uprobe/arch/asm-arm/swap_uprobes.c

   1 #include <dbi_kprobes.h>
   2 #include <asm/dbi_kprobes.h>
   3 #include <asm/traps.h>
   4
   5 // FIXME:
   6 #include <dbi_kdebug.h>
   7 extern struct hlist_head uprobe_insn_pages;
   8 kprobe_opcode_t *get_insn_slot(struct task_struct *task, struct hlist_head *page_list, int atomic);
   9 int arch_check_insn_arm(struct arch_specific_insn *ainsn);
  10 int prep_pc_dep_insn_execbuf(kprobe_opcode_t *insns, kprobe_opcode_t insn, int uregs);
  11 void free_insn_slot(struct hlist_head *page_list, struct task_struct *task, kprobe_opcode_t *slot);
  12 void pc_dep_insn_execbuf(void);
  13 void gen_insn_execbuf(void);
  14 void gen_insn_execbuf_thumb(void);
  15 void pc_dep_insn_execbuf_thumb(void);
  16 int kprobe_trap_handler(struct pt_regs *regs, unsigned int instr);
  17
  18
  19 #define sign_extend(x, signbit) ((x) | (0 - ((x) & (1 << (signbit)))))
  20 #define branch_displacement(insn) sign_extend(((insn) & 0xffffff) << 2, 25)
  21
  22 static kprobe_opcode_t get_addr_b(kprobe_opcode_t insn, kprobe_opcode_t *addr)
  23 {
  24         // real position less then PC by 8
  25         return (kprobe_opcode_t)((long)addr + 8 + branch_displacement(insn));
  26 }
  27
  28 /* is instruction Thumb2 and NOT a branch, etc... */
  29 static int is_thumb2(kprobe_opcode_t insn)
  30 {
  31         return ((insn & 0xf800) == 0xe800 ||
  32                 (insn & 0xf800) == 0xf000 ||
  33                 (insn & 0xf800) == 0xf800);
  34 }
  35
  36 static int arch_copy_trampoline_arm_uprobe(struct kprobe *p, struct task_struct *task, int atomic)
  37 {
  38         kprobe_opcode_t insns[UPROBES_TRAMP_LEN];
  39         int uregs, pc_dep;
  40         kprobe_opcode_t insn[MAX_INSN_SIZE];
  41         struct arch_specific_insn ainsn;
  42
  43         p->safe_arm = -1;
  44         if ((unsigned long)p->addr & 0x01) {
  45                 printk("Error in %s at %d: attempt to register kprobe at an unaligned address\n", __FILE__, __LINE__);
  46                 return -EINVAL;
  47         }
  48
  49         insn[0] = p->opcode;
  50         ainsn.insn_arm = insn;
  51         if (!arch_check_insn_arm(&ainsn)) {
  52                 p->safe_arm = 0;
  53         }
  54
  55         uregs = pc_dep = 0;
  56         // Rn, Rm ,Rd
  57         if (ARM_INSN_MATCH(DPIS, insn[0]) || ARM_INSN_MATCH(LRO, insn[0]) ||
  58             ARM_INSN_MATCH(SRO, insn[0])) {
  59                 uregs = 0xb;
  60                 if ((ARM_INSN_REG_RN(insn[0]) == 15) || (ARM_INSN_REG_RM(insn[0]) == 15) ||
  61                     (ARM_INSN_MATCH(SRO, insn[0]) && (ARM_INSN_REG_RD(insn[0]) == 15))) {
  62                         DBPRINTF("Unboostable insn %lx, DPIS/LRO/SRO\n", insn[0]);
  63                         pc_dep = 1;
  64                 }
  65
  66         // Rn ,Rd
  67         } else if (ARM_INSN_MATCH(DPI, insn[0]) || ARM_INSN_MATCH(LIO, insn[0]) ||
  68                    ARM_INSN_MATCH (SIO, insn[0])) {
  69                 uregs = 0x3;
  70                 if ((ARM_INSN_REG_RN(insn[0]) == 15) || (ARM_INSN_MATCH(SIO, insn[0]) &&
  71                     (ARM_INSN_REG_RD(insn[0]) == 15))) {
  72                         pc_dep = 1;
  73                         DBPRINTF("Unboostable insn %lx/%p, DPI/LIO/SIO\n", insn[0], p);
  74                 }
  75
  76         // Rn, Rm, Rs
  77         } else if (ARM_INSN_MATCH(DPRS, insn[0])) {
  78                 uregs = 0xd;
  79                 if ((ARM_INSN_REG_RN(insn[0]) == 15) || (ARM_INSN_REG_RM(insn[0]) == 15) ||
  80                     (ARM_INSN_REG_RS(insn[0]) == 15)) {
  81                         pc_dep = 1;
  82                         DBPRINTF("Unboostable insn %lx, DPRS\n", insn[0]);
  83                 }
  84
  85         // register list
  86         } else if (ARM_INSN_MATCH(SM, insn[0])) {
  87                 uregs = 0x10;
  88                 if (ARM_INSN_REG_MR (insn[0], 15))
  89                 {
  90                         DBPRINTF ("Unboostable insn %lx, SM\n", insn[0]);
  91                         pc_dep = 1;
  92                 }
  93         }
  94
  95         // check instructions that can write result to SP andu uses PC
  96         if (pc_dep  && (ARM_INSN_REG_RD (ainsn.insn_arm[0]) == 13)) {
  97                 printk("Error in %s at %d: instruction check failed (arm)\n", __FILE__, __LINE__);
  98                 p->safe_arm = -1;
  99                 // TODO: move free to later phase
 100                 //free_insn_slot (&uprobe_insn_pages, task, p->ainsn.insn_arm, 0);
 101                 //ret = -EFAULT;
 102         }
 103
 104         if (unlikely(uregs && pc_dep)) {
 105                 memcpy(insns, pc_dep_insn_execbuf, sizeof(insns));
 106                 if (prep_pc_dep_insn_execbuf(insns, insn[0], uregs) != 0) {
 107                         printk("Error in %s at %d: failed to prepare exec buffer for insn %lx!",
 108                                __FILE__, __LINE__, insn[0]);
 109                         p->safe_arm = -1;
 110                         // TODO: move free to later phase
 111                         //free_insn_slot (&uprobe_insn_pages, task, p->ainsn.insn_arm, 0);
 112                         //return -EINVAL;
 113                 }
 114
 115                 insns[6] = (kprobe_opcode_t) (p->addr + 2);
 116         } else {
 117                 memcpy(insns, gen_insn_execbuf, sizeof(insns));
 118                 insns[UPROBES_TRAMP_INSN_IDX] = insn[0];
 119         }
 120
 121         insns[UPROBES_TRAMP_RET_BREAK_IDX] = BREAKPOINT_INSTRUCTION;
 122         insns[7] = (kprobe_opcode_t) (p->addr + 1);
 123
 124         // B
 125         if(ARM_INSN_MATCH(B, ainsn.insn_arm[0])) {
 126                 memcpy(insns, pc_dep_insn_execbuf, sizeof(insns));
 127                 insns[UPROBES_TRAMP_RET_BREAK_IDX] = BREAKPOINT_INSTRUCTION;
 128                 insns[6] = (kprobe_opcode_t)(p->addr + 2);
 129                 insns[7] = get_addr_b(p->opcode, p->addr);
 130         }
 131
 132         DBPRINTF("arch_prepare_uprobe: to %p - %lx %lx %lx %lx %lx %lx %lx %lx %lx",
 133                  p->ainsn.insn_arm, insns[0], insns[1], insns[2], insns[3], insns[4],
 134                  insns[5], insns[6], insns[7], insns[8]);
 135         if (!write_proc_vm_atomic(task, (unsigned long)p->ainsn.insn_arm, insns, sizeof(insns))) {
 136                 panic("failed to write memory %p!\n", p->ainsn.insn_arm);
 137                 // Mr_Nobody: we have to panic, really??...
 138                 //free_insn_slot (&uprobe_insn_pages, task, p->ainsn.insn_arm, 0);
 139                 //return -EINVAL;
 140         }
 141
 142         return 0;
 143 }
 144
 145 static int arch_check_insn_thumb(struct arch_specific_insn *ainsn)
 146 {
 147         int ret = 0;
 148
 149         // check instructions that can change PC
 150         if (THUMB_INSN_MATCH(UNDEF, ainsn->insn_thumb[0]) ||
 151             THUMB_INSN_MATCH(SWI, ainsn->insn_thumb[0]) ||
 152             THUMB_INSN_MATCH(BREAK, ainsn->insn_thumb[0]) ||
 153             THUMB2_INSN_MATCH(BL, ainsn->insn_thumb[0]) ||
 154             THUMB_INSN_MATCH(B1, ainsn->insn_thumb[0]) ||
 155             THUMB_INSN_MATCH(B2, ainsn->insn_thumb[0]) ||
 156             THUMB_INSN_MATCH(CBZ, ainsn->insn_thumb[0]) ||
 157             THUMB2_INSN_MATCH(B1, ainsn->insn_thumb[0]) ||
 158             THUMB2_INSN_MATCH(B2, ainsn->insn_thumb[0]) ||
 159             THUMB2_INSN_MATCH(BLX1, ainsn->insn_thumb[0]) ||
 160             THUMB_INSN_MATCH(BLX2, ainsn->insn_thumb[0]) ||
 161             THUMB_INSN_MATCH(BX, ainsn->insn_thumb[0]) ||
 162             THUMB2_INSN_MATCH(BXJ, ainsn->insn_thumb[0]) ||
 163             (THUMB2_INSN_MATCH(ADR, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 164             (THUMB2_INSN_MATCH(LDRW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RT(ainsn->insn_thumb[0]) == 15) ||
 165             (THUMB2_INSN_MATCH(LDRW1, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RT(ainsn->insn_thumb[0]) == 15) ||
 166             (THUMB2_INSN_MATCH(LDRHW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RT(ainsn->insn_thumb[0]) == 15) ||
 167             (THUMB2_INSN_MATCH(LDRHW1, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RT(ainsn->insn_thumb[0]) == 15) ||
 168             (THUMB2_INSN_MATCH(LDRWL, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RT(ainsn->insn_thumb[0]) == 15) ||
 169             THUMB2_INSN_MATCH(LDMIA, ainsn->insn_thumb[0]) ||
 170             THUMB2_INSN_MATCH(LDMDB, ainsn->insn_thumb[0]) ||
 171             (THUMB2_INSN_MATCH(DP, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 172             (THUMB2_INSN_MATCH(RSBW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 173             (THUMB2_INSN_MATCH(RORW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 174             (THUMB2_INSN_MATCH(ROR, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 175             (THUMB2_INSN_MATCH(LSLW1, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 176             (THUMB2_INSN_MATCH(LSLW2, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 177             (THUMB2_INSN_MATCH(LSRW1, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 178             (THUMB2_INSN_MATCH(LSRW2, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RD(ainsn->insn_thumb[0]) == 15) ||
 179             /* skip PC, #-imm12 -> SP, #-imm8 and Tegra-hanging instructions */
 180             (THUMB2_INSN_MATCH(STRW1, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 181             (THUMB2_INSN_MATCH(STRBW1, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 182             (THUMB2_INSN_MATCH(STRHW1, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 183             (THUMB2_INSN_MATCH(STRW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 184             (THUMB2_INSN_MATCH(STRHW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 185             (THUMB2_INSN_MATCH(LDRW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 186             (THUMB2_INSN_MATCH(LDRBW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 187             (THUMB2_INSN_MATCH(LDRHW, ainsn->insn_thumb[0]) && THUMB2_INSN_REG_RN(ainsn->insn_thumb[0]) == 15) ||
 188             /* skip STRDx/LDRDx Rt, Rt2, [Rd, ...] */
 189             (THUMB2_INSN_MATCH(LDRD, ainsn->insn_thumb[0]) || THUMB2_INSN_MATCH(LDRD1, ainsn->insn_thumb[0]) || THUMB2_INSN_MATCH(STRD, ainsn->insn_thumb[0])) ) {
 190                 DBPRINTF("Bad insn arch_check_insn_thumb: %lx\n", ainsn->insn_thumb[0]);
 191                 ret = -EFAULT;
 192         }
 193
 194         return ret;
 195 }
 196
 197 static int prep_pc_dep_insn_execbuf_thumb(kprobe_opcode_t * insns, kprobe_opcode_t insn, int uregs)
 198 {
 199         unsigned char mreg = 0;
 200         unsigned char reg = 0;
 201
 202         if (THUMB_INSN_MATCH(APC, insn) || THUMB_INSN_MATCH(LRO3, insn)) {
 203                 reg = ((insn & 0xffff) & uregs) >> 8;
 204         } else {
 205                 if (THUMB_INSN_MATCH(MOV3, insn)) {
 206                         if (((((unsigned char) insn) & 0xff) >> 3) == 15) {
 207                                 reg = (insn & 0xffff) & uregs;
 208                         } else {
 209                                 return 0;
 210                         }
 211                 } else {
 212                         if (THUMB2_INSN_MATCH(ADR, insn)) {
 213                                 reg = ((insn >> 16) & uregs) >> 8;
 214                                 if (reg == 15) {
 215                                         return 0;
 216                                 }
 217                         } else {
 218                                 if (THUMB2_INSN_MATCH(LDRW, insn) || THUMB2_INSN_MATCH(LDRW1, insn) ||
 219                                     THUMB2_INSN_MATCH(LDRHW, insn) || THUMB2_INSN_MATCH(LDRHW1, insn) ||
 220                                     THUMB2_INSN_MATCH(LDRWL, insn)) {
 221                                         reg = ((insn >> 16) & uregs) >> 12;
 222                                         if (reg == 15) {
 223                                                 return 0;
 224                                         }
 225                                 } else {
 226                                         // LDRB.W PC, [PC, #immed] => PLD [PC, #immed], so Rt == PC is skipped
 227                                         if (THUMB2_INSN_MATCH(LDRBW, insn) || THUMB2_INSN_MATCH(LDRBW1, insn) ||
 228                                             THUMB2_INSN_MATCH(LDREX, insn)) {
 229                                                 reg = ((insn >> 16) & uregs) >> 12;
 230                                         } else {
 231                                                 if (THUMB2_INSN_MATCH(DP, insn)) {
 232                                                         reg = ((insn >> 16) & uregs) >> 12;
 233                                                         if (reg == 15) {
 234                                                                 return 0;
 235                                                         }
 236                                                 } else {
 237                                                         if (THUMB2_INSN_MATCH(RSBW, insn)) {
 238                                                                 reg = ((insn >> 12) & uregs) >> 8;
 239                                                                 if (reg == 15){
 240                                                                         return 0;
 241                                                                 }
 242                                                         } else {
 243                                                                 if (THUMB2_INSN_MATCH(RORW, insn)) {
 244                                                                         reg = ((insn >> 12) & uregs) >> 8;
 245                                                                         if (reg == 15) {
 246                                                                                 return 0;
 247                                                                         }
 248                                                                 } else {
 249                                                                         if (THUMB2_INSN_MATCH(ROR, insn) || THUMB2_INSN_MATCH(LSLW1, insn) ||
 250                                                                             THUMB2_INSN_MATCH(LSLW2, insn) || THUMB2_INSN_MATCH(LSRW1, insn) ||
 251                                                                             THUMB2_INSN_MATCH(LSRW2, insn)) {
 252                                                                                 reg = ((insn >> 12) & uregs) >> 8;
 253                                                                                 if (reg == 15) {
 254                                                                                         return 0;
 255                                                                                 }
 256                                                                         } else {
 257                                                                                 if (THUMB2_INSN_MATCH(TEQ1, insn) || THUMB2_INSN_MATCH(TST1, insn)) {
 258                                                                                         reg = 15;
 259                                                                                 } else {
 260                                                                                         if (THUMB2_INSN_MATCH(TEQ2, insn) || THUMB2_INSN_MATCH(TST2, insn)) {
 261                                                                                                 reg = THUMB2_INSN_REG_RM(insn);
 262                                                                                         }
 263                                                                                 }
 264                                                                         }
 265                                                                 }
 266                                                         }
 267                                                 }
 268                                         }
 269                                 }
 270                         }
 271                 }
 272         }
 273
 274         if ((THUMB2_INSN_MATCH(STRW, insn) || THUMB2_INSN_MATCH(STRBW, insn) ||
 275              THUMB2_INSN_MATCH(STRD, insn) || THUMB2_INSN_MATCH(STRHT, insn) ||
 276              THUMB2_INSN_MATCH(STRT, insn) || THUMB2_INSN_MATCH(STRHW1, insn) ||
 277              THUMB2_INSN_MATCH(STRHW, insn)) && THUMB2_INSN_REG_RT(insn) == 15) {
 278                 reg = THUMB2_INSN_REG_RT(insn);
 279         }
 280
 281         if (reg == 6 || reg == 7) {
 282                 *((unsigned short*)insns + 0) = (*((unsigned short*)insns + 0) & 0x00ff) | ((1 << mreg) | (1 << (mreg + 1)));
 283                 *((unsigned short*)insns + 1) = (*((unsigned short*)insns + 1) & 0xf8ff) | (mreg << 8);
 284                 *((unsigned short*)insns + 2) = (*((unsigned short*)insns + 2) & 0xfff8) | (mreg + 1);
 285                 *((unsigned short*)insns + 3) = (*((unsigned short*)insns + 3) & 0xffc7) | (mreg << 3);
 286                 *((unsigned short*)insns + 7) = (*((unsigned short*)insns + 7) & 0xf8ff) | (mreg << 8);
 287                 *((unsigned short*)insns + 8) = (*((unsigned short*)insns + 8) & 0xffc7) | (mreg << 3);
 288                 *((unsigned short*)insns + 9) = (*((unsigned short*)insns + 9) & 0xffc7) | ((mreg + 1) << 3);
 289                 *((unsigned short*)insns + 10) = (*((unsigned short*)insns + 10) & 0x00ff) | (( 1 << mreg) | (1 << (mreg + 1)));
 290         }
 291
 292         if (THUMB_INSN_MATCH(APC, insn)) {
 293                 // ADD Rd, PC, #immed_8*4 -> ADD Rd, SP, #immed_8*4
 294                 *((unsigned short*)insns + 4) = ((insn & 0xffff) | 0x800);                              // ADD Rd, SP, #immed_8*4
 295         } else {
 296                 if (THUMB_INSN_MATCH(LRO3, insn)) {
 297                         // LDR Rd, [PC, #immed_8*4] -> LDR Rd, [SP, #immed_8*4]
 298                         *((unsigned short*)insns + 4) = ((insn & 0xffff) + 0x5000);                     // LDR Rd, [SP, #immed_8*4]
 299                 } else {
 300                         if (THUMB_INSN_MATCH(MOV3, insn)) {
 301                                 // MOV Rd, PC -> MOV Rd, SP
 302                                 *((unsigned short*)insns + 4) = ((insn & 0xffff) ^ 0x10);               // MOV Rd, SP
 303                         } else {
 304                                 if (THUMB2_INSN_MATCH(ADR, insn)) {
 305                                         // ADDW Rd, PC, #imm -> ADDW Rd, SP, #imm
 306                                         insns[2] = (insn & 0xfffffff0) | 0x0d;                          // ADDW Rd, SP, #imm
 307                                 } else {
 308                                         if (THUMB2_INSN_MATCH(LDRW, insn) || THUMB2_INSN_MATCH(LDRBW, insn) ||
 309                                             THUMB2_INSN_MATCH(LDRHW, insn)) {
 310                                                 // LDR.W Rt, [PC, #-<imm_12>] -> LDR.W Rt, [SP, #-<imm_8>]
 311                                                 // !!!!!!!!!!!!!!!!!!!!!!!!
 312                                                 // !!! imm_12 vs. imm_8 !!!
 313                                                 // !!!!!!!!!!!!!!!!!!!!!!!!
 314                                                 insns[2] = (insn & 0xf0fffff0) | 0x0c00000d;            // LDR.W Rt, [SP, #-<imm_8>]
 315                                         } else {
 316                                                 if (THUMB2_INSN_MATCH(LDRW1, insn) || THUMB2_INSN_MATCH(LDRBW1, insn) ||
 317                                                     THUMB2_INSN_MATCH(LDRHW1, insn) || THUMB2_INSN_MATCH(LDRD, insn) ||
 318                                                     THUMB2_INSN_MATCH(LDRD1, insn) || THUMB2_INSN_MATCH(LDREX, insn)) {
 319                                                         // LDRx.W Rt, [PC, #+<imm_12>] -> LDRx.W Rt, [SP, #+<imm_12>] (+/-imm_8 for LDRD Rt, Rt2, [PC, #<imm_8>]
 320                                                         insns[2] = (insn & 0xfffffff0) | 0xd;                                                                                                   // LDRx.W Rt, [SP, #+<imm_12>]
 321                                                 } else {
 322                                                         if (THUMB2_INSN_MATCH(MUL, insn)) {
 323                                                                 insns[2] = (insn & 0xfff0ffff) | 0x000d0000;                                                                                    // MUL Rd, Rn, SP
 324                                                         } else {
 325                                                                 if (THUMB2_INSN_MATCH(DP, insn)) {
 326                                                                         if (THUMB2_INSN_REG_RM(insn) == 15) {
 327                                                                                 insns[2] = (insn & 0xfff0ffff) | 0x000d0000;                                                                    // DP Rd, Rn, PC
 328                                                                         } else if (THUMB2_INSN_REG_RN(insn) == 15) {
 329                                                                                 insns[2] = (insn & 0xfffffff0) | 0xd;                                                                           // DP Rd, PC, Rm
 330                                                                         }
 331                                                                 } else {
 332                                                                         if (THUMB2_INSN_MATCH(LDRWL, insn)) {
 333                                                                                 // LDRx.W Rt, [PC, #<imm_12>] -> LDRx.W Rt, [SP, #+<imm_12>] (+/-imm_8 for LDRD Rt, Rt2, [PC, #<imm_8>]
 334                                                                                 insns[2] = (insn & 0xfffffff0) | 0xd;                                                                           // LDRx.W Rt, [SP, #+<imm_12>]
 335                                                                         } else {
 336                                                                                 if (THUMB2_INSN_MATCH(RSBW, insn)) {
 337                                                                                         insns[2] = (insn & 0xfffffff0) | 0xd;                                                                   // RSB{S}.W Rd, PC, #<const> -> RSB{S}.W Rd, SP, #<const>
 338                                                                                 } else {
 339                                                                                         if (THUMB2_INSN_MATCH(RORW, insn) || THUMB2_INSN_MATCH(LSLW1, insn) || THUMB2_INSN_MATCH(LSRW1, insn)) {
 340                                                                                                 if ((THUMB2_INSN_REG_RM(insn) == 15) && (THUMB2_INSN_REG_RN(insn) == 15)) {
 341                                                                                                         insns[2] = (insn & 0xfffdfffd);                                                         // ROR.W Rd, PC, PC
 342                                                                                                 } else if (THUMB2_INSN_REG_RM(insn) == 15) {
 343                                                                                                         insns[2] = (insn & 0xfff0ffff) | 0xd0000;                                               // ROR.W Rd, Rn, PC
 344                                                                                                 } else if (THUMB2_INSN_REG_RN(insn) == 15) {
 345                                                                                                         insns[2] = (insn & 0xfffffff0) | 0xd;                                                   // ROR.W Rd, PC, Rm
 346                                                                                                 }
 347                                                                                         } else {
 348                                                                                                 if (THUMB2_INSN_MATCH(ROR, insn) || THUMB2_INSN_MATCH(LSLW2, insn) || THUMB2_INSN_MATCH(LSRW2, insn)) {
 349                                                                                                         insns[2] = (insn & 0xfff0ffff) | 0xd0000;                                               // ROR{S} Rd, PC, #<const> -> ROR{S} Rd, SP, #<const>
 350                                                                                                 }
 351                                                                                         }
 352                                                                                 }
 353                                                                         }
 354                                                                 }
 355                                                         }
 356                                                 }
 357                                         }
 358                                 }
 359                         }
 360                 }
 361         }
 362
 363         if (THUMB2_INSN_MATCH(STRW, insn) || THUMB2_INSN_MATCH(STRBW, insn)) {
 364                 insns[2] = (insn & 0xfff0ffff) | 0x000d0000;                                                            // STRx.W Rt, [Rn, SP]
 365         } else {
 366                 if (THUMB2_INSN_MATCH(STRD, insn) || THUMB2_INSN_MATCH(STRHT, insn) ||
 367                     THUMB2_INSN_MATCH(STRT, insn) || THUMB2_INSN_MATCH(STRHW1, insn)) {
 368                         if (THUMB2_INSN_REG_RN(insn) == 15) {
 369                                 insns[2] = (insn & 0xfffffff0) | 0xd;                                                   // STRD/T/HT{.W} Rt, [SP, ...]
 370                         } else {
 371                                 insns[2] = insn;
 372                         }
 373                 } else {
 374                         if (THUMB2_INSN_MATCH(STRHW, insn) && (THUMB2_INSN_REG_RN(insn) == 15)) {
 375                                 if (THUMB2_INSN_REG_RN(insn) == 15) {
 376                                         insns[2] = (insn & 0xf0fffff0) | 0x0c00000d;                                    // STRH.W Rt, [SP, #-<imm_8>]
 377                                 } else {
 378                                         insns[2] = insn;
 379                                 }
 380                         }
 381                 }
 382         }
 383
 384         // STRx PC, xxx
 385         if ((reg == 15) && (THUMB2_INSN_MATCH(STRW, insn)   ||
 386                             THUMB2_INSN_MATCH(STRBW, insn)  ||
 387                             THUMB2_INSN_MATCH(STRD, insn)   ||
 388                             THUMB2_INSN_MATCH(STRHT, insn)  ||
 389                             THUMB2_INSN_MATCH(STRT, insn)   ||
 390                             THUMB2_INSN_MATCH(STRHW1, insn) ||
 391                             THUMB2_INSN_MATCH(STRHW, insn) )) {
 392                 insns[2] = (insns[2] & 0x0fffffff) | 0xd0000000;
 393         }
 394
 395         if (THUMB2_INSN_MATCH(TEQ1, insn) || THUMB2_INSN_MATCH(TST1, insn)) {
 396                 insns[2] = (insn & 0xfffffff0) | 0xd;                                                                   // TEQ SP, #<const>
 397         } else {
 398                 if (THUMB2_INSN_MATCH(TEQ2, insn) || THUMB2_INSN_MATCH(TST2, insn)) {
 399                         if ((THUMB2_INSN_REG_RN(insn) == 15) && (THUMB2_INSN_REG_RM(insn) == 15)) {
 400                                 insns[2] = (insn & 0xfffdfffd);                                                         // TEQ/TST PC, PC
 401                         } else if (THUMB2_INSN_REG_RM(insn) == 15) {
 402                                 insns[2] = (insn & 0xfff0ffff) | 0xd0000;                                               // TEQ/TST Rn, PC
 403                         } else if (THUMB2_INSN_REG_RN(insn) == 15) {
 404                                 insns[2] = (insn & 0xfffffff0) | 0xd;                                                   // TEQ/TST PC, Rm
 405                         }
 406                 }
 407         }
 408
 409         return 0;
 410 }
 411
 412 static int arch_copy_trampoline_thumb_uprobe(struct kprobe *p, struct task_struct *task, int atomic)
 413 {
 414         int uregs, pc_dep;
 415         unsigned int addr;
 416         kprobe_opcode_t insn[MAX_INSN_SIZE];
 417         struct arch_specific_insn ainsn;
 418         kprobe_opcode_t insns[UPROBES_TRAMP_LEN * 2];
 419
 420         p->safe_thumb = -1;
 421         if ((unsigned long)p->addr & 0x01) {
 422                 printk("Error in %s at %d: attempt to register kprobe at an unaligned address\n", __FILE__, __LINE__);
 423                 return -EINVAL;
 424         }
 425
 426         insn[0] = p->opcode;
 427         ainsn.insn_thumb = insn;
 428         if (!arch_check_insn_thumb(&ainsn)) {
 429                 p->safe_thumb = 0;
 430         }
 431
 432         uregs = 0;
 433         pc_dep = 0;
 434
 435         if (THUMB_INSN_MATCH(APC, insn[0]) || THUMB_INSN_MATCH(LRO3, insn[0])) {
 436                 uregs = 0x0700;         // 8-10
 437                 pc_dep = 1;
 438         } else if (THUMB_INSN_MATCH(MOV3, insn[0]) && (((((unsigned char)insn[0]) & 0xff) >> 3) == 15)) {
 439                 // MOV Rd, PC
 440                 uregs = 0x07;
 441                 pc_dep = 1;
 442         } else if THUMB2_INSN_MATCH(ADR, insn[0]) {
 443                 uregs = 0x0f00;         // Rd 8-11
 444                 pc_dep = 1;
 445         } else if (((THUMB2_INSN_MATCH(LDRW, insn[0]) || THUMB2_INSN_MATCH(LDRW1, insn[0]) ||
 446                      THUMB2_INSN_MATCH(LDRBW, insn[0]) || THUMB2_INSN_MATCH(LDRBW1, insn[0]) ||
 447                      THUMB2_INSN_MATCH(LDRHW, insn[0]) || THUMB2_INSN_MATCH(LDRHW1, insn[0]) ||
 448                      THUMB2_INSN_MATCH(LDRWL, insn[0])) && THUMB2_INSN_REG_RN(insn[0]) == 15) ||
 449                      THUMB2_INSN_MATCH(LDREX, insn[0]) ||
 450                      ((THUMB2_INSN_MATCH(STRW, insn[0]) || THUMB2_INSN_MATCH(STRBW, insn[0]) ||
 451                        THUMB2_INSN_MATCH(STRHW, insn[0]) || THUMB2_INSN_MATCH(STRHW1, insn[0])) &&
 452                       (THUMB2_INSN_REG_RN(insn[0]) == 15 || THUMB2_INSN_REG_RT(insn[0]) == 15)) ||
 453                      ((THUMB2_INSN_MATCH(STRT, insn[0]) || THUMB2_INSN_MATCH(STRHT, insn[0])) &&
 454                        (THUMB2_INSN_REG_RN(insn[0]) == 15 || THUMB2_INSN_REG_RT(insn[0]) == 15))) {
 455                 uregs = 0xf000;         // Rt 12-15
 456                 pc_dep = 1;
 457         } else if ((THUMB2_INSN_MATCH(LDRD, insn[0]) || THUMB2_INSN_MATCH(LDRD1, insn[0])) && (THUMB2_INSN_REG_RN(insn[0]) == 15)) {
 458                 uregs = 0xff00;         // Rt 12-15, Rt2 8-11
 459                 pc_dep = 1;
 460         } else if (THUMB2_INSN_MATCH(MUL, insn[0]) && THUMB2_INSN_REG_RM(insn[0]) == 15) {
 461                 uregs = 0xf;
 462                 pc_dep = 1;
 463         } else if (THUMB2_INSN_MATCH(DP, insn[0]) && (THUMB2_INSN_REG_RN(insn[0]) == 15 || THUMB2_INSN_REG_RM(insn[0]) == 15)) {
 464                 uregs = 0xf000;         // Rd 12-15
 465                 pc_dep = 1;
 466         } else if (THUMB2_INSN_MATCH(STRD, insn[0]) && ((THUMB2_INSN_REG_RN(insn[0]) == 15) || (THUMB2_INSN_REG_RT(insn[0]) == 15) || THUMB2_INSN_REG_RT2(insn[0]) == 15)) {
 467                 uregs = 0xff00;         // Rt 12-15, Rt2 8-11
 468                 pc_dep = 1;
 469         } else if (THUMB2_INSN_MATCH(RSBW, insn[0]) && THUMB2_INSN_REG_RN(insn[0]) == 15) {
 470                 uregs = 0x0f00;         // Rd 8-11
 471                 pc_dep = 1;
 472         } else if (THUMB2_INSN_MATCH (RORW, insn[0]) && (THUMB2_INSN_REG_RN(insn[0]) == 15 || THUMB2_INSN_REG_RM(insn[0]) == 15)) {
 473                 uregs = 0x0f00;
 474                 pc_dep = 1;
 475         } else if ((THUMB2_INSN_MATCH(ROR, insn[0]) || THUMB2_INSN_MATCH(LSLW2, insn[0]) || THUMB2_INSN_MATCH(LSRW2, insn[0])) && THUMB2_INSN_REG_RM(insn[0]) == 15) {
 476                 uregs = 0x0f00;         // Rd 8-11
 477                 pc_dep = 1;
 478         } else if ((THUMB2_INSN_MATCH(LSLW1, insn[0]) || THUMB2_INSN_MATCH(LSRW1, insn[0])) && (THUMB2_INSN_REG_RN(insn[0]) == 15 || THUMB2_INSN_REG_RM(insn[0]) == 15)) {
 479                 uregs = 0x0f00;         // Rd 8-11
 480                 pc_dep = 1;
 481         } else if ((THUMB2_INSN_MATCH(TEQ1, insn[0]) || THUMB2_INSN_MATCH(TST1, insn[0])) && THUMB2_INSN_REG_RN(insn[0]) == 15) {
 482                 uregs = 0xf0000;        //Rn 0-3 (16-19)
 483                 pc_dep = 1;
 484         } else if ((THUMB2_INSN_MATCH(TEQ2, insn[0]) || THUMB2_INSN_MATCH(TST2, insn[0])) &&
 485                    (THUMB2_INSN_REG_RN(insn[0]) == 15 || THUMB2_INSN_REG_RM(insn[0]) == 15)) {
 486                 uregs = 0xf0000;        //Rn 0-3 (16-19)
 487                 pc_dep = 1;
 488         }
 489
 490         if (unlikely(uregs && pc_dep)) {
 491                 memcpy(insns, pc_dep_insn_execbuf_thumb, 18 * 2);
 492                 if (prep_pc_dep_insn_execbuf_thumb(insns, insn[0], uregs) != 0) {
 493                         printk("Error in %s at %d: failed to prepare exec buffer for insn %lx!",
 494                                __FILE__, __LINE__, insn[0]);
 495                         p->safe_thumb = -1;
 496                         //free_insn_slot (&uprobe_insn_pages, task, p->ainsn.insn_thumb, 0);
 497                         //return -EINVAL;
 498                 }
 499
 500                 addr = ((unsigned int)p->addr) + 4;
 501                 *((unsigned short*)insns + 13) = 0xdeff;
 502                 *((unsigned short*)insns + 14) = addr & 0x0000ffff;
 503                 *((unsigned short*)insns + 15) = addr >> 16;
 504                 if (!is_thumb2(insn[0])) {
 505                         addr = ((unsigned int)p->addr) + 2;
 506                         *((unsigned short*)insns + 16) = (addr & 0x0000ffff) | 0x1;
 507                         *((unsigned short*)insns + 17) = addr >> 16;
 508                 } else {
 509                         addr = ((unsigned int)p->addr) + 4;
 510                         *((unsigned short*)insns + 16) = (addr & 0x0000ffff) | 0x1;
 511                         *((unsigned short*)insns + 17) = addr >> 16;
 512                 }
 513         } else {
 514                 memcpy(insns, gen_insn_execbuf_thumb, 18 * 2);
 515                 *((unsigned short*)insns + 13) = 0xdeff;
 516                 if (!is_thumb2(insn[0])) {
 517                         addr = ((unsigned int)p->addr) + 2;
 518                         *((unsigned short*)insns + 2) = insn[0];
 519                         *((unsigned short*)insns + 16) = (addr & 0x0000ffff) | 0x1;
 520                         *((unsigned short*)insns + 17) = addr >> 16;
 521                 } else {
 522                         addr = ((unsigned int)p->addr) + 4;
 523                         insns[1] = insn[0];
 524                         *((unsigned short*)insns + 16) = (addr & 0x0000ffff) | 0x1;
 525                         *((unsigned short*)insns + 17) = addr >> 16;
 526                 }
 527         }
 528
 529         if (!write_proc_vm_atomic (task, (unsigned long)p->ainsn.insn_thumb, insns, 18 * 2)) {
 530                 panic("failed to write memory %p!\n", p->ainsn.insn_thumb);
 531                 // Mr_Nobody: we have to panic, really??...
 532                 //free_insn_slot (&uprobe_insn_pages, task, p->ainsn.insn_thumb, 0);
 533                 //return -EINVAL;
 534         }
 535
 536         return 0;
 537 }
 538
 539 int arch_prepare_uprobe(struct kprobe *p, struct task_struct *task, int atomic)
 540 {
 541         int ret = 0;
 542         kprobe_opcode_t insn[MAX_INSN_SIZE];
 543
 544         if ((unsigned long)p->addr & 0x01) {
 545                 printk("Error in %s at %d: attempt to register kprobe at an unaligned address\n", __FILE__, __LINE__);
 546                 return -EINVAL;
 547         }
 548
 549         if (!read_proc_vm_atomic(task, (unsigned long)p->addr, &insn, MAX_INSN_SIZE * sizeof(kprobe_opcode_t))) {
 550                 panic("Failed to read memory task[tgid=%u, comm=%s] %p!\n", task->tgid, task->comm, p->addr);
 551         }
 552
 553         p->opcode = insn[0];
 554         p->ainsn.insn_arm = get_insn_slot(task, &uprobe_insn_pages, atomic);
 555         if (!p->ainsn.insn_arm) {
 556                 printk("Error in %s at %d: kprobe slot allocation error (arm)\n", __FILE__, __LINE__);
 557                 return -ENOMEM;
 558         }
 559
 560         ret = arch_copy_trampoline_arm_uprobe(p, task, 1);
 561         if (ret) {
 562                 free_insn_slot(&uprobe_insn_pages, task, p->ainsn.insn_arm);
 563                 return -EFAULT;
 564         }
 565
 566         p->ainsn.insn_thumb = get_insn_slot(task, &uprobe_insn_pages, atomic);
 567         if (!p->ainsn.insn_thumb) {
 568                 printk("Error in %s at %d: kprobe slot allocation error (thumb)\n", __FILE__, __LINE__);
 569                 return -ENOMEM;
 570         }
 571
 572         ret = arch_copy_trampoline_thumb_uprobe(p, task, 1);
 573         if (ret) {
 574                 free_insn_slot(&uprobe_insn_pages, task, p->ainsn.insn_arm);
 575                 free_insn_slot(&uprobe_insn_pages, task, p->ainsn.insn_thumb);
 576                 return -EFAULT;
 577         }
 578
 579         if ((p->safe_arm == -1) && (p->safe_thumb == -1)) {
 580                 printk("Error in %s at %d: failed arch_copy_trampoline_*_uprobe() (both) [tgid=%u, addr=%lx, data=%lx]\n",
 581                        __FILE__, __LINE__, task->tgid, (unsigned long)p->addr, (unsigned long)p->opcode);
 582                 if (!write_proc_vm_atomic(task, (unsigned long)p->addr, &p->opcode, sizeof(p->opcode))) {
 583                         panic("Failed to write memory %p!\n", p->addr);
 584                 }
 585
 586                 free_insn_slot(&uprobe_insn_pages, task, p->ainsn.insn_arm);
 587                 free_insn_slot(&uprobe_insn_pages, task, p->ainsn.insn_thumb);
 588
 589                 return -EFAULT;
 590         }
 591
 592         return ret;
 593 }
 594
 595 int setjmp_upre_handler(struct kprobe *p, struct pt_regs *regs)
 596 {
 597         struct jprobe *jp = container_of(p, struct jprobe, kp);
 598         kprobe_pre_entry_handler_t pre_entry = (kprobe_pre_entry_handler_t)jp->pre_entry;
 599         entry_point_t entry = (entry_point_t)jp->entry;
 600
 601         if (pre_entry) {
 602                 p->ss_addr = (kprobe_opcode_t *)pre_entry(jp->priv_arg, regs);
 603         }
 604
 605         if (entry) {
 606                 entry(regs->ARM_r0, regs->ARM_r1, regs->ARM_r2,
 607                       regs->ARM_r3, regs->ARM_r4, regs->ARM_r5);
 608         } else {
 609                 dbi_arch_uprobe_return();
 610         }
 611
 612         prepare_singlestep(p, regs);
 613
 614         return 1;
 615 }
 616
 617 static int check_validity_insn(struct kprobe *p, struct pt_regs *regs, struct task_struct *task)
 618 {
 619         struct kprobe *kp;
 620
 621         if (unlikely(thumb_mode(regs))) {
 622                 if (p->safe_thumb != -1) {
 623                         p->ainsn.insn = p->ainsn.insn_thumb;
 624                         list_for_each_entry_rcu(kp, &p->list, list) {
 625                                 kp->ainsn.insn = p->ainsn.insn_thumb;
 626                         }
 627                 } else {
 628                         printk("Error in %s at %d: we are in thumb mode (!) and check instruction was fail \
 629                                 (%0lX instruction at %p address)!\n", __FILE__, __LINE__, p->opcode, p->addr);
 630                         // Test case when we do our actions on already running application
 631                         arch_disarm_uprobe(p, task);
 632                         return -1;
 633                 }
 634         } else {
 635                 if (p->safe_arm != -1) {
 636                         p->ainsn.insn = p->ainsn.insn_arm;
 637                         list_for_each_entry_rcu(kp, &p->list, list) {
 638                                 kp->ainsn.insn = p->ainsn.insn_arm;
 639                         }
 640                 } else {
 641                         printk("Error in %s at %d: we are in arm mode (!) and check instruction was fail \
 642                                 (%0lX instruction at %p address)!\n", __FILE__, __LINE__, p->opcode, p->addr);
 643                         // Test case when we do our actions on already running application
 644                         arch_disarm_uprobe(p, task);
 645                         return -1;
 646                 }
 647         }
 648
 649         return 0;
 650 }
 651
 652 static int uprobe_handler(struct pt_regs *regs)
 653 {
 654         int err_out = 0;
 655         char *msg_out = NULL;
 656         struct task_struct *task = current;
 657         pid_t tgid = task->tgid;
 658         kprobe_opcode_t *addr = (kprobe_opcode_t *)(regs->ARM_pc);
 659         struct kprobe *p = NULL;
 660         int ret = 0, retprobe = 0;
 661         struct kprobe_ctlblk *kcb;
 662
 663 #ifdef SUPRESS_BUG_MESSAGES
 664         int swap_oops_in_progress;
 665         // oops_in_progress used to avoid BUG() messages that slow down kprobe_handler() execution
 666         swap_oops_in_progress = oops_in_progress;
 667         oops_in_progress = 1;
 668 #endif
 669
 670         p = get_kprobe(addr, tgid);
 671
 672         if (p && (check_validity_insn(p, regs, task) != 0)) {
 673                 goto no_uprobe_live;
 674         }
 675
 676         /* We're in an interrupt, but this is clear and BUG()-safe. */
 677         kcb = get_kprobe_ctlblk();
 678
 679         if (p == NULL) {
 680                 p = get_kprobe_by_insn_slot(addr, tgid, regs);
 681                 if (p == NULL) {
 682                         /* Not one of ours: let kernel handle it */
 683                         goto no_uprobe;
 684                 }
 685
 686                 retprobe = 1;
 687         }
 688
 689         /* restore opcode for thumb app */
 690         if (thumb_mode(regs)) {
 691                 if (!is_thumb2(p->opcode)) {
 692                         unsigned long tmp = p->opcode >> 16;
 693                         write_proc_vm_atomic(task, (unsigned long)((unsigned short*)p->addr + 1), &tmp, 2);
 694
 695                         // "2*sizeof(kprobe_opcode_t)" - strange. Should be "sizeof(kprobe_opcode_t)", need to test
 696                         flush_icache_range((unsigned int)p->addr, ((unsigned int)p->addr) + (2 * sizeof(kprobe_opcode_t)));
 697                 }
 698         }
 699
 700         set_current_kprobe(p, NULL, NULL);
 701         kcb->kprobe_status = KPROBE_HIT_ACTIVE;
 702
 703         if (retprobe) {
 704                 ret = trampoline_probe_handler(p, regs);
 705         } else if (p->pre_handler) {
 706                 ret = p->pre_handler(p, regs);
 707                 if(p->pre_handler != trampoline_probe_handler) {
 708                         reset_current_kprobe();
 709                 }
 710         }
 711
 712         if (ret) {
 713                 /* handler has already set things up, so skip ss setup */
 714                 err_out = 0;
 715                 goto out;
 716         }
 717
 718 no_uprobe:
 719         msg_out = "no_uprobe\n";
 720         err_out = 1;            // return with death
 721         goto out;
 722
 723 no_uprobe_live:
 724         msg_out = "no_uprobe live\n";
 725         err_out = 0;            // ok - life is life
 726         goto out;
 727
 728 out:
 729 #ifdef SUPRESS_BUG_MESSAGES
 730         oops_in_progress = swap_oops_in_progress;
 731 #endif
 732
 733         if(msg_out) {
 734                 printk(msg_out);
 735         }
 736
 737         return err_out;
 738 }
 739
 740 int uprobe_trap_handler(struct pt_regs *regs, unsigned int instr)
 741 {
 742         int ret;
 743         unsigned long flags;
 744         local_irq_save(flags);
 745
 746         preempt_disable();
 747         ret = uprobe_handler(regs);
 748         preempt_enable_no_resched();
 749
 750         local_irq_restore(flags);
 751         return ret;
 752 }
 753
 754 /* userspace probes hook (arm) */
 755 static struct undef_hook undef_hook_for_us_arm = {
 756         .instr_mask     = 0xffffffff,
 757         .instr_val      = BREAKPOINT_INSTRUCTION,
 758         .cpsr_mask      = MODE_MASK,
 759         .cpsr_val       = USR_MODE,
 760         .fn             = uprobe_trap_handler
 761 };
 762
 763 /* userspace probes hook (thumb) */
 764 static struct undef_hook undef_hook_for_us_thumb = {
 765         .instr_mask     = 0xffffffff,
 766         .instr_val      = BREAKPOINT_INSTRUCTION & 0x0000ffff,
 767         .cpsr_mask      = MODE_MASK,
 768         .cpsr_val       = USR_MODE,
 769         .fn             = uprobe_trap_handler
 770 };
 771
 772 int swap_arch_init_uprobes(void)
 773 {
 774         swap_register_undef_hook(&undef_hook_for_us_arm);
 775         swap_register_undef_hook(&undef_hook_for_us_thumb);
 776
 777         return 0;
 778 }
 779
 780 void swap_arch_exit_uprobes(void)
 781 {
 782         swap_unregister_undef_hook(&undef_hook_for_us_thumb);
 783         swap_unregister_undef_hook(&undef_hook_for_us_arm);
 784 }