1 // TODO some minor issues 2 /* 3 * This file is subject to the terms and conditions of the GNU General Public 4 * License. See the file "COPYING" in the main directory of this archive 5 * for more details. 6 * 7 * Copyright (C) 2001 - 2005 Tensilica Inc. 8 * 9 * Joe Taylor <joe@tensilica.com, joetylr@yahoo.com> 10 * Chris Zankel <chris@zankel.net> 11 * Scott Foehner<sfoehner@yahoo.com>, 12 * Kevin Chea 13 * Marc Gauthier<marc@tensilica.com> <marc@alumni.uwaterloo.ca> 14 */ 15 16 #include <linux/kernel.h> 17 #include <linux/sched.h> 18 #include <linux/mm.h> 19 #include <linux/errno.h> 20 #include <linux/ptrace.h> 21 #include <linux/smp.h> 22 #include <linux/security.h> 23 #include <linux/signal.h> 24 25 #include <asm/pgtable.h> 26 #include <asm/page.h> 27 #include <asm/system.h> 28 #include <asm/uaccess.h> 29 #include <asm/ptrace.h> 30 #include <asm/elf.h> 31 32 #define TEST_KERNEL // verify kernel operations FIXME: remove 33 34 35 /* 36 * Called by kernel/ptrace.c when detaching.. 37 * 38 * Make sure single step bits etc are not set. 39 */ 40 41 void ptrace_disable(struct task_struct *child) 42 { 43 /* Nothing to do.. */ 44 } 45 46 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 47 { 48 int ret = -EPERM; 49 50 switch (request) { 51 case PTRACE_PEEKTEXT: /* read word at location addr. */ 52 case PTRACE_PEEKDATA: 53 ret = generic_ptrace_peekdata(child, addr, data); 54 goto out; 55 56 /* Read the word at location addr in the USER area. */ 57 58 case PTRACE_PEEKUSR: 59 { 60 struct pt_regs *regs; 61 unsigned long tmp; 62 63 regs = task_pt_regs(child); 64 tmp = 0; /* Default return value. */ 65 66 switch(addr) { 67 68 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1: 69 { 70 int ar = addr - REG_AR_BASE - regs->windowbase * 4; 71 ar &= (XCHAL_NUM_AREGS - 1); 72 if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0) 73 tmp = regs->areg[ar]; 74 else 75 ret = -EIO; 76 break; 77 } 78 case REG_A_BASE ... REG_A_BASE + 15: 79 tmp = regs->areg[addr - REG_A_BASE]; 80 break; 81 case REG_PC: 82 tmp = regs->pc; 83 break; 84 case REG_PS: 85 /* Note: PS.EXCM is not set while user task is running; 86 * its being set in regs is for exception handling 87 * convenience. */ 88 tmp = (regs->ps & ~(1 << PS_EXCM_BIT)); 89 break; 90 case REG_WB: 91 tmp = regs->windowbase; 92 break; 93 case REG_WS: 94 tmp = regs->windowstart; 95 break; 96 case REG_LBEG: 97 tmp = regs->lbeg; 98 break; 99 case REG_LEND: 100 tmp = regs->lend; 101 break; 102 case REG_LCOUNT: 103 tmp = regs->lcount; 104 break; 105 case REG_SAR: 106 tmp = regs->sar; 107 break; 108 case REG_DEPC: 109 tmp = regs->depc; 110 break; 111 case REG_EXCCAUSE: 112 tmp = regs->exccause; 113 break; 114 case REG_EXCVADDR: 115 tmp = regs->excvaddr; 116 break; 117 case SYSCALL_NR: 118 tmp = regs->syscall; 119 break; 120 default: 121 tmp = 0; 122 ret = -EIO; 123 goto out; 124 } 125 ret = put_user(tmp, (unsigned long *) data); 126 goto out; 127 } 128 129 case PTRACE_POKETEXT: /* write the word at location addr. */ 130 case PTRACE_POKEDATA: 131 ret = generic_ptrace_pokedata(child, addr, data); 132 goto out; 133 134 case PTRACE_POKEUSR: 135 { 136 struct pt_regs *regs; 137 regs = task_pt_regs(child); 138 139 switch (addr) { 140 case REG_AR_BASE ... REG_AR_BASE + XCHAL_NUM_AREGS - 1: 141 { 142 int ar = addr - REG_AR_BASE - regs->windowbase * 4; 143 if (ar < 16 && ar + (regs->wmask >> 4) * 4 >= 0) 144 regs->areg[ar & (XCHAL_NUM_AREGS - 1)] = data; 145 else 146 ret = -EIO; 147 break; 148 } 149 case REG_A_BASE ... REG_A_BASE + 15: 150 regs->areg[addr - REG_A_BASE] = data; 151 break; 152 case REG_PC: 153 regs->pc = data; 154 break; 155 case SYSCALL_NR: 156 regs->syscall = data; 157 break; 158 #ifdef TEST_KERNEL 159 case REG_WB: 160 regs->windowbase = data; 161 break; 162 case REG_WS: 163 regs->windowstart = data; 164 break; 165 #endif 166 167 default: 168 /* The rest are not allowed. */ 169 ret = -EIO; 170 break; 171 } 172 break; 173 } 174 175 /* continue and stop at next (return from) syscall */ 176 case PTRACE_SYSCALL: 177 case PTRACE_CONT: /* restart after signal. */ 178 { 179 ret = -EIO; 180 if (!valid_signal(data)) 181 break; 182 if (request == PTRACE_SYSCALL) 183 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 184 else 185 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 186 child->exit_code = data; 187 /* Make sure the single step bit is not set. */ 188 child->ptrace &= ~PT_SINGLESTEP; 189 wake_up_process(child); 190 ret = 0; 191 break; 192 } 193 194 /* 195 * make the child exit. Best I can do is send it a sigkill. 196 * perhaps it should be put in the status that it wants to 197 * exit. 198 */ 199 case PTRACE_KILL: 200 ret = 0; 201 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 202 break; 203 child->exit_code = SIGKILL; 204 child->ptrace &= ~PT_SINGLESTEP; 205 wake_up_process(child); 206 break; 207 208 case PTRACE_SINGLESTEP: 209 ret = -EIO; 210 if (!valid_signal(data)) 211 break; 212 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 213 child->ptrace |= PT_SINGLESTEP; 214 child->exit_code = data; 215 wake_up_process(child); 216 ret = 0; 217 break; 218 219 case PTRACE_GETREGS: 220 { 221 /* 'data' points to user memory in which to write. 222 * Mainly due to the non-live register values, we 223 * reformat the register values into something more 224 * standard. For convenience, we use the handy 225 * elf_gregset_t format. */ 226 227 xtensa_gregset_t format; 228 struct pt_regs *regs = task_pt_regs(child); 229 230 do_copy_regs (&format, regs, child); 231 232 /* Now, copy to user space nice and easy... */ 233 ret = 0; 234 if (copy_to_user((void *)data, &format, sizeof(elf_gregset_t))) 235 ret = -EFAULT; 236 break; 237 } 238 239 case PTRACE_SETREGS: 240 { 241 /* 'data' points to user memory that contains the new 242 * values in the elf_gregset_t format. */ 243 244 xtensa_gregset_t format; 245 struct pt_regs *regs = task_pt_regs(child); 246 247 if (copy_from_user(&format,(void *)data,sizeof(elf_gregset_t))){ 248 ret = -EFAULT; 249 break; 250 } 251 252 /* FIXME: Perhaps we want some sanity checks on 253 * these user-space values? See ARM version. Are 254 * debuggers a security concern? */ 255 256 do_restore_regs (&format, regs, child); 257 258 ret = 0; 259 break; 260 } 261 262 case PTRACE_GETFPREGS: 263 { 264 /* 'data' points to user memory in which to write. 265 * For convenience, we use the handy 266 * elf_fpregset_t format. */ 267 268 elf_fpregset_t fpregs; 269 struct pt_regs *regs = task_pt_regs(child); 270 271 do_save_fpregs (&fpregs, regs, child); 272 273 /* Now, copy to user space nice and easy... */ 274 ret = 0; 275 if (copy_to_user((void *)data, &fpregs, sizeof(elf_fpregset_t))) 276 ret = -EFAULT; 277 278 break; 279 } 280 281 case PTRACE_SETFPREGS: 282 { 283 /* 'data' points to user memory that contains the new 284 * values in the elf_fpregset_t format. 285 */ 286 elf_fpregset_t fpregs; 287 struct pt_regs *regs = task_pt_regs(child); 288 289 ret = 0; 290 if (copy_from_user(&fpregs, (void *)data, sizeof(elf_fpregset_t))) { 291 ret = -EFAULT; 292 break; 293 } 294 295 if (do_restore_fpregs (&fpregs, regs, child)) 296 ret = -EIO; 297 break; 298 } 299 300 case PTRACE_GETFPREGSIZE: 301 /* 'data' points to 'unsigned long' set to the size 302 * of elf_fpregset_t 303 */ 304 ret = put_user(sizeof(elf_fpregset_t), (unsigned long *) data); 305 break; 306 307 default: 308 ret = ptrace_request(child, request, addr, data); 309 goto out; 310 } 311 out: 312 return ret; 313 } 314 315 void do_syscall_trace(void) 316 { 317 /* 318 * The 0x80 provides a way for the tracing parent to distinguish 319 * between a syscall stop and SIGTRAP delivery 320 */ 321 ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); 322 323 /* 324 * this isn't the same as continuing with a signal, but it will do 325 * for normal use. strace only continues with a signal if the 326 * stopping signal is not SIGTRAP. -brl 327 */ 328 if (current->exit_code) { 329 send_sig(current->exit_code, current, 1); 330 current->exit_code = 0; 331 } 332 } 333 334 void do_syscall_trace_enter(struct pt_regs *regs) 335 { 336 if (test_thread_flag(TIF_SYSCALL_TRACE) 337 && (current->ptrace & PT_PTRACED)) 338 do_syscall_trace(); 339 340 #if 0 341 if (unlikely(current->audit_context)) 342 audit_syscall_entry(current, AUDIT_ARCH_XTENSA..); 343 #endif 344 } 345 346 void do_syscall_trace_leave(struct pt_regs *regs) 347 { 348 if ((test_thread_flag(TIF_SYSCALL_TRACE)) 349 && (current->ptrace & PT_PTRACED)) 350 do_syscall_trace(); 351 } 352 353