset, unsigned long value)
380{
381 switch (offset) {
382 case offsetof(struct user_regs_struct, cs):
383 case offsetof(struct user_regs_struct, ds):
384 case offsetof(struct user_regs_struct, es):
385 case offsetof(struct user_regs_struct, fs):
386 case offsetof(struct user_regs_struct, gs):
387 case offsetof(struct user_regs_struct, ss):
388 return set_segment_reg(child, offset, value);
389
390 case offsetof(struct user_regs_struct, flags):
391 return set_flags(child, value);
392
393#ifdef CONFIG_X86_64
394 case offsetof(struct user_regs_struct,fs_base):
395 if (value >= TASK_SIZE_MAX)
396 return -EIO;
397 /*
398 * When changing the segment base, use do_arch_prctl
399 * to set either thread.fs or thread.fsindex and the
400 * corresponding GDT slot.
401 */
402 if (child->thread.fsbase != value)
403 return do_arch_prctl(child, ARCH_SET_FS, value);
404 return 0;
405 case offsetof(struct user_regs_struct,gs_base):
406 /*
407 * Exactly the same here as the %fs handling above.
408 */
409 if (value >= TASK_SIZE_MAX)
410 return -EIO;
411 if (child->thread.gsbase != value)
412 return do_arch_prctl(child, ARCH_SET_GS, value);
413 return 0;
414#endif
415 }
416
417 *pt_regs_access(task_pt_regs(child), offset) = value;
418 return 0;
419}
420
421static unsigned long getreg(struct task_struct *task, unsigned long offset)
422{
423 switch (offset) {
424 case offsetof(struct user_regs_struct, cs):
425 case offsetof(struct user_regs_struct, ds):
426 case offsetof(struct user_regs_struct, es):
427 case offsetof(struct user_regs_struct, fs):
428 case offsetof(struct user_regs_struct, gs):
429 case offsetof(struct user_regs_struct, ss):
430 return get_segment_reg(task, offset);
431
432 case offsetof(struct user_regs_struct, flags):
433 return get_flags(task);
434
435#ifdef CONFIG_X86_64
436 case offsetof(struct user_regs_struct, fs_base): {
437 /*
438 * XXX: This will not behave as expected if called on
439 * current or if fsindex != 0.
440 */
441 return task->thread.fsbase;
442 }
443 case offsetof(struct user_regs_struct, gs_base): {
444 /*
445 * XXX: This will not behave as expected if called on
446 * current or if fsindex != 0.
447 */
448 return task->thread.gsbase;
449 }
450#endif
451 }
452
453 return *pt_regs_access(task_pt_regs(task), offset);
454}
455
456static int genregs_get(struct task_struct *target,
457 const struct user_regset *regset,
458 unsigned int pos, unsigned int count,
459 void *kbuf, void __user *ubuf)
460{
461 if (kbuf) {
462 unsigned long *k = kbuf;
463 while (count >= sizeof(*k)) {
464 *k++ = getreg(target, pos);
465 count -= sizeof(*k);
466 pos += sizeof(*k);
467 }
468 } else {
469 unsigned long __user *u = ubuf;
470 while (count >= sizeof(*u)) {
471 if (__put_user(getreg(target, pos), u++))
472 return -EFAULT;
473 count -= sizeof(*u);
474 pos += sizeof(*u);
475 }
476 }
477
478 return 0;
479}
480
481static int genregs_set(struct task_struct *target,
482 const struct user_regset *regset,
483 unsigned int pos, unsigned int count,
484 const void *kbuf, const void __user *ubuf)
485{
486 int ret = 0;
487 if (kbuf) {
488 const unsigned long *k = kbuf;
489 while (count >= sizeof(*k) && !ret) {
490 ret = putreg(target, pos, *k++);
491 count -= sizeof(*k);
492 pos += sizeof(*k);
493 }
494 } else {
495 const unsigned long __user *u = ubuf;
496 while (count >= sizeof(*u) && !ret) {
497 unsigned long word;
498 ret = __get_user(word, u++);
499 if (ret)
500 break;
501 ret = putreg(target, pos, word);
502 count -= sizeof(*u);
503 pos += sizeof(*u);
504 }
505 }
506 return ret;
507}
508
509static void ptrace_triggered(struct perf_event *bp,
510 struct perf_sample_data *data,
511 struct pt_regs *regs)
512{
513 int i;
514 struct thread_struct *thread = &(current->thread);
515
516 /*
517 * Store in the virtual DR6 register the fact that the breakpoint
518 * was hit so the thread's debugger will see it.
519 */
520 for (i = 0; i < HBP_NUM; i++) {
521 if (thread->ptrace_bps[i] == bp)
522 break;
523 }
524
525 thread->debugreg6 |= (DR_TRAP0 << i);
526}
527
528/*
529 * Walk through every ptrace breakpoints for this thread and
530 * build the dr7 value on top of their attributes.
531 *
532 */
533static unsigned long ptrace_get_dr7(struct perf_event *bp[])
534{
535 int i;
536 int dr7 = 0;
537 struct arch_hw_breakpoint *info;
538
539 for (i = 0; i < HBP_NUM; i++) {
540 if (bp[i] && !bp[i]->attr.disabled) {
541 info = counter_arch_bp(bp[i]);
542 dr7 |= encode_dr7(i, info->len, info->type);
543 }
544 }
545
546 return dr7;
547}
548
549static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
550 int len, int type, bool disabled)
551{
552 int err, bp_len, bp_type;
553
554 err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
555 if (!err) {
556 attr->bp_len = bp_len;
557 attr->bp_type = bp_type;
558 attr->disabled = disabled;
559 }
560
561 return err;
562}
563
564static struct perf_event *
565ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
566 unsigned long addr, bool disabled)
567{
568 struct perf_event_attr attr;
569 int err;
570
571 ptrace_breakpoint_init(&attr);
572 attr.bp_addr = addr;
573
574 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
575 if (err)
576 return ERR_PTR(err);
577
578 return register_user_hw_breakpoint(&attr, ptrace_triggered,
579 NULL, tsk);
580}
581
582static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
583 int disabled)
584{
585 struct perf_event_attr attr = bp->attr;
586 int err;
587
588 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
589 if (err)
590 return err;
591
592 return modify_user_hw_breakpoint(bp, &attr);
593}
594
595/*
596 * Handle ptrace writes to debug register 7.
597 */
598static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
599{
600 struct thread_struct *thread = &tsk->thread;
601 unsigned long old_dr7;
602 bool second_pass = false;
603 int i, rc, ret = 0;
604
605 data &= ~DR_CONTROL_RESERVED;
606 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
607
608restore:
609 rc = 0;
610 for (i = 0; i < HBP_NUM; i++) {
611 unsigned len, type;
612 bool disabled = !decode_dr7(data, i, &len, &type);
613 struct perf_event *bp = thread->ptrace_bps[i];
614
615 if (!bp) {
616 if (disabled)
617 continue;
618
619 bp = ptrace_register_breakpoint(tsk,
620 len, type, 0, disabled);
621 if (IS_ERR(bp)) {
622 rc = PTR_ERR(bp);
623 break;
624 }
625
626 thread->ptrace_bps[i] = bp;
627 continue;
628 }
629
630 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
631 if (rc)
632 break;
633 }
634
635 /* Restore if the first pass failed, second_pass shouldn't fail. */
636 if (rc && !WARN_ON(second_pass)) {
637 ret = rc;
638 data = old_dr7;
639 second_pass = true;
640 goto restore;
641 }
642
643 return ret;
644}
645
646/*
647 * Handle PTRACE_PEEKUSR calls for the debug register area.
648 */
649static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
650{
651 struct thread_struct *thread = &tsk->thread;
652 unsigned long val = 0;
653
654 if (n < HBP_NUM) {
655 struct perf_event *bp = thread->ptrace_bps[n];
656
657 if (bp)
658 val = bp->hw.info.address;
659 } else if (n == 6) {
660 val = thread->debugreg6;
661 } else if (n == 7) {
662 val = thread->ptrace_dr7;
663 }
664 return val;
665}
666
667static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
668 unsigned long addr)
669{
670 struct thread_struct *t = &tsk->thread;
671 struct perf_event *bp = t->ptrace_bps[nr];
672 int err = 0;
673
674 if (!bp) {
675 /*
676 * Put stub len and type to create an inactive but correct bp.
677 *
678 * CHECKME: the previous code returned -EIO if the addr wasn't
679 * a valid task virtual addr. The new one will return -EINVAL in
680 * this case.
681 * -EINVAL may be what we want for in-kernel breakpoints users,
682 * but -EIO looks better for ptrace, since we refuse a register
683 * writing for the user. And anyway this is the previous
684 * behaviour.
685 */
686 bp = ptrace_register_breakpoint(tsk,
687 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
688 addr, true);
689 if (IS_ERR(bp))
690 err = PTR_ERR(bp);
691 else
692 t->ptrace_bps[nr] = bp;
693 } else {
694 struct perf_event_attr attr = bp->attr;
695
696 attr.bp_addr = addr;
697 err = modify_user_hw_breakpoint(bp, &attr);
698 }
699
700 return err;
701}
702
703/*
704 * Handle PTRACE_POKEUSR calls for the debug register area.
705 */
706static int ptrace_set_debugreg(struct task_struct *tsk, int n,
707 unsigned long val)
708{
709 struct thread_struct *thread = &tsk->thread;
710 /* There are no DR4 or DR5 registers */
711 int rc = -EIO;
712
713 if (n < HBP_NUM) {
714 rc = ptrace_set_breakpoint_addr(tsk, n, val);
715 } else if (n == 6) {
716 thread->debugreg6 = val;
717 rc = 0;
718 } else if (n == 7) {
719 rc = ptrace_write_dr7(tsk, val);
720 if (!rc)
721 thread->ptrace_dr7 = val;
722 }
723 return rc;
724}
725
726/*
727 * These access the current or another (stopped) task's io permission
728 * bitmap for debugging or core dump.
729 */
730static int ioperm_active(struct task_struct *target,
731 const struct user_regset *regset)
732{
733 return target->thread.io_bitmap_max / regset->size;
734}
735
736static int ioperm_get(struct task_struct *target,
737 const struct user_regset *regset,
738 unsigned int pos, unsigned int count,
739 void *kbuf, void __user *ubuf)
740{
741 if (!target->thread.io_bitmap_ptr)
742 return -ENXIO;
743
744 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
745 target->thread.io_bitmap_ptr,
746 0, IO_BITMAP_BYTES);
747}
748
749/*
750 * Called by kernel/ptrace.c when detaching..
751 *
752 * Make sure the single step bit is not set.
753 */
754void ptrace_disable(struct task_struct *child)
755{
756 user_disable_single_step(child);
757#ifdef TIF_SYSCALL_EMU
758 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
759#endif
760}
761
762#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
763static const struct user_regset_view user_x86_32_view; /* Initialized below. */
764#endif
765
766long arch_ptrace(struct task_struct *child, long request,
767 unsigned long addr, unsigned long data)
768{
769 int ret;
770 unsigned long __user *datap = (unsigned long __user *)data;
771
772 switch (request) {
773 /* read the word at location addr in the USER area. */
774 case PTRACE_PEEKUSR: {
775 unsigned long tmp;
776
777 ret = -EIO;
778 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
779 break;
780
781 tmp = 0; /* Default return condition */
782 if (addr < sizeof(struct user_regs_struct))
783 tmp = getreg(child, addr);
784 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
785 addr <= offsetof(struct user, u_debugreg[7])) {
786 addr -= offsetof(struct user, u_debugreg[0]);
787 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
788 }
789 ret = put_user(tmp, datap);
790 break;
791 }
792
793 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
794 ret = -EIO;
795 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
796 break;
797
798 if (addr < sizeof(struct user_regs_struct))
799 ret = putreg(child, addr, data);
800 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
801 addr <= offsetof(struct user, u_debugreg[7])) {
802 addr -= offsetof(struct user, u_debugreg[0]);
803 ret = ptrace_set_debugreg(child,
804 addr / sizeof(data), data);
805 }
806 break;
807
808 case PTRACE_GETREGS: /* Get all gp regs from the child. */
809 return copy_regset_to_user(child,
810 task_user_regset_view(current),
811 REGSET_GENERAL,
812 0, sizeof(struct user_regs_struct),
813 datap);
814
815 case PTRACE_SETREGS: /* Set all gp regs in the child. */
816 return copy_regset_from_user(child,
817 task_user_regset_view(current),
818 REGSET_GENERAL,
819 0, sizeof(struct user_regs_struct),
820 datap);
821
822 case PTRACE_GETFPREGS: /* Get the child FPU state. */
823 return copy_regset_to_user(child,
824 task_user_regset_view(current),
825 REGSET_FP,
826 0, sizeof(struct user_i387_struct),
827 datap);
828
829 case PTRACE_SETFPREGS: /* Set the child FPU state. */
830 return copy_regset_from_user(child,
831 task_user_regset_view(current),
832 REGSET_FP,
833 0, sizeof(struct user_i387_struct),
834 datap);
835
836#ifdef CONFIG_X86_32
837 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
838 return copy_regset_to_user(child, &user_x86_32_view,
839 REGSET_XFP,
840 0, sizeof(struct user_fxsr_struct),
841 datap) ? -EIO : 0;
842
843 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
844 return copy_regset_from_user(child, &user_x86_32_view,
845 REGSET_XFP,
846 0, sizeof(struct user_fxsr_struct),
847 datap) ? -EIO : 0;
848#endif
849
850#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
851 case PTRACE_GET_THREAD_AREA:
852 if ((int) addr < 0)
853 return -EIO;
854 ret = do_get_thread_area(child, addr,
855 (struct user_desc __user *)data);
856 break;
857
858 case PTRACE_SET_THREAD_AREA:
859 if ((int) addr < 0)
860 return -EIO;
861 ret = do_set_thread_area(child, addr,
862 (struct user_desc __user *)data, 0);
863 break;
864#endif
865
866#ifdef CONFIG_X86_64
867 /* normal 64bit interface to access TLS data.
868 Works just like arch_prctl, except that the arguments
869 are reversed. */
870 case PTRACE_ARCH_PRCTL:
871 ret = do_arch_prctl(child, data, addr);
872 break;
873#endif
874
875 default:
876 ret = ptrace_request(child, request, addr, data);
877 break;
878 }
879
880 return ret;
881}
882
883#ifdef CONFIG_IA32_EMULATION
884
885#include <linux/compat.h>
886#include <linux/syscalls.h>
887#include <asm/ia32.h>
888#include <asm/user32.h>
889
890#define R32(l,q) \
891 case offsetof(struct user32, regs.l): \
892 regs->q = value; break
893
894#define SEG32(rs) \
895 case offsetof(struct user32, regs.rs): \
896 return set_segment_reg(child, \
897 offsetof(struct user_regs_struct, rs), \
898 value); \
899 break
900
901static int putreg32(struct task_struct *child, unsigned regno, u32 value)
902{
903 struct pt_regs *regs = task_pt_regs(child);
904
905 switch (regno) {
906
907 SEG32(cs);
908 SEG32(ds);
909 SEG32(es);
910 SEG32(fs);
911 SEG32(gs);
912 SEG32(ss);
913
914 R32(ebx, bx);
915 R32(ecx, cx);
916 R32(edx, dx);
917 R32(edi, di);
918 R32(esi, si);
919 R32(ebp, bp);
920 R32(eax, ax);
921 R32(eip, ip);
922 R32(esp, sp);
923
924 case offsetof(struct user32, regs.orig_eax):
925 /*
926 * Warning: bizarre corner case fixup here. A 32-bit
927 * debugger setting orig_eax to -1 wants to disable
928 * syscall restart. Make sure that the syscall
929 * restart code sign-extends orig_ax. Also make sure
930 * we interpret the -ERESTART* codes correctly if
931 * loaded into regs->ax in case the task is not
932 * actually still sitting at the exit from a 32-bit
933 * syscall with TS_COMPAT still set.
934 */
935 regs->orig_ax = value;
936 if (syscall_get_nr(child, regs) >= 0)
937 child->thread.status |= TS_I386_REGS_POKED;
938 break;
939
940 case offsetof(struct user32, regs.eflags):
941 return set_flags(child, value);
942
943 case offsetof(struct user32, u_debugreg[0]) ...
944 offsetof(struct user32, u_debugreg[7]):
945 regno -= offsetof(struct user32, u_debugreg[0]);
946 return ptrace_set_debugreg(child, regno / 4, value);
947
948 default:
949 if (regno > sizeof(struct user32) || (regno & 3))
950 return -EIO;
951
952 /*
953 * Other dummy fields in the virtual user structure
954 * are ignored
955 */
956 break;
957 }
958 return 0;
959}
960
961#undef R32
962#undef SEG32
963
964#define R32(l,q) \
965 case offsetof(struct user32, regs.l): \
966 *val = regs->q; break
967
968#define SEG32(rs) \
969 case offsetof(struct user32, regs.rs): \
970 *val = get_segment_reg(child, \
971 offsetof(struct user_regs_struct, rs)); \
972 break
973
974static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
975{
976 struct pt_regs *regs = task_pt_regs(child);
977
978 switch (regno) {
979
980 SEG32(ds);
981 SEG32(es);
982 SEG32(fs);
983 SEG32(gs);
984
985 R32(cs, cs);
986 R32(ss, ss);
987 R32(ebx, bx);
988 R32(ecx, cx);
989 R32(edx, dx);
990 R32(edi, di);
991 R32(esi, si);
992 R32(ebp, bp);
993 R32(eax, ax);
994 R32(orig_eax, orig_ax);
995 R32(eip, ip);
996 R32(esp, sp);
997
998 case offsetof(struct user32, regs.eflags):
999 *val = get_flags(child);
1000 break;
1001
1002 case offsetof(struct user32, u_debugreg[0]) ...
1003 offsetof(struct user32, u_debugreg[7]):
1004 regno -= offsetof(struct user32, u_debugreg[0]);
1005 *val = ptrace_get_debugreg(child, regno / 4);
1006 break;
1007
1008 default:
1009 if (regno > sizeof(struct user32) || (regno & 3))
1010 return -EIO;
1011
1012 /*
1013 * Other dummy fields in the virtual user structure
1014 * are ignored
1015 */
1016 *val = 0;
1017 break;
1018 }
1019 return 0;
1020}
1021
1022#undef R32
1023#undef SEG32
1024
1025static int genregs32_get(struct task_struct *target,
1026 const struct user_regset *regset,
1027 unsigned int pos, unsigned int count,
1028 void *kbuf, void __user *ubuf)
1029{
1030 if (kbuf) {
1031 compat_ulong_t *k = kbuf;
1032 while (count >= sizeof(*k)) {
1033 getreg32(target, pos, k++);
1034 count -= sizeof(*k);
1035 pos += sizeof(*k);
1036 }
1037 } else {
1038 compat_ulong_t __user *u = ubuf;
1039 while (count >= sizeof(*u)) {
1040 compat_ulong_t word;
1041 getreg32(target, pos, &word);
1042 if (__put_user(word, u++))
1043 return -EFAULT;
1044 count -= sizeof(*u);
1045 pos += sizeof(*u);
1046 }
1047 }
1048
1049 return 0;
1050}
1051
1052static int genregs32_set(struct task_struct *target,
1053 const struct user_regset *regset,
1054 unsigned int pos, unsigned int count,
1055 const void *kbuf, const void __user *ubuf)
1056{
1057 int ret = 0;
1058 if (kbuf) {
1059 const compat_ulong_t *k = kbuf;
1060 while (count >= sizeof(*k) && !ret) {
1061 ret = putreg32(target, pos, *k++);
1062 count -= sizeof(*k);
1063 pos += sizeof(*k);
1064 }
1065 } else {
1066 const compat_ulong_t __user *u = ubuf;
1067 while (count >= sizeof(*u) && !ret) {
1068 compat_ulong_t word;
1069 ret = __get_user(word, u++);
1070 if (ret)
1071 break;
1072 ret = putreg32(target, pos, word);
1073 count -= sizeof(*u);
1074 pos += sizeof(*u);
1075 }
1076 }
1077 return ret;
1078}
1079
1080static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1081 compat_ulong_t caddr, compat_ulong_t cdata)
1082{
1083 unsigned long addr = caddr;
1084 unsigned long data = cdata;
1085 void __user *datap = compat_ptr(data);
1086 int ret;
1087 __u32 val;
1088
1089 switch (request) {
1090 case PTRACE_PEEKUSR:
1091 ret = getreg32(child, addr, &val);
1092 if (ret == 0)
1093 ret = put_user(val, (__u32 __user *)datap);
1094 break;
1095
1096 case PTRACE_POKEUSR:
1097 ret = putreg32(child, addr, data);
1098 break;
1099
1100 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1101 return copy_regset_to_user(child, &user_x86_32_view,
1102 REGSET_GENERAL,
1103 0, sizeof(struct user_regs_struct32),
1104 datap);
1105
1106 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1107 return copy_regset_from_user(child, &user_x86_32_view,
1108 REGSET_GENERAL, 0,
1109 sizeof(struct user_regs_struct32),
1110 datap);
1111
1112 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1113 return copy_regset_to_user(child, &user_x86_32_view,
1114 REGSET_FP, 0,
1115 sizeof(struct user_i387_ia32_struct),
1116 datap);
1117
1118 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1119 return copy_regset_from_user(
1120 child, &user_x86_32_view, REGSET_FP,
1121 0, sizeof(struct user_i387_ia32_struct), datap);
1122
1123 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1124 return copy_regset_to_user(child, &user_x86_32_view,
1125 REGSET_XFP, 0,
1126 sizeof(struct user32_fxsr_struct),
1127 datap);
1128
1129 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1130 return copy_regset_from_user(child, &user_x86_32_view,
1131 REGSET_XFP, 0,
1132 sizeof(struct user32_fxsr_struct),
1133 datap);
1134
1135 case PTRACE_GET_THREAD_AREA:
1136 case PTRACE_SET_THREAD_AREA:
1137 return arch_ptrace(child, request, addr, data);
1138
1139 default:
1140 return compat_ptrace_request(child, request, addr, data);
1141 }
1142
1143 return ret;
1144}
1145#endif /* CONFIG_IA32_EMULATION */
1146
1147#ifdef CONFIG_X86_X32_ABI
1148static long x32_arch_ptrace(struct task_struct *child,
1149 compat_long_t request, compat_ulong_t caddr,
1150 compat_ulong_t cdata)
1151{
1152 unsigned long addr = caddr;
1153 unsigned long data = cdata;
1154 void __user *datap = compat_ptr(data);
1155 int ret;
1156
1157 switch (request) {
1158 /* Read 32bits at location addr in the USER area. Only allow
1159 to return the lower 32bits of segment and debug registers. */
1160 case PTRACE_PEEKUSR: {
1161 u32 tmp;
1162
1163 ret = -EIO;
1164 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1165 addr < offsetof(struct user_regs_struct, cs))
1166 break;
1167
1168 tmp = 0; /* Default return condition */
1169 if (addr < sizeof(struct user_regs_struct))
1170 tmp = getreg(child, addr);
1171 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1172 addr <= offsetof(struct user, u_debugreg[7])) {
1173 addr -= offsetof(struct user, u_debugreg[0]);
1174 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1175 }
1176 ret = put_user(tmp, (__u32 __user *)datap);
1177 break;
1178 }
1179
1180 /* Write the word at location addr in the USER area. Only allow
1181 to update segment and debug registers with the upper 32bits
1182 zero-extended. */
1183 case PTRACE_POKEUSR:
1184 ret = -EIO;
1185 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1186 addr < offsetof(struct user_regs_struct, cs))
1187 break;
1188
1189 if (addr < sizeof(struct user_regs_struct))
1190 ret = putreg(child, addr, data);
1191 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1192 addr <= offsetof(struct user, u_debugreg[7])) {
1193 addr -= offsetof(struct user, u_debugreg[0]);
1194 ret = ptrace_set_debugreg(child,
1195 addr / sizeof(data), data);
1196 }
1197 break;
1198
1199 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1200 return copy_regset_to_user(child,
1201 task_user_regset_view(current),
1202 REGSET_GENERAL,
1203 0, sizeof(struct user_regs_struct),
1204 datap);
1205
1206 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1207 return copy_regset_from_user(child,
1208 task_user_regset_view(current),
1209 REGSET_GENERAL,
1210 0, sizeof(struct user_regs_struct),
1211 datap);
1212
1213 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1214 return copy_regset_to_user(child,
1215 task_user_regset_view(current),
1216 REGSET_FP,
1217 0, sizeof(struct user_i387_struct),
1218 datap);
1219
1220 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1221 return copy_regset_from_user(child,
1222 task_user_regset_view(current),
1223 REGSET_FP,
1224 0, sizeof(struct user_i387_struct),
1225 datap);
1226
1227 default:
1228 return compat_ptrace_request(child, request, addr, data);
1229 }
1230
1231 return ret;
1232}
1233#endif
1234
1235#ifdef CONFIG_COMPAT
1236long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1237 compat_ulong_t caddr, compat_ulong_t cdata)
1238{
1239#ifdef CONFIG_X86_X32_ABI
1240 if (!in_ia32_syscall())
1241 return x32_arch_ptrace(child, request, caddr, cdata);
1242#endif
1243#ifdef CONFIG_IA32_EMULATION
1244 return ia32_arch_ptrace(child, request, caddr, cdata);
1245#else
1246 return 0;
1247#endif
1248}
1249#endif /* CONFIG_COMPAT */
1250
1251#ifdef CONFIG_X86_64
1252
1253static struct user_regset x86_64_regsets[] __ro_after_init = {
1254 [REGSET_GENERAL] = {
1255 .core_note_type = NT_PRSTATUS,
1256 .n = sizeof(struct user_regs_struct) / sizeof(long),
1257 .size = sizeof(long), .align = sizeof(long),
1258 .get = genregs_get, .set = genregs_set
1259 },
1260 [REGSET_FP] = {
1261 .core_note_type = NT_PRFPREG,
1262 .n = sizeof(struct user_i387_struct) / sizeof(long),
1263 .size = sizeof(long), .align = sizeof(long),
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_IOPERM64] = {
1273 .core_note_type = NT_386_IOPERM,
1274 .n = IO_BITMAP_LONGS,
1275 .size = sizeof(long), .align = sizeof(long),
1276 .active = ioperm_active, .get = ioperm_get
1277 },
1278};
1279
1280static const struct user_regset_view user_x86_64_view = {
1281 .name = "x86_64", .e_machine = EM_X86_64,
1282 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1283};
1284
1285#else /* CONFIG_X86_32 */
1286
1287#define user_regs_struct32 user_regs_struct
1288#define genregs32_get genregs_get
1289#define genregs32_set genregs_set
1290
1291#endif /* CONFIG_X86_64 */
1292
1293#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1294static struct user_regset x86_32_regsets[] __ro_after_init = {
1295 [REGSET_GENERAL] = {
1296 .core_note_type = NT_PRSTATUS,
1297 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1298 .size = sizeof(u32), .align = sizeof(u32),
1299 .get = genregs32_get, .set = genregs32_set
1300 },
1301 [REGSET_FP] = {
1302 .core_note_type = NT_PRFPREG,
1303 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1304 .size = sizeof(u32), .align = sizeof(u32),
1305 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1306 },
1307 [REGSET_XFP] = {
1308 .core_note_type = NT_PRXFPREG,
1309 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1310 .size = sizeof(u32), .align = sizeof(u32),
1311 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1312 },
1313 [REGSET_XSTATE] = {
1314 .core_note_type = NT_X86_XSTATE,
1315 .size = sizeof(u64), .align = sizeof(u64),
1316 .active = xstateregs_active, .get = xstateregs_get,
1317 .set = xstateregs_set
1318 },
1319 [REGSET_TLS] = {
1320 .core_note_type = NT_386_TLS,
1321 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1322 .size = sizeof(struct user_desc),
1323 .align = sizeof(struct user_desc),
1324 .active = regset_tls_active,
1325 .get = regset_tls_get, .set = regset_tls_set
1326 },
1327 [REGSET_IOPERM32] = {
1328 .core_note_type = NT_386_IOPERM,
1329 .n = IO_BITMAP_BYTES / sizeof(u32),
1330 .size = sizeof(u32), .align = sizeof(u32),
1331 .active = ioperm_active, .get = ioperm_get
1332 },
1333};
1334
1335static const struct user_regset_view user_x86_32_view = {
1336 .name = "i386", .e_machine = EM_386,
1337 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1338};
1339#endif
1340
1341/*
1342 * This represents bytes 464..511 in the memory layout exported through
1343 * the REGSET_XSTATE interface.
1344 */
1345u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1346
1347void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1348{
1349#ifdef CONFIG_X86_64
1350 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1351#endif
1352#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1353 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1354#endif
1355 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1356}
1357
1358const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1359{
1360#ifdef CONFIG_IA32_EMULATION
1361 if (!user_64bit_mode(task_pt_regs(task)))
1362#endif
1363#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1364 return &user_x86_32_view;
1365#endif
1366#ifdef CONFIG_X86_64
1367 return &user_x86_64_view;
1368#endif
1369}
1370
1371static void fill_sigtrap_info(struct task_struct *tsk,
1372 struct pt_regs *regs,
1373 int error_code, int si_code,
1374 struct siginfo *info)
1375{
1376 tsk->thread.trap_nr = X86_TRAP_DB;
1377 tsk->thread.error_code = error_code;
1378
1379 memset(info, 0, sizeof(*info));
1380 info->si_signo = SIGTRAP;
1381 info->si_code = si_code;
1382 info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1383}
1384
1385void user_single_step_siginfo(struct task_struct *tsk,
1386 struct pt_regs *regs,
1387 struct siginfo *info)
1388{
1389 fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1390}
1391
1392void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1393 int error_code, int si_code)
1394{
1395 struct siginfo info;
1396
1397 fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1398 /* Send us the fake SIGTRAP */
1399 force_sig_info(SIGTRAP, &info, tsk);
1400}
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->virtual_dr6 |= (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->virtual_dr6 ^ DR6_RESERVED; /* Flip back to arch polarity */
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->virtual_dr6 = val ^ DR6_RESERVED; /* Flip to positive polarity */
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#ifdef CONFIG_X86_64
708static const struct user_regset_view user_x86_64_view; /* Initialized below. */
709#endif
710
711long arch_ptrace(struct task_struct *child, long request,
712 unsigned long addr, unsigned long data)
713{
714 int ret;
715 unsigned long __user *datap = (unsigned long __user *)data;
716
717#ifdef CONFIG_X86_64
718 /* This is native 64-bit ptrace() */
719 const struct user_regset_view *regset_view = &user_x86_64_view;
720#else
721 /* This is native 32-bit ptrace() */
722 const struct user_regset_view *regset_view = &user_x86_32_view;
723#endif
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 regset_view,
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 regset_view,
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 regset_view,
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 regset_view,
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
854static int putreg32(struct task_struct *child, unsigned regno, u32 value)
855{
856 struct pt_regs *regs = task_pt_regs(child);
857 int ret;
858
859 switch (regno) {
860
861 SEG32(cs);
862 SEG32(ds);
863 SEG32(es);
864
865 /*
866 * A 32-bit ptracer on a 64-bit kernel expects that writing
867 * FS or GS will also update the base. This is needed for
868 * operations like PTRACE_SETREGS to fully restore a saved
869 * CPU state.
870 */
871
872 case offsetof(struct user32, regs.fs):
873 ret = set_segment_reg(child,
874 offsetof(struct user_regs_struct, fs),
875 value);
876 if (ret == 0)
877 child->thread.fsbase =
878 x86_fsgsbase_read_task(child, value);
879 return ret;
880
881 case offsetof(struct user32, regs.gs):
882 ret = set_segment_reg(child,
883 offsetof(struct user_regs_struct, gs),
884 value);
885 if (ret == 0)
886 child->thread.gsbase =
887 x86_fsgsbase_read_task(child, value);
888 return ret;
889
890 SEG32(ss);
891
892 R32(ebx, bx);
893 R32(ecx, cx);
894 R32(edx, dx);
895 R32(edi, di);
896 R32(esi, si);
897 R32(ebp, bp);
898 R32(eax, ax);
899 R32(eip, ip);
900 R32(esp, sp);
901
902 case offsetof(struct user32, regs.orig_eax):
903 /*
904 * Warning: bizarre corner case fixup here. A 32-bit
905 * debugger setting orig_eax to -1 wants to disable
906 * syscall restart. Make sure that the syscall
907 * restart code sign-extends orig_ax. Also make sure
908 * we interpret the -ERESTART* codes correctly if
909 * loaded into regs->ax in case the task is not
910 * actually still sitting at the exit from a 32-bit
911 * syscall with TS_COMPAT still set.
912 */
913 regs->orig_ax = value;
914 if (syscall_get_nr(child, regs) != -1)
915 child->thread_info.status |= TS_I386_REGS_POKED;
916 break;
917
918 case offsetof(struct user32, regs.eflags):
919 return set_flags(child, value);
920
921 case offsetof(struct user32, u_debugreg[0]) ...
922 offsetof(struct user32, u_debugreg[7]):
923 regno -= offsetof(struct user32, u_debugreg[0]);
924 return ptrace_set_debugreg(child, regno / 4, value);
925
926 default:
927 if (regno > sizeof(struct user32) || (regno & 3))
928 return -EIO;
929
930 /*
931 * Other dummy fields in the virtual user structure
932 * are ignored
933 */
934 break;
935 }
936 return 0;
937}
938
939#undef R32
940#undef SEG32
941
942#define R32(l,q) \
943 case offsetof(struct user32, regs.l): \
944 *val = regs->q; break
945
946#define SEG32(rs) \
947 case offsetof(struct user32, regs.rs): \
948 *val = get_segment_reg(child, \
949 offsetof(struct user_regs_struct, rs)); \
950 break
951
952static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
953{
954 struct pt_regs *regs = task_pt_regs(child);
955
956 switch (regno) {
957
958 SEG32(ds);
959 SEG32(es);
960 SEG32(fs);
961 SEG32(gs);
962
963 R32(cs, cs);
964 R32(ss, ss);
965 R32(ebx, bx);
966 R32(ecx, cx);
967 R32(edx, dx);
968 R32(edi, di);
969 R32(esi, si);
970 R32(ebp, bp);
971 R32(eax, ax);
972 R32(orig_eax, orig_ax);
973 R32(eip, ip);
974 R32(esp, sp);
975
976 case offsetof(struct user32, regs.eflags):
977 *val = get_flags(child);
978 break;
979
980 case offsetof(struct user32, u_debugreg[0]) ...
981 offsetof(struct user32, u_debugreg[7]):
982 regno -= offsetof(struct user32, u_debugreg[0]);
983 *val = ptrace_get_debugreg(child, regno / 4);
984 break;
985
986 default:
987 if (regno > sizeof(struct user32) || (regno & 3))
988 return -EIO;
989
990 /*
991 * Other dummy fields in the virtual user structure
992 * are ignored
993 */
994 *val = 0;
995 break;
996 }
997 return 0;
998}
999
1000#undef R32
1001#undef SEG32
1002
1003static int genregs32_get(struct task_struct *target,
1004 const struct user_regset *regset,
1005 struct membuf to)
1006{
1007 int reg;
1008
1009 for (reg = 0; to.left; reg++) {
1010 u32 val;
1011 getreg32(target, reg * 4, &val);
1012 membuf_store(&to, val);
1013 }
1014 return 0;
1015}
1016
1017static int genregs32_set(struct task_struct *target,
1018 const struct user_regset *regset,
1019 unsigned int pos, unsigned int count,
1020 const void *kbuf, const void __user *ubuf)
1021{
1022 int ret = 0;
1023 if (kbuf) {
1024 const compat_ulong_t *k = kbuf;
1025 while (count >= sizeof(*k) && !ret) {
1026 ret = putreg32(target, pos, *k++);
1027 count -= sizeof(*k);
1028 pos += sizeof(*k);
1029 }
1030 } else {
1031 const compat_ulong_t __user *u = ubuf;
1032 while (count >= sizeof(*u) && !ret) {
1033 compat_ulong_t word;
1034 ret = __get_user(word, u++);
1035 if (ret)
1036 break;
1037 ret = putreg32(target, pos, word);
1038 count -= sizeof(*u);
1039 pos += sizeof(*u);
1040 }
1041 }
1042 return ret;
1043}
1044
1045static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1046 compat_ulong_t caddr, compat_ulong_t cdata)
1047{
1048 unsigned long addr = caddr;
1049 unsigned long data = cdata;
1050 void __user *datap = compat_ptr(data);
1051 int ret;
1052 __u32 val;
1053
1054 switch (request) {
1055 case PTRACE_PEEKUSR:
1056 ret = getreg32(child, addr, &val);
1057 if (ret == 0)
1058 ret = put_user(val, (__u32 __user *)datap);
1059 break;
1060
1061 case PTRACE_POKEUSR:
1062 ret = putreg32(child, addr, data);
1063 break;
1064
1065 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1066 return copy_regset_to_user(child, &user_x86_32_view,
1067 REGSET_GENERAL,
1068 0, sizeof(struct user_regs_struct32),
1069 datap);
1070
1071 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1072 return copy_regset_from_user(child, &user_x86_32_view,
1073 REGSET_GENERAL, 0,
1074 sizeof(struct user_regs_struct32),
1075 datap);
1076
1077 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1078 return copy_regset_to_user(child, &user_x86_32_view,
1079 REGSET_FP, 0,
1080 sizeof(struct user_i387_ia32_struct),
1081 datap);
1082
1083 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1084 return copy_regset_from_user(
1085 child, &user_x86_32_view, REGSET_FP,
1086 0, sizeof(struct user_i387_ia32_struct), datap);
1087
1088 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1089 return copy_regset_to_user(child, &user_x86_32_view,
1090 REGSET_XFP, 0,
1091 sizeof(struct user32_fxsr_struct),
1092 datap);
1093
1094 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1095 return copy_regset_from_user(child, &user_x86_32_view,
1096 REGSET_XFP, 0,
1097 sizeof(struct user32_fxsr_struct),
1098 datap);
1099
1100 case PTRACE_GET_THREAD_AREA:
1101 case PTRACE_SET_THREAD_AREA:
1102 return arch_ptrace(child, request, addr, data);
1103
1104 default:
1105 return compat_ptrace_request(child, request, addr, data);
1106 }
1107
1108 return ret;
1109}
1110#endif /* CONFIG_IA32_EMULATION */
1111
1112#ifdef CONFIG_X86_X32_ABI
1113static long x32_arch_ptrace(struct task_struct *child,
1114 compat_long_t request, compat_ulong_t caddr,
1115 compat_ulong_t cdata)
1116{
1117 unsigned long addr = caddr;
1118 unsigned long data = cdata;
1119 void __user *datap = compat_ptr(data);
1120 int ret;
1121
1122 switch (request) {
1123 /* Read 32bits at location addr in the USER area. Only allow
1124 to return the lower 32bits of segment and debug registers. */
1125 case PTRACE_PEEKUSR: {
1126 u32 tmp;
1127
1128 ret = -EIO;
1129 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1130 addr < offsetof(struct user_regs_struct, cs))
1131 break;
1132
1133 tmp = 0; /* Default return condition */
1134 if (addr < sizeof(struct user_regs_struct))
1135 tmp = getreg(child, addr);
1136 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1137 addr <= offsetof(struct user, u_debugreg[7])) {
1138 addr -= offsetof(struct user, u_debugreg[0]);
1139 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1140 }
1141 ret = put_user(tmp, (__u32 __user *)datap);
1142 break;
1143 }
1144
1145 /* Write the word at location addr in the USER area. Only allow
1146 to update segment and debug registers with the upper 32bits
1147 zero-extended. */
1148 case PTRACE_POKEUSR:
1149 ret = -EIO;
1150 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1151 addr < offsetof(struct user_regs_struct, cs))
1152 break;
1153
1154 if (addr < sizeof(struct user_regs_struct))
1155 ret = putreg(child, addr, data);
1156 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1157 addr <= offsetof(struct user, u_debugreg[7])) {
1158 addr -= offsetof(struct user, u_debugreg[0]);
1159 ret = ptrace_set_debugreg(child,
1160 addr / sizeof(data), data);
1161 }
1162 break;
1163
1164 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1165 return copy_regset_to_user(child,
1166 &user_x86_64_view,
1167 REGSET_GENERAL,
1168 0, sizeof(struct user_regs_struct),
1169 datap);
1170
1171 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1172 return copy_regset_from_user(child,
1173 &user_x86_64_view,
1174 REGSET_GENERAL,
1175 0, sizeof(struct user_regs_struct),
1176 datap);
1177
1178 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1179 return copy_regset_to_user(child,
1180 &user_x86_64_view,
1181 REGSET_FP,
1182 0, sizeof(struct user_i387_struct),
1183 datap);
1184
1185 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1186 return copy_regset_from_user(child,
1187 &user_x86_64_view,
1188 REGSET_FP,
1189 0, sizeof(struct user_i387_struct),
1190 datap);
1191
1192 default:
1193 return compat_ptrace_request(child, request, addr, data);
1194 }
1195
1196 return ret;
1197}
1198#endif
1199
1200#ifdef CONFIG_COMPAT
1201long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1202 compat_ulong_t caddr, compat_ulong_t cdata)
1203{
1204#ifdef CONFIG_X86_X32_ABI
1205 if (!in_ia32_syscall())
1206 return x32_arch_ptrace(child, request, caddr, cdata);
1207#endif
1208#ifdef CONFIG_IA32_EMULATION
1209 return ia32_arch_ptrace(child, request, caddr, cdata);
1210#else
1211 return 0;
1212#endif
1213}
1214#endif /* CONFIG_COMPAT */
1215
1216#ifdef CONFIG_X86_64
1217
1218static struct user_regset x86_64_regsets[] __ro_after_init = {
1219 [REGSET_GENERAL] = {
1220 .core_note_type = NT_PRSTATUS,
1221 .n = sizeof(struct user_regs_struct) / sizeof(long),
1222 .size = sizeof(long), .align = sizeof(long),
1223 .regset_get = genregs_get, .set = genregs_set
1224 },
1225 [REGSET_FP] = {
1226 .core_note_type = NT_PRFPREG,
1227 .n = sizeof(struct user_i387_struct) / sizeof(long),
1228 .size = sizeof(long), .align = sizeof(long),
1229 .active = regset_xregset_fpregs_active, .regset_get = xfpregs_get, .set = xfpregs_set
1230 },
1231 [REGSET_XSTATE] = {
1232 .core_note_type = NT_X86_XSTATE,
1233 .size = sizeof(u64), .align = sizeof(u64),
1234 .active = xstateregs_active, .regset_get = xstateregs_get,
1235 .set = xstateregs_set
1236 },
1237 [REGSET_IOPERM64] = {
1238 .core_note_type = NT_386_IOPERM,
1239 .n = IO_BITMAP_LONGS,
1240 .size = sizeof(long), .align = sizeof(long),
1241 .active = ioperm_active, .regset_get = ioperm_get
1242 },
1243};
1244
1245static const struct user_regset_view user_x86_64_view = {
1246 .name = "x86_64", .e_machine = EM_X86_64,
1247 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1248};
1249
1250#else /* CONFIG_X86_32 */
1251
1252#define user_regs_struct32 user_regs_struct
1253#define genregs32_get genregs_get
1254#define genregs32_set genregs_set
1255
1256#endif /* CONFIG_X86_64 */
1257
1258#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1259static struct user_regset x86_32_regsets[] __ro_after_init = {
1260 [REGSET_GENERAL] = {
1261 .core_note_type = NT_PRSTATUS,
1262 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1263 .size = sizeof(u32), .align = sizeof(u32),
1264 .regset_get = genregs32_get, .set = genregs32_set
1265 },
1266 [REGSET_FP] = {
1267 .core_note_type = NT_PRFPREG,
1268 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1269 .size = sizeof(u32), .align = sizeof(u32),
1270 .active = regset_fpregs_active, .regset_get = fpregs_get, .set = fpregs_set
1271 },
1272 [REGSET_XFP] = {
1273 .core_note_type = NT_PRXFPREG,
1274 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1275 .size = sizeof(u32), .align = sizeof(u32),
1276 .active = regset_xregset_fpregs_active, .regset_get = xfpregs_get, .set = xfpregs_set
1277 },
1278 [REGSET_XSTATE] = {
1279 .core_note_type = NT_X86_XSTATE,
1280 .size = sizeof(u64), .align = sizeof(u64),
1281 .active = xstateregs_active, .regset_get = xstateregs_get,
1282 .set = xstateregs_set
1283 },
1284 [REGSET_TLS] = {
1285 .core_note_type = NT_386_TLS,
1286 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1287 .size = sizeof(struct user_desc),
1288 .align = sizeof(struct user_desc),
1289 .active = regset_tls_active,
1290 .regset_get = regset_tls_get, .set = regset_tls_set
1291 },
1292 [REGSET_IOPERM32] = {
1293 .core_note_type = NT_386_IOPERM,
1294 .n = IO_BITMAP_BYTES / sizeof(u32),
1295 .size = sizeof(u32), .align = sizeof(u32),
1296 .active = ioperm_active, .regset_get = ioperm_get
1297 },
1298};
1299
1300static const struct user_regset_view user_x86_32_view = {
1301 .name = "i386", .e_machine = EM_386,
1302 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1303};
1304#endif
1305
1306/*
1307 * This represents bytes 464..511 in the memory layout exported through
1308 * the REGSET_XSTATE interface.
1309 */
1310u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1311
1312void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1313{
1314#ifdef CONFIG_X86_64
1315 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1316#endif
1317#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1318 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1319#endif
1320 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1321}
1322
1323/*
1324 * This is used by the core dump code to decide which regset to dump. The
1325 * core dump code writes out the resulting .e_machine and the corresponding
1326 * regsets. This is suboptimal if the task is messing around with its CS.L
1327 * field, but at worst the core dump will end up missing some information.
1328 *
1329 * Unfortunately, it is also used by the broken PTRACE_GETREGSET and
1330 * PTRACE_SETREGSET APIs. These APIs look at the .regsets field but have
1331 * no way to make sure that the e_machine they use matches the caller's
1332 * expectations. The result is that the data format returned by
1333 * PTRACE_GETREGSET depends on the returned CS field (and even the offset
1334 * of the returned CS field depends on its value!) and the data format
1335 * accepted by PTRACE_SETREGSET is determined by the old CS value. The
1336 * upshot is that it is basically impossible to use these APIs correctly.
1337 *
1338 * The best way to fix it in the long run would probably be to add new
1339 * improved ptrace() APIs to read and write registers reliably, possibly by
1340 * allowing userspace to select the ELF e_machine variant that they expect.
1341 */
1342const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1343{
1344#ifdef CONFIG_IA32_EMULATION
1345 if (!user_64bit_mode(task_pt_regs(task)))
1346#endif
1347#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1348 return &user_x86_32_view;
1349#endif
1350#ifdef CONFIG_X86_64
1351 return &user_x86_64_view;
1352#endif
1353}
1354
1355void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1356{
1357 struct task_struct *tsk = current;
1358
1359 tsk->thread.trap_nr = X86_TRAP_DB;
1360 tsk->thread.error_code = error_code;
1361
1362 /* Send us the fake SIGTRAP */
1363 force_sig_fault(SIGTRAP, si_code,
1364 user_mode(regs) ? (void __user *)regs->ip : NULL);
1365}
1366
1367void user_single_step_report(struct pt_regs *regs)
1368{
1369 send_sigtrap(regs, 0, TRAP_BRKPT);
1370}