Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc-2.6
[linux-2.6.git] / arch / x86 / kernel / ptrace.c
1 /* By Ross Biro 1/23/92 */
2 /*
3  * Pentium III FXSR, SSE support
4  *      Gareth Hughes <gareth@valinux.com>, May 2000
5  *
6  * BTS tracing
7  *      Markus Metzger <markus.t.metzger@intel.com>, Dec 2007
8  */
9
10 #include <linux/kernel.h>
11 #include <linux/sched.h>
12 #include <linux/mm.h>
13 #include <linux/smp.h>
14 #include <linux/errno.h>
15 #include <linux/ptrace.h>
16 #include <linux/regset.h>
17 #include <linux/tracehook.h>
18 #include <linux/user.h>
19 #include <linux/elf.h>
20 #include <linux/security.h>
21 #include <linux/audit.h>
22 #include <linux/seccomp.h>
23 #include <linux/signal.h>
24 #include <linux/workqueue.h>
25 #include <linux/perf_event.h>
26 #include <linux/hw_breakpoint.h>
27
28 #include <asm/uaccess.h>
29 #include <asm/pgtable.h>
30 #include <asm/system.h>
31 #include <asm/processor.h>
32 #include <asm/i387.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/ds.h>
39 #include <asm/hw_breakpoint.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  */
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  */
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  */
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 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
172 {
173         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
174         return &regs->bx + (regno >> 2);
175 }
176
177 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
178 {
179         /*
180          * Returning the value truncates it to 16 bits.
181          */
182         unsigned int retval;
183         if (offset != offsetof(struct user_regs_struct, gs))
184                 retval = *pt_regs_access(task_pt_regs(task), offset);
185         else {
186                 if (task == current)
187                         retval = get_user_gs(task_pt_regs(task));
188                 else
189                         retval = task_user_gs(task);
190         }
191         return retval;
192 }
193
194 static int set_segment_reg(struct task_struct *task,
195                            unsigned long offset, u16 value)
196 {
197         /*
198          * The value argument was already truncated to 16 bits.
199          */
200         if (invalid_selector(value))
201                 return -EIO;
202
203         /*
204          * For %cs and %ss we cannot permit a null selector.
205          * We can permit a bogus selector as long as it has USER_RPL.
206          * Null selectors are fine for other segment registers, but
207          * we will never get back to user mode with invalid %cs or %ss
208          * and will take the trap in iret instead.  Much code relies
209          * on user_mode() to distinguish a user trap frame (which can
210          * safely use invalid selectors) from a kernel trap frame.
211          */
212         switch (offset) {
213         case offsetof(struct user_regs_struct, cs):
214         case offsetof(struct user_regs_struct, ss):
215                 if (unlikely(value == 0))
216                         return -EIO;
217
218         default:
219                 *pt_regs_access(task_pt_regs(task), offset) = value;
220                 break;
221
222         case offsetof(struct user_regs_struct, gs):
223                 if (task == current)
224                         set_user_gs(task_pt_regs(task), value);
225                 else
226                         task_user_gs(task) = value;
227         }
228
229         return 0;
230 }
231
232 #else  /* CONFIG_X86_64 */
233
234 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
235
236 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
237 {
238         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
239         return &regs->r15 + (offset / sizeof(regs->r15));
240 }
241
242 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
243 {
244         /*
245          * Returning the value truncates it to 16 bits.
246          */
247         unsigned int seg;
248
249         switch (offset) {
250         case offsetof(struct user_regs_struct, fs):
251                 if (task == current) {
252                         /* Older gas can't assemble movq %?s,%r?? */
253                         asm("movl %%fs,%0" : "=r" (seg));
254                         return seg;
255                 }
256                 return task->thread.fsindex;
257         case offsetof(struct user_regs_struct, gs):
258                 if (task == current) {
259                         asm("movl %%gs,%0" : "=r" (seg));
260                         return seg;
261                 }
262                 return task->thread.gsindex;
263         case offsetof(struct user_regs_struct, ds):
264                 if (task == current) {
265                         asm("movl %%ds,%0" : "=r" (seg));
266                         return seg;
267                 }
268                 return task->thread.ds;
269         case offsetof(struct user_regs_struct, es):
270                 if (task == current) {
271                         asm("movl %%es,%0" : "=r" (seg));
272                         return seg;
273                 }
274                 return task->thread.es;
275
276         case offsetof(struct user_regs_struct, cs):
277         case offsetof(struct user_regs_struct, ss):
278                 break;
279         }
280         return *pt_regs_access(task_pt_regs(task), offset);
281 }
282
283 static int set_segment_reg(struct task_struct *task,
284                            unsigned long offset, u16 value)
285 {
286         /*
287          * The value argument was already truncated to 16 bits.
288          */
289         if (invalid_selector(value))
290                 return -EIO;
291
292         switch (offset) {
293         case offsetof(struct user_regs_struct,fs):
294                 /*
295                  * If this is setting fs as for normal 64-bit use but
296                  * setting fs_base has implicitly changed it, leave it.
297                  */
298                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
299                      task->thread.fs != 0) ||
300                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
301                      task->thread.fs == 0))
302                         break;
303                 task->thread.fsindex = value;
304                 if (task == current)
305                         loadsegment(fs, task->thread.fsindex);
306                 break;
307         case offsetof(struct user_regs_struct,gs):
308                 /*
309                  * If this is setting gs as for normal 64-bit use but
310                  * setting gs_base has implicitly changed it, leave it.
311                  */
312                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
313                      task->thread.gs != 0) ||
314                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
315                      task->thread.gs == 0))
316                         break;
317                 task->thread.gsindex = value;
318                 if (task == current)
319                         load_gs_index(task->thread.gsindex);
320                 break;
321         case offsetof(struct user_regs_struct,ds):
322                 task->thread.ds = value;
323                 if (task == current)
324                         loadsegment(ds, task->thread.ds);
325                 break;
326         case offsetof(struct user_regs_struct,es):
327                 task->thread.es = value;
328                 if (task == current)
329                         loadsegment(es, task->thread.es);
330                 break;
331
332                 /*
333                  * Can't actually change these in 64-bit mode.
334                  */
335         case offsetof(struct user_regs_struct,cs):
336                 if (unlikely(value == 0))
337                         return -EIO;
338 #ifdef CONFIG_IA32_EMULATION
339                 if (test_tsk_thread_flag(task, TIF_IA32))
340                         task_pt_regs(task)->cs = value;
341 #endif
342                 break;
343         case offsetof(struct user_regs_struct,ss):
344                 if (unlikely(value == 0))
345                         return -EIO;
346 #ifdef CONFIG_IA32_EMULATION
347                 if (test_tsk_thread_flag(task, TIF_IA32))
348                         task_pt_regs(task)->ss = value;
349 #endif
350                 break;
351         }
352
353         return 0;
354 }
355
356 #endif  /* CONFIG_X86_32 */
357
358 static unsigned long get_flags(struct task_struct *task)
359 {
360         unsigned long retval = task_pt_regs(task)->flags;
361
362         /*
363          * If the debugger set TF, hide it from the readout.
364          */
365         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
366                 retval &= ~X86_EFLAGS_TF;
367
368         return retval;
369 }
370
371 static int set_flags(struct task_struct *task, unsigned long value)
372 {
373         struct pt_regs *regs = task_pt_regs(task);
374
375         /*
376          * If the user value contains TF, mark that
377          * it was not "us" (the debugger) that set it.
378          * If not, make sure it stays set if we had.
379          */
380         if (value & X86_EFLAGS_TF)
381                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
382         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
383                 value |= X86_EFLAGS_TF;
384
385         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
386
387         return 0;
388 }
389
390 static int putreg(struct task_struct *child,
391                   unsigned long offset, unsigned long value)
392 {
393         switch (offset) {
394         case offsetof(struct user_regs_struct, cs):
395         case offsetof(struct user_regs_struct, ds):
396         case offsetof(struct user_regs_struct, es):
397         case offsetof(struct user_regs_struct, fs):
398         case offsetof(struct user_regs_struct, gs):
399         case offsetof(struct user_regs_struct, ss):
400                 return set_segment_reg(child, offset, value);
401
402         case offsetof(struct user_regs_struct, flags):
403                 return set_flags(child, value);
404
405 #ifdef CONFIG_X86_64
406         case offsetof(struct user_regs_struct,fs_base):
407                 if (value >= TASK_SIZE_OF(child))
408                         return -EIO;
409                 /*
410                  * When changing the segment base, use do_arch_prctl
411                  * to set either thread.fs or thread.fsindex and the
412                  * corresponding GDT slot.
413                  */
414                 if (child->thread.fs != value)
415                         return do_arch_prctl(child, ARCH_SET_FS, value);
416                 return 0;
417         case offsetof(struct user_regs_struct,gs_base):
418                 /*
419                  * Exactly the same here as the %fs handling above.
420                  */
421                 if (value >= TASK_SIZE_OF(child))
422                         return -EIO;
423                 if (child->thread.gs != value)
424                         return do_arch_prctl(child, ARCH_SET_GS, value);
425                 return 0;
426 #endif
427         }
428
429         *pt_regs_access(task_pt_regs(child), offset) = value;
430         return 0;
431 }
432
433 static unsigned long getreg(struct task_struct *task, unsigned long offset)
434 {
435         switch (offset) {
436         case offsetof(struct user_regs_struct, cs):
437         case offsetof(struct user_regs_struct, ds):
438         case offsetof(struct user_regs_struct, es):
439         case offsetof(struct user_regs_struct, fs):
440         case offsetof(struct user_regs_struct, gs):
441         case offsetof(struct user_regs_struct, ss):
442                 return get_segment_reg(task, offset);
443
444         case offsetof(struct user_regs_struct, flags):
445                 return get_flags(task);
446
447 #ifdef CONFIG_X86_64
448         case offsetof(struct user_regs_struct, fs_base): {
449                 /*
450                  * do_arch_prctl may have used a GDT slot instead of
451                  * the MSR.  To userland, it appears the same either
452                  * way, except the %fs segment selector might not be 0.
453                  */
454                 unsigned int seg = task->thread.fsindex;
455                 if (task->thread.fs != 0)
456                         return task->thread.fs;
457                 if (task == current)
458                         asm("movl %%fs,%0" : "=r" (seg));
459                 if (seg != FS_TLS_SEL)
460                         return 0;
461                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
462         }
463         case offsetof(struct user_regs_struct, gs_base): {
464                 /*
465                  * Exactly the same here as the %fs handling above.
466                  */
467                 unsigned int seg = task->thread.gsindex;
468                 if (task->thread.gs != 0)
469                         return task->thread.gs;
470                 if (task == current)
471                         asm("movl %%gs,%0" : "=r" (seg));
472                 if (seg != GS_TLS_SEL)
473                         return 0;
474                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
475         }
476 #endif
477         }
478
479         return *pt_regs_access(task_pt_regs(task), offset);
480 }
481
482 static int genregs_get(struct task_struct *target,
483                        const struct user_regset *regset,
484                        unsigned int pos, unsigned int count,
485                        void *kbuf, void __user *ubuf)
486 {
487         if (kbuf) {
488                 unsigned long *k = kbuf;
489                 while (count >= sizeof(*k)) {
490                         *k++ = getreg(target, pos);
491                         count -= sizeof(*k);
492                         pos += sizeof(*k);
493                 }
494         } else {
495                 unsigned long __user *u = ubuf;
496                 while (count >= sizeof(*u)) {
497                         if (__put_user(getreg(target, pos), u++))
498                                 return -EFAULT;
499                         count -= sizeof(*u);
500                         pos += sizeof(*u);
501                 }
502         }
503
504         return 0;
505 }
506
507 static int genregs_set(struct task_struct *target,
508                        const struct user_regset *regset,
509                        unsigned int pos, unsigned int count,
510                        const void *kbuf, const void __user *ubuf)
511 {
512         int ret = 0;
513         if (kbuf) {
514                 const unsigned long *k = kbuf;
515                 while (count >= sizeof(*k) && !ret) {
516                         ret = putreg(target, pos, *k++);
517                         count -= sizeof(*k);
518                         pos += sizeof(*k);
519                 }
520         } else {
521                 const unsigned long  __user *u = ubuf;
522                 while (count >= sizeof(*u) && !ret) {
523                         unsigned long word;
524                         ret = __get_user(word, u++);
525                         if (ret)
526                                 break;
527                         ret = putreg(target, pos, word);
528                         count -= sizeof(*u);
529                         pos += sizeof(*u);
530                 }
531         }
532         return ret;
533 }
534
535 static void ptrace_triggered(struct perf_event *bp, int nmi,
536                              struct perf_sample_data *data,
537                              struct pt_regs *regs)
538 {
539         int i;
540         struct thread_struct *thread = &(current->thread);
541
542         /*
543          * Store in the virtual DR6 register the fact that the breakpoint
544          * was hit so the thread's debugger will see it.
545          */
546         for (i = 0; i < HBP_NUM; i++) {
547                 if (thread->ptrace_bps[i] == bp)
548                         break;
549         }
550
551         thread->debugreg6 |= (DR_TRAP0 << i);
552 }
553
554 /*
555  * Walk through every ptrace breakpoints for this thread and
556  * build the dr7 value on top of their attributes.
557  *
558  */
559 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
560 {
561         int i;
562         int dr7 = 0;
563         struct arch_hw_breakpoint *info;
564
565         for (i = 0; i < HBP_NUM; i++) {
566                 if (bp[i] && !bp[i]->attr.disabled) {
567                         info = counter_arch_bp(bp[i]);
568                         dr7 |= encode_dr7(i, info->len, info->type);
569                 }
570         }
571
572         return dr7;
573 }
574
575 static int
576 ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
577                          struct task_struct *tsk, int disabled)
578 {
579         int err;
580         int gen_len, gen_type;
581         struct perf_event_attr attr;
582
583         /*
584          * We should have at least an inactive breakpoint at this
585          * slot. It means the user is writing dr7 without having
586          * written the address register first
587          */
588         if (!bp)
589                 return -EINVAL;
590
591         err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
592         if (err)
593                 return err;
594
595         attr = bp->attr;
596         attr.bp_len = gen_len;
597         attr.bp_type = gen_type;
598         attr.disabled = disabled;
599
600         return modify_user_hw_breakpoint(bp, &attr);
601 }
602
603 /*
604  * Handle ptrace writes to debug register 7.
605  */
606 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
607 {
608         struct thread_struct *thread = &(tsk->thread);
609         unsigned long old_dr7;
610         int i, orig_ret = 0, rc = 0;
611         int enabled, second_pass = 0;
612         unsigned len, type;
613         struct perf_event *bp;
614
615         data &= ~DR_CONTROL_RESERVED;
616         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
617 restore:
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         return ((orig_ret < 0) ? orig_ret : rc);
663 }
664
665 /*
666  * Handle PTRACE_PEEKUSR calls for the debug register area.
667  */
668 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
669 {
670         struct thread_struct *thread = &(tsk->thread);
671         unsigned long val = 0;
672
673         if (n < HBP_NUM) {
674                 struct perf_event *bp;
675                 bp = thread->ptrace_bps[n];
676                 if (!bp)
677                         return 0;
678                 val = bp->hw.info.address;
679         } else if (n == 6) {
680                 val = thread->debugreg6;
681          } else if (n == 7) {
682                 val = thread->ptrace_dr7;
683         }
684         return val;
685 }
686
687 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
688                                       unsigned long addr)
689 {
690         struct perf_event *bp;
691         struct thread_struct *t = &tsk->thread;
692         struct perf_event_attr attr;
693
694         if (!t->ptrace_bps[nr]) {
695                 hw_breakpoint_init(&attr);
696                 /*
697                  * Put stub len and type to register (reserve) an inactive but
698                  * correct bp
699                  */
700                 attr.bp_addr = addr;
701                 attr.bp_len = HW_BREAKPOINT_LEN_1;
702                 attr.bp_type = HW_BREAKPOINT_W;
703                 attr.disabled = 1;
704
705                 bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
706
707                 /*
708                  * CHECKME: the previous code returned -EIO if the addr wasn't
709                  * a valid task virtual addr. The new one will return -EINVAL in
710                  *  this case.
711                  * -EINVAL may be what we want for in-kernel breakpoints users,
712                  * but -EIO looks better for ptrace, since we refuse a register
713                  * writing for the user. And anyway this is the previous
714                  * behaviour.
715                  */
716                 if (IS_ERR(bp))
717                         return PTR_ERR(bp);
718
719                 t->ptrace_bps[nr] = bp;
720         } else {
721                 int err;
722
723                 bp = t->ptrace_bps[nr];
724
725                 attr = bp->attr;
726                 attr.bp_addr = addr;
727                 err = modify_user_hw_breakpoint(bp, &attr);
728                 if (err)
729                         return err;
730         }
731
732
733         return 0;
734 }
735
736 /*
737  * Handle PTRACE_POKEUSR calls for the debug register area.
738  */
739 int ptrace_set_debugreg(struct task_struct *tsk, int n, unsigned long val)
740 {
741         struct thread_struct *thread = &(tsk->thread);
742         int rc = 0;
743
744         /* There are no DR4 or DR5 registers */
745         if (n == 4 || n == 5)
746                 return -EIO;
747
748         if (n == 6) {
749                 thread->debugreg6 = val;
750                 goto ret_path;
751         }
752         if (n < HBP_NUM) {
753                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
754                 if (rc)
755                         return rc;
756         }
757         /* All that's left is DR7 */
758         if (n == 7) {
759                 rc = ptrace_write_dr7(tsk, val);
760                 if (!rc)
761                         thread->ptrace_dr7 = val;
762         }
763
764 ret_path:
765         return rc;
766 }
767
768 /*
769  * These access the current or another (stopped) task's io permission
770  * bitmap for debugging or core dump.
771  */
772 static int ioperm_active(struct task_struct *target,
773                          const struct user_regset *regset)
774 {
775         return target->thread.io_bitmap_max / regset->size;
776 }
777
778 static int ioperm_get(struct task_struct *target,
779                       const struct user_regset *regset,
780                       unsigned int pos, unsigned int count,
781                       void *kbuf, void __user *ubuf)
782 {
783         if (!target->thread.io_bitmap_ptr)
784                 return -ENXIO;
785
786         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
787                                    target->thread.io_bitmap_ptr,
788                                    0, IO_BITMAP_BYTES);
789 }
790
791 #ifdef CONFIG_X86_PTRACE_BTS
792 /*
793  * A branch trace store context.
794  *
795  * Contexts may only be installed by ptrace_bts_config() and only for
796  * ptraced tasks.
797  *
798  * Contexts are destroyed when the tracee is detached from the tracer.
799  * The actual destruction work requires interrupts enabled, so the
800  * work is deferred and will be scheduled during __ptrace_unlink().
801  *
802  * Contexts hold an additional task_struct reference on the traced
803  * task, as well as a reference on the tracer's mm.
804  *
805  * Ptrace already holds a task_struct for the duration of ptrace operations,
806  * but since destruction is deferred, it may be executed after both
807  * tracer and tracee exited.
808  */
809 struct bts_context {
810         /* The branch trace handle. */
811         struct bts_tracer       *tracer;
812
813         /* The buffer used to store the branch trace and its size. */
814         void                    *buffer;
815         unsigned int            size;
816
817         /* The mm that paid for the above buffer. */
818         struct mm_struct        *mm;
819
820         /* The task this context belongs to. */
821         struct task_struct      *task;
822
823         /* The signal to send on a bts buffer overflow. */
824         unsigned int            bts_ovfl_signal;
825
826         /* The work struct to destroy a context. */
827         struct work_struct      work;
828 };
829
830 static int alloc_bts_buffer(struct bts_context *context, unsigned int size)
831 {
832         void *buffer = NULL;
833         int err = -ENOMEM;
834
835         err = account_locked_memory(current->mm, current->signal->rlim, size);
836         if (err < 0)
837                 return err;
838
839         buffer = kzalloc(size, GFP_KERNEL);
840         if (!buffer)
841                 goto out_refund;
842
843         context->buffer = buffer;
844         context->size = size;
845         context->mm = get_task_mm(current);
846
847         return 0;
848
849  out_refund:
850         refund_locked_memory(current->mm, size);
851         return err;
852 }
853
854 static inline void free_bts_buffer(struct bts_context *context)
855 {
856         if (!context->buffer)
857                 return;
858
859         kfree(context->buffer);
860         context->buffer = NULL;
861
862         refund_locked_memory(context->mm, context->size);
863         context->size = 0;
864
865         mmput(context->mm);
866         context->mm = NULL;
867 }
868
869 static void free_bts_context_work(struct work_struct *w)
870 {
871         struct bts_context *context;
872
873         context = container_of(w, struct bts_context, work);
874
875         ds_release_bts(context->tracer);
876         put_task_struct(context->task);
877         free_bts_buffer(context);
878         kfree(context);
879 }
880
881 static inline void free_bts_context(struct bts_context *context)
882 {
883         INIT_WORK(&context->work, free_bts_context_work);
884         schedule_work(&context->work);
885 }
886
887 static inline struct bts_context *alloc_bts_context(struct task_struct *task)
888 {
889         struct bts_context *context = kzalloc(sizeof(*context), GFP_KERNEL);
890         if (context) {
891                 context->task = task;
892                 task->bts = context;
893
894                 get_task_struct(task);
895         }
896
897         return context;
898 }
899
900 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
901                                   struct bts_struct __user *out)
902 {
903         struct bts_context *context;
904         const struct bts_trace *trace;
905         struct bts_struct bts;
906         const unsigned char *at;
907         int error;
908
909         context = child->bts;
910         if (!context)
911                 return -ESRCH;
912
913         trace = ds_read_bts(context->tracer);
914         if (!trace)
915                 return -ESRCH;
916
917         at = trace->ds.top - ((index + 1) * trace->ds.size);
918         if ((void *)at < trace->ds.begin)
919                 at += (trace->ds.n * trace->ds.size);
920
921         if (!trace->read)
922                 return -EOPNOTSUPP;
923
924         error = trace->read(context->tracer, at, &bts);
925         if (error < 0)
926                 return error;
927
928         if (copy_to_user(out, &bts, sizeof(bts)))
929                 return -EFAULT;
930
931         return sizeof(bts);
932 }
933
934 static int ptrace_bts_drain(struct task_struct *child,
935                             long size,
936                             struct bts_struct __user *out)
937 {
938         struct bts_context *context;
939         const struct bts_trace *trace;
940         const unsigned char *at;
941         int error, drained = 0;
942
943         context = child->bts;
944         if (!context)
945                 return -ESRCH;
946
947         trace = ds_read_bts(context->tracer);
948         if (!trace)
949                 return -ESRCH;
950
951         if (!trace->read)
952                 return -EOPNOTSUPP;
953
954         if (size < (trace->ds.top - trace->ds.begin))
955                 return -EIO;
956
957         for (at = trace->ds.begin; (void *)at < trace->ds.top;
958              out++, drained++, at += trace->ds.size) {
959                 struct bts_struct bts;
960
961                 error = trace->read(context->tracer, at, &bts);
962                 if (error < 0)
963                         return error;
964
965                 if (copy_to_user(out, &bts, sizeof(bts)))
966                         return -EFAULT;
967         }
968
969         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
970
971         error = ds_reset_bts(context->tracer);
972         if (error < 0)
973                 return error;
974
975         return drained;
976 }
977
978 static int ptrace_bts_config(struct task_struct *child,
979                              long cfg_size,
980                              const struct ptrace_bts_config __user *ucfg)
981 {
982         struct bts_context *context;
983         struct ptrace_bts_config cfg;
984         unsigned int flags = 0;
985
986         if (cfg_size < sizeof(cfg))
987                 return -EIO;
988
989         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
990                 return -EFAULT;
991
992         context = child->bts;
993         if (!context)
994                 context = alloc_bts_context(child);
995         if (!context)
996                 return -ENOMEM;
997
998         if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
999                 if (!cfg.signal)
1000                         return -EINVAL;
1001
1002                 return -EOPNOTSUPP;
1003                 context->bts_ovfl_signal = cfg.signal;
1004         }
1005
1006         ds_release_bts(context->tracer);
1007         context->tracer = NULL;
1008
1009         if ((cfg.flags & PTRACE_BTS_O_ALLOC) && (cfg.size != context->size)) {
1010                 int err;
1011
1012                 free_bts_buffer(context);
1013                 if (!cfg.size)
1014                         return 0;
1015
1016                 err = alloc_bts_buffer(context, cfg.size);
1017                 if (err < 0)
1018                         return err;
1019         }
1020
1021         if (cfg.flags & PTRACE_BTS_O_TRACE)
1022                 flags |= BTS_USER;
1023
1024         if (cfg.flags & PTRACE_BTS_O_SCHED)
1025                 flags |= BTS_TIMESTAMPS;
1026
1027         context->tracer =
1028                 ds_request_bts_task(child, context->buffer, context->size,
1029                                     NULL, (size_t)-1, flags);
1030         if (unlikely(IS_ERR(context->tracer))) {
1031                 int error = PTR_ERR(context->tracer);
1032
1033                 free_bts_buffer(context);
1034                 context->tracer = NULL;
1035                 return error;
1036         }
1037
1038         return sizeof(cfg);
1039 }
1040
1041 static int ptrace_bts_status(struct task_struct *child,
1042                              long cfg_size,
1043                              struct ptrace_bts_config __user *ucfg)
1044 {
1045         struct bts_context *context;
1046         const struct bts_trace *trace;
1047         struct ptrace_bts_config cfg;
1048
1049         context = child->bts;
1050         if (!context)
1051                 return -ESRCH;
1052
1053         if (cfg_size < sizeof(cfg))
1054                 return -EIO;
1055
1056         trace = ds_read_bts(context->tracer);
1057         if (!trace)
1058                 return -ESRCH;
1059
1060         memset(&cfg, 0, sizeof(cfg));
1061         cfg.size        = trace->ds.end - trace->ds.begin;
1062         cfg.signal      = context->bts_ovfl_signal;
1063         cfg.bts_size    = sizeof(struct bts_struct);
1064
1065         if (cfg.signal)
1066                 cfg.flags |= PTRACE_BTS_O_SIGNAL;
1067
1068         if (trace->ds.flags & BTS_USER)
1069                 cfg.flags |= PTRACE_BTS_O_TRACE;
1070
1071         if (trace->ds.flags & BTS_TIMESTAMPS)
1072                 cfg.flags |= PTRACE_BTS_O_SCHED;
1073
1074         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
1075                 return -EFAULT;
1076
1077         return sizeof(cfg);
1078 }
1079
1080 static int ptrace_bts_clear(struct task_struct *child)
1081 {
1082         struct bts_context *context;
1083         const struct bts_trace *trace;
1084
1085         context = child->bts;
1086         if (!context)
1087                 return -ESRCH;
1088
1089         trace = ds_read_bts(context->tracer);
1090         if (!trace)
1091                 return -ESRCH;
1092
1093         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
1094
1095         return ds_reset_bts(context->tracer);
1096 }
1097
1098 static int ptrace_bts_size(struct task_struct *child)
1099 {
1100         struct bts_context *context;
1101         const struct bts_trace *trace;
1102
1103         context = child->bts;
1104         if (!context)
1105                 return -ESRCH;
1106
1107         trace = ds_read_bts(context->tracer);
1108         if (!trace)
1109                 return -ESRCH;
1110
1111         return (trace->ds.top - trace->ds.begin) / trace->ds.size;
1112 }
1113
1114 /*
1115  * Called from __ptrace_unlink() after the child has been moved back
1116  * to its original parent.
1117  */
1118 void ptrace_bts_untrace(struct task_struct *child)
1119 {
1120         if (unlikely(child->bts)) {
1121                 free_bts_context(child->bts);
1122                 child->bts = NULL;
1123         }
1124 }
1125 #endif /* CONFIG_X86_PTRACE_BTS */
1126
1127 /*
1128  * Called by kernel/ptrace.c when detaching..
1129  *
1130  * Make sure the single step bit is not set.
1131  */
1132 void ptrace_disable(struct task_struct *child)
1133 {
1134         user_disable_single_step(child);
1135 #ifdef TIF_SYSCALL_EMU
1136         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
1137 #endif
1138 }
1139
1140 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1141 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
1142 #endif
1143
1144 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
1145 {
1146         int ret;
1147         unsigned long __user *datap = (unsigned long __user *)data;
1148
1149         switch (request) {
1150         /* read the word at location addr in the USER area. */
1151         case PTRACE_PEEKUSR: {
1152                 unsigned long tmp;
1153
1154                 ret = -EIO;
1155                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
1156                     addr >= sizeof(struct user))
1157                         break;
1158
1159                 tmp = 0;  /* Default return condition */
1160                 if (addr < sizeof(struct user_regs_struct))
1161                         tmp = getreg(child, addr);
1162                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1163                          addr <= offsetof(struct user, u_debugreg[7])) {
1164                         addr -= offsetof(struct user, u_debugreg[0]);
1165                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1166                 }
1167                 ret = put_user(tmp, datap);
1168                 break;
1169         }
1170
1171         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
1172                 ret = -EIO;
1173                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
1174                     addr >= sizeof(struct user))
1175                         break;
1176
1177                 if (addr < sizeof(struct user_regs_struct))
1178                         ret = putreg(child, addr, data);
1179                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1180                          addr <= offsetof(struct user, u_debugreg[7])) {
1181                         addr -= offsetof(struct user, u_debugreg[0]);
1182                         ret = ptrace_set_debugreg(child,
1183                                                   addr / sizeof(data), data);
1184                 }
1185                 break;
1186
1187         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1188                 return copy_regset_to_user(child,
1189                                            task_user_regset_view(current),
1190                                            REGSET_GENERAL,
1191                                            0, sizeof(struct user_regs_struct),
1192                                            datap);
1193
1194         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1195                 return copy_regset_from_user(child,
1196                                              task_user_regset_view(current),
1197                                              REGSET_GENERAL,
1198                                              0, sizeof(struct user_regs_struct),
1199                                              datap);
1200
1201         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1202                 return copy_regset_to_user(child,
1203                                            task_user_regset_view(current),
1204                                            REGSET_FP,
1205                                            0, sizeof(struct user_i387_struct),
1206                                            datap);
1207
1208         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1209                 return copy_regset_from_user(child,
1210                                              task_user_regset_view(current),
1211                                              REGSET_FP,
1212                                              0, sizeof(struct user_i387_struct),
1213                                              datap);
1214
1215 #ifdef CONFIG_X86_32
1216         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1217                 return copy_regset_to_user(child, &user_x86_32_view,
1218                                            REGSET_XFP,
1219                                            0, sizeof(struct user_fxsr_struct),
1220                                            datap) ? -EIO : 0;
1221
1222         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1223                 return copy_regset_from_user(child, &user_x86_32_view,
1224                                              REGSET_XFP,
1225                                              0, sizeof(struct user_fxsr_struct),
1226                                              datap) ? -EIO : 0;
1227 #endif
1228
1229 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1230         case PTRACE_GET_THREAD_AREA:
1231                 if (addr < 0)
1232                         return -EIO;
1233                 ret = do_get_thread_area(child, addr,
1234                                          (struct user_desc __user *) data);
1235                 break;
1236
1237         case PTRACE_SET_THREAD_AREA:
1238                 if (addr < 0)
1239                         return -EIO;
1240                 ret = do_set_thread_area(child, addr,
1241                                          (struct user_desc __user *) data, 0);
1242                 break;
1243 #endif
1244
1245 #ifdef CONFIG_X86_64
1246                 /* normal 64bit interface to access TLS data.
1247                    Works just like arch_prctl, except that the arguments
1248                    are reversed. */
1249         case PTRACE_ARCH_PRCTL:
1250                 ret = do_arch_prctl(child, data, addr);
1251                 break;
1252 #endif
1253
1254         /*
1255          * These bits need more cooking - not enabled yet:
1256          */
1257 #ifdef CONFIG_X86_PTRACE_BTS
1258         case PTRACE_BTS_CONFIG:
1259                 ret = ptrace_bts_config
1260                         (child, data, (struct ptrace_bts_config __user *)addr);
1261                 break;
1262
1263         case PTRACE_BTS_STATUS:
1264                 ret = ptrace_bts_status
1265                         (child, data, (struct ptrace_bts_config __user *)addr);
1266                 break;
1267
1268         case PTRACE_BTS_SIZE:
1269                 ret = ptrace_bts_size(child);
1270                 break;
1271
1272         case PTRACE_BTS_GET:
1273                 ret = ptrace_bts_read_record
1274                         (child, data, (struct bts_struct __user *) addr);
1275                 break;
1276
1277         case PTRACE_BTS_CLEAR:
1278                 ret = ptrace_bts_clear(child);
1279                 break;
1280
1281         case PTRACE_BTS_DRAIN:
1282                 ret = ptrace_bts_drain
1283                         (child, data, (struct bts_struct __user *) addr);
1284                 break;
1285 #endif /* CONFIG_X86_PTRACE_BTS */
1286
1287         default:
1288                 ret = ptrace_request(child, request, addr, data);
1289                 break;
1290         }
1291
1292         return ret;
1293 }
1294
1295 #ifdef CONFIG_IA32_EMULATION
1296
1297 #include <linux/compat.h>
1298 #include <linux/syscalls.h>
1299 #include <asm/ia32.h>
1300 #include <asm/user32.h>
1301
1302 #define R32(l,q)                                                        \
1303         case offsetof(struct user32, regs.l):                           \
1304                 regs->q = value; break
1305
1306 #define SEG32(rs)                                                       \
1307         case offsetof(struct user32, regs.rs):                          \
1308                 return set_segment_reg(child,                           \
1309                                        offsetof(struct user_regs_struct, rs), \
1310                                        value);                          \
1311                 break
1312
1313 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
1314 {
1315         struct pt_regs *regs = task_pt_regs(child);
1316
1317         switch (regno) {
1318
1319         SEG32(cs);
1320         SEG32(ds);
1321         SEG32(es);
1322         SEG32(fs);
1323         SEG32(gs);
1324         SEG32(ss);
1325
1326         R32(ebx, bx);
1327         R32(ecx, cx);
1328         R32(edx, dx);
1329         R32(edi, di);
1330         R32(esi, si);
1331         R32(ebp, bp);
1332         R32(eax, ax);
1333         R32(eip, ip);
1334         R32(esp, sp);
1335
1336         case offsetof(struct user32, regs.orig_eax):
1337                 /*
1338                  * A 32-bit debugger setting orig_eax means to restore
1339                  * the state of the task restarting a 32-bit syscall.
1340                  * Make sure we interpret the -ERESTART* codes correctly
1341                  * in case the task is not actually still sitting at the
1342                  * exit from a 32-bit syscall with TS_COMPAT still set.
1343                  */
1344                 regs->orig_ax = value;
1345                 if (syscall_get_nr(child, regs) >= 0)
1346                         task_thread_info(child)->status |= TS_COMPAT;
1347                 break;
1348
1349         case offsetof(struct user32, regs.eflags):
1350                 return set_flags(child, value);
1351
1352         case offsetof(struct user32, u_debugreg[0]) ...
1353                 offsetof(struct user32, u_debugreg[7]):
1354                 regno -= offsetof(struct user32, u_debugreg[0]);
1355                 return ptrace_set_debugreg(child, regno / 4, value);
1356
1357         default:
1358                 if (regno > sizeof(struct user32) || (regno & 3))
1359                         return -EIO;
1360
1361                 /*
1362                  * Other dummy fields in the virtual user structure
1363                  * are ignored
1364                  */
1365                 break;
1366         }
1367         return 0;
1368 }
1369
1370 #undef R32
1371 #undef SEG32
1372
1373 #define R32(l,q)                                                        \
1374         case offsetof(struct user32, regs.l):                           \
1375                 *val = regs->q; break
1376
1377 #define SEG32(rs)                                                       \
1378         case offsetof(struct user32, regs.rs):                          \
1379                 *val = get_segment_reg(child,                           \
1380                                        offsetof(struct user_regs_struct, rs)); \
1381                 break
1382
1383 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1384 {
1385         struct pt_regs *regs = task_pt_regs(child);
1386
1387         switch (regno) {
1388
1389         SEG32(ds);
1390         SEG32(es);
1391         SEG32(fs);
1392         SEG32(gs);
1393
1394         R32(cs, cs);
1395         R32(ss, ss);
1396         R32(ebx, bx);
1397         R32(ecx, cx);
1398         R32(edx, dx);
1399         R32(edi, di);
1400         R32(esi, si);
1401         R32(ebp, bp);
1402         R32(eax, ax);
1403         R32(orig_eax, orig_ax);
1404         R32(eip, ip);
1405         R32(esp, sp);
1406
1407         case offsetof(struct user32, regs.eflags):
1408                 *val = get_flags(child);
1409                 break;
1410
1411         case offsetof(struct user32, u_debugreg[0]) ...
1412                 offsetof(struct user32, u_debugreg[7]):
1413                 regno -= offsetof(struct user32, u_debugreg[0]);
1414                 *val = ptrace_get_debugreg(child, regno / 4);
1415                 break;
1416
1417         default:
1418                 if (regno > sizeof(struct user32) || (regno & 3))
1419                         return -EIO;
1420
1421                 /*
1422                  * Other dummy fields in the virtual user structure
1423                  * are ignored
1424                  */
1425                 *val = 0;
1426                 break;
1427         }
1428         return 0;
1429 }
1430
1431 #undef R32
1432 #undef SEG32
1433
1434 static int genregs32_get(struct task_struct *target,
1435                          const struct user_regset *regset,
1436                          unsigned int pos, unsigned int count,
1437                          void *kbuf, void __user *ubuf)
1438 {
1439         if (kbuf) {
1440                 compat_ulong_t *k = kbuf;
1441                 while (count >= sizeof(*k)) {
1442                         getreg32(target, pos, k++);
1443                         count -= sizeof(*k);
1444                         pos += sizeof(*k);
1445                 }
1446         } else {
1447                 compat_ulong_t __user *u = ubuf;
1448                 while (count >= sizeof(*u)) {
1449                         compat_ulong_t word;
1450                         getreg32(target, pos, &word);
1451                         if (__put_user(word, u++))
1452                                 return -EFAULT;
1453                         count -= sizeof(*u);
1454                         pos += sizeof(*u);
1455                 }
1456         }
1457
1458         return 0;
1459 }
1460
1461 static int genregs32_set(struct task_struct *target,
1462                          const struct user_regset *regset,
1463                          unsigned int pos, unsigned int count,
1464                          const void *kbuf, const void __user *ubuf)
1465 {
1466         int ret = 0;
1467         if (kbuf) {
1468                 const compat_ulong_t *k = kbuf;
1469                 while (count >= sizeof(*k) && !ret) {
1470                         ret = putreg32(target, pos, *k++);
1471                         count -= sizeof(*k);
1472                         pos += sizeof(*k);
1473                 }
1474         } else {
1475                 const compat_ulong_t __user *u = ubuf;
1476                 while (count >= sizeof(*u) && !ret) {
1477                         compat_ulong_t word;
1478                         ret = __get_user(word, u++);
1479                         if (ret)
1480                                 break;
1481                         ret = putreg32(target, pos, word);
1482                         count -= sizeof(*u);
1483                         pos += sizeof(*u);
1484                 }
1485         }
1486         return ret;
1487 }
1488
1489 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1490                         compat_ulong_t caddr, compat_ulong_t cdata)
1491 {
1492         unsigned long addr = caddr;
1493         unsigned long data = cdata;
1494         void __user *datap = compat_ptr(data);
1495         int ret;
1496         __u32 val;
1497
1498         switch (request) {
1499         case PTRACE_PEEKUSR:
1500                 ret = getreg32(child, addr, &val);
1501                 if (ret == 0)
1502                         ret = put_user(val, (__u32 __user *)datap);
1503                 break;
1504
1505         case PTRACE_POKEUSR:
1506                 ret = putreg32(child, addr, data);
1507                 break;
1508
1509         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1510                 return copy_regset_to_user(child, &user_x86_32_view,
1511                                            REGSET_GENERAL,
1512                                            0, sizeof(struct user_regs_struct32),
1513                                            datap);
1514
1515         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1516                 return copy_regset_from_user(child, &user_x86_32_view,
1517                                              REGSET_GENERAL, 0,
1518                                              sizeof(struct user_regs_struct32),
1519                                              datap);
1520
1521         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1522                 return copy_regset_to_user(child, &user_x86_32_view,
1523                                            REGSET_FP, 0,
1524                                            sizeof(struct user_i387_ia32_struct),
1525                                            datap);
1526
1527         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1528                 return copy_regset_from_user(
1529                         child, &user_x86_32_view, REGSET_FP,
1530                         0, sizeof(struct user_i387_ia32_struct), datap);
1531
1532         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1533                 return copy_regset_to_user(child, &user_x86_32_view,
1534                                            REGSET_XFP, 0,
1535                                            sizeof(struct user32_fxsr_struct),
1536                                            datap);
1537
1538         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1539                 return copy_regset_from_user(child, &user_x86_32_view,
1540                                              REGSET_XFP, 0,
1541                                              sizeof(struct user32_fxsr_struct),
1542                                              datap);
1543
1544         case PTRACE_GET_THREAD_AREA:
1545         case PTRACE_SET_THREAD_AREA:
1546 #ifdef CONFIG_X86_PTRACE_BTS
1547         case PTRACE_BTS_CONFIG:
1548         case PTRACE_BTS_STATUS:
1549         case PTRACE_BTS_SIZE:
1550         case PTRACE_BTS_GET:
1551         case PTRACE_BTS_CLEAR:
1552         case PTRACE_BTS_DRAIN:
1553 #endif /* CONFIG_X86_PTRACE_BTS */
1554                 return arch_ptrace(child, request, addr, data);
1555
1556         default:
1557                 return compat_ptrace_request(child, request, addr, data);
1558         }
1559
1560         return ret;
1561 }
1562
1563 #endif  /* CONFIG_IA32_EMULATION */
1564
1565 #ifdef CONFIG_X86_64
1566
1567 static struct user_regset x86_64_regsets[] __read_mostly = {
1568         [REGSET_GENERAL] = {
1569                 .core_note_type = NT_PRSTATUS,
1570                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1571                 .size = sizeof(long), .align = sizeof(long),
1572                 .get = genregs_get, .set = genregs_set
1573         },
1574         [REGSET_FP] = {
1575                 .core_note_type = NT_PRFPREG,
1576                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1577                 .size = sizeof(long), .align = sizeof(long),
1578                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1579         },
1580         [REGSET_XSTATE] = {
1581                 .core_note_type = NT_X86_XSTATE,
1582                 .size = sizeof(u64), .align = sizeof(u64),
1583                 .active = xstateregs_active, .get = xstateregs_get,
1584                 .set = xstateregs_set
1585         },
1586         [REGSET_IOPERM64] = {
1587                 .core_note_type = NT_386_IOPERM,
1588                 .n = IO_BITMAP_LONGS,
1589                 .size = sizeof(long), .align = sizeof(long),
1590                 .active = ioperm_active, .get = ioperm_get
1591         },
1592 };
1593
1594 static const struct user_regset_view user_x86_64_view = {
1595         .name = "x86_64", .e_machine = EM_X86_64,
1596         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1597 };
1598
1599 #else  /* CONFIG_X86_32 */
1600
1601 #define user_regs_struct32      user_regs_struct
1602 #define genregs32_get           genregs_get
1603 #define genregs32_set           genregs_set
1604
1605 #define user_i387_ia32_struct   user_i387_struct
1606 #define user32_fxsr_struct      user_fxsr_struct
1607
1608 #endif  /* CONFIG_X86_64 */
1609
1610 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1611 static struct user_regset x86_32_regsets[] __read_mostly = {
1612         [REGSET_GENERAL] = {
1613                 .core_note_type = NT_PRSTATUS,
1614                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1615                 .size = sizeof(u32), .align = sizeof(u32),
1616                 .get = genregs32_get, .set = genregs32_set
1617         },
1618         [REGSET_FP] = {
1619                 .core_note_type = NT_PRFPREG,
1620                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1621                 .size = sizeof(u32), .align = sizeof(u32),
1622                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1623         },
1624         [REGSET_XFP] = {
1625                 .core_note_type = NT_PRXFPREG,
1626                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1627                 .size = sizeof(u32), .align = sizeof(u32),
1628                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1629         },
1630         [REGSET_XSTATE] = {
1631                 .core_note_type = NT_X86_XSTATE,
1632                 .size = sizeof(u64), .align = sizeof(u64),
1633                 .active = xstateregs_active, .get = xstateregs_get,
1634                 .set = xstateregs_set
1635         },
1636         [REGSET_TLS] = {
1637                 .core_note_type = NT_386_TLS,
1638                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1639                 .size = sizeof(struct user_desc),
1640                 .align = sizeof(struct user_desc),
1641                 .active = regset_tls_active,
1642                 .get = regset_tls_get, .set = regset_tls_set
1643         },
1644         [REGSET_IOPERM32] = {
1645                 .core_note_type = NT_386_IOPERM,
1646                 .n = IO_BITMAP_BYTES / sizeof(u32),
1647                 .size = sizeof(u32), .align = sizeof(u32),
1648                 .active = ioperm_active, .get = ioperm_get
1649         },
1650 };
1651
1652 static const struct user_regset_view user_x86_32_view = {
1653         .name = "i386", .e_machine = EM_386,
1654         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1655 };
1656 #endif
1657
1658 /*
1659  * This represents bytes 464..511 in the memory layout exported through
1660  * the REGSET_XSTATE interface.
1661  */
1662 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1663
1664 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1665 {
1666 #ifdef CONFIG_X86_64
1667         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1668 #endif
1669 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1670         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1671 #endif
1672         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1673 }
1674
1675 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1676 {
1677 #ifdef CONFIG_IA32_EMULATION
1678         if (test_tsk_thread_flag(task, TIF_IA32))
1679 #endif
1680 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1681                 return &user_x86_32_view;
1682 #endif
1683 #ifdef CONFIG_X86_64
1684         return &user_x86_64_view;
1685 #endif
1686 }
1687
1688 static void fill_sigtrap_info(struct task_struct *tsk,
1689                                 struct pt_regs *regs,
1690                                 int error_code, int si_code,
1691                                 struct siginfo *info)
1692 {
1693         tsk->thread.trap_no = 1;
1694         tsk->thread.error_code = error_code;
1695
1696         memset(info, 0, sizeof(*info));
1697         info->si_signo = SIGTRAP;
1698         info->si_code = si_code;
1699         info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1700 }
1701
1702 void user_single_step_siginfo(struct task_struct *tsk,
1703                                 struct pt_regs *regs,
1704                                 struct siginfo *info)
1705 {
1706         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1707 }
1708
1709 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1710                                          int error_code, int si_code)
1711 {
1712         struct siginfo info;
1713
1714         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1715         /* Send us the fake SIGTRAP */
1716         force_sig_info(SIGTRAP, &info, tsk);
1717 }
1718
1719
1720 #ifdef CONFIG_X86_32
1721 # define IS_IA32        1
1722 #elif defined CONFIG_IA32_EMULATION
1723 # define IS_IA32        is_compat_task()
1724 #else
1725 # define IS_IA32        0
1726 #endif
1727
1728 /*
1729  * We must return the syscall number to actually look up in the table.
1730  * This can be -1L to skip running any syscall at all.
1731  */
1732 asmregparm long syscall_trace_enter(struct pt_regs *regs)
1733 {
1734         long ret = 0;
1735
1736         /*
1737          * If we stepped into a sysenter/syscall insn, it trapped in
1738          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1739          * If user-mode had set TF itself, then it's still clear from
1740          * do_debug() and we need to set it again to restore the user
1741          * state.  If we entered on the slow path, TF was already set.
1742          */
1743         if (test_thread_flag(TIF_SINGLESTEP))
1744                 regs->flags |= X86_EFLAGS_TF;
1745
1746         /* do the secure computing check first */
1747         secure_computing(regs->orig_ax);
1748
1749         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1750                 ret = -1L;
1751
1752         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1753             tracehook_report_syscall_entry(regs))
1754                 ret = -1L;
1755
1756         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1757                 trace_sys_enter(regs, regs->orig_ax);
1758
1759         if (unlikely(current->audit_context)) {
1760                 if (IS_IA32)
1761                         audit_syscall_entry(AUDIT_ARCH_I386,
1762                                             regs->orig_ax,
1763                                             regs->bx, regs->cx,
1764                                             regs->dx, regs->si);
1765 #ifdef CONFIG_X86_64
1766                 else
1767                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1768                                             regs->orig_ax,
1769                                             regs->di, regs->si,
1770                                             regs->dx, regs->r10);
1771 #endif
1772         }
1773
1774         return ret ?: regs->orig_ax;
1775 }
1776
1777 asmregparm void syscall_trace_leave(struct pt_regs *regs)
1778 {
1779         bool step;
1780
1781         if (unlikely(current->audit_context))
1782                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1783
1784         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1785                 trace_sys_exit(regs, regs->ax);
1786
1787         /*
1788          * If TIF_SYSCALL_EMU is set, we only get here because of
1789          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1790          * We already reported this syscall instruction in
1791          * syscall_trace_enter().
1792          */
1793         step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1794                         !test_thread_flag(TIF_SYSCALL_EMU);
1795         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1796                 tracehook_report_syscall_exit(regs, step);
1797 }