Merge branch 'next-s3c64xx-regs' of git://aeryn.fluff.org.uk/bjdooks/linux into devel
[linux-2.6] / 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
25 #include <asm/uaccess.h>
26 #include <asm/pgtable.h>
27 #include <asm/system.h>
28 #include <asm/processor.h>
29 #include <asm/i387.h>
30 #include <asm/debugreg.h>
31 #include <asm/ldt.h>
32 #include <asm/desc.h>
33 #include <asm/prctl.h>
34 #include <asm/proto.h>
35 #include <asm/ds.h>
36
37 #include "tls.h"
38
39 enum x86_regset {
40         REGSET_GENERAL,
41         REGSET_FP,
42         REGSET_XFP,
43         REGSET_IOPERM64 = REGSET_XFP,
44         REGSET_TLS,
45         REGSET_IOPERM32,
46 };
47
48 /*
49  * does not yet catch signals sent when the child dies.
50  * in exit.c or in signal.c.
51  */
52
53 /*
54  * Determines which flags the user has access to [1 = access, 0 = no access].
55  */
56 #define FLAG_MASK_32            ((unsigned long)                        \
57                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
58                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
59                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
60                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
61                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
62
63 /*
64  * Determines whether a value may be installed in a segment register.
65  */
66 static inline bool invalid_selector(u16 value)
67 {
68         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
69 }
70
71 #ifdef CONFIG_X86_32
72
73 #define FLAG_MASK               FLAG_MASK_32
74
75 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
76 {
77         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
78         regno >>= 2;
79         if (regno > FS)
80                 --regno;
81         return &regs->bx + regno;
82 }
83
84 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
85 {
86         /*
87          * Returning the value truncates it to 16 bits.
88          */
89         unsigned int retval;
90         if (offset != offsetof(struct user_regs_struct, gs))
91                 retval = *pt_regs_access(task_pt_regs(task), offset);
92         else {
93                 retval = task->thread.gs;
94                 if (task == current)
95                         savesegment(gs, retval);
96         }
97         return retval;
98 }
99
100 static int set_segment_reg(struct task_struct *task,
101                            unsigned long offset, u16 value)
102 {
103         /*
104          * The value argument was already truncated to 16 bits.
105          */
106         if (invalid_selector(value))
107                 return -EIO;
108
109         /*
110          * For %cs and %ss we cannot permit a null selector.
111          * We can permit a bogus selector as long as it has USER_RPL.
112          * Null selectors are fine for other segment registers, but
113          * we will never get back to user mode with invalid %cs or %ss
114          * and will take the trap in iret instead.  Much code relies
115          * on user_mode() to distinguish a user trap frame (which can
116          * safely use invalid selectors) from a kernel trap frame.
117          */
118         switch (offset) {
119         case offsetof(struct user_regs_struct, cs):
120         case offsetof(struct user_regs_struct, ss):
121                 if (unlikely(value == 0))
122                         return -EIO;
123
124         default:
125                 *pt_regs_access(task_pt_regs(task), offset) = value;
126                 break;
127
128         case offsetof(struct user_regs_struct, gs):
129                 task->thread.gs = value;
130                 if (task == current)
131                         /*
132                          * The user-mode %gs is not affected by
133                          * kernel entry, so we must update the CPU.
134                          */
135                         loadsegment(gs, value);
136         }
137
138         return 0;
139 }
140
141 static unsigned long debugreg_addr_limit(struct task_struct *task)
142 {
143         return TASK_SIZE - 3;
144 }
145
146 #else  /* CONFIG_X86_64 */
147
148 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
149
150 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
151 {
152         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
153         return &regs->r15 + (offset / sizeof(regs->r15));
154 }
155
156 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
157 {
158         /*
159          * Returning the value truncates it to 16 bits.
160          */
161         unsigned int seg;
162
163         switch (offset) {
164         case offsetof(struct user_regs_struct, fs):
165                 if (task == current) {
166                         /* Older gas can't assemble movq %?s,%r?? */
167                         asm("movl %%fs,%0" : "=r" (seg));
168                         return seg;
169                 }
170                 return task->thread.fsindex;
171         case offsetof(struct user_regs_struct, gs):
172                 if (task == current) {
173                         asm("movl %%gs,%0" : "=r" (seg));
174                         return seg;
175                 }
176                 return task->thread.gsindex;
177         case offsetof(struct user_regs_struct, ds):
178                 if (task == current) {
179                         asm("movl %%ds,%0" : "=r" (seg));
180                         return seg;
181                 }
182                 return task->thread.ds;
183         case offsetof(struct user_regs_struct, es):
184                 if (task == current) {
185                         asm("movl %%es,%0" : "=r" (seg));
186                         return seg;
187                 }
188                 return task->thread.es;
189
190         case offsetof(struct user_regs_struct, cs):
191         case offsetof(struct user_regs_struct, ss):
192                 break;
193         }
194         return *pt_regs_access(task_pt_regs(task), offset);
195 }
196
197 static int set_segment_reg(struct task_struct *task,
198                            unsigned long offset, u16 value)
199 {
200         /*
201          * The value argument was already truncated to 16 bits.
202          */
203         if (invalid_selector(value))
204                 return -EIO;
205
206         switch (offset) {
207         case offsetof(struct user_regs_struct,fs):
208                 /*
209                  * If this is setting fs as for normal 64-bit use but
210                  * setting fs_base has implicitly changed it, leave it.
211                  */
212                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
213                      task->thread.fs != 0) ||
214                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
215                      task->thread.fs == 0))
216                         break;
217                 task->thread.fsindex = value;
218                 if (task == current)
219                         loadsegment(fs, task->thread.fsindex);
220                 break;
221         case offsetof(struct user_regs_struct,gs):
222                 /*
223                  * If this is setting gs as for normal 64-bit use but
224                  * setting gs_base has implicitly changed it, leave it.
225                  */
226                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
227                      task->thread.gs != 0) ||
228                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
229                      task->thread.gs == 0))
230                         break;
231                 task->thread.gsindex = value;
232                 if (task == current)
233                         load_gs_index(task->thread.gsindex);
234                 break;
235         case offsetof(struct user_regs_struct,ds):
236                 task->thread.ds = value;
237                 if (task == current)
238                         loadsegment(ds, task->thread.ds);
239                 break;
240         case offsetof(struct user_regs_struct,es):
241                 task->thread.es = value;
242                 if (task == current)
243                         loadsegment(es, task->thread.es);
244                 break;
245
246                 /*
247                  * Can't actually change these in 64-bit mode.
248                  */
249         case offsetof(struct user_regs_struct,cs):
250                 if (unlikely(value == 0))
251                         return -EIO;
252 #ifdef CONFIG_IA32_EMULATION
253                 if (test_tsk_thread_flag(task, TIF_IA32))
254                         task_pt_regs(task)->cs = value;
255 #endif
256                 break;
257         case offsetof(struct user_regs_struct,ss):
258                 if (unlikely(value == 0))
259                         return -EIO;
260 #ifdef CONFIG_IA32_EMULATION
261                 if (test_tsk_thread_flag(task, TIF_IA32))
262                         task_pt_regs(task)->ss = value;
263 #endif
264                 break;
265         }
266
267         return 0;
268 }
269
270 static unsigned long debugreg_addr_limit(struct task_struct *task)
271 {
272 #ifdef CONFIG_IA32_EMULATION
273         if (test_tsk_thread_flag(task, TIF_IA32))
274                 return IA32_PAGE_OFFSET - 3;
275 #endif
276         return TASK_SIZE64 - 7;
277 }
278
279 #endif  /* CONFIG_X86_32 */
280
281 static unsigned long get_flags(struct task_struct *task)
282 {
283         unsigned long retval = task_pt_regs(task)->flags;
284
285         /*
286          * If the debugger set TF, hide it from the readout.
287          */
288         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
289                 retval &= ~X86_EFLAGS_TF;
290
291         return retval;
292 }
293
294 static int set_flags(struct task_struct *task, unsigned long value)
295 {
296         struct pt_regs *regs = task_pt_regs(task);
297
298         /*
299          * If the user value contains TF, mark that
300          * it was not "us" (the debugger) that set it.
301          * If not, make sure it stays set if we had.
302          */
303         if (value & X86_EFLAGS_TF)
304                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
305         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
306                 value |= X86_EFLAGS_TF;
307
308         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
309
310         return 0;
311 }
312
313 static int putreg(struct task_struct *child,
314                   unsigned long offset, unsigned long value)
315 {
316         switch (offset) {
317         case offsetof(struct user_regs_struct, cs):
318         case offsetof(struct user_regs_struct, ds):
319         case offsetof(struct user_regs_struct, es):
320         case offsetof(struct user_regs_struct, fs):
321         case offsetof(struct user_regs_struct, gs):
322         case offsetof(struct user_regs_struct, ss):
323                 return set_segment_reg(child, offset, value);
324
325         case offsetof(struct user_regs_struct, flags):
326                 return set_flags(child, value);
327
328 #ifdef CONFIG_X86_64
329         /*
330          * Orig_ax is really just a flag with small positive and
331          * negative values, so make sure to always sign-extend it
332          * from 32 bits so that it works correctly regardless of
333          * whether we come from a 32-bit environment or not.
334          */
335         case offsetof(struct user_regs_struct, orig_ax):
336                 value = (long) (s32) value;
337                 break;
338
339         case offsetof(struct user_regs_struct,fs_base):
340                 if (value >= TASK_SIZE_OF(child))
341                         return -EIO;
342                 /*
343                  * When changing the segment base, use do_arch_prctl
344                  * to set either thread.fs or thread.fsindex and the
345                  * corresponding GDT slot.
346                  */
347                 if (child->thread.fs != value)
348                         return do_arch_prctl(child, ARCH_SET_FS, value);
349                 return 0;
350         case offsetof(struct user_regs_struct,gs_base):
351                 /*
352                  * Exactly the same here as the %fs handling above.
353                  */
354                 if (value >= TASK_SIZE_OF(child))
355                         return -EIO;
356                 if (child->thread.gs != value)
357                         return do_arch_prctl(child, ARCH_SET_GS, value);
358                 return 0;
359 #endif
360         }
361
362         *pt_regs_access(task_pt_regs(child), offset) = value;
363         return 0;
364 }
365
366 static unsigned long getreg(struct task_struct *task, unsigned long offset)
367 {
368         switch (offset) {
369         case offsetof(struct user_regs_struct, cs):
370         case offsetof(struct user_regs_struct, ds):
371         case offsetof(struct user_regs_struct, es):
372         case offsetof(struct user_regs_struct, fs):
373         case offsetof(struct user_regs_struct, gs):
374         case offsetof(struct user_regs_struct, ss):
375                 return get_segment_reg(task, offset);
376
377         case offsetof(struct user_regs_struct, flags):
378                 return get_flags(task);
379
380 #ifdef CONFIG_X86_64
381         case offsetof(struct user_regs_struct, fs_base): {
382                 /*
383                  * do_arch_prctl may have used a GDT slot instead of
384                  * the MSR.  To userland, it appears the same either
385                  * way, except the %fs segment selector might not be 0.
386                  */
387                 unsigned int seg = task->thread.fsindex;
388                 if (task->thread.fs != 0)
389                         return task->thread.fs;
390                 if (task == current)
391                         asm("movl %%fs,%0" : "=r" (seg));
392                 if (seg != FS_TLS_SEL)
393                         return 0;
394                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
395         }
396         case offsetof(struct user_regs_struct, gs_base): {
397                 /*
398                  * Exactly the same here as the %fs handling above.
399                  */
400                 unsigned int seg = task->thread.gsindex;
401                 if (task->thread.gs != 0)
402                         return task->thread.gs;
403                 if (task == current)
404                         asm("movl %%gs,%0" : "=r" (seg));
405                 if (seg != GS_TLS_SEL)
406                         return 0;
407                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
408         }
409 #endif
410         }
411
412         return *pt_regs_access(task_pt_regs(task), offset);
413 }
414
415 static int genregs_get(struct task_struct *target,
416                        const struct user_regset *regset,
417                        unsigned int pos, unsigned int count,
418                        void *kbuf, void __user *ubuf)
419 {
420         if (kbuf) {
421                 unsigned long *k = kbuf;
422                 while (count > 0) {
423                         *k++ = getreg(target, pos);
424                         count -= sizeof(*k);
425                         pos += sizeof(*k);
426                 }
427         } else {
428                 unsigned long __user *u = ubuf;
429                 while (count > 0) {
430                         if (__put_user(getreg(target, pos), u++))
431                                 return -EFAULT;
432                         count -= sizeof(*u);
433                         pos += sizeof(*u);
434                 }
435         }
436
437         return 0;
438 }
439
440 static int genregs_set(struct task_struct *target,
441                        const struct user_regset *regset,
442                        unsigned int pos, unsigned int count,
443                        const void *kbuf, const void __user *ubuf)
444 {
445         int ret = 0;
446         if (kbuf) {
447                 const unsigned long *k = kbuf;
448                 while (count > 0 && !ret) {
449                         ret = putreg(target, pos, *k++);
450                         count -= sizeof(*k);
451                         pos += sizeof(*k);
452                 }
453         } else {
454                 const unsigned long  __user *u = ubuf;
455                 while (count > 0 && !ret) {
456                         unsigned long word;
457                         ret = __get_user(word, u++);
458                         if (ret)
459                                 break;
460                         ret = putreg(target, pos, word);
461                         count -= sizeof(*u);
462                         pos += sizeof(*u);
463                 }
464         }
465         return ret;
466 }
467
468 /*
469  * This function is trivial and will be inlined by the compiler.
470  * Having it separates the implementation details of debug
471  * registers from the interface details of ptrace.
472  */
473 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
474 {
475         switch (n) {
476         case 0:         return child->thread.debugreg0;
477         case 1:         return child->thread.debugreg1;
478         case 2:         return child->thread.debugreg2;
479         case 3:         return child->thread.debugreg3;
480         case 6:         return child->thread.debugreg6;
481         case 7:         return child->thread.debugreg7;
482         }
483         return 0;
484 }
485
486 static int ptrace_set_debugreg(struct task_struct *child,
487                                int n, unsigned long data)
488 {
489         int i;
490
491         if (unlikely(n == 4 || n == 5))
492                 return -EIO;
493
494         if (n < 4 && unlikely(data >= debugreg_addr_limit(child)))
495                 return -EIO;
496
497         switch (n) {
498         case 0:         child->thread.debugreg0 = data; break;
499         case 1:         child->thread.debugreg1 = data; break;
500         case 2:         child->thread.debugreg2 = data; break;
501         case 3:         child->thread.debugreg3 = data; break;
502
503         case 6:
504                 if ((data & ~0xffffffffUL) != 0)
505                         return -EIO;
506                 child->thread.debugreg6 = data;
507                 break;
508
509         case 7:
510                 /*
511                  * Sanity-check data. Take one half-byte at once with
512                  * check = (val >> (16 + 4*i)) & 0xf. It contains the
513                  * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
514                  * 2 and 3 are LENi. Given a list of invalid values,
515                  * we do mask |= 1 << invalid_value, so that
516                  * (mask >> check) & 1 is a correct test for invalid
517                  * values.
518                  *
519                  * R/Wi contains the type of the breakpoint /
520                  * watchpoint, LENi contains the length of the watched
521                  * data in the watchpoint case.
522                  *
523                  * The invalid values are:
524                  * - LENi == 0x10 (undefined), so mask |= 0x0f00.       [32-bit]
525                  * - R/Wi == 0x10 (break on I/O reads or writes), so
526                  *   mask |= 0x4444.
527                  * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
528                  *   0x1110.
529                  *
530                  * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
531                  *
532                  * See the Intel Manual "System Programming Guide",
533                  * 15.2.4
534                  *
535                  * Note that LENi == 0x10 is defined on x86_64 in long
536                  * mode (i.e. even for 32-bit userspace software, but
537                  * 64-bit kernel), so the x86_64 mask value is 0x5454.
538                  * See the AMD manual no. 24593 (AMD64 System Programming)
539                  */
540 #ifdef CONFIG_X86_32
541 #define DR7_MASK        0x5f54
542 #else
543 #define DR7_MASK        0x5554
544 #endif
545                 data &= ~DR_CONTROL_RESERVED;
546                 for (i = 0; i < 4; i++)
547                         if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1)
548                                 return -EIO;
549                 child->thread.debugreg7 = data;
550                 if (data)
551                         set_tsk_thread_flag(child, TIF_DEBUG);
552                 else
553                         clear_tsk_thread_flag(child, TIF_DEBUG);
554                 break;
555         }
556
557         return 0;
558 }
559
560 /*
561  * These access the current or another (stopped) task's io permission
562  * bitmap for debugging or core dump.
563  */
564 static int ioperm_active(struct task_struct *target,
565                          const struct user_regset *regset)
566 {
567         return target->thread.io_bitmap_max / regset->size;
568 }
569
570 static int ioperm_get(struct task_struct *target,
571                       const struct user_regset *regset,
572                       unsigned int pos, unsigned int count,
573                       void *kbuf, void __user *ubuf)
574 {
575         if (!target->thread.io_bitmap_ptr)
576                 return -ENXIO;
577
578         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
579                                    target->thread.io_bitmap_ptr,
580                                    0, IO_BITMAP_BYTES);
581 }
582
583 #ifdef CONFIG_X86_PTRACE_BTS
584 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
585                                   struct bts_struct __user *out)
586 {
587         const struct bts_trace *trace;
588         struct bts_struct bts;
589         const unsigned char *at;
590         int error;
591
592         trace = ds_read_bts(child->bts);
593         if (!trace)
594                 return -EPERM;
595
596         at = trace->ds.top - ((index + 1) * trace->ds.size);
597         if ((void *)at < trace->ds.begin)
598                 at += (trace->ds.n * trace->ds.size);
599
600         if (!trace->read)
601                 return -EOPNOTSUPP;
602
603         error = trace->read(child->bts, at, &bts);
604         if (error < 0)
605                 return error;
606
607         if (copy_to_user(out, &bts, sizeof(bts)))
608                 return -EFAULT;
609
610         return sizeof(bts);
611 }
612
613 static int ptrace_bts_drain(struct task_struct *child,
614                             long size,
615                             struct bts_struct __user *out)
616 {
617         const struct bts_trace *trace;
618         const unsigned char *at;
619         int error, drained = 0;
620
621         trace = ds_read_bts(child->bts);
622         if (!trace)
623                 return -EPERM;
624
625         if (!trace->read)
626                 return -EOPNOTSUPP;
627
628         if (size < (trace->ds.top - trace->ds.begin))
629                 return -EIO;
630
631         for (at = trace->ds.begin; (void *)at < trace->ds.top;
632              out++, drained++, at += trace->ds.size) {
633                 struct bts_struct bts;
634                 int error;
635
636                 error = trace->read(child->bts, at, &bts);
637                 if (error < 0)
638                         return error;
639
640                 if (copy_to_user(out, &bts, sizeof(bts)))
641                         return -EFAULT;
642         }
643
644         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
645
646         error = ds_reset_bts(child->bts);
647         if (error < 0)
648                 return error;
649
650         return drained;
651 }
652
653 static int ptrace_bts_allocate_buffer(struct task_struct *child, size_t size)
654 {
655         child->bts_buffer = alloc_locked_buffer(size);
656         if (!child->bts_buffer)
657                 return -ENOMEM;
658
659         child->bts_size = size;
660
661         return 0;
662 }
663
664 static void ptrace_bts_free_buffer(struct task_struct *child)
665 {
666         free_locked_buffer(child->bts_buffer, child->bts_size);
667         child->bts_buffer = NULL;
668         child->bts_size = 0;
669 }
670
671 static int ptrace_bts_config(struct task_struct *child,
672                              long cfg_size,
673                              const struct ptrace_bts_config __user *ucfg)
674 {
675         struct ptrace_bts_config cfg;
676         unsigned int flags = 0;
677
678         if (cfg_size < sizeof(cfg))
679                 return -EIO;
680
681         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
682                 return -EFAULT;
683
684         if (child->bts) {
685                 ds_release_bts(child->bts);
686                 child->bts = NULL;
687         }
688
689         if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
690                 if (!cfg.signal)
691                         return -EINVAL;
692
693                 return -EOPNOTSUPP;
694
695                 child->thread.bts_ovfl_signal = cfg.signal;
696         }
697
698         if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
699             (cfg.size != child->bts_size)) {
700                 int error;
701
702                 ptrace_bts_free_buffer(child);
703
704                 error = ptrace_bts_allocate_buffer(child, cfg.size);
705                 if (error < 0)
706                         return error;
707         }
708
709         if (cfg.flags & PTRACE_BTS_O_TRACE)
710                 flags |= BTS_USER;
711
712         if (cfg.flags & PTRACE_BTS_O_SCHED)
713                 flags |= BTS_TIMESTAMPS;
714
715         child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
716                                     /* ovfl = */ NULL, /* th = */ (size_t)-1,
717                                     flags);
718         if (IS_ERR(child->bts)) {
719                 int error = PTR_ERR(child->bts);
720
721                 ptrace_bts_free_buffer(child);
722                 child->bts = NULL;
723
724                 return error;
725         }
726
727         return sizeof(cfg);
728 }
729
730 static int ptrace_bts_status(struct task_struct *child,
731                              long cfg_size,
732                              struct ptrace_bts_config __user *ucfg)
733 {
734         const struct bts_trace *trace;
735         struct ptrace_bts_config cfg;
736
737         if (cfg_size < sizeof(cfg))
738                 return -EIO;
739
740         trace = ds_read_bts(child->bts);
741         if (!trace)
742                 return -EPERM;
743
744         memset(&cfg, 0, sizeof(cfg));
745         cfg.size = trace->ds.end - trace->ds.begin;
746         cfg.signal = child->thread.bts_ovfl_signal;
747         cfg.bts_size = sizeof(struct bts_struct);
748
749         if (cfg.signal)
750                 cfg.flags |= PTRACE_BTS_O_SIGNAL;
751
752         if (trace->ds.flags & BTS_USER)
753                 cfg.flags |= PTRACE_BTS_O_TRACE;
754
755         if (trace->ds.flags & BTS_TIMESTAMPS)
756                 cfg.flags |= PTRACE_BTS_O_SCHED;
757
758         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
759                 return -EFAULT;
760
761         return sizeof(cfg);
762 }
763
764 static int ptrace_bts_clear(struct task_struct *child)
765 {
766         const struct bts_trace *trace;
767
768         trace = ds_read_bts(child->bts);
769         if (!trace)
770                 return -EPERM;
771
772         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
773
774         return ds_reset_bts(child->bts);
775 }
776
777 static int ptrace_bts_size(struct task_struct *child)
778 {
779         const struct bts_trace *trace;
780
781         trace = ds_read_bts(child->bts);
782         if (!trace)
783                 return -EPERM;
784
785         return (trace->ds.top - trace->ds.begin) / trace->ds.size;
786 }
787
788 static void ptrace_bts_fork(struct task_struct *tsk)
789 {
790         tsk->bts = NULL;
791         tsk->bts_buffer = NULL;
792         tsk->bts_size = 0;
793         tsk->thread.bts_ovfl_signal = 0;
794 }
795
796 static void ptrace_bts_untrace(struct task_struct *child)
797 {
798         if (unlikely(child->bts)) {
799                 ds_release_bts(child->bts);
800                 child->bts = NULL;
801
802                 /* We cannot update total_vm and locked_vm since
803                    child's mm is already gone. But we can reclaim the
804                    memory. */
805                 kfree(child->bts_buffer);
806                 child->bts_buffer = NULL;
807                 child->bts_size = 0;
808         }
809 }
810
811 static void ptrace_bts_detach(struct task_struct *child)
812 {
813         /*
814          * Ptrace_detach() races with ptrace_untrace() in case
815          * the child dies and is reaped by another thread.
816          *
817          * We only do the memory accounting at this point and
818          * leave the buffer deallocation and the bts tracer
819          * release to ptrace_bts_untrace() which will be called
820          * later on with tasklist_lock held.
821          */
822         release_locked_buffer(child->bts_buffer, child->bts_size);
823 }
824 #else
825 static inline void ptrace_bts_fork(struct task_struct *tsk) {}
826 static inline void ptrace_bts_detach(struct task_struct *child) {}
827 static inline void ptrace_bts_untrace(struct task_struct *child) {}
828 #endif /* CONFIG_X86_PTRACE_BTS */
829
830 void x86_ptrace_fork(struct task_struct *child, unsigned long clone_flags)
831 {
832         ptrace_bts_fork(child);
833 }
834
835 void x86_ptrace_untrace(struct task_struct *child)
836 {
837         ptrace_bts_untrace(child);
838 }
839
840 /*
841  * Called by kernel/ptrace.c when detaching..
842  *
843  * Make sure the single step bit is not set.
844  */
845 void ptrace_disable(struct task_struct *child)
846 {
847         user_disable_single_step(child);
848 #ifdef TIF_SYSCALL_EMU
849         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
850 #endif
851         ptrace_bts_detach(child);
852 }
853
854 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
855 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
856 #endif
857
858 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
859 {
860         int ret;
861         unsigned long __user *datap = (unsigned long __user *)data;
862
863         switch (request) {
864         /* read the word at location addr in the USER area. */
865         case PTRACE_PEEKUSR: {
866                 unsigned long tmp;
867
868                 ret = -EIO;
869                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
870                     addr >= sizeof(struct user))
871                         break;
872
873                 tmp = 0;  /* Default return condition */
874                 if (addr < sizeof(struct user_regs_struct))
875                         tmp = getreg(child, addr);
876                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
877                          addr <= offsetof(struct user, u_debugreg[7])) {
878                         addr -= offsetof(struct user, u_debugreg[0]);
879                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
880                 }
881                 ret = put_user(tmp, datap);
882                 break;
883         }
884
885         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
886                 ret = -EIO;
887                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
888                     addr >= sizeof(struct user))
889                         break;
890
891                 if (addr < sizeof(struct user_regs_struct))
892                         ret = putreg(child, addr, data);
893                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
894                          addr <= offsetof(struct user, u_debugreg[7])) {
895                         addr -= offsetof(struct user, u_debugreg[0]);
896                         ret = ptrace_set_debugreg(child,
897                                                   addr / sizeof(data), data);
898                 }
899                 break;
900
901         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
902                 return copy_regset_to_user(child,
903                                            task_user_regset_view(current),
904                                            REGSET_GENERAL,
905                                            0, sizeof(struct user_regs_struct),
906                                            datap);
907
908         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
909                 return copy_regset_from_user(child,
910                                              task_user_regset_view(current),
911                                              REGSET_GENERAL,
912                                              0, sizeof(struct user_regs_struct),
913                                              datap);
914
915         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
916                 return copy_regset_to_user(child,
917                                            task_user_regset_view(current),
918                                            REGSET_FP,
919                                            0, sizeof(struct user_i387_struct),
920                                            datap);
921
922         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
923                 return copy_regset_from_user(child,
924                                              task_user_regset_view(current),
925                                              REGSET_FP,
926                                              0, sizeof(struct user_i387_struct),
927                                              datap);
928
929 #ifdef CONFIG_X86_32
930         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
931                 return copy_regset_to_user(child, &user_x86_32_view,
932                                            REGSET_XFP,
933                                            0, sizeof(struct user_fxsr_struct),
934                                            datap) ? -EIO : 0;
935
936         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
937                 return copy_regset_from_user(child, &user_x86_32_view,
938                                              REGSET_XFP,
939                                              0, sizeof(struct user_fxsr_struct),
940                                              datap) ? -EIO : 0;
941 #endif
942
943 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
944         case PTRACE_GET_THREAD_AREA:
945                 if (addr < 0)
946                         return -EIO;
947                 ret = do_get_thread_area(child, addr,
948                                          (struct user_desc __user *) data);
949                 break;
950
951         case PTRACE_SET_THREAD_AREA:
952                 if (addr < 0)
953                         return -EIO;
954                 ret = do_set_thread_area(child, addr,
955                                          (struct user_desc __user *) data, 0);
956                 break;
957 #endif
958
959 #ifdef CONFIG_X86_64
960                 /* normal 64bit interface to access TLS data.
961                    Works just like arch_prctl, except that the arguments
962                    are reversed. */
963         case PTRACE_ARCH_PRCTL:
964                 ret = do_arch_prctl(child, data, addr);
965                 break;
966 #endif
967
968         /*
969          * These bits need more cooking - not enabled yet:
970          */
971 #ifdef CONFIG_X86_PTRACE_BTS
972         case PTRACE_BTS_CONFIG:
973                 ret = ptrace_bts_config
974                         (child, data, (struct ptrace_bts_config __user *)addr);
975                 break;
976
977         case PTRACE_BTS_STATUS:
978                 ret = ptrace_bts_status
979                         (child, data, (struct ptrace_bts_config __user *)addr);
980                 break;
981
982         case PTRACE_BTS_SIZE:
983                 ret = ptrace_bts_size(child);
984                 break;
985
986         case PTRACE_BTS_GET:
987                 ret = ptrace_bts_read_record
988                         (child, data, (struct bts_struct __user *) addr);
989                 break;
990
991         case PTRACE_BTS_CLEAR:
992                 ret = ptrace_bts_clear(child);
993                 break;
994
995         case PTRACE_BTS_DRAIN:
996                 ret = ptrace_bts_drain
997                         (child, data, (struct bts_struct __user *) addr);
998                 break;
999 #endif /* CONFIG_X86_PTRACE_BTS */
1000
1001         default:
1002                 ret = ptrace_request(child, request, addr, data);
1003                 break;
1004         }
1005
1006         return ret;
1007 }
1008
1009 #ifdef CONFIG_IA32_EMULATION
1010
1011 #include <linux/compat.h>
1012 #include <linux/syscalls.h>
1013 #include <asm/ia32.h>
1014 #include <asm/user32.h>
1015
1016 #define R32(l,q)                                                        \
1017         case offsetof(struct user32, regs.l):                           \
1018                 regs->q = value; break
1019
1020 #define SEG32(rs)                                                       \
1021         case offsetof(struct user32, regs.rs):                          \
1022                 return set_segment_reg(child,                           \
1023                                        offsetof(struct user_regs_struct, rs), \
1024                                        value);                          \
1025                 break
1026
1027 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
1028 {
1029         struct pt_regs *regs = task_pt_regs(child);
1030
1031         switch (regno) {
1032
1033         SEG32(cs);
1034         SEG32(ds);
1035         SEG32(es);
1036         SEG32(fs);
1037         SEG32(gs);
1038         SEG32(ss);
1039
1040         R32(ebx, bx);
1041         R32(ecx, cx);
1042         R32(edx, dx);
1043         R32(edi, di);
1044         R32(esi, si);
1045         R32(ebp, bp);
1046         R32(eax, ax);
1047         R32(eip, ip);
1048         R32(esp, sp);
1049
1050         case offsetof(struct user32, regs.orig_eax):
1051                 /*
1052                  * Sign-extend the value so that orig_eax = -1
1053                  * causes (long)orig_ax < 0 tests to fire correctly.
1054                  */
1055                 regs->orig_ax = (long) (s32) value;
1056                 break;
1057
1058         case offsetof(struct user32, regs.eflags):
1059                 return set_flags(child, value);
1060
1061         case offsetof(struct user32, u_debugreg[0]) ...
1062                 offsetof(struct user32, u_debugreg[7]):
1063                 regno -= offsetof(struct user32, u_debugreg[0]);
1064                 return ptrace_set_debugreg(child, regno / 4, value);
1065
1066         default:
1067                 if (regno > sizeof(struct user32) || (regno & 3))
1068                         return -EIO;
1069
1070                 /*
1071                  * Other dummy fields in the virtual user structure
1072                  * are ignored
1073                  */
1074                 break;
1075         }
1076         return 0;
1077 }
1078
1079 #undef R32
1080 #undef SEG32
1081
1082 #define R32(l,q)                                                        \
1083         case offsetof(struct user32, regs.l):                           \
1084                 *val = regs->q; break
1085
1086 #define SEG32(rs)                                                       \
1087         case offsetof(struct user32, regs.rs):                          \
1088                 *val = get_segment_reg(child,                           \
1089                                        offsetof(struct user_regs_struct, rs)); \
1090                 break
1091
1092 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1093 {
1094         struct pt_regs *regs = task_pt_regs(child);
1095
1096         switch (regno) {
1097
1098         SEG32(ds);
1099         SEG32(es);
1100         SEG32(fs);
1101         SEG32(gs);
1102
1103         R32(cs, cs);
1104         R32(ss, ss);
1105         R32(ebx, bx);
1106         R32(ecx, cx);
1107         R32(edx, dx);
1108         R32(edi, di);
1109         R32(esi, si);
1110         R32(ebp, bp);
1111         R32(eax, ax);
1112         R32(orig_eax, orig_ax);
1113         R32(eip, ip);
1114         R32(esp, sp);
1115
1116         case offsetof(struct user32, regs.eflags):
1117                 *val = get_flags(child);
1118                 break;
1119
1120         case offsetof(struct user32, u_debugreg[0]) ...
1121                 offsetof(struct user32, u_debugreg[7]):
1122                 regno -= offsetof(struct user32, u_debugreg[0]);
1123                 *val = ptrace_get_debugreg(child, regno / 4);
1124                 break;
1125
1126         default:
1127                 if (regno > sizeof(struct user32) || (regno & 3))
1128                         return -EIO;
1129
1130                 /*
1131                  * Other dummy fields in the virtual user structure
1132                  * are ignored
1133                  */
1134                 *val = 0;
1135                 break;
1136         }
1137         return 0;
1138 }
1139
1140 #undef R32
1141 #undef SEG32
1142
1143 static int genregs32_get(struct task_struct *target,
1144                          const struct user_regset *regset,
1145                          unsigned int pos, unsigned int count,
1146                          void *kbuf, void __user *ubuf)
1147 {
1148         if (kbuf) {
1149                 compat_ulong_t *k = kbuf;
1150                 while (count > 0) {
1151                         getreg32(target, pos, k++);
1152                         count -= sizeof(*k);
1153                         pos += sizeof(*k);
1154                 }
1155         } else {
1156                 compat_ulong_t __user *u = ubuf;
1157                 while (count > 0) {
1158                         compat_ulong_t word;
1159                         getreg32(target, pos, &word);
1160                         if (__put_user(word, u++))
1161                                 return -EFAULT;
1162                         count -= sizeof(*u);
1163                         pos += sizeof(*u);
1164                 }
1165         }
1166
1167         return 0;
1168 }
1169
1170 static int genregs32_set(struct task_struct *target,
1171                          const struct user_regset *regset,
1172                          unsigned int pos, unsigned int count,
1173                          const void *kbuf, const void __user *ubuf)
1174 {
1175         int ret = 0;
1176         if (kbuf) {
1177                 const compat_ulong_t *k = kbuf;
1178                 while (count > 0 && !ret) {
1179                         ret = putreg32(target, pos, *k++);
1180                         count -= sizeof(*k);
1181                         pos += sizeof(*k);
1182                 }
1183         } else {
1184                 const compat_ulong_t __user *u = ubuf;
1185                 while (count > 0 && !ret) {
1186                         compat_ulong_t word;
1187                         ret = __get_user(word, u++);
1188                         if (ret)
1189                                 break;
1190                         ret = putreg32(target, pos, word);
1191                         count -= sizeof(*u);
1192                         pos += sizeof(*u);
1193                 }
1194         }
1195         return ret;
1196 }
1197
1198 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1199                         compat_ulong_t caddr, compat_ulong_t cdata)
1200 {
1201         unsigned long addr = caddr;
1202         unsigned long data = cdata;
1203         void __user *datap = compat_ptr(data);
1204         int ret;
1205         __u32 val;
1206
1207         switch (request) {
1208         case PTRACE_PEEKUSR:
1209                 ret = getreg32(child, addr, &val);
1210                 if (ret == 0)
1211                         ret = put_user(val, (__u32 __user *)datap);
1212                 break;
1213
1214         case PTRACE_POKEUSR:
1215                 ret = putreg32(child, addr, data);
1216                 break;
1217
1218         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1219                 return copy_regset_to_user(child, &user_x86_32_view,
1220                                            REGSET_GENERAL,
1221                                            0, sizeof(struct user_regs_struct32),
1222                                            datap);
1223
1224         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1225                 return copy_regset_from_user(child, &user_x86_32_view,
1226                                              REGSET_GENERAL, 0,
1227                                              sizeof(struct user_regs_struct32),
1228                                              datap);
1229
1230         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1231                 return copy_regset_to_user(child, &user_x86_32_view,
1232                                            REGSET_FP, 0,
1233                                            sizeof(struct user_i387_ia32_struct),
1234                                            datap);
1235
1236         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1237                 return copy_regset_from_user(
1238                         child, &user_x86_32_view, REGSET_FP,
1239                         0, sizeof(struct user_i387_ia32_struct), datap);
1240
1241         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1242                 return copy_regset_to_user(child, &user_x86_32_view,
1243                                            REGSET_XFP, 0,
1244                                            sizeof(struct user32_fxsr_struct),
1245                                            datap);
1246
1247         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1248                 return copy_regset_from_user(child, &user_x86_32_view,
1249                                              REGSET_XFP, 0,
1250                                              sizeof(struct user32_fxsr_struct),
1251                                              datap);
1252
1253         case PTRACE_GET_THREAD_AREA:
1254         case PTRACE_SET_THREAD_AREA:
1255 #ifdef CONFIG_X86_PTRACE_BTS
1256         case PTRACE_BTS_CONFIG:
1257         case PTRACE_BTS_STATUS:
1258         case PTRACE_BTS_SIZE:
1259         case PTRACE_BTS_GET:
1260         case PTRACE_BTS_CLEAR:
1261         case PTRACE_BTS_DRAIN:
1262 #endif /* CONFIG_X86_PTRACE_BTS */
1263                 return arch_ptrace(child, request, addr, data);
1264
1265         default:
1266                 return compat_ptrace_request(child, request, addr, data);
1267         }
1268
1269         return ret;
1270 }
1271
1272 #endif  /* CONFIG_IA32_EMULATION */
1273
1274 #ifdef CONFIG_X86_64
1275
1276 static const struct user_regset x86_64_regsets[] = {
1277         [REGSET_GENERAL] = {
1278                 .core_note_type = NT_PRSTATUS,
1279                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1280                 .size = sizeof(long), .align = sizeof(long),
1281                 .get = genregs_get, .set = genregs_set
1282         },
1283         [REGSET_FP] = {
1284                 .core_note_type = NT_PRFPREG,
1285                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1286                 .size = sizeof(long), .align = sizeof(long),
1287                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1288         },
1289         [REGSET_IOPERM64] = {
1290                 .core_note_type = NT_386_IOPERM,
1291                 .n = IO_BITMAP_LONGS,
1292                 .size = sizeof(long), .align = sizeof(long),
1293                 .active = ioperm_active, .get = ioperm_get
1294         },
1295 };
1296
1297 static const struct user_regset_view user_x86_64_view = {
1298         .name = "x86_64", .e_machine = EM_X86_64,
1299         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1300 };
1301
1302 #else  /* CONFIG_X86_32 */
1303
1304 #define user_regs_struct32      user_regs_struct
1305 #define genregs32_get           genregs_get
1306 #define genregs32_set           genregs_set
1307
1308 #define user_i387_ia32_struct   user_i387_struct
1309 #define user32_fxsr_struct      user_fxsr_struct
1310
1311 #endif  /* CONFIG_X86_64 */
1312
1313 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1314 static const struct user_regset x86_32_regsets[] = {
1315         [REGSET_GENERAL] = {
1316                 .core_note_type = NT_PRSTATUS,
1317                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1318                 .size = sizeof(u32), .align = sizeof(u32),
1319                 .get = genregs32_get, .set = genregs32_set
1320         },
1321         [REGSET_FP] = {
1322                 .core_note_type = NT_PRFPREG,
1323                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1324                 .size = sizeof(u32), .align = sizeof(u32),
1325                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1326         },
1327         [REGSET_XFP] = {
1328                 .core_note_type = NT_PRXFPREG,
1329                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1330                 .size = sizeof(u32), .align = sizeof(u32),
1331                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1332         },
1333         [REGSET_TLS] = {
1334                 .core_note_type = NT_386_TLS,
1335                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1336                 .size = sizeof(struct user_desc),
1337                 .align = sizeof(struct user_desc),
1338                 .active = regset_tls_active,
1339                 .get = regset_tls_get, .set = regset_tls_set
1340         },
1341         [REGSET_IOPERM32] = {
1342                 .core_note_type = NT_386_IOPERM,
1343                 .n = IO_BITMAP_BYTES / sizeof(u32),
1344                 .size = sizeof(u32), .align = sizeof(u32),
1345                 .active = ioperm_active, .get = ioperm_get
1346         },
1347 };
1348
1349 static const struct user_regset_view user_x86_32_view = {
1350         .name = "i386", .e_machine = EM_386,
1351         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1352 };
1353 #endif
1354
1355 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1356 {
1357 #ifdef CONFIG_IA32_EMULATION
1358         if (test_tsk_thread_flag(task, TIF_IA32))
1359 #endif
1360 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1361                 return &user_x86_32_view;
1362 #endif
1363 #ifdef CONFIG_X86_64
1364         return &user_x86_64_view;
1365 #endif
1366 }
1367
1368 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1369                                          int error_code, int si_code)
1370 {
1371         struct siginfo info;
1372
1373         tsk->thread.trap_no = 1;
1374         tsk->thread.error_code = error_code;
1375
1376         memset(&info, 0, sizeof(info));
1377         info.si_signo = SIGTRAP;
1378         info.si_code = si_code;
1379
1380         /* User-mode ip? */
1381         info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
1382
1383         /* Send us the fake SIGTRAP */
1384         force_sig_info(SIGTRAP, &info, tsk);
1385 }
1386
1387
1388 #ifdef CONFIG_X86_32
1389 # define IS_IA32        1
1390 #elif defined CONFIG_IA32_EMULATION
1391 # define IS_IA32        is_compat_task()
1392 #else
1393 # define IS_IA32        0
1394 #endif
1395
1396 /*
1397  * We must return the syscall number to actually look up in the table.
1398  * This can be -1L to skip running any syscall at all.
1399  */
1400 asmregparm long syscall_trace_enter(struct pt_regs *regs)
1401 {
1402         long ret = 0;
1403
1404         /*
1405          * If we stepped into a sysenter/syscall insn, it trapped in
1406          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1407          * If user-mode had set TF itself, then it's still clear from
1408          * do_debug() and we need to set it again to restore the user
1409          * state.  If we entered on the slow path, TF was already set.
1410          */
1411         if (test_thread_flag(TIF_SINGLESTEP))
1412                 regs->flags |= X86_EFLAGS_TF;
1413
1414         /* do the secure computing check first */
1415         secure_computing(regs->orig_ax);
1416
1417         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1418                 ret = -1L;
1419
1420         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1421             tracehook_report_syscall_entry(regs))
1422                 ret = -1L;
1423
1424         if (unlikely(current->audit_context)) {
1425                 if (IS_IA32)
1426                         audit_syscall_entry(AUDIT_ARCH_I386,
1427                                             regs->orig_ax,
1428                                             regs->bx, regs->cx,
1429                                             regs->dx, regs->si);
1430 #ifdef CONFIG_X86_64
1431                 else
1432                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1433                                             regs->orig_ax,
1434                                             regs->di, regs->si,
1435                                             regs->dx, regs->r10);
1436 #endif
1437         }
1438
1439         return ret ?: regs->orig_ax;
1440 }
1441
1442 asmregparm void syscall_trace_leave(struct pt_regs *regs)
1443 {
1444         if (unlikely(current->audit_context))
1445                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1446
1447         if (test_thread_flag(TIF_SYSCALL_TRACE))
1448                 tracehook_report_syscall_exit(regs, 0);
1449
1450         /*
1451          * If TIF_SYSCALL_EMU is set, we only get here because of
1452          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1453          * We already reported this syscall instruction in
1454          * syscall_trace_enter(), so don't do any more now.
1455          */
1456         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1457                 return;
1458
1459         /*
1460          * If we are single-stepping, synthesize a trap to follow the
1461          * system call instruction.
1462          */
1463         if (test_thread_flag(TIF_SINGLESTEP) &&
1464             tracehook_consider_fatal_signal(current, SIGTRAP, SIG_DFL))
1465                 send_sigtrap(current, regs, 0, TRAP_BRKPT);
1466 }