Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
[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,
719                                                  NULL, tsk);
720
721                 /*
722                  * CHECKME: the previous code returned -EIO if the addr wasn't
723                  * a valid task virtual addr. The new one will return -EINVAL in
724                  *  this case.
725                  * -EINVAL may be what we want for in-kernel breakpoints users,
726                  * but -EIO looks better for ptrace, since we refuse a register
727                  * writing for the user. And anyway this is the previous
728                  * behaviour.
729                  */
730                 if (IS_ERR(bp)) {
731                         err = PTR_ERR(bp);
732                         goto put;
733                 }
734
735                 t->ptrace_bps[nr] = bp;
736         } else {
737                 bp = t->ptrace_bps[nr];
738
739                 attr = bp->attr;
740                 attr.bp_addr = addr;
741                 err = modify_user_hw_breakpoint(bp, &attr);
742         }
743
744 put:
745         ptrace_put_breakpoints(tsk);
746         return err;
747 }
748
749 /*
750  * Handle PTRACE_POKEUSR calls for the debug register area.
751  */
752 int ptrace_set_debugreg(struct task_struct *tsk, int n, unsigned long val)
753 {
754         struct thread_struct *thread = &(tsk->thread);
755         int rc = 0;
756
757         /* There are no DR4 or DR5 registers */
758         if (n == 4 || n == 5)
759                 return -EIO;
760
761         if (n == 6) {
762                 thread->debugreg6 = val;
763                 goto ret_path;
764         }
765         if (n < HBP_NUM) {
766                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
767                 if (rc)
768                         return rc;
769         }
770         /* All that's left is DR7 */
771         if (n == 7) {
772                 rc = ptrace_write_dr7(tsk, val);
773                 if (!rc)
774                         thread->ptrace_dr7 = val;
775         }
776
777 ret_path:
778         return rc;
779 }
780
781 /*
782  * These access the current or another (stopped) task's io permission
783  * bitmap for debugging or core dump.
784  */
785 static int ioperm_active(struct task_struct *target,
786                          const struct user_regset *regset)
787 {
788         return target->thread.io_bitmap_max / regset->size;
789 }
790
791 static int ioperm_get(struct task_struct *target,
792                       const struct user_regset *regset,
793                       unsigned int pos, unsigned int count,
794                       void *kbuf, void __user *ubuf)
795 {
796         if (!target->thread.io_bitmap_ptr)
797                 return -ENXIO;
798
799         return user_regset_copyout(&pos, &count, &kbuf, &ubuf,
800                                    target->thread.io_bitmap_ptr,
801                                    0, IO_BITMAP_BYTES);
802 }
803
804 /*
805  * Called by kernel/ptrace.c when detaching..
806  *
807  * Make sure the single step bit is not set.
808  */
809 void ptrace_disable(struct task_struct *child)
810 {
811         user_disable_single_step(child);
812 #ifdef TIF_SYSCALL_EMU
813         clear_tsk_thread_flag(child, TIF_SYSCALL_EMU);
814 #endif
815 }
816
817 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
818 static const struct user_regset_view user_x86_32_view; /* Initialized below. */
819 #endif
820
821 long arch_ptrace(struct task_struct *child, long request,
822                  unsigned long addr, unsigned long data)
823 {
824         int ret;
825         unsigned long __user *datap = (unsigned long __user *)data;
826
827         switch (request) {
828         /* read the word at location addr in the USER area. */
829         case PTRACE_PEEKUSR: {
830                 unsigned long tmp;
831
832                 ret = -EIO;
833                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
834                         break;
835
836                 tmp = 0;  /* Default return condition */
837                 if (addr < sizeof(struct user_regs_struct))
838                         tmp = getreg(child, addr);
839                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
840                          addr <= offsetof(struct user, u_debugreg[7])) {
841                         addr -= offsetof(struct user, u_debugreg[0]);
842                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
843                 }
844                 ret = put_user(tmp, datap);
845                 break;
846         }
847
848         case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
849                 ret = -EIO;
850                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user))
851                         break;
852
853                 if (addr < sizeof(struct user_regs_struct))
854                         ret = putreg(child, addr, data);
855                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
856                          addr <= offsetof(struct user, u_debugreg[7])) {
857                         addr -= offsetof(struct user, u_debugreg[0]);
858                         ret = ptrace_set_debugreg(child,
859                                                   addr / sizeof(data), data);
860                 }
861                 break;
862
863         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
864                 return copy_regset_to_user(child,
865                                            task_user_regset_view(current),
866                                            REGSET_GENERAL,
867                                            0, sizeof(struct user_regs_struct),
868                                            datap);
869
870         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
871                 return copy_regset_from_user(child,
872                                              task_user_regset_view(current),
873                                              REGSET_GENERAL,
874                                              0, sizeof(struct user_regs_struct),
875                                              datap);
876
877         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
878                 return copy_regset_to_user(child,
879                                            task_user_regset_view(current),
880                                            REGSET_FP,
881                                            0, sizeof(struct user_i387_struct),
882                                            datap);
883
884         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
885                 return copy_regset_from_user(child,
886                                              task_user_regset_view(current),
887                                              REGSET_FP,
888                                              0, sizeof(struct user_i387_struct),
889                                              datap);
890
891 #ifdef CONFIG_X86_32
892         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
893                 return copy_regset_to_user(child, &user_x86_32_view,
894                                            REGSET_XFP,
895                                            0, sizeof(struct user_fxsr_struct),
896                                            datap) ? -EIO : 0;
897
898         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
899                 return copy_regset_from_user(child, &user_x86_32_view,
900                                              REGSET_XFP,
901                                              0, sizeof(struct user_fxsr_struct),
902                                              datap) ? -EIO : 0;
903 #endif
904
905 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
906         case PTRACE_GET_THREAD_AREA:
907                 if ((int) addr < 0)
908                         return -EIO;
909                 ret = do_get_thread_area(child, addr,
910                                         (struct user_desc __user *)data);
911                 break;
912
913         case PTRACE_SET_THREAD_AREA:
914                 if ((int) addr < 0)
915                         return -EIO;
916                 ret = do_set_thread_area(child, addr,
917                                         (struct user_desc __user *)data, 0);
918                 break;
919 #endif
920
921 #ifdef CONFIG_X86_64
922                 /* normal 64bit interface to access TLS data.
923                    Works just like arch_prctl, except that the arguments
924                    are reversed. */
925         case PTRACE_ARCH_PRCTL:
926                 ret = do_arch_prctl(child, data, addr);
927                 break;
928 #endif
929
930         default:
931                 ret = ptrace_request(child, request, addr, data);
932                 break;
933         }
934
935         return ret;
936 }
937
938 #ifdef CONFIG_IA32_EMULATION
939
940 #include <linux/compat.h>
941 #include <linux/syscalls.h>
942 #include <asm/ia32.h>
943 #include <asm/user32.h>
944
945 #define R32(l,q)                                                        \
946         case offsetof(struct user32, regs.l):                           \
947                 regs->q = value; break
948
949 #define SEG32(rs)                                                       \
950         case offsetof(struct user32, regs.rs):                          \
951                 return set_segment_reg(child,                           \
952                                        offsetof(struct user_regs_struct, rs), \
953                                        value);                          \
954                 break
955
956 static int putreg32(struct task_struct *child, unsigned regno, u32 value)
957 {
958         struct pt_regs *regs = task_pt_regs(child);
959
960         switch (regno) {
961
962         SEG32(cs);
963         SEG32(ds);
964         SEG32(es);
965         SEG32(fs);
966         SEG32(gs);
967         SEG32(ss);
968
969         R32(ebx, bx);
970         R32(ecx, cx);
971         R32(edx, dx);
972         R32(edi, di);
973         R32(esi, si);
974         R32(ebp, bp);
975         R32(eax, ax);
976         R32(eip, ip);
977         R32(esp, sp);
978
979         case offsetof(struct user32, regs.orig_eax):
980                 /*
981                  * A 32-bit debugger setting orig_eax means to restore
982                  * the state of the task restarting a 32-bit syscall.
983                  * Make sure we interpret the -ERESTART* codes correctly
984                  * in case the task is not actually still sitting at the
985                  * exit from a 32-bit syscall with TS_COMPAT still set.
986                  */
987                 regs->orig_ax = value;
988                 if (syscall_get_nr(child, regs) >= 0)
989                         task_thread_info(child)->status |= TS_COMPAT;
990                 break;
991
992         case offsetof(struct user32, regs.eflags):
993                 return set_flags(child, value);
994
995         case offsetof(struct user32, u_debugreg[0]) ...
996                 offsetof(struct user32, u_debugreg[7]):
997                 regno -= offsetof(struct user32, u_debugreg[0]);
998                 return ptrace_set_debugreg(child, regno / 4, value);
999
1000         default:
1001                 if (regno > sizeof(struct user32) || (regno & 3))
1002                         return -EIO;
1003
1004                 /*
1005                  * Other dummy fields in the virtual user structure
1006                  * are ignored
1007                  */
1008                 break;
1009         }
1010         return 0;
1011 }
1012
1013 #undef R32
1014 #undef SEG32
1015
1016 #define R32(l,q)                                                        \
1017         case offsetof(struct user32, regs.l):                           \
1018                 *val = regs->q; break
1019
1020 #define SEG32(rs)                                                       \
1021         case offsetof(struct user32, regs.rs):                          \
1022                 *val = get_segment_reg(child,                           \
1023                                        offsetof(struct user_regs_struct, rs)); \
1024                 break
1025
1026 static int getreg32(struct task_struct *child, unsigned regno, u32 *val)
1027 {
1028         struct pt_regs *regs = task_pt_regs(child);
1029
1030         switch (regno) {
1031
1032         SEG32(ds);
1033         SEG32(es);
1034         SEG32(fs);
1035         SEG32(gs);
1036
1037         R32(cs, cs);
1038         R32(ss, ss);
1039         R32(ebx, bx);
1040         R32(ecx, cx);
1041         R32(edx, dx);
1042         R32(edi, di);
1043         R32(esi, si);
1044         R32(ebp, bp);
1045         R32(eax, ax);
1046         R32(orig_eax, orig_ax);
1047         R32(eip, ip);
1048         R32(esp, sp);
1049
1050         case offsetof(struct user32, regs.eflags):
1051                 *val = get_flags(child);
1052                 break;
1053
1054         case offsetof(struct user32, u_debugreg[0]) ...
1055                 offsetof(struct user32, u_debugreg[7]):
1056                 regno -= offsetof(struct user32, u_debugreg[0]);
1057                 *val = ptrace_get_debugreg(child, regno / 4);
1058                 break;
1059
1060         default:
1061                 if (regno > sizeof(struct user32) || (regno & 3))
1062                         return -EIO;
1063
1064                 /*
1065                  * Other dummy fields in the virtual user structure
1066                  * are ignored
1067                  */
1068                 *val = 0;
1069                 break;
1070         }
1071         return 0;
1072 }
1073
1074 #undef R32
1075 #undef SEG32
1076
1077 static int genregs32_get(struct task_struct *target,
1078                          const struct user_regset *regset,
1079                          unsigned int pos, unsigned int count,
1080                          void *kbuf, void __user *ubuf)
1081 {
1082         if (kbuf) {
1083                 compat_ulong_t *k = kbuf;
1084                 while (count >= sizeof(*k)) {
1085                         getreg32(target, pos, k++);
1086                         count -= sizeof(*k);
1087                         pos += sizeof(*k);
1088                 }
1089         } else {
1090                 compat_ulong_t __user *u = ubuf;
1091                 while (count >= sizeof(*u)) {
1092                         compat_ulong_t word;
1093                         getreg32(target, pos, &word);
1094                         if (__put_user(word, u++))
1095                                 return -EFAULT;
1096                         count -= sizeof(*u);
1097                         pos += sizeof(*u);
1098                 }
1099         }
1100
1101         return 0;
1102 }
1103
1104 static int genregs32_set(struct task_struct *target,
1105                          const struct user_regset *regset,
1106                          unsigned int pos, unsigned int count,
1107                          const void *kbuf, const void __user *ubuf)
1108 {
1109         int ret = 0;
1110         if (kbuf) {
1111                 const compat_ulong_t *k = kbuf;
1112                 while (count >= sizeof(*k) && !ret) {
1113                         ret = putreg32(target, pos, *k++);
1114                         count -= sizeof(*k);
1115                         pos += sizeof(*k);
1116                 }
1117         } else {
1118                 const compat_ulong_t __user *u = ubuf;
1119                 while (count >= sizeof(*u) && !ret) {
1120                         compat_ulong_t word;
1121                         ret = __get_user(word, u++);
1122                         if (ret)
1123                                 break;
1124                         ret = putreg32(target, pos, word);
1125                         count -= sizeof(*u);
1126                         pos += sizeof(*u);
1127                 }
1128         }
1129         return ret;
1130 }
1131
1132 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1133                         compat_ulong_t caddr, compat_ulong_t cdata)
1134 {
1135         unsigned long addr = caddr;
1136         unsigned long data = cdata;
1137         void __user *datap = compat_ptr(data);
1138         int ret;
1139         __u32 val;
1140
1141         switch (request) {
1142         case PTRACE_PEEKUSR:
1143                 ret = getreg32(child, addr, &val);
1144                 if (ret == 0)
1145                         ret = put_user(val, (__u32 __user *)datap);
1146                 break;
1147
1148         case PTRACE_POKEUSR:
1149                 ret = putreg32(child, addr, data);
1150                 break;
1151
1152         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1153                 return copy_regset_to_user(child, &user_x86_32_view,
1154                                            REGSET_GENERAL,
1155                                            0, sizeof(struct user_regs_struct32),
1156                                            datap);
1157
1158         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1159                 return copy_regset_from_user(child, &user_x86_32_view,
1160                                              REGSET_GENERAL, 0,
1161                                              sizeof(struct user_regs_struct32),
1162                                              datap);
1163
1164         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1165                 return copy_regset_to_user(child, &user_x86_32_view,
1166                                            REGSET_FP, 0,
1167                                            sizeof(struct user_i387_ia32_struct),
1168                                            datap);
1169
1170         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1171                 return copy_regset_from_user(
1172                         child, &user_x86_32_view, REGSET_FP,
1173                         0, sizeof(struct user_i387_ia32_struct), datap);
1174
1175         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1176                 return copy_regset_to_user(child, &user_x86_32_view,
1177                                            REGSET_XFP, 0,
1178                                            sizeof(struct user32_fxsr_struct),
1179                                            datap);
1180
1181         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1182                 return copy_regset_from_user(child, &user_x86_32_view,
1183                                              REGSET_XFP, 0,
1184                                              sizeof(struct user32_fxsr_struct),
1185                                              datap);
1186
1187         case PTRACE_GET_THREAD_AREA:
1188         case PTRACE_SET_THREAD_AREA:
1189                 return arch_ptrace(child, request, addr, data);
1190
1191         default:
1192                 return compat_ptrace_request(child, request, addr, data);
1193         }
1194
1195         return ret;
1196 }
1197
1198 #endif  /* CONFIG_IA32_EMULATION */
1199
1200 #ifdef CONFIG_X86_64
1201
1202 static struct user_regset x86_64_regsets[] __read_mostly = {
1203         [REGSET_GENERAL] = {
1204                 .core_note_type = NT_PRSTATUS,
1205                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1206                 .size = sizeof(long), .align = sizeof(long),
1207                 .get = genregs_get, .set = genregs_set
1208         },
1209         [REGSET_FP] = {
1210                 .core_note_type = NT_PRFPREG,
1211                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1212                 .size = sizeof(long), .align = sizeof(long),
1213                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1214         },
1215         [REGSET_XSTATE] = {
1216                 .core_note_type = NT_X86_XSTATE,
1217                 .size = sizeof(u64), .align = sizeof(u64),
1218                 .active = xstateregs_active, .get = xstateregs_get,
1219                 .set = xstateregs_set
1220         },
1221         [REGSET_IOPERM64] = {
1222                 .core_note_type = NT_386_IOPERM,
1223                 .n = IO_BITMAP_LONGS,
1224                 .size = sizeof(long), .align = sizeof(long),
1225                 .active = ioperm_active, .get = ioperm_get
1226         },
1227 };
1228
1229 static const struct user_regset_view user_x86_64_view = {
1230         .name = "x86_64", .e_machine = EM_X86_64,
1231         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1232 };
1233
1234 #else  /* CONFIG_X86_32 */
1235
1236 #define user_regs_struct32      user_regs_struct
1237 #define genregs32_get           genregs_get
1238 #define genregs32_set           genregs_set
1239
1240 #define user_i387_ia32_struct   user_i387_struct
1241 #define user32_fxsr_struct      user_fxsr_struct
1242
1243 #endif  /* CONFIG_X86_64 */
1244
1245 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1246 static struct user_regset x86_32_regsets[] __read_mostly = {
1247         [REGSET_GENERAL] = {
1248                 .core_note_type = NT_PRSTATUS,
1249                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1250                 .size = sizeof(u32), .align = sizeof(u32),
1251                 .get = genregs32_get, .set = genregs32_set
1252         },
1253         [REGSET_FP] = {
1254                 .core_note_type = NT_PRFPREG,
1255                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1256                 .size = sizeof(u32), .align = sizeof(u32),
1257                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1258         },
1259         [REGSET_XFP] = {
1260                 .core_note_type = NT_PRXFPREG,
1261                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1262                 .size = sizeof(u32), .align = sizeof(u32),
1263                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1264         },
1265         [REGSET_XSTATE] = {
1266                 .core_note_type = NT_X86_XSTATE,
1267                 .size = sizeof(u64), .align = sizeof(u64),
1268                 .active = xstateregs_active, .get = xstateregs_get,
1269                 .set = xstateregs_set
1270         },
1271         [REGSET_TLS] = {
1272                 .core_note_type = NT_386_TLS,
1273                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1274                 .size = sizeof(struct user_desc),
1275                 .align = sizeof(struct user_desc),
1276                 .active = regset_tls_active,
1277                 .get = regset_tls_get, .set = regset_tls_set
1278         },
1279         [REGSET_IOPERM32] = {
1280                 .core_note_type = NT_386_IOPERM,
1281                 .n = IO_BITMAP_BYTES / sizeof(u32),
1282                 .size = sizeof(u32), .align = sizeof(u32),
1283                 .active = ioperm_active, .get = ioperm_get
1284         },
1285 };
1286
1287 static const struct user_regset_view user_x86_32_view = {
1288         .name = "i386", .e_machine = EM_386,
1289         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1290 };
1291 #endif
1292
1293 /*
1294  * This represents bytes 464..511 in the memory layout exported through
1295  * the REGSET_XSTATE interface.
1296  */
1297 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1298
1299 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1300 {
1301 #ifdef CONFIG_X86_64
1302         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1303 #endif
1304 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1305         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1306 #endif
1307         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1308 }
1309
1310 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1311 {
1312 #ifdef CONFIG_IA32_EMULATION
1313         if (test_tsk_thread_flag(task, TIF_IA32))
1314 #endif
1315 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1316                 return &user_x86_32_view;
1317 #endif
1318 #ifdef CONFIG_X86_64
1319         return &user_x86_64_view;
1320 #endif
1321 }
1322
1323 static void fill_sigtrap_info(struct task_struct *tsk,
1324                                 struct pt_regs *regs,
1325                                 int error_code, int si_code,
1326                                 struct siginfo *info)
1327 {
1328         tsk->thread.trap_no = 1;
1329         tsk->thread.error_code = error_code;
1330
1331         memset(info, 0, sizeof(*info));
1332         info->si_signo = SIGTRAP;
1333         info->si_code = si_code;
1334         info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1335 }
1336
1337 void user_single_step_siginfo(struct task_struct *tsk,
1338                                 struct pt_regs *regs,
1339                                 struct siginfo *info)
1340 {
1341         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1342 }
1343
1344 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1345                                          int error_code, int si_code)
1346 {
1347         struct siginfo info;
1348
1349         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1350         /* Send us the fake SIGTRAP */
1351         force_sig_info(SIGTRAP, &info, tsk);
1352 }
1353
1354
1355 #ifdef CONFIG_X86_32
1356 # define IS_IA32        1
1357 #elif defined CONFIG_IA32_EMULATION
1358 # define IS_IA32        is_compat_task()
1359 #else
1360 # define IS_IA32        0
1361 #endif
1362
1363 /*
1364  * We must return the syscall number to actually look up in the table.
1365  * This can be -1L to skip running any syscall at all.
1366  */
1367 long syscall_trace_enter(struct pt_regs *regs)
1368 {
1369         long ret = 0;
1370
1371         /*
1372          * If we stepped into a sysenter/syscall insn, it trapped in
1373          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1374          * If user-mode had set TF itself, then it's still clear from
1375          * do_debug() and we need to set it again to restore the user
1376          * state.  If we entered on the slow path, TF was already set.
1377          */
1378         if (test_thread_flag(TIF_SINGLESTEP))
1379                 regs->flags |= X86_EFLAGS_TF;
1380
1381         /* do the secure computing check first */
1382         secure_computing(regs->orig_ax);
1383
1384         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1385                 ret = -1L;
1386
1387         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1388             tracehook_report_syscall_entry(regs))
1389                 ret = -1L;
1390
1391         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1392                 trace_sys_enter(regs, regs->orig_ax);
1393
1394         if (unlikely(current->audit_context)) {
1395                 if (IS_IA32)
1396                         audit_syscall_entry(AUDIT_ARCH_I386,
1397                                             regs->orig_ax,
1398                                             regs->bx, regs->cx,
1399                                             regs->dx, regs->si);
1400 #ifdef CONFIG_X86_64
1401                 else
1402                         audit_syscall_entry(AUDIT_ARCH_X86_64,
1403                                             regs->orig_ax,
1404                                             regs->di, regs->si,
1405                                             regs->dx, regs->r10);
1406 #endif
1407         }
1408
1409         return ret ?: regs->orig_ax;
1410 }
1411
1412 void syscall_trace_leave(struct pt_regs *regs)
1413 {
1414         bool step;
1415
1416         if (unlikely(current->audit_context))
1417                 audit_syscall_exit(AUDITSC_RESULT(regs->ax), regs->ax);
1418
1419         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1420                 trace_sys_exit(regs, regs->ax);
1421
1422         /*
1423          * If TIF_SYSCALL_EMU is set, we only get here because of
1424          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1425          * We already reported this syscall instruction in
1426          * syscall_trace_enter().
1427          */
1428         step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1429                         !test_thread_flag(TIF_SYSCALL_EMU);
1430         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1431                 tracehook_report_syscall_exit(regs, step);
1432 }