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) {
81 /* Nullified, just crank over the queue. */
82 task_regs(task)->iaoq[0] = task_regs(task)->iaoq[1];
83 task_regs(task)->iasq[0] = task_regs(task)->iasq[1];
84 task_regs(task)->iaoq[1] = task_regs(task)->iaoq[0] + 4;
91 /* Don't wake up the task, but let the
92 parent know something happened. */
93 si.si_code = TRAP_TRACE;
94 si.si_addr = (void __user *) (task_regs(task)->iaoq[0] & ~3);
95 si.si_signo = SIGTRAP;
97 force_sig_info(SIGTRAP, &si, task);
98 /* notify_parent(task, SIGCHLD); */
102 /* Enable recovery counter traps. The recovery counter
103 * itself will be set to zero on a task switch. If the
104 * task is suspended on a syscall then the syscall return
105 * path will overwrite the recovery counter with a suitable
106 * value such that it traps once back in user space. We
107 * disable interrupts in the tasks PSW here also, to avoid
108 * interrupts while the recovery counter is decrementing.
116 void user_enable_block_step(struct task_struct *task)
118 clear_tsk_thread_flag(task, TIF_SINGLESTEP);
119 set_tsk_thread_flag(task, TIF_BLOCKSTEP);
121 /* Enable taken branch trap. */
128 long arch_ptrace(struct task_struct *child, long request,
129 unsigned long addr, unsigned long data)
131 unsigned long __user *datap = (unsigned long __user *)data;
137 /* Read the word at location addr in the USER area. For ptraced
138 processes, the kernel saves all regs on a syscall. */
140 if ((addr & (sizeof(unsigned long)-1)) ||
141 addr >= sizeof(struct pt_regs))
143 tmp = *(unsigned long *) ((char *) task_regs(child) + addr);
144 ret = put_user(tmp, datap);
147 /* Write the word at location addr in the USER area. This will need
148 to change when the kernel no longer saves all regs on a syscall.
149 FIXME. There is a problem at the moment in that r3-r18 are only
150 saved if the process is ptraced on syscall entry, and even then
151 those values are overwritten by actual register values on syscall
154 /* Some register values written here may be ignored in
155 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
156 * r31/r31+4, and not with the values in pt_regs.
158 if (addr == PT_PSW) {
159 /* Allow writing to Nullify, Divide-step-correction,
160 * and carry/borrow bits.
161 * BEWARE, if you set N, and then single step, it won't
162 * stop on the nullified instruction.
164 data &= USER_PSW_BITS;
165 task_regs(child)->gr[0] &= ~USER_PSW_BITS;
166 task_regs(child)->gr[0] |= data;
171 if ((addr & (sizeof(unsigned long)-1)) ||
172 addr >= sizeof(struct pt_regs))
174 if (addr == PT_IAOQ0 || addr == PT_IAOQ1) {
175 data |= 3; /* ensure userspace privilege */
177 if ((addr >= PT_GR1 && addr <= PT_GR31) ||
178 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
179 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
181 *(unsigned long *) ((char *) task_regs(child) + addr) = data;
186 case PTRACE_GETREGS: /* Get all gp regs from the child. */
187 return copy_regset_to_user(child,
188 task_user_regset_view(current),
190 0, sizeof(struct user_regs_struct),
193 case PTRACE_SETREGS: /* Set all gp regs in the child. */
194 return copy_regset_from_user(child,
195 task_user_regset_view(current),
197 0, sizeof(struct user_regs_struct),
200 case PTRACE_GETFPREGS: /* Get the child FPU state. */
201 return copy_regset_to_user(child,
202 task_user_regset_view(current),
204 0, sizeof(struct user_fp_struct),
207 case PTRACE_SETFPREGS: /* Set the child FPU state. */
208 return copy_regset_from_user(child,
209 task_user_regset_view(current),
211 0, sizeof(struct user_fp_struct),
215 ret = ptrace_request(child, request, addr, data);
225 /* This function is needed to translate 32 bit pt_regs offsets in to
226 * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel
227 * will request offset 12 if it wants gr3, but the lower 32 bits of
228 * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
229 * This code relies on a 32 bit pt_regs being comprised of 32 bit values
230 * except for the fp registers which (a) are 64 bits, and (b) follow
231 * the gr registers at the start of pt_regs. The 32 bit pt_regs should
232 * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
233 * being 64 bit in both cases.
236 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
240 if (offset < 32*4) /* gr[0..31] */
241 pos = offset * 2 + 4;
242 else if (offset < 32*4+32*8) /* fr[0] ... fr[31] */
243 pos = (offset - 32*4) + PT_FR0;
244 else if (offset < sizeof(struct pt_regs)/2 + 32*4) /* sr[0] ... ipsw */
245 pos = (offset - 32*4 - 32*8) * 2 + PT_SR0 + 4;
247 pos = sizeof(struct pt_regs);
252 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
253 compat_ulong_t addr, compat_ulong_t data)
261 if (addr & (sizeof(compat_uint_t)-1))
263 addr = translate_usr_offset(addr);
264 if (addr >= sizeof(struct pt_regs))
267 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
268 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
271 /* Write the word at location addr in the USER area. This will need
272 to change when the kernel no longer saves all regs on a syscall.
273 FIXME. There is a problem at the moment in that r3-r18 are only
274 saved if the process is ptraced on syscall entry, and even then
275 those values are overwritten by actual register values on syscall
278 /* Some register values written here may be ignored in
279 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
280 * r31/r31+4, and not with the values in pt_regs.
282 if (addr == PT_PSW) {
283 /* Since PT_PSW==0, it is valid for 32 bit processes
284 * under 64 bit kernels as well.
286 ret = arch_ptrace(child, request, addr, data);
288 if (addr & (sizeof(compat_uint_t)-1))
290 addr = translate_usr_offset(addr);
291 if (addr >= sizeof(struct pt_regs))
293 if (addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4) {
294 data |= 3; /* ensure userspace privilege */
296 if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
297 /* Special case, fp regs are 64 bits anyway */
298 *(__u32 *) ((char *) task_regs(child) + addr) = data;
301 else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
302 addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
304 /* Zero the top 32 bits */
305 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
306 *(__u32 *) ((char *) task_regs(child) + addr) = data;
313 ret = compat_ptrace_request(child, request, addr, data);
321 long do_syscall_trace_enter(struct pt_regs *regs)
323 if (test_thread_flag(TIF_SYSCALL_TRACE)) {
324 int rc = tracehook_report_syscall_entry(regs);
327 * As tracesys_next does not set %r28 to -ENOSYS
328 * when %r20 is set to -1, initialize it here.
330 regs->gr[28] = -ENOSYS;
334 * A nonzero return code from
335 * tracehook_report_syscall_entry() tells us
336 * to prevent the syscall execution. Skip
337 * the syscall call and the syscall restart handling.
339 * Note that the tracer may also just change
340 * regs->gr[20] to an invalid syscall number,
341 * that is handled by tracesys_next.
348 /* Do the secure computing check after ptrace. */
349 if (secure_computing(NULL) == -1)
352 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
353 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
354 trace_sys_enter(regs, regs->gr[20]);
358 if (!is_compat_task())
359 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
360 regs->gr[24], regs->gr[23]);
363 audit_syscall_entry(regs->gr[20] & 0xffffffff,
364 regs->gr[26] & 0xffffffff,
365 regs->gr[25] & 0xffffffff,
366 regs->gr[24] & 0xffffffff,
367 regs->gr[23] & 0xffffffff);
370 * Sign extend the syscall number to 64bit since it may have been
371 * modified by a compat ptrace call
373 return (int) ((u32) regs->gr[20]);
376 void do_syscall_trace_exit(struct pt_regs *regs)
378 int stepping = test_thread_flag(TIF_SINGLESTEP) ||
379 test_thread_flag(TIF_BLOCKSTEP);
381 audit_syscall_exit(regs);
383 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
384 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
385 trace_sys_exit(regs, regs->gr[20]);
388 if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
389 tracehook_report_syscall_exit(regs, stepping);
397 static int fpr_get(struct task_struct *target,
398 const struct user_regset *regset,
399 unsigned int pos, unsigned int count,
400 void *kbuf, void __user *ubuf)
402 struct pt_regs *regs = task_regs(target);
404 __u64 __user *u = ubuf;
408 count /= sizeof(reg);
411 for (; count > 0 && pos < ELF_NFPREG; --count)
412 *k++ = regs->fr[pos++];
414 for (; count > 0 && pos < ELF_NFPREG; --count)
415 if (__put_user(regs->fr[pos++], u++))
421 count *= sizeof(reg);
422 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
423 ELF_NFPREG * sizeof(reg), -1);
426 static int fpr_set(struct task_struct *target,
427 const struct user_regset *regset,
428 unsigned int pos, unsigned int count,
429 const void *kbuf, const void __user *ubuf)
431 struct pt_regs *regs = task_regs(target);
432 const __u64 *k = kbuf;
433 const __u64 __user *u = ubuf;
437 count /= sizeof(reg);
440 for (; count > 0 && pos < ELF_NFPREG; --count)
441 regs->fr[pos++] = *k++;
443 for (; count > 0 && pos < ELF_NFPREG; --count) {
444 if (__get_user(reg, u++))
446 regs->fr[pos++] = reg;
452 count *= sizeof(reg);
453 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
454 ELF_NFPREG * sizeof(reg), -1);
457 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
459 static unsigned long get_reg(struct pt_regs *regs, int num)
462 case RI(gr[0]) ... RI(gr[31]): return regs->gr[num - RI(gr[0])];
463 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
464 case RI(iasq[0]): return regs->iasq[0];
465 case RI(iasq[1]): return regs->iasq[1];
466 case RI(iaoq[0]): return regs->iaoq[0];
467 case RI(iaoq[1]): return regs->iaoq[1];
468 case RI(sar): return regs->sar;
469 case RI(iir): return regs->iir;
470 case RI(isr): return regs->isr;
471 case RI(ior): return regs->ior;
472 case RI(ipsw): return regs->ipsw;
473 case RI(cr27): return regs->cr27;
474 case RI(cr0): return mfctl(0);
475 case RI(cr24): return mfctl(24);
476 case RI(cr25): return mfctl(25);
477 case RI(cr26): return mfctl(26);
478 case RI(cr28): return mfctl(28);
479 case RI(cr29): return mfctl(29);
480 case RI(cr30): return mfctl(30);
481 case RI(cr31): return mfctl(31);
482 case RI(cr8): return mfctl(8);
483 case RI(cr9): return mfctl(9);
484 case RI(cr12): return mfctl(12);
485 case RI(cr13): return mfctl(13);
486 case RI(cr10): return mfctl(10);
487 case RI(cr15): return mfctl(15);
492 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
497 * Allow writing to Nullify, Divide-step-correction,
498 * and carry/borrow bits.
499 * BEWARE, if you set N, and then single step, it won't
500 * stop on the nullified instruction.
502 val &= USER_PSW_BITS;
503 regs->gr[0] &= ~USER_PSW_BITS;
506 case RI(gr[1]) ... RI(gr[31]):
507 regs->gr[num - RI(gr[0])] = val;
511 /* set 2 lowest bits to ensure userspace privilege: */
512 regs->iaoq[num - RI(iaoq[0])] = val | 3;
514 case RI(sar): regs->sar = val;
518 /* do not allow to change any of the following registers (yet) */
519 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
520 case RI(iasq[0]): return regs->iasq[0];
521 case RI(iasq[1]): return regs->iasq[1];
522 case RI(iir): return regs->iir;
523 case RI(isr): return regs->isr;
524 case RI(ior): return regs->ior;
525 case RI(ipsw): return regs->ipsw;
526 case RI(cr27): return regs->cr27;
527 case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
528 case cr8, cr9, cr12, cr13, cr10, cr15;
533 static int gpr_get(struct task_struct *target,
534 const struct user_regset *regset,
535 unsigned int pos, unsigned int count,
536 void *kbuf, void __user *ubuf)
538 struct pt_regs *regs = task_regs(target);
539 unsigned long *k = kbuf;
540 unsigned long __user *u = ubuf;
544 count /= sizeof(reg);
547 for (; count > 0 && pos < ELF_NGREG; --count)
548 *k++ = get_reg(regs, pos++);
550 for (; count > 0 && pos < ELF_NGREG; --count)
551 if (__put_user(get_reg(regs, pos++), u++))
556 count *= sizeof(reg);
557 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
558 ELF_NGREG * sizeof(reg), -1);
561 static int gpr_set(struct task_struct *target,
562 const struct user_regset *regset,
563 unsigned int pos, unsigned int count,
564 const void *kbuf, const void __user *ubuf)
566 struct pt_regs *regs = task_regs(target);
567 const unsigned long *k = kbuf;
568 const unsigned long __user *u = ubuf;
572 count /= sizeof(reg);
575 for (; count > 0 && pos < ELF_NGREG; --count)
576 set_reg(regs, pos++, *k++);
578 for (; count > 0 && pos < ELF_NGREG; --count) {
579 if (__get_user(reg, u++))
581 set_reg(regs, pos++, reg);
587 count *= sizeof(reg);
588 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
589 ELF_NGREG * sizeof(reg), -1);
592 static const struct user_regset native_regsets[] = {
594 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
595 .size = sizeof(long), .align = sizeof(long),
596 .get = gpr_get, .set = gpr_set
599 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
600 .size = sizeof(__u64), .align = sizeof(__u64),
601 .get = fpr_get, .set = fpr_set
605 static const struct user_regset_view user_parisc_native_view = {
606 .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
607 .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
611 #include <linux/compat.h>
613 static int gpr32_get(struct task_struct *target,
614 const struct user_regset *regset,
615 unsigned int pos, unsigned int count,
616 void *kbuf, void __user *ubuf)
618 struct pt_regs *regs = task_regs(target);
619 compat_ulong_t *k = kbuf;
620 compat_ulong_t __user *u = ubuf;
624 count /= sizeof(reg);
627 for (; count > 0 && pos < ELF_NGREG; --count)
628 *k++ = get_reg(regs, pos++);
630 for (; count > 0 && pos < ELF_NGREG; --count)
631 if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
637 count *= sizeof(reg);
638 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
639 ELF_NGREG * sizeof(reg), -1);
642 static int gpr32_set(struct task_struct *target,
643 const struct user_regset *regset,
644 unsigned int pos, unsigned int count,
645 const void *kbuf, const void __user *ubuf)
647 struct pt_regs *regs = task_regs(target);
648 const compat_ulong_t *k = kbuf;
649 const compat_ulong_t __user *u = ubuf;
653 count /= sizeof(reg);
656 for (; count > 0 && pos < ELF_NGREG; --count)
657 set_reg(regs, pos++, *k++);
659 for (; count > 0 && pos < ELF_NGREG; --count) {
660 if (__get_user(reg, u++))
662 set_reg(regs, pos++, reg);
668 count *= sizeof(reg);
669 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
670 ELF_NGREG * sizeof(reg), -1);
674 * These are the regset flavors matching the 32bit native set.
676 static const struct user_regset compat_regsets[] = {
678 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
679 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
680 .get = gpr32_get, .set = gpr32_set
683 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
684 .size = sizeof(__u64), .align = sizeof(__u64),
685 .get = fpr_get, .set = fpr_set
689 static const struct user_regset_view user_parisc_compat_view = {
690 .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
691 .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
693 #endif /* CONFIG_64BIT */
695 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
697 BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
698 BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
700 if (is_compat_task())
701 return &user_parisc_compat_view;
703 return &user_parisc_native_view;