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_GR1 && addr <= PT_GR31) ||
175 addr == PT_IAOQ0 || addr == PT_IAOQ1 ||
176 (addr >= PT_FR0 && addr <= PT_FR31 + 4) ||
178 *(unsigned long *) ((char *) task_regs(child) + addr) = data;
183 case PTRACE_GETREGS: /* Get all gp regs from the child. */
184 return copy_regset_to_user(child,
185 task_user_regset_view(current),
187 0, sizeof(struct user_regs_struct),
190 case PTRACE_SETREGS: /* Set all gp regs in the child. */
191 return copy_regset_from_user(child,
192 task_user_regset_view(current),
194 0, sizeof(struct user_regs_struct),
197 case PTRACE_GETFPREGS: /* Get the child FPU state. */
198 return copy_regset_to_user(child,
199 task_user_regset_view(current),
201 0, sizeof(struct user_fp_struct),
204 case PTRACE_SETFPREGS: /* Set the child FPU state. */
205 return copy_regset_from_user(child,
206 task_user_regset_view(current),
208 0, sizeof(struct user_fp_struct),
212 ret = ptrace_request(child, request, addr, data);
222 /* This function is needed to translate 32 bit pt_regs offsets in to
223 * 64 bit pt_regs offsets. For example, a 32 bit gdb under a 64 bit kernel
224 * will request offset 12 if it wants gr3, but the lower 32 bits of
225 * the 64 bit kernels view of gr3 will be at offset 28 (3*8 + 4).
226 * This code relies on a 32 bit pt_regs being comprised of 32 bit values
227 * except for the fp registers which (a) are 64 bits, and (b) follow
228 * the gr registers at the start of pt_regs. The 32 bit pt_regs should
229 * be half the size of the 64 bit pt_regs, plus 32*4 to allow for fr[]
230 * being 64 bit in both cases.
233 static compat_ulong_t translate_usr_offset(compat_ulong_t offset)
236 return sizeof(struct pt_regs);
237 else if (offset <= 32*4) /* gr[0..31] */
238 return offset * 2 + 4;
239 else if (offset <= 32*4+32*8) /* gr[0..31] + fr[0..31] */
240 return offset + 32*4;
241 else if (offset < sizeof(struct pt_regs)/2 + 32*4)
242 return offset * 2 + 4 - 32*8;
244 return sizeof(struct pt_regs);
247 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
248 compat_ulong_t addr, compat_ulong_t data)
256 if (addr & (sizeof(compat_uint_t)-1))
258 addr = translate_usr_offset(addr);
259 if (addr >= sizeof(struct pt_regs))
262 tmp = *(compat_uint_t *) ((char *) task_regs(child) + addr);
263 ret = put_user(tmp, (compat_uint_t *) (unsigned long) data);
266 /* Write the word at location addr in the USER area. This will need
267 to change when the kernel no longer saves all regs on a syscall.
268 FIXME. There is a problem at the moment in that r3-r18 are only
269 saved if the process is ptraced on syscall entry, and even then
270 those values are overwritten by actual register values on syscall
273 /* Some register values written here may be ignored in
274 * entry.S:syscall_restore_rfi; e.g. iaoq is written with
275 * r31/r31+4, and not with the values in pt_regs.
277 if (addr == PT_PSW) {
278 /* Since PT_PSW==0, it is valid for 32 bit processes
279 * under 64 bit kernels as well.
281 ret = arch_ptrace(child, request, addr, data);
283 if (addr & (sizeof(compat_uint_t)-1))
285 addr = translate_usr_offset(addr);
286 if (addr >= sizeof(struct pt_regs))
288 if (addr >= PT_FR0 && addr <= PT_FR31 + 4) {
289 /* Special case, fp regs are 64 bits anyway */
290 *(__u64 *) ((char *) task_regs(child) + addr) = data;
293 else if ((addr >= PT_GR1+4 && addr <= PT_GR31+4) ||
294 addr == PT_IAOQ0+4 || addr == PT_IAOQ1+4 ||
296 /* Zero the top 32 bits */
297 *(__u32 *) ((char *) task_regs(child) + addr - 4) = 0;
298 *(__u32 *) ((char *) task_regs(child) + addr) = data;
305 ret = compat_ptrace_request(child, request, addr, data);
313 long do_syscall_trace_enter(struct pt_regs *regs)
315 if (test_thread_flag(TIF_SYSCALL_TRACE) &&
316 tracehook_report_syscall_entry(regs)) {
318 * Tracing decided this syscall should not happen or the
319 * debugger stored an invalid system call number. Skip
320 * the system call and the system call restart handling.
326 /* Do the secure computing check after ptrace. */
327 if (secure_computing(NULL) == -1)
330 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
331 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
332 trace_sys_enter(regs, regs->gr[20]);
336 if (!is_compat_task())
337 audit_syscall_entry(regs->gr[20], regs->gr[26], regs->gr[25],
338 regs->gr[24], regs->gr[23]);
341 audit_syscall_entry(regs->gr[20] & 0xffffffff,
342 regs->gr[26] & 0xffffffff,
343 regs->gr[25] & 0xffffffff,
344 regs->gr[24] & 0xffffffff,
345 regs->gr[23] & 0xffffffff);
349 * Sign extend the syscall number to 64bit since it may have been
350 * modified by a compat ptrace call
352 return (int) ((u32) regs->gr[20]);
355 void do_syscall_trace_exit(struct pt_regs *regs)
357 int stepping = test_thread_flag(TIF_SINGLESTEP) ||
358 test_thread_flag(TIF_BLOCKSTEP);
360 audit_syscall_exit(regs);
362 #ifdef CONFIG_HAVE_SYSCALL_TRACEPOINTS
363 if (unlikely(test_thread_flag(TIF_SYSCALL_TRACEPOINT)))
364 trace_sys_exit(regs, regs->gr[20]);
367 if (stepping || test_thread_flag(TIF_SYSCALL_TRACE))
368 tracehook_report_syscall_exit(regs, stepping);
376 static int fpr_get(struct task_struct *target,
377 const struct user_regset *regset,
378 unsigned int pos, unsigned int count,
379 void *kbuf, void __user *ubuf)
381 struct pt_regs *regs = task_regs(target);
383 __u64 __user *u = ubuf;
387 count /= sizeof(reg);
390 for (; count > 0 && pos < ELF_NFPREG; --count)
391 *k++ = regs->fr[pos++];
393 for (; count > 0 && pos < ELF_NFPREG; --count)
394 if (__put_user(regs->fr[pos++], u++))
400 count *= sizeof(reg);
401 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
402 ELF_NFPREG * sizeof(reg), -1);
405 static int fpr_set(struct task_struct *target,
406 const struct user_regset *regset,
407 unsigned int pos, unsigned int count,
408 const void *kbuf, const void __user *ubuf)
410 struct pt_regs *regs = task_regs(target);
411 const __u64 *k = kbuf;
412 const __u64 __user *u = ubuf;
416 count /= sizeof(reg);
419 for (; count > 0 && pos < ELF_NFPREG; --count)
420 regs->fr[pos++] = *k++;
422 for (; count > 0 && pos < ELF_NFPREG; --count) {
423 if (__get_user(reg, u++))
425 regs->fr[pos++] = reg;
431 count *= sizeof(reg);
432 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
433 ELF_NFPREG * sizeof(reg), -1);
436 #define RI(reg) (offsetof(struct user_regs_struct,reg) / sizeof(long))
438 static unsigned long get_reg(struct pt_regs *regs, int num)
441 case RI(gr[0]) ... RI(gr[31]): return regs->gr[num - RI(gr[0])];
442 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
443 case RI(iasq[0]): return regs->iasq[0];
444 case RI(iasq[1]): return regs->iasq[1];
445 case RI(iaoq[0]): return regs->iaoq[0];
446 case RI(iaoq[1]): return regs->iaoq[1];
447 case RI(sar): return regs->sar;
448 case RI(iir): return regs->iir;
449 case RI(isr): return regs->isr;
450 case RI(ior): return regs->ior;
451 case RI(ipsw): return regs->ipsw;
452 case RI(cr27): return regs->cr27;
453 case RI(cr0): return mfctl(0);
454 case RI(cr24): return mfctl(24);
455 case RI(cr25): return mfctl(25);
456 case RI(cr26): return mfctl(26);
457 case RI(cr28): return mfctl(28);
458 case RI(cr29): return mfctl(29);
459 case RI(cr30): return mfctl(30);
460 case RI(cr31): return mfctl(31);
461 case RI(cr8): return mfctl(8);
462 case RI(cr9): return mfctl(9);
463 case RI(cr12): return mfctl(12);
464 case RI(cr13): return mfctl(13);
465 case RI(cr10): return mfctl(10);
466 case RI(cr15): return mfctl(15);
471 static void set_reg(struct pt_regs *regs, int num, unsigned long val)
476 * Allow writing to Nullify, Divide-step-correction,
477 * and carry/borrow bits.
478 * BEWARE, if you set N, and then single step, it won't
479 * stop on the nullified instruction.
481 val &= USER_PSW_BITS;
482 regs->gr[0] &= ~USER_PSW_BITS;
485 case RI(gr[1]) ... RI(gr[31]):
486 regs->gr[num - RI(gr[0])] = val;
490 regs->iaoq[num - RI(iaoq[0])] = val;
492 case RI(sar): regs->sar = val;
496 /* do not allow to change any of the following registers (yet) */
497 case RI(sr[0]) ... RI(sr[7]): return regs->sr[num - RI(sr[0])];
498 case RI(iasq[0]): return regs->iasq[0];
499 case RI(iasq[1]): return regs->iasq[1];
500 case RI(iir): return regs->iir;
501 case RI(isr): return regs->isr;
502 case RI(ior): return regs->ior;
503 case RI(ipsw): return regs->ipsw;
504 case RI(cr27): return regs->cr27;
505 case cr0, cr24, cr25, cr26, cr27, cr28, cr29, cr30, cr31;
506 case cr8, cr9, cr12, cr13, cr10, cr15;
511 static int gpr_get(struct task_struct *target,
512 const struct user_regset *regset,
513 unsigned int pos, unsigned int count,
514 void *kbuf, void __user *ubuf)
516 struct pt_regs *regs = task_regs(target);
517 unsigned long *k = kbuf;
518 unsigned long __user *u = ubuf;
522 count /= sizeof(reg);
525 for (; count > 0 && pos < ELF_NGREG; --count)
526 *k++ = get_reg(regs, pos++);
528 for (; count > 0 && pos < ELF_NGREG; --count)
529 if (__put_user(get_reg(regs, pos++), u++))
534 count *= sizeof(reg);
535 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
536 ELF_NGREG * sizeof(reg), -1);
539 static int gpr_set(struct task_struct *target,
540 const struct user_regset *regset,
541 unsigned int pos, unsigned int count,
542 const void *kbuf, const void __user *ubuf)
544 struct pt_regs *regs = task_regs(target);
545 const unsigned long *k = kbuf;
546 const unsigned long __user *u = ubuf;
550 count /= sizeof(reg);
553 for (; count > 0 && pos < ELF_NGREG; --count)
554 set_reg(regs, pos++, *k++);
556 for (; count > 0 && pos < ELF_NGREG; --count) {
557 if (__get_user(reg, u++))
559 set_reg(regs, pos++, reg);
565 count *= sizeof(reg);
566 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
567 ELF_NGREG * sizeof(reg), -1);
570 static const struct user_regset native_regsets[] = {
572 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
573 .size = sizeof(long), .align = sizeof(long),
574 .get = gpr_get, .set = gpr_set
577 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
578 .size = sizeof(__u64), .align = sizeof(__u64),
579 .get = fpr_get, .set = fpr_set
583 static const struct user_regset_view user_parisc_native_view = {
584 .name = "parisc", .e_machine = ELF_ARCH, .ei_osabi = ELFOSABI_LINUX,
585 .regsets = native_regsets, .n = ARRAY_SIZE(native_regsets)
589 #include <linux/compat.h>
591 static int gpr32_get(struct task_struct *target,
592 const struct user_regset *regset,
593 unsigned int pos, unsigned int count,
594 void *kbuf, void __user *ubuf)
596 struct pt_regs *regs = task_regs(target);
597 compat_ulong_t *k = kbuf;
598 compat_ulong_t __user *u = ubuf;
602 count /= sizeof(reg);
605 for (; count > 0 && pos < ELF_NGREG; --count)
606 *k++ = get_reg(regs, pos++);
608 for (; count > 0 && pos < ELF_NGREG; --count)
609 if (__put_user((compat_ulong_t) get_reg(regs, pos++), u++))
615 count *= sizeof(reg);
616 return user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
617 ELF_NGREG * sizeof(reg), -1);
620 static int gpr32_set(struct task_struct *target,
621 const struct user_regset *regset,
622 unsigned int pos, unsigned int count,
623 const void *kbuf, const void __user *ubuf)
625 struct pt_regs *regs = task_regs(target);
626 const compat_ulong_t *k = kbuf;
627 const compat_ulong_t __user *u = ubuf;
631 count /= sizeof(reg);
634 for (; count > 0 && pos < ELF_NGREG; --count)
635 set_reg(regs, pos++, *k++);
637 for (; count > 0 && pos < ELF_NGREG; --count) {
638 if (__get_user(reg, u++))
640 set_reg(regs, pos++, reg);
646 count *= sizeof(reg);
647 return user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
648 ELF_NGREG * sizeof(reg), -1);
652 * These are the regset flavors matching the 32bit native set.
654 static const struct user_regset compat_regsets[] = {
656 .core_note_type = NT_PRSTATUS, .n = ELF_NGREG,
657 .size = sizeof(compat_long_t), .align = sizeof(compat_long_t),
658 .get = gpr32_get, .set = gpr32_set
661 .core_note_type = NT_PRFPREG, .n = ELF_NFPREG,
662 .size = sizeof(__u64), .align = sizeof(__u64),
663 .get = fpr_get, .set = fpr_set
667 static const struct user_regset_view user_parisc_compat_view = {
668 .name = "parisc", .e_machine = EM_PARISC, .ei_osabi = ELFOSABI_LINUX,
669 .regsets = compat_regsets, .n = ARRAY_SIZE(compat_regsets)
671 #endif /* CONFIG_64BIT */
673 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
675 BUILD_BUG_ON(sizeof(struct user_regs_struct)/sizeof(long) != ELF_NGREG);
676 BUILD_BUG_ON(sizeof(struct user_fp_struct)/sizeof(__u64) != ELF_NFPREG);
678 if (is_compat_task())
679 return &user_parisc_compat_view;
681 return &user_parisc_native_view;