Merge branch 'tracing/core-v2' into tracing-for-linus
[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/ftrace.h>
25
26 #include <asm/uaccess.h>
27 #include <asm/pgtable.h>
28 #include <asm/system.h>
29 #include <asm/processor.h>
30 #include <asm/i387.h>
31 #include <asm/debugreg.h>
32 #include <asm/ldt.h>
33 #include <asm/desc.h>
34 #include <asm/prctl.h>
35 #include <asm/proto.h>
36 #include <asm/ds.h>
37
38 #include "tls.h"
39
40 enum x86_regset {
41         REGSET_GENERAL,
42         REGSET_FP,
43         REGSET_XFP,
44         REGSET_IOPERM64 = REGSET_XFP,
45         REGSET_TLS,
46         REGSET_IOPERM32,
47 };
48
49 /*
50  * does not yet catch signals sent when the child dies.
51  * in exit.c or in signal.c.
52  */
53
54 /*
55  * Determines which flags the user has access to [1 = access, 0 = no access].
56  */
57 #define FLAG_MASK_32            ((unsigned long)                        \
58                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
59                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
60                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
61                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
62                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
63
64 /*
65  * Determines whether a value may be installed in a segment register.
66  */
67 static inline bool invalid_selector(u16 value)
68 {
69         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
70 }
71
72 #ifdef CONFIG_X86_32
73
74 #define FLAG_MASK               FLAG_MASK_32
75
76 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
77 {
78         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
79         return &regs->bx + (regno >> 2);
80 }
81
82 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
83 {
84         /*
85          * Returning the value truncates it to 16 bits.
86          */
87         unsigned int retval;
88         if (offset != offsetof(struct user_regs_struct, gs))
89                 retval = *pt_regs_access(task_pt_regs(task), offset);
90         else {
91                 if (task == current)
92                         retval = get_user_gs(task_pt_regs(task));
93                 else
94                         retval = task_user_gs(task);
95         }
96         return retval;
97 }
98
99 static int set_segment_reg(struct task_struct *task,
100                            unsigned long offset, u16 value)
101 {
102         /*
103          * The value argument was already truncated to 16 bits.
104          */
105         if (invalid_selector(value))
106                 return -EIO;
107
108         /*
109          * For %cs and %ss we cannot permit a null selector.
110          * We can permit a bogus selector as long as it has USER_RPL.
111          * Null selectors are fine for other segment registers, but
112          * we will never get back to user mode with invalid %cs or %ss
113          * and will take the trap in iret instead.  Much code relies
114          * on user_mode() to distinguish a user trap frame (which can
115          * safely use invalid selectors) from a kernel trap frame.
116          */
117         switch (offset) {
118         case offsetof(struct user_regs_struct, cs):
119         case offsetof(struct user_regs_struct, ss):
120                 if (unlikely(value == 0))
121                         return -EIO;
122
123         default:
124                 *pt_regs_access(task_pt_regs(task), offset) = value;
125                 break;
126
127         case offsetof(struct user_regs_struct, gs):
128                 if (task == current)
129                         set_user_gs(task_pt_regs(task), value);
130                 else
131                         task_user_gs(task) = value;
132         }
133
134         return 0;
135 }
136
137 static unsigned long debugreg_addr_limit(struct task_struct *task)
138 {
139         return TASK_SIZE - 3;
140 }
141
142 #else  /* CONFIG_X86_64 */
143
144 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
145
146 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
147 {
148         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
149         return &regs->r15 + (offset / sizeof(regs->r15));
150 }
151
152 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
153 {
154         /*
155          * Returning the value truncates it to 16 bits.
156          */
157         unsigned int seg;
158
159         switch (offset) {
160         case offsetof(struct user_regs_struct, fs):
161                 if (task == current) {
162                         /* Older gas can't assemble movq %?s,%r?? */
163                         asm("movl %%fs,%0" : "=r" (seg));
164                         return seg;
165                 }
166                 return task->thread.fsindex;
167         case offsetof(struct user_regs_struct, gs):
168                 if (task == current) {
169                         asm("movl %%gs,%0" : "=r" (seg));
170                         return seg;
171                 }
172                 return task->thread.gsindex;
173         case offsetof(struct user_regs_struct, ds):
174                 if (task == current) {
175                         asm("movl %%ds,%0" : "=r" (seg));
176                         return seg;
177                 }
178                 return task->thread.ds;
179         case offsetof(struct user_regs_struct, es):
180                 if (task == current) {
181                         asm("movl %%es,%0" : "=r" (seg));
182                         return seg;
183                 }
184                 return task->thread.es;
185
186         case offsetof(struct user_regs_struct, cs):
187         case offsetof(struct user_regs_struct, ss):
188                 break;
189         }
190         return *pt_regs_access(task_pt_regs(task), offset);
191 }
192
193 static int set_segment_reg(struct task_struct *task,
194                            unsigned long offset, u16 value)
195 {
196         /*
197          * The value argument was already truncated to 16 bits.
198          */
199         if (invalid_selector(value))
200                 return -EIO;
201
202         switch (offset) {
203         case offsetof(struct user_regs_struct,fs):
204                 /*
205                  * If this is setting fs as for normal 64-bit use but
206                  * setting fs_base has implicitly changed it, leave it.
207                  */
208                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
209                      task->thread.fs != 0) ||
210                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
211                      task->thread.fs == 0))
212                         break;
213                 task->thread.fsindex = value;
214                 if (task == current)
215                         loadsegment(fs, task->thread.fsindex);
216                 break;
217         case offsetof(struct user_regs_struct,gs):
218                 /*
219                  * If this is setting gs as for normal 64-bit use but
220                  * setting gs_base has implicitly changed it, leave it.
221                  */
222                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
223                      task->thread.gs != 0) ||
224                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
225                      task->thread.gs == 0))
226                         break;
227                 task->thread.gsindex = value;
228                 if (task == current)
229                         load_gs_index(task->thread.gsindex);
230                 break;
231         case offsetof(struct user_regs_struct,ds):
232                 task->thread.ds = value;
233                 if (task == current)
234                         loadsegment(ds, task->thread.ds);
235                 break;
236         case offsetof(struct user_regs_struct,es):
237                 task->thread.es = value;
238                 if (task == current)
239                         loadsegment(es, task->thread.es);
240                 break;
241
242                 /*
243                  * Can't actually change these in 64-bit mode.
244                  */
245         case offsetof(struct user_regs_struct,cs):
246                 if (unlikely(value == 0))
247                         return -EIO;
248 #ifdef CONFIG_IA32_EMULATION
249                 if (test_tsk_thread_flag(task, TIF_IA32))
250                         task_pt_regs(task)->cs = value;
251 #endif
252                 break;
253         case offsetof(struct user_regs_struct,ss):
254                 if (unlikely(value == 0))
255                         return -EIO;
256 #ifdef CONFIG_IA32_EMULATION
257                 if (test_tsk_thread_flag(task, TIF_IA32))
258                         task_pt_regs(task)->ss = value;
259 #endif
260                 break;
261         }
262
263         return 0;
264 }
265
266 static unsigned long debugreg_addr_limit(struct task_struct *task)
267 {
268 #ifdef CONFIG_IA32_EMULATION
269         if (test_tsk_thread_flag(task, TIF_IA32))
270                 return IA32_PAGE_OFFSET - 3;
271 #endif
272         return TASK_SIZE_MAX - 7;
273 }
274
275 #endif  /* CONFIG_X86_32 */
276
277 static unsigned long get_flags(struct task_struct *task)
278 {
279         unsigned long retval = task_pt_regs(task)->flags;
280
281         /*
282          * If the debugger set TF, hide it from the readout.
283          */
284         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
285                 retval &= ~X86_EFLAGS_TF;
286
287         return retval;
288 }
289
290 static int set_flags(struct task_struct *task, unsigned long value)
291 {
292         struct pt_regs *regs = task_pt_regs(task);
293
294         /*
295          * If the user value contains TF, mark that
296          * it was not "us" (the debugger) that set it.
297          * If not, make sure it stays set if we had.
298          */
299         if (value & X86_EFLAGS_TF)
300                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
301         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
302                 value |= X86_EFLAGS_TF;
303
304         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
305
306         return 0;
307 }
308
309 static int putreg(struct task_struct *child,
310                   unsigned long offset, unsigned long value)
311 {
312         switch (offset) {
313         case offsetof(struct user_regs_struct, cs):
314         case offsetof(struct user_regs_struct, ds):
315         case offsetof(struct user_regs_struct, es):
316         case offsetof(struct user_regs_struct, fs):
317         case offsetof(struct user_regs_struct, gs):
318         case offsetof(struct user_regs_struct, ss):
319                 return set_segment_reg(child, offset, value);
320
321         case offsetof(struct user_regs_struct, flags):
322                 return set_flags(child, value);
323
324 #ifdef CONFIG_X86_64
325         /*
326          * Orig_ax is really just a flag with small positive and
327          * negative values, so make sure to always sign-extend it
328          * from 32 bits so that it works correctly regardless of
329          * whether we come from a 32-bit environment or not.
330          */
331         case offsetof(struct user_regs_struct, orig_ax):
332                 value = (long) (s32) value;
333                 break;
334
335         case offsetof(struct user_regs_struct,fs_base):
336                 if (value >= TASK_SIZE_OF(child))
337                         return -EIO;
338                 /*
339                  * When changing the segment base, use do_arch_prctl
340                  * to set either thread.fs or thread.fsindex and the
341                  * corresponding GDT slot.
342                  */
343                 if (child->thread.fs != value)
344                         return do_arch_prctl(child, ARCH_SET_FS, value);
345                 return 0;
346         case offsetof(struct user_regs_struct,gs_base):
347                 /*
348                  * Exactly the same here as the %fs handling above.
349                  */
350                 if (value >= TASK_SIZE_OF(child))
351                         return -EIO;
352                 if (child->thread.gs != value)
353                         return do_arch_prctl(child, ARCH_SET_GS, value);
354                 return 0;
355 #endif
356         }
357
358         *pt_regs_access(task_pt_regs(child), offset) = value;
359         return 0;
360 }
361
362 static unsigned long getreg(struct task_struct *task, unsigned long offset)
363 {
364         switch (offset) {
365         case offsetof(struct user_regs_struct, cs):
366         case offsetof(struct user_regs_struct, ds):
367         case offsetof(struct user_regs_struct, es):
368         case offsetof(struct user_regs_struct, fs):
369         case offsetof(struct user_regs_struct, gs):
370         case offsetof(struct user_regs_struct, ss):
371                 return get_segment_reg(task, offset);
372
373         case offsetof(struct user_regs_struct, flags):
374                 return get_flags(task);
375
376 #ifdef CONFIG_X86_64
377         case offsetof(struct user_regs_struct, fs_base): {
378                 /*
379                  * do_arch_prctl may have used a GDT slot instead of
380                  * the MSR.  To userland, it appears the same either
381                  * way, except the %fs segment selector might not be 0.
382                  */
383                 unsigned int seg = task->thread.fsindex;
384                 if (task->thread.fs != 0)
385                         return task->thread.fs;
386                 if (task == current)
387                         asm("movl %%fs,%0" : "=r" (seg));
388                 if (seg != FS_TLS_SEL)
389                         return 0;
390                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
391         }
392         case offsetof(struct user_regs_struct, gs_base): {
393                 /*
394                  * Exactly the same here as the %fs handling above.
395                  */
396                 unsigned int seg = task->thread.gsindex;
397                 if (task->thread.gs != 0)
398                         return task->thread.gs;
399                 if (task == current)
400                         asm("movl %%gs,%0" : "=r" (seg));
401                 if (seg != GS_TLS_SEL)
402                         return 0;
403                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
404         }
405 #endif
406         }
407
408         return *pt_regs_access(task_pt_regs(task), offset);
409 }
410
411 static int genregs_get(struct task_struct *target,
412                        const struct user_regset *regset,
413                        unsigned int pos, unsigned int count,
414                        void *kbuf, void __user *ubuf)
415 {
416         if (kbuf) {
417                 unsigned long *k = kbuf;
418                 while (count > 0) {
419                         *k++ = getreg(target, pos);
420                         count -= sizeof(*k);
421                         pos += sizeof(*k);
422                 }
423         } else {
424                 unsigned long __user *u = ubuf;
425                 while (count > 0) {
426                         if (__put_user(getreg(target, pos), u++))
427                                 return -EFAULT;
428                         count -= sizeof(*u);
429                         pos += sizeof(*u);
430                 }
431         }
432
433         return 0;
434 }
435
436 static int genregs_set(struct task_struct *target,
437                        const struct user_regset *regset,
438                        unsigned int pos, unsigned int count,
439                        const void *kbuf, const void __user *ubuf)
440 {
441         int ret = 0;
442         if (kbuf) {
443                 const unsigned long *k = kbuf;
444                 while (count > 0 && !ret) {
445                         ret = putreg(target, pos, *k++);
446                         count -= sizeof(*k);
447                         pos += sizeof(*k);
448                 }
449         } else {
450                 const unsigned long  __user *u = ubuf;
451                 while (count > 0 && !ret) {
452                         unsigned long word;
453                         ret = __get_user(word, u++);
454                         if (ret)
455                                 break;
456                         ret = putreg(target, pos, word);
457                         count -= sizeof(*u);
458                         pos += sizeof(*u);
459                 }
460         }
461         return ret;
462 }
463
464 /*
465  * This function is trivial and will be inlined by the compiler.
466  * Having it separates the implementation details of debug
467  * registers from the interface details of ptrace.
468  */
469 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
470 {
471         switch (n) {
472         case 0:         return child->thread.debugreg0;
473         case 1:         return child->thread.debugreg1;
474         case 2:         return child->thread.debugreg2;
475         case 3:         return child->thread.debugreg3;
476         case 6:         return child->thread.debugreg6;
477         case 7:         return child->thread.debugreg7;
478         }
479         return 0;
480 }
481
482 static int ptrace_set_debugreg(struct task_struct *child,
483                                int n, unsigned long data)
484 {
485         int i;
486
487         if (unlikely(n == 4 || n == 5))
488                 return -EIO;
489
490         if (n < 4 && unlikely(data >= debugreg_addr_limit(child)))
491                 return -EIO;
492
493         switch (n) {
494         case 0:         child->thread.debugreg0 = data; break;
495         case 1:         child->thread.debugreg1 = data; break;
496         case 2:         child->thread.debugreg2 = data; break;
497         case 3:         child->thread.debugreg3 = data; break;
498
499         case 6:
500                 if ((data & ~0xffffffffUL) != 0)
501                         return -EIO;
502                 child->thread.debugreg6 = data;
503                 break;
504
505         case 7:
506                 /*
507                  * Sanity-check data. Take one half-byte at once with
508                  * check = (val >> (16 + 4*i)) & 0xf. It contains the
509                  * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
510                  * 2 and 3 are LENi. Given a list of invalid values,
511                  * we do mask |= 1 << invalid_value, so that
512                  * (mask >> check) & 1 is a correct test for invalid
513                  * values.
514                  *
515                  * R/Wi contains the type of the breakpoint /
516                  * watchpoint, LENi contains the length of the watched
517                  * data in the watchpoint case.
518                  *
519                  * The invalid values are:
520                  * - LENi == 0x10 (undefined), so mask |= 0x0f00.       [32-bit]
521                  * - R/Wi == 0x10 (break on I/O reads or writes), so
522                  *   mask |= 0x4444.
523                  * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
524                  *   0x1110.
525                  *
526                  * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
527                  *
528                  * See the Intel Manual "System Programming Guide",
529                  * 15.2.4
530                  *
531                  * Note that LENi == 0x10 is defined on x86_64 in long
532                  * mode (i.e. even for 32-bit userspace software, but
533                  * 64-bit kernel), so the x86_64 mask value is 0x5454.
534                  * See the AMD manual no. 24593 (AMD64 System Programming)
535                  */
536 #ifdef CONFIG_X86_32
537 #define DR7_MASK        0x5f54
538 #else
539 #define DR7_MASK        0x5554
540 #endif
541                 data &= ~DR_CONTROL_RESERVED;
542                 for (i = 0; i < 4; i++)
543                         if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1)
544                                 return -EIO;
545                 child->thread.debugreg7 = data;
546                 if (data)
547                         set_tsk_thread_flag(child, TIF_DEBUG);
548                 else
549                         clear_tsk_thread_flag(child, TIF_DEBUG);
550                 break;
551         }
552
553         return 0;
554 }
555
556 /*
557  * These access the current or another (stopped) task's io permission
558  * bitmap for debugging or core dump.
559  */
560 static int ioperm_active(struct task_struct *target,
561                          const struct user_regset *regset)
562 {
563         return target->thread.io_bitmap_max / regset->size;
564 }
565
566 static int ioperm_get(struct task_struct *target,
567                       const struct user_regset *regset,
568                       unsigned int pos, unsigned int count,
569                       void *kbuf, void __user *ubuf)
570 {
571         if (!target->thread.io_bitmap_ptr)
572                 return -ENXIO;
573
574         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
575                                    target->thread.io_bitmap_ptr,
576                                    0, IO_BITMAP_BYTES);
577 }
578
579 #ifdef CONFIG_X86_PTRACE_BTS
580 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
581                                   struct bts_struct __user *out)
582 {
583         const struct bts_trace *trace;
584         struct bts_struct bts;
585         const unsigned char *at;
586         int error;
587
588         trace = ds_read_bts(child->bts);
589         if (!trace)
590                 return -EPERM;
591
592         at = trace->ds.top - ((index + 1) * trace->ds.size);
593         if ((void *)at < trace->ds.begin)
594                 at += (trace->ds.n * trace->ds.size);
595
596         if (!trace->read)
597                 return -EOPNOTSUPP;
598
599         error = trace->read(child->bts, at, &bts);
600         if (error < 0)
601                 return error;
602
603         if (copy_to_user(out, &bts, sizeof(bts)))
604                 return -EFAULT;
605
606         return sizeof(bts);
607 }
608
609 static int ptrace_bts_drain(struct task_struct *child,
610                             long size,
611                             struct bts_struct __user *out)
612 {
613         const struct bts_trace *trace;
614         const unsigned char *at;
615         int error, drained = 0;
616
617         trace = ds_read_bts(child->bts);
618         if (!trace)
619                 return -EPERM;
620
621         if (!trace->read)
622                 return -EOPNOTSUPP;
623
624         if (size < (trace->ds.top - trace->ds.begin))
625                 return -EIO;
626
627         for (at = trace->ds.begin; (void *)at < trace->ds.top;
628              out++, drained++, at += trace->ds.size) {
629                 struct bts_struct bts;
630                 int error;
631
632                 error = trace->read(child->bts, at, &bts);
633                 if (error < 0)
634                         return error;
635
636                 if (copy_to_user(out, &bts, sizeof(bts)))
637                         return -EFAULT;
638         }
639
640         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
641
642         error = ds_reset_bts(child->bts);
643         if (error < 0)
644                 return error;
645
646         return drained;
647 }
648
649 static int ptrace_bts_allocate_buffer(struct task_struct *child, size_t size)
650 {
651         child->bts_buffer = alloc_locked_buffer(size);
652         if (!child->bts_buffer)
653                 return -ENOMEM;
654
655         child->bts_size = size;
656
657         return 0;
658 }
659
660 static void ptrace_bts_free_buffer(struct task_struct *child)
661 {
662         free_locked_buffer(child->bts_buffer, child->bts_size);
663         child->bts_buffer = NULL;
664         child->bts_size = 0;
665 }
666
667 static int ptrace_bts_config(struct task_struct *child,
668                              long cfg_size,
669                              const struct ptrace_bts_config __user *ucfg)
670 {
671         struct ptrace_bts_config cfg;
672         unsigned int flags = 0;
673
674         if (cfg_size < sizeof(cfg))
675                 return -EIO;
676
677         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
678                 return -EFAULT;
679
680         if (child->bts) {
681                 ds_release_bts(child->bts);
682                 child->bts = NULL;
683         }
684
685         if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
686                 if (!cfg.signal)
687                         return -EINVAL;
688
689                 child->thread.bts_ovfl_signal = cfg.signal;
690                 return -EOPNOTSUPP;
691         }
692
693         if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
694             (cfg.size != child->bts_size)) {
695                 int error;
696
697                 ptrace_bts_free_buffer(child);
698
699                 error = ptrace_bts_allocate_buffer(child, cfg.size);
700                 if (error < 0)
701                         return error;
702         }
703
704         if (cfg.flags & PTRACE_BTS_O_TRACE)
705                 flags |= BTS_USER;
706
707         if (cfg.flags & PTRACE_BTS_O_SCHED)
708                 flags |= BTS_TIMESTAMPS;
709
710         child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
711                                     /* ovfl = */ NULL, /* th = */ (size_t)-1,
712                                     flags);
713         if (IS_ERR(child->bts)) {
714                 int error = PTR_ERR(child->bts);
715
716                 ptrace_bts_free_buffer(child);
717                 child->bts = NULL;
718
719                 return error;
720         }
721
722         return sizeof(cfg);
723 }
724
725 static int ptrace_bts_status(struct task_struct *child,
726                              long cfg_size,
727                              struct ptrace_bts_config __user *ucfg)
728 {
729         const struct bts_trace *trace;
730         struct ptrace_bts_config cfg;
731
732         if (cfg_size < sizeof(cfg))
733                 return -EIO;
734
735         trace = ds_read_bts(child->bts);
736         if (!trace)
737                 return -EPERM;
738
739         memset(&cfg, 0, sizeof(cfg));
740         cfg.size = trace->ds.end - trace->ds.begin;
741         cfg.signal = child->thread.bts_ovfl_signal;
742         cfg.bts_size = sizeof(struct bts_struct);
743
744         if (cfg.signal)
745                 cfg.flags |= PTRACE_BTS_O_SIGNAL;
746
747         if (trace->ds.flags & BTS_USER)
748                 cfg.flags |= PTRACE_BTS_O_TRACE;
749
750         if (trace->ds.flags & BTS_TIMESTAMPS)
751                 cfg.flags |= PTRACE_BTS_O_SCHED;
752
753         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
754                 return -EFAULT;
755
756         return sizeof(cfg);
757 }
758
759 static int ptrace_bts_clear(struct task_struct *child)
760 {
761         const struct bts_trace *trace;
762
763         trace = ds_read_bts(child->bts);
764         if (!trace)
765                 return -EPERM;
766
767         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
768
769         return ds_reset_bts(child->bts);
770 }
771
772 static int ptrace_bts_size(struct task_struct *child)
773 {
774         const struct bts_trace *trace;
775
776         trace = ds_read_bts(child->bts);
777         if (!trace)
778                 return -EPERM;
779
780         return (trace->ds.top - trace->ds.begin) / trace->ds.size;
781 }
782
783 static void ptrace_bts_fork(struct task_struct *tsk)
784 {
785         tsk->bts = NULL;
786         tsk->bts_buffer = NULL;
787         tsk->bts_size = 0;
788         tsk->thread.bts_ovfl_signal = 0;
789 }
790
791 static void ptrace_bts_untrace(struct task_struct *child)
792 {
793         if (unlikely(child->bts)) {
794                 ds_release_bts(child->bts);
795                 child->bts = NULL;
796
797                 /* We cannot update total_vm and locked_vm since
798                    child's mm is already gone. But we can reclaim the
799                    memory. */
800                 kfree(child->bts_buffer);
801                 child->bts_buffer = NULL;
802                 child->bts_size = 0;
803         }
804 }
805
806 static void ptrace_bts_detach(struct task_struct *child)
807 {
808         /*
809          * Ptrace_detach() races with ptrace_untrace() in case
810          * the child dies and is reaped by another thread.
811          *
812          * We only do the memory accounting at this point and
813          * leave the buffer deallocation and the bts tracer
814          * release to ptrace_bts_untrace() which will be called
815          * later on with tasklist_lock held.
816          */
817         release_locked_buffer(child->bts_buffer, child->bts_size);
818 }
819 #else
820 static inline void ptrace_bts_fork(struct task_struct *tsk) {}
821 static inline void ptrace_bts_detach(struct task_struct *child) {}
822 static inline void ptrace_bts_untrace(struct task_struct *child) {}
823 #endif /* CONFIG_X86_PTRACE_BTS */
824
825 void x86_ptrace_fork(struct task_struct *child, unsigned long clone_flags)
826 {
827         ptrace_bts_fork(child);
828 }
829
830 void x86_ptrace_untrace(struct task_struct *child)
831 {
832         ptrace_bts_untrace(child);
833 }
834
835 /*
836  * Called by kernel/ptrace.c when detaching..
837  *
838  * Make sure the single step bit is not set.
839  */
840 void ptrace_disable(struct task_struct *child)
841 {
842         user_disable_single_step(child);
843 #ifdef TIF_SYSCALL_EMU
844         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
845 #endif
846         ptrace_bts_detach(child);
847 }
848
849 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
850 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
851 #endif
852
853 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
854 {
855         int ret;
856         unsigned long __user *datap = (unsigned long __user *)data;
857
858         switch (request) {
859         /* read the word at location addr in the USER area. */
860         case PTRACE_PEEKUSR: {
861                 unsigned long tmp;
862
863                 ret = -EIO;
864                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
865                     addr >= sizeof(struct user))
866                         break;
867
868                 tmp = 0;  /* Default return condition */
869                 if (addr < sizeof(struct user_regs_struct))
870                         tmp = getreg(child, addr);
871                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
872                          addr <= offsetof(struct user, u_debugreg[7])) {
873                         addr -= offsetof(struct user, u_debugreg[0]);
874                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
875                 }
876                 ret = put_user(tmp, datap);
877                 break;
878         }
879
880         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
881                 ret = -EIO;
882                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
883                     addr >= sizeof(struct user))
884                         break;
885
886                 if (addr < sizeof(struct user_regs_struct))
887                         ret = putreg(child, addr, data);
888                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
889                          addr <= offsetof(struct user, u_debugreg[7])) {
890                         addr -= offsetof(struct user, u_debugreg[0]);
891                         ret = ptrace_set_debugreg(child,
892                                                   addr / sizeof(data), data);
893                 }
894                 break;
895
896         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
897                 return copy_regset_to_user(child,
898                                            task_user_regset_view(current),
899                                            REGSET_GENERAL,
900                                            0, sizeof(struct user_regs_struct),
901                                            datap);
902
903         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
904                 return copy_regset_from_user(child,
905                                              task_user_regset_view(current),
906                                              REGSET_GENERAL,
907                                              0, sizeof(struct user_regs_struct),
908                                              datap);
909
910         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
911                 return copy_regset_to_user(child,
912                                            task_user_regset_view(current),
913                                            REGSET_FP,
914                                            0, sizeof(struct user_i387_struct),
915                                            datap);
916
917         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
918                 return copy_regset_from_user(child,
919                                              task_user_regset_view(current),
920                                              REGSET_FP,
921                                              0, sizeof(struct user_i387_struct),
922                                              datap);
923
924 #ifdef CONFIG_X86_32
925         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
926                 return copy_regset_to_user(child, &user_x86_32_view,
927                                            REGSET_XFP,
928                                            0, sizeof(struct user_fxsr_struct),
929                                            datap) ? -EIO : 0;
930
931         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
932                 return copy_regset_from_user(child, &user_x86_32_view,
933                                              REGSET_XFP,
934                                              0, sizeof(struct user_fxsr_struct),
935                                              datap) ? -EIO : 0;
936 #endif
937
938 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
939         case PTRACE_GET_THREAD_AREA:
940                 if (addr < 0)
941                         return -EIO;
942                 ret = do_get_thread_area(child, addr,
943                                          (struct user_desc __user *) data);
944                 break;
945
946         case PTRACE_SET_THREAD_AREA:
947                 if (addr < 0)
948                         return -EIO;
949                 ret = do_set_thread_area(child, addr,
950                                          (struct user_desc __user *) data, 0);
951                 break;
952 #endif
953
954 #ifdef CONFIG_X86_64
955                 /* normal 64bit interface to access TLS data.
956                    Works just like arch_prctl, except that the arguments
957                    are reversed. */
958         case PTRACE_ARCH_PRCTL:
959                 ret = do_arch_prctl(child, data, addr);
960                 break;
961 #endif
962
963         /*
964          * These bits need more cooking - not enabled yet:
965          */
966 #ifdef CONFIG_X86_PTRACE_BTS
967         case PTRACE_BTS_CONFIG:
968                 ret = ptrace_bts_config
969                         (child, data, (struct ptrace_bts_config __user *)addr);
970                 break;
971
972         case PTRACE_BTS_STATUS:
973                 ret = ptrace_bts_status
974                         (child, data, (struct ptrace_bts_config __user *)addr);
975                 break;
976
977         case PTRACE_BTS_SIZE:
978                 ret = ptrace_bts_size(child);
979                 break;
980
981         case PTRACE_BTS_GET:
982                 ret = ptrace_bts_read_record
983                         (child, data, (struct bts_struct __user *) addr);
984                 break;
985
986         case PTRACE_BTS_CLEAR:
987                 ret = ptrace_bts_clear(child);
988                 break;
989
990         case PTRACE_BTS_DRAIN:
991                 ret = ptrace_bts_drain
992                         (child, data, (struct bts_struct __user *) addr);
993                 break;
994 #endif /* CONFIG_X86_PTRACE_BTS */
995
996         default:
997                 ret = ptrace_request(child, request, addr, data);
998                 break;
999         }
1000
1001         return ret;
1002 }
1003
1004 #ifdef CONFIG_IA32_EMULATION
1005
1006 #include <linux/compat.h>
1007 #include <linux/syscalls.h>
1008 #include <asm/ia32.h>
1009 #include <asm/user32.h>
1010
1011 #define R32(l,q)                                                        \
1012         case offsetof(struct user32, regs.l):                           \
1013                 regs->q = value; break
1014
1015 #define SEG32(rs)                                                       \
1016         case offsetof(struct user32, regs.rs):                          \
1017                 return set_segment_reg(child,                           \
1018                                        offsetof(struct user_regs_struct, rs), \
1019                                        value);                          \
1020                 break
1021
1022 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
1023 {
1024         struct pt_regs *regs = task_pt_regs(child);
1025
1026         switch (regno) {
1027
1028         SEG32(cs);
1029         SEG32(ds);
1030         SEG32(es);
1031         SEG32(fs);
1032         SEG32(gs);
1033         SEG32(ss);
1034
1035         R32(ebx, bx);
1036         R32(ecx, cx);
1037         R32(edx, dx);
1038         R32(edi, di);
1039         R32(esi, si);
1040         R32(ebp, bp);
1041         R32(eax, ax);
1042         R32(eip, ip);
1043         R32(esp, sp);
1044
1045         case offsetof(struct user32, regs.orig_eax):
1046                 /*
1047                  * Sign-extend the value so that orig_eax = -1
1048                  * causes (long)orig_ax < 0 tests to fire correctly.
1049                  */
1050                 regs->orig_ax = (long) (s32) value;
1051                 break;
1052
1053         case offsetof(struct user32, regs.eflags):
1054                 return set_flags(child, value);
1055
1056         case offsetof(struct user32, u_debugreg[0]) ...
1057                 offsetof(struct user32, u_debugreg[7]):
1058                 regno -= offsetof(struct user32, u_debugreg[0]);
1059                 return ptrace_set_debugreg(child, regno / 4, value);
1060
1061         default:
1062                 if (regno > sizeof(struct user32) || (regno & 3))
1063                         return -EIO;
1064
1065                 /*
1066                  * Other dummy fields in the virtual user structure
1067                  * are ignored
1068                  */
1069                 break;
1070         }
1071         return 0;
1072 }
1073
1074 #undef R32
1075 #undef SEG32
1076
1077 #define R32(l,q)                                                        \
1078         case offsetof(struct user32, regs.l):                           \
1079                 *val = regs->q; break
1080
1081 #define SEG32(rs)                                                       \
1082         case offsetof(struct user32, regs.rs):                          \
1083                 *val = get_segment_reg(child,                           \
1084                                        offsetof(struct user_regs_struct, rs)); \
1085                 break
1086
1087 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1088 {
1089         struct pt_regs *regs = task_pt_regs(child);
1090
1091         switch (regno) {
1092
1093         SEG32(ds);
1094         SEG32(es);
1095         SEG32(fs);
1096         SEG32(gs);
1097
1098         R32(cs, cs);
1099         R32(ss, ss);
1100         R32(ebx, bx);
1101         R32(ecx, cx);
1102         R32(edx, dx);
1103         R32(edi, di);
1104         R32(esi, si);
1105         R32(ebp, bp);
1106         R32(eax, ax);
1107         R32(orig_eax, orig_ax);
1108         R32(eip, ip);
1109         R32(esp, sp);
1110
1111         case offsetof(struct user32, regs.eflags):
1112                 *val = get_flags(child);
1113                 break;
1114
1115         case offsetof(struct user32, u_debugreg[0]) ...
1116                 offsetof(struct user32, u_debugreg[7]):
1117                 regno -= offsetof(struct user32, u_debugreg[0]);
1118                 *val = ptrace_get_debugreg(child, regno / 4);
1119                 break;
1120
1121         default:
1122                 if (regno > sizeof(struct user32) || (regno & 3))
1123                         return -EIO;
1124
1125                 /*
1126                  * Other dummy fields in the virtual user structure
1127                  * are ignored
1128                  */
1129                 *val = 0;
1130                 break;
1131         }
1132         return 0;
1133 }
1134
1135 #undef R32
1136 #undef SEG32
1137
1138 static int genregs32_get(struct task_struct *target,
1139                          const struct user_regset *regset,
1140                          unsigned int pos, unsigned int count,
1141                          void *kbuf, void __user *ubuf)
1142 {
1143         if (kbuf) {
1144                 compat_ulong_t *k = kbuf;
1145                 while (count > 0) {
1146                         getreg32(target, pos, k++);
1147                         count -= sizeof(*k);
1148                         pos += sizeof(*k);
1149                 }
1150         } else {
1151                 compat_ulong_t __user *u = ubuf;
1152                 while (count > 0) {
1153                         compat_ulong_t word;
1154                         getreg32(target, pos, &word);
1155                         if (__put_user(word, u++))
1156                                 return -EFAULT;
1157                         count -= sizeof(*u);
1158                         pos += sizeof(*u);
1159                 }
1160         }
1161
1162         return 0;
1163 }
1164
1165 static int genregs32_set(struct task_struct *target,
1166                          const struct user_regset *regset,
1167                          unsigned int pos, unsigned int count,
1168                          const void *kbuf, const void __user *ubuf)
1169 {
1170         int ret = 0;
1171         if (kbuf) {
1172                 const compat_ulong_t *k = kbuf;
1173                 while (count > 0 && !ret) {
1174                         ret = putreg32(target, pos, *k++);
1175                         count -= sizeof(*k);
1176                         pos += sizeof(*k);
1177                 }
1178         } else {
1179                 const compat_ulong_t __user *u = ubuf;
1180                 while (count > 0 && !ret) {
1181                         compat_ulong_t word;
1182                         ret = __get_user(word, u++);
1183                         if (ret)
1184                                 break;
1185                         ret = putreg32(target, pos, word);
1186                         count -= sizeof(*u);
1187                         pos += sizeof(*u);
1188                 }
1189         }
1190         return ret;
1191 }
1192
1193 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1194                         compat_ulong_t caddr, compat_ulong_t cdata)
1195 {
1196         unsigned long addr = caddr;
1197         unsigned long data = cdata;
1198         void __user *datap = compat_ptr(data);
1199         int ret;
1200         __u32 val;
1201
1202         switch (request) {
1203         case PTRACE_PEEKUSR:
1204                 ret = getreg32(child, addr, &val);
1205                 if (ret == 0)
1206                         ret = put_user(val, (__u32 __user *)datap);
1207                 break;
1208
1209         case PTRACE_POKEUSR:
1210                 ret = putreg32(child, addr, data);
1211                 break;
1212
1213         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1214                 return copy_regset_to_user(child, &user_x86_32_view,
1215                                            REGSET_GENERAL,
1216                                            0, sizeof(struct user_regs_struct32),
1217                                            datap);
1218
1219         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1220                 return copy_regset_from_user(child, &user_x86_32_view,
1221                                              REGSET_GENERAL, 0,
1222                                              sizeof(struct user_regs_struct32),
1223                                              datap);
1224
1225         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1226                 return copy_regset_to_user(child, &user_x86_32_view,
1227                                            REGSET_FP, 0,
1228                                            sizeof(struct user_i387_ia32_struct),
1229                                            datap);
1230
1231         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1232                 return copy_regset_from_user(
1233                         child, &user_x86_32_view, REGSET_FP,
1234                         0, sizeof(struct user_i387_ia32_struct), datap);
1235
1236         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1237                 return copy_regset_to_user(child, &user_x86_32_view,
1238                                            REGSET_XFP, 0,
1239                                            sizeof(struct user32_fxsr_struct),
1240                                            datap);
1241
1242         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1243                 return copy_regset_from_user(child, &user_x86_32_view,
1244                                              REGSET_XFP, 0,
1245                                              sizeof(struct user32_fxsr_struct),
1246                                              datap);
1247
1248         case PTRACE_GET_THREAD_AREA:
1249         case PTRACE_SET_THREAD_AREA:
1250 #ifdef CONFIG_X86_PTRACE_BTS
1251         case PTRACE_BTS_CONFIG:
1252         case PTRACE_BTS_STATUS:
1253         case PTRACE_BTS_SIZE:
1254         case PTRACE_BTS_GET:
1255         case PTRACE_BTS_CLEAR:
1256         case PTRACE_BTS_DRAIN:
1257 #endif /* CONFIG_X86_PTRACE_BTS */
1258                 return arch_ptrace(child, request, addr, data);
1259
1260         default:
1261                 return compat_ptrace_request(child, request, addr, data);
1262         }
1263
1264         return ret;
1265 }
1266
1267 #endif  /* CONFIG_IA32_EMULATION */
1268
1269 #ifdef CONFIG_X86_64
1270
1271 static const struct user_regset x86_64_regsets[] = {
1272         [REGSET_GENERAL] = {
1273                 .core_note_type = NT_PRSTATUS,
1274                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1275                 .size = sizeof(long), .align = sizeof(long),
1276                 .get = genregs_get, .set = genregs_set
1277         },
1278         [REGSET_FP] = {
1279                 .core_note_type = NT_PRFPREG,
1280                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1281                 .size = sizeof(long), .align = sizeof(long),
1282                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1283         },
1284         [REGSET_IOPERM64] = {
1285                 .core_note_type = NT_386_IOPERM,
1286                 .n = IO_BITMAP_LONGS,
1287                 .size = sizeof(long), .align = sizeof(long),
1288                 .active = ioperm_active, .get = ioperm_get
1289         },
1290 };
1291
1292 static const struct user_regset_view user_x86_64_view = {
1293         .name = "x86_64", .e_machine = EM_X86_64,
1294         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1295 };
1296
1297 #else  /* CONFIG_X86_32 */
1298
1299 #define user_regs_struct32      user_regs_struct
1300 #define genregs32_get           genregs_get
1301 #define genregs32_set           genregs_set
1302
1303 #define user_i387_ia32_struct   user_i387_struct
1304 #define user32_fxsr_struct      user_fxsr_struct
1305
1306 #endif  /* CONFIG_X86_64 */
1307
1308 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1309 static const struct user_regset x86_32_regsets[] = {
1310         [REGSET_GENERAL] = {
1311                 .core_note_type = NT_PRSTATUS,
1312                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1313                 .size = sizeof(u32), .align = sizeof(u32),
1314                 .get = genregs32_get, .set = genregs32_set
1315         },
1316         [REGSET_FP] = {
1317                 .core_note_type = NT_PRFPREG,
1318                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1319                 .size = sizeof(u32), .align = sizeof(u32),
1320                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1321         },
1322         [REGSET_XFP] = {
1323                 .core_note_type = NT_PRXFPREG,
1324                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1325                 .size = sizeof(u32), .align = sizeof(u32),
1326                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1327         },
1328         [REGSET_TLS] = {
1329                 .core_note_type = NT_386_TLS,
1330                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1331                 .size = sizeof(struct user_desc),
1332                 .align = sizeof(struct user_desc),
1333                 .active = regset_tls_active,
1334                 .get = regset_tls_get, .set = regset_tls_set
1335         },
1336         [REGSET_IOPERM32] = {
1337                 .core_note_type = NT_386_IOPERM,
1338                 .n = IO_BITMAP_BYTES / sizeof(u32),
1339                 .size = sizeof(u32), .align = sizeof(u32),
1340                 .active = ioperm_active, .get = ioperm_get
1341         },
1342 };
1343
1344 static const struct user_regset_view user_x86_32_view = {
1345         .name = "i386", .e_machine = EM_386,
1346         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1347 };
1348 #endif
1349
1350 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1351 {
1352 #ifdef CONFIG_IA32_EMULATION
1353         if (test_tsk_thread_flag(task, TIF_IA32))
1354 #endif
1355 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1356                 return &user_x86_32_view;
1357 #endif
1358 #ifdef CONFIG_X86_64
1359         return &user_x86_64_view;
1360 #endif
1361 }
1362
1363 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1364                                          int error_code, int si_code)
1365 {
1366         struct siginfo info;
1367
1368         tsk->thread.trap_no = 1;
1369         tsk->thread.error_code = error_code;
1370
1371         memset(&info, 0, sizeof(info));
1372         info.si_signo = SIGTRAP;
1373         info.si_code = si_code;
1374
1375         /* User-mode ip? */
1376         info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
1377
1378         /* Send us the fake SIGTRAP */
1379         force_sig_info(SIGTRAP, &info, tsk);
1380 }
1381
1382
1383 #ifdef CONFIG_X86_32
1384 # define IS_IA32        1
1385 #elif defined CONFIG_IA32_EMULATION
1386 # define IS_IA32        is_compat_task()
1387 #else
1388 # define IS_IA32        0
1389 #endif
1390
1391 /*
1392  * We must return the syscall number to actually look up in the table.
1393  * This can be -1L to skip running any syscall at all.
1394  */
1395 asmregparm long syscall_trace_enter(struct pt_regs *regs)
1396 {
1397         long ret = 0;
1398
1399         /*
1400          * If we stepped into a sysenter/syscall insn, it trapped in
1401          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1402          * If user-mode had set TF itself, then it's still clear from
1403          * do_debug() and we need to set it again to restore the user
1404          * state.  If we entered on the slow path, TF was already set.
1405          */
1406         if (test_thread_flag(TIF_SINGLESTEP))
1407                 regs->flags |= X86_EFLAGS_TF;
1408
1409         /* do the secure computing check first */
1410         secure_computing(regs->orig_ax);
1411
1412         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1413                 ret = -1L;
1414
1415         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1416             tracehook_report_syscall_entry(regs))
1417                 ret = -1L;
1418
1419         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
1420                 ftrace_syscall_enter(regs);
1421
1422         if (unlikely(current->audit_context)) {
1423                 if (IS_IA32)
1424                         audit_syscall_entry(AUDIT_ARCH_I386,
1425                                             regs->orig_ax,
1426                                             regs->bx, regs->cx,
1427                                             regs->dx, regs->si);
1428 #ifdef CONFIG_X86_64
1429                 else
1430                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1431                                             regs->orig_ax,
1432                                             regs->di, regs->si,
1433                                             regs->dx, regs->r10);
1434 #endif
1435         }
1436
1437         return ret ?: regs->orig_ax;
1438 }
1439
1440 asmregparm void syscall_trace_leave(struct pt_regs *regs)
1441 {
1442         if (unlikely(current->audit_context))
1443                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1444
1445         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
1446                 ftrace_syscall_exit(regs);
1447
1448         if (test_thread_flag(TIF_SYSCALL_TRACE))
1449                 tracehook_report_syscall_exit(regs, 0);
1450
1451         /*
1452          * If TIF_SYSCALL_EMU is set, we only get here because of
1453          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1454          * We already reported this syscall instruction in
1455          * syscall_trace_enter(), so don't do any more now.
1456          */
1457         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1458                 return;
1459
1460         /*
1461          * If we are single-stepping, synthesize a trap to follow the
1462          * system call instruction.
1463          */
1464         if (test_thread_flag(TIF_SINGLESTEP) &&
1465             tracehook_consider_fatal_signal(current, SIGTRAP, SIG_DFL))
1466                 send_sigtrap(current, regs, 0, TRAP_BRKPT);
1467 }