/*
* ptrace cpu depend helper functions
*
* Copyright 2003, 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
*
* 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/linkage.h>
#include <linux/sched/signal.h>
#include <asm/ptrace.h>
#define BREAKINST 0x5730 /* trapa #3 */
/* disable singlestep */
void user_disable_single_step(struct task_struct *child)
{
if ((long)child->thread.breakinfo.addr != -1L) {
*(child->thread.breakinfo.addr) = child->thread.breakinfo.inst;
child->thread.breakinfo.addr = (unsigned short *)-1L;
}
}
/* calculate next pc */
enum jump_type {none, /* normal instruction */
jabs, /* absolute address jump */
ind, /* indirect address jump */
ret, /* return to subrutine */
reg, /* register indexed jump */
relb, /* pc relative jump (byte offset) */
relw, /* pc relative jump (word offset) */
};
/* opcode decode table define
ptn: opcode pattern
msk: opcode bitmask
len: instruction length (<0 next table index)
jmp: jump operation mode */
struct optable {
unsigned char bitpattern;
unsigned char bitmask;
signed char length;
signed char type;
} __packed __aligned(1);
#define OPTABLE(ptn, msk, len, jmp) \
{ \
.bitpattern = ptn, \
.bitmask = msk, \
.length = len, \
.type = jmp, \
}
static const struct optable optable_0[] = {
OPTABLE(0x00, 0xff, 1, none), /* 0x00 */
OPTABLE(0x01, 0xff, -1, none), /* 0x01 */
OPTABLE(0x02, 0xfe, 1, none), /* 0x02-0x03 */
OPTABLE(0x04, 0xee, 1, none), /* 0x04-0x05/0x14-0x15 */
OPTABLE(0x06, 0xfe, 1, none), /* 0x06-0x07 */
OPTABLE(0x08, 0xea, 1, none), /* 0x08-0x09/0x0c-0x0d/0x18-0x19/0x1c-0x1d */
OPTABLE(0x0a, 0xee, 1, none), /* 0x0a-0x0b/0x1a-0x1b */
OPTABLE(0x0e, 0xee, 1, none), /* 0x0e-0x0f/0x1e-0x1f */
OPTABLE(0x10, 0xfc, 1, none), /* 0x10-0x13 */
OPTABLE(0x16, 0xfe, 1, none), /* 0x16-0x17 */
OPTABLE(0x20, 0xe0, 1, none), /* 0x20-0x3f */
OPTABLE(0x40, 0xf0, 1, relb), /* 0x40-0x4f */
OPTABLE(0x50, 0xfc, 1, none), /* 0x50-0x53 */
OPTABLE(0x54, 0xfd, 1, ret), /* 0x54/0x56 */
OPTABLE(0x55, 0xff, 1, relb), /* 0x55 */
OPTABLE(0x57, 0xff, 1, none), /* 0x57 */
OPTABLE(0x58, 0xfb, 2, relw), /* 0x58/0x5c */
OPTABLE(0x59, 0xfb, 1, reg), /* 0x59/0x5b */
OPTABLE(0x5a, 0xfb, 2, jabs), /* 0x5a/0x5e */
OPTABLE(0x5b, 0xfb, 2, ind), /* 0x5b/0x5f */
OPTABLE(0x60, 0xe8, 1, none), /* 0x60-0x67/0x70-0x77 */
OPTABLE(0x68, 0xfa, 1, none), /* 0x68-0x69/0x6c-0x6d */
OPTABLE(0x6a, 0xfe, -2, none), /* 0x6a-0x6b */
OPTABLE(0x6e, 0xfe, 2, none), /* 0x6e-0x6f */
OPTABLE(0x78, 0xff, 4, none), /* 0x78 */
OPTABLE(0x79, 0xff, 2, none), /* 0x79 */
OPTABLE(0x7a, 0xff, 3, none), /* 0x7a */
OPTABLE(0x7b, 0xff, 2, none), /* 0x7b */
OPTABLE(0x7c, 0xfc, 2, none), /* 0x7c-0x7f */
OPTABLE(0x80, 0x80, 1, none), /* 0x80-0xff */
};
static const struct optable optable_1[] = {
OPTABLE(0x00, 0xff, -3, none), /* 0x0100 */
OPTABLE(0x40, 0xf0, -3, none), /* 0x0140-0x14f */
OPTABLE(0x80, 0xf0, 1, none), /* 0x0180-0x018f */
OPTABLE(0xc0, 0xc0, 2, none), /* 0x01c0-0x01ff */
};
static const struct optable optable_2[] = {
OPTABLE(0x00, 0x20, 2, none), /* 0x6a0?/0x6a8?/0x6b0?/0x6b8? */
OPTABLE(0x20, 0x20, 3, none), /* 0x6a2?/0x6aa?/0x6b2?/0x6ba? */
};
static const struct optable optable_3[] = {
OPTABLE(0x69, 0xfb, 2, none), /* 0x010069/0x01006d/014069/0x01406d */
OPTABLE(0x6b, 0xff, -4, none), /* 0x01006b/0x01406b */
OPTABLE(0x6f, 0xff, 3, none), /* 0x01006f/0x01406f */
OPTABLE(0x78, 0xff, 5, none), /* 0x010078/0x014078 */
};
static const struct optable optable_4[] = {
/* 0x0100690?/0x01006d0?/0140690?/0x01406d0?/
0x0100698?/0x01006d8?/0140698?/0x01406d8? */
OPTABLE(0x00, 0x78, 3, none),
/* 0x0100692?/0x01006d2?/0140692?/0x01406d2?/
0x010069a?/0x01006da?/014069a?/0x01406da? */
OPTABLE(0x20, 0x78, 4, none),
};
static const struct optables_list {
const struct optable *ptr;
int size;
} optables[] = {
#define OPTABLES(no) \
{ \
.ptr = optable_##no, \
.size = sizeof(optable_##no) / sizeof(struct optable), \
}
OPTABLES(0),
OPTABLES(1),
OPTABLES(2),
OPTABLES(3),
OPTABLES(4),
};
const unsigned char condmask[] = {
0x00, 0x40, 0x01, 0x04, 0x02, 0x08, 0x10, 0x20
};
static int isbranch(struct task_struct *task, int reson)
{
unsigned char cond = h8300_get_reg(task, PT_CCR);
/* encode complex conditions */
/* B4: N^V
B5: Z|(N^V)
B6: C|Z */
__asm__("bld #3,%w0\n\t"
"bxor #1,%w0\n\t"
"bst #4,%w0\n\t"
"bor #2,%w0\n\t"
"bst #5,%w0\n\t"
"bld #2,%w0\n\t"
"bor #0,%w0\n\t"
"bst #6,%w0\n\t"
: "=&r"(cond) : "0"(cond) : "cc");
cond &= condmask[reson >> 1];
if (!(reson & 1))
return cond == 0;
else
return cond != 0;
}
static unsigned short *decode(struct task_struct *child,
const struct optable *op,
char *fetch_p, unsigned short *pc,
unsigned char inst)
{
unsigned long addr;
unsigned long *sp;
int regno;
switch (op->type) {
case none:
return (unsigned short *)pc + op->length;
case jabs:
addr = *(unsigned long *)pc;
return (unsigned short *)(addr & 0x00ffffff);
case ind:
addr = *pc & 0xff;
return (unsigned short *)(*(unsigned long *)addr);
case ret:
sp = (unsigned long *)h8300_get_reg(child, PT_USP);
/* user stack frames
| er0 | temporary saved
+--------+
| exp | exception stack frames
+--------+
| ret pc | userspace return address
*/
return (unsigned short *)(*(sp+2) & 0x00ffffff);
case reg:
regno = (*pc >> 4) & 0x07;
if (regno == 0)
addr = h8300_get_reg(child, PT_ER0);
else
addr = h8300_get_reg(child, regno-1 + PT_ER1);
return (unsigned short *)addr;
case relb:
if (inst == 0x55 || isbranch(child, inst & 0x0f))
pc = (unsigned short *)((unsigned long)pc +
((signed char)(*fetch_p)));
return pc+1; /* skip myself */
case relw:
if (inst == 0x5c || isbranch(child, (*fetch_p & 0xf0) >> 4))
pc = (unsigned short *)((unsigned long)pc +
((signed short)(*(pc+1))));
return pc+2; /* skip myself */
default:
return NULL;
}
}
static unsigned short *nextpc(struct task_struct *child, unsigned short *pc)
{
const struct optable *op;
unsigned char *fetch_p;
int op_len;
unsigned char inst;
op = optables[0].ptr;
op_len = optables[0].size;
fetch_p = (unsigned char *)pc;
inst = *fetch_p++;
do {
if ((inst & op->bitmask) == op->bitpattern) {
if (op->length < 0) {
op = optables[-op->length].ptr;
op_len = optables[-op->length].size + 1;
inst = *fetch_p++;
} else
return decode(child, op, fetch_p, pc, inst);
} else
op++;
} while (--op_len > 0);
return NULL;
}
/* Set breakpoint(s) to simulate a single step from the current PC. */
void user_enable_single_step(struct task_struct *child)
{
unsigned short *next;
next = nextpc(child, (unsigned short *)h8300_get_reg(child, PT_PC));
child->thread.breakinfo.addr = next;
child->thread.breakinfo.inst = *next;
*next = BREAKINST;
}
asmlinkage void trace_trap(unsigned long bp)
{
if ((unsigned long)current->thread.breakinfo.addr == bp) {
user_disable_single_step(current);
force_sig(SIGTRAP);
} else
force_sig(SIGILL);
}
