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
46 enum 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
56 struct 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
64 static 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 */
regs_query_register_offset(const char * name)104 int 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 */
regs_query_register_name(unsigned int offset)120 const 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
129 static 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 */
invalid_selector(u16 value)162 static 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 */
kernel_stack_pointer(struct pt_regs * regs)183 unsigned 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 }
198 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
199
pt_regs_access(struct pt_regs * regs,unsigned long regno)200 static 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
get_segment_reg(struct task_struct * task,unsigned long offset)206 static 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
set_segment_reg(struct task_struct * task,unsigned long offset,u16 value)223 static 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
pt_regs_access(struct pt_regs * regs,unsigned long offset)265 static 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
get_segment_reg(struct task_struct * task,unsigned long offset)271 static 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
set_segment_reg(struct task_struct * task,unsigned long offset,u16 value)312 static 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
get_flags(struct task_struct * task)387 static 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
set_flags(struct task_struct * task,unsigned long value)400 static 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
putreg(struct task_struct * child,unsigned long offset,unsigned long value)419 static 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
getreg(struct task_struct * task,unsigned long offset)462 static 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
genregs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)511 static 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
genregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)536 static 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
ptrace_triggered(struct perf_event * bp,struct perf_sample_data * data,struct pt_regs * regs)564 static 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 */
ptrace_get_dr7(struct perf_event * bp[])588 static 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
ptrace_fill_bp_fields(struct perf_event_attr * attr,int len,int type,bool disabled)604 static 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
619 static struct perf_event *
ptrace_register_breakpoint(struct task_struct * tsk,int len,int type,unsigned long addr,bool disabled)620 ptrace_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
ptrace_modify_breakpoint(struct perf_event * bp,int len,int type,int disabled)637 static 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 */
ptrace_write_dr7(struct task_struct * tsk,unsigned long data)653 static 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
663 restore:
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 */
ptrace_get_debugreg(struct task_struct * tsk,int n)704 static 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
ptrace_set_breakpoint_addr(struct task_struct * tsk,int nr,unsigned long addr)722 static 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 */
ptrace_set_debugreg(struct task_struct * tsk,int n,unsigned long val)761 static 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 */
ioperm_active(struct task_struct * target,const struct user_regset * regset)785 static 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
ioperm_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)791 static 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 */
ptrace_disable(struct task_struct * child)809 void 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
818 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
819 #endif
820
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)821 long 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
putreg32(struct task_struct * child,unsigned regno,u32 value)956 static 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
getreg32(struct task_struct * child,unsigned regno,u32 * val)1026 static 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
genregs32_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)1077 static 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
genregs32_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)1104 static 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
x32_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)1133 static 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
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)1220 long 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
1295 static 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
1322 static 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
1336 static 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
1377 static 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 */
1387 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1388
update_regset_xstate_info(unsigned int size,u64 xstate_mask)1389 void 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
task_user_regset_view(struct task_struct * task)1400 const 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
fill_sigtrap_info(struct task_struct * tsk,struct pt_regs * regs,int error_code,int si_code,struct siginfo * info)1413 static 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
user_single_step_siginfo(struct task_struct * tsk,struct pt_regs * regs,struct siginfo * info)1427 void 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
send_sigtrap(struct task_struct * tsk,struct pt_regs * regs,int error_code,int si_code)1434 void 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
do_audit_syscall_entry(struct pt_regs * regs,u32 arch)1444 static void do_audit_syscall_entry(struct pt_regs *regs, u32 arch)
1445 {
1446 #ifdef CONFIG_X86_64
1447 if (arch == AUDIT_ARCH_X86_64) {
1448 audit_syscall_entry(regs->orig_ax, regs->di,
1449 regs->si, regs->dx, regs->r10);
1450 } else
1451 #endif
1452 {
1453 audit_syscall_entry(regs->orig_ax, regs->bx,
1454 regs->cx, regs->dx, regs->si);
1455 }
1456 }
1457
1458 /*
1459 * We can return 0 to resume the syscall or anything else to go to phase
1460 * 2. If we resume the syscall, we need to put something appropriate in
1461 * regs->orig_ax.
1462 *
1463 * NB: We don't have full pt_regs here, but regs->orig_ax and regs->ax
1464 * are fully functional.
1465 *
1466 * For phase 2's benefit, our return value is:
1467 * 0: resume the syscall
1468 * 1: go to phase 2; no seccomp phase 2 needed
1469 * anything else: go to phase 2; pass return value to seccomp
1470 */
syscall_trace_enter_phase1(struct pt_regs * regs,u32 arch)1471 unsigned long syscall_trace_enter_phase1(struct pt_regs *regs, u32 arch)
1472 {
1473 unsigned long ret = 0;
1474 u32 work;
1475
1476 BUG_ON(regs != task_pt_regs(current));
1477
1478 work = ACCESS_ONCE(current_thread_info()->flags) &
1479 _TIF_WORK_SYSCALL_ENTRY;
1480
1481 /*
1482 * If TIF_NOHZ is set, we are required to call user_exit() before
1483 * doing anything that could touch RCU.
1484 */
1485 if (work & _TIF_NOHZ) {
1486 user_exit();
1487 work &= ~_TIF_NOHZ;
1488 }
1489
1490 #ifdef CONFIG_SECCOMP
1491 /*
1492 * Do seccomp first -- it should minimize exposure of other
1493 * code, and keeping seccomp fast is probably more valuable
1494 * than the rest of this.
1495 */
1496 if (work & _TIF_SECCOMP) {
1497 struct seccomp_data sd;
1498
1499 sd.arch = arch;
1500 sd.nr = regs->orig_ax;
1501 sd.instruction_pointer = regs->ip;
1502 #ifdef CONFIG_X86_64
1503 if (arch == AUDIT_ARCH_X86_64) {
1504 sd.args[0] = regs->di;
1505 sd.args[1] = regs->si;
1506 sd.args[2] = regs->dx;
1507 sd.args[3] = regs->r10;
1508 sd.args[4] = regs->r8;
1509 sd.args[5] = regs->r9;
1510 } else
1511 #endif
1512 {
1513 sd.args[0] = regs->bx;
1514 sd.args[1] = regs->cx;
1515 sd.args[2] = regs->dx;
1516 sd.args[3] = regs->si;
1517 sd.args[4] = regs->di;
1518 sd.args[5] = regs->bp;
1519 }
1520
1521 BUILD_BUG_ON(SECCOMP_PHASE1_OK != 0);
1522 BUILD_BUG_ON(SECCOMP_PHASE1_SKIP != 1);
1523
1524 ret = seccomp_phase1(&sd);
1525 if (ret == SECCOMP_PHASE1_SKIP) {
1526 regs->orig_ax = -1;
1527 ret = 0;
1528 } else if (ret != SECCOMP_PHASE1_OK) {
1529 return ret; /* Go directly to phase 2 */
1530 }
1531
1532 work &= ~_TIF_SECCOMP;
1533 }
1534 #endif
1535
1536 /* Do our best to finish without phase 2. */
1537 if (work == 0)
1538 return ret; /* seccomp and/or nohz only (ret == 0 here) */
1539
1540 #ifdef CONFIG_AUDITSYSCALL
1541 if (work == _TIF_SYSCALL_AUDIT) {
1542 /*
1543 * If there is no more work to be done except auditing,
1544 * then audit in phase 1. Phase 2 always audits, so, if
1545 * we audit here, then we can't go on to phase 2.
1546 */
1547 do_audit_syscall_entry(regs, arch);
1548 return 0;
1549 }
1550 #endif
1551
1552 return 1; /* Something is enabled that we can't handle in phase 1 */
1553 }
1554
1555 /* Returns the syscall nr to run (which should match regs->orig_ax). */
syscall_trace_enter_phase2(struct pt_regs * regs,u32 arch,unsigned long phase1_result)1556 long syscall_trace_enter_phase2(struct pt_regs *regs, u32 arch,
1557 unsigned long phase1_result)
1558 {
1559 long ret = 0;
1560 u32 work = ACCESS_ONCE(current_thread_info()->flags) &
1561 _TIF_WORK_SYSCALL_ENTRY;
1562
1563 BUG_ON(regs != task_pt_regs(current));
1564
1565 /*
1566 * If we stepped into a sysenter/syscall insn, it trapped in
1567 * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1568 * If user-mode had set TF itself, then it's still clear from
1569 * do_debug() and we need to set it again to restore the user
1570 * state. If we entered on the slow path, TF was already set.
1571 */
1572 if (work & _TIF_SINGLESTEP)
1573 regs->flags |= X86_EFLAGS_TF;
1574
1575 #ifdef CONFIG_SECCOMP
1576 /*
1577 * Call seccomp_phase2 before running the other hooks so that
1578 * they can see any changes made by a seccomp tracer.
1579 */
1580 if (phase1_result > 1 && seccomp_phase2(phase1_result)) {
1581 /* seccomp failures shouldn't expose any additional code. */
1582 return -1;
1583 }
1584 #endif
1585
1586 if (unlikely(work & _TIF_SYSCALL_EMU))
1587 ret = -1L;
1588
1589 if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1590 tracehook_report_syscall_entry(regs))
1591 ret = -1L;
1592
1593 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1594 trace_sys_enter(regs, regs->orig_ax);
1595
1596 do_audit_syscall_entry(regs, arch);
1597
1598 return ret ?: regs->orig_ax;
1599 }
1600
syscall_trace_enter(struct pt_regs * regs)1601 long syscall_trace_enter(struct pt_regs *regs)
1602 {
1603 u32 arch = is_ia32_task() ? AUDIT_ARCH_I386 : AUDIT_ARCH_X86_64;
1604 unsigned long phase1_result = syscall_trace_enter_phase1(regs, arch);
1605
1606 if (phase1_result == 0)
1607 return regs->orig_ax;
1608 else
1609 return syscall_trace_enter_phase2(regs, arch, phase1_result);
1610 }
1611
syscall_trace_leave(struct pt_regs * regs)1612 void syscall_trace_leave(struct pt_regs *regs)
1613 {
1614 bool step;
1615
1616 /*
1617 * We may come here right after calling schedule_user()
1618 * or do_notify_resume(), in which case we can be in RCU
1619 * user mode.
1620 */
1621 user_exit();
1622
1623 audit_syscall_exit(regs);
1624
1625 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1626 trace_sys_exit(regs, regs->ax);
1627
1628 /*
1629 * If TIF_SYSCALL_EMU is set, we only get here because of
1630 * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1631 * We already reported this syscall instruction in
1632 * syscall_trace_enter().
1633 */
1634 step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1635 !test_thread_flag(TIF_SYSCALL_EMU);
1636 if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1637 tracehook_report_syscall_exit(regs, step);
1638
1639 user_enter();
1640 }
1641