Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzi...
[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 <trace/syscall.h>
38
39 #include "tls.h"
40
41 enum x86_regset {
42         REGSET_GENERAL,
43         REGSET_FP,
44         REGSET_XFP,
45         REGSET_IOPERM64 = REGSET_XFP,
46         REGSET_TLS,
47         REGSET_IOPERM32,
48 };
49
50 /*
51  * does not yet catch signals sent when the child dies.
52  * in exit.c or in signal.c.
53  */
54
55 /*
56  * Determines which flags the user has access to [1 = access, 0 = no access].
57  */
58 #define FLAG_MASK_32            ((unsigned long)                        \
59                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
60                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
61                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
62                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
63                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
64
65 /*
66  * Determines whether a value may be installed in a segment register.
67  */
68 static inline bool invalid_selector(u16 value)
69 {
70         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
71 }
72
73 #ifdef CONFIG_X86_32
74
75 #define FLAG_MASK               FLAG_MASK_32
76
77 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
78 {
79         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
80         return &regs->bx + (regno >> 2);
81 }
82
83 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
84 {
85         /*
86          * Returning the value truncates it to 16 bits.
87          */
88         unsigned int retval;
89         if (offset != offsetof(struct user_regs_struct, gs))
90                 retval = *pt_regs_access(task_pt_regs(task), offset);
91         else {
92                 if (task == current)
93                         retval = get_user_gs(task_pt_regs(task));
94                 else
95                         retval = task_user_gs(task);
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                 if (task == current)
130                         set_user_gs(task_pt_regs(task), value);
131                 else
132                         task_user_gs(task) = value;
133         }
134
135         return 0;
136 }
137
138 static unsigned long debugreg_addr_limit(struct task_struct *task)
139 {
140         return TASK_SIZE - 3;
141 }
142
143 #else  /* CONFIG_X86_64 */
144
145 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
146
147 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
148 {
149         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
150         return &regs->r15 + (offset / sizeof(regs->r15));
151 }
152
153 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
154 {
155         /*
156          * Returning the value truncates it to 16 bits.
157          */
158         unsigned int seg;
159
160         switch (offset) {
161         case offsetof(struct user_regs_struct, fs):
162                 if (task == current) {
163                         /* Older gas can't assemble movq %?s,%r?? */
164                         asm("movl %%fs,%0" : "=r" (seg));
165                         return seg;
166                 }
167                 return task->thread.fsindex;
168         case offsetof(struct user_regs_struct, gs):
169                 if (task == current) {
170                         asm("movl %%gs,%0" : "=r" (seg));
171                         return seg;
172                 }
173                 return task->thread.gsindex;
174         case offsetof(struct user_regs_struct, ds):
175                 if (task == current) {
176                         asm("movl %%ds,%0" : "=r" (seg));
177                         return seg;
178                 }
179                 return task->thread.ds;
180         case offsetof(struct user_regs_struct, es):
181                 if (task == current) {
182                         asm("movl %%es,%0" : "=r" (seg));
183                         return seg;
184                 }
185                 return task->thread.es;
186
187         case offsetof(struct user_regs_struct, cs):
188         case offsetof(struct user_regs_struct, ss):
189                 break;
190         }
191         return *pt_regs_access(task_pt_regs(task), offset);
192 }
193
194 static int set_segment_reg(struct task_struct *task,
195                            unsigned long offset, u16 value)
196 {
197         /*
198          * The value argument was already truncated to 16 bits.
199          */
200         if (invalid_selector(value))
201                 return -EIO;
202
203         switch (offset) {
204         case offsetof(struct user_regs_struct,fs):
205                 /*
206                  * If this is setting fs as for normal 64-bit use but
207                  * setting fs_base has implicitly changed it, leave it.
208                  */
209                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
210                      task->thread.fs != 0) ||
211                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
212                      task->thread.fs == 0))
213                         break;
214                 task->thread.fsindex = value;
215                 if (task == current)
216                         loadsegment(fs, task->thread.fsindex);
217                 break;
218         case offsetof(struct user_regs_struct,gs):
219                 /*
220                  * If this is setting gs as for normal 64-bit use but
221                  * setting gs_base has implicitly changed it, leave it.
222                  */
223                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
224                      task->thread.gs != 0) ||
225                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
226                      task->thread.gs == 0))
227                         break;
228                 task->thread.gsindex = value;
229                 if (task == current)
230                         load_gs_index(task->thread.gsindex);
231                 break;
232         case offsetof(struct user_regs_struct,ds):
233                 task->thread.ds = value;
234                 if (task == current)
235                         loadsegment(ds, task->thread.ds);
236                 break;
237         case offsetof(struct user_regs_struct,es):
238                 task->thread.es = value;
239                 if (task == current)
240                         loadsegment(es, task->thread.es);
241                 break;
242
243                 /*
244                  * Can't actually change these in 64-bit mode.
245                  */
246         case offsetof(struct user_regs_struct,cs):
247                 if (unlikely(value == 0))
248                         return -EIO;
249 #ifdef CONFIG_IA32_EMULATION
250                 if (test_tsk_thread_flag(task, TIF_IA32))
251                         task_pt_regs(task)->cs = value;
252 #endif
253                 break;
254         case offsetof(struct user_regs_struct,ss):
255                 if (unlikely(value == 0))
256                         return -EIO;
257 #ifdef CONFIG_IA32_EMULATION
258                 if (test_tsk_thread_flag(task, TIF_IA32))
259                         task_pt_regs(task)->ss = value;
260 #endif
261                 break;
262         }
263
264         return 0;
265 }
266
267 static unsigned long debugreg_addr_limit(struct task_struct *task)
268 {
269 #ifdef CONFIG_IA32_EMULATION
270         if (test_tsk_thread_flag(task, TIF_IA32))
271                 return IA32_PAGE_OFFSET - 3;
272 #endif
273         return TASK_SIZE_MAX - 7;
274 }
275
276 #endif  /* CONFIG_X86_32 */
277
278 static unsigned long get_flags(struct task_struct *task)
279 {
280         unsigned long retval = task_pt_regs(task)->flags;
281
282         /*
283          * If the debugger set TF, hide it from the readout.
284          */
285         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
286                 retval &= ~X86_EFLAGS_TF;
287
288         return retval;
289 }
290
291 static int set_flags(struct task_struct *task, unsigned long value)
292 {
293         struct pt_regs *regs = task_pt_regs(task);
294
295         /*
296          * If the user value contains TF, mark that
297          * it was not "us" (the debugger) that set it.
298          * If not, make sure it stays set if we had.
299          */
300         if (value & X86_EFLAGS_TF)
301                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
302         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
303                 value |= X86_EFLAGS_TF;
304
305         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
306
307         return 0;
308 }
309
310 static int putreg(struct task_struct *child,
311                   unsigned long offset, unsigned long value)
312 {
313         switch (offset) {
314         case offsetof(struct user_regs_struct, cs):
315         case offsetof(struct user_regs_struct, ds):
316         case offsetof(struct user_regs_struct, es):
317         case offsetof(struct user_regs_struct, fs):
318         case offsetof(struct user_regs_struct, gs):
319         case offsetof(struct user_regs_struct, ss):
320                 return set_segment_reg(child, offset, value);
321
322         case offsetof(struct user_regs_struct, flags):
323                 return set_flags(child, value);
324
325 #ifdef CONFIG_X86_64
326         /*
327          * Orig_ax is really just a flag with small positive and
328          * negative values, so make sure to always sign-extend it
329          * from 32 bits so that it works correctly regardless of
330          * whether we come from a 32-bit environment or not.
331          */
332         case offsetof(struct user_regs_struct, orig_ax):
333                 value = (long) (s32) value;
334                 break;
335
336         case offsetof(struct user_regs_struct,fs_base):
337                 if (value >= TASK_SIZE_OF(child))
338                         return -EIO;
339                 /*
340                  * When changing the segment base, use do_arch_prctl
341                  * to set either thread.fs or thread.fsindex and the
342                  * corresponding GDT slot.
343                  */
344                 if (child->thread.fs != value)
345                         return do_arch_prctl(child, ARCH_SET_FS, value);
346                 return 0;
347         case offsetof(struct user_regs_struct,gs_base):
348                 /*
349                  * Exactly the same here as the %fs handling above.
350                  */
351                 if (value >= TASK_SIZE_OF(child))
352                         return -EIO;
353                 if (child->thread.gs != value)
354                         return do_arch_prctl(child, ARCH_SET_GS, value);
355                 return 0;
356 #endif
357         }
358
359         *pt_regs_access(task_pt_regs(child), offset) = value;
360         return 0;
361 }
362
363 static unsigned long getreg(struct task_struct *task, unsigned long offset)
364 {
365         switch (offset) {
366         case offsetof(struct user_regs_struct, cs):
367         case offsetof(struct user_regs_struct, ds):
368         case offsetof(struct user_regs_struct, es):
369         case offsetof(struct user_regs_struct, fs):
370         case offsetof(struct user_regs_struct, gs):
371         case offsetof(struct user_regs_struct, ss):
372                 return get_segment_reg(task, offset);
373
374         case offsetof(struct user_regs_struct, flags):
375                 return get_flags(task);
376
377 #ifdef CONFIG_X86_64
378         case offsetof(struct user_regs_struct, fs_base): {
379                 /*
380                  * do_arch_prctl may have used a GDT slot instead of
381                  * the MSR.  To userland, it appears the same either
382                  * way, except the %fs segment selector might not be 0.
383                  */
384                 unsigned int seg = task->thread.fsindex;
385                 if (task->thread.fs != 0)
386                         return task->thread.fs;
387                 if (task == current)
388                         asm("movl %%fs,%0" : "=r" (seg));
389                 if (seg != FS_TLS_SEL)
390                         return 0;
391                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
392         }
393         case offsetof(struct user_regs_struct, gs_base): {
394                 /*
395                  * Exactly the same here as the %fs handling above.
396                  */
397                 unsigned int seg = task->thread.gsindex;
398                 if (task->thread.gs != 0)
399                         return task->thread.gs;
400                 if (task == current)
401                         asm("movl %%gs,%0" : "=r" (seg));
402                 if (seg != GS_TLS_SEL)
403                         return 0;
404                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
405         }
406 #endif
407         }
408
409         return *pt_regs_access(task_pt_regs(task), offset);
410 }
411
412 static int genregs_get(struct task_struct *target,
413                        const struct user_regset *regset,
414                        unsigned int pos, unsigned int count,
415                        void *kbuf, void __user *ubuf)
416 {
417         if (kbuf) {
418                 unsigned long *k = kbuf;
419                 while (count > 0) {
420                         *k++ = getreg(target, pos);
421                         count -= sizeof(*k);
422                         pos += sizeof(*k);
423                 }
424         } else {
425                 unsigned long __user *u = ubuf;
426                 while (count > 0) {
427                         if (__put_user(getreg(target, pos), u++))
428                                 return -EFAULT;
429                         count -= sizeof(*u);
430                         pos += sizeof(*u);
431                 }
432         }
433
434         return 0;
435 }
436
437 static int genregs_set(struct task_struct *target,
438                        const struct user_regset *regset,
439                        unsigned int pos, unsigned int count,
440                        const void *kbuf, const void __user *ubuf)
441 {
442         int ret = 0;
443         if (kbuf) {
444                 const unsigned long *k = kbuf;
445                 while (count > 0 && !ret) {
446                         ret = putreg(target, pos, *k++);
447                         count -= sizeof(*k);
448                         pos += sizeof(*k);
449                 }
450         } else {
451                 const unsigned long  __user *u = ubuf;
452                 while (count > 0 && !ret) {
453                         unsigned long word;
454                         ret = __get_user(word, u++);
455                         if (ret)
456                                 break;
457                         ret = putreg(target, pos, word);
458                         count -= sizeof(*u);
459                         pos += sizeof(*u);
460                 }
461         }
462         return ret;
463 }
464
465 /*
466  * This function is trivial and will be inlined by the compiler.
467  * Having it separates the implementation details of debug
468  * registers from the interface details of ptrace.
469  */
470 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
471 {
472         switch (n) {
473         case 0:         return child->thread.debugreg0;
474         case 1:         return child->thread.debugreg1;
475         case 2:         return child->thread.debugreg2;
476         case 3:         return child->thread.debugreg3;
477         case 6:         return child->thread.debugreg6;
478         case 7:         return child->thread.debugreg7;
479         }
480         return 0;
481 }
482
483 static int ptrace_set_debugreg(struct task_struct *child,
484                                int n, unsigned long data)
485 {
486         int i;
487
488         if (unlikely(n == 4 || n == 5))
489                 return -EIO;
490
491         if (n < 4 && unlikely(data >= debugreg_addr_limit(child)))
492                 return -EIO;
493
494         switch (n) {
495         case 0:         child->thread.debugreg0 = data; break;
496         case 1:         child->thread.debugreg1 = data; break;
497         case 2:         child->thread.debugreg2 = data; break;
498         case 3:         child->thread.debugreg3 = data; break;
499
500         case 6:
501                 if ((data & ~0xffffffffUL) != 0)
502                         return -EIO;
503                 child->thread.debugreg6 = data;
504                 break;
505
506         case 7:
507                 /*
508                  * Sanity-check data. Take one half-byte at once with
509                  * check = (val >> (16 + 4*i)) & 0xf. It contains the
510                  * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
511                  * 2 and 3 are LENi. Given a list of invalid values,
512                  * we do mask |= 1 << invalid_value, so that
513                  * (mask >> check) & 1 is a correct test for invalid
514                  * values.
515                  *
516                  * R/Wi contains the type of the breakpoint /
517                  * watchpoint, LENi contains the length of the watched
518                  * data in the watchpoint case.
519                  *
520                  * The invalid values are:
521                  * - LENi == 0x10 (undefined), so mask |= 0x0f00.       [32-bit]
522                  * - R/Wi == 0x10 (break on I/O reads or writes), so
523                  *   mask |= 0x4444.
524                  * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
525                  *   0x1110.
526                  *
527                  * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
528                  *
529                  * See the Intel Manual "System Programming Guide",
530                  * 15.2.4
531                  *
532                  * Note that LENi == 0x10 is defined on x86_64 in long
533                  * mode (i.e. even for 32-bit userspace software, but
534                  * 64-bit kernel), so the x86_64 mask value is 0x5454.
535                  * See the AMD manual no. 24593 (AMD64 System Programming)
536                  */
537 #ifdef CONFIG_X86_32
538 #define DR7_MASK        0x5f54
539 #else
540 #define DR7_MASK        0x5554
541 #endif
542                 data &= ~DR_CONTROL_RESERVED;
543                 for (i = 0; i < 4; i++)
544                         if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1)
545                                 return -EIO;
546                 child->thread.debugreg7 = data;
547                 if (data)
548                         set_tsk_thread_flag(child, TIF_DEBUG);
549                 else
550                         clear_tsk_thread_flag(child, TIF_DEBUG);
551                 break;
552         }
553
554         return 0;
555 }
556
557 /*
558  * These access the current or another (stopped) task's io permission
559  * bitmap for debugging or core dump.
560  */
561 static int ioperm_active(struct task_struct *target,
562                          const struct user_regset *regset)
563 {
564         return target->thread.io_bitmap_max / regset->size;
565 }
566
567 static int ioperm_get(struct task_struct *target,
568                       const struct user_regset *regset,
569                       unsigned int pos, unsigned int count,
570                       void *kbuf, void __user *ubuf)
571 {
572         if (!target->thread.io_bitmap_ptr)
573                 return -ENXIO;
574
575         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
576                                    target->thread.io_bitmap_ptr,
577                                    0, IO_BITMAP_BYTES);
578 }
579
580 #ifdef CONFIG_X86_PTRACE_BTS
581 static int ptrace_bts_read_record(struct task_struct *child, size_t index,
582                                   struct bts_struct __user *out)
583 {
584         const struct bts_trace *trace;
585         struct bts_struct bts;
586         const unsigned char *at;
587         int error;
588
589         trace = ds_read_bts(child->bts);
590         if (!trace)
591                 return -EPERM;
592
593         at = trace->ds.top - ((index + 1) * trace->ds.size);
594         if ((void *)at < trace->ds.begin)
595                 at += (trace->ds.n * trace->ds.size);
596
597         if (!trace->read)
598                 return -EOPNOTSUPP;
599
600         error = trace->read(child->bts, at, &bts);
601         if (error < 0)
602                 return error;
603
604         if (copy_to_user(out, &bts, sizeof(bts)))
605                 return -EFAULT;
606
607         return sizeof(bts);
608 }
609
610 static int ptrace_bts_drain(struct task_struct *child,
611                             long size,
612                             struct bts_struct __user *out)
613 {
614         const struct bts_trace *trace;
615         const unsigned char *at;
616         int error, drained = 0;
617
618         trace = ds_read_bts(child->bts);
619         if (!trace)
620                 return -EPERM;
621
622         if (!trace->read)
623                 return -EOPNOTSUPP;
624
625         if (size < (trace->ds.top - trace->ds.begin))
626                 return -EIO;
627
628         for (at = trace->ds.begin; (void *)at < trace->ds.top;
629              out++, drained++, at += trace->ds.size) {
630                 struct bts_struct bts;
631                 int error;
632
633                 error = trace->read(child->bts, at, &bts);
634                 if (error < 0)
635                         return error;
636
637                 if (copy_to_user(out, &bts, sizeof(bts)))
638                         return -EFAULT;
639         }
640
641         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
642
643         error = ds_reset_bts(child->bts);
644         if (error < 0)
645                 return error;
646
647         return drained;
648 }
649
650 static int ptrace_bts_allocate_buffer(struct task_struct *child, size_t size)
651 {
652         child->bts_buffer = alloc_locked_buffer(size);
653         if (!child->bts_buffer)
654                 return -ENOMEM;
655
656         child->bts_size = size;
657
658         return 0;
659 }
660
661 static void ptrace_bts_free_buffer(struct task_struct *child)
662 {
663         free_locked_buffer(child->bts_buffer, child->bts_size);
664         child->bts_buffer = NULL;
665         child->bts_size = 0;
666 }
667
668 static int ptrace_bts_config(struct task_struct *child,
669                              long cfg_size,
670                              const struct ptrace_bts_config __user *ucfg)
671 {
672         struct ptrace_bts_config cfg;
673         unsigned int flags = 0;
674
675         if (cfg_size < sizeof(cfg))
676                 return -EIO;
677
678         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
679                 return -EFAULT;
680
681         if (child->bts) {
682                 ds_release_bts(child->bts);
683                 child->bts = NULL;
684         }
685
686         if (cfg.flags & PTRACE_BTS_O_SIGNAL) {
687                 if (!cfg.signal)
688                         return -EINVAL;
689
690                 child->thread.bts_ovfl_signal = cfg.signal;
691                 return -EOPNOTSUPP;
692         }
693
694         if ((cfg.flags & PTRACE_BTS_O_ALLOC) &&
695             (cfg.size != child->bts_size)) {
696                 int error;
697
698                 ptrace_bts_free_buffer(child);
699
700                 error = ptrace_bts_allocate_buffer(child, cfg.size);
701                 if (error < 0)
702                         return error;
703         }
704
705         if (cfg.flags & PTRACE_BTS_O_TRACE)
706                 flags |= BTS_USER;
707
708         if (cfg.flags & PTRACE_BTS_O_SCHED)
709                 flags |= BTS_TIMESTAMPS;
710
711         child->bts = ds_request_bts(child, child->bts_buffer, child->bts_size,
712                                     /* ovfl = */ NULL, /* th = */ (size_t)-1,
713                                     flags);
714         if (IS_ERR(child->bts)) {
715                 int error = PTR_ERR(child->bts);
716
717                 ptrace_bts_free_buffer(child);
718                 child->bts = NULL;
719
720                 return error;
721         }
722
723         return sizeof(cfg);
724 }
725
726 static int ptrace_bts_status(struct task_struct *child,
727                              long cfg_size,
728                              struct ptrace_bts_config __user *ucfg)
729 {
730         const struct bts_trace *trace;
731         struct ptrace_bts_config cfg;
732
733         if (cfg_size < sizeof(cfg))
734                 return -EIO;
735
736         trace = ds_read_bts(child->bts);
737         if (!trace)
738                 return -EPERM;
739
740         memset(&cfg, 0, sizeof(cfg));
741         cfg.size = trace->ds.end - trace->ds.begin;
742         cfg.signal = child->thread.bts_ovfl_signal;
743         cfg.bts_size = sizeof(struct bts_struct);
744
745         if (cfg.signal)
746                 cfg.flags |= PTRACE_BTS_O_SIGNAL;
747
748         if (trace->ds.flags & BTS_USER)
749                 cfg.flags |= PTRACE_BTS_O_TRACE;
750
751         if (trace->ds.flags & BTS_TIMESTAMPS)
752                 cfg.flags |= PTRACE_BTS_O_SCHED;
753
754         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
755                 return -EFAULT;
756
757         return sizeof(cfg);
758 }
759
760 static int ptrace_bts_clear(struct task_struct *child)
761 {
762         const struct bts_trace *trace;
763
764         trace = ds_read_bts(child->bts);
765         if (!trace)
766                 return -EPERM;
767
768         memset(trace->ds.begin, 0, trace->ds.n * trace->ds.size);
769
770         return ds_reset_bts(child->bts);
771 }
772
773 static int ptrace_bts_size(struct task_struct *child)
774 {
775         const struct bts_trace *trace;
776
777         trace = ds_read_bts(child->bts);
778         if (!trace)
779                 return -EPERM;
780
781         return (trace->ds.top - trace->ds.begin) / trace->ds.size;
782 }
783
784 static void ptrace_bts_fork(struct task_struct *tsk)
785 {
786         tsk->bts = NULL;
787         tsk->bts_buffer = NULL;
788         tsk->bts_size = 0;
789         tsk->thread.bts_ovfl_signal = 0;
790 }
791
792 static void ptrace_bts_untrace(struct task_struct *child)
793 {
794         if (unlikely(child->bts)) {
795                 ds_release_bts(child->bts);
796                 child->bts = NULL;
797
798                 /* We cannot update total_vm and locked_vm since
799                    child's mm is already gone. But we can reclaim the
800                    memory. */
801                 kfree(child->bts_buffer);
802                 child->bts_buffer = NULL;
803                 child->bts_size = 0;
804         }
805 }
806
807 static void ptrace_bts_detach(struct task_struct *child)
808 {
809         /*
810          * Ptrace_detach() races with ptrace_untrace() in case
811          * the child dies and is reaped by another thread.
812          *
813          * We only do the memory accounting at this point and
814          * leave the buffer deallocation and the bts tracer
815          * release to ptrace_bts_untrace() which will be called
816          * later on with tasklist_lock held.
817          */
818         release_locked_buffer(child->bts_buffer, child->bts_size);
819 }
820 #else
821 static inline void ptrace_bts_fork(struct task_struct *tsk) {}
822 static inline void ptrace_bts_detach(struct task_struct *child) {}
823 static inline void ptrace_bts_untrace(struct task_struct *child) {}
824 #endif /* CONFIG_X86_PTRACE_BTS */
825
826 void x86_ptrace_fork(struct task_struct *child, unsigned long clone_flags)
827 {
828         ptrace_bts_fork(child);
829 }
830
831 void x86_ptrace_untrace(struct task_struct *child)
832 {
833         ptrace_bts_untrace(child);
834 }
835
836 /*
837  * Called by kernel/ptrace.c when detaching..
838  *
839  * Make sure the single step bit is not set.
840  */
841 void ptrace_disable(struct task_struct *child)
842 {
843         user_disable_single_step(child);
844 #ifdef TIF_SYSCALL_EMU
845         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
846 #endif
847         ptrace_bts_detach(child);
848 }
849
850 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
851 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
852 #endif
853
854 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
855 {
856         int ret;
857         unsigned long __user *datap = (unsigned long __user *)data;
858
859         switch (request) {
860         /* read the word at location addr in the USER area. */
861         case PTRACE_PEEKUSR: {
862                 unsigned long tmp;
863
864                 ret = -EIO;
865                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
866                     addr >= sizeof(struct user))
867                         break;
868
869                 tmp = 0;  /* Default return condition */
870                 if (addr < sizeof(struct user_regs_struct))
871                         tmp = getreg(child, addr);
872                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
873                          addr <= offsetof(struct user, u_debugreg[7])) {
874                         addr -= offsetof(struct user, u_debugreg[0]);
875                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
876                 }
877                 ret = put_user(tmp, datap);
878                 break;
879         }
880
881         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
882                 ret = -EIO;
883                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
884                     addr >= sizeof(struct user))
885                         break;
886
887                 if (addr < sizeof(struct user_regs_struct))
888                         ret = putreg(child, addr, data);
889                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
890                          addr <= offsetof(struct user, u_debugreg[7])) {
891                         addr -= offsetof(struct user, u_debugreg[0]);
892                         ret = ptrace_set_debugreg(child,
893                                                   addr / sizeof(data), data);
894                 }
895                 break;
896
897         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
898                 return copy_regset_to_user(child,
899                                            task_user_regset_view(current),
900                                            REGSET_GENERAL,
901                                            0, sizeof(struct user_regs_struct),
902                                            datap);
903
904         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
905                 return copy_regset_from_user(child,
906                                              task_user_regset_view(current),
907                                              REGSET_GENERAL,
908                                              0, sizeof(struct user_regs_struct),
909                                              datap);
910
911         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
912                 return copy_regset_to_user(child,
913                                            task_user_regset_view(current),
914                                            REGSET_FP,
915                                            0, sizeof(struct user_i387_struct),
916                                            datap);
917
918         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
919                 return copy_regset_from_user(child,
920                                              task_user_regset_view(current),
921                                              REGSET_FP,
922                                              0, sizeof(struct user_i387_struct),
923                                              datap);
924
925 #ifdef CONFIG_X86_32
926         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
927                 return copy_regset_to_user(child, &user_x86_32_view,
928                                            REGSET_XFP,
929                                            0, sizeof(struct user_fxsr_struct),
930                                            datap) ? -EIO : 0;
931
932         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
933                 return copy_regset_from_user(child, &user_x86_32_view,
934                                              REGSET_XFP,
935                                              0, sizeof(struct user_fxsr_struct),
936                                              datap) ? -EIO : 0;
937 #endif
938
939 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
940         case PTRACE_GET_THREAD_AREA:
941                 if (addr < 0)
942                         return -EIO;
943                 ret = do_get_thread_area(child, addr,
944                                          (struct user_desc __user *) data);
945                 break;
946
947         case PTRACE_SET_THREAD_AREA:
948                 if (addr < 0)
949                         return -EIO;
950                 ret = do_set_thread_area(child, addr,
951                                          (struct user_desc __user *) data, 0);
952                 break;
953 #endif
954
955 #ifdef CONFIG_X86_64
956                 /* normal 64bit interface to access TLS data.
957                    Works just like arch_prctl, except that the arguments
958                    are reversed. */
959         case PTRACE_ARCH_PRCTL:
960                 ret = do_arch_prctl(child, data, addr);
961                 break;
962 #endif
963
964         /*
965          * These bits need more cooking - not enabled yet:
966          */
967 #ifdef CONFIG_X86_PTRACE_BTS
968         case PTRACE_BTS_CONFIG:
969                 ret = ptrace_bts_config
970                         (child, data, (struct ptrace_bts_config __user *)addr);
971                 break;
972
973         case PTRACE_BTS_STATUS:
974                 ret = ptrace_bts_status
975                         (child, data, (struct ptrace_bts_config __user *)addr);
976                 break;
977
978         case PTRACE_BTS_SIZE:
979                 ret = ptrace_bts_size(child);
980                 break;
981
982         case PTRACE_BTS_GET:
983                 ret = ptrace_bts_read_record
984                         (child, data, (struct bts_struct __user *) addr);
985                 break;
986
987         case PTRACE_BTS_CLEAR:
988                 ret = ptrace_bts_clear(child);
989                 break;
990
991         case PTRACE_BTS_DRAIN:
992                 ret = ptrace_bts_drain
993                         (child, data, (struct bts_struct __user *) addr);
994                 break;
995 #endif /* CONFIG_X86_PTRACE_BTS */
996
997         default:
998                 ret = ptrace_request(child, request, addr, data);
999                 break;
1000         }
1001
1002         return ret;
1003 }
1004
1005 #ifdef CONFIG_IA32_EMULATION
1006
1007 #include <linux/compat.h>
1008 #include <linux/syscalls.h>
1009 #include <asm/ia32.h>
1010 #include <asm/user32.h>
1011
1012 #define R32(l,q)                                                        \
1013         case offsetof(struct user32, regs.l):                           \
1014                 regs->q = value; break
1015
1016 #define SEG32(rs)                                                       \
1017         case offsetof(struct user32, regs.rs):                          \
1018                 return set_segment_reg(child,                           \
1019                                        offsetof(struct user_regs_struct, rs), \
1020                                        value);                          \
1021                 break
1022
1023 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
1024 {
1025         struct pt_regs *regs = task_pt_regs(child);
1026
1027         switch (regno) {
1028
1029         SEG32(cs);
1030         SEG32(ds);
1031         SEG32(es);
1032         SEG32(fs);
1033         SEG32(gs);
1034         SEG32(ss);
1035
1036         R32(ebx, bx);
1037         R32(ecx, cx);
1038         R32(edx, dx);
1039         R32(edi, di);
1040         R32(esi, si);
1041         R32(ebp, bp);
1042         R32(eax, ax);
1043         R32(eip, ip);
1044         R32(esp, sp);
1045
1046         case offsetof(struct user32, regs.orig_eax):
1047                 /*
1048                  * Sign-extend the value so that orig_eax = -1
1049                  * causes (long)orig_ax < 0 tests to fire correctly.
1050                  */
1051                 regs->orig_ax = (long) (s32) value;
1052                 break;
1053
1054         case offsetof(struct user32, regs.eflags):
1055                 return set_flags(child, value);
1056
1057         case offsetof(struct user32, u_debugreg[0]) ...
1058                 offsetof(struct user32, u_debugreg[7]):
1059                 regno -= offsetof(struct user32, u_debugreg[0]);
1060                 return ptrace_set_debugreg(child, regno / 4, value);
1061
1062         default:
1063                 if (regno > sizeof(struct user32) || (regno & 3))
1064                         return -EIO;
1065
1066                 /*
1067                  * Other dummy fields in the virtual user structure
1068                  * are ignored
1069                  */
1070                 break;
1071         }
1072         return 0;
1073 }
1074
1075 #undef R32
1076 #undef SEG32
1077
1078 #define R32(l,q)                                                        \
1079         case offsetof(struct user32, regs.l):                           \
1080                 *val = regs->q; break
1081
1082 #define SEG32(rs)                                                       \
1083         case offsetof(struct user32, regs.rs):                          \
1084                 *val = get_segment_reg(child,                           \
1085                                        offsetof(struct user_regs_struct, rs)); \
1086                 break
1087
1088 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1089 {
1090         struct pt_regs *regs = task_pt_regs(child);
1091
1092         switch (regno) {
1093
1094         SEG32(ds);
1095         SEG32(es);
1096         SEG32(fs);
1097         SEG32(gs);
1098
1099         R32(cs, cs);
1100         R32(ss, ss);
1101         R32(ebx, bx);
1102         R32(ecx, cx);
1103         R32(edx, dx);
1104         R32(edi, di);
1105         R32(esi, si);
1106         R32(ebp, bp);
1107         R32(eax, ax);
1108         R32(orig_eax, orig_ax);
1109         R32(eip, ip);
1110         R32(esp, sp);
1111
1112         case offsetof(struct user32, regs.eflags):
1113                 *val = get_flags(child);
1114                 break;
1115
1116         case offsetof(struct user32, u_debugreg[0]) ...
1117                 offsetof(struct user32, u_debugreg[7]):
1118                 regno -= offsetof(struct user32, u_debugreg[0]);
1119                 *val = ptrace_get_debugreg(child, regno / 4);
1120                 break;
1121
1122         default:
1123                 if (regno > sizeof(struct user32) || (regno & 3))
1124                         return -EIO;
1125
1126                 /*
1127                  * Other dummy fields in the virtual user structure
1128                  * are ignored
1129                  */
1130                 *val = 0;
1131                 break;
1132         }
1133         return 0;
1134 }
1135
1136 #undef R32
1137 #undef SEG32
1138
1139 static int genregs32_get(struct task_struct *target,
1140                          const struct user_regset *regset,
1141                          unsigned int pos, unsigned int count,
1142                          void *kbuf, void __user *ubuf)
1143 {
1144         if (kbuf) {
1145                 compat_ulong_t *k = kbuf;
1146                 while (count > 0) {
1147                         getreg32(target, pos, k++);
1148                         count -= sizeof(*k);
1149                         pos += sizeof(*k);
1150                 }
1151         } else {
1152                 compat_ulong_t __user *u = ubuf;
1153                 while (count > 0) {
1154                         compat_ulong_t word;
1155                         getreg32(target, pos, &word);
1156                         if (__put_user(word, u++))
1157                                 return -EFAULT;
1158                         count -= sizeof(*u);
1159                         pos += sizeof(*u);
1160                 }
1161         }
1162
1163         return 0;
1164 }
1165
1166 static int genregs32_set(struct task_struct *target,
1167                          const struct user_regset *regset,
1168                          unsigned int pos, unsigned int count,
1169                          const void *kbuf, const void __user *ubuf)
1170 {
1171         int ret = 0;
1172         if (kbuf) {
1173                 const compat_ulong_t *k = kbuf;
1174                 while (count > 0 && !ret) {
1175                         ret = putreg32(target, pos, *k++);
1176                         count -= sizeof(*k);
1177                         pos += sizeof(*k);
1178                 }
1179         } else {
1180                 const compat_ulong_t __user *u = ubuf;
1181                 while (count > 0 && !ret) {
1182                         compat_ulong_t word;
1183                         ret = __get_user(word, u++);
1184                         if (ret)
1185                                 break;
1186                         ret = putreg32(target, pos, word);
1187                         count -= sizeof(*u);
1188                         pos += sizeof(*u);
1189                 }
1190         }
1191         return ret;
1192 }
1193
1194 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1195                         compat_ulong_t caddr, compat_ulong_t cdata)
1196 {
1197         unsigned long addr = caddr;
1198         unsigned long data = cdata;
1199         void __user *datap = compat_ptr(data);
1200         int ret;
1201         __u32 val;
1202
1203         switch (request) {
1204         case PTRACE_PEEKUSR:
1205                 ret = getreg32(child, addr, &val);
1206                 if (ret == 0)
1207                         ret = put_user(val, (__u32 __user *)datap);
1208                 break;
1209
1210         case PTRACE_POKEUSR:
1211                 ret = putreg32(child, addr, data);
1212                 break;
1213
1214         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1215                 return copy_regset_to_user(child, &user_x86_32_view,
1216                                            REGSET_GENERAL,
1217                                            0, sizeof(struct user_regs_struct32),
1218                                            datap);
1219
1220         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1221                 return copy_regset_from_user(child, &user_x86_32_view,
1222                                              REGSET_GENERAL, 0,
1223                                              sizeof(struct user_regs_struct32),
1224                                              datap);
1225
1226         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1227                 return copy_regset_to_user(child, &user_x86_32_view,
1228                                            REGSET_FP, 0,
1229                                            sizeof(struct user_i387_ia32_struct),
1230                                            datap);
1231
1232         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1233                 return copy_regset_from_user(
1234                         child, &user_x86_32_view, REGSET_FP,
1235                         0, sizeof(struct user_i387_ia32_struct), datap);
1236
1237         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1238                 return copy_regset_to_user(child, &user_x86_32_view,
1239                                            REGSET_XFP, 0,
1240                                            sizeof(struct user32_fxsr_struct),
1241                                            datap);
1242
1243         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1244                 return copy_regset_from_user(child, &user_x86_32_view,
1245                                              REGSET_XFP, 0,
1246                                              sizeof(struct user32_fxsr_struct),
1247                                              datap);
1248
1249         case PTRACE_GET_THREAD_AREA:
1250         case PTRACE_SET_THREAD_AREA:
1251 #ifdef CONFIG_X86_PTRACE_BTS
1252         case PTRACE_BTS_CONFIG:
1253         case PTRACE_BTS_STATUS:
1254         case PTRACE_BTS_SIZE:
1255         case PTRACE_BTS_GET:
1256         case PTRACE_BTS_CLEAR:
1257         case PTRACE_BTS_DRAIN:
1258 #endif /* CONFIG_X86_PTRACE_BTS */
1259                 return arch_ptrace(child, request, addr, data);
1260
1261         default:
1262                 return compat_ptrace_request(child, request, addr, data);
1263         }
1264
1265         return ret;
1266 }
1267
1268 #endif  /* CONFIG_IA32_EMULATION */
1269
1270 #ifdef CONFIG_X86_64
1271
1272 static const struct user_regset x86_64_regsets[] = {
1273         [REGSET_GENERAL] = {
1274                 .core_note_type = NT_PRSTATUS,
1275                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1276                 .size = sizeof(long), .align = sizeof(long),
1277                 .get = genregs_get, .set = genregs_set
1278         },
1279         [REGSET_FP] = {
1280                 .core_note_type = NT_PRFPREG,
1281                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1282                 .size = sizeof(long), .align = sizeof(long),
1283                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1284         },
1285         [REGSET_IOPERM64] = {
1286                 .core_note_type = NT_386_IOPERM,
1287                 .n = IO_BITMAP_LONGS,
1288                 .size = sizeof(long), .align = sizeof(long),
1289                 .active = ioperm_active, .get = ioperm_get
1290         },
1291 };
1292
1293 static const struct user_regset_view user_x86_64_view = {
1294         .name = "x86_64", .e_machine = EM_X86_64,
1295         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1296 };
1297
1298 #else  /* CONFIG_X86_32 */
1299
1300 #define user_regs_struct32      user_regs_struct
1301 #define genregs32_get           genregs_get
1302 #define genregs32_set           genregs_set
1303
1304 #define user_i387_ia32_struct   user_i387_struct
1305 #define user32_fxsr_struct      user_fxsr_struct
1306
1307 #endif  /* CONFIG_X86_64 */
1308
1309 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1310 static const struct user_regset x86_32_regsets[] = {
1311         [REGSET_GENERAL] = {
1312                 .core_note_type = NT_PRSTATUS,
1313                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1314                 .size = sizeof(u32), .align = sizeof(u32),
1315                 .get = genregs32_get, .set = genregs32_set
1316         },
1317         [REGSET_FP] = {
1318                 .core_note_type = NT_PRFPREG,
1319                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1320                 .size = sizeof(u32), .align = sizeof(u32),
1321                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1322         },
1323         [REGSET_XFP] = {
1324                 .core_note_type = NT_PRXFPREG,
1325                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1326                 .size = sizeof(u32), .align = sizeof(u32),
1327                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1328         },
1329         [REGSET_TLS] = {
1330                 .core_note_type = NT_386_TLS,
1331                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1332                 .size = sizeof(struct user_desc),
1333                 .align = sizeof(struct user_desc),
1334                 .active = regset_tls_active,
1335                 .get = regset_tls_get, .set = regset_tls_set
1336         },
1337         [REGSET_IOPERM32] = {
1338                 .core_note_type = NT_386_IOPERM,
1339                 .n = IO_BITMAP_BYTES / sizeof(u32),
1340                 .size = sizeof(u32), .align = sizeof(u32),
1341                 .active = ioperm_active, .get = ioperm_get
1342         },
1343 };
1344
1345 static const struct user_regset_view user_x86_32_view = {
1346         .name = "i386", .e_machine = EM_386,
1347         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1348 };
1349 #endif
1350
1351 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1352 {
1353 #ifdef CONFIG_IA32_EMULATION
1354         if (test_tsk_thread_flag(task, TIF_IA32))
1355 #endif
1356 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1357                 return &user_x86_32_view;
1358 #endif
1359 #ifdef CONFIG_X86_64
1360         return &user_x86_64_view;
1361 #endif
1362 }
1363
1364 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1365                                          int error_code, int si_code)
1366 {
1367         struct siginfo info;
1368
1369         tsk->thread.trap_no = 1;
1370         tsk->thread.error_code = error_code;
1371
1372         memset(&info, 0, sizeof(info));
1373         info.si_signo = SIGTRAP;
1374         info.si_code = si_code;
1375
1376         /* User-mode ip? */
1377         info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
1378
1379         /* Send us the fake SIGTRAP */
1380         force_sig_info(SIGTRAP, &info, tsk);
1381 }
1382
1383
1384 #ifdef CONFIG_X86_32
1385 # define IS_IA32        1
1386 #elif defined CONFIG_IA32_EMULATION
1387 # define IS_IA32        is_compat_task()
1388 #else
1389 # define IS_IA32        0
1390 #endif
1391
1392 /*
1393  * We must return the syscall number to actually look up in the table.
1394  * This can be -1L to skip running any syscall at all.
1395  */
1396 asmregparm long syscall_trace_enter(struct pt_regs *regs)
1397 {
1398         long ret = 0;
1399
1400         /*
1401          * If we stepped into a sysenter/syscall insn, it trapped in
1402          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1403          * If user-mode had set TF itself, then it's still clear from
1404          * do_debug() and we need to set it again to restore the user
1405          * state.  If we entered on the slow path, TF was already set.
1406          */
1407         if (test_thread_flag(TIF_SINGLESTEP))
1408                 regs->flags |= X86_EFLAGS_TF;
1409
1410         /* do the secure computing check first */
1411         secure_computing(regs->orig_ax);
1412
1413         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1414                 ret = -1L;
1415
1416         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1417             tracehook_report_syscall_entry(regs))
1418                 ret = -1L;
1419
1420         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
1421                 ftrace_syscall_enter(regs);
1422
1423         if (unlikely(current->audit_context)) {
1424                 if (IS_IA32)
1425                         audit_syscall_entry(AUDIT_ARCH_I386,
1426                                             regs->orig_ax,
1427                                             regs->bx, regs->cx,
1428                                             regs->dx, regs->si);
1429 #ifdef CONFIG_X86_64
1430                 else
1431                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1432                                             regs->orig_ax,
1433                                             regs->di, regs->si,
1434                                             regs->dx, regs->r10);
1435 #endif
1436         }
1437
1438         return ret ?: regs->orig_ax;
1439 }
1440
1441 asmregparm void syscall_trace_leave(struct pt_regs *regs)
1442 {
1443         if (unlikely(current->audit_context))
1444                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1445
1446         if (unlikely(test_thread_flag(TIF_SYSCALL_FTRACE)))
1447                 ftrace_syscall_exit(regs);
1448
1449         if (test_thread_flag(TIF_SYSCALL_TRACE))
1450                 tracehook_report_syscall_exit(regs, 0);
1451
1452         /*
1453          * If TIF_SYSCALL_EMU is set, we only get here because of
1454          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1455          * We already reported this syscall instruction in
1456          * syscall_trace_enter(), so don't do any more now.
1457          */
1458         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1459                 return;
1460
1461         /*
1462          * If we are single-stepping, synthesize a trap to follow the
1463          * system call instruction.
1464          */
1465         if (test_thread_flag(TIF_SINGLESTEP) &&
1466             tracehook_consider_fatal_signal(current, SIGTRAP))
1467                 send_sigtrap(current, regs, 0, TRAP_BRKPT);
1468 }