linux/arch/m68k/kernel/ptrace.c
Greg Ungerer bd53e442e8 m68knommu: implement minimal regset support
Add code support to the m68k architecture for regsets.

Currently the only thing that will need to use regsets for m68k will be
coredump support of the elf_fdpic loader. So the changes are conditional
on that. The added support is the minimum definitions required to support
just that.

Signed-off-by: Greg Ungerer <gerg@linux-m68k.org>
2022-05-16 13:18:30 +10:00

352 lines
8.4 KiB
C

/*
* linux/arch/m68k/kernel/ptrace.c
*
* Copyright (C) 1994 by Hamish Macdonald
* Taken from linux/kernel/ptrace.c and modified for M680x0.
* linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
*
* This file is subject to the terms and conditions of the GNU General
* Public License. See the file COPYING in the main directory of
* this archive for more details.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/sched/task_stack.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/signal.h>
#include <linux/regset.h>
#include <linux/elf.h>
#include <linux/uaccess.h>
#include <asm/page.h>
#include <asm/processor.h>
/*
* does not yet catch signals sent when the child dies.
* in exit.c or in signal.c.
*/
/* determines which bits in the SR the user has access to. */
/* 1 = access 0 = no access */
#define SR_MASK 0x001f
/* sets the trace bits. */
#define TRACE_BITS 0xC000
#define T1_BIT 0x8000
#define T0_BIT 0x4000
/* Find the stack offset for a register, relative to thread.esp0. */
#define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
#define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \
- sizeof(struct switch_stack))
/* Mapping from PT_xxx to the stack offset at which the register is
saved. Notice that usp has no stack-slot and needs to be treated
specially (see get_reg/put_reg below). */
static const int regoff[] = {
[0] = PT_REG(d1),
[1] = PT_REG(d2),
[2] = PT_REG(d3),
[3] = PT_REG(d4),
[4] = PT_REG(d5),
[5] = SW_REG(d6),
[6] = SW_REG(d7),
[7] = PT_REG(a0),
[8] = PT_REG(a1),
[9] = PT_REG(a2),
[10] = SW_REG(a3),
[11] = SW_REG(a4),
[12] = SW_REG(a5),
[13] = SW_REG(a6),
[14] = PT_REG(d0),
[15] = -1,
[16] = PT_REG(orig_d0),
[17] = PT_REG(sr),
[18] = PT_REG(pc),
};
/*
* Get contents of register REGNO in task TASK.
*/
static inline long get_reg(struct task_struct *task, int regno)
{
unsigned long *addr;
if (regno == PT_USP)
addr = &task->thread.usp;
else if (regno < ARRAY_SIZE(regoff))
addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
else
return 0;
/* Need to take stkadj into account. */
if (regno == PT_SR || regno == PT_PC) {
long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
addr = (unsigned long *) ((unsigned long)addr + stkadj);
/* The sr is actually a 16 bit register. */
if (regno == PT_SR)
return *(unsigned short *)addr;
}
return *addr;
}
/*
* Write contents of register REGNO in task TASK.
*/
static inline int put_reg(struct task_struct *task, int regno,
unsigned long data)
{
unsigned long *addr;
if (regno == PT_USP)
addr = &task->thread.usp;
else if (regno < ARRAY_SIZE(regoff))
addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
else
return -1;
/* Need to take stkadj into account. */
if (regno == PT_SR || regno == PT_PC) {
long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
addr = (unsigned long *) ((unsigned long)addr + stkadj);
/* The sr is actually a 16 bit register. */
if (regno == PT_SR) {
*(unsigned short *)addr = data;
return 0;
}
}
*addr = data;
return 0;
}
/*
* Make sure the single step bit is not set.
*/
static inline void singlestep_disable(struct task_struct *child)
{
unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
put_reg(child, PT_SR, tmp);
clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
}
/*
* Called by kernel/ptrace.c when detaching..
*/
void ptrace_disable(struct task_struct *child)
{
singlestep_disable(child);
}
void user_enable_single_step(struct task_struct *child)
{
unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
put_reg(child, PT_SR, tmp | T1_BIT);
set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
}
#ifdef CONFIG_MMU
void user_enable_block_step(struct task_struct *child)
{
unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
put_reg(child, PT_SR, tmp | T0_BIT);
}
#endif
void user_disable_single_step(struct task_struct *child)
{
singlestep_disable(child);
}
long arch_ptrace(struct task_struct *child, long request,
unsigned long addr, unsigned long data)
{
unsigned long tmp;
int i, ret = 0;
int regno = addr >> 2; /* temporary hack. */
unsigned long __user *datap = (unsigned long __user *) data;
switch (request) {
/* read the word at location addr in the USER area. */
case PTRACE_PEEKUSR:
if (addr & 3)
goto out_eio;
if (regno >= 0 && regno < 19) {
tmp = get_reg(child, regno);
} else if (regno >= 21 && regno < 49) {
tmp = child->thread.fp[regno - 21];
/* Convert internal fpu reg representation
* into long double format
*/
if (FPU_IS_EMU && (regno < 45) && !(regno % 3))
tmp = ((tmp & 0xffff0000) << 15) |
((tmp & 0x0000ffff) << 16);
#ifndef CONFIG_MMU
} else if (regno == 49) {
tmp = child->mm->start_code;
} else if (regno == 50) {
tmp = child->mm->start_data;
} else if (regno == 51) {
tmp = child->mm->end_code;
#endif
} else
goto out_eio;
ret = put_user(tmp, datap);
break;
case PTRACE_POKEUSR:
/* write the word at location addr in the USER area */
if (addr & 3)
goto out_eio;
if (regno == PT_SR) {
data &= SR_MASK;
data |= get_reg(child, PT_SR) & ~SR_MASK;
}
if (regno >= 0 && regno < 19) {
if (put_reg(child, regno, data))
goto out_eio;
} else if (regno >= 21 && regno < 48) {
/* Convert long double format
* into internal fpu reg representation
*/
if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) {
data <<= 15;
data = (data & 0xffff0000) |
((data & 0x0000ffff) >> 1);
}
child->thread.fp[regno - 21] = data;
} else
goto out_eio;
break;
case PTRACE_GETREGS: /* Get all gp regs from the child. */
for (i = 0; i < 19; i++) {
tmp = get_reg(child, i);
ret = put_user(tmp, datap);
if (ret)
break;
datap++;
}
break;
case PTRACE_SETREGS: /* Set all gp regs in the child. */
for (i = 0; i < 19; i++) {
ret = get_user(tmp, datap);
if (ret)
break;
if (i == PT_SR) {
tmp &= SR_MASK;
tmp |= get_reg(child, PT_SR) & ~SR_MASK;
}
put_reg(child, i, tmp);
datap++;
}
break;
case PTRACE_GETFPREGS: /* Get the child FPU state. */
if (copy_to_user(datap, &child->thread.fp,
sizeof(struct user_m68kfp_struct)))
ret = -EFAULT;
break;
case PTRACE_SETFPREGS: /* Set the child FPU state. */
if (copy_from_user(&child->thread.fp, datap,
sizeof(struct user_m68kfp_struct)))
ret = -EFAULT;
break;
case PTRACE_GET_THREAD_AREA:
ret = put_user(task_thread_info(child)->tp_value, datap);
break;
default:
ret = ptrace_request(child, request, addr, data);
break;
}
return ret;
out_eio:
return -EIO;
}
asmlinkage void syscall_trace(void)
{
ptrace_report_syscall(0);
}
#if defined(CONFIG_COLDFIRE) || !defined(CONFIG_MMU)
asmlinkage int syscall_trace_enter(void)
{
int ret = 0;
if (test_thread_flag(TIF_SYSCALL_TRACE))
ret = ptrace_report_syscall_entry(task_pt_regs(current));
return ret;
}
asmlinkage void syscall_trace_leave(void)
{
if (test_thread_flag(TIF_SYSCALL_TRACE))
ptrace_report_syscall_exit(task_pt_regs(current), 0);
}
#endif /* CONFIG_COLDFIRE */
#if defined(CONFIG_BINFMT_ELF_FDPIC) && defined(CONFIG_ELF_CORE)
/*
* Currently the only thing that needs to use regsets for m68k is the
* coredump support of the elf_fdpic loader. Implement the minimum
* definitions required for that.
*/
static int m68k_regset_get(struct task_struct *target,
const struct user_regset *regset,
struct membuf to)
{
struct pt_regs *ptregs = task_pt_regs(target);
u32 uregs[ELF_NGREG];
ELF_CORE_COPY_REGS(uregs, ptregs);
return membuf_write(&to, uregs, sizeof(uregs));
}
enum m68k_regset {
REGSET_GPR,
#ifdef CONFIG_FPU
REGSET_FPU,
#endif
};
static const struct user_regset m68k_user_regsets[] = {
[REGSET_GPR] = {
.core_note_type = NT_PRSTATUS,
.n = ELF_NGREG,
.size = sizeof(u32),
.align = sizeof(u16),
.regset_get = m68k_regset_get,
},
#ifdef CONFIG_FPU
[REGSET_FPU] = {
.core_note_type = NT_PRFPREG,
.n = sizeof(struct user_m68kfp_struct) / sizeof(u32),
.size = sizeof(u32),
.align = sizeof(u32),
}
#endif /* CONFIG_FPU */
};
static const struct user_regset_view user_m68k_view = {
.name = "m68k",
.e_machine = EM_68K,
.ei_osabi = ELF_OSABI,
.regsets = m68k_user_regsets,
.n = ARRAY_SIZE(m68k_user_regsets)
};
const struct user_regset_view *task_user_regset_view(struct task_struct *task)
{
return &user_m68k_view;
}
#endif /* CONFIG_BINFMT_ELF_FDPIC && CONFIG_ELF_CORE */