1 // SPDX-License-Identifier: GPL-2.0
3 * linux/arch/m32r/kernel/ptrace.c
5 * Copyright (C) 2002 Hirokazu Takata, Takeo Takahashi
6 * Copyright (C) 2004 Hirokazu Takata, Kei Sakamoto
8 * Original x86 implementation:
10 * edited by Linus Torvalds
12 * Some code taken from sh version:
13 * Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka
14 * Some code taken from arm version:
15 * Copyright (C) 2000 Russell King
18 #include <linux/kernel.h>
19 #include <linux/sched.h>
20 #include <linux/sched/task_stack.h>
22 #include <linux/err.h>
23 #include <linux/smp.h>
24 #include <linux/errno.h>
25 #include <linux/ptrace.h>
26 #include <linux/user.h>
27 #include <linux/string.h>
28 #include <linux/signal.h>
30 #include <asm/cacheflush.h>
32 #include <linux/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/processor.h>
35 #include <asm/mmu_context.h>
38 * This routine will get a word off of the process kernel stack.
40 static inline unsigned long int
41 get_stack_long(struct task_struct *task, int offset)
45 stack = (unsigned long *)task_pt_regs(task);
51 * This routine will put a word on the process kernel stack.
54 put_stack_long(struct task_struct *task, int offset, unsigned long data)
58 stack = (unsigned long *)task_pt_regs(task);
64 static int reg_offset[] = {
65 PT_R0, PT_R1, PT_R2, PT_R3, PT_R4, PT_R5, PT_R6, PT_R7,
66 PT_R8, PT_R9, PT_R10, PT_R11, PT_R12, PT_FP, PT_LR, PT_SPU,
70 * Read the word at offset "off" into the "struct user". We
71 * actually access the pt_regs stored on the kernel stack.
73 static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
74 unsigned long __user *data)
78 struct user * dummy = NULL;
81 if ((off & 3) || off > sizeof(struct user) - 3)
87 __asm__ __volatile__ (
94 psw = get_stack_long(tsk, PT_PSW);
95 tmp = ((psw >> 8) & 1);
99 unsigned long psw, bbpsw;
100 psw = get_stack_long(tsk, PT_PSW);
101 bbpsw = get_stack_long(tsk, PT_BBPSW);
102 tmp = ((psw >> 8) & 0xff) | ((bbpsw & 0xff) << 8);
106 tmp = get_stack_long(tsk, PT_BPC);
112 if (off < (sizeof(struct pt_regs) >> 2))
113 tmp = get_stack_long(tsk, off);
115 else if (off >= (long)(&dummy->fpu >> 2) &&
116 off < (long)(&dummy->u_fpvalid >> 2)) {
117 if (!tsk_used_math(tsk)) {
118 if (off == (long)(&dummy->fpu.fpscr >> 2))
123 tmp = ((long *)(&tsk->thread.fpu >> 2))
124 [off - (long)&dummy->fpu];
125 } else if (off == (long)(&dummy->u_fpvalid >> 2))
126 tmp = !!tsk_used_math(tsk);
127 #endif /* not NO_FPU */
132 return put_user(tmp, data);
135 static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
140 struct user * dummy = NULL;
143 if ((off & 3) || off > sizeof(struct user) - 3)
151 /* We don't allow to modify evb. */
156 /* We allow to modify only cbr in psw */
158 psw = get_stack_long(tsk, PT_PSW);
159 psw = (psw & ~0x100) | ((data & 1) << 8);
160 ret = put_stack_long(tsk, PT_PSW, psw);
168 if (off < (sizeof(struct pt_regs) >> 2))
169 ret = put_stack_long(tsk, off, data);
171 else if (off >= (long)(&dummy->fpu >> 2) &&
172 off < (long)(&dummy->u_fpvalid >> 2)) {
173 set_stopped_child_used_math(tsk);
174 ((long *)&tsk->thread.fpu)
175 [off - (long)&dummy->fpu] = data;
177 } else if (off == (long)(&dummy->u_fpvalid >> 2)) {
178 conditional_stopped_child_used_math(data, tsk);
181 #endif /* not NO_FPU */
189 * Get all user integer registers.
191 static int ptrace_getregs(struct task_struct *tsk, void __user *uregs)
193 struct pt_regs *regs = task_pt_regs(tsk);
195 return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0;
199 * Set all user integer registers.
201 static int ptrace_setregs(struct task_struct *tsk, void __user *uregs)
203 struct pt_regs newregs;
207 if (copy_from_user(&newregs, uregs, sizeof(struct pt_regs)) == 0) {
208 struct pt_regs *regs = task_pt_regs(tsk);
218 check_condition_bit(struct task_struct *child)
220 return (int)((get_stack_long(child, PT_PSW) >> 8) & 1);
224 check_condition_src(unsigned long op, unsigned long regno1,
225 unsigned long regno2, struct task_struct *child)
227 unsigned long reg1, reg2;
229 reg2 = get_stack_long(child, reg_offset[regno2]);
233 reg1 = get_stack_long(child, reg_offset[regno1]);
236 reg1 = get_stack_long(child, reg_offset[regno1]);
243 return (int)reg2 < 0;
245 return (int)reg2 >= 0;
247 return (int)reg2 <= 0;
249 return (int)reg2 > 0;
257 compute_next_pc_for_16bit_insn(unsigned long insn, unsigned long pc,
258 unsigned long *next_pc,
259 struct task_struct *child)
261 unsigned long op, op2, op3;
266 if (insn & 0x00008000)
269 insn &= 0x7fff; /* right slot */
271 insn >>= 16; /* left slot */
273 op = (insn >> 12) & 0xf;
274 op2 = (insn >> 8) & 0xf;
275 op3 = (insn >> 4) & 0xf;
281 if (!check_condition_bit(child)) {
282 disp = (long)(insn << 24) >> 22;
283 *next_pc = (pc & ~0x3) + disp;
289 if (check_condition_bit(child)) {
290 disp = (long)(insn << 24) >> 22;
291 *next_pc = (pc & ~0x3) + disp;
297 disp = (long)(insn << 24) >> 22;
298 *next_pc = (pc & ~0x3) + disp;
302 } else if (op == 0x1) {
305 if (op3 == 0xf) { /* TRAP */
309 /* kernel space is not allowed as next_pc */
311 unsigned long trapno;
313 __asm__ __volatile__ (
318 *next_pc = evb + (trapno << 2);
321 } else if (op3 == 0xd) { /* RTE */
322 *next_pc = get_stack_long(child, PT_BPC);
327 if (op3 == 0xc && check_condition_bit(child)) {
329 *next_pc = get_stack_long(child,
335 if (op3 == 0xc && !check_condition_bit(child)) {
337 *next_pc = get_stack_long(child,
344 if (op3 == 0xc) { /* JMP */
346 *next_pc = get_stack_long(child,
360 compute_next_pc_for_32bit_insn(unsigned long insn, unsigned long pc,
361 unsigned long *next_pc,
362 struct task_struct *child)
367 unsigned long regno1, regno2;
369 op = (insn >> 28) & 0xf;
370 if (op == 0xf) { /* branch 24-bit relative */
371 op2 = (insn >> 24) & 0xf;
375 if (!check_condition_bit(child)) {
376 disp = (long)(insn << 8) >> 6;
377 *next_pc = (pc & ~0x3) + disp;
383 if (check_condition_bit(child)) {
384 disp = (long)(insn << 8) >> 6;
385 *next_pc = (pc & ~0x3) + disp;
391 disp = (long)(insn << 8) >> 6;
392 *next_pc = (pc & ~0x3) + disp;
395 } else if (op == 0xb) { /* branch 16-bit relative */
396 op2 = (insn >> 20) & 0xf;
406 regno1 = ((insn >> 24) & 0xf);
407 regno2 = ((insn >> 16) & 0xf);
408 if (check_condition_src(op2, regno1, regno2, child)) {
409 disp = (long)(insn << 16) >> 14;
410 *next_pc = (pc & ~0x3) + disp;
420 compute_next_pc(unsigned long insn, unsigned long pc,
421 unsigned long *next_pc, struct task_struct *child)
423 if (insn & 0x80000000)
424 compute_next_pc_for_32bit_insn(insn, pc, next_pc, child);
426 compute_next_pc_for_16bit_insn(insn, pc, next_pc, child);
430 register_debug_trap(struct task_struct *child, unsigned long next_pc,
431 unsigned long next_insn, unsigned long *code)
433 struct debug_trap *p = &child->thread.debug_trap;
434 unsigned long addr = next_pc & ~3;
436 if (p->nr_trap == MAX_TRAPS) {
437 printk("kernel BUG at %s %d: p->nr_trap = %d\n",
438 __FILE__, __LINE__, p->nr_trap);
441 p->addr[p->nr_trap] = addr;
442 p->insn[p->nr_trap] = next_insn;
445 *code = (next_insn & 0xffff0000) | 0x10f1;
448 if ((next_insn & 0x80000000) || (next_insn & 0x8000)) {
452 *code = (next_insn & 0xffff) | 0x10f10000;
460 unregister_debug_trap(struct task_struct *child, unsigned long addr,
463 struct debug_trap *p = &child->thread.debug_trap;
466 /* Search debug trap entry. */
467 for (i = 0; i < p->nr_trap; i++) {
468 if (p->addr[i] == addr)
471 if (i >= p->nr_trap) {
472 /* The trap may be requested from debugger.
473 * ptrace should do nothing in this case.
478 /* Recover original instruction code. */
481 /* Shift debug trap entries. */
482 while (i < p->nr_trap - 1) {
483 p->insn[i] = p->insn[i + 1];
484 p->addr[i] = p->addr[i + 1];
492 unregister_all_debug_traps(struct task_struct *child)
494 struct debug_trap *p = &child->thread.debug_trap;
497 for (i = 0; i < p->nr_trap; i++)
498 access_process_vm(child, p->addr[i], &p->insn[i], sizeof(p->insn[i]),
499 FOLL_FORCE | FOLL_WRITE);
504 invalidate_cache(void)
506 #if defined(CONFIG_CHIP_M32700) || defined(CONFIG_CHIP_OPSP)
508 _flush_cache_copyback_all();
510 #else /* ! CONFIG_CHIP_M32700 */
512 /* Invalidate cache */
513 __asm__ __volatile__ (
516 "stb r1, @r0 ; cache off \n\t"
520 "stb r1, @r0 ; cache invalidate \n\t"
523 "ldb r1, @r0 ; invalidate check \n\t"
528 "stb r1, @r0 ; cache on \n\t"
529 : : : "r0", "r1", "memory"
531 /* FIXME: copying-back d-cache and invalidating i-cache are needed.
533 #endif /* CONFIG_CHIP_M32700 */
536 /* Embed a debug trap (TRAP1) code */
538 embed_debug_trap(struct task_struct *child, unsigned long next_pc)
540 unsigned long next_insn, code;
541 unsigned long addr = next_pc & ~3;
543 if (access_process_vm(child, addr, &next_insn, sizeof(next_insn),
545 != sizeof(next_insn)) {
546 return -1; /* error */
549 /* Set a trap code. */
550 if (register_debug_trap(child, next_pc, next_insn, &code)) {
551 return -1; /* error */
553 if (access_process_vm(child, addr, &code, sizeof(code),
554 FOLL_FORCE | FOLL_WRITE)
556 return -1; /* error */
558 return 0; /* success */
562 withdraw_debug_trap(struct pt_regs *regs)
567 addr = (regs->bpc - 2) & ~3;
569 if (unregister_debug_trap(current, addr, &code)) {
570 access_process_vm(current, addr, &code, sizeof(code),
571 FOLL_FORCE | FOLL_WRITE);
577 init_debug_traps(struct task_struct *child)
579 struct debug_trap *p = &child->thread.debug_trap;
582 for (i = 0; i < MAX_TRAPS; i++) {
588 void user_enable_single_step(struct task_struct *child)
590 unsigned long next_pc;
591 unsigned long pc, insn;
593 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
595 /* Compute next pc. */
596 pc = get_stack_long(child, PT_BPC);
598 if (access_process_vm(child, pc&~3, &insn, sizeof(insn),
603 compute_next_pc(insn, pc, &next_pc, child);
604 if (next_pc & 0x80000000)
607 if (embed_debug_trap(child, next_pc))
613 void user_disable_single_step(struct task_struct *child)
615 unregister_all_debug_traps(child);
620 * Called by kernel/ptrace.c when detaching..
622 * Make sure single step bits etc are not set.
624 void ptrace_disable(struct task_struct *child)
626 /* nothing to do.. */
630 arch_ptrace(struct task_struct *child, long request,
631 unsigned long addr, unsigned long data)
634 unsigned long __user *datap = (unsigned long __user *) data;
638 * read word at location "addr" in the child process.
640 case PTRACE_PEEKTEXT:
641 case PTRACE_PEEKDATA:
642 ret = generic_ptrace_peekdata(child, addr, data);
646 * read the word at location addr in the USER area.
649 ret = ptrace_read_user(child, addr, datap);
653 * write the word at location addr.
655 case PTRACE_POKETEXT:
656 case PTRACE_POKEDATA:
657 ret = generic_ptrace_pokedata(child, addr, data);
658 if (ret == 0 && request == PTRACE_POKETEXT)
663 * write the word at location addr in the USER area.
666 ret = ptrace_write_user(child, addr, data);
670 ret = ptrace_getregs(child, datap);
674 ret = ptrace_setregs(child, datap);
678 ret = ptrace_request(child, request, addr, data);
685 /* notification of system call entry/exit
686 * - triggered by current->work.syscall_trace
688 void do_syscall_trace(void)
690 if (!test_thread_flag(TIF_SYSCALL_TRACE))
692 if (!(current->ptrace & PT_PTRACED))
694 /* the 0x80 provides a way for the tracing parent to distinguish
695 between a syscall stop and SIGTRAP delivery */
696 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
700 * this isn't the same as continuing with a signal, but it will do
701 * for normal use. strace only continues with a signal if the
702 * stopping signal is not SIGTRAP. -brl
704 if (current->exit_code) {
705 send_sig(current->exit_code, current, 1);
706 current->exit_code = 0;