Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 23 | #include <linux/signal.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | asmlinkage int sys_ptrace(long request, long pid, long addr, long data) |
| 84 | { |
| 85 | struct task_struct *child; |
| 86 | struct user * dummy = NULL; |
| 87 | int ret; |
| 88 | |
| 89 | lock_kernel(); |
| 90 | ret = -EPERM; |
| 91 | if (request == PTRACE_TRACEME) { |
| 92 | /* are we already being traced? */ |
| 93 | if (current->ptrace & PT_PTRACED) |
| 94 | goto out; |
| 95 | ret = security_ptrace(current->parent, current); |
| 96 | if (ret) |
| 97 | goto out; |
| 98 | /* set the ptrace bit in the process flags. */ |
| 99 | current->ptrace |= PT_PTRACED; |
| 100 | ret = 0; |
| 101 | goto out; |
| 102 | } |
| 103 | ret = -ESRCH; |
| 104 | read_lock(&tasklist_lock); |
| 105 | child = find_task_by_pid(pid); |
| 106 | if (child) |
| 107 | get_task_struct(child); |
| 108 | read_unlock(&tasklist_lock); |
| 109 | if (!child) |
| 110 | goto out; |
| 111 | |
| 112 | ret = -EPERM; |
| 113 | if (pid == 1) /* you may not mess with init */ |
| 114 | goto out_tsk; |
| 115 | |
| 116 | if (request == PTRACE_ATTACH) { |
| 117 | ret = ptrace_attach(child); |
| 118 | goto out_tsk; |
| 119 | } |
| 120 | |
| 121 | ret = ptrace_check_attach(child, request == PTRACE_KILL); |
| 122 | if (ret < 0) |
| 123 | goto out_tsk; |
| 124 | |
| 125 | switch (request) { |
| 126 | /* when I and D space are separate, these will need to be fixed. */ |
| 127 | case PTRACE_PEEKTEXT: /* read word at location addr. */ |
| 128 | case PTRACE_PEEKDATA: { |
| 129 | unsigned long tmp; |
| 130 | int copied; |
| 131 | |
| 132 | copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0); |
| 133 | ret = -EIO; |
| 134 | if (copied != sizeof(tmp)) |
| 135 | break; |
| 136 | ret = put_user(tmp,(unsigned long *) data); |
| 137 | break; |
| 138 | } |
| 139 | |
| 140 | /* read the word at location addr in the USER area. */ |
| 141 | case PTRACE_PEEKUSR: { |
| 142 | unsigned long tmp; |
| 143 | |
| 144 | ret = -EIO; |
| 145 | if ((addr & 3) || addr < 0 || |
| 146 | addr > sizeof(struct user) - 3) |
| 147 | break; |
| 148 | |
| 149 | if (addr < sizeof(struct pt_regs)) |
| 150 | tmp = get_stack_long(child, addr); |
| 151 | else if (addr >= (long) &dummy->fpu && |
| 152 | addr < (long) &dummy->u_fpvalid) { |
| 153 | if (!tsk_used_math(child)) { |
| 154 | if (addr == (long)&dummy->fpu.fpscr) |
| 155 | tmp = FPSCR_INIT; |
| 156 | else |
| 157 | tmp = 0; |
| 158 | } else |
| 159 | tmp = ((long *)&child->thread.fpu) |
| 160 | [(addr - (long)&dummy->fpu) >> 2]; |
| 161 | } else if (addr == (long) &dummy->u_fpvalid) |
| 162 | tmp = !!tsk_used_math(child); |
| 163 | else |
| 164 | tmp = 0; |
| 165 | ret = put_user(tmp, (unsigned long *)data); |
| 166 | break; |
| 167 | } |
| 168 | |
| 169 | /* when I and D space are separate, this will have to be fixed. */ |
| 170 | case PTRACE_POKETEXT: /* write the word at location addr. */ |
| 171 | case PTRACE_POKEDATA: |
| 172 | ret = 0; |
| 173 | if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data)) |
| 174 | break; |
| 175 | ret = -EIO; |
| 176 | break; |
| 177 | |
| 178 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ |
| 179 | ret = -EIO; |
| 180 | if ((addr & 3) || addr < 0 || |
| 181 | addr > sizeof(struct user) - 3) |
| 182 | break; |
| 183 | |
| 184 | if (addr < sizeof(struct pt_regs)) |
| 185 | ret = put_stack_long(child, addr, data); |
| 186 | else if (addr >= (long) &dummy->fpu && |
| 187 | addr < (long) &dummy->u_fpvalid) { |
| 188 | set_stopped_child_used_math(child); |
| 189 | ((long *)&child->thread.fpu) |
| 190 | [(addr - (long)&dummy->fpu) >> 2] = data; |
| 191 | ret = 0; |
| 192 | } else if (addr == (long) &dummy->u_fpvalid) { |
| 193 | conditional_stopped_child_used_math(data, child); |
| 194 | ret = 0; |
| 195 | } |
| 196 | break; |
| 197 | |
| 198 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ |
| 199 | case PTRACE_CONT: { /* restart after signal. */ |
| 200 | ret = -EIO; |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 201 | if (!valid_signal(data)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | break; |
| 203 | if (request == PTRACE_SYSCALL) |
| 204 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 205 | else |
| 206 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 207 | child->exit_code = data; |
| 208 | wake_up_process(child); |
| 209 | ret = 0; |
| 210 | break; |
| 211 | } |
| 212 | |
| 213 | /* |
| 214 | * make the child exit. Best I can do is send it a sigkill. |
| 215 | * perhaps it should be put in the status that it wants to |
| 216 | * exit. |
| 217 | */ |
| 218 | case PTRACE_KILL: { |
| 219 | ret = 0; |
| 220 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ |
| 221 | break; |
| 222 | child->exit_code = SIGKILL; |
| 223 | wake_up_process(child); |
| 224 | break; |
| 225 | } |
| 226 | |
| 227 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ |
| 228 | long pc; |
| 229 | struct pt_regs *dummy = NULL; |
| 230 | |
| 231 | ret = -EIO; |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 232 | if (!valid_signal(data)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | break; |
| 234 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 235 | if ((child->ptrace & PT_DTRACE) == 0) { |
| 236 | /* Spurious delayed TF traps may occur */ |
| 237 | child->ptrace |= PT_DTRACE; |
| 238 | } |
| 239 | |
| 240 | pc = get_stack_long(child, (long)&dummy->pc); |
| 241 | |
| 242 | /* Next scheduling will set up UBC */ |
| 243 | if (child->thread.ubc_pc == 0) |
| 244 | ubc_usercnt += 1; |
| 245 | child->thread.ubc_pc = pc; |
| 246 | |
| 247 | child->exit_code = data; |
| 248 | /* give it a chance to run. */ |
| 249 | wake_up_process(child); |
| 250 | ret = 0; |
| 251 | break; |
| 252 | } |
| 253 | |
| 254 | case PTRACE_DETACH: /* detach a process that was attached. */ |
| 255 | ret = ptrace_detach(child, data); |
| 256 | break; |
| 257 | |
| 258 | #ifdef CONFIG_SH_DSP |
| 259 | case PTRACE_GETDSPREGS: { |
| 260 | unsigned long dp; |
| 261 | |
| 262 | ret = -EIO; |
| 263 | dp = ((unsigned long) child) + THREAD_SIZE - |
| 264 | sizeof(struct pt_dspregs); |
| 265 | if (*((int *) (dp - 4)) == SR_FD) { |
| 266 | copy_to_user(addr, (void *) dp, |
| 267 | sizeof(struct pt_dspregs)); |
| 268 | ret = 0; |
| 269 | } |
| 270 | break; |
| 271 | } |
| 272 | |
| 273 | case PTRACE_SETDSPREGS: { |
| 274 | unsigned long dp; |
| 275 | int i; |
| 276 | |
| 277 | ret = -EIO; |
| 278 | dp = ((unsigned long) child) + THREAD_SIZE - |
| 279 | sizeof(struct pt_dspregs); |
| 280 | if (*((int *) (dp - 4)) == SR_FD) { |
| 281 | copy_from_user((void *) dp, addr, |
| 282 | sizeof(struct pt_dspregs)); |
| 283 | ret = 0; |
| 284 | } |
| 285 | break; |
| 286 | } |
| 287 | #endif |
| 288 | default: |
| 289 | ret = ptrace_request(child, request, addr, data); |
| 290 | break; |
| 291 | } |
| 292 | out_tsk: |
| 293 | put_task_struct(child); |
| 294 | out: |
| 295 | unlock_kernel(); |
| 296 | return ret; |
| 297 | } |
| 298 | |
| 299 | asmlinkage void do_syscall_trace(void) |
| 300 | { |
| 301 | struct task_struct *tsk = current; |
| 302 | |
| 303 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| 304 | return; |
| 305 | if (!(tsk->ptrace & PT_PTRACED)) |
| 306 | return; |
| 307 | /* the 0x80 provides a way for the tracing parent to distinguish |
| 308 | between a syscall stop and SIGTRAP delivery */ |
| 309 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) |
| 310 | ? 0x80 : 0)); |
| 311 | |
| 312 | /* |
| 313 | * this isn't the same as continuing with a signal, but it will do |
| 314 | * for normal use. strace only continues with a signal if the |
| 315 | * stopping signal is not SIGTRAP. -brl |
| 316 | */ |
| 317 | if (tsk->exit_code) { |
| 318 | send_sig(tsk->exit_code, tsk, 1); |
| 319 | tsk->exit_code = 0; |
| 320 | } |
| 321 | } |