1/* 2 * ptrace cpu depend helper functions 3 * 4 * Copyright 2003, 2015 Yoshinori Sato <ysato@users.sourceforge.jp> 5 * 6 * This file is subject to the terms and conditions of the GNU General 7 * Public License. See the file COPYING in the main directory of 8 * this archive for more details. 9 */ 10 11#include <linux/linkage.h> 12#include <linux/sched.h> 13#include <asm/ptrace.h> 14 15#define BREAKINST 0x5730 /* trapa #3 */ 16 17/* disable singlestep */ 18void user_disable_single_step(struct task_struct *child) 19{ 20 if ((long)child->thread.breakinfo.addr != -1L) { 21 *(child->thread.breakinfo.addr) = child->thread.breakinfo.inst; 22 child->thread.breakinfo.addr = (unsigned short *)-1L; 23 } 24} 25 26/* calculate next pc */ 27enum jump_type {none, /* normal instruction */ 28 jabs, /* absolute address jump */ 29 ind, /* indirect address jump */ 30 ret, /* return to subrutine */ 31 reg, /* register indexed jump */ 32 relb, /* pc relative jump (byte offset) */ 33 relw, /* pc relative jump (word offset) */ 34 }; 35 36/* opcode decode table define 37 ptn: opcode pattern 38 msk: opcode bitmask 39 len: instruction length (<0 next table index) 40 jmp: jump operation mode */ 41struct optable { 42 unsigned char bitpattern; 43 unsigned char bitmask; 44 signed char length; 45 signed char type; 46} __packed __aligned(1); 47 48#define OPTABLE(ptn, msk, len, jmp) \ 49 { \ 50 .bitpattern = ptn, \ 51 .bitmask = msk, \ 52 .length = len, \ 53 .type = jmp, \ 54 } 55 56static const struct optable optable_0[] = { 57 OPTABLE(0x00, 0xff, 1, none), /* 0x00 */ 58 OPTABLE(0x01, 0xff, -1, none), /* 0x01 */ 59 OPTABLE(0x02, 0xfe, 1, none), /* 0x02-0x03 */ 60 OPTABLE(0x04, 0xee, 1, none), /* 0x04-0x05/0x14-0x15 */ 61 OPTABLE(0x06, 0xfe, 1, none), /* 0x06-0x07 */ 62 OPTABLE(0x08, 0xea, 1, none), /* 0x08-0x09/0x0c-0x0d/0x18-0x19/0x1c-0x1d */ 63 OPTABLE(0x0a, 0xee, 1, none), /* 0x0a-0x0b/0x1a-0x1b */ 64 OPTABLE(0x0e, 0xee, 1, none), /* 0x0e-0x0f/0x1e-0x1f */ 65 OPTABLE(0x10, 0xfc, 1, none), /* 0x10-0x13 */ 66 OPTABLE(0x16, 0xfe, 1, none), /* 0x16-0x17 */ 67 OPTABLE(0x20, 0xe0, 1, none), /* 0x20-0x3f */ 68 OPTABLE(0x40, 0xf0, 1, relb), /* 0x40-0x4f */ 69 OPTABLE(0x50, 0xfc, 1, none), /* 0x50-0x53 */ 70 OPTABLE(0x54, 0xfd, 1, ret), /* 0x54/0x56 */ 71 OPTABLE(0x55, 0xff, 1, relb), /* 0x55 */ 72 OPTABLE(0x57, 0xff, 1, none), /* 0x57 */ 73 OPTABLE(0x58, 0xfb, 2, relw), /* 0x58/0x5c */ 74 OPTABLE(0x59, 0xfb, 1, reg), /* 0x59/0x5b */ 75 OPTABLE(0x5a, 0xfb, 2, jabs), /* 0x5a/0x5e */ 76 OPTABLE(0x5b, 0xfb, 2, ind), /* 0x5b/0x5f */ 77 OPTABLE(0x60, 0xe8, 1, none), /* 0x60-0x67/0x70-0x77 */ 78 OPTABLE(0x68, 0xfa, 1, none), /* 0x68-0x69/0x6c-0x6d */ 79 OPTABLE(0x6a, 0xfe, -2, none), /* 0x6a-0x6b */ 80 OPTABLE(0x6e, 0xfe, 2, none), /* 0x6e-0x6f */ 81 OPTABLE(0x78, 0xff, 4, none), /* 0x78 */ 82 OPTABLE(0x79, 0xff, 2, none), /* 0x79 */ 83 OPTABLE(0x7a, 0xff, 3, none), /* 0x7a */ 84 OPTABLE(0x7b, 0xff, 2, none), /* 0x7b */ 85 OPTABLE(0x7c, 0xfc, 2, none), /* 0x7c-0x7f */ 86 OPTABLE(0x80, 0x80, 1, none), /* 0x80-0xff */ 87}; 88 89static const struct optable optable_1[] = { 90 OPTABLE(0x00, 0xff, -3, none), /* 0x0100 */ 91 OPTABLE(0x40, 0xf0, -3, none), /* 0x0140-0x14f */ 92 OPTABLE(0x80, 0xf0, 1, none), /* 0x0180-0x018f */ 93 OPTABLE(0xc0, 0xc0, 2, none), /* 0x01c0-0x01ff */ 94}; 95 96static const struct optable optable_2[] = { 97 OPTABLE(0x00, 0x20, 2, none), /* 0x6a0?/0x6a8?/0x6b0?/0x6b8? */ 98 OPTABLE(0x20, 0x20, 3, none), /* 0x6a2?/0x6aa?/0x6b2?/0x6ba? */ 99}; 100 101static const struct optable optable_3[] = { 102 OPTABLE(0x69, 0xfb, 2, none), /* 0x010069/0x01006d/014069/0x01406d */ 103 OPTABLE(0x6b, 0xff, -4, none), /* 0x01006b/0x01406b */ 104 OPTABLE(0x6f, 0xff, 3, none), /* 0x01006f/0x01406f */ 105 OPTABLE(0x78, 0xff, 5, none), /* 0x010078/0x014078 */ 106}; 107 108static const struct optable optable_4[] = { 109/* 0x0100690?/0x01006d0?/0140690?/0x01406d0?/ 110 0x0100698?/0x01006d8?/0140698?/0x01406d8? */ 111 OPTABLE(0x00, 0x78, 3, none), 112/* 0x0100692?/0x01006d2?/0140692?/0x01406d2?/ 113 0x010069a?/0x01006da?/014069a?/0x01406da? */ 114 OPTABLE(0x20, 0x78, 4, none), 115}; 116 117static const struct optables_list { 118 const struct optable *ptr; 119 int size; 120} optables[] = { 121#define OPTABLES(no) \ 122 { \ 123 .ptr = optable_##no, \ 124 .size = sizeof(optable_##no) / sizeof(struct optable), \ 125 } 126 OPTABLES(0), 127 OPTABLES(1), 128 OPTABLES(2), 129 OPTABLES(3), 130 OPTABLES(4), 131 132}; 133 134const unsigned char condmask[] = { 135 0x00, 0x40, 0x01, 0x04, 0x02, 0x08, 0x10, 0x20 136}; 137 138static int isbranch(struct task_struct *task, int reson) 139{ 140 unsigned char cond = h8300_get_reg(task, PT_CCR); 141 142 /* encode complex conditions */ 143 /* B4: N^V 144 B5: Z|(N^V) 145 B6: C|Z */ 146 __asm__("bld #3,%w0\n\t" 147 "bxor #1,%w0\n\t" 148 "bst #4,%w0\n\t" 149 "bor #2,%w0\n\t" 150 "bst #5,%w0\n\t" 151 "bld #2,%w0\n\t" 152 "bor #0,%w0\n\t" 153 "bst #6,%w0\n\t" 154 : "=&r"(cond) : "0"(cond) : "cc"); 155 cond &= condmask[reson >> 1]; 156 if (!(reson & 1)) 157 return cond == 0; 158 else 159 return cond != 0; 160} 161 162static unsigned short *decode(struct task_struct *child, 163 const struct optable *op, 164 char *fetch_p, unsigned short *pc, 165 unsigned char inst) 166{ 167 unsigned long addr; 168 unsigned long *sp; 169 int regno; 170 171 switch (op->type) { 172 case none: 173 return (unsigned short *)pc + op->length; 174 case jabs: 175 addr = *(unsigned long *)pc; 176 return (unsigned short *)(addr & 0x00ffffff); 177 case ind: 178 addr = *pc & 0xff; 179 return (unsigned short *)(*(unsigned long *)addr); 180 case ret: 181 sp = (unsigned long *)h8300_get_reg(child, PT_USP); 182 /* user stack frames 183 | er0 | temporary saved 184 +--------+ 185 | exp | exception stack frames 186 +--------+ 187 | ret pc | userspace return address 188 */ 189 return (unsigned short *)(*(sp+2) & 0x00ffffff); 190 case reg: 191 regno = (*pc >> 4) & 0x07; 192 if (regno == 0) 193 addr = h8300_get_reg(child, PT_ER0); 194 else 195 addr = h8300_get_reg(child, regno-1 + PT_ER1); 196 return (unsigned short *)addr; 197 case relb: 198 if (inst == 0x55 || isbranch(child, inst & 0x0f)) 199 pc = (unsigned short *)((unsigned long)pc + 200 ((signed char)(*fetch_p))); 201 return pc+1; /* skip myself */ 202 case relw: 203 if (inst == 0x5c || isbranch(child, (*fetch_p & 0xf0) >> 4)) 204 pc = (unsigned short *)((unsigned long)pc + 205 ((signed short)(*(pc+1)))); 206 return pc+2; /* skip myself */ 207 default: 208 return NULL; 209 } 210} 211 212static unsigned short *nextpc(struct task_struct *child, unsigned short *pc) 213{ 214 const struct optable *op; 215 unsigned char *fetch_p; 216 int op_len; 217 unsigned char inst; 218 219 op = optables[0].ptr; 220 op_len = optables[0].size; 221 fetch_p = (unsigned char *)pc; 222 inst = *fetch_p++; 223 do { 224 if ((inst & op->bitmask) == op->bitpattern) { 225 if (op->length < 0) { 226 op = optables[-op->length].ptr; 227 op_len = optables[-op->length].size + 1; 228 inst = *fetch_p++; 229 } else 230 return decode(child, op, fetch_p, pc, inst); 231 } else 232 op++; 233 } while (--op_len > 0); 234 return NULL; 235} 236 237/* Set breakpoint(s) to simulate a single step from the current PC. */ 238 239void user_enable_single_step(struct task_struct *child) 240{ 241 unsigned short *next; 242 243 next = nextpc(child, (unsigned short *)h8300_get_reg(child, PT_PC)); 244 child->thread.breakinfo.addr = next; 245 child->thread.breakinfo.inst = *next; 246 *next = BREAKINST; 247} 248 249asmlinkage void trace_trap(unsigned long bp) 250{ 251 if ((unsigned long)current->thread.breakinfo.addr == bp) { 252 user_disable_single_step(current); 253 force_sig(SIGTRAP, current); 254 } else 255 force_sig(SIGILL, current); 256} 257