1 // SPDX-License-Identifier: GPL-2.0
3 * Kernel support for the ptrace() and syscall tracing interfaces.
5 * Copyright (C) 2000 Hewlett-Packard Co, Linuxcare Inc.
6 * Copyright (C) 2000 Matthew Wilcox <matthew@wil.cx>
7 * Copyright (C) 2000 David Huggins-Daines <dhd@debian.org>
8 * Copyright (C) 2008-2016 Helge Deller <deller@gmx.de>
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
14 #include <linux/smp.h>
15 #include <linux/elf.h>
16 #include <linux/errno.h>
17 #include <linux/ptrace.h>
18 #include <linux/tracehook.h>
19 #include <linux/user.h>
20 #include <linux/personality.h>
21 #include <linux/regset.h>
22 #include <linux/security.h>
23 #include <linux/seccomp.h>
24 #include <linux/compat.h>
25 #include <linux/signal.h>
26 #include <linux/audit.h>
28 #include <linux/uaccess.h>
29 #include <asm/pgtable.h>
30 #include <asm/processor.h>
31 #include <asm/asm-offsets.h>
33 /* PSW bits we allow the debugger to modify */
34 #define USER_PSW_BITS (PSW_N | PSW_B | PSW_V | PSW_CB)
36 #define CREATE_TRACE_POINTS
37 #include <trace/events/syscalls.h>
40 * These are our native regset flavors.
48 * Called by kernel/ptrace.c when detaching..
50 * Make sure single step bits etc are not set.
52 void ptrace_disable(struct task_struct *task)
54 clear_tsk_thread_flag(task, TIF_SINGLESTEP);
55 clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
57 /* make sure the trap bits are not set */
65 * The following functions are called by ptrace_resume() when
66 * enabling or disabling single/block tracing.
68 void user_disable_single_step(struct task_struct *task)
73 void user_enable_single_step(struct task_struct *task)
75 clear_tsk_thread_flag(task, TIF_BLOCKSTEP);
76 set_tsk_thread_flag(task, TIF_SINGLESTEP);
78 if (pa_psw(task)->n) {
79 /* Nullified, just crank over the queue. */
80 task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
81 task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
82 task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
89 /* Don't wake up the task, but let the
90 parent know something happened. */
91 force_sig_fault(SIGTRAP, TRAP_TRACE,
92 (void __user *) (task_regs(task)->iaoq[0] & ~3),
94 /* notify_parent(task, SIGCHLD); */
98 /* Enable recovery counter traps. The recovery counter
99 * itself will be set to zero on a task switch. If the
100 * task is suspended on a syscall then the syscall return
101 * path will overwrite the recovery counter with a suitable
102 * value such that it traps once back in user space. We
103 * disable interrupts in the tasks PSW here also, to avoid
104 * interrupts while the recovery counter is decrementing.
112 void user_enable_block_step(struct task_struct *task)
114 clear_tsk_thread_flag(task, TIF_SINGLESTEP);
115 set_tsk_thread_flag(task, TIF_BLOCKSTEP);
117 /* Enable taken branch trap. */
124 long arch_ptrace(struct task_struct *child, long request,
125 unsigned long addr, unsigned long data)
127 unsigned long __user *datap = (unsigned long __user *)data;
133 /* Read the word at location addr in the USER area. For ptraced
134 processes, the kernel saves all regs on a syscall. */
136 if ((addr & (sizeof(unsigned long)-1)) ||
137 addr >= sizeof(struct pt_regs))
139 tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
140 ret = put_user(tmp, datap);
143 /* Write the word at location addr in the USER area. This will need
144 to change when the kernel no longer saves all regs on a syscall.
145 FIXME. There is a problem at the moment in that r3-r18 are only
146 saved if the process is ptraced on syscall entry, and even then
147 those values are overwritten by actual register values on syscall
150 /* Some register values written here may be ignored in
151 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
152 * r31/r31+4, and not with the values in pt_regs.
154 if (addr == PT_PSW) {
155 /* Allow writing to Nullify, Divide-step-correction,
156 * and carry/borrow bits.
157 * BEWARE, if you set N, and then single step, it won't
158 * stop on the nullified instruction.
160 data &= USER_PSW_BITS;
161 task_regs(child)->gr[0] &= ~USER_PSW_BITS;
162 task_regs(child)->gr[0] |= data;
167 if ((addr & (sizeof(unsigned long)-1)) ||
168 addr >= sizeof(struct pt_regs))
170 if ((addr >= PT_GR1 && addr <= PT_GR31) ||
171 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
172 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
174 *(unsigned long *) ((char *) task_regs(child) + addr) = data;
179 case PTRACE_GETREGS: /* Get all gp regs from the child. */
180 return copy_regset_to_user(child,
181 task_user_regset_view(current),
183 0, sizeof(struct user_regs_struct),
186 case PTRACE_SETREGS: /* Set all gp regs in the child. */
187 return copy_regset_from_user(child,
188 task_user_regset_view(current),
190 0, sizeof(struct user_regs_struct),
193 case PTRACE_GETFPREGS: /* Get the child FPU state. */
194 return copy_regset_to_user(child,
195 task_user_regset_view(current),
197 0, sizeof(struct user_fp_struct),
200 case PTRACE_SETFPREGS: /* Set the child FPU state. */
201 return copy_regset_from_user(child,
202 task_user_regset_view(current),
204 0, sizeof(struct user_fp_struct),
208 ret = ptrace_request(child, request, addr, data);
218 /* This function is needed to translate 32 bit pt_regs offsets in to
219 * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel
220 * will request offset 12 if it wants gr3, but the lower 32 bits of
221 * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
222 * This code relies on a 32 bit pt_regs being comprised of 32 bit values
223 * except for the fp registers which (a) are 64 bits, and (b) follow
224 * the gr registers at the start of pt_regs. The 32 bit pt_regs should
225 * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
226 * being 64 bit in both cases.
229 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
232 return sizeof(struct pt_regs);
233 else if (offset <= 32*4) /* gr[0..31] */
234 return offset * 2 + 4;
235 else if (offset <= 32*4+32*8) /* gr[0..31] + fr[0..31] */
236 return offset + 32*4;
237 else if (offset < sizeof(struct pt_regs)/2 + 32*4)
238 return offset * 2 + 4 - 32*8;
240 return sizeof(struct pt_regs);
243 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
244 compat_ulong_t addr, compat_ulong_t data)
252 if (addr & (sizeof(compat_uint_t)-1))
254 addr = translate_usr_offset(addr);
255 if (addr >= sizeof(struct pt_regs))
258 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
259 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
262 /* Write the word at location addr in the USER area. This will need
263 to change when the kernel no longer saves all regs on a syscall.
264 FIXME. There is a problem at the moment in that r3-r18 are only
265 saved if the process is ptraced on syscall entry, and even then
266 those values are overwritten by actual register values on syscall
269 /* Some register values written here may be ignored in
270 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
271 * r31/r31+4, and not with the values in pt_regs.
273 if (addr == PT_PSW) {
274 /* Since PT_PSW==0, it is valid for 32 bit processes
275 * under 64 bit kernels as well.
277 ret = arch_ptrace(child, request, addr, data);
279 if (addr & (sizeof(compat_uint_t)-1))
281 addr = translate_usr_offset(addr);
282 if (addr >= sizeof(struct pt_regs))
284 if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
285 /* Special case, fp regs are 64 bits anyway */
286 *(__u64 *) ((char *) task_regs(child) + addr) = data;
289 else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
290 addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
292 /* Zero the top 32 bits */
293 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
294 *(__u32 *) ((char *) task_regs(child) + addr) = data;
301 ret = compat_ptrace_request(child, request, addr, data);
309 long do_syscall_trace_enter(struct pt_regs *regs)
311 if (test_thread_flag(TIF_SYSCALL_TRACE) &&
312 tracehook_report_syscall_entry(regs)) {
314 * Tracing decided this syscall should not happen or the
315 * debugger stored an invalid system call number. Skip
316 * the system call and the system call restart handling.
322 /* Do the secure computing check after ptrace. */
323 if (secure_computing(NULL) == -1)
326 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
327 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
328 trace_sys_enter(regs, regs->gr[20]);
332 if (!is_compat_task())
333 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
334 regs->gr[24], regs->gr[23]);
337 audit_syscall_entry(regs->gr[20] & 0xffffffff,
338 regs->gr[26] & 0xffffffff,
339 regs->gr[25] & 0xffffffff,
340 regs->gr[24] & 0xffffffff,
341 regs->gr[23] & 0xffffffff);
345 * Sign extend the syscall number to 64bit since it may have been
346 * modified by a compat ptrace call
348 return (int) ((u32) regs->gr[20]);
351 void do_syscall_trace_exit(struct pt_regs *regs)
353 int stepping = test_thread_flag(TIF_SINGLESTEP) ||
354 test_thread_flag(TIF_BLOCKSTEP);
356 audit_syscall_exit(regs);
358 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
359 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
360 trace_sys_exit(regs, regs->gr[20]);
363 if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
364 tracehook_report_syscall_exit(regs, stepping);
372 static int fpr_get(struct task_struct *target,
373 const struct user_regset *regset,
374 unsigned int pos, unsigned int count,
375 void *kbuf, void __user *ubuf)
377 struct pt_regs *regs = task_regs(target);
379 __u64 __user *u = ubuf;
383 count /= sizeof(reg);
386 for (; count > 0 && pos < ELF_NFPREG; --count)
387 *k++ = regs->fr[pos++];
389 for (; count > 0 && pos < ELF_NFPREG; --count)
390 if (__put_user(regs->fr[pos++], u++))
396 count *= sizeof(reg);
397 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
398 ELF_NFPREG * sizeof(reg), -1);
401 static int fpr_set(struct task_struct *target,
402 const struct user_regset *regset,
403 unsigned int pos, unsigned int count,
404 const void *kbuf, const void __user *ubuf)
406 struct pt_regs *regs = task_regs(target);
407 const __u64 *k = kbuf;
408 const __u64 __user *u = ubuf;
412 count /= sizeof(reg);
415 for (; count > 0 && pos < ELF_NFPREG; --count)
416 regs->fr[pos++] = *k++;
418 for (; count > 0 && pos < ELF_NFPREG; --count) {
419 if (__get_user(reg, u++))
421 regs->fr[pos++] = reg;
427 count *= sizeof(reg);
428 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
429 ELF_NFPREG * sizeof(reg), -1);
432 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
434 static unsigned long get_reg(struct pt_regs *regs, int num)
437 case RI(gr[0]) ... RI(gr[31]): return regs->gr[num - RI(gr[0])];
438 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
439 case RI(iasq[0]): return regs->iasq[0];
440 case RI(iasq[1]): return regs->iasq[1];
441 case RI(iaoq[0]): return regs->iaoq[0];
442 case RI(iaoq[1]): return regs->iaoq[1];
443 case RI(sar): return regs->sar;
444 case RI(iir): return regs->iir;
445 case RI(isr): return regs->isr;
446 case RI(ior): return regs->ior;
447 case RI(ipsw): return regs->ipsw;
448 case RI(cr27): return regs->cr27;
449 case RI(cr0): return mfctl(0);
450 case RI(cr24): return mfctl(24);
451 case RI(cr25): return mfctl(25);
452 case RI(cr26): return mfctl(26);
453 case RI(cr28): return mfctl(28);
454 case RI(cr29): return mfctl(29);
455 case RI(cr30): return mfctl(30);
456 case RI(cr31): return mfctl(31);
457 case RI(cr8): return mfctl(8);
458 case RI(cr9): return mfctl(9);
459 case RI(cr12): return mfctl(12);
460 case RI(cr13): return mfctl(13);
461 case RI(cr10): return mfctl(10);
462 case RI(cr15): return mfctl(15);
467 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
472 * Allow writing to Nullify, Divide-step-correction,
473 * and carry/borrow bits.
474 * BEWARE, if you set N, and then single step, it won't
475 * stop on the nullified instruction.
477 val &= USER_PSW_BITS;
478 regs->gr[0] &= ~USER_PSW_BITS;
481 case RI(gr[1]) ... RI(gr[31]):
482 regs->gr[num - RI(gr[0])] = val;
486 regs->iaoq[num - RI(iaoq[0])] = val;
488 case RI(sar): regs->sar = val;
492 /* do not allow to change any of the following registers (yet) */
493 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
494 case RI(iasq[0]): return regs->iasq[0];
495 case RI(iasq[1]): return regs->iasq[1];
496 case RI(iir): return regs->iir;
497 case RI(isr): return regs->isr;
498 case RI(ior): return regs->ior;
499 case RI(ipsw): return regs->ipsw;
500 case RI(cr27): return regs->cr27;
501 case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
502 case cr8, cr9, cr12, cr13, cr10, cr15;
507 static int gpr_get(struct task_struct *target,
508 const struct user_regset *regset,
509 unsigned int pos, unsigned int count,
510 void *kbuf, void __user *ubuf)
512 struct pt_regs *regs = task_regs(target);
513 unsigned long *k = kbuf;
514 unsigned long __user *u = ubuf;
518 count /= sizeof(reg);
521 for (; count > 0 && pos < ELF_NGREG; --count)
522 *k++ = get_reg(regs, pos++);
524 for (; count > 0 && pos < ELF_NGREG; --count)
525 if (__put_user(get_reg(regs, pos++), u++))
530 count *= sizeof(reg);
531 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
532 ELF_NGREG * sizeof(reg), -1);
535 static int gpr_set(struct task_struct *target,
536 const struct user_regset *regset,
537 unsigned int pos, unsigned int count,
538 const void *kbuf, const void __user *ubuf)
540 struct pt_regs *regs = task_regs(target);
541 const unsigned long *k = kbuf;
542 const unsigned long __user *u = ubuf;
546 count /= sizeof(reg);
549 for (; count > 0 && pos < ELF_NGREG; --count)
550 set_reg(regs, pos++, *k++);
552 for (; count > 0 && pos < ELF_NGREG; --count) {
553 if (__get_user(reg, u++))
555 set_reg(regs, pos++, reg);
561 count *= sizeof(reg);
562 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
563 ELF_NGREG * sizeof(reg), -1);
566 static const struct user_regset native_regsets[] = {
568 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
569 .size = sizeof(long), .align = sizeof(long),
570 .get = gpr_get, .set = gpr_set
573 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
574 .size = sizeof(__u64), .align = sizeof(__u64),
575 .get = fpr_get, .set = fpr_set
579 static const struct user_regset_view user_parisc_native_view = {
580 .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
581 .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
585 #include <linux/compat.h>
587 static int gpr32_get(struct task_struct *target,
588 const struct user_regset *regset,
589 unsigned int pos, unsigned int count,
590 void *kbuf, void __user *ubuf)
592 struct pt_regs *regs = task_regs(target);
593 compat_ulong_t *k = kbuf;
594 compat_ulong_t __user *u = ubuf;
598 count /= sizeof(reg);
601 for (; count > 0 && pos < ELF_NGREG; --count)
602 *k++ = get_reg(regs, pos++);
604 for (; count > 0 && pos < ELF_NGREG; --count)
605 if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
611 count *= sizeof(reg);
612 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
613 ELF_NGREG * sizeof(reg), -1);
616 static int gpr32_set(struct task_struct *target,
617 const struct user_regset *regset,
618 unsigned int pos, unsigned int count,
619 const void *kbuf, const void __user *ubuf)
621 struct pt_regs *regs = task_regs(target);
622 const compat_ulong_t *k = kbuf;
623 const compat_ulong_t __user *u = ubuf;
627 count /= sizeof(reg);
630 for (; count > 0 && pos < ELF_NGREG; --count)
631 set_reg(regs, pos++, *k++);
633 for (; count > 0 && pos < ELF_NGREG; --count) {
634 if (__get_user(reg, u++))
636 set_reg(regs, pos++, reg);
642 count *= sizeof(reg);
643 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
644 ELF_NGREG * sizeof(reg), -1);
648 * These are the regset flavors matching the 32bit native set.
650 static const struct user_regset compat_regsets[] = {
652 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
653 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
654 .get = gpr32_get, .set = gpr32_set
657 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
658 .size = sizeof(__u64), .align = sizeof(__u64),
659 .get = fpr_get, .set = fpr_set
663 static const struct user_regset_view user_parisc_compat_view = {
664 .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
665 .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
667 #endif /* CONFIG_64BIT */
669 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
671 BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
672 BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
674 if (is_compat_task())
675 return &user_parisc_compat_view;
677 return &user_parisc_native_view;
681 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
683 struct pt_regs_offset {
688 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
689 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
690 #define REG_OFFSET_END {.name = NULL, .offset = 0}
692 static const struct pt_regs_offset regoffset_table[] = {
693 REG_OFFSET_INDEX(gr,0),
694 REG_OFFSET_INDEX(gr,1),
695 REG_OFFSET_INDEX(gr,2),
696 REG_OFFSET_INDEX(gr,3),
697 REG_OFFSET_INDEX(gr,4),
698 REG_OFFSET_INDEX(gr,5),
699 REG_OFFSET_INDEX(gr,6),
700 REG_OFFSET_INDEX(gr,7),
701 REG_OFFSET_INDEX(gr,8),
702 REG_OFFSET_INDEX(gr,9),
703 REG_OFFSET_INDEX(gr,10),
704 REG_OFFSET_INDEX(gr,11),
705 REG_OFFSET_INDEX(gr,12),
706 REG_OFFSET_INDEX(gr,13),
707 REG_OFFSET_INDEX(gr,14),
708 REG_OFFSET_INDEX(gr,15),
709 REG_OFFSET_INDEX(gr,16),
710 REG_OFFSET_INDEX(gr,17),
711 REG_OFFSET_INDEX(gr,18),
712 REG_OFFSET_INDEX(gr,19),
713 REG_OFFSET_INDEX(gr,20),
714 REG_OFFSET_INDEX(gr,21),
715 REG_OFFSET_INDEX(gr,22),
716 REG_OFFSET_INDEX(gr,23),
717 REG_OFFSET_INDEX(gr,24),
718 REG_OFFSET_INDEX(gr,25),
719 REG_OFFSET_INDEX(gr,26),
720 REG_OFFSET_INDEX(gr,27),
721 REG_OFFSET_INDEX(gr,28),
722 REG_OFFSET_INDEX(gr,29),
723 REG_OFFSET_INDEX(gr,30),
724 REG_OFFSET_INDEX(gr,31),
725 REG_OFFSET_INDEX(sr,0),
726 REG_OFFSET_INDEX(sr,1),
727 REG_OFFSET_INDEX(sr,2),
728 REG_OFFSET_INDEX(sr,3),
729 REG_OFFSET_INDEX(sr,4),
730 REG_OFFSET_INDEX(sr,5),
731 REG_OFFSET_INDEX(sr,6),
732 REG_OFFSET_INDEX(sr,7),
733 REG_OFFSET_INDEX(iasq,0),
734 REG_OFFSET_INDEX(iasq,1),
735 REG_OFFSET_INDEX(iaoq,0),
736 REG_OFFSET_INDEX(iaoq,1),
737 REG_OFFSET_NAME(cr27),
738 REG_OFFSET_NAME(ksp),
739 REG_OFFSET_NAME(kpc),
740 REG_OFFSET_NAME(sar),
741 REG_OFFSET_NAME(iir),
742 REG_OFFSET_NAME(isr),
743 REG_OFFSET_NAME(ior),
744 REG_OFFSET_NAME(ipsw),
749 * regs_query_register_offset() - query register offset from its name
750 * @name: the name of a register
752 * regs_query_register_offset() returns the offset of a register in struct
753 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
755 int regs_query_register_offset(const char *name)
757 const struct pt_regs_offset *roff;
758 for (roff = regoffset_table; roff->name != NULL; roff++)
759 if (!strcmp(roff->name, name))
765 * regs_query_register_name() - query register name from its offset
766 * @offset: the offset of a register in struct pt_regs.
768 * regs_query_register_name() returns the name of a register from its
769 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
771 const char *regs_query_register_name(unsigned int offset)
773 const struct pt_regs_offset *roff;
774 for (roff = regoffset_table; roff->name != NULL; roff++)
775 if (roff->offset == offset)