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 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 11 | #include <linux/kernel.h> |
| 12 | #include <linux/sched.h> |
| 13 | #include <linux/mm.h> |
| 14 | #include <linux/smp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 15 | #include <linux/errno.h> |
| 16 | #include <linux/ptrace.h> |
| 17 | #include <linux/user.h> |
| 18 | #include <linux/slab.h> |
| 19 | #include <linux/security.h> |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 20 | #include <linux/signal.h> |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 21 | #include <linux/io.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 22 | #include <asm/uaccess.h> |
| 23 | #include <asm/pgtable.h> |
| 24 | #include <asm/system.h> |
| 25 | #include <asm/processor.h> |
| 26 | #include <asm/mmu_context.h> |
| 27 | |
| 28 | /* |
| 29 | * does not yet catch signals sent when the child dies. |
| 30 | * in exit.c or in signal.c. |
| 31 | */ |
| 32 | |
| 33 | /* |
| 34 | * This routine will get a word off of the process kernel stack. |
| 35 | */ |
| 36 | static inline int get_stack_long(struct task_struct *task, int offset) |
| 37 | { |
| 38 | unsigned char *stack; |
| 39 | |
Al Viro | 3cf0f4e | 2006-01-12 01:05:44 -0800 | [diff] [blame] | 40 | stack = (unsigned char *)task_pt_regs(task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 41 | stack += offset; |
| 42 | return (*((int *)stack)); |
| 43 | } |
| 44 | |
| 45 | /* |
| 46 | * This routine will put a word on the process kernel stack. |
| 47 | */ |
| 48 | static inline int put_stack_long(struct task_struct *task, int offset, |
| 49 | unsigned long data) |
| 50 | { |
| 51 | unsigned char *stack; |
| 52 | |
Al Viro | 3cf0f4e | 2006-01-12 01:05:44 -0800 | [diff] [blame] | 53 | stack = (unsigned char *)task_pt_regs(task); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | stack += offset; |
| 55 | *(unsigned long *) stack = data; |
| 56 | return 0; |
| 57 | } |
| 58 | |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 59 | static void ptrace_disable_singlestep(struct task_struct *child) |
| 60 | { |
| 61 | clear_tsk_thread_flag(child, TIF_SINGLESTEP); |
| 62 | |
| 63 | /* |
| 64 | * Ensure the UBC is not programmed at the next context switch. |
| 65 | * |
| 66 | * Normally this is not needed but there are sequences such as |
| 67 | * singlestep, signal delivery, and continue that leave the |
| 68 | * ubc_pc non-zero leading to spurious SIGTRAPs. |
| 69 | */ |
| 70 | if (child->thread.ubc_pc != 0) { |
| 71 | ubc_usercnt -= 1; |
| 72 | child->thread.ubc_pc = 0; |
| 73 | } |
| 74 | } |
| 75 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 76 | /* |
| 77 | * Called by kernel/ptrace.c when detaching.. |
| 78 | * |
| 79 | * Make sure single step bits etc are not set. |
| 80 | */ |
| 81 | void ptrace_disable(struct task_struct *child) |
| 82 | { |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 83 | ptrace_disable_singlestep(child); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 84 | } |
| 85 | |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 86 | long arch_ptrace(struct task_struct *child, long request, long addr, long data) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 87 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 88 | struct user * dummy = NULL; |
| 89 | int ret; |
| 90 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 91 | switch (request) { |
| 92 | /* when I and D space are separate, these will need to be fixed. */ |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 93 | case PTRACE_PEEKTEXT: /* read word at location addr. */ |
Alexey Dobriyan | 7664732 | 2007-07-17 04:03:43 -0700 | [diff] [blame] | 94 | case PTRACE_PEEKDATA: |
| 95 | ret = generic_ptrace_peekdata(child, addr, data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 96 | |
| 97 | /* read the word at location addr in the USER area. */ |
| 98 | case PTRACE_PEEKUSR: { |
| 99 | unsigned long tmp; |
| 100 | |
| 101 | ret = -EIO; |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 102 | if ((addr & 3) || addr < 0 || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 103 | addr > sizeof(struct user) - 3) |
| 104 | break; |
| 105 | |
| 106 | if (addr < sizeof(struct pt_regs)) |
| 107 | tmp = get_stack_long(child, addr); |
| 108 | else if (addr >= (long) &dummy->fpu && |
| 109 | addr < (long) &dummy->u_fpvalid) { |
| 110 | if (!tsk_used_math(child)) { |
| 111 | if (addr == (long)&dummy->fpu.fpscr) |
| 112 | tmp = FPSCR_INIT; |
| 113 | else |
| 114 | tmp = 0; |
| 115 | } else |
| 116 | tmp = ((long *)&child->thread.fpu) |
| 117 | [(addr - (long)&dummy->fpu) >> 2]; |
| 118 | } else if (addr == (long) &dummy->u_fpvalid) |
| 119 | tmp = !!tsk_used_math(child); |
| 120 | else |
| 121 | tmp = 0; |
Paul Mundt | e08f457 | 2007-05-14 12:52:56 +0900 | [diff] [blame] | 122 | ret = put_user(tmp, (unsigned long __user *)data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 123 | break; |
| 124 | } |
| 125 | |
| 126 | /* when I and D space are separate, this will have to be fixed. */ |
| 127 | case PTRACE_POKETEXT: /* write the word at location addr. */ |
| 128 | case PTRACE_POKEDATA: |
Alexey Dobriyan | f284ce7 | 2007-07-17 04:03:44 -0700 | [diff] [blame] | 129 | ret = generic_ptrace_pokedata(child, addr, data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | break; |
| 131 | |
| 132 | case PTRACE_POKEUSR: /* write the word at location addr in the USER area */ |
| 133 | ret = -EIO; |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 134 | if ((addr & 3) || addr < 0 || |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 135 | addr > sizeof(struct user) - 3) |
| 136 | break; |
| 137 | |
| 138 | if (addr < sizeof(struct pt_regs)) |
| 139 | ret = put_stack_long(child, addr, data); |
| 140 | else if (addr >= (long) &dummy->fpu && |
| 141 | addr < (long) &dummy->u_fpvalid) { |
| 142 | set_stopped_child_used_math(child); |
| 143 | ((long *)&child->thread.fpu) |
| 144 | [(addr - (long)&dummy->fpu) >> 2] = data; |
| 145 | ret = 0; |
| 146 | } else if (addr == (long) &dummy->u_fpvalid) { |
| 147 | conditional_stopped_child_used_math(data, child); |
| 148 | ret = 0; |
| 149 | } |
| 150 | break; |
| 151 | |
| 152 | case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */ |
| 153 | case PTRACE_CONT: { /* restart after signal. */ |
| 154 | ret = -EIO; |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 155 | if (!valid_signal(data)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 156 | break; |
| 157 | if (request == PTRACE_SYSCALL) |
| 158 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 159 | else |
| 160 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 161 | |
| 162 | ptrace_disable_singlestep(child); |
| 163 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 164 | child->exit_code = data; |
| 165 | wake_up_process(child); |
| 166 | ret = 0; |
| 167 | break; |
| 168 | } |
| 169 | |
| 170 | /* |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 171 | * make the child exit. Best I can do is send it a sigkill. |
| 172 | * perhaps it should be put in the status that it wants to |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 173 | * exit. |
| 174 | */ |
| 175 | case PTRACE_KILL: { |
| 176 | ret = 0; |
| 177 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ |
| 178 | break; |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 179 | ptrace_disable_singlestep(child); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 180 | child->exit_code = SIGKILL; |
| 181 | wake_up_process(child); |
| 182 | break; |
| 183 | } |
| 184 | |
| 185 | case PTRACE_SINGLESTEP: { /* set the trap flag. */ |
| 186 | long pc; |
Paul Mundt | e08f457 | 2007-05-14 12:52:56 +0900 | [diff] [blame] | 187 | struct pt_regs *regs = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
| 189 | ret = -EIO; |
Jesper Juhl | 7ed20e1 | 2005-05-01 08:59:14 -0700 | [diff] [blame] | 190 | if (!valid_signal(data)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | break; |
| 192 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 193 | if ((child->ptrace & PT_DTRACE) == 0) { |
| 194 | /* Spurious delayed TF traps may occur */ |
| 195 | child->ptrace |= PT_DTRACE; |
| 196 | } |
| 197 | |
Paul Mundt | e08f457 | 2007-05-14 12:52:56 +0900 | [diff] [blame] | 198 | pc = get_stack_long(child, (long)®s->pc); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 199 | |
| 200 | /* Next scheduling will set up UBC */ |
| 201 | if (child->thread.ubc_pc == 0) |
| 202 | ubc_usercnt += 1; |
| 203 | child->thread.ubc_pc = pc; |
| 204 | |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 205 | set_tsk_thread_flag(child, TIF_SINGLESTEP); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 206 | child->exit_code = data; |
| 207 | /* give it a chance to run. */ |
| 208 | wake_up_process(child); |
| 209 | ret = 0; |
| 210 | break; |
| 211 | } |
| 212 | |
| 213 | case PTRACE_DETACH: /* detach a process that was attached. */ |
| 214 | ret = ptrace_detach(child, data); |
| 215 | break; |
| 216 | |
| 217 | #ifdef CONFIG_SH_DSP |
| 218 | case PTRACE_GETDSPREGS: { |
| 219 | unsigned long dp; |
| 220 | |
| 221 | ret = -EIO; |
| 222 | dp = ((unsigned long) child) + THREAD_SIZE - |
| 223 | sizeof(struct pt_dspregs); |
| 224 | if (*((int *) (dp - 4)) == SR_FD) { |
| 225 | copy_to_user(addr, (void *) dp, |
| 226 | sizeof(struct pt_dspregs)); |
| 227 | ret = 0; |
| 228 | } |
| 229 | break; |
| 230 | } |
| 231 | |
| 232 | case PTRACE_SETDSPREGS: { |
| 233 | unsigned long dp; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | |
| 235 | ret = -EIO; |
| 236 | dp = ((unsigned long) child) + THREAD_SIZE - |
| 237 | sizeof(struct pt_dspregs); |
| 238 | if (*((int *) (dp - 4)) == SR_FD) { |
| 239 | copy_from_user((void *) dp, addr, |
| 240 | sizeof(struct pt_dspregs)); |
| 241 | ret = 0; |
| 242 | } |
| 243 | break; |
| 244 | } |
| 245 | #endif |
| 246 | default: |
| 247 | ret = ptrace_request(child, request, addr, data); |
| 248 | break; |
| 249 | } |
Christoph Hellwig | 481bed4 | 2005-11-07 00:59:47 -0800 | [diff] [blame] | 250 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 251 | return ret; |
| 252 | } |
| 253 | |
| 254 | asmlinkage void do_syscall_trace(void) |
| 255 | { |
| 256 | struct task_struct *tsk = current; |
| 257 | |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 258 | if (!test_thread_flag(TIF_SYSCALL_TRACE) && |
| 259 | !test_thread_flag(TIF_SINGLESTEP)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 260 | return; |
| 261 | if (!(tsk->ptrace & PT_PTRACED)) |
| 262 | return; |
| 263 | /* the 0x80 provides a way for the tracing parent to distinguish |
| 264 | between a syscall stop and SIGTRAP delivery */ |
Stuart Menefy | 9432f96 | 2007-02-23 13:22:17 +0900 | [diff] [blame] | 265 | ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) && |
| 266 | !test_thread_flag(TIF_SINGLESTEP) ? 0x80 : 0)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 267 | |
| 268 | /* |
| 269 | * this isn't the same as continuing with a signal, but it will do |
| 270 | * for normal use. strace only continues with a signal if the |
| 271 | * stopping signal is not SIGTRAP. -brl |
| 272 | */ |
| 273 | if (tsk->exit_code) { |
| 274 | send_sig(tsk->exit_code, tsk, 1); |
| 275 | tsk->exit_code = 0; |
| 276 | } |
| 277 | } |