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Linux/arch/x86/kernel/ptrace.c

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  1 /* By Ross Biro 1/23/92 */
  2 /*
  3  * Pentium III FXSR, SSE support
  4  *      Gareth Hughes <gareth@valinux.com>, May 2000
  5  */
  6 
  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 #include <linux/rcupdate.h>
 25 #include <linux/export.h>
 26 #include <linux/context_tracking.h>
 27 
 28 #include <asm/uaccess.h>
 29 #include <asm/pgtable.h>
 30 #include <asm/processor.h>
 31 #include <asm/i387.h>
 32 #include <asm/fpu-internal.h>
 33 #include <asm/debugreg.h>
 34 #include <asm/ldt.h>
 35 #include <asm/desc.h>
 36 #include <asm/prctl.h>
 37 #include <asm/proto.h>
 38 #include <asm/hw_breakpoint.h>
 39 #include <asm/traps.h>
 40 
 41 #include "tls.h"
 42 
 43 #define CREATE_TRACE_POINTS
 44 #include <trace/events/syscalls.h>
 45 
 46 enum x86_regset {
 47         REGSET_GENERAL,
 48         REGSET_FP,
 49         REGSET_XFP,
 50         REGSET_IOPERM64 = REGSET_XFP,
 51         REGSET_XSTATE,
 52         REGSET_TLS,
 53         REGSET_IOPERM32,
 54 };
 55 
 56 struct pt_regs_offset {
 57         const char *name;
 58         int offset;
 59 };
 60 
 61 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
 62 #define REG_OFFSET_END {.name = NULL, .offset = 0}
 63 
 64 static const struct pt_regs_offset regoffset_table[] = {
 65 #ifdef CONFIG_X86_64
 66         REG_OFFSET_NAME(r15),
 67         REG_OFFSET_NAME(r14),
 68         REG_OFFSET_NAME(r13),
 69         REG_OFFSET_NAME(r12),
 70         REG_OFFSET_NAME(r11),
 71         REG_OFFSET_NAME(r10),
 72         REG_OFFSET_NAME(r9),
 73         REG_OFFSET_NAME(r8),
 74 #endif
 75         REG_OFFSET_NAME(bx),
 76         REG_OFFSET_NAME(cx),
 77         REG_OFFSET_NAME(dx),
 78         REG_OFFSET_NAME(si),
 79         REG_OFFSET_NAME(di),
 80         REG_OFFSET_NAME(bp),
 81         REG_OFFSET_NAME(ax),
 82 #ifdef CONFIG_X86_32
 83         REG_OFFSET_NAME(ds),
 84         REG_OFFSET_NAME(es),
 85         REG_OFFSET_NAME(fs),
 86         REG_OFFSET_NAME(gs),
 87 #endif
 88         REG_OFFSET_NAME(orig_ax),
 89         REG_OFFSET_NAME(ip),
 90         REG_OFFSET_NAME(cs),
 91         REG_OFFSET_NAME(flags),
 92         REG_OFFSET_NAME(sp),
 93         REG_OFFSET_NAME(ss),
 94         REG_OFFSET_END,
 95 };
 96 
 97 /**
 98  * regs_query_register_offset() - query register offset from its name
 99  * @name:       the name of a register
100  *
101  * regs_query_register_offset() returns the offset of a register in struct
102  * pt_regs from its name. If the name is invalid, this returns -EINVAL;
103  */
104 int regs_query_register_offset(const char *name)
105 {
106         const struct pt_regs_offset *roff;
107         for (roff = regoffset_table; roff->name != NULL; roff++)
108                 if (!strcmp(roff->name, name))
109                         return roff->offset;
110         return -EINVAL;
111 }
112 
113 /**
114  * regs_query_register_name() - query register name from its offset
115  * @offset:     the offset of a register in struct pt_regs.
116  *
117  * regs_query_register_name() returns the name of a register from its
118  * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
119  */
120 const char *regs_query_register_name(unsigned int offset)
121 {
122         const struct pt_regs_offset *roff;
123         for (roff = regoffset_table; roff->name != NULL; roff++)
124                 if (roff->offset == offset)
125                         return roff->name;
126         return NULL;
127 }
128 
129 static const int arg_offs_table[] = {
130 #ifdef CONFIG_X86_32
131         [0] = offsetof(struct pt_regs, ax),
132         [1] = offsetof(struct pt_regs, dx),
133         [2] = offsetof(struct pt_regs, cx)
134 #else /* CONFIG_X86_64 */
135         [0] = offsetof(struct pt_regs, di),
136         [1] = offsetof(struct pt_regs, si),
137         [2] = offsetof(struct pt_regs, dx),
138         [3] = offsetof(struct pt_regs, cx),
139         [4] = offsetof(struct pt_regs, r8),
140         [5] = offsetof(struct pt_regs, r9)
141 #endif
142 };
143 
144 /*
145  * does not yet catch signals sent when the child dies.
146  * in exit.c or in signal.c.
147  */
148 
149 /*
150  * Determines which flags the user has access to [1 = access, 0 = no access].
151  */
152 #define FLAG_MASK_32            ((unsigned long)                        \
153                                  (X86_EFLAGS_CF | X86_EFLAGS_PF |       \
154                                   X86_EFLAGS_AF | X86_EFLAGS_ZF |       \
155                                   X86_EFLAGS_SF | X86_EFLAGS_TF |       \
156                                   X86_EFLAGS_DF | X86_EFLAGS_OF |       \
157                                   X86_EFLAGS_RF | X86_EFLAGS_AC))
158 
159 /*
160  * Determines whether a value may be installed in a segment register.
161  */
162 static inline bool invalid_selector(u16 value)
163 {
164         return unlikely(value != 0 && (value & SEGMENT_RPL_MASK) != USER_RPL);
165 }
166 
167 #ifdef CONFIG_X86_32
168 
169 #define FLAG_MASK               FLAG_MASK_32
170 
171 /*
172  * X86_32 CPUs don't save ss and esp if the CPU is already in kernel mode
173  * when it traps.  The previous stack will be directly underneath the saved
174  * registers, and 'sp/ss' won't even have been saved. Thus the '&regs->sp'.
175  *
176  * Now, if the stack is empty, '&regs->sp' is out of range. In this
177  * case we try to take the previous stack. To always return a non-null
178  * stack pointer we fall back to regs as stack if no previous stack
179  * exists.
180  *
181  * This is valid only for kernel mode traps.
182  */
183 unsigned long kernel_stack_pointer(struct pt_regs *regs)
184 {
185         unsigned long context = (unsigned long)regs & ~(THREAD_SIZE - 1);
186         unsigned long sp = (unsigned long)&regs->sp;
187         struct thread_info *tinfo;
188 
189         if (context == (sp & ~(THREAD_SIZE - 1)))
190                 return sp;
191 
192         tinfo = (struct thread_info *)context;
193         if (tinfo->previous_esp)
194                 return tinfo->previous_esp;
195 
196         return (unsigned long)regs;
197 }
198 EXPORT_SYMBOL_GPL(kernel_stack_pointer);
199 
200 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long regno)
201 {
202         BUILD_BUG_ON(offsetof(struct pt_regs, bx) != 0);
203         return &regs->bx + (regno >> 2);
204 }
205 
206 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
207 {
208         /*
209          * Returning the value truncates it to 16 bits.
210          */
211         unsigned int retval;
212         if (offset != offsetof(struct user_regs_struct, gs))
213                 retval = *pt_regs_access(task_pt_regs(task), offset);
214         else {
215                 if (task == current)
216                         retval = get_user_gs(task_pt_regs(task));
217                 else
218                         retval = task_user_gs(task);
219         }
220         return retval;
221 }
222 
223 static int set_segment_reg(struct task_struct *task,
224                            unsigned long offset, u16 value)
225 {
226         /*
227          * The value argument was already truncated to 16 bits.
228          */
229         if (invalid_selector(value))
230                 return -EIO;
231 
232         /*
233          * For %cs and %ss we cannot permit a null selector.
234          * We can permit a bogus selector as long as it has USER_RPL.
235          * Null selectors are fine for other segment registers, but
236          * we will never get back to user mode with invalid %cs or %ss
237          * and will take the trap in iret instead.  Much code relies
238          * on user_mode() to distinguish a user trap frame (which can
239          * safely use invalid selectors) from a kernel trap frame.
240          */
241         switch (offset) {
242         case offsetof(struct user_regs_struct, cs):
243         case offsetof(struct user_regs_struct, ss):
244                 if (unlikely(value == 0))
245                         return -EIO;
246 
247         default:
248                 *pt_regs_access(task_pt_regs(task), offset) = value;
249                 break;
250 
251         case offsetof(struct user_regs_struct, gs):
252                 if (task == current)
253                         set_user_gs(task_pt_regs(task), value);
254                 else
255                         task_user_gs(task) = value;
256         }
257 
258         return 0;
259 }
260 
261 #else  /* CONFIG_X86_64 */
262 
263 #define FLAG_MASK               (FLAG_MASK_32 | X86_EFLAGS_NT)
264 
265 static unsigned long *pt_regs_access(struct pt_regs *regs, unsigned long offset)
266 {
267         BUILD_BUG_ON(offsetof(struct pt_regs, r15) != 0);
268         return &regs->r15 + (offset / sizeof(regs->r15));
269 }
270 
271 static u16 get_segment_reg(struct task_struct *task, unsigned long offset)
272 {
273         /*
274          * Returning the value truncates it to 16 bits.
275          */
276         unsigned int seg;
277 
278         switch (offset) {
279         case offsetof(struct user_regs_struct, fs):
280                 if (task == current) {
281                         /* Older gas can't assemble movq %?s,%r?? */
282                         asm("movl %%fs,%0" : "=r" (seg));
283                         return seg;
284                 }
285                 return task->thread.fsindex;
286         case offsetof(struct user_regs_struct, gs):
287                 if (task == current) {
288                         asm("movl %%gs,%0" : "=r" (seg));
289                         return seg;
290                 }
291                 return task->thread.gsindex;
292         case offsetof(struct user_regs_struct, ds):
293                 if (task == current) {
294                         asm("movl %%ds,%0" : "=r" (seg));
295                         return seg;
296                 }
297                 return task->thread.ds;
298         case offsetof(struct user_regs_struct, es):
299                 if (task == current) {
300                         asm("movl %%es,%0" : "=r" (seg));
301                         return seg;
302                 }
303                 return task->thread.es;
304 
305         case offsetof(struct user_regs_struct, cs):
306         case offsetof(struct user_regs_struct, ss):
307                 break;
308         }
309         return *pt_regs_access(task_pt_regs(task), offset);
310 }
311 
312 static int set_segment_reg(struct task_struct *task,
313                            unsigned long offset, u16 value)
314 {
315         /*
316          * The value argument was already truncated to 16 bits.
317          */
318         if (invalid_selector(value))
319                 return -EIO;
320 
321         switch (offset) {
322         case offsetof(struct user_regs_struct,fs):
323                 /*
324                  * If this is setting fs as for normal 64-bit use but
325                  * setting fs_base has implicitly changed it, leave it.
326                  */
327                 if ((value == FS_TLS_SEL && task->thread.fsindex == 0 &&
328                      task->thread.fs != 0) ||
329                     (value == 0 && task->thread.fsindex == FS_TLS_SEL &&
330                      task->thread.fs == 0))
331                         break;
332                 task->thread.fsindex = value;
333                 if (task == current)
334                         loadsegment(fs, task->thread.fsindex);
335                 break;
336         case offsetof(struct user_regs_struct,gs):
337                 /*
338                  * If this is setting gs as for normal 64-bit use but
339                  * setting gs_base has implicitly changed it, leave it.
340                  */
341                 if ((value == GS_TLS_SEL && task->thread.gsindex == 0 &&
342                      task->thread.gs != 0) ||
343                     (value == 0 && task->thread.gsindex == GS_TLS_SEL &&
344                      task->thread.gs == 0))
345                         break;
346                 task->thread.gsindex = value;
347                 if (task == current)
348                         load_gs_index(task->thread.gsindex);
349                 break;
350         case offsetof(struct user_regs_struct,ds):
351                 task->thread.ds = value;
352                 if (task == current)
353                         loadsegment(ds, task->thread.ds);
354                 break;
355         case offsetof(struct user_regs_struct,es):
356                 task->thread.es = value;
357                 if (task == current)
358                         loadsegment(es, task->thread.es);
359                 break;
360 
361                 /*
362                  * Can't actually change these in 64-bit mode.
363                  */
364         case offsetof(struct user_regs_struct,cs):
365                 if (unlikely(value == 0))
366                         return -EIO;
367 #ifdef CONFIG_IA32_EMULATION
368                 if (test_tsk_thread_flag(task, TIF_IA32))
369                         task_pt_regs(task)->cs = value;
370 #endif
371                 break;
372         case offsetof(struct user_regs_struct,ss):
373                 if (unlikely(value == 0))
374                         return -EIO;
375 #ifdef CONFIG_IA32_EMULATION
376                 if (test_tsk_thread_flag(task, TIF_IA32))
377                         task_pt_regs(task)->ss = value;
378 #endif
379                 break;
380         }
381 
382         return 0;
383 }
384 
385 #endif  /* CONFIG_X86_32 */
386 
387 static unsigned long get_flags(struct task_struct *task)
388 {
389         unsigned long retval = task_pt_regs(task)->flags;
390 
391         /*
392          * If the debugger set TF, hide it from the readout.
393          */
394         if (test_tsk_thread_flag(task, TIF_FORCED_TF))
395                 retval &= ~X86_EFLAGS_TF;
396 
397         return retval;
398 }
399 
400 static int set_flags(struct task_struct *task, unsigned long value)
401 {
402         struct pt_regs *regs = task_pt_regs(task);
403 
404         /*
405          * If the user value contains TF, mark that
406          * it was not "us" (the debugger) that set it.
407          * If not, make sure it stays set if we had.
408          */
409         if (value & X86_EFLAGS_TF)
410                 clear_tsk_thread_flag(task, TIF_FORCED_TF);
411         else if (test_tsk_thread_flag(task, TIF_FORCED_TF))
412                 value |= X86_EFLAGS_TF;
413 
414         regs->flags = (regs->flags & ~FLAG_MASK) | (value & FLAG_MASK);
415 
416         return 0;
417 }
418 
419 static int putreg(struct task_struct *child,
420                   unsigned long offset, unsigned long value)
421 {
422         switch (offset) {
423         case offsetof(struct user_regs_struct, cs):
424         case offsetof(struct user_regs_struct, ds):
425         case offsetof(struct user_regs_struct, es):
426         case offsetof(struct user_regs_struct, fs):
427         case offsetof(struct user_regs_struct, gs):
428         case offsetof(struct user_regs_struct, ss):
429                 return set_segment_reg(child, offset, value);
430 
431         case offsetof(struct user_regs_struct, flags):
432                 return set_flags(child, value);
433 
434 #ifdef CONFIG_X86_64
435         case offsetof(struct user_regs_struct,fs_base):
436                 if (value >= TASK_SIZE_OF(child))
437                         return -EIO;
438                 /*
439                  * When changing the segment base, use do_arch_prctl
440                  * to set either thread.fs or thread.fsindex and the
441                  * corresponding GDT slot.
442                  */
443                 if (child->thread.fs != value)
444                         return do_arch_prctl(child, ARCH_SET_FS, value);
445                 return 0;
446         case offsetof(struct user_regs_struct,gs_base):
447                 /*
448                  * Exactly the same here as the %fs handling above.
449                  */
450                 if (value >= TASK_SIZE_OF(child))
451                         return -EIO;
452                 if (child->thread.gs != value)
453                         return do_arch_prctl(child, ARCH_SET_GS, value);
454                 return 0;
455 #endif
456         }
457 
458         *pt_regs_access(task_pt_regs(child), offset) = value;
459         return 0;
460 }
461 
462 static unsigned long getreg(struct task_struct *task, unsigned long offset)
463 {
464         switch (offset) {
465         case offsetof(struct user_regs_struct, cs):
466         case offsetof(struct user_regs_struct, ds):
467         case offsetof(struct user_regs_struct, es):
468         case offsetof(struct user_regs_struct, fs):
469         case offsetof(struct user_regs_struct, gs):
470         case offsetof(struct user_regs_struct, ss):
471                 return get_segment_reg(task, offset);
472 
473         case offsetof(struct user_regs_struct, flags):
474                 return get_flags(task);
475 
476 #ifdef CONFIG_X86_64
477         case offsetof(struct user_regs_struct, fs_base): {
478                 /*
479                  * do_arch_prctl may have used a GDT slot instead of
480                  * the MSR.  To userland, it appears the same either
481                  * way, except the %fs segment selector might not be 0.
482                  */
483                 unsigned int seg = task->thread.fsindex;
484                 if (task->thread.fs != 0)
485                         return task->thread.fs;
486                 if (task == current)
487                         asm("movl %%fs,%0" : "=r" (seg));
488                 if (seg != FS_TLS_SEL)
489                         return 0;
490                 return get_desc_base(&task->thread.tls_array[FS_TLS]);
491         }
492         case offsetof(struct user_regs_struct, gs_base): {
493                 /*
494                  * Exactly the same here as the %fs handling above.
495                  */
496                 unsigned int seg = task->thread.gsindex;
497                 if (task->thread.gs != 0)
498                         return task->thread.gs;
499                 if (task == current)
500                         asm("movl %%gs,%0" : "=r" (seg));
501                 if (seg != GS_TLS_SEL)
502                         return 0;
503                 return get_desc_base(&task->thread.tls_array[GS_TLS]);
504         }
505 #endif
506         }
507 
508         return *pt_regs_access(task_pt_regs(task), offset);
509 }
510 
511 static int genregs_get(struct task_struct *target,
512                        const struct user_regset *regset,
513                        unsigned int pos, unsigned int count,
514                        void *kbuf, void __user *ubuf)
515 {
516         if (kbuf) {
517                 unsigned long *k = kbuf;
518                 while (count >= sizeof(*k)) {
519                         *k++ = getreg(target, pos);
520                         count -= sizeof(*k);
521                         pos += sizeof(*k);
522                 }
523         } else {
524                 unsigned long __user *u = ubuf;
525                 while (count >= sizeof(*u)) {
526                         if (__put_user(getreg(target, pos), u++))
527                                 return -EFAULT;
528                         count -= sizeof(*u);
529                         pos += sizeof(*u);
530                 }
531         }
532 
533         return 0;
534 }
535 
536 static int genregs_set(struct task_struct *target,
537                        const struct user_regset *regset,
538                        unsigned int pos, unsigned int count,
539                        const void *kbuf, const void __user *ubuf)
540 {
541         int ret = 0;
542         if (kbuf) {
543                 const unsigned long *k = kbuf;
544                 while (count >= sizeof(*k) && !ret) {
545                         ret = putreg(target, pos, *k++);
546                         count -= sizeof(*k);
547                         pos += sizeof(*k);
548                 }
549         } else {
550                 const unsigned long  __user *u = ubuf;
551                 while (count >= sizeof(*u) && !ret) {
552                         unsigned long word;
553                         ret = __get_user(word, u++);
554                         if (ret)
555                                 break;
556                         ret = putreg(target, pos, word);
557                         count -= sizeof(*u);
558                         pos += sizeof(*u);
559                 }
560         }
561         return ret;
562 }
563 
564 static void ptrace_triggered(struct perf_event *bp,
565                              struct perf_sample_data *data,
566                              struct pt_regs *regs)
567 {
568         int i;
569         struct thread_struct *thread = &(current->thread);
570 
571         /*
572          * Store in the virtual DR6 register the fact that the breakpoint
573          * was hit so the thread's debugger will see it.
574          */
575         for (i = 0; i < HBP_NUM; i++) {
576                 if (thread->ptrace_bps[i] == bp)
577                         break;
578         }
579 
580         thread->debugreg6 |= (DR_TRAP0 << i);
581 }
582 
583 /*
584  * Walk through every ptrace breakpoints for this thread and
585  * build the dr7 value on top of their attributes.
586  *
587  */
588 static unsigned long ptrace_get_dr7(struct perf_event *bp[])
589 {
590         int i;
591         int dr7 = 0;
592         struct arch_hw_breakpoint *info;
593 
594         for (i = 0; i < HBP_NUM; i++) {
595                 if (bp[i] && !bp[i]->attr.disabled) {
596                         info = counter_arch_bp(bp[i]);
597                         dr7 |= encode_dr7(i, info->len, info->type);
598                 }
599         }
600 
601         return dr7;
602 }
603 
604 static int ptrace_fill_bp_fields(struct perf_event_attr *attr,
605                                         int len, int type, bool disabled)
606 {
607         int err, bp_len, bp_type;
608 
609         err = arch_bp_generic_fields(len, type, &bp_len, &bp_type);
610         if (!err) {
611                 attr->bp_len = bp_len;
612                 attr->bp_type = bp_type;
613                 attr->disabled = disabled;
614         }
615 
616         return err;
617 }
618 
619 static struct perf_event *
620 ptrace_register_breakpoint(struct task_struct *tsk, int len, int type,
621                                 unsigned long addr, bool disabled)
622 {
623         struct perf_event_attr attr;
624         int err;
625 
626         ptrace_breakpoint_init(&attr);
627         attr.bp_addr = addr;
628 
629         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
630         if (err)
631                 return ERR_PTR(err);
632 
633         return register_user_hw_breakpoint(&attr, ptrace_triggered,
634                                                  NULL, tsk);
635 }
636 
637 static int ptrace_modify_breakpoint(struct perf_event *bp, int len, int type,
638                                         int disabled)
639 {
640         struct perf_event_attr attr = bp->attr;
641         int err;
642 
643         err = ptrace_fill_bp_fields(&attr, len, type, disabled);
644         if (err)
645                 return err;
646 
647         return modify_user_hw_breakpoint(bp, &attr);
648 }
649 
650 /*
651  * Handle ptrace writes to debug register 7.
652  */
653 static int ptrace_write_dr7(struct task_struct *tsk, unsigned long data)
654 {
655         struct thread_struct *thread = &tsk->thread;
656         unsigned long old_dr7;
657         bool second_pass = false;
658         int i, rc, ret = 0;
659 
660         data &= ~DR_CONTROL_RESERVED;
661         old_dr7 = ptrace_get_dr7(thread->ptrace_bps);
662 
663 restore:
664         rc = 0;
665         for (i = 0; i < HBP_NUM; i++) {
666                 unsigned len, type;
667                 bool disabled = !decode_dr7(data, i, &len, &type);
668                 struct perf_event *bp = thread->ptrace_bps[i];
669 
670                 if (!bp) {
671                         if (disabled)
672                                 continue;
673 
674                         bp = ptrace_register_breakpoint(tsk,
675                                         len, type, 0, disabled);
676                         if (IS_ERR(bp)) {
677                                 rc = PTR_ERR(bp);
678                                 break;
679                         }
680 
681                         thread->ptrace_bps[i] = bp;
682                         continue;
683                 }
684 
685                 rc = ptrace_modify_breakpoint(bp, len, type, disabled);
686                 if (rc)
687                         break;
688         }
689 
690         /* Restore if the first pass failed, second_pass shouldn't fail. */
691         if (rc && !WARN_ON(second_pass)) {
692                 ret = rc;
693                 data = old_dr7;
694                 second_pass = true;
695                 goto restore;
696         }
697 
698         return ret;
699 }
700 
701 /*
702  * Handle PTRACE_PEEKUSR calls for the debug register area.
703  */
704 static unsigned long ptrace_get_debugreg(struct task_struct *tsk, int n)
705 {
706         struct thread_struct *thread = &tsk->thread;
707         unsigned long val = 0;
708 
709         if (n < HBP_NUM) {
710                 struct perf_event *bp = thread->ptrace_bps[n];
711 
712                 if (bp)
713                         val = bp->hw.info.address;
714         } else if (n == 6) {
715                 val = thread->debugreg6;
716         } else if (n == 7) {
717                 val = thread->ptrace_dr7;
718         }
719         return val;
720 }
721 
722 static int ptrace_set_breakpoint_addr(struct task_struct *tsk, int nr,
723                                       unsigned long addr)
724 {
725         struct thread_struct *t = &tsk->thread;
726         struct perf_event *bp = t->ptrace_bps[nr];
727         int err = 0;
728 
729         if (!bp) {
730                 /*
731                  * Put stub len and type to create an inactive but correct bp.
732                  *
733                  * CHECKME: the previous code returned -EIO if the addr wasn't
734                  * a valid task virtual addr. The new one will return -EINVAL in
735                  *  this case.
736                  * -EINVAL may be what we want for in-kernel breakpoints users,
737                  * but -EIO looks better for ptrace, since we refuse a register
738                  * writing for the user. And anyway this is the previous
739                  * behaviour.
740                  */
741                 bp = ptrace_register_breakpoint(tsk,
742                                 X86_BREAKPOINT_LEN_1, X86_BREAKPOINT_WRITE,
743                                 addr, true);
744                 if (IS_ERR(bp))
745                         err = PTR_ERR(bp);
746                 else
747                         t->ptrace_bps[nr] = bp;
748         } else {
749                 struct perf_event_attr attr = bp->attr;
750 
751                 attr.bp_addr = addr;
752                 err = modify_user_hw_breakpoint(bp, &attr);
753         }
754 
755         return err;
756 }
757 
758 /*
759  * Handle PTRACE_POKEUSR calls for the debug register area.
760  */
761 static int ptrace_set_debugreg(struct task_struct *tsk, int n,
762                                unsigned long val)
763 {
764         struct thread_struct *thread = &tsk->thread;
765         /* There are no DR4 or DR5 registers */
766         int rc = -EIO;
767 
768         if (n < HBP_NUM) {
769                 rc = ptrace_set_breakpoint_addr(tsk, n, val);
770         } else if (n == 6) {
771                 thread->debugreg6 = val;
772                 rc = 0;
773         } else if (n == 7) {
774                 rc = ptrace_write_dr7(tsk, val);
775                 if (!rc)
776                         thread->ptrace_dr7 = val;
777         }
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 #ifdef CONFIG_X86_X32_ABI
1133 static long x32_arch_ptrace(struct task_struct *child,
1134                             compat_long_t request, compat_ulong_t caddr,
1135                             compat_ulong_t cdata)
1136 {
1137         unsigned long addr = caddr;
1138         unsigned long data = cdata;
1139         void __user *datap = compat_ptr(data);
1140         int ret;
1141 
1142         switch (request) {
1143         /* Read 32bits at location addr in the USER area.  Only allow
1144            to return the lower 32bits of segment and debug registers.  */
1145         case PTRACE_PEEKUSR: {
1146                 u32 tmp;
1147 
1148                 ret = -EIO;
1149                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1150                     addr < offsetof(struct user_regs_struct, cs))
1151                         break;
1152 
1153                 tmp = 0;  /* Default return condition */
1154                 if (addr < sizeof(struct user_regs_struct))
1155                         tmp = getreg(child, addr);
1156                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1157                          addr <= offsetof(struct user, u_debugreg[7])) {
1158                         addr -= offsetof(struct user, u_debugreg[0]);
1159                         tmp = ptrace_get_debugreg(child, addr / sizeof(data));
1160                 }
1161                 ret = put_user(tmp, (__u32 __user *)datap);
1162                 break;
1163         }
1164 
1165         /* Write the word at location addr in the USER area.  Only allow
1166            to update segment and debug registers with the upper 32bits
1167            zero-extended. */
1168         case PTRACE_POKEUSR:
1169                 ret = -EIO;
1170                 if ((addr & (sizeof(data) - 1)) || addr >= sizeof(struct user) ||
1171                     addr < offsetof(struct user_regs_struct, cs))
1172                         break;
1173 
1174                 if (addr < sizeof(struct user_regs_struct))
1175                         ret = putreg(child, addr, data);
1176                 else if (addr >= offsetof(struct user, u_debugreg[0]) &&
1177                          addr <= offsetof(struct user, u_debugreg[7])) {
1178                         addr -= offsetof(struct user, u_debugreg[0]);
1179                         ret = ptrace_set_debugreg(child,
1180                                                   addr / sizeof(data), data);
1181                 }
1182                 break;
1183 
1184         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1185                 return copy_regset_to_user(child,
1186                                            task_user_regset_view(current),
1187                                            REGSET_GENERAL,
1188                                            0, sizeof(struct user_regs_struct),
1189                                            datap);
1190 
1191         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1192                 return copy_regset_from_user(child,
1193                                              task_user_regset_view(current),
1194                                              REGSET_GENERAL,
1195                                              0, sizeof(struct user_regs_struct),
1196                                              datap);
1197 
1198         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1199                 return copy_regset_to_user(child,
1200                                            task_user_regset_view(current),
1201                                            REGSET_FP,
1202                                            0, sizeof(struct user_i387_struct),
1203                                            datap);
1204 
1205         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1206                 return copy_regset_from_user(child,
1207                                              task_user_regset_view(current),
1208                                              REGSET_FP,
1209                                              0, sizeof(struct user_i387_struct),
1210                                              datap);
1211 
1212         default:
1213                 return compat_ptrace_request(child, request, addr, data);
1214         }
1215 
1216         return ret;
1217 }
1218 #endif
1219 
1220 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
1221                         compat_ulong_t caddr, compat_ulong_t cdata)
1222 {
1223         unsigned long addr = caddr;
1224         unsigned long data = cdata;
1225         void __user *datap = compat_ptr(data);
1226         int ret;
1227         __u32 val;
1228 
1229 #ifdef CONFIG_X86_X32_ABI
1230         if (!is_ia32_task())
1231                 return x32_arch_ptrace(child, request, caddr, cdata);
1232 #endif
1233 
1234         switch (request) {
1235         case PTRACE_PEEKUSR:
1236                 ret = getreg32(child, addr, &val);
1237                 if (ret == 0)
1238                         ret = put_user(val, (__u32 __user *)datap);
1239                 break;
1240 
1241         case PTRACE_POKEUSR:
1242                 ret = putreg32(child, addr, data);
1243                 break;
1244 
1245         case PTRACE_GETREGS:    /* Get all gp regs from the child. */
1246                 return copy_regset_to_user(child, &user_x86_32_view,
1247                                            REGSET_GENERAL,
1248                                            0, sizeof(struct user_regs_struct32),
1249                                            datap);
1250 
1251         case PTRACE_SETREGS:    /* Set all gp regs in the child. */
1252                 return copy_regset_from_user(child, &user_x86_32_view,
1253                                              REGSET_GENERAL, 0,
1254                                              sizeof(struct user_regs_struct32),
1255                                              datap);
1256 
1257         case PTRACE_GETFPREGS:  /* Get the child FPU state. */
1258                 return copy_regset_to_user(child, &user_x86_32_view,
1259                                            REGSET_FP, 0,
1260                                            sizeof(struct user_i387_ia32_struct),
1261                                            datap);
1262 
1263         case PTRACE_SETFPREGS:  /* Set the child FPU state. */
1264                 return copy_regset_from_user(
1265                         child, &user_x86_32_view, REGSET_FP,
1266                         0, sizeof(struct user_i387_ia32_struct), datap);
1267 
1268         case PTRACE_GETFPXREGS: /* Get the child extended FPU state. */
1269                 return copy_regset_to_user(child, &user_x86_32_view,
1270                                            REGSET_XFP, 0,
1271                                            sizeof(struct user32_fxsr_struct),
1272                                            datap);
1273 
1274         case PTRACE_SETFPXREGS: /* Set the child extended FPU state. */
1275                 return copy_regset_from_user(child, &user_x86_32_view,
1276                                              REGSET_XFP, 0,
1277                                              sizeof(struct user32_fxsr_struct),
1278                                              datap);
1279 
1280         case PTRACE_GET_THREAD_AREA:
1281         case PTRACE_SET_THREAD_AREA:
1282                 return arch_ptrace(child, request, addr, data);
1283 
1284         default:
1285                 return compat_ptrace_request(child, request, addr, data);
1286         }
1287 
1288         return ret;
1289 }
1290 
1291 #endif  /* CONFIG_IA32_EMULATION */
1292 
1293 #ifdef CONFIG_X86_64
1294 
1295 static struct user_regset x86_64_regsets[] __read_mostly = {
1296         [REGSET_GENERAL] = {
1297                 .core_note_type = NT_PRSTATUS,
1298                 .n = sizeof(struct user_regs_struct) / sizeof(long),
1299                 .size = sizeof(long), .align = sizeof(long),
1300                 .get = genregs_get, .set = genregs_set
1301         },
1302         [REGSET_FP] = {
1303                 .core_note_type = NT_PRFPREG,
1304                 .n = sizeof(struct user_i387_struct) / sizeof(long),
1305                 .size = sizeof(long), .align = sizeof(long),
1306                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1307         },
1308         [REGSET_XSTATE] = {
1309                 .core_note_type = NT_X86_XSTATE,
1310                 .size = sizeof(u64), .align = sizeof(u64),
1311                 .active = xstateregs_active, .get = xstateregs_get,
1312                 .set = xstateregs_set
1313         },
1314         [REGSET_IOPERM64] = {
1315                 .core_note_type = NT_386_IOPERM,
1316                 .n = IO_BITMAP_LONGS,
1317                 .size = sizeof(long), .align = sizeof(long),
1318                 .active = ioperm_active, .get = ioperm_get
1319         },
1320 };
1321 
1322 static const struct user_regset_view user_x86_64_view = {
1323         .name = "x86_64", .e_machine = EM_X86_64,
1324         .regsets = x86_64_regsets, .n = ARRAY_SIZE(x86_64_regsets)
1325 };
1326 
1327 #else  /* CONFIG_X86_32 */
1328 
1329 #define user_regs_struct32      user_regs_struct
1330 #define genregs32_get           genregs_get
1331 #define genregs32_set           genregs_set
1332 
1333 #endif  /* CONFIG_X86_64 */
1334 
1335 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1336 static struct user_regset x86_32_regsets[] __read_mostly = {
1337         [REGSET_GENERAL] = {
1338                 .core_note_type = NT_PRSTATUS,
1339                 .n = sizeof(struct user_regs_struct32) / sizeof(u32),
1340                 .size = sizeof(u32), .align = sizeof(u32),
1341                 .get = genregs32_get, .set = genregs32_set
1342         },
1343         [REGSET_FP] = {
1344                 .core_note_type = NT_PRFPREG,
1345                 .n = sizeof(struct user_i387_ia32_struct) / sizeof(u32),
1346                 .size = sizeof(u32), .align = sizeof(u32),
1347                 .active = fpregs_active, .get = fpregs_get, .set = fpregs_set
1348         },
1349         [REGSET_XFP] = {
1350                 .core_note_type = NT_PRXFPREG,
1351                 .n = sizeof(struct user32_fxsr_struct) / sizeof(u32),
1352                 .size = sizeof(u32), .align = sizeof(u32),
1353                 .active = xfpregs_active, .get = xfpregs_get, .set = xfpregs_set
1354         },
1355         [REGSET_XSTATE] = {
1356                 .core_note_type = NT_X86_XSTATE,
1357                 .size = sizeof(u64), .align = sizeof(u64),
1358                 .active = xstateregs_active, .get = xstateregs_get,
1359                 .set = xstateregs_set
1360         },
1361         [REGSET_TLS] = {
1362                 .core_note_type = NT_386_TLS,
1363                 .n = GDT_ENTRY_TLS_ENTRIES, .bias = GDT_ENTRY_TLS_MIN,
1364                 .size = sizeof(struct user_desc),
1365                 .align = sizeof(struct user_desc),
1366                 .active = regset_tls_active,
1367                 .get = regset_tls_get, .set = regset_tls_set
1368         },
1369         [REGSET_IOPERM32] = {
1370                 .core_note_type = NT_386_IOPERM,
1371                 .n = IO_BITMAP_BYTES / sizeof(u32),
1372                 .size = sizeof(u32), .align = sizeof(u32),
1373                 .active = ioperm_active, .get = ioperm_get
1374         },
1375 };
1376 
1377 static const struct user_regset_view user_x86_32_view = {
1378         .name = "i386", .e_machine = EM_386,
1379         .regsets = x86_32_regsets, .n = ARRAY_SIZE(x86_32_regsets)
1380 };
1381 #endif
1382 
1383 /*
1384  * This represents bytes 464..511 in the memory layout exported through
1385  * the REGSET_XSTATE interface.
1386  */
1387 u64 xstate_fx_sw_bytes[USER_XSTATE_FX_SW_WORDS];
1388 
1389 void update_regset_xstate_info(unsigned int size, u64 xstate_mask)
1390 {
1391 #ifdef CONFIG_X86_64
1392         x86_64_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1393 #endif
1394 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1395         x86_32_regsets[REGSET_XSTATE].n = size / sizeof(u64);
1396 #endif
1397         xstate_fx_sw_bytes[USER_XSTATE_XCR0_WORD] = xstate_mask;
1398 }
1399 
1400 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
1401 {
1402 #ifdef CONFIG_IA32_EMULATION
1403         if (test_tsk_thread_flag(task, TIF_IA32))
1404 #endif
1405 #if defined CONFIG_X86_32 || defined CONFIG_IA32_EMULATION
1406                 return &user_x86_32_view;
1407 #endif
1408 #ifdef CONFIG_X86_64
1409         return &user_x86_64_view;
1410 #endif
1411 }
1412 
1413 static void fill_sigtrap_info(struct task_struct *tsk,
1414                                 struct pt_regs *regs,
1415                                 int error_code, int si_code,
1416                                 struct siginfo *info)
1417 {
1418         tsk->thread.trap_nr = X86_TRAP_DB;
1419         tsk->thread.error_code = error_code;
1420 
1421         memset(info, 0, sizeof(*info));
1422         info->si_signo = SIGTRAP;
1423         info->si_code = si_code;
1424         info->si_addr = user_mode_vm(regs) ? (void __user *)regs->ip : NULL;
1425 }
1426 
1427 void user_single_step_siginfo(struct task_struct *tsk,
1428                                 struct pt_regs *regs,
1429                                 struct siginfo *info)
1430 {
1431         fill_sigtrap_info(tsk, regs, 0, TRAP_BRKPT, info);
1432 }
1433 
1434 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs,
1435                                          int error_code, int si_code)
1436 {
1437         struct siginfo info;
1438 
1439         fill_sigtrap_info(tsk, regs, error_code, si_code, &info);
1440         /* Send us the fake SIGTRAP */
1441         force_sig_info(SIGTRAP, &info, tsk);
1442 }
1443 
1444 
1445 #ifdef CONFIG_X86_32
1446 # define IS_IA32        1
1447 #elif defined CONFIG_IA32_EMULATION
1448 # define IS_IA32        is_compat_task()
1449 #else
1450 # define IS_IA32        0
1451 #endif
1452 
1453 /*
1454  * We must return the syscall number to actually look up in the table.
1455  * This can be -1L to skip running any syscall at all.
1456  */
1457 long syscall_trace_enter(struct pt_regs *regs)
1458 {
1459         long ret = 0;
1460 
1461         user_exit();
1462 
1463         /*
1464          * If we stepped into a sysenter/syscall insn, it trapped in
1465          * kernel mode; do_debug() cleared TF and set TIF_SINGLESTEP.
1466          * If user-mode had set TF itself, then it's still clear from
1467          * do_debug() and we need to set it again to restore the user
1468          * state.  If we entered on the slow path, TF was already set.
1469          */
1470         if (test_thread_flag(TIF_SINGLESTEP))
1471                 regs->flags |= X86_EFLAGS_TF;
1472 
1473         /* do the secure computing check first */
1474         if (secure_computing(regs->orig_ax)) {
1475                 /* seccomp failures shouldn't expose any additional code. */
1476                 ret = -1L;
1477                 goto out;
1478         }
1479 
1480         if (unlikely(test_thread_flag(TIF_SYSCALL_EMU)))
1481                 ret = -1L;
1482 
1483         if ((ret || test_thread_flag(TIF_SYSCALL_TRACE)) &&
1484             tracehook_report_syscall_entry(regs))
1485                 ret = -1L;
1486 
1487         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1488                 trace_sys_enter(regs, regs->orig_ax);
1489 
1490         if (IS_IA32)
1491                 audit_syscall_entry(AUDIT_ARCH_I386,
1492                                     regs->orig_ax,
1493                                     regs->bx, regs->cx,
1494                                     regs->dx, regs->si);
1495 #ifdef CONFIG_X86_64
1496         else
1497                 audit_syscall_entry(AUDIT_ARCH_X86_64,
1498                                     regs->orig_ax,
1499                                     regs->di, regs->si,
1500                                     regs->dx, regs->r10);
1501 #endif
1502 
1503 out:
1504         return ret ?: regs->orig_ax;
1505 }
1506 
1507 void syscall_trace_leave(struct pt_regs *regs)
1508 {
1509         bool step;
1510 
1511         /*
1512          * We may come here right after calling schedule_user()
1513          * or do_notify_resume(), in which case we can be in RCU
1514          * user mode.
1515          */
1516         user_exit();
1517 
1518         audit_syscall_exit(regs);
1519 
1520         if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
1521                 trace_sys_exit(regs, regs->ax);
1522 
1523         /*
1524          * If TIF_SYSCALL_EMU is set, we only get here because of
1525          * TIF_SINGLESTEP (i.e. this is PTRACE_SYSEMU_SINGLESTEP).
1526          * We already reported this syscall instruction in
1527          * syscall_trace_enter().
1528          */
1529         step = unlikely(test_thread_flag(TIF_SINGLESTEP)) &&
1530                         !test_thread_flag(TIF_SYSCALL_EMU);
1531         if (step || test_thread_flag(TIF_SYSCALL_TRACE))
1532                 tracehook_report_syscall_exit(regs, step);
1533 
1534         user_enter();
1535 }
1536 

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