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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/sched/task_stack.h>
10#include <linux/mm.h>
11#include <linux/smp.h>
12#include <linux/errno.h>
13#include <linux/slab.h>
14#include <linux/ptrace.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#include <linux/rcupdate.h>
25#include <linux/export.h>
26#include <linux/context_tracking.h>
27
28#include <linux/uaccess.h>
29#include <asm/pgtable.h>
30#include <asm/processor.h>
31#include <asm/fpu/internal.h>
32#include <asm/fpu/signal.h>
33#include <asm/fpu/regset.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
43#include "tls.h"
44
45enum x86_regset {
46 REGSET_GENERAL,
47 REGSET_FP,
48 REGSET_XFP,
49 REGSET_IOPERM64 = REGSET_XFP,
50 REGSET_XSTATE,
51 REGSET_TLS,
52 REGSET_IOPERM32,
53};
54
55struct pt_regs_offset {
56 const char *name;
57 int offset;
58};
59
60#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
61#define REG_OFFSET_END {.name = NULL, .offset = 0}
62
63static const struct pt_regs_offset regoffset_table[] = {
64#ifdef CONFIG_X86_64
65 REG_OFFSET_NAME(r15),
66 REG_OFFSET_NAME(r14),
67 REG_OFFSET_NAME(r13),
68 REG_OFFSET_NAME(r12),
69 REG_OFFSET_NAME(r11),
70 REG_OFFSET_NAME(r10),
71 REG_OFFSET_NAME(r9),
72 REG_OFFSET_NAME(r8),
73#endif
74 REG_OFFSET_NAME(bx),
75 REG_OFFSET_NAME(cx),
76 REG_OFFSET_NAME(dx),
77 REG_OFFSET_NAME(si),
78 REG_OFFSET_NAME(di),
79 REG_OFFSET_NAME(bp),
80 REG_OFFSET_NAME(ax),
81#ifdef CONFIG_X86_32
82 REG_OFFSET_NAME(ds),
83 REG_OFFSET_NAME(es),
84 REG_OFFSET_NAME(fs),
85 REG_OFFSET_NAME(gs),
86#endif
87 REG_OFFSET_NAME(orig_ax),
88 REG_OFFSET_NAME(ip),
89 REG_OFFSET_NAME(cs),
90 REG_OFFSET_NAME(flags),
91 REG_OFFSET_NAME(sp),
92 REG_OFFSET_NAME(ss),
93 REG_OFFSET_END,
94};
95
96/**
97 * regs_query_register_offset() - query register offset from its name
98 * @name: the name of a register
99 *
100 * regs_query_register_offset() returns the offset of a register in struct
101 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
102 */
103int regs_query_register_offset(const char *name)
104{
105 const struct pt_regs_offset *roff;
106 for (roff = regoffset_table; roff->name != NULL; roff++)
107 if (!strcmp(roff->name, name))
108 return roff->offset;
109 return -EINVAL;
110}
111
112/**
113 * regs_query_register_name() - query register name from its offset
114 * @offset: the offset of a register in struct pt_regs.
115 *
116 * regs_query_register_name() returns the name of a register from its
117 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
118 */
119const char *regs_query_register_name(unsigned int offset)
120{
121 const struct pt_regs_offset *roff;
122 for (roff = regoffset_table; roff->name != NULL; roff++)
123 if (roff->offset == offset)
124 return roff->name;
125 return NULL;
126}
127
128/*
129 * does not yet catch signals sent when the child dies.
130 * in exit.c or in signal.c.
131 */
132
133/*
134 * Determines which flags the user has access to [1 = access, 0 = no access].
135 */
136#define FLAG_MASK_32 ((unsigned long) \
137 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
138 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
139 X86_EFLAGS_SF | X86_EFLAGS_TF | \
140 X86_EFLAGS_DF | X86_EFLAGS_OF | \
141 X86_EFLAGS_RF | X86_EFLAGS_AC))
142
143/*
144 * Determines whether a value may be installed in a segment register.
145 */
146static inline bool invalid_selector(u16 value)
147{
148 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
149}
150
151#ifdef CONFIG_X86_32
152
153#define FLAG_MASK FLAG_MASK_32
154
155/*
156 * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
157 * when it traps. The previous stack will be directly underneath the saved
158 * registers, and 'sp/ss' won't even have been saved. Thus the '®s->sp'.
159 *
160 * Now, if the stack is empty, '®s->sp' is out of range. In this
161 * case we try to take the previous stack. To always return a non-null
162 * stack pointer we fall back to regs as stack if no previous stack
163 * exists.
164 *
165 * This is valid only for kernel mode traps.
166 */
167unsigned long kernel_stack_pointer(struct pt_regs *regs)
168{
169 unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
170 unsigned long sp = (unsigned long)®s->sp;
171 u32 *prev_esp;
172
173 if (context == (sp & ~(THREAD_SIZE - 1)))
174 return sp;
175
176 prev_esp = (u32 *)(context);
177 if (*prev_esp)
178 return (unsigned long)*prev_esp;
179
180 return (unsigned long)regs;
181}
182EXPORT_SYMBOL_GPL(kernel_stack_pointer);
183
184static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
185{
186 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
187 return ®s->bx + (regno >> 2);
188}
189
190static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
191{
192 /*
193 * Returning the value truncates it to 16 bits.
194 */
195 unsigned int retval;
196 if (offset != offsetof(struct user_regs_struct, gs))
197 retval = *pt_regs_access(task_pt_regs(task), offset);
198 else {
199 if (task == current)
200 retval = get_user_gs(task_pt_regs(task));
201 else
202 retval = task_user_gs(task);
203 }
204 return retval;
205}
206
207static int set_segment_reg(struct task_struct *task,
208 unsigned long offset, u16 value)
209{
210 /*
211 * The value argument was already truncated to 16 bits.
212 */
213 if (invalid_selector(value))
214 return -EIO;
215
216 /*
217 * For %cs and %ss we cannot permit a null selector.
218 * We can permit a bogus selector as long as it has USER_RPL.
219 * Null selectors are fine for other segment registers, but
220 * we will never get back to user mode with invalid %cs or %ss
221 * and will take the trap in iret instead. Much code relies
222 * on user_mode() to distinguish a user trap frame (which can
223 * safely use invalid selectors) from a kernel trap frame.
224 */
225 switch (offset) {
226 case offsetof(struct user_regs_struct, cs):
227 case offsetof(struct user_regs_struct, ss):
228 if (unlikely(value == 0))
229 return -EIO;
230
231 default:
232 *pt_regs_access(task_pt_regs(task), offset) = value;
233 break;
234
235 case offsetof(struct user_regs_struct, gs):
236 if (task == current)
237 set_user_gs(task_pt_regs(task), value);
238 else
239 task_user_gs(task) = value;
240 }
241
242 return 0;
243}
244
245#else /* CONFIG_X86_64 */
246
247#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
248
249static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
250{
251 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
252 return ®s->r15 + (offset / sizeof(regs->r15));
253}
254
255static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
256{
257 /*
258 * Returning the value truncates it to 16 bits.
259 */
260 unsigned int seg;
261
262 switch (offset) {
263 case offsetof(struct user_regs_struct, fs):
264 if (task == current) {
265 /* Older gas can't assemble movq %?s,%r?? */
266 asm("movl %%fs,%0" : "=r" (seg));
267 return seg;
268 }
269 return task->thread.fsindex;
270 case offsetof(struct user_regs_struct, gs):
271 if (task == current) {
272 asm("movl %%gs,%0" : "=r" (seg));
273 return seg;
274 }
275 return task->thread.gsindex;
276 case offsetof(struct user_regs_struct, ds):
277 if (task == current) {
278 asm("movl %%ds,%0" : "=r" (seg));
279 return seg;
280 }
281 return task->thread.ds;
282 case offsetof(struct user_regs_struct, es):
283 if (task == current) {
284 asm("movl %%es,%0" : "=r" (seg));
285 return seg;
286 }
287 return task->thread.es;
288
289 case offsetof(struct user_regs_struct, cs):
290 case offsetof(struct user_regs_struct, ss):
291 break;
292 }
293 return *pt_regs_access(task_pt_regs(task), offset);
294}
295
296static int set_segment_reg(struct task_struct *task,
297 unsigned long offset, u16 value)
298{
299 /*
300 * The value argument was already truncated to 16 bits.
301 */
302 if (invalid_selector(value))
303 return -EIO;
304
305 switch (offset) {
306 case offsetof(struct user_regs_struct,fs):
307 task->thread.fsindex = value;
308 if (task == current)
309 loadsegment(fs, task->thread.fsindex);
310 break;
311 case offsetof(struct user_regs_struct,gs):
312 task->thread.gsindex = value;
313 if (task == current)
314 load_gs_index(task->thread.gsindex);
315 break;
316 case offsetof(struct user_regs_struct,ds):
317 task->thread.ds = value;
318 if (task == current)
319 loadsegment(ds, task->thread.ds);
320 break;
321 case offsetof(struct user_regs_struct,es):
322 task->thread.es = value;
323 if (task == current)
324 loadsegment(es, task->thread.es);
325 break;
326
327 /*
328 * Can't actually change these in 64-bit mode.
329 */
330 case offsetof(struct user_regs_struct,cs):
331 if (unlikely(value == 0))
332 return -EIO;
333 task_pt_regs(task)->cs = value;
334 break;
335 case offsetof(struct user_regs_struct,ss):
336 if (unlikely(value == 0))
337 return -EIO;
338 task_pt_regs(task)->ss = value;
339 break;
340 }
341
342 return 0;
343}
344
345#endif /* CONFIG_X86_32 */
346
347static unsigned long get_flags(struct task_struct *task)
348{
349 unsigned long retval = task_pt_regs(task)->flags;
350
351 /*
352 * If the debugger set TF, hide it from the readout.
353 */
354 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
355 retval &= ~X86_EFLAGS_TF;
356
357 return retval;
358}
359
360static int set_flags(struct task_struct *task, unsigned long value)
361{
362 struct pt_regs *regs = task_pt_regs(task);
363
364 /*
365 * If the user value contains TF, mark that
366 * it was not "us" (the debugger) that set it.
367 * If not, make sure it stays set if we had.
368 */
369 if (value & X86_EFLAGS_TF)
370 clear_tsk_thread_flag(task, TIF_FORCED_TF);
371 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
372 value |= X86_EFLAGS_TF;
373
374 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
375
376 return 0;
377}
378
379static int putreg(struct task_struct *child,
380 unsigned long offset, unsigned long value)
381{
382 switch (offset) {
383 case offsetof(struct user_regs_struct, cs):
384 case offsetof(struct user_regs_struct, ds):
385 case offsetof(struct user_regs_struct, es):
386 case offsetof(struct user_regs_struct, fs):
387 case offsetof(struct user_regs_struct, gs):
388 case offsetof(struct user_regs_struct, ss):
389 return set_segment_reg(child, offset, value);
390
391 case offsetof(struct user_regs_struct, flags):
392 return set_flags(child, value);
393
394#ifdef CONFIG_X86_64
395 case offsetof(struct user_regs_struct,fs_base):
396 if (value >= TASK_SIZE_MAX)
397 return -EIO;
398 /*
399 * When changing the segment base, use do_arch_prctl_64
400 * to set either thread.fs or thread.fsindex and the
401 * corresponding GDT slot.
402 */
403 if (child->thread.fsbase != value)
404 return do_arch_prctl_64(child, ARCH_SET_FS, value);
405 return 0;
406 case offsetof(struct user_regs_struct,gs_base):
407 /*
408 * Exactly the same here as the %fs handling above.
409 */
410 if (value >= TASK_SIZE_MAX)
411 return -EIO;
412 if (child->thread.gsbase != value)
413 return do_arch_prctl_64(child, ARCH_SET_GS, value);
414 return 0;
415#endif
416 }
417
418 *pt_regs_access(task_pt_regs(child), offset) = value;
419 return 0;
420}
421
422static unsigned long getreg(struct task_struct *task, unsigned long offset)
423{
424 switch (offset) {
425 case offsetof(struct user_regs_struct, cs):
426 case offsetof(struct user_regs_struct, ds):
427 case offsetof(struct user_regs_struct, es):
428 case offsetof(struct user_regs_struct, fs):
429 case offsetof(struct user_regs_struct, gs):
430 case offsetof(struct user_regs_struct, ss):
431 return get_segment_reg(task, offset);
432
433 case offsetof(struct user_regs_struct, flags):
434 return get_flags(task);
435
436#ifdef CONFIG_X86_64
437 case offsetof(struct user_regs_struct, fs_base): {
438 /*
439 * XXX: This will not behave as expected if called on
440 * current or if fsindex != 0.
441 */
442 return task->thread.fsbase;
443 }
444 case offsetof(struct user_regs_struct, gs_base): {
445 /*
446 * XXX: This will not behave as expected if called on
447 * current or if fsindex != 0.
448 */
449 return task->thread.gsbase;
450 }
451#endif
452 }
453
454 return *pt_regs_access(task_pt_regs(task), offset);
455}
456
457static int genregs_get(struct task_struct *target,
458 const struct user_regset *regset,
459 unsigned int pos, unsigned int count,
460 void *kbuf, void __user *ubuf)
461{
462 if (kbuf) {
463 unsigned long *k = kbuf;
464 while (count >= sizeof(*k)) {
465 *k++ = getreg(target, pos);
466 count -= sizeof(*k);
467 pos += sizeof(*k);
468 }
469 } else {
470 unsigned long __user *u = ubuf;
471 while (count >= sizeof(*u)) {
472 if (__put_user(getreg(target, pos), u++))
473 return -EFAULT;
474 count -= sizeof(*u);
475 pos += sizeof(*u);
476 }
477 }
478
479 return 0;
480}
481
482static int genregs_set(struct task_struct *target,
483 const struct user_regset *regset,
484 unsigned int pos, unsigned int count,
485 const void *kbuf, const void __user *ubuf)
486{
487 int ret = 0;
488 if (kbuf) {
489 const unsigned long *k = kbuf;
490 while (count >= sizeof(*k) && !ret) {
491 ret = putreg(target, pos, *k++);
492 count -= sizeof(*k);
493 pos += sizeof(*k);
494 }
495 } else {
496 const unsigned long __user *u = ubuf;
497 while (count >= sizeof(*u) && !ret) {
498 unsigned long word;
499 ret = __get_user(word, u++);
500 if (ret)
501 break;
502 ret = putreg(target, pos, word);
503 count -= sizeof(*u);
504 pos += sizeof(*u);
505 }
506 }
507 return ret;
508}
509
510static void ptrace_triggered(struct perf_event *bp,
511 struct perf_sample_data *data,
512 struct pt_regs *regs)
513{
514 int i;
515 struct thread_struct *thread = &(current->thread);
516
517 /*
518 * Store in the virtual DR6 register the fact that the breakpoint
519 * was hit so the thread's debugger will see it.
520 */
521 for (i = 0; i < HBP_NUM; i++) {
522 if (thread->ptrace_bps[i] == bp)
523 break;
524 }
525
526 thread->debugreg6 |= (DR_TRAP0 << i);
527}
528
529/*
530 * Walk through every ptrace breakpoints for this thread and
531 * build the dr7 value on top of their attributes.
532 *
533 */
534static unsigned long ptrace_get_dr7(struct perf_event *bp[])
535{
536 int i;
537 int dr7 = 0;
538 struct arch_hw_breakpoint *info;
539
540 for (i = 0; i < HBP_NUM; i++) {
541 if (bp[i] && !bp[i]->attr.disabled) {
542 info = counter_arch_bp(bp[i]);
543 dr7 |= encode_dr7(i, info->len, info->type);
544 }
545 }
546
547 return dr7;
548}
549
550static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
551 int len, int type, bool disabled)
552{
553 int err, bp_len, bp_type;
554
555 err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
556 if (!err) {
557 attr->bp_len = bp_len;
558 attr->bp_type = bp_type;
559 attr->disabled = disabled;
560 }
561
562 return err;
563}
564
565static struct perf_event *
566ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
567 unsigned long addr, bool disabled)
568{
569 struct perf_event_attr attr;
570 int err;
571
572 ptrace_breakpoint_init(&attr);
573 attr.bp_addr = addr;
574
575 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
576 if (err)
577 return ERR_PTR(err);
578
579 return register_user_hw_breakpoint(&attr, ptrace_triggered,
580 NULL, tsk);
581}
582
583static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
584 int disabled)
585{
586 struct perf_event_attr attr = bp->attr;
587 int err;
588
589 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
590 if (err)
591 return err;
592
593 return modify_user_hw_breakpoint(bp, &attr);
594}
595
596/*
597 * Handle ptrace writes to debug register 7.
598 */
599static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
600{
601 struct thread_struct *thread = &tsk->thread;
602 unsigned long old_dr7;
603 bool second_pass = false;
604 int i, rc, ret = 0;
605
606 data &= ~DR_CONTROL_RESERVED;
607 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
608
609restore:
610 rc = 0;
611 for (i = 0; i < HBP_NUM; i++) {
612 unsigned len, type;
613 bool disabled = !decode_dr7(data, i, &len, &type);
614 struct perf_event *bp = thread->ptrace_bps[i];
615
616 if (!bp) {
617 if (disabled)
618 continue;
619
620 bp = ptrace_register_breakpoint(tsk,
621 len, type, 0, disabled);
622 if (IS_ERR(bp)) {
623 rc = PTR_ERR(bp);
624 break;
625 }
626
627 thread->ptrace_bps[i] = bp;
628 continue;
629 }
630
631 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
632 if (rc)
633 break;
634 }
635
636 /* Restore if the first pass failed, second_pass shouldn't fail. */
637 if (rc && !WARN_ON(second_pass)) {
638 ret = rc;
639 data = old_dr7;
640 second_pass = true;
641 goto restore;
642 }
643
644 return ret;
645}
646
647/*
648 * Handle PTRACE_PEEKUSR calls for the debug register area.
649 */
650static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
651{
652 struct thread_struct *thread = &tsk->thread;
653 unsigned long val = 0;
654
655 if (n < HBP_NUM) {
656 struct perf_event *bp = thread->ptrace_bps[n];
657
658 if (bp)
659 val = bp->hw.info.address;
660 } else if (n == 6) {
661 val = thread->debugreg6;
662 } else if (n == 7) {
663 val = thread->ptrace_dr7;
664 }
665 return val;
666}
667
668static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
669 unsigned long addr)
670{
671 struct thread_struct *t = &tsk->thread;
672 struct perf_event *bp = t->ptrace_bps[nr];
673 int err = 0;
674
675 if (!bp) {
676 /*
677 * Put stub len and type to create an inactive but correct bp.
678 *
679 * CHECKME: the previous code returned -EIO if the addr wasn't
680 * a valid task virtual addr. The new one will return -EINVAL in
681 * this case.
682 * -EINVAL may be what we want for in-kernel breakpoints users,
683 * but -EIO looks better for ptrace, since we refuse a register
684 * writing for the user. And anyway this is the previous
685 * behaviour.
686 */
687 bp = ptrace_register_breakpoint(tsk,
688 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
689 addr, true);
690 if (IS_ERR(bp))
691 err = PTR_ERR(bp);
692 else
693 t->ptrace_bps[nr] = bp;
694 } else {
695 struct perf_event_attr attr = bp->attr;
696
697 attr.bp_addr = addr;
698 err = modify_user_hw_breakpoint(bp, &attr);
699 }
700
701 return err;
702}
703
704/*
705 * Handle PTRACE_POKEUSR calls for the debug register area.
706 */
707static int ptrace_set_debugreg(struct task_struct *tsk, int n,
708 unsigned long val)
709{
710 struct thread_struct *thread = &tsk->thread;
711 /* There are no DR4 or DR5 registers */
712 int rc = -EIO;
713
714 if (n < HBP_NUM) {
715 rc = ptrace_set_breakpoint_addr(tsk, n, val);
716 } else if (n == 6) {
717 thread->debugreg6 = val;
718 rc = 0;
719 } else if (n == 7) {
720 rc = ptrace_write_dr7(tsk, val);
721 if (!rc)
722 thread->ptrace_dr7 = val;
723 }
724 return rc;
725}
726
727/*
728 * These access the current or another (stopped) task's io permission
729 * bitmap for debugging or core dump.
730 */
731static int ioperm_active(struct task_struct *target,
732 const struct user_regset *regset)
733{
734 return target->thread.io_bitmap_max / regset->size;
735}
736
737static int ioperm_get(struct task_struct *target,
738 const struct user_regset *regset,
739 unsigned int pos, unsigned int count,
740 void *kbuf, void __user *ubuf)
741{
742 if (!target->thread.io_bitmap_ptr)
743 return -ENXIO;
744
745 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
746 target->thread.io_bitmap_ptr,
747 0, IO_BITMAP_BYTES);
748}
749
750/*
751 * Called by kernel/ptrace.c when detaching..
752 *
753 * Make sure the single step bit is not set.
754 */
755void ptrace_disable(struct task_struct *child)
756{
757 user_disable_single_step(child);
758#ifdef TIF_SYSCALL_EMU
759 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
760#endif
761}
762
763#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
764static const struct user_regset_view user_x86_32_view; /* Initialized below. */
765#endif
766
767long arch_ptrace(struct task_struct *child, long request,
768 unsigned long addr, unsigned long data)
769{
770 int ret;
771 unsigned long __user *datap = (unsigned long __user *)data;
772
773 switch (request) {
774 /* read the word at location addr in the USER area. */
775 case PTRACE_PEEKUSR: {
776 unsigned long tmp;
777
778 ret = -EIO;
779 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
780 break;
781
782 tmp = 0; /* Default return condition */
783 if (addr < sizeof(struct user_regs_struct))
784 tmp = getreg(child, addr);
785 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
786 addr <= offsetof(struct user, u_debugreg[7])) {
787 addr -= offsetof(struct user, u_debugreg[0]);
788 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
789 }
790 ret = put_user(tmp, datap);
791 break;
792 }
793
794 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
795 ret = -EIO;
796 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
797 break;
798
799 if (addr < sizeof(struct user_regs_struct))
800 ret = putreg(child, addr, data);
801 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
802 addr <= offsetof(struct user, u_debugreg[7])) {
803 addr -= offsetof(struct user, u_debugreg[0]);
804 ret = ptrace_set_debugreg(child,
805 addr / sizeof(data), data);
806 }
807 break;
808
809 case PTRACE_GETREGS: /* Get all gp regs from the child. */
810 return copy_regset_to_user(child,
811 task_user_regset_view(current),
812 REGSET_GENERAL,
813 0, sizeof(struct user_regs_struct),
814 datap);
815
816 case PTRACE_SETREGS: /* Set all gp regs in the child. */
817 return copy_regset_from_user(child,
818 task_user_regset_view(current),
819 REGSET_GENERAL,
820 0, sizeof(struct user_regs_struct),
821 datap);
822
823 case PTRACE_GETFPREGS: /* Get the child FPU state. */
824 return copy_regset_to_user(child,
825 task_user_regset_view(current),
826 REGSET_FP,
827 0, sizeof(struct user_i387_struct),
828 datap);
829
830 case PTRACE_SETFPREGS: /* Set the child FPU state. */
831 return copy_regset_from_user(child,
832 task_user_regset_view(current),
833 REGSET_FP,
834 0, sizeof(struct user_i387_struct),
835 datap);
836
837#ifdef CONFIG_X86_32
838 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
839 return copy_regset_to_user(child, &user_x86_32_view,
840 REGSET_XFP,
841 0, sizeof(struct user_fxsr_struct),
842 datap) ? -EIO : 0;
843
844 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
845 return copy_regset_from_user(child, &user_x86_32_view,
846 REGSET_XFP,
847 0, sizeof(struct user_fxsr_struct),
848 datap) ? -EIO : 0;
849#endif
850
851#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
852 case PTRACE_GET_THREAD_AREA:
853 if ((int) addr < 0)
854 return -EIO;
855 ret = do_get_thread_area(child, addr,
856 (struct user_desc __user *)data);
857 break;
858
859 case PTRACE_SET_THREAD_AREA:
860 if ((int) addr < 0)
861 return -EIO;
862 ret = do_set_thread_area(child, addr,
863 (struct user_desc __user *)data, 0);
864 break;
865#endif
866
867#ifdef CONFIG_X86_64
868 /* normal 64bit interface to access TLS data.
869 Works just like arch_prctl, except that the arguments
870 are reversed. */
871 case PTRACE_ARCH_PRCTL:
872 ret = do_arch_prctl_64(child, data, addr);
873 break;
874#endif
875
876 default:
877 ret = ptrace_request(child, request, addr, data);
878 break;
879 }
880
881 return ret;
882}
883
884#ifdef CONFIG_IA32_EMULATION
885
886#include <linux/compat.h>
887#include <linux/syscalls.h>
888#include <asm/ia32.h>
889#include <asm/user32.h>
890
891#define R32(l,q) \
892 case offsetof(struct user32, regs.l): \
893 regs->q = value; break
894
895#define SEG32(rs) \
896 case offsetof(struct user32, regs.rs): \
897 return set_segment_reg(child, \
898 offsetof(struct user_regs_struct, rs), \
899 value); \
900 break
901
902static int putreg32(struct task_struct *child, unsigned regno, u32 value)
903{
904 struct pt_regs *regs = task_pt_regs(child);
905
906 switch (regno) {
907
908 SEG32(cs);
909 SEG32(ds);
910 SEG32(es);
911 SEG32(fs);
912 SEG32(gs);
913 SEG32(ss);
914
915 R32(ebx, bx);
916 R32(ecx, cx);
917 R32(edx, dx);
918 R32(edi, di);
919 R32(esi, si);
920 R32(ebp, bp);
921 R32(eax, ax);
922 R32(eip, ip);
923 R32(esp, sp);
924
925 case offsetof(struct user32, regs.orig_eax):
926 /*
927 * Warning: bizarre corner case fixup here. A 32-bit
928 * debugger setting orig_eax to -1 wants to disable
929 * syscall restart. Make sure that the syscall
930 * restart code sign-extends orig_ax. Also make sure
931 * we interpret the -ERESTART* codes correctly if
932 * loaded into regs->ax in case the task is not
933 * actually still sitting at the exit from a 32-bit
934 * syscall with TS_COMPAT still set.
935 */
936 regs->orig_ax = value;
937 if (syscall_get_nr(child, regs) >= 0)
938 child->thread_info.status |= TS_I386_REGS_POKED;
939 break;
940
941 case offsetof(struct user32, regs.eflags):
942 return set_flags(child, value);
943
944 case offsetof(struct user32, u_debugreg[0]) ...
945 offsetof(struct user32, u_debugreg[7]):
946 regno -= offsetof(struct user32, u_debugreg[0]);
947 return ptrace_set_debugreg(child, regno / 4, value);
948
949 default:
950 if (regno > sizeof(struct user32) || (regno & 3))
951 return -EIO;
952
953 /*
954 * Other dummy fields in the virtual user structure
955 * are ignored
956 */
957 break;
958 }
959 return 0;
960}
961
962#undef R32
963#undef SEG32
964
965#define R32(l,q) \
966 case offsetof(struct user32, regs.l): \
967 *val = regs->q; break
968
969#define SEG32(rs) \
970 case offsetof(struct user32, regs.rs): \
971 *val = get_segment_reg(child, \
972 offsetof(struct user_regs_struct, rs)); \
973 break
974
975static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
976{
977 struct pt_regs *regs = task_pt_regs(child);
978
979 switch (regno) {
980
981 SEG32(ds);
982 SEG32(es);
983 SEG32(fs);
984 SEG32(gs);
985
986 R32(cs, cs);
987 R32(ss, ss);
988 R32(ebx, bx);
989 R32(ecx, cx);
990 R32(edx, dx);
991 R32(edi, di);
992 R32(esi, si);
993 R32(ebp, bp);
994 R32(eax, ax);
995 R32(orig_eax, orig_ax);
996 R32(eip, ip);
997 R32(esp, sp);
998
999 case offsetof(struct user32, regs.eflags):
1000 *val = get_flags(child);
1001 break;
1002
1003 case offsetof(struct user32, u_debugreg[0]) ...
1004 offsetof(struct user32, u_debugreg[7]):
1005 regno -= offsetof(struct user32, u_debugreg[0]);
1006 *val = ptrace_get_debugreg(child, regno / 4);
1007 break;
1008
1009 default:
1010 if (regno > sizeof(struct user32) || (regno & 3))
1011 return -EIO;
1012
1013 /*
1014 * Other dummy fields in the virtual user structure
1015 * are ignored
1016 */
1017 *val = 0;
1018 break;
1019 }
1020 return 0;
1021}
1022
1023#undef R32
1024#undef SEG32
1025
1026static int genregs32_get(struct task_struct *target,
1027 const struct user_regset *regset,
1028 unsigned int pos, unsigned int count,
1029 void *kbuf, void __user *ubuf)
1030{
1031 if (kbuf) {
1032 compat_ulong_t *k = kbuf;
1033 while (count >= sizeof(*k)) {
1034 getreg32(target, pos, k++);
1035 count -= sizeof(*k);
1036 pos += sizeof(*k);
1037 }
1038 } else {
1039 compat_ulong_t __user *u = ubuf;
1040 while (count >= sizeof(*u)) {
1041 compat_ulong_t word;
1042 getreg32(target, pos, &word);
1043 if (__put_user(word, u++))
1044 return -EFAULT;
1045 count -= sizeof(*u);
1046 pos += sizeof(*u);
1047 }
1048 }
1049
1050 return 0;
1051}
1052
1053static int genregs32_set(struct task_struct *target,
1054 const struct user_regset *regset,
1055 unsigned int pos, unsigned int count,
1056 const void *kbuf, const void __user *ubuf)
1057{
1058 int ret = 0;
1059 if (kbuf) {
1060 const compat_ulong_t *k = kbuf;
1061 while (count >= sizeof(*k) && !ret) {
1062 ret = putreg32(target, pos, *k++);
1063 count -= sizeof(*k);
1064 pos += sizeof(*k);
1065 }
1066 } else {
1067 const compat_ulong_t __user *u = ubuf;
1068 while (count >= sizeof(*u) && !ret) {
1069 compat_ulong_t word;
1070 ret = __get_user(word, u++);
1071 if (ret)
1072 break;
1073 ret = putreg32(target, pos, word);
1074 count -= sizeof(*u);
1075 pos += sizeof(*u);
1076 }
1077 }
1078 return ret;
1079}
1080
1081static long ia32_arch_ptrace(struct task_struct *child, compat_long_t request,
1082 compat_ulong_t caddr, compat_ulong_t cdata)
1083{
1084 unsigned long addr = caddr;
1085 unsigned long data = cdata;
1086 void __user *datap = compat_ptr(data);
1087 int ret;
1088 __u32 val;
1089
1090 switch (request) {
1091 case PTRACE_PEEKUSR:
1092 ret = getreg32(child, addr, &val);
1093 if (ret == 0)
1094 ret = put_user(val, (__u32 __user *)datap);
1095 break;
1096
1097 case PTRACE_POKEUSR:
1098 ret = putreg32(child, addr, data);
1099 break;
1100
1101 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1102 return copy_regset_to_user(child, &user_x86_32_view,
1103 REGSET_GENERAL,
1104 0, sizeof(struct user_regs_struct32),
1105 datap);
1106
1107 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1108 return copy_regset_from_user(child, &user_x86_32_view,
1109 REGSET_GENERAL, 0,
1110 sizeof(struct user_regs_struct32),
1111 datap);
1112
1113 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1114 return copy_regset_to_user(child, &user_x86_32_view,
1115 REGSET_FP, 0,
1116 sizeof(struct user_i387_ia32_struct),
1117 datap);
1118
1119 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1120 return copy_regset_from_user(
1121 child, &user_x86_32_view, REGSET_FP,
1122 0, sizeof(struct user_i387_ia32_struct), datap);
1123
1124 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1125 return copy_regset_to_user(child, &user_x86_32_view,
1126 REGSET_XFP, 0,
1127 sizeof(struct user32_fxsr_struct),
1128 datap);
1129
1130 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1131 return copy_regset_from_user(child, &user_x86_32_view,
1132 REGSET_XFP, 0,
1133 sizeof(struct user32_fxsr_struct),
1134 datap);
1135
1136 case PTRACE_GET_THREAD_AREA:
1137 case PTRACE_SET_THREAD_AREA:
1138 return arch_ptrace(child, request, addr, data);
1139
1140 default:
1141 return compat_ptrace_request(child, request, addr, data);
1142 }
1143
1144 return ret;
1145}
1146#endif /* CONFIG_IA32_EMULATION */
1147
1148#ifdef CONFIG_X86_X32_ABI
1149static long x32_arch_ptrace(struct task_struct *child,
1150 compat_long_t request, compat_ulong_t caddr,
1151 compat_ulong_t cdata)
1152{
1153 unsigned long addr = caddr;
1154 unsigned long data = cdata;
1155 void __user *datap = compat_ptr(data);
1156 int ret;
1157
1158 switch (request) {
1159 /* Read 32bits at location addr in the USER area. Only allow
1160 to return the lower 32bits of segment and debug registers. */
1161 case PTRACE_PEEKUSR: {
1162 u32 tmp;
1163
1164 ret = -EIO;
1165 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1166 addr < offsetof(struct user_regs_struct, cs))
1167 break;
1168
1169 tmp = 0; /* Default return condition */
1170 if (addr < sizeof(struct user_regs_struct))
1171 tmp = getreg(child, addr);
1172 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1173 addr <= offsetof(struct user, u_debugreg[7])) {
1174 addr -= offsetof(struct user, u_debugreg[0]);
1175 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1176 }
1177 ret = put_user(tmp, (__u32 __user *)datap);
1178 break;
1179 }
1180
1181 /* Write the word at location addr in the USER area. Only allow
1182 to update segment and debug registers with the upper 32bits
1183 zero-extended. */
1184 case PTRACE_POKEUSR:
1185 ret = -EIO;
1186 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1187 addr < offsetof(struct user_regs_struct, cs))
1188 break;
1189
1190 if (addr < sizeof(struct user_regs_struct))
1191 ret = putreg(child, addr, data);
1192 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1193 addr <= offsetof(struct user, u_debugreg[7])) {
1194 addr -= offsetof(struct user, u_debugreg[0]);
1195 ret = ptrace_set_debugreg(child,
1196 addr / sizeof(data), data);
1197 }
1198 break;
1199
1200 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1201 return copy_regset_to_user(child,
1202 task_user_regset_view(current),
1203 REGSET_GENERAL,
1204 0, sizeof(struct user_regs_struct),
1205 datap);
1206
1207 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1208 return copy_regset_from_user(child,
1209 task_user_regset_view(current),
1210 REGSET_GENERAL,
1211 0, sizeof(struct user_regs_struct),
1212 datap);
1213
1214 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1215 return copy_regset_to_user(child,
1216 task_user_regset_view(current),
1217 REGSET_FP,
1218 0, sizeof(struct user_i387_struct),
1219 datap);
1220
1221 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1222 return copy_regset_from_user(child,
1223 task_user_regset_view(current),
1224 REGSET_FP,
1225 0, sizeof(struct user_i387_struct),
1226 datap);
1227
1228 default:
1229 return compat_ptrace_request(child, request, addr, data);
1230 }
1231
1232 return ret;
1233}
1234#endif
1235
1236#ifdef CONFIG_COMPAT
1237long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1238 compat_ulong_t caddr, compat_ulong_t cdata)
1239{
1240#ifdef CONFIG_X86_X32_ABI
1241 if (!in_ia32_syscall())
1242 return x32_arch_ptrace(child, request, caddr, cdata);
1243#endif
1244#ifdef CONFIG_IA32_EMULATION
1245 return ia32_arch_ptrace(child, request, caddr, cdata);
1246#else
1247 return 0;
1248#endif
1249}
1250#endif /* CONFIG_COMPAT */
1251
1252#ifdef CONFIG_X86_64
1253
1254static struct user_regset x86_64_regsets[] __ro_after_init = {
1255 [REGSET_GENERAL] = {
1256 .core_note_type = NT_PRSTATUS,
1257 .n = sizeof(struct user_regs_struct) / sizeof(long),
1258 .size = sizeof(long), .align = sizeof(long),
1259 .get = genregs_get, .set = genregs_set
1260 },
1261 [REGSET_FP] = {
1262 .core_note_type = NT_PRFPREG,
1263 .n = sizeof(struct user_i387_struct) / sizeof(long),
1264 .size = sizeof(long), .align = sizeof(long),
1265 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1266 },
1267 [REGSET_XSTATE] = {
1268 .core_note_type = NT_X86_XSTATE,
1269 .size = sizeof(u64), .align = sizeof(u64),
1270 .active = xstateregs_active, .get = xstateregs_get,
1271 .set = xstateregs_set
1272 },
1273 [REGSET_IOPERM64] = {
1274 .core_note_type = NT_386_IOPERM,
1275 .n = IO_BITMAP_LONGS,
1276 .size = sizeof(long), .align = sizeof(long),
1277 .active = ioperm_active, .get = ioperm_get
1278 },
1279};
1280
1281static const struct user_regset_view user_x86_64_view = {
1282 .name = "x86_64", .e_machine = EM_X86_64,
1283 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1284};
1285
1286#else /* CONFIG_X86_32 */
1287
1288#define user_regs_struct32 user_regs_struct
1289#define genregs32_get genregs_get
1290#define genregs32_set genregs_set
1291
1292#endif /* CONFIG_X86_64 */
1293
1294#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1295static struct user_regset x86_32_regsets[] __ro_after_init = {
1296 [REGSET_GENERAL] = {
1297 .core_note_type = NT_PRSTATUS,
1298 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1299 .size = sizeof(u32), .align = sizeof(u32),
1300 .get = genregs32_get, .set = genregs32_set
1301 },
1302 [REGSET_FP] = {
1303 .core_note_type = NT_PRFPREG,
1304 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1305 .size = sizeof(u32), .align = sizeof(u32),
1306 .active = regset_fpregs_active, .get = fpregs_get, .set = fpregs_set
1307 },
1308 [REGSET_XFP] = {
1309 .core_note_type = NT_PRXFPREG,
1310 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1311 .size = sizeof(u32), .align = sizeof(u32),
1312 .active = regset_xregset_fpregs_active, .get = xfpregs_get, .set = xfpregs_set
1313 },
1314 [REGSET_XSTATE] = {
1315 .core_note_type = NT_X86_XSTATE,
1316 .size = sizeof(u64), .align = sizeof(u64),
1317 .active = xstateregs_active, .get = xstateregs_get,
1318 .set = xstateregs_set
1319 },
1320 [REGSET_TLS] = {
1321 .core_note_type = NT_386_TLS,
1322 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1323 .size = sizeof(struct user_desc),
1324 .align = sizeof(struct user_desc),
1325 .active = regset_tls_active,
1326 .get = regset_tls_get, .set = regset_tls_set
1327 },
1328 [REGSET_IOPERM32] = {
1329 .core_note_type = NT_386_IOPERM,
1330 .n = IO_BITMAP_BYTES / sizeof(u32),
1331 .size = sizeof(u32), .align = sizeof(u32),
1332 .active = ioperm_active, .get = ioperm_get
1333 },
1334};
1335
1336static const struct user_regset_view user_x86_32_view = {
1337 .name = "i386", .e_machine = EM_386,
1338 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1339};
1340#endif
1341
1342/*
1343 * This represents bytes 464..511 in the memory layout exported through
1344 * the REGSET_XSTATE interface.
1345 */
1346u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1347
1348void __init update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1349{
1350#ifdef CONFIG_X86_64
1351 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1352#endif
1353#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1354 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1355#endif
1356 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1357}
1358
1359const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1360{
1361#ifdef CONFIG_IA32_EMULATION
1362 if (!user_64bit_mode(task_pt_regs(task)))
1363#endif
1364#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1365 return &user_x86_32_view;
1366#endif
1367#ifdef CONFIG_X86_64
1368 return &user_x86_64_view;
1369#endif
1370}
1371
1372static void fill_sigtrap_info(struct task_struct *tsk,
1373 struct pt_regs *regs,
1374 int error_code, int si_code,
1375 struct siginfo *info)
1376{
1377 tsk->thread.trap_nr = X86_TRAP_DB;
1378 tsk->thread.error_code = error_code;
1379
1380 memset(info, 0, sizeof(*info));
1381 info->si_signo = SIGTRAP;
1382 info->si_code = si_code;
1383 info->si_addr = user_mode(regs) ? (void __user *)regs->ip : NULL;
1384}
1385
1386void user_single_step_siginfo(struct task_struct *tsk,
1387 struct pt_regs *regs,
1388 struct siginfo *info)
1389{
1390 fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1391}
1392
1393void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1394 int error_code, int si_code)
1395{
1396 struct siginfo info;
1397
1398 fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1399 /* Send us the fake SIGTRAP */
1400 force_sig_info(SIGTRAP, &info, tsk);
1401}
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#include <linux/rcupdate.h>
25#include <linux/export.h>
26#include <linux/context_tracking.h>
27
28#include <asm/uaccess.h>
29#include <asm/pgtable.h>
30#include <asm/processor.h>
31#include <asm/i387.h>
32#include <asm/fpu-internal.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
41#include "tls.h"
42
43#define CREATE_TRACE_POINTS
44#include <trace/events/syscalls.h>
45
46enum x86_regset {
47 REGSET_GENERAL,
48 REGSET_FP,
49 REGSET_XFP,
50 REGSET_IOPERM64 = REGSET_XFP,
51 REGSET_XSTATE,
52 REGSET_TLS,
53 REGSET_IOPERM32,
54};
55
56struct pt_regs_offset {
57 const char *name;
58 int offset;
59};
60
61#define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
62#define REG_OFFSET_END {.name = NULL, .offset = 0}
63
64static const struct pt_regs_offset regoffset_table[] = {
65#ifdef CONFIG_X86_64
66 REG_OFFSET_NAME(r15),
67 REG_OFFSET_NAME(r14),
68 REG_OFFSET_NAME(r13),
69 REG_OFFSET_NAME(r12),
70 REG_OFFSET_NAME(r11),
71 REG_OFFSET_NAME(r10),
72 REG_OFFSET_NAME(r9),
73 REG_OFFSET_NAME(r8),
74#endif
75 REG_OFFSET_NAME(bx),
76 REG_OFFSET_NAME(cx),
77 REG_OFFSET_NAME(dx),
78 REG_OFFSET_NAME(si),
79 REG_OFFSET_NAME(di),
80 REG_OFFSET_NAME(bp),
81 REG_OFFSET_NAME(ax),
82#ifdef CONFIG_X86_32
83 REG_OFFSET_NAME(ds),
84 REG_OFFSET_NAME(es),
85 REG_OFFSET_NAME(fs),
86 REG_OFFSET_NAME(gs),
87#endif
88 REG_OFFSET_NAME(orig_ax),
89 REG_OFFSET_NAME(ip),
90 REG_OFFSET_NAME(cs),
91 REG_OFFSET_NAME(flags),
92 REG_OFFSET_NAME(sp),
93 REG_OFFSET_NAME(ss),
94 REG_OFFSET_END,
95};
96
97/**
98 * regs_query_register_offset() - query register offset from its name
99 * @name: the name of a register
100 *
101 * regs_query_register_offset() returns the offset of a register in struct
102 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
103 */
104int regs_query_register_offset(const char *name)
105{
106 const struct pt_regs_offset *roff;
107 for (roff = regoffset_table; roff->name != NULL; roff++)
108 if (!strcmp(roff->name, name))
109 return roff->offset;
110 return -EINVAL;
111}
112
113/**
114 * regs_query_register_name() - query register name from its offset
115 * @offset: the offset of a register in struct pt_regs.
116 *
117 * regs_query_register_name() returns the name of a register from its
118 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
119 */
120const char *regs_query_register_name(unsigned int offset)
121{
122 const struct pt_regs_offset *roff;
123 for (roff = regoffset_table; roff->name != NULL; roff++)
124 if (roff->offset == offset)
125 return roff->name;
126 return NULL;
127}
128
129static const int arg_offs_table[] = {
130#ifdef CONFIG_X86_32
131 [0] = offsetof(struct pt_regs, ax),
132 [1] = offsetof(struct pt_regs, dx),
133 [2] = offsetof(struct pt_regs, cx)
134#else /* CONFIG_X86_64 */
135 [0] = offsetof(struct pt_regs, di),
136 [1] = offsetof(struct pt_regs, si),
137 [2] = offsetof(struct pt_regs, dx),
138 [3] = offsetof(struct pt_regs, cx),
139 [4] = offsetof(struct pt_regs, r8),
140 [5] = offsetof(struct pt_regs, r9)
141#endif
142};
143
144/*
145 * does not yet catch signals sent when the child dies.
146 * in exit.c or in signal.c.
147 */
148
149/*
150 * Determines which flags the user has access to [1 = access, 0 = no access].
151 */
152#define FLAG_MASK_32 ((unsigned long) \
153 (X86_EFLAGS_CF | X86_EFLAGS_PF | \
154 X86_EFLAGS_AF | X86_EFLAGS_ZF | \
155 X86_EFLAGS_SF | X86_EFLAGS_TF | \
156 X86_EFLAGS_DF | X86_EFLAGS_OF | \
157 X86_EFLAGS_RF | X86_EFLAGS_AC))
158
159/*
160 * Determines whether a value may be installed in a segment register.
161 */
162static inline bool invalid_selector(u16 value)
163{
164 return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
165}
166
167#ifdef CONFIG_X86_32
168
169#define FLAG_MASK FLAG_MASK_32
170
171/*
172 * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
173 * when it traps. The previous stack will be directly underneath the saved
174 * registers, and 'sp/ss' won't even have been saved. Thus the '®s->sp'.
175 *
176 * Now, if the stack is empty, '®s->sp' is out of range. In this
177 * case we try to take the previous stack. To always return a non-null
178 * stack pointer we fall back to regs as stack if no previous stack
179 * exists.
180 *
181 * This is valid only for kernel mode traps.
182 */
183unsigned long kernel_stack_pointer(struct pt_regs *regs)
184{
185 unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
186 unsigned long sp = (unsigned long)®s->sp;
187 u32 *prev_esp;
188
189 if (context == (sp & ~(THREAD_SIZE - 1)))
190 return sp;
191
192 prev_esp = (u32 *)(context);
193 if (prev_esp)
194 return (unsigned long)prev_esp;
195
196 return (unsigned long)regs;
197}
198EXPORT_SYMBOL_GPL(kernel_stack_pointer);
199
200static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
201{
202 BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
203 return ®s->bx + (regno >> 2);
204}
205
206static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
207{
208 /*
209 * Returning the value truncates it to 16 bits.
210 */
211 unsigned int retval;
212 if (offset != offsetof(struct user_regs_struct, gs))
213 retval = *pt_regs_access(task_pt_regs(task), offset);
214 else {
215 if (task == current)
216 retval = get_user_gs(task_pt_regs(task));
217 else
218 retval = task_user_gs(task);
219 }
220 return retval;
221}
222
223static int set_segment_reg(struct task_struct *task,
224 unsigned long offset, u16 value)
225{
226 /*
227 * The value argument was already truncated to 16 bits.
228 */
229 if (invalid_selector(value))
230 return -EIO;
231
232 /*
233 * For %cs and %ss we cannot permit a null selector.
234 * We can permit a bogus selector as long as it has USER_RPL.
235 * Null selectors are fine for other segment registers, but
236 * we will never get back to user mode with invalid %cs or %ss
237 * and will take the trap in iret instead. Much code relies
238 * on user_mode() to distinguish a user trap frame (which can
239 * safely use invalid selectors) from a kernel trap frame.
240 */
241 switch (offset) {
242 case offsetof(struct user_regs_struct, cs):
243 case offsetof(struct user_regs_struct, ss):
244 if (unlikely(value == 0))
245 return -EIO;
246
247 default:
248 *pt_regs_access(task_pt_regs(task), offset) = value;
249 break;
250
251 case offsetof(struct user_regs_struct, gs):
252 if (task == current)
253 set_user_gs(task_pt_regs(task), value);
254 else
255 task_user_gs(task) = value;
256 }
257
258 return 0;
259}
260
261#else /* CONFIG_X86_64 */
262
263#define FLAG_MASK (FLAG_MASK_32 | X86_EFLAGS_NT)
264
265static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
266{
267 BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
268 return ®s->r15 + (offset / sizeof(regs->r15));
269}
270
271static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
272{
273 /*
274 * Returning the value truncates it to 16 bits.
275 */
276 unsigned int seg;
277
278 switch (offset) {
279 case offsetof(struct user_regs_struct, fs):
280 if (task == current) {
281 /* Older gas can't assemble movq %?s,%r?? */
282 asm("movl %%fs,%0" : "=r" (seg));
283 return seg;
284 }
285 return task->thread.fsindex;
286 case offsetof(struct user_regs_struct, gs):
287 if (task == current) {
288 asm("movl %%gs,%0" : "=r" (seg));
289 return seg;
290 }
291 return task->thread.gsindex;
292 case offsetof(struct user_regs_struct, ds):
293 if (task == current) {
294 asm("movl %%ds,%0" : "=r" (seg));
295 return seg;
296 }
297 return task->thread.ds;
298 case offsetof(struct user_regs_struct, es):
299 if (task == current) {
300 asm("movl %%es,%0" : "=r" (seg));
301 return seg;
302 }
303 return task->thread.es;
304
305 case offsetof(struct user_regs_struct, cs):
306 case offsetof(struct user_regs_struct, ss):
307 break;
308 }
309 return *pt_regs_access(task_pt_regs(task), offset);
310}
311
312static int set_segment_reg(struct task_struct *task,
313 unsigned long offset, u16 value)
314{
315 /*
316 * The value argument was already truncated to 16 bits.
317 */
318 if (invalid_selector(value))
319 return -EIO;
320
321 switch (offset) {
322 case offsetof(struct user_regs_struct,fs):
323 /*
324 * If this is setting fs as for normal 64-bit use but
325 * setting fs_base has implicitly changed it, leave it.
326 */
327 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
328 task->thread.fs != 0) ||
329 (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
330 task->thread.fs == 0))
331 break;
332 task->thread.fsindex = value;
333 if (task == current)
334 loadsegment(fs, task->thread.fsindex);
335 break;
336 case offsetof(struct user_regs_struct,gs):
337 /*
338 * If this is setting gs as for normal 64-bit use but
339 * setting gs_base has implicitly changed it, leave it.
340 */
341 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
342 task->thread.gs != 0) ||
343 (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
344 task->thread.gs == 0))
345 break;
346 task->thread.gsindex = value;
347 if (task == current)
348 load_gs_index(task->thread.gsindex);
349 break;
350 case offsetof(struct user_regs_struct,ds):
351 task->thread.ds = value;
352 if (task == current)
353 loadsegment(ds, task->thread.ds);
354 break;
355 case offsetof(struct user_regs_struct,es):
356 task->thread.es = value;
357 if (task == current)
358 loadsegment(es, task->thread.es);
359 break;
360
361 /*
362 * Can't actually change these in 64-bit mode.
363 */
364 case offsetof(struct user_regs_struct,cs):
365 if (unlikely(value == 0))
366 return -EIO;
367#ifdef CONFIG_IA32_EMULATION
368 if (test_tsk_thread_flag(task, TIF_IA32))
369 task_pt_regs(task)->cs = value;
370#endif
371 break;
372 case offsetof(struct user_regs_struct,ss):
373 if (unlikely(value == 0))
374 return -EIO;
375#ifdef CONFIG_IA32_EMULATION
376 if (test_tsk_thread_flag(task, TIF_IA32))
377 task_pt_regs(task)->ss = value;
378#endif
379 break;
380 }
381
382 return 0;
383}
384
385#endif /* CONFIG_X86_32 */
386
387static unsigned long get_flags(struct task_struct *task)
388{
389 unsigned long retval = task_pt_regs(task)->flags;
390
391 /*
392 * If the debugger set TF, hide it from the readout.
393 */
394 if (test_tsk_thread_flag(task, TIF_FORCED_TF))
395 retval &= ~X86_EFLAGS_TF;
396
397 return retval;
398}
399
400static int set_flags(struct task_struct *task, unsigned long value)
401{
402 struct pt_regs *regs = task_pt_regs(task);
403
404 /*
405 * If the user value contains TF, mark that
406 * it was not "us" (the debugger) that set it.
407 * If not, make sure it stays set if we had.
408 */
409 if (value & X86_EFLAGS_TF)
410 clear_tsk_thread_flag(task, TIF_FORCED_TF);
411 else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
412 value |= X86_EFLAGS_TF;
413
414 regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
415
416 return 0;
417}
418
419static int putreg(struct task_struct *child,
420 unsigned long offset, unsigned long value)
421{
422 switch (offset) {
423 case offsetof(struct user_regs_struct, cs):
424 case offsetof(struct user_regs_struct, ds):
425 case offsetof(struct user_regs_struct, es):
426 case offsetof(struct user_regs_struct, fs):
427 case offsetof(struct user_regs_struct, gs):
428 case offsetof(struct user_regs_struct, ss):
429 return set_segment_reg(child, offset, value);
430
431 case offsetof(struct user_regs_struct, flags):
432 return set_flags(child, value);
433
434#ifdef CONFIG_X86_64
435 case offsetof(struct user_regs_struct,fs_base):
436 if (value >= TASK_SIZE_OF(child))
437 return -EIO;
438 /*
439 * When changing the segment base, use do_arch_prctl
440 * to set either thread.fs or thread.fsindex and the
441 * corresponding GDT slot.
442 */
443 if (child->thread.fs != value)
444 return do_arch_prctl(child, ARCH_SET_FS, value);
445 return 0;
446 case offsetof(struct user_regs_struct,gs_base):
447 /*
448 * Exactly the same here as the %fs handling above.
449 */
450 if (value >= TASK_SIZE_OF(child))
451 return -EIO;
452 if (child->thread.gs != value)
453 return do_arch_prctl(child, ARCH_SET_GS, value);
454 return 0;
455#endif
456 }
457
458 *pt_regs_access(task_pt_regs(child), offset) = value;
459 return 0;
460}
461
462static unsigned long getreg(struct task_struct *task, unsigned long offset)
463{
464 switch (offset) {
465 case offsetof(struct user_regs_struct, cs):
466 case offsetof(struct user_regs_struct, ds):
467 case offsetof(struct user_regs_struct, es):
468 case offsetof(struct user_regs_struct, fs):
469 case offsetof(struct user_regs_struct, gs):
470 case offsetof(struct user_regs_struct, ss):
471 return get_segment_reg(task, offset);
472
473 case offsetof(struct user_regs_struct, flags):
474 return get_flags(task);
475
476#ifdef CONFIG_X86_64
477 case offsetof(struct user_regs_struct, fs_base): {
478 /*
479 * do_arch_prctl may have used a GDT slot instead of
480 * the MSR. To userland, it appears the same either
481 * way, except the %fs segment selector might not be 0.
482 */
483 unsigned int seg = task->thread.fsindex;
484 if (task->thread.fs != 0)
485 return task->thread.fs;
486 if (task == current)
487 asm("movl %%fs,%0" : "=r" (seg));
488 if (seg != FS_TLS_SEL)
489 return 0;
490 return get_desc_base(&task->thread.tls_array[FS_TLS]);
491 }
492 case offsetof(struct user_regs_struct, gs_base): {
493 /*
494 * Exactly the same here as the %fs handling above.
495 */
496 unsigned int seg = task->thread.gsindex;
497 if (task->thread.gs != 0)
498 return task->thread.gs;
499 if (task == current)
500 asm("movl %%gs,%0" : "=r" (seg));
501 if (seg != GS_TLS_SEL)
502 return 0;
503 return get_desc_base(&task->thread.tls_array[GS_TLS]);
504 }
505#endif
506 }
507
508 return *pt_regs_access(task_pt_regs(task), offset);
509}
510
511static int genregs_get(struct task_struct *target,
512 const struct user_regset *regset,
513 unsigned int pos, unsigned int count,
514 void *kbuf, void __user *ubuf)
515{
516 if (kbuf) {
517 unsigned long *k = kbuf;
518 while (count >= sizeof(*k)) {
519 *k++ = getreg(target, pos);
520 count -= sizeof(*k);
521 pos += sizeof(*k);
522 }
523 } else {
524 unsigned long __user *u = ubuf;
525 while (count >= sizeof(*u)) {
526 if (__put_user(getreg(target, pos), u++))
527 return -EFAULT;
528 count -= sizeof(*u);
529 pos += sizeof(*u);
530 }
531 }
532
533 return 0;
534}
535
536static int genregs_set(struct task_struct *target,
537 const struct user_regset *regset,
538 unsigned int pos, unsigned int count,
539 const void *kbuf, const void __user *ubuf)
540{
541 int ret = 0;
542 if (kbuf) {
543 const unsigned long *k = kbuf;
544 while (count >= sizeof(*k) && !ret) {
545 ret = putreg(target, pos, *k++);
546 count -= sizeof(*k);
547 pos += sizeof(*k);
548 }
549 } else {
550 const unsigned long __user *u = ubuf;
551 while (count >= sizeof(*u) && !ret) {
552 unsigned long word;
553 ret = __get_user(word, u++);
554 if (ret)
555 break;
556 ret = putreg(target, pos, word);
557 count -= sizeof(*u);
558 pos += sizeof(*u);
559 }
560 }
561 return ret;
562}
563
564static void ptrace_triggered(struct perf_event *bp,
565 struct perf_sample_data *data,
566 struct pt_regs *regs)
567{
568 int i;
569 struct thread_struct *thread = &(current->thread);
570
571 /*
572 * Store in the virtual DR6 register the fact that the breakpoint
573 * was hit so the thread's debugger will see it.
574 */
575 for (i = 0; i < HBP_NUM; i++) {
576 if (thread->ptrace_bps[i] == bp)
577 break;
578 }
579
580 thread->debugreg6 |= (DR_TRAP0 << i);
581}
582
583/*
584 * Walk through every ptrace breakpoints for this thread and
585 * build the dr7 value on top of their attributes.
586 *
587 */
588static unsigned long ptrace_get_dr7(struct perf_event *bp[])
589{
590 int i;
591 int dr7 = 0;
592 struct arch_hw_breakpoint *info;
593
594 for (i = 0; i < HBP_NUM; i++) {
595 if (bp[i] && !bp[i]->attr.disabled) {
596 info = counter_arch_bp(bp[i]);
597 dr7 |= encode_dr7(i, info->len, info->type);
598 }
599 }
600
601 return dr7;
602}
603
604static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
605 int len, int type, bool disabled)
606{
607 int err, bp_len, bp_type;
608
609 err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
610 if (!err) {
611 attr->bp_len = bp_len;
612 attr->bp_type = bp_type;
613 attr->disabled = disabled;
614 }
615
616 return err;
617}
618
619static struct perf_event *
620ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
621 unsigned long addr, bool disabled)
622{
623 struct perf_event_attr attr;
624 int err;
625
626 ptrace_breakpoint_init(&attr);
627 attr.bp_addr = addr;
628
629 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
630 if (err)
631 return ERR_PTR(err);
632
633 return register_user_hw_breakpoint(&attr, ptrace_triggered,
634 NULL, tsk);
635}
636
637static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
638 int disabled)
639{
640 struct perf_event_attr attr = bp->attr;
641 int err;
642
643 err = ptrace_fill_bp_fields(&attr, len, type, disabled);
644 if (err)
645 return err;
646
647 return modify_user_hw_breakpoint(bp, &attr);
648}
649
650/*
651 * Handle ptrace writes to debug register 7.
652 */
653static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
654{
655 struct thread_struct *thread = &tsk->thread;
656 unsigned long old_dr7;
657 bool second_pass = false;
658 int i, rc, ret = 0;
659
660 data &= ~DR_CONTROL_RESERVED;
661 old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
662
663restore:
664 rc = 0;
665 for (i = 0; i < HBP_NUM; i++) {
666 unsigned len, type;
667 bool disabled = !decode_dr7(data, i, &len, &type);
668 struct perf_event *bp = thread->ptrace_bps[i];
669
670 if (!bp) {
671 if (disabled)
672 continue;
673
674 bp = ptrace_register_breakpoint(tsk,
675 len, type, 0, disabled);
676 if (IS_ERR(bp)) {
677 rc = PTR_ERR(bp);
678 break;
679 }
680
681 thread->ptrace_bps[i] = bp;
682 continue;
683 }
684
685 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
686 if (rc)
687 break;
688 }
689
690 /* Restore if the first pass failed, second_pass shouldn't fail. */
691 if (rc && !WARN_ON(second_pass)) {
692 ret = rc;
693 data = old_dr7;
694 second_pass = true;
695 goto restore;
696 }
697
698 return ret;
699}
700
701/*
702 * Handle PTRACE_PEEKUSR calls for the debug register area.
703 */
704static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
705{
706 struct thread_struct *thread = &tsk->thread;
707 unsigned long val = 0;
708
709 if (n < HBP_NUM) {
710 struct perf_event *bp = thread->ptrace_bps[n];
711
712 if (bp)
713 val = bp->hw.info.address;
714 } else if (n == 6) {
715 val = thread->debugreg6;
716 } else if (n == 7) {
717 val = thread->ptrace_dr7;
718 }
719 return val;
720}
721
722static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
723 unsigned long addr)
724{
725 struct thread_struct *t = &tsk->thread;
726 struct perf_event *bp = t->ptrace_bps[nr];
727 int err = 0;
728
729 if (!bp) {
730 /*
731 * Put stub len and type to create an inactive but correct bp.
732 *
733 * CHECKME: the previous code returned -EIO if the addr wasn't
734 * a valid task virtual addr. The new one will return -EINVAL in
735 * this case.
736 * -EINVAL may be what we want for in-kernel breakpoints users,
737 * but -EIO looks better for ptrace, since we refuse a register
738 * writing for the user. And anyway this is the previous
739 * behaviour.
740 */
741 bp = ptrace_register_breakpoint(tsk,
742 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
743 addr, true);
744 if (IS_ERR(bp))
745 err = PTR_ERR(bp);
746 else
747 t->ptrace_bps[nr] = bp;
748 } else {
749 struct perf_event_attr attr = bp->attr;
750
751 attr.bp_addr = addr;
752 err = modify_user_hw_breakpoint(bp, &attr);
753 }
754
755 return err;
756}
757
758/*
759 * Handle PTRACE_POKEUSR calls for the debug register area.
760 */
761static int ptrace_set_debugreg(struct task_struct *tsk, int n,
762 unsigned long val)
763{
764 struct thread_struct *thread = &tsk->thread;
765 /* There are no DR4 or DR5 registers */
766 int rc = -EIO;
767
768 if (n < HBP_NUM) {
769 rc = ptrace_set_breakpoint_addr(tsk, n, val);
770 } else if (n == 6) {
771 thread->debugreg6 = val;
772 rc = 0;
773 } else if (n == 7) {
774 rc = ptrace_write_dr7(tsk, val);
775 if (!rc)
776 thread->ptrace_dr7 = val;
777 }
778 return rc;
779}
780
781/*
782 * These access the current or another (stopped) task's io permission
783 * bitmap for debugging or core dump.
784 */
785static int ioperm_active(struct task_struct *target,
786 const struct user_regset *regset)
787{
788 return target->thread.io_bitmap_max / regset->size;
789}
790
791static int ioperm_get(struct task_struct *target,
792 const struct user_regset *regset,
793 unsigned int pos, unsigned int count,
794 void *kbuf, void __user *ubuf)
795{
796 if (!target->thread.io_bitmap_ptr)
797 return -ENXIO;
798
799 return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
800 target->thread.io_bitmap_ptr,
801 0, IO_BITMAP_BYTES);
802}
803
804/*
805 * Called by kernel/ptrace.c when detaching..
806 *
807 * Make sure the single step bit is not set.
808 */
809void ptrace_disable(struct task_struct *child)
810{
811 user_disable_single_step(child);
812#ifdef TIF_SYSCALL_EMU
813 clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
814#endif
815}
816
817#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
818static const struct user_regset_view user_x86_32_view; /* Initialized below. */
819#endif
820
821long arch_ptrace(struct task_struct *child, long request,
822 unsigned long addr, unsigned long data)
823{
824 int ret;
825 unsigned long __user *datap = (unsigned long __user *)data;
826
827 switch (request) {
828 /* read the word at location addr in the USER area. */
829 case PTRACE_PEEKUSR: {
830 unsigned long tmp;
831
832 ret = -EIO;
833 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
834 break;
835
836 tmp = 0; /* Default return condition */
837 if (addr < sizeof(struct user_regs_struct))
838 tmp = getreg(child, addr);
839 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
840 addr <= offsetof(struct user, u_debugreg[7])) {
841 addr -= offsetof(struct user, u_debugreg[0]);
842 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
843 }
844 ret = put_user(tmp, datap);
845 break;
846 }
847
848 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
849 ret = -EIO;
850 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
851 break;
852
853 if (addr < sizeof(struct user_regs_struct))
854 ret = putreg(child, addr, data);
855 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
856 addr <= offsetof(struct user, u_debugreg[7])) {
857 addr -= offsetof(struct user, u_debugreg[0]);
858 ret = ptrace_set_debugreg(child,
859 addr / sizeof(data), data);
860 }
861 break;
862
863 case PTRACE_GETREGS: /* Get all gp regs from the child. */
864 return copy_regset_to_user(child,
865 task_user_regset_view(current),
866 REGSET_GENERAL,
867 0, sizeof(struct user_regs_struct),
868 datap);
869
870 case PTRACE_SETREGS: /* Set all gp regs in the child. */
871 return copy_regset_from_user(child,
872 task_user_regset_view(current),
873 REGSET_GENERAL,
874 0, sizeof(struct user_regs_struct),
875 datap);
876
877 case PTRACE_GETFPREGS: /* Get the child FPU state. */
878 return copy_regset_to_user(child,
879 task_user_regset_view(current),
880 REGSET_FP,
881 0, sizeof(struct user_i387_struct),
882 datap);
883
884 case PTRACE_SETFPREGS: /* Set the child FPU state. */
885 return copy_regset_from_user(child,
886 task_user_regset_view(current),
887 REGSET_FP,
888 0, sizeof(struct user_i387_struct),
889 datap);
890
891#ifdef CONFIG_X86_32
892 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
893 return copy_regset_to_user(child, &user_x86_32_view,
894 REGSET_XFP,
895 0, sizeof(struct user_fxsr_struct),
896 datap) ? -EIO : 0;
897
898 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
899 return copy_regset_from_user(child, &user_x86_32_view,
900 REGSET_XFP,
901 0, sizeof(struct user_fxsr_struct),
902 datap) ? -EIO : 0;
903#endif
904
905#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
906 case PTRACE_GET_THREAD_AREA:
907 if ((int) addr < 0)
908 return -EIO;
909 ret = do_get_thread_area(child, addr,
910 (struct user_desc __user *)data);
911 break;
912
913 case PTRACE_SET_THREAD_AREA:
914 if ((int) addr < 0)
915 return -EIO;
916 ret = do_set_thread_area(child, addr,
917 (struct user_desc __user *)data, 0);
918 break;
919#endif
920
921#ifdef CONFIG_X86_64
922 /* normal 64bit interface to access TLS data.
923 Works just like arch_prctl, except that the arguments
924 are reversed. */
925 case PTRACE_ARCH_PRCTL:
926 ret = do_arch_prctl(child, data, addr);
927 break;
928#endif
929
930 default:
931 ret = ptrace_request(child, request, addr, data);
932 break;
933 }
934
935 return ret;
936}
937
938#ifdef CONFIG_IA32_EMULATION
939
940#include <linux/compat.h>
941#include <linux/syscalls.h>
942#include <asm/ia32.h>
943#include <asm/user32.h>
944
945#define R32(l,q) \
946 case offsetof(struct user32, regs.l): \
947 regs->q = value; break
948
949#define SEG32(rs) \
950 case offsetof(struct user32, regs.rs): \
951 return set_segment_reg(child, \
952 offsetof(struct user_regs_struct, rs), \
953 value); \
954 break
955
956static int putreg32(struct task_struct *child, unsigned regno, u32 value)
957{
958 struct pt_regs *regs = task_pt_regs(child);
959
960 switch (regno) {
961
962 SEG32(cs);
963 SEG32(ds);
964 SEG32(es);
965 SEG32(fs);
966 SEG32(gs);
967 SEG32(ss);
968
969 R32(ebx, bx);
970 R32(ecx, cx);
971 R32(edx, dx);
972 R32(edi, di);
973 R32(esi, si);
974 R32(ebp, bp);
975 R32(eax, ax);
976 R32(eip, ip);
977 R32(esp, sp);
978
979 case offsetof(struct user32, regs.orig_eax):
980 /*
981 * A 32-bit debugger setting orig_eax means to restore
982 * the state of the task restarting a 32-bit syscall.
983 * Make sure we interpret the -ERESTART* codes correctly
984 * in case the task is not actually still sitting at the
985 * exit from a 32-bit syscall with TS_COMPAT still set.
986 */
987 regs->orig_ax = value;
988 if (syscall_get_nr(child, regs) >= 0)
989 task_thread_info(child)->status |= TS_COMPAT;
990 break;
991
992 case offsetof(struct user32, regs.eflags):
993 return set_flags(child, value);
994
995 case offsetof(struct user32, u_debugreg[0]) ...
996 offsetof(struct user32, u_debugreg[7]):
997 regno -= offsetof(struct user32, u_debugreg[0]);
998 return ptrace_set_debugreg(child, regno / 4, value);
999
1000 default:
1001 if (regno > sizeof(struct user32) || (regno & 3))
1002 return -EIO;
1003
1004 /*
1005 * Other dummy fields in the virtual user structure
1006 * are ignored
1007 */
1008 break;
1009 }
1010 return 0;
1011}
1012
1013#undef R32
1014#undef SEG32
1015
1016#define R32(l,q) \
1017 case offsetof(struct user32, regs.l): \
1018 *val = regs->q; break
1019
1020#define SEG32(rs) \
1021 case offsetof(struct user32, regs.rs): \
1022 *val = get_segment_reg(child, \
1023 offsetof(struct user_regs_struct, rs)); \
1024 break
1025
1026static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1027{
1028 struct pt_regs *regs = task_pt_regs(child);
1029
1030 switch (regno) {
1031
1032 SEG32(ds);
1033 SEG32(es);
1034 SEG32(fs);
1035 SEG32(gs);
1036
1037 R32(cs, cs);
1038 R32(ss, ss);
1039 R32(ebx, bx);
1040 R32(ecx, cx);
1041 R32(edx, dx);
1042 R32(edi, di);
1043 R32(esi, si);
1044 R32(ebp, bp);
1045 R32(eax, ax);
1046 R32(orig_eax, orig_ax);
1047 R32(eip, ip);
1048 R32(esp, sp);
1049
1050 case offsetof(struct user32, regs.eflags):
1051 *val = get_flags(child);
1052 break;
1053
1054 case offsetof(struct user32, u_debugreg[0]) ...
1055 offsetof(struct user32, u_debugreg[7]):
1056 regno -= offsetof(struct user32, u_debugreg[0]);
1057 *val = ptrace_get_debugreg(child, regno / 4);
1058 break;
1059
1060 default:
1061 if (regno > sizeof(struct user32) || (regno & 3))
1062 return -EIO;
1063
1064 /*
1065 * Other dummy fields in the virtual user structure
1066 * are ignored
1067 */
1068 *val = 0;
1069 break;
1070 }
1071 return 0;
1072}
1073
1074#undef R32
1075#undef SEG32
1076
1077static int genregs32_get(struct task_struct *target,
1078 const struct user_regset *regset,
1079 unsigned int pos, unsigned int count,
1080 void *kbuf, void __user *ubuf)
1081{
1082 if (kbuf) {
1083 compat_ulong_t *k = kbuf;
1084 while (count >= sizeof(*k)) {
1085 getreg32(target, pos, k++);
1086 count -= sizeof(*k);
1087 pos += sizeof(*k);
1088 }
1089 } else {
1090 compat_ulong_t __user *u = ubuf;
1091 while (count >= sizeof(*u)) {
1092 compat_ulong_t word;
1093 getreg32(target, pos, &word);
1094 if (__put_user(word, u++))
1095 return -EFAULT;
1096 count -= sizeof(*u);
1097 pos += sizeof(*u);
1098 }
1099 }
1100
1101 return 0;
1102}
1103
1104static int genregs32_set(struct task_struct *target,
1105 const struct user_regset *regset,
1106 unsigned int pos, unsigned int count,
1107 const void *kbuf, const void __user *ubuf)
1108{
1109 int ret = 0;
1110 if (kbuf) {
1111 const compat_ulong_t *k = kbuf;
1112 while (count >= sizeof(*k) && !ret) {
1113 ret = putreg32(target, pos, *k++);
1114 count -= sizeof(*k);
1115 pos += sizeof(*k);
1116 }
1117 } else {
1118 const compat_ulong_t __user *u = ubuf;
1119 while (count >= sizeof(*u) && !ret) {
1120 compat_ulong_t word;
1121 ret = __get_user(word, u++);
1122 if (ret)
1123 break;
1124 ret = putreg32(target, pos, word);
1125 count -= sizeof(*u);
1126 pos += sizeof(*u);
1127 }
1128 }
1129 return ret;
1130}
1131
1132#ifdef CONFIG_X86_X32_ABI
1133static long x32_arch_ptrace(struct task_struct *child,
1134 compat_long_t request, compat_ulong_t caddr,
1135 compat_ulong_t cdata)
1136{
1137 unsigned long addr = caddr;
1138 unsigned long data = cdata;
1139 void __user *datap = compat_ptr(data);
1140 int ret;
1141
1142 switch (request) {
1143 /* Read 32bits at location addr in the USER area. Only allow
1144 to return the lower 32bits of segment and debug registers. */
1145 case PTRACE_PEEKUSR: {
1146 u32 tmp;
1147
1148 ret = -EIO;
1149 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1150 addr < offsetof(struct user_regs_struct, cs))
1151 break;
1152
1153 tmp = 0; /* Default return condition */
1154 if (addr < sizeof(struct user_regs_struct))
1155 tmp = getreg(child, addr);
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 tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1160 }
1161 ret = put_user(tmp, (__u32 __user *)datap);
1162 break;
1163 }
1164
1165 /* Write the word at location addr in the USER area. Only allow
1166 to update segment and debug registers with the upper 32bits
1167 zero-extended. */
1168 case PTRACE_POKEUSR:
1169 ret = -EIO;
1170 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1171 addr < offsetof(struct user_regs_struct, cs))
1172 break;
1173
1174 if (addr < sizeof(struct user_regs_struct))
1175 ret = putreg(child, addr, data);
1176 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1177 addr <= offsetof(struct user, u_debugreg[7])) {
1178 addr -= offsetof(struct user, u_debugreg[0]);
1179 ret = ptrace_set_debugreg(child,
1180 addr / sizeof(data), data);
1181 }
1182 break;
1183
1184 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1185 return copy_regset_to_user(child,
1186 task_user_regset_view(current),
1187 REGSET_GENERAL,
1188 0, sizeof(struct user_regs_struct),
1189 datap);
1190
1191 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1192 return copy_regset_from_user(child,
1193 task_user_regset_view(current),
1194 REGSET_GENERAL,
1195 0, sizeof(struct user_regs_struct),
1196 datap);
1197
1198 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1199 return copy_regset_to_user(child,
1200 task_user_regset_view(current),
1201 REGSET_FP,
1202 0, sizeof(struct user_i387_struct),
1203 datap);
1204
1205 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1206 return copy_regset_from_user(child,
1207 task_user_regset_view(current),
1208 REGSET_FP,
1209 0, sizeof(struct user_i387_struct),
1210 datap);
1211
1212 default:
1213 return compat_ptrace_request(child, request, addr, data);
1214 }
1215
1216 return ret;
1217}
1218#endif
1219
1220long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1221 compat_ulong_t caddr, compat_ulong_t cdata)
1222{
1223 unsigned long addr = caddr;
1224 unsigned long data = cdata;
1225 void __user *datap = compat_ptr(data);
1226 int ret;
1227 __u32 val;
1228
1229#ifdef CONFIG_X86_X32_ABI
1230 if (!is_ia32_task())
1231 return x32_arch_ptrace(child, request, caddr, cdata);
1232#endif
1233
1234 switch (request) {
1235 case PTRACE_PEEKUSR:
1236 ret = getreg32(child, addr, &val);
1237 if (ret == 0)
1238 ret = put_user(val, (__u32 __user *)datap);
1239 break;
1240
1241 case PTRACE_POKEUSR:
1242 ret = putreg32(child, addr, data);
1243 break;
1244
1245 case PTRACE_GETREGS: /* Get all gp regs from the child. */
1246 return copy_regset_to_user(child, &user_x86_32_view,
1247 REGSET_GENERAL,
1248 0, sizeof(struct user_regs_struct32),
1249 datap);
1250
1251 case PTRACE_SETREGS: /* Set all gp regs in the child. */
1252 return copy_regset_from_user(child, &user_x86_32_view,
1253 REGSET_GENERAL, 0,
1254 sizeof(struct user_regs_struct32),
1255 datap);
1256
1257 case PTRACE_GETFPREGS: /* Get the child FPU state. */
1258 return copy_regset_to_user(child, &user_x86_32_view,
1259 REGSET_FP, 0,
1260 sizeof(struct user_i387_ia32_struct),
1261 datap);
1262
1263 case PTRACE_SETFPREGS: /* Set the child FPU state. */
1264 return copy_regset_from_user(
1265 child, &user_x86_32_view, REGSET_FP,
1266 0, sizeof(struct user_i387_ia32_struct), datap);
1267
1268 case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1269 return copy_regset_to_user(child, &user_x86_32_view,
1270 REGSET_XFP, 0,
1271 sizeof(struct user32_fxsr_struct),
1272 datap);
1273
1274 case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1275 return copy_regset_from_user(child, &user_x86_32_view,
1276 REGSET_XFP, 0,
1277 sizeof(struct user32_fxsr_struct),
1278 datap);
1279
1280 case PTRACE_GET_THREAD_AREA:
1281 case PTRACE_SET_THREAD_AREA:
1282 return arch_ptrace(child, request, addr, data);
1283
1284 default:
1285 return compat_ptrace_request(child, request, addr, data);
1286 }
1287
1288 return ret;
1289}
1290
1291#endif /* CONFIG_IA32_EMULATION */
1292
1293#ifdef CONFIG_X86_64
1294
1295static struct user_regset x86_64_regsets[] __read_mostly = {
1296 [REGSET_GENERAL] = {
1297 .core_note_type = NT_PRSTATUS,
1298 .n = sizeof(struct user_regs_struct) / sizeof(long),
1299 .size = sizeof(long), .align = sizeof(long),
1300 .get = genregs_get, .set = genregs_set
1301 },
1302 [REGSET_FP] = {
1303 .core_note_type = NT_PRFPREG,
1304 .n = sizeof(struct user_i387_struct) / sizeof(long),
1305 .size = sizeof(long), .align = sizeof(long),
1306 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1307 },
1308 [REGSET_XSTATE] = {
1309 .core_note_type = NT_X86_XSTATE,
1310 .size = sizeof(u64), .align = sizeof(u64),
1311 .active = xstateregs_active, .get = xstateregs_get,
1312 .set = xstateregs_set
1313 },
1314 [REGSET_IOPERM64] = {
1315 .core_note_type = NT_386_IOPERM,
1316 .n = IO_BITMAP_LONGS,
1317 .size = sizeof(long), .align = sizeof(long),
1318 .active = ioperm_active, .get = ioperm_get
1319 },
1320};
1321
1322static const struct user_regset_view user_x86_64_view = {
1323 .name = "x86_64", .e_machine = EM_X86_64,
1324 .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1325};
1326
1327#else /* CONFIG_X86_32 */
1328
1329#define user_regs_struct32 user_regs_struct
1330#define genregs32_get genregs_get
1331#define genregs32_set genregs_set
1332
1333#endif /* CONFIG_X86_64 */
1334
1335#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1336static struct user_regset x86_32_regsets[] __read_mostly = {
1337 [REGSET_GENERAL] = {
1338 .core_note_type = NT_PRSTATUS,
1339 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1340 .size = sizeof(u32), .align = sizeof(u32),
1341 .get = genregs32_get, .set = genregs32_set
1342 },
1343 [REGSET_FP] = {
1344 .core_note_type = NT_PRFPREG,
1345 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1346 .size = sizeof(u32), .align = sizeof(u32),
1347 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1348 },
1349 [REGSET_XFP] = {
1350 .core_note_type = NT_PRXFPREG,
1351 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1352 .size = sizeof(u32), .align = sizeof(u32),
1353 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1354 },
1355 [REGSET_XSTATE] = {
1356 .core_note_type = NT_X86_XSTATE,
1357 .size = sizeof(u64), .align = sizeof(u64),
1358 .active = xstateregs_active, .get = xstateregs_get,
1359 .set = xstateregs_set
1360 },
1361 [REGSET_TLS] = {
1362 .core_note_type = NT_386_TLS,
1363 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1364 .size = sizeof(struct user_desc),
1365 .align = sizeof(struct user_desc),
1366 .active = regset_tls_active,
1367 .get = regset_tls_get, .set = regset_tls_set
1368 },
1369 [REGSET_IOPERM32] = {
1370 .core_note_type = NT_386_IOPERM,
1371 .n = IO_BITMAP_BYTES / sizeof(u32),
1372 .size = sizeof(u32), .align = sizeof(u32),
1373 .active = ioperm_active, .get = ioperm_get
1374 },
1375};
1376
1377static const struct user_regset_view user_x86_32_view = {
1378 .name = "i386", .e_machine = EM_386,
1379 .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1380};
1381#endif
1382
1383/*
1384 * This represents bytes 464..511 in the memory layout exported through
1385 * the REGSET_XSTATE interface.
1386 */
1387u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1388
1389void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1390{
1391#ifdef CONFIG_X86_64
1392 x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1393#endif
1394#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1395 x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1396#endif
1397 xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1398}
1399
1400const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1401{
1402#ifdef CONFIG_IA32_EMULATION
1403 if (test_tsk_thread_flag(task, TIF_IA32))
1404#endif
1405#if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1406 return &user_x86_32_view;
1407#endif
1408#ifdef CONFIG_X86_64
1409 return &user_x86_64_view;
1410#endif
1411}
1412
1413static void fill_sigtrap_info(struct task_struct *tsk,
1414 struct pt_regs *regs,
1415 int error_code, int si_code,
1416 struct siginfo *info)
1417{
1418 tsk->thread.trap_nr = X86_TRAP_DB;
1419 tsk->thread.error_code = error_code;
1420
1421 memset(info, 0, sizeof(*info));
1422 info->si_signo = SIGTRAP;
1423 info->si_code = si_code;
1424 info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1425}
1426
1427void user_single_step_siginfo(struct task_struct *tsk,
1428 struct pt_regs *regs,
1429 struct siginfo *info)
1430{
1431 fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1432}
1433
1434void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1435 int error_code, int si_code)
1436{
1437 struct siginfo info;
1438
1439 fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1440 /* Send us the fake SIGTRAP */
1441 force_sig_info(SIGTRAP, &info, tsk);
1442}
1443
1444
1445#ifdef CONFIG_X86_32
1446# define IS_IA32 1
1447#elif defined CONFIG_IA32_EMULATION
1448# define IS_IA32 is_compat_task()
1449#else
1450# define IS_IA32 0
1451#endif
1452
1453/*
1454 * We must return the syscall number to actually look up in the table.
1455 * This can be -1L to skip running any syscall at all.
1456 */
1457long syscall_trace_enter(struct pt_regs *regs)
1458{
1459 long ret = 0;
1460
1461 user_exit();
1462
1463 /*
1464 * If we stepped into a sysenter/syscall insn, it trapped in
1465 * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1466 * If user-mode had set TF itself, then it's still clear from
1467 * do_debug() and we need to set it again to restore the user
1468 * state. If we entered on the slow path, TF was already set.
1469 */
1470 if (test_thread_flag(TIF_SINGLESTEP))
1471 regs->flags |= X86_EFLAGS_TF;
1472
1473 /* do the secure computing check first */
1474 if (secure_computing(regs->orig_ax)) {
1475 /* seccomp failures shouldn't expose any additional code. */
1476 ret = -1L;
1477 goto out;
1478 }
1479
1480 if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1481 ret = -1L;
1482
1483 if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1484 tracehook_report_syscall_entry(regs))
1485 ret = -1L;
1486
1487 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1488 trace_sys_enter(regs, regs->orig_ax);
1489
1490 if (IS_IA32)
1491 audit_syscall_entry(AUDIT_ARCH_I386,
1492 regs->orig_ax,
1493 regs->bx, regs->cx,
1494 regs->dx, regs->si);
1495#ifdef CONFIG_X86_64
1496 else
1497 audit_syscall_entry(AUDIT_ARCH_X86_64,
1498 regs->orig_ax,
1499 regs->di, regs->si,
1500 regs->dx, regs->r10);
1501#endif
1502
1503out:
1504 return ret ?: regs->orig_ax;
1505}
1506
1507void syscall_trace_leave(struct pt_regs *regs)
1508{
1509 bool step;
1510
1511 /*
1512 * We may come here right after calling schedule_user()
1513 * or do_notify_resume(), in which case we can be in RCU
1514 * user mode.
1515 */
1516 user_exit();
1517
1518 audit_syscall_exit(regs);
1519
1520 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1521 trace_sys_exit(regs, regs->ax);
1522
1523 /*
1524 * If TIF_SYSCALL_EMU is set, we only get here because of
1525 * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1526 * We already reported this syscall instruction in
1527 * syscall_trace_enter().
1528 */
1529 step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1530 !test_thread_flag(TIF_SYSCALL_EMU);
1531 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1532 tracehook_report_syscall_exit(regs, step);
1533
1534 user_enter();
1535}