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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/user.h>
18 #include <linux/elf.h>
19 #include <linux/security.h>
20 #include <linux/audit.h>
21 #include <linux/seccomp.h>
22 #include <linux/signal.h>
23
24 #include <asm/uaccess.h>
25 #include <asm/pgtable.h>
26 #include <asm/system.h>
27 #include <asm/processor.h>
28 #include <asm/i387.h>
29 #include <asm/debugreg.h>
30 #include <asm/ldt.h>
31 #include <asm/desc.h>
32 #include <asm/prctl.h>
33 #include <asm/proto.h>
34 #include <asm/ds.h>
35
36 #include "tls.h"
37
38 enum x86_regset {
39         REGSET_GENERAL,
40         REGSET_FP,
41         REGSET_XFP,
42         REGSET_TLS,
43 };
44
45 /*
46  * does not yet catch signals sent when the child dies.
47  * in exit.c or in signal.c.
48  */
49
50 /*
51  * Determines which flags the user has access to [1 = access, 0 = no access].
52  */
53 #define FLAG_MASK_32            ((unsigned long)                        \
54                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
55                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
56                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
57                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
58                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
59
60 /*
61  * Determines whether a value may be installed in a segment register.
62  */
63 static inline bool invalid_selector(u16 value)
64 {
65         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
66 }
67
68 #ifdef CONFIG_X86_32
69
70 #define FLAG_MASK               FLAG_MASK_32
71
72 static long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
73 {
74         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
75         regno >>= 2;
76         if (regno > FS)
77                 --regno;
78         return &regs->bx + regno;
79 }
80
81 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
82 {
83         /*
84          * Returning the value truncates it to 16 bits.
85          */
86         unsigned int retval;
87         if (offset != offsetof(struct user_regs_struct, gs))
88                 retval = *pt_regs_access(task_pt_regs(task), offset);
89         else {
90                 retval = task->thread.gs;
91                 if (task == current)
92                         savesegment(gs, retval);
93         }
94         return retval;
95 }
96
97 static int set_segment_reg(struct task_struct *task,
98                            unsigned long offset, u16 value)
99 {
100         /*
101          * The value argument was already truncated to 16 bits.
102          */
103         if (invalid_selector(value))
104                 return -EIO;
105
106         if (offset != offsetof(struct user_regs_struct, gs))
107                 *pt_regs_access(task_pt_regs(task), offset) = value;
108         else {
109                 task->thread.gs = value;
110                 if (task == current)
111                         /*
112                          * The user-mode %gs is not affected by
113                          * kernel entry, so we must update the CPU.
114                          */
115                         loadsegment(gs, value);
116         }
117
118         return 0;
119 }
120
121 static unsigned long debugreg_addr_limit(struct task_struct *task)
122 {
123         return TASK_SIZE - 3;
124 }
125
126 #else  /* CONFIG_X86_64 */
127
128 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
129
130 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
131 {
132         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
133         return &regs->r15 + (offset / sizeof(regs->r15));
134 }
135
136 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
137 {
138         /*
139          * Returning the value truncates it to 16 bits.
140          */
141         unsigned int seg;
142
143         switch (offset) {
144         case offsetof(struct user_regs_struct, fs):
145                 if (task == current) {
146                         /* Older gas can't assemble movq %?s,%r?? */
147                         asm("movl %%fs,%0" : "=r" (seg));
148                         return seg;
149                 }
150                 return task->thread.fsindex;
151         case offsetof(struct user_regs_struct, gs):
152                 if (task == current) {
153                         asm("movl %%gs,%0" : "=r" (seg));
154                         return seg;
155                 }
156                 return task->thread.gsindex;
157         case offsetof(struct user_regs_struct, ds):
158                 if (task == current) {
159                         asm("movl %%ds,%0" : "=r" (seg));
160                         return seg;
161                 }
162                 return task->thread.ds;
163         case offsetof(struct user_regs_struct, es):
164                 if (task == current) {
165                         asm("movl %%es,%0" : "=r" (seg));
166                         return seg;
167                 }
168                 return task->thread.es;
169
170         case offsetof(struct user_regs_struct, cs):
171         case offsetof(struct user_regs_struct, ss):
172                 break;
173         }
174         return *pt_regs_access(task_pt_regs(task), offset);
175 }
176
177 static int set_segment_reg(struct task_struct *task,
178                            unsigned long offset, u16 value)
179 {
180         /*
181          * The value argument was already truncated to 16 bits.
182          */
183         if (invalid_selector(value))
184                 return -EIO;
185
186         switch (offset) {
187         case offsetof(struct user_regs_struct,fs):
188                 /*
189                  * If this is setting fs as for normal 64-bit use but
190                  * setting fs_base has implicitly changed it, leave it.
191                  */
192                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
193                      task->thread.fs != 0) ||
194                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
195                      task->thread.fs == 0))
196                         break;
197                 task->thread.fsindex = value;
198                 if (task == current)
199                         loadsegment(fs, task->thread.fsindex);
200                 break;
201         case offsetof(struct user_regs_struct,gs):
202                 /*
203                  * If this is setting gs as for normal 64-bit use but
204                  * setting gs_base has implicitly changed it, leave it.
205                  */
206                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
207                      task->thread.gs != 0) ||
208                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
209                      task->thread.gs == 0))
210                         break;
211                 task->thread.gsindex = value;
212                 if (task == current)
213                         load_gs_index(task->thread.gsindex);
214                 break;
215         case offsetof(struct user_regs_struct,ds):
216                 task->thread.ds = value;
217                 if (task == current)
218                         loadsegment(ds, task->thread.ds);
219                 break;
220         case offsetof(struct user_regs_struct,es):
221                 task->thread.es = value;
222                 if (task == current)
223                         loadsegment(es, task->thread.es);
224                 break;
225
226                 /*
227                  * Can't actually change these in 64-bit mode.
228                  */
229         case offsetof(struct user_regs_struct,cs):
230 #ifdef CONFIG_IA32_EMULATION
231                 if (test_tsk_thread_flag(task, TIF_IA32))
232                         task_pt_regs(task)->cs = value;
233 #endif
234                 break;
235         case offsetof(struct user_regs_struct,ss):
236 #ifdef CONFIG_IA32_EMULATION
237                 if (test_tsk_thread_flag(task, TIF_IA32))
238                         task_pt_regs(task)->ss = value;
239 #endif
240                 break;
241         }
242
243         return 0;
244 }
245
246 static unsigned long debugreg_addr_limit(struct task_struct *task)
247 {
248 #ifdef CONFIG_IA32_EMULATION
249         if (test_tsk_thread_flag(task, TIF_IA32))
250                 return IA32_PAGE_OFFSET - 3;
251 #endif
252         return TASK_SIZE64 - 7;
253 }
254
255 #endif  /* CONFIG_X86_32 */
256
257 static unsigned long get_flags(struct task_struct *task)
258 {
259         unsigned long retval = task_pt_regs(task)->flags;
260
261         /*
262          * If the debugger set TF, hide it from the readout.
263          */
264         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
265                 retval &= ~X86_EFLAGS_TF;
266
267         return retval;
268 }
269
270 static int set_flags(struct task_struct *task, unsigned long value)
271 {
272         struct pt_regs *regs = task_pt_regs(task);
273
274         /*
275          * If the user value contains TF, mark that
276          * it was not "us" (the debugger) that set it.
277          * If not, make sure it stays set if we had.
278          */
279         if (value & X86_EFLAGS_TF)
280                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
281         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
282                 value |= X86_EFLAGS_TF;
283
284         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
285
286         return 0;
287 }
288
289 static int putreg(struct task_struct *child,
290                   unsigned long offset, unsigned long value)
291 {
292         switch (offset) {
293         case offsetof(struct user_regs_struct, cs):
294         case offsetof(struct user_regs_struct, ds):
295         case offsetof(struct user_regs_struct, es):
296         case offsetof(struct user_regs_struct, fs):
297         case offsetof(struct user_regs_struct, gs):
298         case offsetof(struct user_regs_struct, ss):
299                 return set_segment_reg(child, offset, value);
300
301         case offsetof(struct user_regs_struct, flags):
302                 return set_flags(child, value);
303
304 #ifdef CONFIG_X86_64
305         case offsetof(struct user_regs_struct,fs_base):
306                 if (value >= TASK_SIZE_OF(child))
307                         return -EIO;
308                 /*
309                  * When changing the segment base, use do_arch_prctl
310                  * to set either thread.fs or thread.fsindex and the
311                  * corresponding GDT slot.
312                  */
313                 if (child->thread.fs != value)
314                         return do_arch_prctl(child, ARCH_SET_FS, value);
315                 return 0;
316         case offsetof(struct user_regs_struct,gs_base):
317                 /*
318                  * Exactly the same here as the %fs handling above.
319                  */
320                 if (value >= TASK_SIZE_OF(child))
321                         return -EIO;
322                 if (child->thread.gs != value)
323                         return do_arch_prctl(child, ARCH_SET_GS, value);
324                 return 0;
325 #endif
326         }
327
328         *pt_regs_access(task_pt_regs(child), offset) = value;
329         return 0;
330 }
331
332 static unsigned long getreg(struct task_struct *task, unsigned long offset)
333 {
334         switch (offset) {
335         case offsetof(struct user_regs_struct, cs):
336         case offsetof(struct user_regs_struct, ds):
337         case offsetof(struct user_regs_struct, es):
338         case offsetof(struct user_regs_struct, fs):
339         case offsetof(struct user_regs_struct, gs):
340         case offsetof(struct user_regs_struct, ss):
341                 return get_segment_reg(task, offset);
342
343         case offsetof(struct user_regs_struct, flags):
344                 return get_flags(task);
345
346 #ifdef CONFIG_X86_64
347         case offsetof(struct user_regs_struct, fs_base): {
348                 /*
349                  * do_arch_prctl may have used a GDT slot instead of
350                  * the MSR.  To userland, it appears the same either
351                  * way, except the %fs segment selector might not be 0.
352                  */
353                 unsigned int seg = task->thread.fsindex;
354                 if (task->thread.fs != 0)
355                         return task->thread.fs;
356                 if (task == current)
357                         asm("movl %%fs,%0" : "=r" (seg));
358                 if (seg != FS_TLS_SEL)
359                         return 0;
360                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
361         }
362         case offsetof(struct user_regs_struct, gs_base): {
363                 /*
364                  * Exactly the same here as the %fs handling above.
365                  */
366                 unsigned int seg = task->thread.gsindex;
367                 if (task->thread.gs != 0)
368                         return task->thread.gs;
369                 if (task == current)
370                         asm("movl %%gs,%0" : "=r" (seg));
371                 if (seg != GS_TLS_SEL)
372                         return 0;
373                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
374         }
375 #endif
376         }
377
378         return *pt_regs_access(task_pt_regs(task), offset);
379 }
380
381 static int genregs_get(struct task_struct *target,
382                        const struct user_regset *regset,
383                        unsigned int pos, unsigned int count,
384                        void *kbuf, void __user *ubuf)
385 {
386         if (kbuf) {
387                 unsigned long *k = kbuf;
388                 while (count > 0) {
389                         *k++ = getreg(target, pos);
390                         count -= sizeof(*k);
391                         pos += sizeof(*k);
392                 }
393         } else {
394                 unsigned long __user *u = ubuf;
395                 while (count > 0) {
396                         if (__put_user(getreg(target, pos), u++))
397                                 return -EFAULT;
398                         count -= sizeof(*u);
399                         pos += sizeof(*u);
400                 }
401         }
402
403         return 0;
404 }
405
406 static int genregs_set(struct task_struct *target,
407                        const struct user_regset *regset,
408                        unsigned int pos, unsigned int count,
409                        const void *kbuf, const void __user *ubuf)
410 {
411         int ret = 0;
412         if (kbuf) {
413                 const unsigned long *k = kbuf;
414                 while (count > 0 && !ret) {
415                         ret = putreg(target, pos, *k++);
416                         count -= sizeof(*k);
417                         pos += sizeof(*k);
418                 }
419         } else {
420                 const unsigned long  __user *u = ubuf;
421                 while (count > 0 && !ret) {
422                         unsigned long word;
423                         ret = __get_user(word, u++);
424                         if (ret)
425                                 break;
426                         ret = putreg(target, pos, word);
427                         count -= sizeof(*u);
428                         pos += sizeof(*u);
429                 }
430         }
431         return ret;
432 }
433
434 /*
435  * This function is trivial and will be inlined by the compiler.
436  * Having it separates the implementation details of debug
437  * registers from the interface details of ptrace.
438  */
439 static unsigned long ptrace_get_debugreg(struct task_struct *child, int n)
440 {
441         switch (n) {
442         case 0:         return child->thread.debugreg0;
443         case 1:         return child->thread.debugreg1;
444         case 2:         return child->thread.debugreg2;
445         case 3:         return child->thread.debugreg3;
446         case 6:         return child->thread.debugreg6;
447         case 7:         return child->thread.debugreg7;
448         }
449         return 0;
450 }
451
452 static int ptrace_set_debugreg(struct task_struct *child,
453                                int n, unsigned long data)
454 {
455         int i;
456
457         if (unlikely(n == 4 || n == 5))
458                 return -EIO;
459
460         if (n < 4 && unlikely(data >= debugreg_addr_limit(child)))
461                 return -EIO;
462
463         switch (n) {
464         case 0:         child->thread.debugreg0 = data; break;
465         case 1:         child->thread.debugreg1 = data; break;
466         case 2:         child->thread.debugreg2 = data; break;
467         case 3:         child->thread.debugreg3 = data; break;
468
469         case 6:
470                 if ((data & ~0xffffffffUL) != 0)
471                         return -EIO;
472                 child->thread.debugreg6 = data;
473                 break;
474
475         case 7:
476                 /*
477                  * Sanity-check data. Take one half-byte at once with
478                  * check = (val >> (16 + 4*i)) & 0xf. It contains the
479                  * R/Wi and LENi bits; bits 0 and 1 are R/Wi, and bits
480                  * 2 and 3 are LENi. Given a list of invalid values,
481                  * we do mask |= 1 << invalid_value, so that
482                  * (mask >> check) & 1 is a correct test for invalid
483                  * values.
484                  *
485                  * R/Wi contains the type of the breakpoint /
486                  * watchpoint, LENi contains the length of the watched
487                  * data in the watchpoint case.
488                  *
489                  * The invalid values are:
490                  * - LENi == 0x10 (undefined), so mask |= 0x0f00.       [32-bit]
491                  * - R/Wi == 0x10 (break on I/O reads or writes), so
492                  *   mask |= 0x4444.
493                  * - R/Wi == 0x00 && LENi != 0x00, so we have mask |=
494                  *   0x1110.
495                  *
496                  * Finally, mask = 0x0f00 | 0x4444 | 0x1110 == 0x5f54.
497                  *
498                  * See the Intel Manual "System Programming Guide",
499                  * 15.2.4
500                  *
501                  * Note that LENi == 0x10 is defined on x86_64 in long
502                  * mode (i.e. even for 32-bit userspace software, but
503                  * 64-bit kernel), so the x86_64 mask value is 0x5454.
504                  * See the AMD manual no. 24593 (AMD64 System Programming)
505                  */
506 #ifdef CONFIG_X86_32
507 #define DR7_MASK        0x5f54
508 #else
509 #define DR7_MASK        0x5554
510 #endif
511                 data &= ~DR_CONTROL_RESERVED;
512                 for (i = 0; i < 4; i++)
513                         if ((DR7_MASK >> ((data >> (16 + 4*i)) & 0xf)) & 1)
514                                 return -EIO;
515                 child->thread.debugreg7 = data;
516                 if (data)
517                         set_tsk_thread_flag(child, TIF_DEBUG);
518                 else
519                         clear_tsk_thread_flag(child, TIF_DEBUG);
520                 break;
521         }
522
523         return 0;
524 }
525
526 static int ptrace_bts_get_size(struct task_struct *child)
527 {
528         if (!child->thread.ds_area_msr)
529                 return -ENXIO;
530
531         return ds_get_bts_index((void *)child->thread.ds_area_msr);
532 }
533
534 static int ptrace_bts_read_record(struct task_struct *child,
535                                   long index,
536                                   struct bts_struct __user *out)
537 {
538         struct bts_struct ret;
539         int retval;
540         int bts_end;
541         int bts_index;
542
543         if (!child->thread.ds_area_msr)
544                 return -ENXIO;
545
546         if (index < 0)
547                 return -EINVAL;
548
549         bts_end = ds_get_bts_end((void *)child->thread.ds_area_msr);
550         if (bts_end <= index)
551                 return -EINVAL;
552
553         /* translate the ptrace bts index into the ds bts index */
554         bts_index = ds_get_bts_index((void *)child->thread.ds_area_msr);
555         bts_index -= (index + 1);
556         if (bts_index < 0)
557                 bts_index += bts_end;
558
559         retval = ds_read_bts((void *)child->thread.ds_area_msr,
560                              bts_index, &ret);
561         if (retval < 0)
562                 return retval;
563
564         if (copy_to_user(out, &ret, sizeof(ret)))
565                 return -EFAULT;
566
567         return sizeof(ret);
568 }
569
570 static int ptrace_bts_write_record(struct task_struct *child,
571                                    const struct bts_struct *in)
572 {
573         int retval;
574
575         if (!child->thread.ds_area_msr)
576                 return -ENXIO;
577
578         retval = ds_write_bts((void *)child->thread.ds_area_msr, in);
579         if (retval)
580                 return retval;
581
582         return sizeof(*in);
583 }
584
585 static int ptrace_bts_clear(struct task_struct *child)
586 {
587         if (!child->thread.ds_area_msr)
588                 return -ENXIO;
589
590         return ds_clear((void *)child->thread.ds_area_msr);
591 }
592
593 static int ptrace_bts_drain(struct task_struct *child,
594                             long size,
595                             struct bts_struct __user *out)
596 {
597         int end, i;
598         void *ds = (void *)child->thread.ds_area_msr;
599
600         if (!ds)
601                 return -ENXIO;
602
603         end = ds_get_bts_index(ds);
604         if (end <= 0)
605                 return end;
606
607         if (size < (end * sizeof(struct bts_struct)))
608                 return -EIO;
609
610         for (i = 0; i < end; i++, out++) {
611                 struct bts_struct ret;
612                 int retval;
613
614                 retval = ds_read_bts(ds, i, &ret);
615                 if (retval < 0)
616                         return retval;
617
618                 if (copy_to_user(out, &ret, sizeof(ret)))
619                         return -EFAULT;
620         }
621
622         ds_clear(ds);
623
624         return end;
625 }
626
627 static int ptrace_bts_realloc(struct task_struct *child,
628                               int size, int reduce_size)
629 {
630         unsigned long rlim, vm;
631         int ret, old_size;
632
633         if (size < 0)
634                 return -EINVAL;
635
636         old_size = ds_get_bts_size((void *)child->thread.ds_area_msr);
637         if (old_size < 0)
638                 return old_size;
639
640         ret = ds_free((void **)&child->thread.ds_area_msr);
641         if (ret < 0)
642                 goto out;
643
644         size >>= PAGE_SHIFT;
645         old_size >>= PAGE_SHIFT;
646
647         current->mm->total_vm  -= old_size;
648         current->mm->locked_vm -= old_size;
649
650         if (size == 0)
651                 goto out;
652
653         rlim = current->signal->rlim[RLIMIT_AS].rlim_cur >> PAGE_SHIFT;
654         vm = current->mm->total_vm  + size;
655         if (rlim < vm) {
656                 ret = -ENOMEM;
657
658                 if (!reduce_size)
659                         goto out;
660
661                 size = rlim - current->mm->total_vm;
662                 if (size <= 0)
663                         goto out;
664         }
665
666         rlim = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >> PAGE_SHIFT;
667         vm = current->mm->locked_vm  + size;
668         if (rlim < vm) {
669                 ret = -ENOMEM;
670
671                 if (!reduce_size)
672                         goto out;
673
674                 size = rlim - current->mm->locked_vm;
675                 if (size <= 0)
676                         goto out;
677         }
678
679         ret = ds_allocate((void **)&child->thread.ds_area_msr,
680                           size << PAGE_SHIFT);
681         if (ret < 0)
682                 goto out;
683
684         current->mm->total_vm  += size;
685         current->mm->locked_vm += size;
686
687 out:
688         if (child->thread.ds_area_msr)
689                 set_tsk_thread_flag(child, TIF_DS_AREA_MSR);
690         else
691                 clear_tsk_thread_flag(child, TIF_DS_AREA_MSR);
692
693         return ret;
694 }
695
696 static int ptrace_bts_config(struct task_struct *child,
697                              long cfg_size,
698                              const struct ptrace_bts_config __user *ucfg)
699 {
700         struct ptrace_bts_config cfg;
701         int bts_size, ret = 0;
702         void *ds;
703
704         if (cfg_size < sizeof(cfg))
705                 return -EIO;
706
707         if (copy_from_user(&cfg, ucfg, sizeof(cfg)))
708                 return -EFAULT;
709
710         if ((int)cfg.size < 0)
711                 return -EINVAL;
712
713         bts_size = 0;
714         ds = (void *)child->thread.ds_area_msr;
715         if (ds) {
716                 bts_size = ds_get_bts_size(ds);
717                 if (bts_size < 0)
718                         return bts_size;
719         }
720         cfg.size = PAGE_ALIGN(cfg.size);
721
722         if (bts_size != cfg.size) {
723                 ret = ptrace_bts_realloc(child, cfg.size,
724                                          cfg.flags & PTRACE_BTS_O_CUT_SIZE);
725                 if (ret < 0)
726                         goto errout;
727
728                 ds = (void *)child->thread.ds_area_msr;
729         }
730
731         if (cfg.flags & PTRACE_BTS_O_SIGNAL)
732                 ret = ds_set_overflow(ds, DS_O_SIGNAL);
733         else
734                 ret = ds_set_overflow(ds, DS_O_WRAP);
735         if (ret < 0)
736                 goto errout;
737
738         if (cfg.flags & PTRACE_BTS_O_TRACE)
739                 child->thread.debugctlmsr |= ds_debugctl_mask();
740         else
741                 child->thread.debugctlmsr &= ~ds_debugctl_mask();
742
743         if (cfg.flags & PTRACE_BTS_O_SCHED)
744                 set_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
745         else
746                 clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
747
748         ret = sizeof(cfg);
749
750 out:
751         if (child->thread.debugctlmsr)
752                 set_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
753         else
754                 clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
755
756         return ret;
757
758 errout:
759         child->thread.debugctlmsr &= ~ds_debugctl_mask();
760         clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
761         goto out;
762 }
763
764 static int ptrace_bts_status(struct task_struct *child,
765                              long cfg_size,
766                              struct ptrace_bts_config __user *ucfg)
767 {
768         void *ds = (void *)child->thread.ds_area_msr;
769         struct ptrace_bts_config cfg;
770
771         if (cfg_size < sizeof(cfg))
772                 return -EIO;
773
774         memset(&cfg, 0, sizeof(cfg));
775
776         if (ds) {
777                 cfg.size = ds_get_bts_size(ds);
778
779                 if (ds_get_overflow(ds) == DS_O_SIGNAL)
780                         cfg.flags |= PTRACE_BTS_O_SIGNAL;
781
782                 if (test_tsk_thread_flag(child, TIF_DEBUGCTLMSR) &&
783                     child->thread.debugctlmsr & ds_debugctl_mask())
784                         cfg.flags |= PTRACE_BTS_O_TRACE;
785
786                 if (test_tsk_thread_flag(child, TIF_BTS_TRACE_TS))
787                         cfg.flags |= PTRACE_BTS_O_SCHED;
788         }
789
790         cfg.bts_size = sizeof(struct bts_struct);
791
792         if (copy_to_user(ucfg, &cfg, sizeof(cfg)))
793                 return -EFAULT;
794
795         return sizeof(cfg);
796 }
797
798 void ptrace_bts_take_timestamp(struct task_struct *tsk,
799                                enum bts_qualifier qualifier)
800 {
801         struct bts_struct rec = {
802                 .qualifier = qualifier,
803                 .variant.jiffies = jiffies_64
804         };
805
806         ptrace_bts_write_record(tsk, &rec);
807 }
808
809 /*
810  * Called by kernel/ptrace.c when detaching..
811  *
812  * Make sure the single step bit is not set.
813  */
814 void ptrace_disable(struct task_struct *child)
815 {
816         user_disable_single_step(child);
817 #ifdef TIF_SYSCALL_EMU
818         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
819 #endif
820         if (child->thread.ds_area_msr) {
821                 ptrace_bts_realloc(child, 0, 0);
822                 child->thread.debugctlmsr &= ~ds_debugctl_mask();
823                 if (!child->thread.debugctlmsr)
824                         clear_tsk_thread_flag(child, TIF_DEBUGCTLMSR);
825                 clear_tsk_thread_flag(child, TIF_BTS_TRACE_TS);
826         }
827 }
828
829 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
830 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
831 #endif
832
833 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
834 {
835         int ret;
836         unsigned long __user *datap = (unsigned long __user *)data;
837
838         switch (request) {
839         /* read the word at location addr in the USER area. */
840         case PTRACE_PEEKUSR: {
841                 unsigned long tmp;
842
843                 ret = -EIO;
844                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
845                     addr >= sizeof(struct user))
846                         break;
847
848                 tmp = 0;  /* Default return condition */
849                 if (addr < sizeof(struct user_regs_struct))
850                         tmp = getreg(child, addr);
851                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
852                          addr <= offsetof(struct user, u_debugreg[7])) {
853                         addr -= offsetof(struct user, u_debugreg[0]);
854                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
855                 }
856                 ret = put_user(tmp, datap);
857                 break;
858         }
859
860         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
861                 ret = -EIO;
862                 if ((addr & (sizeof(data) - 1)) || addr < 0 ||
863                     addr >= sizeof(struct user))
864                         break;
865
866                 if (addr < sizeof(struct user_regs_struct))
867                         ret = putreg(child, addr, data);
868                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
869                          addr <= offsetof(struct user, u_debugreg[7])) {
870                         addr -= offsetof(struct user, u_debugreg[0]);
871                         ret = ptrace_set_debugreg(child,
872                                                   addr / sizeof(data), data);
873                 }
874                 break;
875
876         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
877                 return copy_regset_to_user(child,
878                                            task_user_regset_view(current),
879                                            REGSET_GENERAL,
880                                            0, sizeof(struct user_regs_struct),
881                                            datap);
882
883         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
884                 return copy_regset_from_user(child,
885                                              task_user_regset_view(current),
886                                              REGSET_GENERAL,
887                                              0, sizeof(struct user_regs_struct),
888                                              datap);
889
890         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
891                 return copy_regset_to_user(child,
892                                            task_user_regset_view(current),
893                                            REGSET_FP,
894                                            0, sizeof(struct user_i387_struct),
895                                            datap);
896
897         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
898                 return copy_regset_from_user(child,
899                                              task_user_regset_view(current),
900                                              REGSET_FP,
901                                              0, sizeof(struct user_i387_struct),
902                                              datap);
903
904 #ifdef CONFIG_X86_32
905         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
906                 return copy_regset_to_user(child, &user_x86_32_view,
907                                            REGSET_XFP,
908                                            0, sizeof(struct user_fxsr_struct),
909                                            datap);
910
911         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
912                 return copy_regset_from_user(child, &user_x86_32_view,
913                                              REGSET_XFP,
914                                              0, sizeof(struct user_fxsr_struct),
915                                              datap);
916 #endif
917
918 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
919         case PTRACE_GET_THREAD_AREA:
920                 if (addr < 0)
921                         return -EIO;
922                 ret = do_get_thread_area(child, addr,
923                                          (struct user_desc __user *) data);
924                 break;
925
926         case PTRACE_SET_THREAD_AREA:
927                 if (addr < 0)
928                         return -EIO;
929                 ret = do_set_thread_area(child, addr,
930                                          (struct user_desc __user *) data, 0);
931                 break;
932 #endif
933
934 #ifdef CONFIG_X86_64
935                 /* normal 64bit interface to access TLS data.
936                    Works just like arch_prctl, except that the arguments
937                    are reversed. */
938         case PTRACE_ARCH_PRCTL:
939                 ret = do_arch_prctl(child, data, addr);
940                 break;
941 #endif
942
943         case PTRACE_BTS_CONFIG:
944                 ret = ptrace_bts_config
945                         (child, data, (struct ptrace_bts_config __user *)addr);
946                 break;
947
948         case PTRACE_BTS_STATUS:
949                 ret = ptrace_bts_status
950                         (child, data, (struct ptrace_bts_config __user *)addr);
951                 break;
952
953         case PTRACE_BTS_SIZE:
954                 ret = ptrace_bts_get_size(child);
955                 break;
956
957         case PTRACE_BTS_GET:
958                 ret = ptrace_bts_read_record
959                         (child, data, (struct bts_struct __user *) addr);
960                 break;
961
962         case PTRACE_BTS_CLEAR:
963                 ret = ptrace_bts_clear(child);
964                 break;
965
966         case PTRACE_BTS_DRAIN:
967                 ret = ptrace_bts_drain
968                         (child, data, (struct bts_struct __user *) addr);
969                 break;
970
971         default:
972                 ret = ptrace_request(child, request, addr, data);
973                 break;
974         }
975
976         return ret;
977 }
978
979 #ifdef CONFIG_IA32_EMULATION
980
981 #include <linux/compat.h>
982 #include <linux/syscalls.h>
983 #include <asm/ia32.h>
984 #include <asm/user32.h>
985
986 #define R32(l,q)                                                        \
987         case offsetof(struct user32, regs.l):                           \
988                 regs->q = value; break
989
990 #define SEG32(rs)                                                       \
991         case offsetof(struct user32, regs.rs):                          \
992                 return set_segment_reg(child,                           \
993                                        offsetof(struct user_regs_struct, rs), \
994                                        value);                          \
995                 break
996
997 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
998 {
999         struct pt_regs *regs = task_pt_regs(child);
1000
1001         switch (regno) {
1002
1003         SEG32(cs);
1004         SEG32(ds);
1005         SEG32(es);
1006         SEG32(fs);
1007         SEG32(gs);
1008         SEG32(ss);
1009
1010         R32(ebx, bx);
1011         R32(ecx, cx);
1012         R32(edx, dx);
1013         R32(edi, di);
1014         R32(esi, si);
1015         R32(ebp, bp);
1016         R32(eax, ax);
1017         R32(orig_eax, orig_ax);
1018         R32(eip, ip);
1019         R32(esp, sp);
1020
1021         case offsetof(struct user32, regs.eflags):
1022                 return set_flags(child, value);
1023
1024         case offsetof(struct user32, u_debugreg[0]) ...
1025                 offsetof(struct user32, u_debugreg[7]):
1026                 regno -= offsetof(struct user32, u_debugreg[0]);
1027                 return ptrace_set_debugreg(child, regno / 4, value);
1028
1029         default:
1030                 if (regno > sizeof(struct user32) || (regno & 3))
1031                         return -EIO;
1032
1033                 /*
1034                  * Other dummy fields in the virtual user structure
1035                  * are ignored
1036                  */
1037                 break;
1038         }
1039         return 0;
1040 }
1041
1042 #undef R32
1043 #undef SEG32
1044
1045 #define R32(l,q)                                                        \
1046         case offsetof(struct user32, regs.l):                           \
1047                 *val = regs->q; break
1048
1049 #define SEG32(rs)                                                       \
1050         case offsetof(struct user32, regs.rs):                          \
1051                 *val = get_segment_reg(child,                           \
1052                                        offsetof(struct user_regs_struct, rs)); \
1053                 break
1054
1055 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1056 {
1057         struct pt_regs *regs = task_pt_regs(child);
1058
1059         switch (regno) {
1060
1061         SEG32(ds);
1062         SEG32(es);
1063         SEG32(fs);
1064         SEG32(gs);
1065
1066         R32(cs, cs);
1067         R32(ss, ss);
1068         R32(ebx, bx);
1069         R32(ecx, cx);
1070         R32(edx, dx);
1071         R32(edi, di);
1072         R32(esi, si);
1073         R32(ebp, bp);
1074         R32(eax, ax);
1075         R32(orig_eax, orig_ax);
1076         R32(eip, ip);
1077         R32(esp, sp);
1078
1079         case offsetof(struct user32, regs.eflags):
1080                 *val = get_flags(child);
1081                 break;
1082
1083         case offsetof(struct user32, u_debugreg[0]) ...
1084                 offsetof(struct user32, u_debugreg[7]):
1085                 regno -= offsetof(struct user32, u_debugreg[0]);
1086                 *val = ptrace_get_debugreg(child, regno / 4);
1087                 break;
1088
1089         default:
1090                 if (regno > sizeof(struct user32) || (regno & 3))
1091                         return -EIO;
1092
1093                 /*
1094                  * Other dummy fields in the virtual user structure
1095                  * are ignored
1096                  */
1097                 *val = 0;
1098                 break;
1099         }
1100         return 0;
1101 }
1102
1103 #undef R32
1104 #undef SEG32
1105
1106 static int genregs32_get(struct task_struct *target,
1107                          const struct user_regset *regset,
1108                          unsigned int pos, unsigned int count,
1109                          void *kbuf, void __user *ubuf)
1110 {
1111         if (kbuf) {
1112                 compat_ulong_t *k = kbuf;
1113                 while (count > 0) {
1114                         getreg32(target, pos, k++);
1115                         count -= sizeof(*k);
1116                         pos += sizeof(*k);
1117                 }
1118         } else {
1119                 compat_ulong_t __user *u = ubuf;
1120                 while (count > 0) {
1121                         compat_ulong_t word;
1122                         getreg32(target, pos, &word);
1123                         if (__put_user(word, u++))
1124                                 return -EFAULT;
1125                         count -= sizeof(*u);
1126                         pos += sizeof(*u);
1127                 }
1128         }
1129
1130         return 0;
1131 }
1132
1133 static int genregs32_set(struct task_struct *target,
1134                          const struct user_regset *regset,
1135                          unsigned int pos, unsigned int count,
1136                          const void *kbuf, const void __user *ubuf)
1137 {
1138         int ret = 0;
1139         if (kbuf) {
1140                 const compat_ulong_t *k = kbuf;
1141                 while (count > 0 && !ret) {
1142                         ret = putreg(target, pos, *k++);
1143                         count -= sizeof(*k);
1144                         pos += sizeof(*k);
1145                 }
1146         } else {
1147                 const compat_ulong_t __user *u = ubuf;
1148                 while (count > 0 && !ret) {
1149                         compat_ulong_t word;
1150                         ret = __get_user(word, u++);
1151                         if (ret)
1152                                 break;
1153                         ret = putreg(target, pos, word);
1154                         count -= sizeof(*u);
1155                         pos += sizeof(*u);
1156                 }
1157         }
1158         return ret;
1159 }
1160
1161 static long ptrace32_siginfo(unsigned request, u32 pid, u32 addr, u32 data)
1162 {
1163         siginfo_t __user *si = compat_alloc_user_space(sizeof(siginfo_t));
1164         compat_siginfo_t __user *si32 = compat_ptr(data);
1165         siginfo_t ssi;
1166         int ret;
1167
1168         if (request == PTRACE_SETSIGINFO) {
1169                 memset(&ssi, 0, sizeof(siginfo_t));
1170                 ret = copy_siginfo_from_user32(&ssi, si32);
1171                 if (ret)
1172                         return ret;
1173                 if (copy_to_user(si, &ssi, sizeof(siginfo_t)))
1174                         return -EFAULT;
1175         }
1176         ret = sys_ptrace(request, pid, addr, (unsigned long)si);
1177         if (ret)
1178                 return ret;
1179         if (request == PTRACE_GETSIGINFO) {
1180                 if (copy_from_user(&ssi, si, sizeof(siginfo_t)))
1181                         return -EFAULT;
1182                 ret = copy_siginfo_to_user32(si32, &ssi);
1183         }
1184         return ret;
1185 }
1186
1187 asmlinkage long sys32_ptrace(long request, u32 pid, u32 addr, u32 data)
1188 {
1189         struct task_struct *child;
1190         struct pt_regs *childregs;
1191         void __user *datap = compat_ptr(data);
1192         int ret;
1193         __u32 val;
1194
1195         switch (request) {
1196         case PTRACE_TRACEME:
1197         case PTRACE_ATTACH:
1198         case PTRACE_KILL:
1199         case PTRACE_CONT:
1200         case PTRACE_SINGLESTEP:
1201         case PTRACE_SINGLEBLOCK:
1202         case PTRACE_DETACH:
1203         case PTRACE_SYSCALL:
1204         case PTRACE_OLDSETOPTIONS:
1205         case PTRACE_SETOPTIONS:
1206         case PTRACE_SET_THREAD_AREA:
1207         case PTRACE_GET_THREAD_AREA:
1208         case PTRACE_BTS_CONFIG:
1209         case PTRACE_BTS_STATUS:
1210         case PTRACE_BTS_SIZE:
1211         case PTRACE_BTS_GET:
1212         case PTRACE_BTS_CLEAR:
1213         case PTRACE_BTS_DRAIN:
1214                 return sys_ptrace(request, pid, addr, data);
1215
1216         default:
1217                 return -EINVAL;
1218
1219         case PTRACE_PEEKTEXT:
1220         case PTRACE_PEEKDATA:
1221         case PTRACE_POKEDATA:
1222         case PTRACE_POKETEXT:
1223         case PTRACE_POKEUSR:
1224         case PTRACE_PEEKUSR:
1225         case PTRACE_GETREGS:
1226         case PTRACE_SETREGS:
1227         case PTRACE_SETFPREGS:
1228         case PTRACE_GETFPREGS:
1229         case PTRACE_SETFPXREGS:
1230         case PTRACE_GETFPXREGS:
1231         case PTRACE_GETEVENTMSG:
1232                 break;
1233
1234         case PTRACE_SETSIGINFO:
1235         case PTRACE_GETSIGINFO:
1236                 return ptrace32_siginfo(request, pid, addr, data);
1237         }
1238
1239         child = ptrace_get_task_struct(pid);
1240         if (IS_ERR(child))
1241                 return PTR_ERR(child);
1242
1243         ret = ptrace_check_attach(child, request == PTRACE_KILL);
1244         if (ret < 0)
1245                 goto out;
1246
1247         childregs = task_pt_regs(child);
1248
1249         switch (request) {
1250         case PTRACE_PEEKUSR:
1251                 ret = getreg32(child, addr, &val);
1252                 if (ret == 0)
1253                         ret = put_user(val, (__u32 __user *)datap);
1254                 break;
1255
1256         case PTRACE_POKEUSR:
1257                 ret = putreg32(child, addr, data);
1258                 break;
1259
1260         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1261                 return copy_regset_to_user(child, &user_x86_32_view,
1262                                            REGSET_GENERAL,
1263                                            0, sizeof(struct user_regs_struct32),
1264                                            datap);
1265
1266         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1267                 return copy_regset_from_user(child, &user_x86_32_view,
1268                                              REGSET_GENERAL, 0,
1269                                              sizeof(struct user_regs_struct32),
1270                                              datap);
1271
1272         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1273                 return copy_regset_to_user(child, &user_x86_32_view,
1274                                            REGSET_FP, 0,
1275                                            sizeof(struct user_i387_ia32_struct),
1276                                            datap);
1277
1278         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1279                 return copy_regset_from_user(
1280                         child, &user_x86_32_view, REGSET_FP,
1281                         0, sizeof(struct user_i387_ia32_struct), datap);
1282
1283         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1284                 return copy_regset_to_user(child, &user_x86_32_view,
1285                                            REGSET_XFP, 0,
1286                                            sizeof(struct user32_fxsr_struct),
1287                                            datap);
1288
1289         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1290                 return copy_regset_from_user(child, &user_x86_32_view,
1291                                              REGSET_XFP, 0,
1292                                              sizeof(struct user32_fxsr_struct),
1293                                              datap);
1294
1295         default:
1296                 return compat_ptrace_request(child, request, addr, data);
1297         }
1298
1299  out:
1300         put_task_struct(child);
1301         return ret;
1302 }
1303
1304 #endif  /* CONFIG_IA32_EMULATION */
1305
1306 #ifdef CONFIG_X86_64
1307
1308 static const struct user_regset x86_64_regsets[] = {
1309         [REGSET_GENERAL] = {
1310                 .core_note_type = NT_PRSTATUS,
1311                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1312                 .size = sizeof(long), .align = sizeof(long),
1313                 .get = genregs_get, .set = genregs_set
1314         },
1315         [REGSET_FP] = {
1316                 .core_note_type = NT_PRFPREG,
1317                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1318                 .size = sizeof(long), .align = sizeof(long),
1319                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1320         },
1321 };
1322
1323 static const struct user_regset_view user_x86_64_view = {
1324         .name = "x86_64", .e_machine = EM_X86_64,
1325         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1326 };
1327
1328 #else  /* CONFIG_X86_32 */
1329
1330 #define user_regs_struct32      user_regs_struct
1331 #define genregs32_get           genregs_get
1332 #define genregs32_set           genregs_set
1333
1334 #endif  /* CONFIG_X86_64 */
1335
1336 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1337 static const struct user_regset x86_32_regsets[] = {
1338         [REGSET_GENERAL] = {
1339                 .core_note_type = NT_PRSTATUS,
1340                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1341                 .size = sizeof(u32), .align = sizeof(u32),
1342                 .get = genregs32_get, .set = genregs32_set
1343         },
1344         [REGSET_FP] = {
1345                 .core_note_type = NT_PRFPREG,
1346                 .n = sizeof(struct user_i387_struct) / sizeof(u32),
1347                 .size = sizeof(u32), .align = sizeof(u32),
1348                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1349         },
1350         [REGSET_XFP] = {
1351                 .core_note_type = NT_PRXFPREG,
1352                 .n = sizeof(struct user_i387_struct) / sizeof(u32),
1353                 .size = sizeof(u32), .align = sizeof(u32),
1354                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1355         },
1356         [REGSET_TLS] = {
1357                 .core_note_type = NT_386_TLS,
1358                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1359                 .size = sizeof(struct user_desc),
1360                 .align = sizeof(struct user_desc),
1361                 .active = regset_tls_active,
1362                 .get = regset_tls_get, .set = regset_tls_set
1363         },
1364 };
1365
1366 static const struct user_regset_view user_x86_32_view = {
1367         .name = "i386", .e_machine = EM_386,
1368         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1369 };
1370 #endif
1371
1372 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1373 {
1374 #ifdef CONFIG_IA32_EMULATION
1375         if (test_tsk_thread_flag(task, TIF_IA32))
1376 #endif
1377 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1378                 return &user_x86_32_view;
1379 #endif
1380 #ifdef CONFIG_X86_64
1381         return &user_x86_64_view;
1382 #endif
1383 }
1384
1385 #ifdef CONFIG_X86_32
1386
1387 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
1388 {
1389         struct siginfo info;
1390
1391         tsk->thread.trap_no = 1;
1392         tsk->thread.error_code = error_code;
1393
1394         memset(&info, 0, sizeof(info));
1395         info.si_signo = SIGTRAP;
1396         info.si_code = TRAP_BRKPT;
1397
1398         /* User-mode ip? */
1399         info.si_addr = user_mode_vm(regs) ? (void __user *) regs->ip : NULL;
1400
1401         /* Send us the fake SIGTRAP */
1402         force_sig_info(SIGTRAP, &info, tsk);
1403 }
1404
1405 /* notification of system call entry/exit
1406  * - triggered by current->work.syscall_trace
1407  */
1408 __attribute__((regparm(3)))
1409 int do_syscall_trace(struct pt_regs *regs, int entryexit)
1410 {
1411         int is_sysemu = test_thread_flag(TIF_SYSCALL_EMU);
1412         /*
1413          * With TIF_SYSCALL_EMU set we want to ignore TIF_SINGLESTEP for syscall
1414          * interception
1415          */
1416         int is_singlestep = !is_sysemu && test_thread_flag(TIF_SINGLESTEP);
1417         int ret = 0;
1418
1419         /* do the secure computing check first */
1420         if (!entryexit)
1421                 secure_computing(regs->orig_ax);
1422
1423         if (unlikely(current->audit_context)) {
1424                 if (entryexit)
1425                         audit_syscall_exit(AUDITSC_RESULT(regs->ax),
1426                                                 regs->ax);
1427                 /* Debug traps, when using PTRACE_SINGLESTEP, must be sent only
1428                  * on the syscall exit path. Normally, when TIF_SYSCALL_AUDIT is
1429                  * not used, entry.S will call us only on syscall exit, not
1430                  * entry; so when TIF_SYSCALL_AUDIT is used we must avoid
1431                  * calling send_sigtrap() on syscall entry.
1432                  *
1433                  * Note that when PTRACE_SYSEMU_SINGLESTEP is used,
1434                  * is_singlestep is false, despite his name, so we will still do
1435                  * the correct thing.
1436                  */
1437                 else if (is_singlestep)
1438                         goto out;
1439         }
1440
1441         if (!(current->ptrace & PT_PTRACED))
1442                 goto out;
1443
1444         /* If a process stops on the 1st tracepoint with SYSCALL_TRACE
1445          * and then is resumed with SYSEMU_SINGLESTEP, it will come in
1446          * here. We have to check this and return */
1447         if (is_sysemu && entryexit)
1448                 return 0;
1449
1450         /* Fake a debug trap */
1451         if (is_singlestep)
1452                 send_sigtrap(current, regs, 0);
1453
1454         if (!test_thread_flag(TIF_SYSCALL_TRACE) && !is_sysemu)
1455                 goto out;
1456
1457         /* the 0x80 provides a way for the tracing parent to distinguish
1458            between a syscall stop and SIGTRAP delivery */
1459         /* Note that the debugger could change the result of test_thread_flag!*/
1460         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ? 0x80:0));
1461
1462         /*
1463          * this isn't the same as continuing with a signal, but it will do
1464          * for normal use.  strace only continues with a signal if the
1465          * stopping signal is not SIGTRAP.  -brl
1466          */
1467         if (current->exit_code) {
1468                 send_sig(current->exit_code, current, 1);
1469                 current->exit_code = 0;
1470         }
1471         ret = is_sysemu;
1472 out:
1473         if (unlikely(current->audit_context) && !entryexit)
1474                 audit_syscall_entry(AUDIT_ARCH_I386, regs->orig_ax,
1475                                     regs->bx, regs->cx, regs->dx, regs->si);
1476         if (ret == 0)
1477                 return 0;
1478
1479         regs->orig_ax = -1; /* force skip of syscall restarting */
1480         if (unlikely(current->audit_context))
1481                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1482         return 1;
1483 }
1484
1485 #else  /* CONFIG_X86_64 */
1486
1487 static void syscall_trace(struct pt_regs *regs)
1488 {
1489
1490 #if 0
1491         printk("trace %s ip %lx sp %lx ax %d origrax %d caller %lx tiflags %x ptrace %x\n",
1492                current->comm,
1493                regs->ip, regs->sp, regs->ax, regs->orig_ax, __builtin_return_address(0),
1494                current_thread_info()->flags, current->ptrace);
1495 #endif
1496
1497         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
1498                                 ? 0x80 : 0));
1499         /*
1500          * this isn't the same as continuing with a signal, but it will do
1501          * for normal use.  strace only continues with a signal if the
1502          * stopping signal is not SIGTRAP.  -brl
1503          */
1504         if (current->exit_code) {
1505                 send_sig(current->exit_code, current, 1);
1506                 current->exit_code = 0;
1507         }
1508 }
1509
1510 asmlinkage void syscall_trace_enter(struct pt_regs *regs)
1511 {
1512         /* do the secure computing check first */
1513         secure_computing(regs->orig_ax);
1514
1515         if (test_thread_flag(TIF_SYSCALL_TRACE)
1516             && (current->ptrace & PT_PTRACED))
1517                 syscall_trace(regs);
1518
1519         if (unlikely(current->audit_context)) {
1520                 if (test_thread_flag(TIF_IA32)) {
1521                         audit_syscall_entry(AUDIT_ARCH_I386,
1522                                             regs->orig_ax,
1523                                             regs->bx, regs->cx,
1524                                             regs->dx, regs->si);
1525                 } else {
1526                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1527                                             regs->orig_ax,
1528                                             regs->di, regs->si,
1529                                             regs->dx, regs->r10);
1530                 }
1531         }
1532 }
1533
1534 asmlinkage void syscall_trace_leave(struct pt_regs *regs)
1535 {
1536         if (unlikely(current->audit_context))
1537                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1538
1539         if ((test_thread_flag(TIF_SYSCALL_TRACE)
1540              || test_thread_flag(TIF_SINGLESTEP))
1541             && (current->ptrace & PT_PTRACED))
1542                 syscall_trace(regs);
1543 }
1544
1545 #endif  /* CONFIG_X86_32 */