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1/* By Ross Biro 1/23/92 */
2/*
3 * Pentium III FXSR, SSE support
4 * Gareth Hughes <gareth@valinux.com>, May 2000
5 */
6
7#include <linux/kernel.h>
8#include <linux/sched.h>
9#include <linux/mm.h>
10#include <linux/smp.h>
11#include <linux/errno.h>
12#include <linux/slab.h>
13#include <linux/ptrace.h>
14#include <linux/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}
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}