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1// SPDX-License-Identifier: GPL-2.0-only
2/* By Ross Biro 1/23/92 */
3/*
4 * Pentium III FXSR, SSE support
5 * Gareth Hughes <gareth@valinux.com>, May 2000
6 */
7
8#include <linux/kernel.h>
9#include <linux/sched.h>
10#include <linux/sched/task_stack.h>
11#include <linux/mm.h>
12#include <linux/smp.h>
13#include <linux/errno.h>
14#include <linux/slab.h>
15#include <linux/ptrace.h>
16#include <linux/user.h>
17#include <linux/elf.h>
18#include <linux/security.h>
19#include <linux/audit.h>
20#include <linux/seccomp.h>
21#include <linux/signal.h>
22#include <linux/perf_event.h>
23#include <linux/hw_breakpoint.h>
24#include <linux/rcupdate.h>
25#include <linux/export.h>
26#include <linux/context_tracking.h>
27#include <linux/nospec.h>
28
29#include <linux/uaccess.h>
30#include <asm/processor.h>
31#include <asm/fpu/signal.h>
32#include <asm/fpu/regset.h>
33#include <asm/fpu/xstate.h>
34#include <asm/debugreg.h>
35#include <asm/ldt.h>
36#include <asm/desc.h>
37#include <asm/prctl.h>
38#include <asm/proto.h>
39#include <asm/hw_breakpoint.h>
40#include <asm/traps.h>
41#include <asm/syscall.h>
42#include <asm/fsgsbase.h>
43#include <asm/io_bitmap.h>
44
45#include "tls.h"
46
47enum x86_regset_32 {
48 REGSET32_GENERAL,
49 REGSET32_FP,
50 REGSET32_XFP,
51 REGSET32_XSTATE,
52 REGSET32_TLS,
53 REGSET32_IOPERM,
54};
55
56enum x86_regset_64 {
57 REGSET64_GENERAL,
58 REGSET64_FP,
59 REGSET64_IOPERM,
60 REGSET64_XSTATE,
61 REGSET64_SSP,
62};
63
64#define REGSET_GENERAL \
65({ \
66 BUILD_BUG_ON((int)REGSET32_GENERAL != (int)REGSET64_GENERAL); \
67 REGSET32_GENERAL; \
68})
69
70#define REGSET_FP \
71({ \
72 BUILD_BUG_ON((int)REGSET32_FP != (int)REGSET64_FP); \
73 REGSET32_FP; \
74})
75
76
77struct pt_regs_offset {
78 const char *name;
79 int offset;
80};
81
82#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
83#define REG_OFFSET_END {.name = NULL, .offset = 0}
84
85static const struct pt_regs_offset regoffset_table[] = {
86#ifdef CONFIG_X86_64
87 REG_OFFSET_NAME(r15),
88 REG_OFFSET_NAME(r14),
89 REG_OFFSET_NAME(r13),
90 REG_OFFSET_NAME(r12),
91 REG_OFFSET_NAME(r11),
92 REG_OFFSET_NAME(r10),
93 REG_OFFSET_NAME(r9),
94 REG_OFFSET_NAME(r8),
95#endif
96 REG_OFFSET_NAME(bx),
97 REG_OFFSET_NAME(cx),
98 REG_OFFSET_NAME(dx),
99 REG_OFFSET_NAME(si),
100 REG_OFFSET_NAME(di),
101 REG_OFFSET_NAME(bp),
102 REG_OFFSET_NAME(ax),
103#ifdef CONFIG_X86_32
104 REG_OFFSET_NAME(ds),
105 REG_OFFSET_NAME(es),
106 REG_OFFSET_NAME(fs),
107 REG_OFFSET_NAME(gs),
108#endif
109 REG_OFFSET_NAME(orig_ax),
110 REG_OFFSET_NAME(ip),
111 REG_OFFSET_NAME(cs),
112 REG_OFFSET_NAME(flags),
113 REG_OFFSET_NAME(sp),
114 REG_OFFSET_NAME(ss),
115 REG_OFFSET_END,
116};
117
118/**
119 * regs_query_register_offset() - query register offset from its name
120 * @name: the name of a register
121 *
122 * regs_query_register_offset() returns the offset of a register in struct
123 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
124 */
125int regs_query_register_offset(const char *name)
126{
127 const struct pt_regs_offset *roff;
128 for (roff = regoffset_table; roff->name != NULL; roff++)
129 if (!strcmp(roff->name, name))
130 return roff->offset;
131 return -EINVAL;
132}
133
134/**
135 * regs_query_register_name() - query register name from its offset
136 * @offset: the offset of a register in struct pt_regs.
137 *
138 * regs_query_register_name() returns the name of a register from its
139 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
140 */
141const char *regs_query_register_name(unsigned int offset)
142{
143 const struct pt_regs_offset *roff;
144 for (roff = regoffset_table; roff->name != NULL; roff++)
145 if (roff->offset == offset)
146 return roff->name;
147 return NULL;
148}
149
150/*
151 * does not yet catch signals sent when the child dies.
152 * in exit.c or in signal.c.
153 */
154
155/*
156 * Determines which flags the user has access to [1 = access, 0 = no access].
157 */
158#define FLAG_MASK_32 ((unsigned long) \
159 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
160 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
161 X86_EFLAGS_SF | X86_EFLAGS_TF | \
162 X86_EFLAGS_DF | X86_EFLAGS_OF | \
163 X86_EFLAGS_RF | X86_EFLAGS_AC))
164
165/*
166 * Determines whether a value may be installed in a segment register.
167 */
168static inline bool invalid_selector(u16 value)
169{
170 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
171}
172
173#ifdef CONFIG_X86_32
174
175#define FLAG_MASK FLAG_MASK_32
176
177static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
178{
179 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
180 return ®s->bx + (regno >> 2);
181}
182
183static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
184{
185 /*
186 * Returning the value truncates it to 16 bits.
187 */
188 unsigned int retval;
189 if (offset != offsetof(struct user_regs_struct, gs))
190 retval = *pt_regs_access(task_pt_regs(task), offset);
191 else {
192 if (task == current)
193 savesegment(gs, retval);
194 else
195 retval = task->thread.gs;
196 }
197 return retval;
198}
199
200static int set_segment_reg(struct task_struct *task,
201 unsigned long offset, u16 value)
202{
203 if (WARN_ON_ONCE(task == current))
204 return -EIO;
205
206 /*
207 * The value argument was already truncated to 16 bits.
208 */
209 if (invalid_selector(value))
210 return -EIO;
211
212 /*
213 * For %cs and %ss we cannot permit a null selector.
214 * We can permit a bogus selector as long as it has USER_RPL.
215 * Null selectors are fine for other segment registers, but
216 * we will never get back to user mode with invalid %cs or %ss
217 * and will take the trap in iret instead. Much code relies
218 * on user_mode() to distinguish a user trap frame (which can
219 * safely use invalid selectors) from a kernel trap frame.
220 */
221 switch (offset) {
222 case offsetof(struct user_regs_struct, cs):
223 case offsetof(struct user_regs_struct, ss):
224 if (unlikely(value == 0))
225 return -EIO;
226 fallthrough;
227
228 default:
229 *pt_regs_access(task_pt_regs(task), offset) = value;
230 break;
231
232 case offsetof(struct user_regs_struct, gs):
233 task->thread.gs = value;
234 }
235
236 return 0;
237}
238
239#else /* CONFIG_X86_64 */
240
241#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
242
243static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
244{
245 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
246 return ®s->r15 + (offset / sizeof(regs->r15));
247}
248
249static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
250{
251 /*
252 * Returning the value truncates it to 16 bits.
253 */
254 unsigned int seg;
255
256 switch (offset) {
257 case offsetof(struct user_regs_struct, fs):
258 if (task == current) {
259 /* Older gas can't assemble movq %?s,%r?? */
260 asm("movl %%fs,%0" : "=r" (seg));
261 return seg;
262 }
263 return task->thread.fsindex;
264 case offsetof(struct user_regs_struct, gs):
265 if (task == current) {
266 asm("movl %%gs,%0" : "=r" (seg));
267 return seg;
268 }
269 return task->thread.gsindex;
270 case offsetof(struct user_regs_struct, ds):
271 if (task == current) {
272 asm("movl %%ds,%0" : "=r" (seg));
273 return seg;
274 }
275 return task->thread.ds;
276 case offsetof(struct user_regs_struct, es):
277 if (task == current) {
278 asm("movl %%es,%0" : "=r" (seg));
279 return seg;
280 }
281 return task->thread.es;
282
283 case offsetof(struct user_regs_struct, cs):
284 case offsetof(struct user_regs_struct, ss):
285 break;
286 }
287 return *pt_regs_access(task_pt_regs(task), offset);
288}
289
290static int set_segment_reg(struct task_struct *task,
291 unsigned long offset, u16 value)
292{
293 if (WARN_ON_ONCE(task == current))
294 return -EIO;
295
296 /*
297 * The value argument was already truncated to 16 bits.
298 */
299 if (invalid_selector(value))
300 return -EIO;
301
302 /*
303 * Writes to FS and GS will change the stored selector. Whether
304 * this changes the segment base as well depends on whether
305 * FSGSBASE is enabled.
306 */
307
308 switch (offset) {
309 case offsetof(struct user_regs_struct,fs):
310 task->thread.fsindex = value;
311 break;
312 case offsetof(struct user_regs_struct,gs):
313 task->thread.gsindex = value;
314 break;
315 case offsetof(struct user_regs_struct,ds):
316 task->thread.ds = value;
317 break;
318 case offsetof(struct user_regs_struct,es):
319 task->thread.es = value;
320 break;
321
322 /*
323 * Can't actually change these in 64-bit mode.
324 */
325 case offsetof(struct user_regs_struct,cs):
326 if (unlikely(value == 0))
327 return -EIO;
328 task_pt_regs(task)->cs = value;
329 break;
330 case offsetof(struct user_regs_struct,ss):
331 if (unlikely(value == 0))
332 return -EIO;
333 task_pt_regs(task)->ss = value;
334 break;
335 }
336
337 return 0;
338}
339
340#endif /* CONFIG_X86_32 */
341
342static unsigned long get_flags(struct task_struct *task)
343{
344 unsigned long retval = task_pt_regs(task)->flags;
345
346 /*
347 * If the debugger set TF, hide it from the readout.
348 */
349 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
350 retval &= ~X86_EFLAGS_TF;
351
352 return retval;
353}
354
355static int set_flags(struct task_struct *task, unsigned long value)
356{
357 struct pt_regs *regs = task_pt_regs(task);
358
359 /*
360 * If the user value contains TF, mark that
361 * it was not "us" (the debugger) that set it.
362 * If not, make sure it stays set if we had.
363 */
364 if (value & X86_EFLAGS_TF)
365 clear_tsk_thread_flag(task, TIF_FORCED_TF);
366 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
367 value |= X86_EFLAGS_TF;
368
369 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
370
371 return 0;
372}
373
374static int putreg(struct task_struct *child,
375 unsigned long offset, unsigned long value)
376{
377 switch (offset) {
378 case offsetof(struct user_regs_struct, cs):
379 case offsetof(struct user_regs_struct, ds):
380 case offsetof(struct user_regs_struct, es):
381 case offsetof(struct user_regs_struct, fs):
382 case offsetof(struct user_regs_struct, gs):
383 case offsetof(struct user_regs_struct, ss):
384 return set_segment_reg(child, offset, value);
385
386 case offsetof(struct user_regs_struct, flags):
387 return set_flags(child, value);
388
389#ifdef CONFIG_X86_64
390 case offsetof(struct user_regs_struct,fs_base):
391 if (value >= TASK_SIZE_MAX)
392 return -EIO;
393 x86_fsbase_write_task(child, value);
394 return 0;
395 case offsetof(struct user_regs_struct,gs_base):
396 if (value >= TASK_SIZE_MAX)
397 return -EIO;
398 x86_gsbase_write_task(child, value);
399 return 0;
400#endif
401 }
402
403 *pt_regs_access(task_pt_regs(child), offset) = value;
404 return 0;
405}
406
407static unsigned long getreg(struct task_struct *task, unsigned long offset)
408{
409 switch (offset) {
410 case offsetof(struct user_regs_struct, cs):
411 case offsetof(struct user_regs_struct, ds):
412 case offsetof(struct user_regs_struct, es):
413 case offsetof(struct user_regs_struct, fs):
414 case offsetof(struct user_regs_struct, gs):
415 case offsetof(struct user_regs_struct, ss):
416 return get_segment_reg(task, offset);
417
418 case offsetof(struct user_regs_struct, flags):
419 return get_flags(task);
420
421#ifdef CONFIG_X86_64
422 case offsetof(struct user_regs_struct, fs_base):
423 return x86_fsbase_read_task(task);
424 case offsetof(struct user_regs_struct, gs_base):
425 return x86_gsbase_read_task(task);
426#endif
427 }
428
429 return *pt_regs_access(task_pt_regs(task), offset);
430}
431
432static int genregs_get(struct task_struct *target,
433 const struct user_regset *regset,
434 struct membuf to)
435{
436 int reg;
437
438 for (reg = 0; to.left; reg++)
439 membuf_store(&to, getreg(target, reg * sizeof(unsigned long)));
440 return 0;
441}
442
443static int genregs_set(struct task_struct *target,
444 const struct user_regset *regset,
445 unsigned int pos, unsigned int count,
446 const void *kbuf, const void __user *ubuf)
447{
448 int ret = 0;
449 if (kbuf) {
450 const unsigned long *k = kbuf;
451 while (count >= sizeof(*k) && !ret) {
452 ret = putreg(target, pos, *k++);
453 count -= sizeof(*k);
454 pos += sizeof(*k);
455 }
456 } else {
457 const unsigned long __user *u = ubuf;
458 while (count >= sizeof(*u) && !ret) {
459 unsigned long word;
460 ret = __get_user(word, u++);
461 if (ret)
462 break;
463 ret = putreg(target, pos, word);
464 count -= sizeof(*u);
465 pos += sizeof(*u);
466 }
467 }
468 return ret;
469}
470
471static void ptrace_triggered(struct perf_event *bp,
472 struct perf_sample_data *data,
473 struct pt_regs *regs)
474{
475 int i;
476 struct thread_struct *thread = &(current->thread);
477
478 /*
479 * Store in the virtual DR6 register the fact that the breakpoint
480 * was hit so the thread's debugger will see it.
481 */
482 for (i = 0; i < HBP_NUM; i++) {
483 if (thread->ptrace_bps[i] == bp)
484 break;
485 }
486
487 thread->virtual_dr6 |= (DR_TRAP0 << i);
488}
489
490/*
491 * Walk through every ptrace breakpoints for this thread and
492 * build the dr7 value on top of their attributes.
493 *
494 */
495static unsigned long ptrace_get_dr7(struct perf_event *bp[])
496{
497 int i;
498 int dr7 = 0;
499 struct arch_hw_breakpoint *info;
500
501 for (i = 0; i < HBP_NUM; i++) {
502 if (bp[i] && !bp[i]->attr.disabled) {
503 info = counter_arch_bp(bp[i]);
504 dr7 |= encode_dr7(i, info->len, info->type);
505 }
506 }
507
508 return dr7;
509}
510
511static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
512 int len, int type, bool disabled)
513{
514 int err, bp_len, bp_type;
515
516 err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
517 if (!err) {
518 attr->bp_len = bp_len;
519 attr->bp_type = bp_type;
520 attr->disabled = disabled;
521 }
522
523 return err;
524}
525
526static struct perf_event *
527ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
528 unsigned long addr, bool disabled)
529{
530 struct perf_event_attr attr;
531 int err;
532
533 ptrace_breakpoint_init(&attr);
534 attr.bp_addr = addr;
535
536 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
537 if (err)
538 return ERR_PTR(err);
539
540 return register_user_hw_breakpoint(&attr, ptrace_triggered,
541 NULL, tsk);
542}
543
544static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
545 int disabled)
546{
547 struct perf_event_attr attr = bp->attr;
548 int err;
549
550 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
551 if (err)
552 return err;
553
554 return modify_user_hw_breakpoint(bp, &attr);
555}
556
557/*
558 * Handle ptrace writes to debug register 7.
559 */
560static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
561{
562 struct thread_struct *thread = &tsk->thread;
563 unsigned long old_dr7;
564 bool second_pass = false;
565 int i, rc, ret = 0;
566
567 data &= ~DR_CONTROL_RESERVED;
568 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
569
570restore:
571 rc = 0;
572 for (i = 0; i < HBP_NUM; i++) {
573 unsigned len, type;
574 bool disabled = !decode_dr7(data, i, &len, &type);
575 struct perf_event *bp = thread->ptrace_bps[i];
576
577 if (!bp) {
578 if (disabled)
579 continue;
580
581 bp = ptrace_register_breakpoint(tsk,
582 len, type, 0, disabled);
583 if (IS_ERR(bp)) {
584 rc = PTR_ERR(bp);
585 break;
586 }
587
588 thread->ptrace_bps[i] = bp;
589 continue;
590 }
591
592 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
593 if (rc)
594 break;
595 }
596
597 /* Restore if the first pass failed, second_pass shouldn't fail. */
598 if (rc && !WARN_ON(second_pass)) {
599 ret = rc;
600 data = old_dr7;
601 second_pass = true;
602 goto restore;
603 }
604
605 return ret;
606}
607
608/*
609 * Handle PTRACE_PEEKUSR calls for the debug register area.
610 */
611static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
612{
613 struct thread_struct *thread = &tsk->thread;
614 unsigned long val = 0;
615
616 if (n < HBP_NUM) {
617 int index = array_index_nospec(n, HBP_NUM);
618 struct perf_event *bp = thread->ptrace_bps[index];
619
620 if (bp)
621 val = bp->hw.info.address;
622 } else if (n == 6) {
623 val = thread->virtual_dr6 ^ DR6_RESERVED; /* Flip back to arch polarity */
624 } else if (n == 7) {
625 val = thread->ptrace_dr7;
626 }
627 return val;
628}
629
630static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
631 unsigned long addr)
632{
633 struct thread_struct *t = &tsk->thread;
634 struct perf_event *bp = t->ptrace_bps[nr];
635 int err = 0;
636
637 if (!bp) {
638 /*
639 * Put stub len and type to create an inactive but correct bp.
640 *
641 * CHECKME: the previous code returned -EIO if the addr wasn't
642 * a valid task virtual addr. The new one will return -EINVAL in
643 * this case.
644 * -EINVAL may be what we want for in-kernel breakpoints users,
645 * but -EIO looks better for ptrace, since we refuse a register
646 * writing for the user. And anyway this is the previous
647 * behaviour.
648 */
649 bp = ptrace_register_breakpoint(tsk,
650 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
651 addr, true);
652 if (IS_ERR(bp))
653 err = PTR_ERR(bp);
654 else
655 t->ptrace_bps[nr] = bp;
656 } else {
657 struct perf_event_attr attr = bp->attr;
658
659 attr.bp_addr = addr;
660 err = modify_user_hw_breakpoint(bp, &attr);
661 }
662
663 return err;
664}
665
666/*
667 * Handle PTRACE_POKEUSR calls for the debug register area.
668 */
669static int ptrace_set_debugreg(struct task_struct *tsk, int n,
670 unsigned long val)
671{
672 struct thread_struct *thread = &tsk->thread;
673 /* There are no DR4 or DR5 registers */
674 int rc = -EIO;
675
676 if (n < HBP_NUM) {
677 rc = ptrace_set_breakpoint_addr(tsk, n, val);
678 } else if (n == 6) {
679 thread->virtual_dr6 = val ^ DR6_RESERVED; /* Flip to positive polarity */
680 rc = 0;
681 } else if (n == 7) {
682 rc = ptrace_write_dr7(tsk, val);
683 if (!rc)
684 thread->ptrace_dr7 = val;
685 }
686 return rc;
687}
688
689/*
690 * These access the current or another (stopped) task's io permission
691 * bitmap for debugging or core dump.
692 */
693static int ioperm_active(struct task_struct *target,
694 const struct user_regset *regset)
695{
696 struct io_bitmap *iobm = target->thread.io_bitmap;
697
698 return iobm ? DIV_ROUND_UP(iobm->max, regset->size) : 0;
699}
700
701static int ioperm_get(struct task_struct *target,
702 const struct user_regset *regset,
703 struct membuf to)
704{
705 struct io_bitmap *iobm = target->thread.io_bitmap;
706
707 if (!iobm)
708 return -ENXIO;
709
710 return membuf_write(&to, iobm->bitmap, IO_BITMAP_BYTES);
711}
712
713/*
714 * Called by kernel/ptrace.c when detaching..
715 *
716 * Make sure the single step bit is not set.
717 */
718void ptrace_disable(struct task_struct *child)
719{
720 user_disable_single_step(child);
721}
722
723#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
724static const struct user_regset_view user_x86_32_view; /* Initialized below. */
725#endif
726#ifdef CONFIG_X86_64
727static const struct user_regset_view user_x86_64_view; /* Initialized below. */
728#endif
729
730long arch_ptrace(struct task_struct *child, long request,
731 unsigned long addr, unsigned long data)
732{
733 int ret;
734 unsigned long __user *datap = (unsigned long __user *)data;
735
736#ifdef CONFIG_X86_64
737 /* This is native 64-bit ptrace() */
738 const struct user_regset_view *regset_view = &user_x86_64_view;
739#else
740 /* This is native 32-bit ptrace() */
741 const struct user_regset_view *regset_view = &user_x86_32_view;
742#endif
743
744 switch (request) {
745 /* read the word at location addr in the USER area. */
746 case PTRACE_PEEKUSR: {
747 unsigned long tmp;
748
749 ret = -EIO;
750 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
751 break;
752
753 tmp = 0; /* Default return condition */
754 if (addr < sizeof(struct user_regs_struct))
755 tmp = getreg(child, addr);
756 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
757 addr <= offsetof(struct user, u_debugreg[7])) {
758 addr -= offsetof(struct user, u_debugreg[0]);
759 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
760 }
761 ret = put_user(tmp, datap);
762 break;
763 }
764
765 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
766 ret = -EIO;
767 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
768 break;
769
770 if (addr < sizeof(struct user_regs_struct))
771 ret = putreg(child, addr, data);
772 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
773 addr <= offsetof(struct user, u_debugreg[7])) {
774 addr -= offsetof(struct user, u_debugreg[0]);
775 ret = ptrace_set_debugreg(child,
776 addr / sizeof(data), data);
777 }
778 break;
779
780 case PTRACE_GETREGS: /* Get all gp regs from the child. */
781 return copy_regset_to_user(child,
782 regset_view,
783 REGSET_GENERAL,
784 0, sizeof(struct user_regs_struct),
785 datap);
786
787 case PTRACE_SETREGS: /* Set all gp regs in the child. */
788 return copy_regset_from_user(child,
789 regset_view,
790 REGSET_GENERAL,
791 0, sizeof(struct user_regs_struct),
792 datap);
793
794 case PTRACE_GETFPREGS: /* Get the child FPU state. */
795 return copy_regset_to_user(child,
796 regset_view,
797 REGSET_FP,
798 0, sizeof(struct user_i387_struct),
799 datap);
800
801 case PTRACE_SETFPREGS: /* Set the child FPU state. */
802 return copy_regset_from_user(child,
803 regset_view,
804 REGSET_FP,
805 0, sizeof(struct user_i387_struct),
806 datap);
807
808#ifdef CONFIG_X86_32
809 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
810 return copy_regset_to_user(child, &user_x86_32_view,
811 REGSET32_XFP,
812 0, sizeof(struct user_fxsr_struct),
813 datap) ? -EIO : 0;
814
815 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
816 return copy_regset_from_user(child, &user_x86_32_view,
817 REGSET32_XFP,
818 0, sizeof(struct user_fxsr_struct),
819 datap) ? -EIO : 0;
820#endif
821
822#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
823 case PTRACE_GET_THREAD_AREA:
824 if ((int) addr < 0)
825 return -EIO;
826 ret = do_get_thread_area(child, addr,
827 (struct user_desc __user *)data);
828 break;
829
830 case PTRACE_SET_THREAD_AREA:
831 if ((int) addr < 0)
832 return -EIO;
833 ret = do_set_thread_area(child, addr,
834 (struct user_desc __user *)data, 0);
835 break;
836#endif
837
838#ifdef CONFIG_X86_64
839 /* normal 64bit interface to access TLS data.
840 Works just like arch_prctl, except that the arguments
841 are reversed. */
842 case PTRACE_ARCH_PRCTL:
843 ret = do_arch_prctl_64(child, data, addr);
844 break;
845#endif
846
847 default:
848 ret = ptrace_request(child, request, addr, data);
849 break;
850 }
851
852 return ret;
853}
854
855#ifdef CONFIG_IA32_EMULATION
856
857#include <linux/compat.h>
858#include <linux/syscalls.h>
859#include <asm/ia32.h>
860#include <asm/user32.h>
861
862#define R32(l,q) \
863 case offsetof(struct user32, regs.l): \
864 regs->q = value; break
865
866#define SEG32(rs) \
867 case offsetof(struct user32, regs.rs): \
868 return set_segment_reg(child, \
869 offsetof(struct user_regs_struct, rs), \
870 value); \
871 break
872
873static int putreg32(struct task_struct *child, unsigned regno, u32 value)
874{
875 struct pt_regs *regs = task_pt_regs(child);
876 int ret;
877
878 switch (regno) {
879
880 SEG32(cs);
881 SEG32(ds);
882 SEG32(es);
883
884 /*
885 * A 32-bit ptracer on a 64-bit kernel expects that writing
886 * FS or GS will also update the base. This is needed for
887 * operations like PTRACE_SETREGS to fully restore a saved
888 * CPU state.
889 */
890
891 case offsetof(struct user32, regs.fs):
892 ret = set_segment_reg(child,
893 offsetof(struct user_regs_struct, fs),
894 value);
895 if (ret == 0)
896 child->thread.fsbase =
897 x86_fsgsbase_read_task(child, value);
898 return ret;
899
900 case offsetof(struct user32, regs.gs):
901 ret = set_segment_reg(child,
902 offsetof(struct user_regs_struct, gs),
903 value);
904 if (ret == 0)
905 child->thread.gsbase =
906 x86_fsgsbase_read_task(child, value);
907 return ret;
908
909 SEG32(ss);
910
911 R32(ebx, bx);
912 R32(ecx, cx);
913 R32(edx, dx);
914 R32(edi, di);
915 R32(esi, si);
916 R32(ebp, bp);
917 R32(eax, ax);
918 R32(eip, ip);
919 R32(esp, sp);
920
921 case offsetof(struct user32, regs.orig_eax):
922 /*
923 * Warning: bizarre corner case fixup here. A 32-bit
924 * debugger setting orig_eax to -1 wants to disable
925 * syscall restart. Make sure that the syscall
926 * restart code sign-extends orig_ax. Also make sure
927 * we interpret the -ERESTART* codes correctly if
928 * loaded into regs->ax in case the task is not
929 * actually still sitting at the exit from a 32-bit
930 * syscall with TS_COMPAT still set.
931 */
932 regs->orig_ax = value;
933 if (syscall_get_nr(child, regs) != -1)
934 child->thread_info.status |= TS_I386_REGS_POKED;
935 break;
936
937 case offsetof(struct user32, regs.eflags):
938 return set_flags(child, value);
939
940 case offsetof(struct user32, u_debugreg[0]) ...
941 offsetof(struct user32, u_debugreg[7]):
942 regno -= offsetof(struct user32, u_debugreg[0]);
943 return ptrace_set_debugreg(child, regno / 4, value);
944
945 default:
946 if (regno > sizeof(struct user32) || (regno & 3))
947 return -EIO;
948
949 /*
950 * Other dummy fields in the virtual user structure
951 * are ignored
952 */
953 break;
954 }
955 return 0;
956}
957
958#undef R32
959#undef SEG32
960
961#define R32(l,q) \
962 case offsetof(struct user32, regs.l): \
963 *val = regs->q; break
964
965#define SEG32(rs) \
966 case offsetof(struct user32, regs.rs): \
967 *val = get_segment_reg(child, \
968 offsetof(struct user_regs_struct, rs)); \
969 break
970
971static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
972{
973 struct pt_regs *regs = task_pt_regs(child);
974
975 switch (regno) {
976
977 SEG32(ds);
978 SEG32(es);
979 SEG32(fs);
980 SEG32(gs);
981
982 R32(cs, cs);
983 R32(ss, ss);
984 R32(ebx, bx);
985 R32(ecx, cx);
986 R32(edx, dx);
987 R32(edi, di);
988 R32(esi, si);
989 R32(ebp, bp);
990 R32(eax, ax);
991 R32(orig_eax, orig_ax);
992 R32(eip, ip);
993 R32(esp, sp);
994
995 case offsetof(struct user32, regs.eflags):
996 *val = get_flags(child);
997 break;
998
999 case offsetof(struct user32, u_debugreg[0]) ...
1000 offsetof(struct user32, u_debugreg[7]):
1001 regno -= offsetof(struct user32, u_debugreg[0]);
1002 *val = ptrace_get_debugreg(child, regno / 4);
1003 break;
1004
1005 default:
1006 if (regno > sizeof(struct user32) || (regno & 3))
1007 return -EIO;
1008
1009 /*
1010 * Other dummy fields in the virtual user structure
1011 * are ignored
1012 */
1013 *val = 0;
1014 break;
1015 }
1016 return 0;
1017}
1018
1019#undef R32
1020#undef SEG32
1021
1022static int genregs32_get(struct task_struct *target,
1023 const struct user_regset *regset,
1024 struct membuf to)
1025{
1026 int reg;
1027
1028 for (reg = 0; to.left; reg++) {
1029 u32 val;
1030 getreg32(target, reg * 4, &val);
1031 membuf_store(&to, val);
1032 }
1033 return 0;
1034}
1035
1036static int genregs32_set(struct task_struct *target,
1037 const struct user_regset *regset,
1038 unsigned int pos, unsigned int count,
1039 const void *kbuf, const void __user *ubuf)
1040{
1041 int ret = 0;
1042 if (kbuf) {
1043 const compat_ulong_t *k = kbuf;
1044 while (count >= sizeof(*k) && !ret) {
1045 ret = putreg32(target, pos, *k++);
1046 count -= sizeof(*k);
1047 pos += sizeof(*k);
1048 }
1049 } else {
1050 const compat_ulong_t __user *u = ubuf;
1051 while (count >= sizeof(*u) && !ret) {
1052 compat_ulong_t word;
1053 ret = __get_user(word, u++);
1054 if (ret)
1055 break;
1056 ret = putreg32(target, pos, word);
1057 count -= sizeof(*u);
1058 pos += sizeof(*u);
1059 }
1060 }
1061 return ret;
1062}
1063
1064static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1065 compat_ulong_t caddr, compat_ulong_t cdata)
1066{
1067 unsigned long addr = caddr;
1068 unsigned long data = cdata;
1069 void __user *datap = compat_ptr(data);
1070 int ret;
1071 __u32 val;
1072
1073 switch (request) {
1074 case PTRACE_PEEKUSR:
1075 ret = getreg32(child, addr, &val);
1076 if (ret == 0)
1077 ret = put_user(val, (__u32 __user *)datap);
1078 break;
1079
1080 case PTRACE_POKEUSR:
1081 ret = putreg32(child, addr, data);
1082 break;
1083
1084 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1085 return copy_regset_to_user(child, &user_x86_32_view,
1086 REGSET_GENERAL,
1087 0, sizeof(struct user_regs_struct32),
1088 datap);
1089
1090 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1091 return copy_regset_from_user(child, &user_x86_32_view,
1092 REGSET_GENERAL, 0,
1093 sizeof(struct user_regs_struct32),
1094 datap);
1095
1096 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1097 return copy_regset_to_user(child, &user_x86_32_view,
1098 REGSET_FP, 0,
1099 sizeof(struct user_i387_ia32_struct),
1100 datap);
1101
1102 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1103 return copy_regset_from_user(
1104 child, &user_x86_32_view, REGSET_FP,
1105 0, sizeof(struct user_i387_ia32_struct), datap);
1106
1107 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1108 return copy_regset_to_user(child, &user_x86_32_view,
1109 REGSET32_XFP, 0,
1110 sizeof(struct user32_fxsr_struct),
1111 datap);
1112
1113 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1114 return copy_regset_from_user(child, &user_x86_32_view,
1115 REGSET32_XFP, 0,
1116 sizeof(struct user32_fxsr_struct),
1117 datap);
1118
1119 case PTRACE_GET_THREAD_AREA:
1120 case PTRACE_SET_THREAD_AREA:
1121 return arch_ptrace(child, request, addr, data);
1122
1123 default:
1124 return compat_ptrace_request(child, request, addr, data);
1125 }
1126
1127 return ret;
1128}
1129#endif /* CONFIG_IA32_EMULATION */
1130
1131#ifdef CONFIG_X86_X32_ABI
1132static long x32_arch_ptrace(struct task_struct *child,
1133 compat_long_t request, compat_ulong_t caddr,
1134 compat_ulong_t cdata)
1135{
1136 unsigned long addr = caddr;
1137 unsigned long data = cdata;
1138 void __user *datap = compat_ptr(data);
1139 int ret;
1140
1141 switch (request) {
1142 /* Read 32bits at location addr in the USER area. Only allow
1143 to return the lower 32bits of segment and debug registers. */
1144 case PTRACE_PEEKUSR: {
1145 u32 tmp;
1146
1147 ret = -EIO;
1148 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1149 addr < offsetof(struct user_regs_struct, cs))
1150 break;
1151
1152 tmp = 0; /* Default return condition */
1153 if (addr < sizeof(struct user_regs_struct))
1154 tmp = getreg(child, addr);
1155 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1156 addr <= offsetof(struct user, u_debugreg[7])) {
1157 addr -= offsetof(struct user, u_debugreg[0]);
1158 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1159 }
1160 ret = put_user(tmp, (__u32 __user *)datap);
1161 break;
1162 }
1163
1164 /* Write the word at location addr in the USER area. Only allow
1165 to update segment and debug registers with the upper 32bits
1166 zero-extended. */
1167 case PTRACE_POKEUSR:
1168 ret = -EIO;
1169 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1170 addr < offsetof(struct user_regs_struct, cs))
1171 break;
1172
1173 if (addr < sizeof(struct user_regs_struct))
1174 ret = putreg(child, addr, data);
1175 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1176 addr <= offsetof(struct user, u_debugreg[7])) {
1177 addr -= offsetof(struct user, u_debugreg[0]);
1178 ret = ptrace_set_debugreg(child,
1179 addr / sizeof(data), data);
1180 }
1181 break;
1182
1183 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1184 return copy_regset_to_user(child,
1185 &user_x86_64_view,
1186 REGSET_GENERAL,
1187 0, sizeof(struct user_regs_struct),
1188 datap);
1189
1190 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1191 return copy_regset_from_user(child,
1192 &user_x86_64_view,
1193 REGSET_GENERAL,
1194 0, sizeof(struct user_regs_struct),
1195 datap);
1196
1197 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1198 return copy_regset_to_user(child,
1199 &user_x86_64_view,
1200 REGSET_FP,
1201 0, sizeof(struct user_i387_struct),
1202 datap);
1203
1204 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1205 return copy_regset_from_user(child,
1206 &user_x86_64_view,
1207 REGSET_FP,
1208 0, sizeof(struct user_i387_struct),
1209 datap);
1210
1211 default:
1212 return compat_ptrace_request(child, request, addr, data);
1213 }
1214
1215 return ret;
1216}
1217#endif
1218
1219#ifdef CONFIG_COMPAT
1220long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1221 compat_ulong_t caddr, compat_ulong_t cdata)
1222{
1223#ifdef CONFIG_X86_X32_ABI
1224 if (!in_ia32_syscall())
1225 return x32_arch_ptrace(child, request, caddr, cdata);
1226#endif
1227#ifdef CONFIG_IA32_EMULATION
1228 return ia32_arch_ptrace(child, request, caddr, cdata);
1229#else
1230 return 0;
1231#endif
1232}
1233#endif /* CONFIG_COMPAT */
1234
1235#ifdef CONFIG_X86_64
1236
1237static struct user_regset x86_64_regsets[] __ro_after_init = {
1238 [REGSET64_GENERAL] = {
1239 .core_note_type = NT_PRSTATUS,
1240 .n = sizeof(struct user_regs_struct) / sizeof(long),
1241 .size = sizeof(long),
1242 .align = sizeof(long),
1243 .regset_get = genregs_get,
1244 .set = genregs_set
1245 },
1246 [REGSET64_FP] = {
1247 .core_note_type = NT_PRFPREG,
1248 .n = sizeof(struct fxregs_state) / sizeof(long),
1249 .size = sizeof(long),
1250 .align = sizeof(long),
1251 .active = regset_xregset_fpregs_active,
1252 .regset_get = xfpregs_get,
1253 .set = xfpregs_set
1254 },
1255 [REGSET64_XSTATE] = {
1256 .core_note_type = NT_X86_XSTATE,
1257 .size = sizeof(u64),
1258 .align = sizeof(u64),
1259 .active = xstateregs_active,
1260 .regset_get = xstateregs_get,
1261 .set = xstateregs_set
1262 },
1263 [REGSET64_IOPERM] = {
1264 .core_note_type = NT_386_IOPERM,
1265 .n = IO_BITMAP_LONGS,
1266 .size = sizeof(long),
1267 .align = sizeof(long),
1268 .active = ioperm_active,
1269 .regset_get = ioperm_get
1270 },
1271#ifdef CONFIG_X86_USER_SHADOW_STACK
1272 [REGSET64_SSP] = {
1273 .core_note_type = NT_X86_SHSTK,
1274 .n = 1,
1275 .size = sizeof(u64),
1276 .align = sizeof(u64),
1277 .active = ssp_active,
1278 .regset_get = ssp_get,
1279 .set = ssp_set
1280 },
1281#endif
1282};
1283
1284static const struct user_regset_view user_x86_64_view = {
1285 .name = "x86_64", .e_machine = EM_X86_64,
1286 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1287};
1288
1289#else /* CONFIG_X86_32 */
1290
1291#define user_regs_struct32 user_regs_struct
1292#define genregs32_get genregs_get
1293#define genregs32_set genregs_set
1294
1295#endif /* CONFIG_X86_64 */
1296
1297#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1298static struct user_regset x86_32_regsets[] __ro_after_init = {
1299 [REGSET32_GENERAL] = {
1300 .core_note_type = NT_PRSTATUS,
1301 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1302 .size = sizeof(u32),
1303 .align = sizeof(u32),
1304 .regset_get = genregs32_get,
1305 .set = genregs32_set
1306 },
1307 [REGSET32_FP] = {
1308 .core_note_type = NT_PRFPREG,
1309 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1310 .size = sizeof(u32),
1311 .align = sizeof(u32),
1312 .active = regset_fpregs_active,
1313 .regset_get = fpregs_get,
1314 .set = fpregs_set
1315 },
1316 [REGSET32_XFP] = {
1317 .core_note_type = NT_PRXFPREG,
1318 .n = sizeof(struct fxregs_state) / sizeof(u32),
1319 .size = sizeof(u32),
1320 .align = sizeof(u32),
1321 .active = regset_xregset_fpregs_active,
1322 .regset_get = xfpregs_get,
1323 .set = xfpregs_set
1324 },
1325 [REGSET32_XSTATE] = {
1326 .core_note_type = NT_X86_XSTATE,
1327 .size = sizeof(u64),
1328 .align = sizeof(u64),
1329 .active = xstateregs_active,
1330 .regset_get = xstateregs_get,
1331 .set = xstateregs_set
1332 },
1333 [REGSET32_TLS] = {
1334 .core_note_type = NT_386_TLS,
1335 .n = GDT_ENTRY_TLS_ENTRIES,
1336 .bias = GDT_ENTRY_TLS_MIN,
1337 .size = sizeof(struct user_desc),
1338 .align = sizeof(struct user_desc),
1339 .active = regset_tls_active,
1340 .regset_get = regset_tls_get,
1341 .set = regset_tls_set
1342 },
1343 [REGSET32_IOPERM] = {
1344 .core_note_type = NT_386_IOPERM,
1345 .n = IO_BITMAP_BYTES / sizeof(u32),
1346 .size = sizeof(u32),
1347 .align = sizeof(u32),
1348 .active = ioperm_active,
1349 .regset_get = ioperm_get
1350 },
1351};
1352
1353static const struct user_regset_view user_x86_32_view = {
1354 .name = "i386", .e_machine = EM_386,
1355 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1356};
1357#endif
1358
1359/*
1360 * This represents bytes 464..511 in the memory layout exported through
1361 * the REGSET_XSTATE interface.
1362 */
1363u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1364
1365void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1366{
1367#ifdef CONFIG_X86_64
1368 x86_64_regsets[REGSET64_XSTATE].n = size / sizeof(u64);
1369#endif
1370#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1371 x86_32_regsets[REGSET32_XSTATE].n = size / sizeof(u64);
1372#endif
1373 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1374}
1375
1376/*
1377 * This is used by the core dump code to decide which regset to dump. The
1378 * core dump code writes out the resulting .e_machine and the corresponding
1379 * regsets. This is suboptimal if the task is messing around with its CS.L
1380 * field, but at worst the core dump will end up missing some information.
1381 *
1382 * Unfortunately, it is also used by the broken PTRACE_GETREGSET and
1383 * PTRACE_SETREGSET APIs. These APIs look at the .regsets field but have
1384 * no way to make sure that the e_machine they use matches the caller's
1385 * expectations. The result is that the data format returned by
1386 * PTRACE_GETREGSET depends on the returned CS field (and even the offset
1387 * of the returned CS field depends on its value!) and the data format
1388 * accepted by PTRACE_SETREGSET is determined by the old CS value. The
1389 * upshot is that it is basically impossible to use these APIs correctly.
1390 *
1391 * The best way to fix it in the long run would probably be to add new
1392 * improved ptrace() APIs to read and write registers reliably, possibly by
1393 * allowing userspace to select the ELF e_machine variant that they expect.
1394 */
1395const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1396{
1397#ifdef CONFIG_IA32_EMULATION
1398 if (!user_64bit_mode(task_pt_regs(task)))
1399#endif
1400#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1401 return &user_x86_32_view;
1402#endif
1403#ifdef CONFIG_X86_64
1404 return &user_x86_64_view;
1405#endif
1406}
1407
1408void send_sigtrap(struct pt_regs *regs, int error_code, int si_code)
1409{
1410 struct task_struct *tsk = current;
1411
1412 tsk->thread.trap_nr = X86_TRAP_DB;
1413 tsk->thread.error_code = error_code;
1414
1415 /* Send us the fake SIGTRAP */
1416 force_sig_fault(SIGTRAP, si_code,
1417 user_mode(regs) ? (void __user *)regs->ip : NULL);
1418}
1419
1420void user_single_step_report(struct pt_regs *regs)
1421{
1422 send_sigtrap(regs, 0, TRAP_BRKPT);
1423}
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/regset.h>
15#include <linux/tracehook.h>
16#include <linux/user.h>
17#include <linux/elf.h>
18#include <linux/security.h>
19#include <linux/audit.h>
20#include <linux/seccomp.h>
21#include <linux/signal.h>
22#include <linux/perf_event.h>
23#include <linux/hw_breakpoint.h>
24
25#include <asm/uaccess.h>
26#include <asm/pgtable.h>
27#include <asm/processor.h>
28#include <asm/i387.h>
29#include <asm/fpu-internal.h>
30#include <asm/debugreg.h>
31#include <asm/ldt.h>
32#include <asm/desc.h>
33#include <asm/prctl.h>
34#include <asm/proto.h>
35#include <asm/hw_breakpoint.h>
36#include <asm/traps.h>
37
38#include "tls.h"
39
40#define CREATE_TRACE_POINTS
41#include <trace/events/syscalls.h>
42
43enum x86_regset {
44 REGSET_GENERAL,
45 REGSET_FP,
46 REGSET_XFP,
47 REGSET_IOPERM64 = REGSET_XFP,
48 REGSET_XSTATE,
49 REGSET_TLS,
50 REGSET_IOPERM32,
51};
52
53struct pt_regs_offset {
54 const char *name;
55 int offset;
56};
57
58#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
59#define REG_OFFSET_END {.name = NULL, .offset = 0}
60
61static const struct pt_regs_offset regoffset_table[] = {
62#ifdef CONFIG_X86_64
63 REG_OFFSET_NAME(r15),
64 REG_OFFSET_NAME(r14),
65 REG_OFFSET_NAME(r13),
66 REG_OFFSET_NAME(r12),
67 REG_OFFSET_NAME(r11),
68 REG_OFFSET_NAME(r10),
69 REG_OFFSET_NAME(r9),
70 REG_OFFSET_NAME(r8),
71#endif
72 REG_OFFSET_NAME(bx),
73 REG_OFFSET_NAME(cx),
74 REG_OFFSET_NAME(dx),
75 REG_OFFSET_NAME(si),
76 REG_OFFSET_NAME(di),
77 REG_OFFSET_NAME(bp),
78 REG_OFFSET_NAME(ax),
79#ifdef CONFIG_X86_32
80 REG_OFFSET_NAME(ds),
81 REG_OFFSET_NAME(es),
82 REG_OFFSET_NAME(fs),
83 REG_OFFSET_NAME(gs),
84#endif
85 REG_OFFSET_NAME(orig_ax),
86 REG_OFFSET_NAME(ip),
87 REG_OFFSET_NAME(cs),
88 REG_OFFSET_NAME(flags),
89 REG_OFFSET_NAME(sp),
90 REG_OFFSET_NAME(ss),
91 REG_OFFSET_END,
92};
93
94/**
95 * regs_query_register_offset() - query register offset from its name
96 * @name: the name of a register
97 *
98 * regs_query_register_offset() returns the offset of a register in struct
99 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
100 */
101int regs_query_register_offset(const char *name)
102{
103 const struct pt_regs_offset *roff;
104 for (roff = regoffset_table; roff->name != NULL; roff++)
105 if (!strcmp(roff->name, name))
106 return roff->offset;
107 return -EINVAL;
108}
109
110/**
111 * regs_query_register_name() - query register name from its offset
112 * @offset: the offset of a register in struct pt_regs.
113 *
114 * regs_query_register_name() returns the name of a register from its
115 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
116 */
117const char *regs_query_register_name(unsigned int offset)
118{
119 const struct pt_regs_offset *roff;
120 for (roff = regoffset_table; roff->name != NULL; roff++)
121 if (roff->offset == offset)
122 return roff->name;
123 return NULL;
124}
125
126static const int arg_offs_table[] = {
127#ifdef CONFIG_X86_32
128 [0] = offsetof(struct pt_regs, ax),
129 [1] = offsetof(struct pt_regs, dx),
130 [2] = offsetof(struct pt_regs, cx)
131#else /* CONFIG_X86_64 */
132 [0] = offsetof(struct pt_regs, di),
133 [1] = offsetof(struct pt_regs, si),
134 [2] = offsetof(struct pt_regs, dx),
135 [3] = offsetof(struct pt_regs, cx),
136 [4] = offsetof(struct pt_regs, r8),
137 [5] = offsetof(struct pt_regs, r9)
138#endif
139};
140
141/*
142 * does not yet catch signals sent when the child dies.
143 * in exit.c or in signal.c.
144 */
145
146/*
147 * Determines which flags the user has access to [1 = access, 0 = no access].
148 */
149#define FLAG_MASK_32 ((unsigned long) \
150 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
151 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
152 X86_EFLAGS_SF | X86_EFLAGS_TF | \
153 X86_EFLAGS_DF | X86_EFLAGS_OF | \
154 X86_EFLAGS_RF | X86_EFLAGS_AC))
155
156/*
157 * Determines whether a value may be installed in a segment register.
158 */
159static inline bool invalid_selector(u16 value)
160{
161 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
162}
163
164#ifdef CONFIG_X86_32
165
166#define FLAG_MASK FLAG_MASK_32
167
168static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
169{
170 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
171 return ®s->bx + (regno >> 2);
172}
173
174static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
175{
176 /*
177 * Returning the value truncates it to 16 bits.
178 */
179 unsigned int retval;
180 if (offset != offsetof(struct user_regs_struct, gs))
181 retval = *pt_regs_access(task_pt_regs(task), offset);
182 else {
183 if (task == current)
184 retval = get_user_gs(task_pt_regs(task));
185 else
186 retval = task_user_gs(task);
187 }
188 return retval;
189}
190
191static int set_segment_reg(struct task_struct *task,
192 unsigned long offset, u16 value)
193{
194 /*
195 * The value argument was already truncated to 16 bits.
196 */
197 if (invalid_selector(value))
198 return -EIO;
199
200 /*
201 * For %cs and %ss we cannot permit a null selector.
202 * We can permit a bogus selector as long as it has USER_RPL.
203 * Null selectors are fine for other segment registers, but
204 * we will never get back to user mode with invalid %cs or %ss
205 * and will take the trap in iret instead. Much code relies
206 * on user_mode() to distinguish a user trap frame (which can
207 * safely use invalid selectors) from a kernel trap frame.
208 */
209 switch (offset) {
210 case offsetof(struct user_regs_struct, cs):
211 case offsetof(struct user_regs_struct, ss):
212 if (unlikely(value == 0))
213 return -EIO;
214
215 default:
216 *pt_regs_access(task_pt_regs(task), offset) = value;
217 break;
218
219 case offsetof(struct user_regs_struct, gs):
220 if (task == current)
221 set_user_gs(task_pt_regs(task), value);
222 else
223 task_user_gs(task) = value;
224 }
225
226 return 0;
227}
228
229#else /* CONFIG_X86_64 */
230
231#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
232
233static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
234{
235 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
236 return ®s->r15 + (offset / sizeof(regs->r15));
237}
238
239static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
240{
241 /*
242 * Returning the value truncates it to 16 bits.
243 */
244 unsigned int seg;
245
246 switch (offset) {
247 case offsetof(struct user_regs_struct, fs):
248 if (task == current) {
249 /* Older gas can't assemble movq %?s,%r?? */
250 asm("movl %%fs,%0" : "=r" (seg));
251 return seg;
252 }
253 return task->thread.fsindex;
254 case offsetof(struct user_regs_struct, gs):
255 if (task == current) {
256 asm("movl %%gs,%0" : "=r" (seg));
257 return seg;
258 }
259 return task->thread.gsindex;
260 case offsetof(struct user_regs_struct, ds):
261 if (task == current) {
262 asm("movl %%ds,%0" : "=r" (seg));
263 return seg;
264 }
265 return task->thread.ds;
266 case offsetof(struct user_regs_struct, es):
267 if (task == current) {
268 asm("movl %%es,%0" : "=r" (seg));
269 return seg;
270 }
271 return task->thread.es;
272
273 case offsetof(struct user_regs_struct, cs):
274 case offsetof(struct user_regs_struct, ss):
275 break;
276 }
277 return *pt_regs_access(task_pt_regs(task), offset);
278}
279
280static int set_segment_reg(struct task_struct *task,
281 unsigned long offset, u16 value)
282{
283 /*
284 * The value argument was already truncated to 16 bits.
285 */
286 if (invalid_selector(value))
287 return -EIO;
288
289 switch (offset) {
290 case offsetof(struct user_regs_struct,fs):
291 /*
292 * If this is setting fs as for normal 64-bit use but
293 * setting fs_base has implicitly changed it, leave it.
294 */
295 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
296 task->thread.fs != 0) ||
297 (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
298 task->thread.fs == 0))
299 break;
300 task->thread.fsindex = value;
301 if (task == current)
302 loadsegment(fs, task->thread.fsindex);
303 break;
304 case offsetof(struct user_regs_struct,gs):
305 /*
306 * If this is setting gs as for normal 64-bit use but
307 * setting gs_base has implicitly changed it, leave it.
308 */
309 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
310 task->thread.gs != 0) ||
311 (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
312 task->thread.gs == 0))
313 break;
314 task->thread.gsindex = value;
315 if (task == current)
316 load_gs_index(task->thread.gsindex);
317 break;
318 case offsetof(struct user_regs_struct,ds):
319 task->thread.ds = value;
320 if (task == current)
321 loadsegment(ds, task->thread.ds);
322 break;
323 case offsetof(struct user_regs_struct,es):
324 task->thread.es = value;
325 if (task == current)
326 loadsegment(es, task->thread.es);
327 break;
328
329 /*
330 * Can't actually change these in 64-bit mode.
331 */
332 case offsetof(struct user_regs_struct,cs):
333 if (unlikely(value == 0))
334 return -EIO;
335#ifdef CONFIG_IA32_EMULATION
336 if (test_tsk_thread_flag(task, TIF_IA32))
337 task_pt_regs(task)->cs = value;
338#endif
339 break;
340 case offsetof(struct user_regs_struct,ss):
341 if (unlikely(value == 0))
342 return -EIO;
343#ifdef CONFIG_IA32_EMULATION
344 if (test_tsk_thread_flag(task, TIF_IA32))
345 task_pt_regs(task)->ss = value;
346#endif
347 break;
348 }
349
350 return 0;
351}
352
353#endif /* CONFIG_X86_32 */
354
355static unsigned long get_flags(struct task_struct *task)
356{
357 unsigned long retval = task_pt_regs(task)->flags;
358
359 /*
360 * If the debugger set TF, hide it from the readout.
361 */
362 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
363 retval &= ~X86_EFLAGS_TF;
364
365 return retval;
366}
367
368static int set_flags(struct task_struct *task, unsigned long value)
369{
370 struct pt_regs *regs = task_pt_regs(task);
371
372 /*
373 * If the user value contains TF, mark that
374 * it was not "us" (the debugger) that set it.
375 * If not, make sure it stays set if we had.
376 */
377 if (value & X86_EFLAGS_TF)
378 clear_tsk_thread_flag(task, TIF_FORCED_TF);
379 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
380 value |= X86_EFLAGS_TF;
381
382 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
383
384 return 0;
385}
386
387static int putreg(struct task_struct *child,
388 unsigned long offset, unsigned long value)
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 set_segment_reg(child, offset, value);
398
399 case offsetof(struct user_regs_struct, flags):
400 return set_flags(child, value);
401
402#ifdef CONFIG_X86_64
403 case offsetof(struct user_regs_struct,fs_base):
404 if (value >= TASK_SIZE_OF(child))
405 return -EIO;
406 /*
407 * When changing the segment base, use do_arch_prctl
408 * to set either thread.fs or thread.fsindex and the
409 * corresponding GDT slot.
410 */
411 if (child->thread.fs != value)
412 return do_arch_prctl(child, ARCH_SET_FS, value);
413 return 0;
414 case offsetof(struct user_regs_struct,gs_base):
415 /*
416 * Exactly the same here as the %fs handling above.
417 */
418 if (value >= TASK_SIZE_OF(child))
419 return -EIO;
420 if (child->thread.gs != value)
421 return do_arch_prctl(child, ARCH_SET_GS, value);
422 return 0;
423#endif
424 }
425
426 *pt_regs_access(task_pt_regs(child), offset) = value;
427 return 0;
428}
429
430static unsigned long getreg(struct task_struct *task, unsigned long offset)
431{
432 switch (offset) {
433 case offsetof(struct user_regs_struct, cs):
434 case offsetof(struct user_regs_struct, ds):
435 case offsetof(struct user_regs_struct, es):
436 case offsetof(struct user_regs_struct, fs):
437 case offsetof(struct user_regs_struct, gs):
438 case offsetof(struct user_regs_struct, ss):
439 return get_segment_reg(task, offset);
440
441 case offsetof(struct user_regs_struct, flags):
442 return get_flags(task);
443
444#ifdef CONFIG_X86_64
445 case offsetof(struct user_regs_struct, fs_base): {
446 /*
447 * do_arch_prctl may have used a GDT slot instead of
448 * the MSR. To userland, it appears the same either
449 * way, except the %fs segment selector might not be 0.
450 */
451 unsigned int seg = task->thread.fsindex;
452 if (task->thread.fs != 0)
453 return task->thread.fs;
454 if (task == current)
455 asm("movl %%fs,%0" : "=r" (seg));
456 if (seg != FS_TLS_SEL)
457 return 0;
458 return get_desc_base(&task->thread.tls_array[FS_TLS]);
459 }
460 case offsetof(struct user_regs_struct, gs_base): {
461 /*
462 * Exactly the same here as the %fs handling above.
463 */
464 unsigned int seg = task->thread.gsindex;
465 if (task->thread.gs != 0)
466 return task->thread.gs;
467 if (task == current)
468 asm("movl %%gs,%0" : "=r" (seg));
469 if (seg != GS_TLS_SEL)
470 return 0;
471 return get_desc_base(&task->thread.tls_array[GS_TLS]);
472 }
473#endif
474 }
475
476 return *pt_regs_access(task_pt_regs(task), offset);
477}
478
479static int genregs_get(struct task_struct *target,
480 const struct user_regset *regset,
481 unsigned int pos, unsigned int count,
482 void *kbuf, void __user *ubuf)
483{
484 if (kbuf) {
485 unsigned long *k = kbuf;
486 while (count >= sizeof(*k)) {
487 *k++ = getreg(target, pos);
488 count -= sizeof(*k);
489 pos += sizeof(*k);
490 }
491 } else {
492 unsigned long __user *u = ubuf;
493 while (count >= sizeof(*u)) {
494 if (__put_user(getreg(target, pos), u++))
495 return -EFAULT;
496 count -= sizeof(*u);
497 pos += sizeof(*u);
498 }
499 }
500
501 return 0;
502}
503
504static int genregs_set(struct task_struct *target,
505 const struct user_regset *regset,
506 unsigned int pos, unsigned int count,
507 const void *kbuf, const void __user *ubuf)
508{
509 int ret = 0;
510 if (kbuf) {
511 const unsigned long *k = kbuf;
512 while (count >= sizeof(*k) && !ret) {
513 ret = putreg(target, pos, *k++);
514 count -= sizeof(*k);
515 pos += sizeof(*k);
516 }
517 } else {
518 const unsigned long __user *u = ubuf;
519 while (count >= sizeof(*u) && !ret) {
520 unsigned long word;
521 ret = __get_user(word, u++);
522 if (ret)
523 break;
524 ret = putreg(target, pos, word);
525 count -= sizeof(*u);
526 pos += sizeof(*u);
527 }
528 }
529 return ret;
530}
531
532static void ptrace_triggered(struct perf_event *bp,
533 struct perf_sample_data *data,
534 struct pt_regs *regs)
535{
536 int i;
537 struct thread_struct *thread = &(current->thread);
538
539 /*
540 * Store in the virtual DR6 register the fact that the breakpoint
541 * was hit so the thread's debugger will see it.
542 */
543 for (i = 0; i < HBP_NUM; i++) {
544 if (thread->ptrace_bps[i] == bp)
545 break;
546 }
547
548 thread->debugreg6 |= (DR_TRAP0 << i);
549}
550
551/*
552 * Walk through every ptrace breakpoints for this thread and
553 * build the dr7 value on top of their attributes.
554 *
555 */
556static unsigned long ptrace_get_dr7(struct perf_event *bp[])
557{
558 int i;
559 int dr7 = 0;
560 struct arch_hw_breakpoint *info;
561
562 for (i = 0; i < HBP_NUM; i++) {
563 if (bp[i] && !bp[i]->attr.disabled) {
564 info = counter_arch_bp(bp[i]);
565 dr7 |= encode_dr7(i, info->len, info->type);
566 }
567 }
568
569 return dr7;
570}
571
572static int
573ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
574 struct task_struct *tsk, int disabled)
575{
576 int err;
577 int gen_len, gen_type;
578 struct perf_event_attr attr;
579
580 /*
581 * We should have at least an inactive breakpoint at this
582 * slot. It means the user is writing dr7 without having
583 * written the address register first
584 */
585 if (!bp)
586 return -EINVAL;
587
588 err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
589 if (err)
590 return err;
591
592 attr = bp->attr;
593 attr.bp_len = gen_len;
594 attr.bp_type = gen_type;
595 attr.disabled = disabled;
596
597 return modify_user_hw_breakpoint(bp, &attr);
598}
599
600/*
601 * Handle ptrace writes to debug register 7.
602 */
603static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
604{
605 struct thread_struct *thread = &(tsk->thread);
606 unsigned long old_dr7;
607 int i, orig_ret = 0, rc = 0;
608 int enabled, second_pass = 0;
609 unsigned len, type;
610 struct perf_event *bp;
611
612 if (ptrace_get_breakpoints(tsk) < 0)
613 return -ESRCH;
614
615 data &= ~DR_CONTROL_RESERVED;
616 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
617restore:
618 /*
619 * Loop through all the hardware breakpoints, making the
620 * appropriate changes to each.
621 */
622 for (i = 0; i < HBP_NUM; i++) {
623 enabled = decode_dr7(data, i, &len, &type);
624 bp = thread->ptrace_bps[i];
625
626 if (!enabled) {
627 if (bp) {
628 /*
629 * Don't unregister the breakpoints right-away,
630 * unless all register_user_hw_breakpoint()
631 * requests have succeeded. This prevents
632 * any window of opportunity for debug
633 * register grabbing by other users.
634 */
635 if (!second_pass)
636 continue;
637
638 rc = ptrace_modify_breakpoint(bp, len, type,
639 tsk, 1);
640 if (rc)
641 break;
642 }
643 continue;
644 }
645
646 rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0);
647 if (rc)
648 break;
649 }
650 /*
651 * Make a second pass to free the remaining unused breakpoints
652 * or to restore the original breakpoints if an error occurred.
653 */
654 if (!second_pass) {
655 second_pass = 1;
656 if (rc < 0) {
657 orig_ret = rc;
658 data = old_dr7;
659 }
660 goto restore;
661 }
662
663 ptrace_put_breakpoints(tsk);
664
665 return ((orig_ret < 0) ? orig_ret : rc);
666}
667
668/*
669 * Handle PTRACE_PEEKUSR calls for the debug register area.
670 */
671static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
672{
673 struct thread_struct *thread = &(tsk->thread);
674 unsigned long val = 0;
675
676 if (n < HBP_NUM) {
677 struct perf_event *bp;
678
679 if (ptrace_get_breakpoints(tsk) < 0)
680 return -ESRCH;
681
682 bp = thread->ptrace_bps[n];
683 if (!bp)
684 val = 0;
685 else
686 val = bp->hw.info.address;
687
688 ptrace_put_breakpoints(tsk);
689 } else if (n == 6) {
690 val = thread->debugreg6;
691 } else if (n == 7) {
692 val = thread->ptrace_dr7;
693 }
694 return val;
695}
696
697static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
698 unsigned long addr)
699{
700 struct perf_event *bp;
701 struct thread_struct *t = &tsk->thread;
702 struct perf_event_attr attr;
703 int err = 0;
704
705 if (ptrace_get_breakpoints(tsk) < 0)
706 return -ESRCH;
707
708 if (!t->ptrace_bps[nr]) {
709 ptrace_breakpoint_init(&attr);
710 /*
711 * Put stub len and type to register (reserve) an inactive but
712 * correct bp
713 */
714 attr.bp_addr = addr;
715 attr.bp_len = HW_BREAKPOINT_LEN_1;
716 attr.bp_type = HW_BREAKPOINT_W;
717 attr.disabled = 1;
718
719 bp = register_user_hw_breakpoint(&attr, ptrace_triggered,
720 NULL, tsk);
721
722 /*
723 * CHECKME: the previous code returned -EIO if the addr wasn't
724 * a valid task virtual addr. The new one will return -EINVAL in
725 * this case.
726 * -EINVAL may be what we want for in-kernel breakpoints users,
727 * but -EIO looks better for ptrace, since we refuse a register
728 * writing for the user. And anyway this is the previous
729 * behaviour.
730 */
731 if (IS_ERR(bp)) {
732 err = PTR_ERR(bp);
733 goto put;
734 }
735
736 t->ptrace_bps[nr] = bp;
737 } else {
738 bp = t->ptrace_bps[nr];
739
740 attr = bp->attr;
741 attr.bp_addr = addr;
742 err = modify_user_hw_breakpoint(bp, &attr);
743 }
744
745put:
746 ptrace_put_breakpoints(tsk);
747 return err;
748}
749
750/*
751 * Handle PTRACE_POKEUSR calls for the debug register area.
752 */
753static int ptrace_set_debugreg(struct task_struct *tsk, int n,
754 unsigned long val)
755{
756 struct thread_struct *thread = &(tsk->thread);
757 int rc = 0;
758
759 /* There are no DR4 or DR5 registers */
760 if (n == 4 || n == 5)
761 return -EIO;
762
763 if (n == 6) {
764 thread->debugreg6 = val;
765 goto ret_path;
766 }
767 if (n < HBP_NUM) {
768 rc = ptrace_set_breakpoint_addr(tsk, n, val);
769 if (rc)
770 return rc;
771 }
772 /* All that's left is DR7 */
773 if (n == 7) {
774 rc = ptrace_write_dr7(tsk, val);
775 if (!rc)
776 thread->ptrace_dr7 = val;
777 }
778
779ret_path:
780 return rc;
781}
782
783/*
784 * These access the current or another (stopped) task's io permission
785 * bitmap for debugging or core dump.
786 */
787static int ioperm_active(struct task_struct *target,
788 const struct user_regset *regset)
789{
790 return target->thread.io_bitmap_max / regset->size;
791}
792
793static int ioperm_get(struct task_struct *target,
794 const struct user_regset *regset,
795 unsigned int pos, unsigned int count,
796 void *kbuf, void __user *ubuf)
797{
798 if (!target->thread.io_bitmap_ptr)
799 return -ENXIO;
800
801 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
802 target->thread.io_bitmap_ptr,
803 0, IO_BITMAP_BYTES);
804}
805
806/*
807 * Called by kernel/ptrace.c when detaching..
808 *
809 * Make sure the single step bit is not set.
810 */
811void ptrace_disable(struct task_struct *child)
812{
813 user_disable_single_step(child);
814#ifdef TIF_SYSCALL_EMU
815 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
816#endif
817}
818
819#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
820static const struct user_regset_view user_x86_32_view; /* Initialized below. */
821#endif
822
823long arch_ptrace(struct task_struct *child, long request,
824 unsigned long addr, unsigned long data)
825{
826 int ret;
827 unsigned long __user *datap = (unsigned long __user *)data;
828
829 switch (request) {
830 /* read the word at location addr in the USER area. */
831 case PTRACE_PEEKUSR: {
832 unsigned long tmp;
833
834 ret = -EIO;
835 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
836 break;
837
838 tmp = 0; /* Default return condition */
839 if (addr < sizeof(struct user_regs_struct))
840 tmp = getreg(child, addr);
841 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
842 addr <= offsetof(struct user, u_debugreg[7])) {
843 addr -= offsetof(struct user, u_debugreg[0]);
844 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
845 }
846 ret = put_user(tmp, datap);
847 break;
848 }
849
850 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
851 ret = -EIO;
852 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
853 break;
854
855 if (addr < sizeof(struct user_regs_struct))
856 ret = putreg(child, addr, data);
857 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
858 addr <= offsetof(struct user, u_debugreg[7])) {
859 addr -= offsetof(struct user, u_debugreg[0]);
860 ret = ptrace_set_debugreg(child,
861 addr / sizeof(data), data);
862 }
863 break;
864
865 case PTRACE_GETREGS: /* Get all gp regs from the child. */
866 return copy_regset_to_user(child,
867 task_user_regset_view(current),
868 REGSET_GENERAL,
869 0, sizeof(struct user_regs_struct),
870 datap);
871
872 case PTRACE_SETREGS: /* Set all gp regs in the child. */
873 return copy_regset_from_user(child,
874 task_user_regset_view(current),
875 REGSET_GENERAL,
876 0, sizeof(struct user_regs_struct),
877 datap);
878
879 case PTRACE_GETFPREGS: /* Get the child FPU state. */
880 return copy_regset_to_user(child,
881 task_user_regset_view(current),
882 REGSET_FP,
883 0, sizeof(struct user_i387_struct),
884 datap);
885
886 case PTRACE_SETFPREGS: /* Set the child FPU state. */
887 return copy_regset_from_user(child,
888 task_user_regset_view(current),
889 REGSET_FP,
890 0, sizeof(struct user_i387_struct),
891 datap);
892
893#ifdef CONFIG_X86_32
894 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
895 return copy_regset_to_user(child, &user_x86_32_view,
896 REGSET_XFP,
897 0, sizeof(struct user_fxsr_struct),
898 datap) ? -EIO : 0;
899
900 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
901 return copy_regset_from_user(child, &user_x86_32_view,
902 REGSET_XFP,
903 0, sizeof(struct user_fxsr_struct),
904 datap) ? -EIO : 0;
905#endif
906
907#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
908 case PTRACE_GET_THREAD_AREA:
909 if ((int) addr < 0)
910 return -EIO;
911 ret = do_get_thread_area(child, addr,
912 (struct user_desc __user *)data);
913 break;
914
915 case PTRACE_SET_THREAD_AREA:
916 if ((int) addr < 0)
917 return -EIO;
918 ret = do_set_thread_area(child, addr,
919 (struct user_desc __user *)data, 0);
920 break;
921#endif
922
923#ifdef CONFIG_X86_64
924 /* normal 64bit interface to access TLS data.
925 Works just like arch_prctl, except that the arguments
926 are reversed. */
927 case PTRACE_ARCH_PRCTL:
928 ret = do_arch_prctl(child, data, addr);
929 break;
930#endif
931
932 default:
933 ret = ptrace_request(child, request, addr, data);
934 break;
935 }
936
937 return ret;
938}
939
940#ifdef CONFIG_IA32_EMULATION
941
942#include <linux/compat.h>
943#include <linux/syscalls.h>
944#include <asm/ia32.h>
945#include <asm/user32.h>
946
947#define R32(l,q) \
948 case offsetof(struct user32, regs.l): \
949 regs->q = value; break
950
951#define SEG32(rs) \
952 case offsetof(struct user32, regs.rs): \
953 return set_segment_reg(child, \
954 offsetof(struct user_regs_struct, rs), \
955 value); \
956 break
957
958static int putreg32(struct task_struct *child, unsigned regno, u32 value)
959{
960 struct pt_regs *regs = task_pt_regs(child);
961
962 switch (regno) {
963
964 SEG32(cs);
965 SEG32(ds);
966 SEG32(es);
967 SEG32(fs);
968 SEG32(gs);
969 SEG32(ss);
970
971 R32(ebx, bx);
972 R32(ecx, cx);
973 R32(edx, dx);
974 R32(edi, di);
975 R32(esi, si);
976 R32(ebp, bp);
977 R32(eax, ax);
978 R32(eip, ip);
979 R32(esp, sp);
980
981 case offsetof(struct user32, regs.orig_eax):
982 /*
983 * A 32-bit debugger setting orig_eax means to restore
984 * the state of the task restarting a 32-bit syscall.
985 * Make sure we interpret the -ERESTART* codes correctly
986 * in case the task is not actually still sitting at the
987 * exit from a 32-bit syscall with TS_COMPAT still set.
988 */
989 regs->orig_ax = value;
990 if (syscall_get_nr(child, regs) >= 0)
991 task_thread_info(child)->status |= TS_COMPAT;
992 break;
993
994 case offsetof(struct user32, regs.eflags):
995 return set_flags(child, value);
996
997 case offsetof(struct user32, u_debugreg[0]) ...
998 offsetof(struct user32, u_debugreg[7]):
999 regno -= offsetof(struct user32, u_debugreg[0]);
1000 return ptrace_set_debugreg(child, regno / 4, value);
1001
1002 default:
1003 if (regno > sizeof(struct user32) || (regno & 3))
1004 return -EIO;
1005
1006 /*
1007 * Other dummy fields in the virtual user structure
1008 * are ignored
1009 */
1010 break;
1011 }
1012 return 0;
1013}
1014
1015#undef R32
1016#undef SEG32
1017
1018#define R32(l,q) \
1019 case offsetof(struct user32, regs.l): \
1020 *val = regs->q; break
1021
1022#define SEG32(rs) \
1023 case offsetof(struct user32, regs.rs): \
1024 *val = get_segment_reg(child, \
1025 offsetof(struct user_regs_struct, rs)); \
1026 break
1027
1028static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1029{
1030 struct pt_regs *regs = task_pt_regs(child);
1031
1032 switch (regno) {
1033
1034 SEG32(ds);
1035 SEG32(es);
1036 SEG32(fs);
1037 SEG32(gs);
1038
1039 R32(cs, cs);
1040 R32(ss, ss);
1041 R32(ebx, bx);
1042 R32(ecx, cx);
1043 R32(edx, dx);
1044 R32(edi, di);
1045 R32(esi, si);
1046 R32(ebp, bp);
1047 R32(eax, ax);
1048 R32(orig_eax, orig_ax);
1049 R32(eip, ip);
1050 R32(esp, sp);
1051
1052 case offsetof(struct user32, regs.eflags):
1053 *val = get_flags(child);
1054 break;
1055
1056 case offsetof(struct user32, u_debugreg[0]) ...
1057 offsetof(struct user32, u_debugreg[7]):
1058 regno -= offsetof(struct user32, u_debugreg[0]);
1059 *val = ptrace_get_debugreg(child, regno / 4);
1060 break;
1061
1062 default:
1063 if (regno > sizeof(struct user32) || (regno & 3))
1064 return -EIO;
1065
1066 /*
1067 * Other dummy fields in the virtual user structure
1068 * are ignored
1069 */
1070 *val = 0;
1071 break;
1072 }
1073 return 0;
1074}
1075
1076#undef R32
1077#undef SEG32
1078
1079static int genregs32_get(struct task_struct *target,
1080 const struct user_regset *regset,
1081 unsigned int pos, unsigned int count,
1082 void *kbuf, void __user *ubuf)
1083{
1084 if (kbuf) {
1085 compat_ulong_t *k = kbuf;
1086 while (count >= sizeof(*k)) {
1087 getreg32(target, pos, k++);
1088 count -= sizeof(*k);
1089 pos += sizeof(*k);
1090 }
1091 } else {
1092 compat_ulong_t __user *u = ubuf;
1093 while (count >= sizeof(*u)) {
1094 compat_ulong_t word;
1095 getreg32(target, pos, &word);
1096 if (__put_user(word, u++))
1097 return -EFAULT;
1098 count -= sizeof(*u);
1099 pos += sizeof(*u);
1100 }
1101 }
1102
1103 return 0;
1104}
1105
1106static int genregs32_set(struct task_struct *target,
1107 const struct user_regset *regset,
1108 unsigned int pos, unsigned int count,
1109 const void *kbuf, const void __user *ubuf)
1110{
1111 int ret = 0;
1112 if (kbuf) {
1113 const compat_ulong_t *k = kbuf;
1114 while (count >= sizeof(*k) && !ret) {
1115 ret = putreg32(target, pos, *k++);
1116 count -= sizeof(*k);
1117 pos += sizeof(*k);
1118 }
1119 } else {
1120 const compat_ulong_t __user *u = ubuf;
1121 while (count >= sizeof(*u) && !ret) {
1122 compat_ulong_t word;
1123 ret = __get_user(word, u++);
1124 if (ret)
1125 break;
1126 ret = putreg32(target, pos, word);
1127 count -= sizeof(*u);
1128 pos += sizeof(*u);
1129 }
1130 }
1131 return ret;
1132}
1133
1134#ifdef CONFIG_X86_X32_ABI
1135static long x32_arch_ptrace(struct task_struct *child,
1136 compat_long_t request, compat_ulong_t caddr,
1137 compat_ulong_t cdata)
1138{
1139 unsigned long addr = caddr;
1140 unsigned long data = cdata;
1141 void __user *datap = compat_ptr(data);
1142 int ret;
1143
1144 switch (request) {
1145 /* Read 32bits at location addr in the USER area. Only allow
1146 to return the lower 32bits of segment and debug registers. */
1147 case PTRACE_PEEKUSR: {
1148 u32 tmp;
1149
1150 ret = -EIO;
1151 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1152 addr < offsetof(struct user_regs_struct, cs))
1153 break;
1154
1155 tmp = 0; /* Default return condition */
1156 if (addr < sizeof(struct user_regs_struct))
1157 tmp = getreg(child, addr);
1158 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1159 addr <= offsetof(struct user, u_debugreg[7])) {
1160 addr -= offsetof(struct user, u_debugreg[0]);
1161 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1162 }
1163 ret = put_user(tmp, (__u32 __user *)datap);
1164 break;
1165 }
1166
1167 /* Write the word at location addr in the USER area. Only allow
1168 to update segment and debug registers with the upper 32bits
1169 zero-extended. */
1170 case PTRACE_POKEUSR:
1171 ret = -EIO;
1172 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1173 addr < offsetof(struct user_regs_struct, cs))
1174 break;
1175
1176 if (addr < sizeof(struct user_regs_struct))
1177 ret = putreg(child, addr, data);
1178 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1179 addr <= offsetof(struct user, u_debugreg[7])) {
1180 addr -= offsetof(struct user, u_debugreg[0]);
1181 ret = ptrace_set_debugreg(child,
1182 addr / sizeof(data), data);
1183 }
1184 break;
1185
1186 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1187 return copy_regset_to_user(child,
1188 task_user_regset_view(current),
1189 REGSET_GENERAL,
1190 0, sizeof(struct user_regs_struct),
1191 datap);
1192
1193 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1194 return copy_regset_from_user(child,
1195 task_user_regset_view(current),
1196 REGSET_GENERAL,
1197 0, sizeof(struct user_regs_struct),
1198 datap);
1199
1200 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1201 return copy_regset_to_user(child,
1202 task_user_regset_view(current),
1203 REGSET_FP,
1204 0, sizeof(struct user_i387_struct),
1205 datap);
1206
1207 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1208 return copy_regset_from_user(child,
1209 task_user_regset_view(current),
1210 REGSET_FP,
1211 0, sizeof(struct user_i387_struct),
1212 datap);
1213
1214 default:
1215 return compat_ptrace_request(child, request, addr, data);
1216 }
1217
1218 return ret;
1219}
1220#endif
1221
1222long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1223 compat_ulong_t caddr, compat_ulong_t cdata)
1224{
1225 unsigned long addr = caddr;
1226 unsigned long data = cdata;
1227 void __user *datap = compat_ptr(data);
1228 int ret;
1229 __u32 val;
1230
1231#ifdef CONFIG_X86_X32_ABI
1232 if (!is_ia32_task())
1233 return x32_arch_ptrace(child, request, caddr, cdata);
1234#endif
1235
1236 switch (request) {
1237 case PTRACE_PEEKUSR:
1238 ret = getreg32(child, addr, &val);
1239 if (ret == 0)
1240 ret = put_user(val, (__u32 __user *)datap);
1241 break;
1242
1243 case PTRACE_POKEUSR:
1244 ret = putreg32(child, addr, data);
1245 break;
1246
1247 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1248 return copy_regset_to_user(child, &user_x86_32_view,
1249 REGSET_GENERAL,
1250 0, sizeof(struct user_regs_struct32),
1251 datap);
1252
1253 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1254 return copy_regset_from_user(child, &user_x86_32_view,
1255 REGSET_GENERAL, 0,
1256 sizeof(struct user_regs_struct32),
1257 datap);
1258
1259 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1260 return copy_regset_to_user(child, &user_x86_32_view,
1261 REGSET_FP, 0,
1262 sizeof(struct user_i387_ia32_struct),
1263 datap);
1264
1265 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1266 return copy_regset_from_user(
1267 child, &user_x86_32_view, REGSET_FP,
1268 0, sizeof(struct user_i387_ia32_struct), datap);
1269
1270 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1271 return copy_regset_to_user(child, &user_x86_32_view,
1272 REGSET_XFP, 0,
1273 sizeof(struct user32_fxsr_struct),
1274 datap);
1275
1276 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1277 return copy_regset_from_user(child, &user_x86_32_view,
1278 REGSET_XFP, 0,
1279 sizeof(struct user32_fxsr_struct),
1280 datap);
1281
1282 case PTRACE_GET_THREAD_AREA:
1283 case PTRACE_SET_THREAD_AREA:
1284 return arch_ptrace(child, request, addr, data);
1285
1286 default:
1287 return compat_ptrace_request(child, request, addr, data);
1288 }
1289
1290 return ret;
1291}
1292
1293#endif /* CONFIG_IA32_EMULATION */
1294
1295#ifdef CONFIG_X86_64
1296
1297static struct user_regset x86_64_regsets[] __read_mostly = {
1298 [REGSET_GENERAL] = {
1299 .core_note_type = NT_PRSTATUS,
1300 .n = sizeof(struct user_regs_struct) / sizeof(long),
1301 .size = sizeof(long), .align = sizeof(long),
1302 .get = genregs_get, .set = genregs_set
1303 },
1304 [REGSET_FP] = {
1305 .core_note_type = NT_PRFPREG,
1306 .n = sizeof(struct user_i387_struct) / sizeof(long),
1307 .size = sizeof(long), .align = sizeof(long),
1308 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1309 },
1310 [REGSET_XSTATE] = {
1311 .core_note_type = NT_X86_XSTATE,
1312 .size = sizeof(u64), .align = sizeof(u64),
1313 .active = xstateregs_active, .get = xstateregs_get,
1314 .set = xstateregs_set
1315 },
1316 [REGSET_IOPERM64] = {
1317 .core_note_type = NT_386_IOPERM,
1318 .n = IO_BITMAP_LONGS,
1319 .size = sizeof(long), .align = sizeof(long),
1320 .active = ioperm_active, .get = ioperm_get
1321 },
1322};
1323
1324static const struct user_regset_view user_x86_64_view = {
1325 .name = "x86_64", .e_machine = EM_X86_64,
1326 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1327};
1328
1329#else /* CONFIG_X86_32 */
1330
1331#define user_regs_struct32 user_regs_struct
1332#define genregs32_get genregs_get
1333#define genregs32_set genregs_set
1334
1335#define user_i387_ia32_struct user_i387_struct
1336#define user32_fxsr_struct user_fxsr_struct
1337
1338#endif /* CONFIG_X86_64 */
1339
1340#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1341static struct user_regset x86_32_regsets[] __read_mostly = {
1342 [REGSET_GENERAL] = {
1343 .core_note_type = NT_PRSTATUS,
1344 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1345 .size = sizeof(u32), .align = sizeof(u32),
1346 .get = genregs32_get, .set = genregs32_set
1347 },
1348 [REGSET_FP] = {
1349 .core_note_type = NT_PRFPREG,
1350 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1351 .size = sizeof(u32), .align = sizeof(u32),
1352 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1353 },
1354 [REGSET_XFP] = {
1355 .core_note_type = NT_PRXFPREG,
1356 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1357 .size = sizeof(u32), .align = sizeof(u32),
1358 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1359 },
1360 [REGSET_XSTATE] = {
1361 .core_note_type = NT_X86_XSTATE,
1362 .size = sizeof(u64), .align = sizeof(u64),
1363 .active = xstateregs_active, .get = xstateregs_get,
1364 .set = xstateregs_set
1365 },
1366 [REGSET_TLS] = {
1367 .core_note_type = NT_386_TLS,
1368 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1369 .size = sizeof(struct user_desc),
1370 .align = sizeof(struct user_desc),
1371 .active = regset_tls_active,
1372 .get = regset_tls_get, .set = regset_tls_set
1373 },
1374 [REGSET_IOPERM32] = {
1375 .core_note_type = NT_386_IOPERM,
1376 .n = IO_BITMAP_BYTES / sizeof(u32),
1377 .size = sizeof(u32), .align = sizeof(u32),
1378 .active = ioperm_active, .get = ioperm_get
1379 },
1380};
1381
1382static const struct user_regset_view user_x86_32_view = {
1383 .name = "i386", .e_machine = EM_386,
1384 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1385};
1386#endif
1387
1388/*
1389 * This represents bytes 464..511 in the memory layout exported through
1390 * the REGSET_XSTATE interface.
1391 */
1392u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1393
1394void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1395{
1396#ifdef CONFIG_X86_64
1397 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1398#endif
1399#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1400 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1401#endif
1402 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1403}
1404
1405const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1406{
1407#ifdef CONFIG_IA32_EMULATION
1408 if (test_tsk_thread_flag(task, TIF_IA32))
1409#endif
1410#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1411 return &user_x86_32_view;
1412#endif
1413#ifdef CONFIG_X86_64
1414 return &user_x86_64_view;
1415#endif
1416}
1417
1418static void fill_sigtrap_info(struct task_struct *tsk,
1419 struct pt_regs *regs,
1420 int error_code, int si_code,
1421 struct siginfo *info)
1422{
1423 tsk->thread.trap_nr = X86_TRAP_DB;
1424 tsk->thread.error_code = error_code;
1425
1426 memset(info, 0, sizeof(*info));
1427 info->si_signo = SIGTRAP;
1428 info->si_code = si_code;
1429 info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1430}
1431
1432void user_single_step_siginfo(struct task_struct *tsk,
1433 struct pt_regs *regs,
1434 struct siginfo *info)
1435{
1436 fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1437}
1438
1439void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1440 int error_code, int si_code)
1441{
1442 struct siginfo info;
1443
1444 fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1445 /* Send us the fake SIGTRAP */
1446 force_sig_info(SIGTRAP, &info, tsk);
1447}
1448
1449
1450#ifdef CONFIG_X86_32
1451# define IS_IA32 1
1452#elif defined CONFIG_IA32_EMULATION
1453# define IS_IA32 is_compat_task()
1454#else
1455# define IS_IA32 0
1456#endif
1457
1458/*
1459 * We must return the syscall number to actually look up in the table.
1460 * This can be -1L to skip running any syscall at all.
1461 */
1462long syscall_trace_enter(struct pt_regs *regs)
1463{
1464 long ret = 0;
1465
1466 /*
1467 * If we stepped into a sysenter/syscall insn, it trapped in
1468 * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1469 * If user-mode had set TF itself, then it's still clear from
1470 * do_debug() and we need to set it again to restore the user
1471 * state. If we entered on the slow path, TF was already set.
1472 */
1473 if (test_thread_flag(TIF_SINGLESTEP))
1474 regs->flags |= X86_EFLAGS_TF;
1475
1476 /* do the secure computing check first */
1477 if (secure_computing(regs->orig_ax)) {
1478 /* seccomp failures shouldn't expose any additional code. */
1479 ret = -1L;
1480 goto out;
1481 }
1482
1483 if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1484 ret = -1L;
1485
1486 if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1487 tracehook_report_syscall_entry(regs))
1488 ret = -1L;
1489
1490 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1491 trace_sys_enter(regs, regs->orig_ax);
1492
1493 if (IS_IA32)
1494 audit_syscall_entry(AUDIT_ARCH_I386,
1495 regs->orig_ax,
1496 regs->bx, regs->cx,
1497 regs->dx, regs->si);
1498#ifdef CONFIG_X86_64
1499 else
1500 audit_syscall_entry(AUDIT_ARCH_X86_64,
1501 regs->orig_ax,
1502 regs->di, regs->si,
1503 regs->dx, regs->r10);
1504#endif
1505
1506out:
1507 return ret ?: regs->orig_ax;
1508}
1509
1510void syscall_trace_leave(struct pt_regs *regs)
1511{
1512 bool step;
1513
1514 audit_syscall_exit(regs);
1515
1516 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1517 trace_sys_exit(regs, regs->ax);
1518
1519 /*
1520 * If TIF_SYSCALL_EMU is set, we only get here because of
1521 * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1522 * We already reported this syscall instruction in
1523 * syscall_trace_enter().
1524 */
1525 step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1526 !test_thread_flag(TIF_SYSCALL_EMU);
1527 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1528 tracehook_report_syscall_exit(regs, step);
1529}