perf: Remove the nmi parameter from the swevent and overflow interface
[linux-2.6.git] / arch / x86 / kernel / ptrace.c
1 /* By Ross Biro 1/23/92 */
2 /*
3  * Pentium III FXSR, SSE support
4  *      Gareth Hughes <gareth@valinux.com>, May 2000
5  */
6
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/mm.h>
10 #include <linux/smp.h>
11 #include <linux/errno.h>
12 #include <linux/slab.h>
13 #include <linux/ptrace.h>
14 #include <linux/regset.h>
15 #include <linux/tracehook.h>
16 #include <linux/user.h>
17 #include <linux/elf.h>
18 #include <linux/security.h>
19 #include <linux/audit.h>
20 #include <linux/seccomp.h>
21 #include <linux/signal.h>
22 #include <linux/perf_event.h>
23 #include <linux/hw_breakpoint.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/hw_breakpoint.h>
36
37 #include "tls.h"
38
39 #define CREATE_TRACE_POINTS
40 #include <trace/events/syscalls.h>
41
42 enum x86_regset {
43         REGSET_GENERAL,
44         REGSET_FP,
45         REGSET_XFP,
46         REGSET_IOPERM64 = REGSET_XFP,
47         REGSET_XSTATE,
48         REGSET_TLS,
49         REGSET_IOPERM32,
50 };
51
52 struct pt_regs_offset {
53         const char *name;
54         int offset;
55 };
56
57 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
58 #define REG_OFFSET_END {.name = NULL, .offset = 0}
59
60 static const struct pt_regs_offset regoffset_table[] = {
61 #ifdef CONFIG_X86_64
62         REG_OFFSET_NAME(r15),
63         REG_OFFSET_NAME(r14),
64         REG_OFFSET_NAME(r13),
65         REG_OFFSET_NAME(r12),
66         REG_OFFSET_NAME(r11),
67         REG_OFFSET_NAME(r10),
68         REG_OFFSET_NAME(r9),
69         REG_OFFSET_NAME(r8),
70 #endif
71         REG_OFFSET_NAME(bx),
72         REG_OFFSET_NAME(cx),
73         REG_OFFSET_NAME(dx),
74         REG_OFFSET_NAME(si),
75         REG_OFFSET_NAME(di),
76         REG_OFFSET_NAME(bp),
77         REG_OFFSET_NAME(ax),
78 #ifdef CONFIG_X86_32
79         REG_OFFSET_NAME(ds),
80         REG_OFFSET_NAME(es),
81         REG_OFFSET_NAME(fs),
82         REG_OFFSET_NAME(gs),
83 #endif
84         REG_OFFSET_NAME(orig_ax),
85         REG_OFFSET_NAME(ip),
86         REG_OFFSET_NAME(cs),
87         REG_OFFSET_NAME(flags),
88         REG_OFFSET_NAME(sp),
89         REG_OFFSET_NAME(ss),
90         REG_OFFSET_END,
91 };
92
93 /**
94  * regs_query_register_offset() - query register offset from its name
95  * @name:       the name of a register
96  *
97  * regs_query_register_offset() returns the offset of a register in struct
98  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
99  */
100 int regs_query_register_offset(const char *name)
101 {
102         const struct pt_regs_offset *roff;
103         for (roff = regoffset_table; roff->name != NULL; roff++)
104                 if (!strcmp(roff->name, name))
105                         return roff->offset;
106         return -EINVAL;
107 }
108
109 /**
110  * regs_query_register_name() - query register name from its offset
111  * @offset:     the offset of a register in struct pt_regs.
112  *
113  * regs_query_register_name() returns the name of a register from its
114  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
115  */
116 const char *regs_query_register_name(unsigned int offset)
117 {
118         const struct pt_regs_offset *roff;
119         for (roff = regoffset_table; roff->name != NULL; roff++)
120                 if (roff->offset == offset)
121                         return roff->name;
122         return NULL;
123 }
124
125 static const int arg_offs_table[] = {
126 #ifdef CONFIG_X86_32
127         [0] = offsetof(struct pt_regs, ax),
128         [1] = offsetof(struct pt_regs, dx),
129         [2] = offsetof(struct pt_regs, cx)
130 #else /* CONFIG_X86_64 */
131         [0] = offsetof(struct pt_regs, di),
132         [1] = offsetof(struct pt_regs, si),
133         [2] = offsetof(struct pt_regs, dx),
134         [3] = offsetof(struct pt_regs, cx),
135         [4] = offsetof(struct pt_regs, r8),
136         [5] = offsetof(struct pt_regs, r9)
137 #endif
138 };
139
140 /*
141  * does not yet catch signals sent when the child dies.
142  * in exit.c or in signal.c.
143  */
144
145 /*
146  * Determines which flags the user has access to [1 = access, 0 = no access].
147  */
148 #define FLAG_MASK_32            ((unsigned long)                        \
149                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
150                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
151                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
152                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
153                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
154
155 /*
156  * Determines whether a value may be installed in a segment register.
157  */
158 static inline bool invalid_selector(u16 value)
159 {
160         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
161 }
162
163 #ifdef CONFIG_X86_32
164
165 #define FLAG_MASK               FLAG_MASK_32
166
167 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
168 {
169         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
170         return &regs->bx + (regno >> 2);
171 }
172
173 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
174 {
175         /*
176          * Returning the value truncates it to 16 bits.
177          */
178         unsigned int retval;
179         if (offset != offsetof(struct user_regs_struct, gs))
180                 retval = *pt_regs_access(task_pt_regs(task), offset);
181         else {
182                 if (task == current)
183                         retval = get_user_gs(task_pt_regs(task));
184                 else
185                         retval = task_user_gs(task);
186         }
187         return retval;
188 }
189
190 static int set_segment_reg(struct task_struct *task,
191                            unsigned long offset, u16 value)
192 {
193         /*
194          * The value argument was already truncated to 16 bits.
195          */
196         if (invalid_selector(value))
197                 return -EIO;
198
199         /*
200          * For %cs and %ss we cannot permit a null selector.
201          * We can permit a bogus selector as long as it has USER_RPL.
202          * Null selectors are fine for other segment registers, but
203          * we will never get back to user mode with invalid %cs or %ss
204          * and will take the trap in iret instead.  Much code relies
205          * on user_mode() to distinguish a user trap frame (which can
206          * safely use invalid selectors) from a kernel trap frame.
207          */
208         switch (offset) {
209         case offsetof(struct user_regs_struct, cs):
210         case offsetof(struct user_regs_struct, ss):
211                 if (unlikely(value == 0))
212                         return -EIO;
213
214         default:
215                 *pt_regs_access(task_pt_regs(task), offset) = value;
216                 break;
217
218         case offsetof(struct user_regs_struct, gs):
219                 if (task == current)
220                         set_user_gs(task_pt_regs(task), value);
221                 else
222                         task_user_gs(task) = value;
223         }
224
225         return 0;
226 }
227
228 #else  /* CONFIG_X86_64 */
229
230 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
231
232 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
233 {
234         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
235         return &regs->r15 + (offset / sizeof(regs->r15));
236 }
237
238 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
239 {
240         /*
241          * Returning the value truncates it to 16 bits.
242          */
243         unsigned int seg;
244
245         switch (offset) {
246         case offsetof(struct user_regs_struct, fs):
247                 if (task == current) {
248                         /* Older gas can't assemble movq %?s,%r?? */
249                         asm("movl %%fs,%0" : "=r" (seg));
250                         return seg;
251                 }
252                 return task->thread.fsindex;
253         case offsetof(struct user_regs_struct, gs):
254                 if (task == current) {
255                         asm("movl %%gs,%0" : "=r" (seg));
256                         return seg;
257                 }
258                 return task->thread.gsindex;
259         case offsetof(struct user_regs_struct, ds):
260                 if (task == current) {
261                         asm("movl %%ds,%0" : "=r" (seg));
262                         return seg;
263                 }
264                 return task->thread.ds;
265         case offsetof(struct user_regs_struct, es):
266                 if (task == current) {
267                         asm("movl %%es,%0" : "=r" (seg));
268                         return seg;
269                 }
270                 return task->thread.es;
271
272         case offsetof(struct user_regs_struct, cs):
273         case offsetof(struct user_regs_struct, ss):
274                 break;
275         }
276         return *pt_regs_access(task_pt_regs(task), offset);
277 }
278
279 static int set_segment_reg(struct task_struct *task,
280                            unsigned long offset, u16 value)
281 {
282         /*
283          * The value argument was already truncated to 16 bits.
284          */
285         if (invalid_selector(value))
286                 return -EIO;
287
288         switch (offset) {
289         case offsetof(struct user_regs_struct,fs):
290                 /*
291                  * If this is setting fs as for normal 64-bit use but
292                  * setting fs_base has implicitly changed it, leave it.
293                  */
294                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
295                      task->thread.fs != 0) ||
296                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
297                      task->thread.fs == 0))
298                         break;
299                 task->thread.fsindex = value;
300                 if (task == current)
301                         loadsegment(fs, task->thread.fsindex);
302                 break;
303         case offsetof(struct user_regs_struct,gs):
304                 /*
305                  * If this is setting gs as for normal 64-bit use but
306                  * setting gs_base has implicitly changed it, leave it.
307                  */
308                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
309                      task->thread.gs != 0) ||
310                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
311                      task->thread.gs == 0))
312                         break;
313                 task->thread.gsindex = value;
314                 if (task == current)
315                         load_gs_index(task->thread.gsindex);
316                 break;
317         case offsetof(struct user_regs_struct,ds):
318                 task->thread.ds = value;
319                 if (task == current)
320                         loadsegment(ds, task->thread.ds);
321                 break;
322         case offsetof(struct user_regs_struct,es):
323                 task->thread.es = value;
324                 if (task == current)
325                         loadsegment(es, task->thread.es);
326                 break;
327
328                 /*
329                  * Can't actually change these in 64-bit mode.
330                  */
331         case offsetof(struct user_regs_struct,cs):
332                 if (unlikely(value == 0))
333                         return -EIO;
334 #ifdef CONFIG_IA32_EMULATION
335                 if (test_tsk_thread_flag(task, TIF_IA32))
336                         task_pt_regs(task)->cs = value;
337 #endif
338                 break;
339         case offsetof(struct user_regs_struct,ss):
340                 if (unlikely(value == 0))
341                         return -EIO;
342 #ifdef CONFIG_IA32_EMULATION
343                 if (test_tsk_thread_flag(task, TIF_IA32))
344                         task_pt_regs(task)->ss = value;
345 #endif
346                 break;
347         }
348
349         return 0;
350 }
351
352 #endif  /* CONFIG_X86_32 */
353
354 static unsigned long get_flags(struct task_struct *task)
355 {
356         unsigned long retval = task_pt_regs(task)->flags;
357
358         /*
359          * If the debugger set TF, hide it from the readout.
360          */
361         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
362                 retval &= ~X86_EFLAGS_TF;
363
364         return retval;
365 }
366
367 static int set_flags(struct task_struct *task, unsigned long value)
368 {
369         struct pt_regs *regs = task_pt_regs(task);
370
371         /*
372          * If the user value contains TF, mark that
373          * it was not "us" (the debugger) that set it.
374          * If not, make sure it stays set if we had.
375          */
376         if (value & X86_EFLAGS_TF)
377                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
378         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
379                 value |= X86_EFLAGS_TF;
380
381         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
382
383         return 0;
384 }
385
386 static int putreg(struct task_struct *child,
387                   unsigned long offset, unsigned long value)
388 {
389         switch (offset) {
390         case offsetof(struct user_regs_struct, cs):
391         case offsetof(struct user_regs_struct, ds):
392         case offsetof(struct user_regs_struct, es):
393         case offsetof(struct user_regs_struct, fs):
394         case offsetof(struct user_regs_struct, gs):
395         case offsetof(struct user_regs_struct, ss):
396                 return set_segment_reg(child, offset, value);
397
398         case offsetof(struct user_regs_struct, flags):
399                 return set_flags(child, value);
400
401 #ifdef CONFIG_X86_64
402         case offsetof(struct user_regs_struct,fs_base):
403                 if (value >= TASK_SIZE_OF(child))
404                         return -EIO;
405                 /*
406                  * When changing the segment base, use do_arch_prctl
407                  * to set either thread.fs or thread.fsindex and the
408                  * corresponding GDT slot.
409                  */
410                 if (child->thread.fs != value)
411                         return do_arch_prctl(child, ARCH_SET_FS, value);
412                 return 0;
413         case offsetof(struct user_regs_struct,gs_base):
414                 /*
415                  * Exactly the same here as the %fs handling above.
416                  */
417                 if (value >= TASK_SIZE_OF(child))
418                         return -EIO;
419                 if (child->thread.gs != value)
420                         return do_arch_prctl(child, ARCH_SET_GS, value);
421                 return 0;
422 #endif
423         }
424
425         *pt_regs_access(task_pt_regs(child), offset) = value;
426         return 0;
427 }
428
429 static unsigned long getreg(struct task_struct *task, unsigned long offset)
430 {
431         switch (offset) {
432         case offsetof(struct user_regs_struct, cs):
433         case offsetof(struct user_regs_struct, ds):
434         case offsetof(struct user_regs_struct, es):
435         case offsetof(struct user_regs_struct, fs):
436         case offsetof(struct user_regs_struct, gs):
437         case offsetof(struct user_regs_struct, ss):
438                 return get_segment_reg(task, offset);
439
440         case offsetof(struct user_regs_struct, flags):
441                 return get_flags(task);
442
443 #ifdef CONFIG_X86_64
444         case offsetof(struct user_regs_struct, fs_base): {
445                 /*
446                  * do_arch_prctl may have used a GDT slot instead of
447                  * the MSR.  To userland, it appears the same either
448                  * way, except the %fs segment selector might not be 0.
449                  */
450                 unsigned int seg = task->thread.fsindex;
451                 if (task->thread.fs != 0)
452                         return task->thread.fs;
453                 if (task == current)
454                         asm("movl %%fs,%0" : "=r" (seg));
455                 if (seg != FS_TLS_SEL)
456                         return 0;
457                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
458         }
459         case offsetof(struct user_regs_struct, gs_base): {
460                 /*
461                  * Exactly the same here as the %fs handling above.
462                  */
463                 unsigned int seg = task->thread.gsindex;
464                 if (task->thread.gs != 0)
465                         return task->thread.gs;
466                 if (task == current)
467                         asm("movl %%gs,%0" : "=r" (seg));
468                 if (seg != GS_TLS_SEL)
469                         return 0;
470                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
471         }
472 #endif
473         }
474
475         return *pt_regs_access(task_pt_regs(task), offset);
476 }
477
478 static int genregs_get(struct task_struct *target,
479                        const struct user_regset *regset,
480                        unsigned int pos, unsigned int count,
481                        void *kbuf, void __user *ubuf)
482 {
483         if (kbuf) {
484                 unsigned long *k = kbuf;
485                 while (count >= sizeof(*k)) {
486                         *k++ = getreg(target, pos);
487                         count -= sizeof(*k);
488                         pos += sizeof(*k);
489                 }
490         } else {
491                 unsigned long __user *u = ubuf;
492                 while (count >= sizeof(*u)) {
493                         if (__put_user(getreg(target, pos), u++))
494                                 return -EFAULT;
495                         count -= sizeof(*u);
496                         pos += sizeof(*u);
497                 }
498         }
499
500         return 0;
501 }
502
503 static int genregs_set(struct task_struct *target,
504                        const struct user_regset *regset,
505                        unsigned int pos, unsigned int count,
506                        const void *kbuf, const void __user *ubuf)
507 {
508         int ret = 0;
509         if (kbuf) {
510                 const unsigned long *k = kbuf;
511                 while (count >= sizeof(*k) && !ret) {
512                         ret = putreg(target, pos, *k++);
513                         count -= sizeof(*k);
514                         pos += sizeof(*k);
515                 }
516         } else {
517                 const unsigned long  __user *u = ubuf;
518                 while (count >= sizeof(*u) && !ret) {
519                         unsigned long word;
520                         ret = __get_user(word, u++);
521                         if (ret)
522                                 break;
523                         ret = putreg(target, pos, word);
524                         count -= sizeof(*u);
525                         pos += sizeof(*u);
526                 }
527         }
528         return ret;
529 }
530
531 static void ptrace_triggered(struct perf_event *bp,
532                              struct perf_sample_data *data,
533                              struct pt_regs *regs)
534 {
535         int i;
536         struct thread_struct *thread = &(current->thread);
537
538         /*
539          * Store in the virtual DR6 register the fact that the breakpoint
540          * was hit so the thread's debugger will see it.
541          */
542         for (i = 0; i < HBP_NUM; i++) {
543                 if (thread->ptrace_bps[i] == bp)
544                         break;
545         }
546
547         thread->debugreg6 |= (DR_TRAP0 << i);
548 }
549
550 /*
551  * Walk through every ptrace breakpoints for this thread and
552  * build the dr7 value on top of their attributes.
553  *
554  */
555 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
556 {
557         int i;
558         int dr7 = 0;
559         struct arch_hw_breakpoint *info;
560
561         for (i = 0; i < HBP_NUM; i++) {
562                 if (bp[i] && !bp[i]->attr.disabled) {
563                         info = counter_arch_bp(bp[i]);
564                         dr7 |= encode_dr7(i, info->len, info->type);
565                 }
566         }
567
568         return dr7;
569 }
570
571 static int
572 ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
573                          struct task_struct *tsk, int disabled)
574 {
575         int err;
576         int gen_len, gen_type;
577         struct perf_event_attr attr;
578
579         /*
580          * We should have at least an inactive breakpoint at this
581          * slot. It means the user is writing dr7 without having
582          * written the address register first
583          */
584         if (!bp)
585                 return -EINVAL;
586
587         err = arch_bp_generic_fields(len, type, &gen_len, &gen_type);
588         if (err)
589                 return err;
590
591         attr = bp->attr;
592         attr.bp_len = gen_len;
593         attr.bp_type = gen_type;
594         attr.disabled = disabled;
595
596         return modify_user_hw_breakpoint(bp, &attr);
597 }
598
599 /*
600  * Handle ptrace writes to debug register 7.
601  */
602 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
603 {
604         struct thread_struct *thread = &(tsk->thread);
605         unsigned long old_dr7;
606         int i, orig_ret = 0, rc = 0;
607         int enabled, second_pass = 0;
608         unsigned len, type;
609         struct perf_event *bp;
610
611         if (ptrace_get_breakpoints(tsk) < 0)
612                 return -ESRCH;
613
614         data &= ~DR_CONTROL_RESERVED;
615         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
616 restore:
617         /*
618          * Loop through all the hardware breakpoints, making the
619          * appropriate changes to each.
620          */
621         for (i = 0; i < HBP_NUM; i++) {
622                 enabled = decode_dr7(data, i, &len, &type);
623                 bp = thread->ptrace_bps[i];
624
625                 if (!enabled) {
626                         if (bp) {
627                                 /*
628                                  * Don't unregister the breakpoints right-away,
629                                  * unless all register_user_hw_breakpoint()
630                                  * requests have succeeded. This prevents
631                                  * any window of opportunity for debug
632                                  * register grabbing by other users.
633                                  */
634                                 if (!second_pass)
635                                         continue;
636
637                                 rc = ptrace_modify_breakpoint(bp, len, type,
638                                                               tsk, 1);
639                                 if (rc)
640                                         break;
641                         }
642                         continue;
643                 }
644
645                 rc = ptrace_modify_breakpoint(bp, len, type, tsk, 0);
646                 if (rc)
647                         break;
648         }
649         /*
650          * Make a second pass to free the remaining unused breakpoints
651          * or to restore the original breakpoints if an error occurred.
652          */
653         if (!second_pass) {
654                 second_pass = 1;
655                 if (rc < 0) {
656                         orig_ret = rc;
657                         data = old_dr7;
658                 }
659                 goto restore;
660         }
661
662         ptrace_put_breakpoints(tsk);
663
664         return ((orig_ret < 0) ? orig_ret : rc);
665 }
666
667 /*
668  * Handle PTRACE_PEEKUSR calls for the debug register area.
669  */
670 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
671 {
672         struct thread_struct *thread = &(tsk->thread);
673         unsigned long val = 0;
674
675         if (n < HBP_NUM) {
676                 struct perf_event *bp;
677
678                 if (ptrace_get_breakpoints(tsk) < 0)
679                         return -ESRCH;
680
681                 bp = thread->ptrace_bps[n];
682                 if (!bp)
683                         val = 0;
684                 else
685                         val = bp->hw.info.address;
686
687                 ptrace_put_breakpoints(tsk);
688         } else if (n == 6) {
689                 val = thread->debugreg6;
690          } else if (n == 7) {
691                 val = thread->ptrace_dr7;
692         }
693         return val;
694 }
695
696 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
697                                       unsigned long addr)
698 {
699         struct perf_event *bp;
700         struct thread_struct *t = &tsk->thread;
701         struct perf_event_attr attr;
702         int err = 0;
703
704         if (ptrace_get_breakpoints(tsk) < 0)
705                 return -ESRCH;
706
707         if (!t->ptrace_bps[nr]) {
708                 ptrace_breakpoint_init(&attr);
709                 /*
710                  * Put stub len and type to register (reserve) an inactive but
711                  * correct bp
712                  */
713                 attr.bp_addr = addr;
714                 attr.bp_len = HW_BREAKPOINT_LEN_1;
715                 attr.bp_type = HW_BREAKPOINT_W;
716                 attr.disabled = 1;
717
718                 bp = register_user_hw_breakpoint(&attr, ptrace_triggered, tsk);
719
720                 /*
721                  * CHECKME: the previous code returned -EIO if the addr wasn't
722                  * a valid task virtual addr. The new one will return -EINVAL in
723                  *  this case.
724                  * -EINVAL may be what we want for in-kernel breakpoints users,
725                  * but -EIO looks better for ptrace, since we refuse a register
726                  * writing for the user. And anyway this is the previous
727                  * behaviour.
728                  */
729                 if (IS_ERR(bp)) {
730                         err = PTR_ERR(bp);
731                         goto put;
732                 }
733
734                 t->ptrace_bps[nr] = bp;
735         } else {
736                 bp = t->ptrace_bps[nr];
737
738                 attr = bp->attr;
739                 attr.bp_addr = addr;
740                 err = modify_user_hw_breakpoint(bp, &attr);
741         }
742
743 put:
744         ptrace_put_breakpoints(tsk);
745         return err;
746 }
747
748 /*
749  * Handle PTRACE_POKEUSR calls for the debug register area.
750  */
751 int ptrace_set_debugreg(struct task_struct *tsk, int n, unsigned long val)
752 {
753         struct thread_struct *thread = &(tsk->thread);
754         int rc = 0;
755
756         /* There are no DR4 or DR5 registers */
757         if (n == 4 || n == 5)
758                 return -EIO;
759
760         if (n == 6) {
761                 thread->debugreg6 = val;
762                 goto ret_path;
763         }
764         if (n < HBP_NUM) {
765                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
766                 if (rc)
767                         return rc;
768         }
769         /* All that's left is DR7 */
770         if (n == 7) {
771                 rc = ptrace_write_dr7(tsk, val);
772                 if (!rc)
773                         thread->ptrace_dr7 = val;
774         }
775
776 ret_path:
777         return rc;
778 }
779
780 /*
781  * These access the current or another (stopped) task's io permission
782  * bitmap for debugging or core dump.
783  */
784 static int ioperm_active(struct task_struct *target,
785                          const struct user_regset *regset)
786 {
787         return target->thread.io_bitmap_max / regset->size;
788 }
789
790 static int ioperm_get(struct task_struct *target,
791                       const struct user_regset *regset,
792                       unsigned int pos, unsigned int count,
793                       void *kbuf, void __user *ubuf)
794 {
795         if (!target->thread.io_bitmap_ptr)
796                 return -ENXIO;
797
798         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
799                                    target->thread.io_bitmap_ptr,
800                                    0, IO_BITMAP_BYTES);
801 }
802
803 /*
804  * Called by kernel/ptrace.c when detaching..
805  *
806  * Make sure the single step bit is not set.
807  */
808 void ptrace_disable(struct task_struct *child)
809 {
810         user_disable_single_step(child);
811 #ifdef TIF_SYSCALL_EMU
812         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
813 #endif
814 }
815
816 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
817 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
818 #endif
819
820 long arch_ptrace(struct task_struct *child, long request,
821                  unsigned long addr, unsigned long data)
822 {
823         int ret;
824         unsigned long __user *datap = (unsigned long __user *)data;
825
826         switch (request) {
827         /* read the word at location addr in the USER area. */
828         case PTRACE_PEEKUSR: {
829                 unsigned long tmp;
830
831                 ret = -EIO;
832                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
833                         break;
834
835                 tmp = 0;  /* Default return condition */
836                 if (addr < sizeof(struct user_regs_struct))
837                         tmp = getreg(child, addr);
838                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
839                          addr <= offsetof(struct user, u_debugreg[7])) {
840                         addr -= offsetof(struct user, u_debugreg[0]);
841                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
842                 }
843                 ret = put_user(tmp, datap);
844                 break;
845         }
846
847         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
848                 ret = -EIO;
849                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
850                         break;
851
852                 if (addr < sizeof(struct user_regs_struct))
853                         ret = putreg(child, addr, data);
854                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
855                          addr <= offsetof(struct user, u_debugreg[7])) {
856                         addr -= offsetof(struct user, u_debugreg[0]);
857                         ret = ptrace_set_debugreg(child,
858                                                   addr / sizeof(data), data);
859                 }
860                 break;
861
862         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
863                 return copy_regset_to_user(child,
864                                            task_user_regset_view(current),
865                                            REGSET_GENERAL,
866                                            0, sizeof(struct user_regs_struct),
867                                            datap);
868
869         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
870                 return copy_regset_from_user(child,
871                                              task_user_regset_view(current),
872                                              REGSET_GENERAL,
873                                              0, sizeof(struct user_regs_struct),
874                                              datap);
875
876         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
877                 return copy_regset_to_user(child,
878                                            task_user_regset_view(current),
879                                            REGSET_FP,
880                                            0, sizeof(struct user_i387_struct),
881                                            datap);
882
883         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
884                 return copy_regset_from_user(child,
885                                              task_user_regset_view(current),
886                                              REGSET_FP,
887                                              0, sizeof(struct user_i387_struct),
888                                              datap);
889
890 #ifdef CONFIG_X86_32
891         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
892                 return copy_regset_to_user(child, &user_x86_32_view,
893                                            REGSET_XFP,
894                                            0, sizeof(struct user_fxsr_struct),
895                                            datap) ? -EIO : 0;
896
897         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
898                 return copy_regset_from_user(child, &user_x86_32_view,
899                                              REGSET_XFP,
900                                              0, sizeof(struct user_fxsr_struct),
901                                              datap) ? -EIO : 0;
902 #endif
903
904 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
905         case PTRACE_GET_THREAD_AREA:
906                 if ((int) addr < 0)
907                         return -EIO;
908                 ret = do_get_thread_area(child, addr,
909                                         (struct user_desc __user *)data);
910                 break;
911
912         case PTRACE_SET_THREAD_AREA:
913                 if ((int) addr < 0)
914                         return -EIO;
915                 ret = do_set_thread_area(child, addr,
916                                         (struct user_desc __user *)data, 0);
917                 break;
918 #endif
919
920 #ifdef CONFIG_X86_64
921                 /* normal 64bit interface to access TLS data.
922                    Works just like arch_prctl, except that the arguments
923                    are reversed. */
924         case PTRACE_ARCH_PRCTL:
925                 ret = do_arch_prctl(child, data, addr);
926                 break;
927 #endif
928
929         default:
930                 ret = ptrace_request(child, request, addr, data);
931                 break;
932         }
933
934         return ret;
935 }
936
937 #ifdef CONFIG_IA32_EMULATION
938
939 #include <linux/compat.h>
940 #include <linux/syscalls.h>
941 #include <asm/ia32.h>
942 #include <asm/user32.h>
943
944 #define R32(l,q)                                                        \
945         case offsetof(struct user32, regs.l):                           \
946                 regs->q = value; break
947
948 #define SEG32(rs)                                                       \
949         case offsetof(struct user32, regs.rs):                          \
950                 return set_segment_reg(child,                           \
951                                        offsetof(struct user_regs_struct, rs), \
952                                        value);                          \
953                 break
954
955 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
956 {
957         struct pt_regs *regs = task_pt_regs(child);
958
959         switch (regno) {
960
961         SEG32(cs);
962         SEG32(ds);
963         SEG32(es);
964         SEG32(fs);
965         SEG32(gs);
966         SEG32(ss);
967
968         R32(ebx, bx);
969         R32(ecx, cx);
970         R32(edx, dx);
971         R32(edi, di);
972         R32(esi, si);
973         R32(ebp, bp);
974         R32(eax, ax);
975         R32(eip, ip);
976         R32(esp, sp);
977
978         case offsetof(struct user32, regs.orig_eax):
979                 /*
980                  * A 32-bit debugger setting orig_eax means to restore
981                  * the state of the task restarting a 32-bit syscall.
982                  * Make sure we interpret the -ERESTART* codes correctly
983                  * in case the task is not actually still sitting at the
984                  * exit from a 32-bit syscall with TS_COMPAT still set.
985                  */
986                 regs->orig_ax = value;
987                 if (syscall_get_nr(child, regs) >= 0)
988                         task_thread_info(child)->status |= TS_COMPAT;
989                 break;
990
991         case offsetof(struct user32, regs.eflags):
992                 return set_flags(child, value);
993
994         case offsetof(struct user32, u_debugreg[0]) ...
995                 offsetof(struct user32, u_debugreg[7]):
996                 regno -= offsetof(struct user32, u_debugreg[0]);
997                 return ptrace_set_debugreg(child, regno / 4, value);
998
999         default:
1000                 if (regno > sizeof(struct user32) || (regno & 3))
1001                         return -EIO;
1002
1003                 /*
1004                  * Other dummy fields in the virtual user structure
1005                  * are ignored
1006                  */
1007                 break;
1008         }
1009         return 0;
1010 }
1011
1012 #undef R32
1013 #undef SEG32
1014
1015 #define R32(l,q)                                                        \
1016         case offsetof(struct user32, regs.l):                           \
1017                 *val = regs->q; break
1018
1019 #define SEG32(rs)                                                       \
1020         case offsetof(struct user32, regs.rs):                          \
1021                 *val = get_segment_reg(child,                           \
1022                                        offsetof(struct user_regs_struct, rs)); \
1023                 break
1024
1025 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1026 {
1027         struct pt_regs *regs = task_pt_regs(child);
1028
1029         switch (regno) {
1030
1031         SEG32(ds);
1032         SEG32(es);
1033         SEG32(fs);
1034         SEG32(gs);
1035
1036         R32(cs, cs);
1037         R32(ss, ss);
1038         R32(ebx, bx);
1039         R32(ecx, cx);
1040         R32(edx, dx);
1041         R32(edi, di);
1042         R32(esi, si);
1043         R32(ebp, bp);
1044         R32(eax, ax);
1045         R32(orig_eax, orig_ax);
1046         R32(eip, ip);
1047         R32(esp, sp);
1048
1049         case offsetof(struct user32, regs.eflags):
1050                 *val = get_flags(child);
1051                 break;
1052
1053         case offsetof(struct user32, u_debugreg[0]) ...
1054                 offsetof(struct user32, u_debugreg[7]):
1055                 regno -= offsetof(struct user32, u_debugreg[0]);
1056                 *val = ptrace_get_debugreg(child, regno / 4);
1057                 break;
1058
1059         default:
1060                 if (regno > sizeof(struct user32) || (regno & 3))
1061                         return -EIO;
1062
1063                 /*
1064                  * Other dummy fields in the virtual user structure
1065                  * are ignored
1066                  */
1067                 *val = 0;
1068                 break;
1069         }
1070         return 0;
1071 }
1072
1073 #undef R32
1074 #undef SEG32
1075
1076 static int genregs32_get(struct task_struct *target,
1077                          const struct user_regset *regset,
1078                          unsigned int pos, unsigned int count,
1079                          void *kbuf, void __user *ubuf)
1080 {
1081         if (kbuf) {
1082                 compat_ulong_t *k = kbuf;
1083                 while (count >= sizeof(*k)) {
1084                         getreg32(target, pos, k++);
1085                         count -= sizeof(*k);
1086                         pos += sizeof(*k);
1087                 }
1088         } else {
1089                 compat_ulong_t __user *u = ubuf;
1090                 while (count >= sizeof(*u)) {
1091                         compat_ulong_t word;
1092                         getreg32(target, pos, &word);
1093                         if (__put_user(word, u++))
1094                                 return -EFAULT;
1095                         count -= sizeof(*u);
1096                         pos += sizeof(*u);
1097                 }
1098         }
1099
1100         return 0;
1101 }
1102
1103 static int genregs32_set(struct task_struct *target,
1104                          const struct user_regset *regset,
1105                          unsigned int pos, unsigned int count,
1106                          const void *kbuf, const void __user *ubuf)
1107 {
1108         int ret = 0;
1109         if (kbuf) {
1110                 const compat_ulong_t *k = kbuf;
1111                 while (count >= sizeof(*k) && !ret) {
1112                         ret = putreg32(target, pos, *k++);
1113                         count -= sizeof(*k);
1114                         pos += sizeof(*k);
1115                 }
1116         } else {
1117                 const compat_ulong_t __user *u = ubuf;
1118                 while (count >= sizeof(*u) && !ret) {
1119                         compat_ulong_t word;
1120                         ret = __get_user(word, u++);
1121                         if (ret)
1122                                 break;
1123                         ret = putreg32(target, pos, word);
1124                         count -= sizeof(*u);
1125                         pos += sizeof(*u);
1126                 }
1127         }
1128         return ret;
1129 }
1130
1131 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1132                         compat_ulong_t caddr, compat_ulong_t cdata)
1133 {
1134         unsigned long addr = caddr;
1135         unsigned long data = cdata;
1136         void __user *datap = compat_ptr(data);
1137         int ret;
1138         __u32 val;
1139
1140         switch (request) {
1141         case PTRACE_PEEKUSR:
1142                 ret = getreg32(child, addr, &val);
1143                 if (ret == 0)
1144                         ret = put_user(val, (__u32 __user *)datap);
1145                 break;
1146
1147         case PTRACE_POKEUSR:
1148                 ret = putreg32(child, addr, data);
1149                 break;
1150
1151         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1152                 return copy_regset_to_user(child, &user_x86_32_view,
1153                                            REGSET_GENERAL,
1154                                            0, sizeof(struct user_regs_struct32),
1155                                            datap);
1156
1157         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1158                 return copy_regset_from_user(child, &user_x86_32_view,
1159                                              REGSET_GENERAL, 0,
1160                                              sizeof(struct user_regs_struct32),
1161                                              datap);
1162
1163         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1164                 return copy_regset_to_user(child, &user_x86_32_view,
1165                                            REGSET_FP, 0,
1166                                            sizeof(struct user_i387_ia32_struct),
1167                                            datap);
1168
1169         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1170                 return copy_regset_from_user(
1171                         child, &user_x86_32_view, REGSET_FP,
1172                         0, sizeof(struct user_i387_ia32_struct), datap);
1173
1174         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1175                 return copy_regset_to_user(child, &user_x86_32_view,
1176                                            REGSET_XFP, 0,
1177                                            sizeof(struct user32_fxsr_struct),
1178                                            datap);
1179
1180         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1181                 return copy_regset_from_user(child, &user_x86_32_view,
1182                                              REGSET_XFP, 0,
1183                                              sizeof(struct user32_fxsr_struct),
1184                                              datap);
1185
1186         case PTRACE_GET_THREAD_AREA:
1187         case PTRACE_SET_THREAD_AREA:
1188                 return arch_ptrace(child, request, addr, data);
1189
1190         default:
1191                 return compat_ptrace_request(child, request, addr, data);
1192         }
1193
1194         return ret;
1195 }
1196
1197 #endif  /* CONFIG_IA32_EMULATION */
1198
1199 #ifdef CONFIG_X86_64
1200
1201 static struct user_regset x86_64_regsets[] __read_mostly = {
1202         [REGSET_GENERAL] = {
1203                 .core_note_type = NT_PRSTATUS,
1204                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1205                 .size = sizeof(long), .align = sizeof(long),
1206                 .get = genregs_get, .set = genregs_set
1207         },
1208         [REGSET_FP] = {
1209                 .core_note_type = NT_PRFPREG,
1210                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1211                 .size = sizeof(long), .align = sizeof(long),
1212                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1213         },
1214         [REGSET_XSTATE] = {
1215                 .core_note_type = NT_X86_XSTATE,
1216                 .size = sizeof(u64), .align = sizeof(u64),
1217                 .active = xstateregs_active, .get = xstateregs_get,
1218                 .set = xstateregs_set
1219         },
1220         [REGSET_IOPERM64] = {
1221                 .core_note_type = NT_386_IOPERM,
1222                 .n = IO_BITMAP_LONGS,
1223                 .size = sizeof(long), .align = sizeof(long),
1224                 .active = ioperm_active, .get = ioperm_get
1225         },
1226 };
1227
1228 static const struct user_regset_view user_x86_64_view = {
1229         .name = "x86_64", .e_machine = EM_X86_64,
1230         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1231 };
1232
1233 #else  /* CONFIG_X86_32 */
1234
1235 #define user_regs_struct32      user_regs_struct
1236 #define genregs32_get           genregs_get
1237 #define genregs32_set           genregs_set
1238
1239 #define user_i387_ia32_struct   user_i387_struct
1240 #define user32_fxsr_struct      user_fxsr_struct
1241
1242 #endif  /* CONFIG_X86_64 */
1243
1244 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1245 static struct user_regset x86_32_regsets[] __read_mostly = {
1246         [REGSET_GENERAL] = {
1247                 .core_note_type = NT_PRSTATUS,
1248                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1249                 .size = sizeof(u32), .align = sizeof(u32),
1250                 .get = genregs32_get, .set = genregs32_set
1251         },
1252         [REGSET_FP] = {
1253                 .core_note_type = NT_PRFPREG,
1254                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1255                 .size = sizeof(u32), .align = sizeof(u32),
1256                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1257         },
1258         [REGSET_XFP] = {
1259                 .core_note_type = NT_PRXFPREG,
1260                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1261                 .size = sizeof(u32), .align = sizeof(u32),
1262                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1263         },
1264         [REGSET_XSTATE] = {
1265                 .core_note_type = NT_X86_XSTATE,
1266                 .size = sizeof(u64), .align = sizeof(u64),
1267                 .active = xstateregs_active, .get = xstateregs_get,
1268                 .set = xstateregs_set
1269         },
1270         [REGSET_TLS] = {
1271                 .core_note_type = NT_386_TLS,
1272                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1273                 .size = sizeof(struct user_desc),
1274                 .align = sizeof(struct user_desc),
1275                 .active = regset_tls_active,
1276                 .get = regset_tls_get, .set = regset_tls_set
1277         },
1278         [REGSET_IOPERM32] = {
1279                 .core_note_type = NT_386_IOPERM,
1280                 .n = IO_BITMAP_BYTES / sizeof(u32),
1281                 .size = sizeof(u32), .align = sizeof(u32),
1282                 .active = ioperm_active, .get = ioperm_get
1283         },
1284 };
1285
1286 static const struct user_regset_view user_x86_32_view = {
1287         .name = "i386", .e_machine = EM_386,
1288         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1289 };
1290 #endif
1291
1292 /*
1293  * This represents bytes 464..511 in the memory layout exported through
1294  * the REGSET_XSTATE interface.
1295  */
1296 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1297
1298 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1299 {
1300 #ifdef CONFIG_X86_64
1301         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1302 #endif
1303 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1304         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1305 #endif
1306         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1307 }
1308
1309 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1310 {
1311 #ifdef CONFIG_IA32_EMULATION
1312         if (test_tsk_thread_flag(task, TIF_IA32))
1313 #endif
1314 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1315                 return &user_x86_32_view;
1316 #endif
1317 #ifdef CONFIG_X86_64
1318         return &user_x86_64_view;
1319 #endif
1320 }
1321
1322 static void fill_sigtrap_info(struct task_struct *tsk,
1323                                 struct pt_regs *regs,
1324                                 int error_code, int si_code,
1325                                 struct siginfo *info)
1326 {
1327         tsk->thread.trap_no = 1;
1328         tsk->thread.error_code = error_code;
1329
1330         memset(info, 0, sizeof(*info));
1331         info->si_signo = SIGTRAP;
1332         info->si_code = si_code;
1333         info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1334 }
1335
1336 void user_single_step_siginfo(struct task_struct *tsk,
1337                                 struct pt_regs *regs,
1338                                 struct siginfo *info)
1339 {
1340         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1341 }
1342
1343 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1344                                          int error_code, int si_code)
1345 {
1346         struct siginfo info;
1347
1348         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1349         /* Send us the fake SIGTRAP */
1350         force_sig_info(SIGTRAP, &info, tsk);
1351 }
1352
1353
1354 #ifdef CONFIG_X86_32
1355 # define IS_IA32        1
1356 #elif defined CONFIG_IA32_EMULATION
1357 # define IS_IA32        is_compat_task()
1358 #else
1359 # define IS_IA32        0
1360 #endif
1361
1362 /*
1363  * We must return the syscall number to actually look up in the table.
1364  * This can be -1L to skip running any syscall at all.
1365  */
1366 long syscall_trace_enter(struct pt_regs *regs)
1367 {
1368         long ret = 0;
1369
1370         /*
1371          * If we stepped into a sysenter/syscall insn, it trapped in
1372          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1373          * If user-mode had set TF itself, then it's still clear from
1374          * do_debug() and we need to set it again to restore the user
1375          * state.  If we entered on the slow path, TF was already set.
1376          */
1377         if (test_thread_flag(TIF_SINGLESTEP))
1378                 regs->flags |= X86_EFLAGS_TF;
1379
1380         /* do the secure computing check first */
1381         secure_computing(regs->orig_ax);
1382
1383         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1384                 ret = -1L;
1385
1386         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1387             tracehook_report_syscall_entry(regs))
1388                 ret = -1L;
1389
1390         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1391                 trace_sys_enter(regs, regs->orig_ax);
1392
1393         if (unlikely(current->audit_context)) {
1394                 if (IS_IA32)
1395                         audit_syscall_entry(AUDIT_ARCH_I386,
1396                                             regs->orig_ax,
1397                                             regs->bx, regs->cx,
1398                                             regs->dx, regs->si);
1399 #ifdef CONFIG_X86_64
1400                 else
1401                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1402                                             regs->orig_ax,
1403                                             regs->di, regs->si,
1404                                             regs->dx, regs->r10);
1405 #endif
1406         }
1407
1408         return ret ?: regs->orig_ax;
1409 }
1410
1411 void syscall_trace_leave(struct pt_regs *regs)
1412 {
1413         bool step;
1414
1415         if (unlikely(current->audit_context))
1416                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1417
1418         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1419                 trace_sys_exit(regs, regs->ax);
1420
1421         /*
1422          * If TIF_SYSCALL_EMU is set, we only get here because of
1423          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1424          * We already reported this syscall instruction in
1425          * syscall_trace_enter().
1426          */
1427         step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1428                         !test_thread_flag(TIF_SYSCALL_EMU);
1429         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1430                 tracehook_report_syscall_exit(regs, step);
1431 }