1 /* 2 * linux/arch/sh/kernel/ptrace.c 3 * 4 * Original x86 implementation: 5 * By Ross Biro 1/23/92 6 * edited by Linus Torvalds 7 * 8 * SuperH version: Copyright (C) 1999, 2000 Kaz Kojima & Niibe Yutaka 9 * 10 */ 11 12 #include <linux/config.h> 13 #include <linux/kernel.h> 14 #include <linux/sched.h> 15 #include <linux/mm.h> 16 #include <linux/smp.h> 17 #include <linux/smp_lock.h> 18 #include <linux/errno.h> 19 #include <linux/ptrace.h> 20 #include <linux/user.h> 21 #include <linux/slab.h> 22 #include <linux/security.h> 23 #include <linux/signal.h> 24 25 #include <asm/io.h> 26 #include <asm/uaccess.h> 27 #include <asm/pgtable.h> 28 #include <asm/system.h> 29 #include <asm/processor.h> 30 #include <asm/mmu_context.h> 31 32 /* 33 * does not yet catch signals sent when the child dies. 34 * in exit.c or in signal.c. 35 */ 36 37 /* 38 * This routine will get a word off of the process kernel stack. 39 */ 40 static inline int get_stack_long(struct task_struct *task, int offset) 41 { 42 unsigned char *stack; 43 44 stack = (unsigned char *) 45 task->thread_info + THREAD_SIZE - sizeof(struct pt_regs) 46 #ifdef CONFIG_SH_DSP 47 - sizeof(struct pt_dspregs) 48 #endif 49 - sizeof(unsigned long); 50 stack += offset; 51 return (*((int *)stack)); 52 } 53 54 /* 55 * This routine will put a word on the process kernel stack. 56 */ 57 static inline int put_stack_long(struct task_struct *task, int offset, 58 unsigned long data) 59 { 60 unsigned char *stack; 61 62 stack = (unsigned char *) 63 task->thread_info + THREAD_SIZE - sizeof(struct pt_regs) 64 #ifdef CONFIG_SH_DSP 65 - sizeof(struct pt_dspregs) 66 #endif 67 - sizeof(unsigned long); 68 stack += offset; 69 *(unsigned long *) stack = data; 70 return 0; 71 } 72 73 /* 74 * Called by kernel/ptrace.c when detaching.. 75 * 76 * Make sure single step bits etc are not set. 77 */ 78 void ptrace_disable(struct task_struct *child) 79 { 80 /* nothing to do.. */ 81 } 82 83 long arch_ptrace(struct task_struct *child, long request, long addr, long data) 84 { 85 struct user * dummy = NULL; 86 int ret; 87 88 switch (request) { 89 /* when I and D space are separate, these will need to be fixed. */ 90 case PTRACE_PEEKTEXT: /* read word at location addr. */ 91 case PTRACE_PEEKDATA: { 92 unsigned long tmp; 93 int copied; 94 95 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); 96 ret = -EIO; 97 if (copied != sizeof(tmp)) 98 break; 99 ret = put_user(tmp,(unsigned long *) data); 100 break; 101 } 102 103 /* read the word at location addr in the USER area. */ 104 case PTRACE_PEEKUSR: { 105 unsigned long tmp; 106 107 ret = -EIO; 108 if ((addr & 3) || addr < 0 || 109 addr > sizeof(struct user) - 3) 110 break; 111 112 if (addr < sizeof(struct pt_regs)) 113 tmp = get_stack_long(child, addr); 114 else if (addr >= (long) &dummy->fpu && 115 addr < (long) &dummy->u_fpvalid) { 116 if (!tsk_used_math(child)) { 117 if (addr == (long)&dummy->fpu.fpscr) 118 tmp = FPSCR_INIT; 119 else 120 tmp = 0; 121 } else 122 tmp = ((long *)&child->thread.fpu) 123 [(addr - (long)&dummy->fpu) >> 2]; 124 } else if (addr == (long) &dummy->u_fpvalid) 125 tmp = !!tsk_used_math(child); 126 else 127 tmp = 0; 128 ret = put_user(tmp, (unsigned long *)data); 129 break; 130 } 131 132 /* when I and D space are separate, this will have to be fixed. */ 133 case PTRACE_POKETEXT: /* write the word at location addr. */ 134 case PTRACE_POKEDATA: 135 ret = 0; 136 if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) 137 break; 138 ret = -EIO; 139 break; 140 141 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ 142 ret = -EIO; 143 if ((addr & 3) || addr < 0 || 144 addr > sizeof(struct user) - 3) 145 break; 146 147 if (addr < sizeof(struct pt_regs)) 148 ret = put_stack_long(child, addr, data); 149 else if (addr >= (long) &dummy->fpu && 150 addr < (long) &dummy->u_fpvalid) { 151 set_stopped_child_used_math(child); 152 ((long *)&child->thread.fpu) 153 [(addr - (long)&dummy->fpu) >> 2] = data; 154 ret = 0; 155 } else if (addr == (long) &dummy->u_fpvalid) { 156 conditional_stopped_child_used_math(data, child); 157 ret = 0; 158 } 159 break; 160 161 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ 162 case PTRACE_CONT: { /* restart after signal. */ 163 ret = -EIO; 164 if (!valid_signal(data)) 165 break; 166 if (request == PTRACE_SYSCALL) 167 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 168 else 169 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 170 child->exit_code = data; 171 wake_up_process(child); 172 ret = 0; 173 break; 174 } 175 176 /* 177 * make the child exit. Best I can do is send it a sigkill. 178 * perhaps it should be put in the status that it wants to 179 * exit. 180 */ 181 case PTRACE_KILL: { 182 ret = 0; 183 if (child->exit_state == EXIT_ZOMBIE) /* already dead */ 184 break; 185 child->exit_code = SIGKILL; 186 wake_up_process(child); 187 break; 188 } 189 190 case PTRACE_SINGLESTEP: { /* set the trap flag. */ 191 long pc; 192 struct pt_regs *dummy = NULL; 193 194 ret = -EIO; 195 if (!valid_signal(data)) 196 break; 197 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 198 if ((child->ptrace & PT_DTRACE) == 0) { 199 /* Spurious delayed TF traps may occur */ 200 child->ptrace |= PT_DTRACE; 201 } 202 203 pc = get_stack_long(child, (long)&dummy->pc); 204 205 /* Next scheduling will set up UBC */ 206 if (child->thread.ubc_pc == 0) 207 ubc_usercnt += 1; 208 child->thread.ubc_pc = pc; 209 210 child->exit_code = data; 211 /* give it a chance to run. */ 212 wake_up_process(child); 213 ret = 0; 214 break; 215 } 216 217 case PTRACE_DETACH: /* detach a process that was attached. */ 218 ret = ptrace_detach(child, data); 219 break; 220 221 #ifdef CONFIG_SH_DSP 222 case PTRACE_GETDSPREGS: { 223 unsigned long dp; 224 225 ret = -EIO; 226 dp = ((unsigned long) child) + THREAD_SIZE - 227 sizeof(struct pt_dspregs); 228 if (*((int *) (dp - 4)) == SR_FD) { 229 copy_to_user(addr, (void *) dp, 230 sizeof(struct pt_dspregs)); 231 ret = 0; 232 } 233 break; 234 } 235 236 case PTRACE_SETDSPREGS: { 237 unsigned long dp; 238 int i; 239 240 ret = -EIO; 241 dp = ((unsigned long) child) + THREAD_SIZE - 242 sizeof(struct pt_dspregs); 243 if (*((int *) (dp - 4)) == SR_FD) { 244 copy_from_user((void *) dp, addr, 245 sizeof(struct pt_dspregs)); 246 ret = 0; 247 } 248 break; 249 } 250 #endif 251 default: 252 ret = ptrace_request(child, request, addr, data); 253 break; 254 } 255 256 return ret; 257 } 258 259 asmlinkage void do_syscall_trace(void) 260 { 261 struct task_struct *tsk = current; 262 263 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 264 return; 265 if (!(tsk->ptrace & PT_PTRACED)) 266 return; 267 /* the 0x80 provides a way for the tracing parent to distinguish 268 between a syscall stop and SIGTRAP delivery */ 269 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) 270 ? 0x80 : 0)); 271 272 /* 273 * this isn't the same as continuing with a signal, but it will do 274 * for normal use. strace only continues with a signal if the 275 * stopping signal is not SIGTRAP. -brl 276 */ 277 if (tsk->exit_code) { 278 send_sig(tsk->exit_code, tsk, 1); 279 tsk->exit_code = 0; 280 } 281 } 282