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 int rc = tracehook_report_syscall_entry(regs);
315 * As tracesys_next does not set %r28 to -ENOSYS
316 * when %r20 is set to -1, initialize it here.
318 regs->gr[28] = -ENOSYS;
322 * A nonzero return code from
323 * tracehook_report_syscall_entry() tells us
324 * to prevent the syscall execution. Skip
325 * the syscall call and the syscall restart handling.
327 * Note that the tracer may also just change
328 * regs->gr[20] to an invalid syscall number,
329 * that is handled by tracesys_next.
336 /* Do the secure computing check after ptrace. */
337 if (secure_computing(NULL) == -1)
340 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
341 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
342 trace_sys_enter(regs, regs->gr[20]);
346 if (!is_compat_task())
347 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
348 regs->gr[24], regs->gr[23]);
351 audit_syscall_entry(regs->gr[20] & 0xffffffff,
352 regs->gr[26] & 0xffffffff,
353 regs->gr[25] & 0xffffffff,
354 regs->gr[24] & 0xffffffff,
355 regs->gr[23] & 0xffffffff);
358 * Sign extend the syscall number to 64bit since it may have been
359 * modified by a compat ptrace call
361 return (int) ((u32) regs->gr[20]);
364 void do_syscall_trace_exit(struct pt_regs *regs)
366 int stepping = test_thread_flag(TIF_SINGLESTEP) ||
367 test_thread_flag(TIF_BLOCKSTEP);
369 audit_syscall_exit(regs);
371 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
372 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
373 trace_sys_exit(regs, regs->gr[20]);
376 if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
377 tracehook_report_syscall_exit(regs, stepping);
385 static int fpr_get(struct task_struct *target,
386 const struct user_regset *regset,
387 unsigned int pos, unsigned int count,
388 void *kbuf, void __user *ubuf)
390 struct pt_regs *regs = task_regs(target);
392 __u64 __user *u = ubuf;
396 count /= sizeof(reg);
399 for (; count > 0 && pos < ELF_NFPREG; --count)
400 *k++ = regs->fr[pos++];
402 for (; count > 0 && pos < ELF_NFPREG; --count)
403 if (__put_user(regs->fr[pos++], u++))
409 count *= sizeof(reg);
410 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
411 ELF_NFPREG * sizeof(reg), -1);
414 static int fpr_set(struct task_struct *target,
415 const struct user_regset *regset,
416 unsigned int pos, unsigned int count,
417 const void *kbuf, const void __user *ubuf)
419 struct pt_regs *regs = task_regs(target);
420 const __u64 *k = kbuf;
421 const __u64 __user *u = ubuf;
425 count /= sizeof(reg);
428 for (; count > 0 && pos < ELF_NFPREG; --count)
429 regs->fr[pos++] = *k++;
431 for (; count > 0 && pos < ELF_NFPREG; --count) {
432 if (__get_user(reg, u++))
434 regs->fr[pos++] = reg;
440 count *= sizeof(reg);
441 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
442 ELF_NFPREG * sizeof(reg), -1);
445 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
447 static unsigned long get_reg(struct pt_regs *regs, int num)
450 case RI(gr[0]) ... RI(gr[31]): return regs->gr[num - RI(gr[0])];
451 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
452 case RI(iasq[0]): return regs->iasq[0];
453 case RI(iasq[1]): return regs->iasq[1];
454 case RI(iaoq[0]): return regs->iaoq[0];
455 case RI(iaoq[1]): return regs->iaoq[1];
456 case RI(sar): return regs->sar;
457 case RI(iir): return regs->iir;
458 case RI(isr): return regs->isr;
459 case RI(ior): return regs->ior;
460 case RI(ipsw): return regs->ipsw;
461 case RI(cr27): return regs->cr27;
462 case RI(cr0): return mfctl(0);
463 case RI(cr24): return mfctl(24);
464 case RI(cr25): return mfctl(25);
465 case RI(cr26): return mfctl(26);
466 case RI(cr28): return mfctl(28);
467 case RI(cr29): return mfctl(29);
468 case RI(cr30): return mfctl(30);
469 case RI(cr31): return mfctl(31);
470 case RI(cr8): return mfctl(8);
471 case RI(cr9): return mfctl(9);
472 case RI(cr12): return mfctl(12);
473 case RI(cr13): return mfctl(13);
474 case RI(cr10): return mfctl(10);
475 case RI(cr15): return mfctl(15);
480 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
485 * Allow writing to Nullify, Divide-step-correction,
486 * and carry/borrow bits.
487 * BEWARE, if you set N, and then single step, it won't
488 * stop on the nullified instruction.
490 val &= USER_PSW_BITS;
491 regs->gr[0] &= ~USER_PSW_BITS;
494 case RI(gr[1]) ... RI(gr[31]):
495 regs->gr[num - RI(gr[0])] = val;
499 regs->iaoq[num - RI(iaoq[0])] = val;
501 case RI(sar): regs->sar = val;
505 /* do not allow to change any of the following registers (yet) */
506 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
507 case RI(iasq[0]): return regs->iasq[0];
508 case RI(iasq[1]): return regs->iasq[1];
509 case RI(iir): return regs->iir;
510 case RI(isr): return regs->isr;
511 case RI(ior): return regs->ior;
512 case RI(ipsw): return regs->ipsw;
513 case RI(cr27): return regs->cr27;
514 case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
515 case cr8, cr9, cr12, cr13, cr10, cr15;
520 static int gpr_get(struct task_struct *target,
521 const struct user_regset *regset,
522 unsigned int pos, unsigned int count,
523 void *kbuf, void __user *ubuf)
525 struct pt_regs *regs = task_regs(target);
526 unsigned long *k = kbuf;
527 unsigned long __user *u = ubuf;
531 count /= sizeof(reg);
534 for (; count > 0 && pos < ELF_NGREG; --count)
535 *k++ = get_reg(regs, pos++);
537 for (; count > 0 && pos < ELF_NGREG; --count)
538 if (__put_user(get_reg(regs, pos++), u++))
543 count *= sizeof(reg);
544 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
545 ELF_NGREG * sizeof(reg), -1);
548 static int gpr_set(struct task_struct *target,
549 const struct user_regset *regset,
550 unsigned int pos, unsigned int count,
551 const void *kbuf, const void __user *ubuf)
553 struct pt_regs *regs = task_regs(target);
554 const unsigned long *k = kbuf;
555 const unsigned long __user *u = ubuf;
559 count /= sizeof(reg);
562 for (; count > 0 && pos < ELF_NGREG; --count)
563 set_reg(regs, pos++, *k++);
565 for (; count > 0 && pos < ELF_NGREG; --count) {
566 if (__get_user(reg, u++))
568 set_reg(regs, pos++, reg);
574 count *= sizeof(reg);
575 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
576 ELF_NGREG * sizeof(reg), -1);
579 static const struct user_regset native_regsets[] = {
581 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
582 .size = sizeof(long), .align = sizeof(long),
583 .get = gpr_get, .set = gpr_set
586 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
587 .size = sizeof(__u64), .align = sizeof(__u64),
588 .get = fpr_get, .set = fpr_set
592 static const struct user_regset_view user_parisc_native_view = {
593 .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
594 .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
598 #include <linux/compat.h>
600 static int gpr32_get(struct task_struct *target,
601 const struct user_regset *regset,
602 unsigned int pos, unsigned int count,
603 void *kbuf, void __user *ubuf)
605 struct pt_regs *regs = task_regs(target);
606 compat_ulong_t *k = kbuf;
607 compat_ulong_t __user *u = ubuf;
611 count /= sizeof(reg);
614 for (; count > 0 && pos < ELF_NGREG; --count)
615 *k++ = get_reg(regs, pos++);
617 for (; count > 0 && pos < ELF_NGREG; --count)
618 if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
624 count *= sizeof(reg);
625 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
626 ELF_NGREG * sizeof(reg), -1);
629 static int gpr32_set(struct task_struct *target,
630 const struct user_regset *regset,
631 unsigned int pos, unsigned int count,
632 const void *kbuf, const void __user *ubuf)
634 struct pt_regs *regs = task_regs(target);
635 const compat_ulong_t *k = kbuf;
636 const compat_ulong_t __user *u = ubuf;
640 count /= sizeof(reg);
643 for (; count > 0 && pos < ELF_NGREG; --count)
644 set_reg(regs, pos++, *k++);
646 for (; count > 0 && pos < ELF_NGREG; --count) {
647 if (__get_user(reg, u++))
649 set_reg(regs, pos++, reg);
655 count *= sizeof(reg);
656 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
657 ELF_NGREG * sizeof(reg), -1);
661 * These are the regset flavors matching the 32bit native set.
663 static const struct user_regset compat_regsets[] = {
665 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
666 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
667 .get = gpr32_get, .set = gpr32_set
670 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
671 .size = sizeof(__u64), .align = sizeof(__u64),
672 .get = fpr_get, .set = fpr_set
676 static const struct user_regset_view user_parisc_compat_view = {
677 .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
678 .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
680 #endif /* CONFIG_64BIT */
682 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
684 BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
685 BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
687 if (is_compat_task())
688 return &user_parisc_compat_view;
690 return &user_parisc_native_view;
694 /* HAVE_REGS_AND_STACK_ACCESS_API feature */
696 struct pt_regs_offset {
701 #define REG_OFFSET_NAME(r) {.name = #r, .offset = offsetof(struct pt_regs, r)}
702 #define REG_OFFSET_INDEX(r,i) {.name = #r#i, .offset = offsetof(struct pt_regs, r[i])}
703 #define REG_OFFSET_END {.name = NULL, .offset = 0}
705 static const struct pt_regs_offset regoffset_table[] = {
706 REG_OFFSET_INDEX(gr,0),
707 REG_OFFSET_INDEX(gr,1),
708 REG_OFFSET_INDEX(gr,2),
709 REG_OFFSET_INDEX(gr,3),
710 REG_OFFSET_INDEX(gr,4),
711 REG_OFFSET_INDEX(gr,5),
712 REG_OFFSET_INDEX(gr,6),
713 REG_OFFSET_INDEX(gr,7),
714 REG_OFFSET_INDEX(gr,8),
715 REG_OFFSET_INDEX(gr,9),
716 REG_OFFSET_INDEX(gr,10),
717 REG_OFFSET_INDEX(gr,11),
718 REG_OFFSET_INDEX(gr,12),
719 REG_OFFSET_INDEX(gr,13),
720 REG_OFFSET_INDEX(gr,14),
721 REG_OFFSET_INDEX(gr,15),
722 REG_OFFSET_INDEX(gr,16),
723 REG_OFFSET_INDEX(gr,17),
724 REG_OFFSET_INDEX(gr,18),
725 REG_OFFSET_INDEX(gr,19),
726 REG_OFFSET_INDEX(gr,20),
727 REG_OFFSET_INDEX(gr,21),
728 REG_OFFSET_INDEX(gr,22),
729 REG_OFFSET_INDEX(gr,23),
730 REG_OFFSET_INDEX(gr,24),
731 REG_OFFSET_INDEX(gr,25),
732 REG_OFFSET_INDEX(gr,26),
733 REG_OFFSET_INDEX(gr,27),
734 REG_OFFSET_INDEX(gr,28),
735 REG_OFFSET_INDEX(gr,29),
736 REG_OFFSET_INDEX(gr,30),
737 REG_OFFSET_INDEX(gr,31),
738 REG_OFFSET_INDEX(sr,0),
739 REG_OFFSET_INDEX(sr,1),
740 REG_OFFSET_INDEX(sr,2),
741 REG_OFFSET_INDEX(sr,3),
742 REG_OFFSET_INDEX(sr,4),
743 REG_OFFSET_INDEX(sr,5),
744 REG_OFFSET_INDEX(sr,6),
745 REG_OFFSET_INDEX(sr,7),
746 REG_OFFSET_INDEX(iasq,0),
747 REG_OFFSET_INDEX(iasq,1),
748 REG_OFFSET_INDEX(iaoq,0),
749 REG_OFFSET_INDEX(iaoq,1),
750 REG_OFFSET_NAME(cr27),
751 REG_OFFSET_NAME(ksp),
752 REG_OFFSET_NAME(kpc),
753 REG_OFFSET_NAME(sar),
754 REG_OFFSET_NAME(iir),
755 REG_OFFSET_NAME(isr),
756 REG_OFFSET_NAME(ior),
757 REG_OFFSET_NAME(ipsw),
762 * regs_query_register_offset() - query register offset from its name
763 * @name: the name of a register
765 * regs_query_register_offset() returns the offset of a register in struct
766 * pt_regs from its name. If the name is invalid, this returns -EINVAL;
768 int regs_query_register_offset(const char *name)
770 const struct pt_regs_offset *roff;
771 for (roff = regoffset_table; roff->name != NULL; roff++)
772 if (!strcmp(roff->name, name))
778 * regs_query_register_name() - query register name from its offset
779 * @offset: the offset of a register in struct pt_regs.
781 * regs_query_register_name() returns the name of a register from its
782 * offset in struct pt_regs. If the @offset is invalid, this returns NULL;
784 const char *regs_query_register_name(unsigned int offset)
786 const struct pt_regs_offset *roff;
787 for (roff = regoffset_table; roff->name != NULL; roff++)
788 if (roff->offset == offset)