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