| 1 | /* |
| 2 | * arch/ubicom32/kernel/ptrace.c |
| 3 | * Ubicom32 architecture ptrace implementation. |
| 4 | * |
| 5 | * (C) Copyright 2009, Ubicom, Inc. |
| 6 | * (C) 1994 by Hamish Macdonald |
| 7 | * Taken from linux/kernel/ptrace.c and modified for M680x0. |
| 8 | * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds |
| 9 | * |
| 10 | * This file is part of the Ubicom32 Linux Kernel Port. |
| 11 | * |
| 12 | * The Ubicom32 Linux Kernel Port is free software: you can redistribute |
| 13 | * it and/or modify it under the terms of the GNU General Public License |
| 14 | * as published by the Free Software Foundation, either version 2 of the |
| 15 | * License, or (at your option) any later version. |
| 16 | * |
| 17 | * The Ubicom32 Linux Kernel Port is distributed in the hope that it |
| 18 | * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| 19 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See |
| 20 | * the GNU General Public License for more details. |
| 21 | * |
| 22 | * You should have received a copy of the GNU General Public License |
| 23 | * along with the Ubicom32 Linux Kernel Port. If not, |
| 24 | * see <http://www.gnu.org/licenses/>. |
| 25 | * |
| 26 | * Ubicom32 implementation derived from (with many thanks): |
| 27 | * arch/m68knommu |
| 28 | * arch/blackfin |
| 29 | * arch/parisc |
| 30 | */ |
| 31 | |
| 32 | #include <linux/module.h> |
| 33 | #include <linux/kernel.h> |
| 34 | #include <linux/sched.h> |
| 35 | #include <linux/mm.h> |
| 36 | #include <linux/smp.h> |
| 37 | #include <linux/errno.h> |
| 38 | #include <linux/ptrace.h> |
| 39 | #include <linux/user.h> |
| 40 | #include <linux/signal.h> |
| 41 | #include <linux/uaccess.h> |
| 42 | |
| 43 | #include <asm/page.h> |
| 44 | #include <asm/pgtable.h> |
| 45 | #include <asm/system.h> |
| 46 | #include <asm/cacheflush.h> |
| 47 | #include <asm/processor.h> |
| 48 | |
| 49 | /* |
| 50 | * ptrace_getregs() |
| 51 | * |
| 52 | * Get all user integer registers. |
| 53 | */ |
| 54 | static inline int ptrace_getregs(struct task_struct *task, void __user *uregs) |
| 55 | { |
| 56 | struct pt_regs *regs = task_pt_regs(task); |
| 57 | return copy_to_user(uregs, regs, sizeof(struct pt_regs)) ? -EFAULT : 0; |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * ptrace_get_reg() |
| 62 | * |
| 63 | * Get contents of register REGNO in task TASK. |
| 64 | */ |
| 65 | static unsigned long ptrace_get_reg(struct task_struct *task, int regno) |
| 66 | { |
| 67 | if (regno < sizeof(struct pt_regs)) { |
| 68 | struct pt_regs *pt_regs = task_pt_regs(task); |
| 69 | return *(unsigned long *)((long) pt_regs + regno); |
| 70 | } |
| 71 | |
| 72 | return -EIO; |
| 73 | } |
| 74 | |
| 75 | /* |
| 76 | * ptrace_put_reg() |
| 77 | * Write contents of register REGNO in task TASK. |
| 78 | */ |
| 79 | static int ptrace_put_reg(struct task_struct *task, int regno, |
| 80 | unsigned long data) |
| 81 | { |
| 82 | if (regno <= sizeof(struct pt_regs) && regno != PT_FRAME_TYPE) { |
| 83 | struct pt_regs *pt_regs = task_pt_regs(task); |
| 84 | *(unsigned long *)((long) pt_regs + regno) = data; |
| 85 | return 0; |
| 86 | } |
| 87 | return -EIO; |
| 88 | } |
| 89 | |
| 90 | /* |
| 91 | * ptrace_disable_single_step() |
| 92 | * Disable Single Step |
| 93 | */ |
| 94 | static int ptrace_disable_single_step(struct task_struct *task) |
| 95 | { |
| 96 | /* |
| 97 | * Single Step not yet implemented, so must always be disabled |
| 98 | */ |
| 99 | return 0; |
| 100 | } |
| 101 | |
| 102 | /* |
| 103 | * ptrace_disable() |
| 104 | * Make sure the single step bit is not set. |
| 105 | * Called by kernel/ptrace.c when detaching.. |
| 106 | */ |
| 107 | void ptrace_disable(struct task_struct *child) |
| 108 | { |
| 109 | ptrace_disable_single_step(child); |
| 110 | } |
| 111 | |
| 112 | /* |
| 113 | * arch_ptrace() |
| 114 | * architecture specific ptrace routine. |
| 115 | */ |
| 116 | long arch_ptrace(struct task_struct *child, long request, long addr, long data) |
| 117 | { |
| 118 | int ret; |
| 119 | switch (request) { |
| 120 | /* when I and D space are separate, these will need to be fixed. */ |
| 121 | case PTRACE_PEEKTEXT: /* read word at location addr. */ |
| 122 | case PTRACE_PEEKDATA: |
| 123 | ret = generic_ptrace_peekdata(child, addr, data); |
| 124 | break; |
| 125 | |
| 126 | /* read the word at location addr in the USER area. */ |
| 127 | case PTRACE_PEEKUSR: { |
| 128 | unsigned long tmp; |
| 129 | |
| 130 | ret = -EIO; |
| 131 | if (((unsigned long) addr > PT_INTERP_FDPIC_LOADMAP) |
| 132 | || (addr & 3)) |
| 133 | break; |
| 134 | |
| 135 | tmp = 0; /* Default return condition */ |
| 136 | |
| 137 | ret = -EIO; |
| 138 | if (addr < sizeof(struct pt_regs)) { |
| 139 | tmp = ptrace_get_reg(child, addr); |
| 140 | } else if (addr == PT_TEXT_ADDR) { |
| 141 | tmp = child->mm->start_code; |
| 142 | } else if (addr == PT_TEXT_END_ADDR) { |
| 143 | tmp = child->mm->end_code; |
| 144 | } else if (addr == PT_DATA_ADDR) { |
| 145 | tmp = child->mm->start_data; |
| 146 | } else if (addr == PT_EXEC_FDPIC_LOADMAP) { |
| 147 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
| 148 | tmp = child->mm->context.exec_fdpic_loadmap; |
| 149 | #endif |
| 150 | } else if (addr == PT_INTERP_FDPIC_LOADMAP) { |
| 151 | #ifdef CONFIG_BINFMT_ELF_FDPIC |
| 152 | tmp = child->mm->context.interp_fdpic_loadmap; |
| 153 | #endif |
| 154 | } else { |
| 155 | break; |
| 156 | } |
| 157 | |
| 158 | ret = put_user(tmp, (unsigned long *)data); |
| 159 | break; |
| 160 | } |
| 161 | |
| 162 | case PTRACE_POKETEXT: /* write the word at location addr. */ |
| 163 | case PTRACE_POKEDATA: |
| 164 | ret = generic_ptrace_pokedata(child, addr, data); |
| 165 | |
| 166 | /* |
| 167 | * If we just changed some code so we need to |
| 168 | * correct the caches |
| 169 | */ |
| 170 | if (request == PTRACE_POKETEXT && ret == 0) { |
| 171 | flush_icache_range(addr, addr + 4); |
| 172 | } |
| 173 | break; |
| 174 | |
| 175 | case PTRACE_POKEUSR: /* write the word at location addr |
| 176 | * in the USER area */ |
| 177 | ret = -EIO; |
| 178 | |
| 179 | if (((unsigned long) addr > PT_DATA_ADDR) || (addr & 3)) |
| 180 | break; |
| 181 | |
| 182 | if (addr < sizeof(struct pt_regs)) { |
| 183 | ret = ptrace_put_reg(child, addr, data); |
| 184 | } |
| 185 | break; |
| 186 | |
| 187 | case PTRACE_SYSCALL: /* continue and stop at next (return from) |
| 188 | * syscall */ |
| 189 | case PTRACE_CONT: { /* restart after signal. */ |
| 190 | |
| 191 | ret = -EIO; |
| 192 | if (!valid_signal(data)) |
| 193 | break; |
| 194 | if (request == PTRACE_SYSCALL) |
| 195 | set_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 196 | else |
| 197 | clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); |
| 198 | child->exit_code = data; |
| 199 | /* make sure the single step bit is not set. */ |
| 200 | ptrace_disable_single_step(child); |
| 201 | wake_up_process(child); |
| 202 | ret = 0; |
| 203 | break; |
| 204 | } |
| 205 | |
| 206 | /* |
| 207 | * make the child exit. Best I can do is send it a sigkill. |
| 208 | * perhaps it should be put in the status that it wants to exit. |
| 209 | */ |
| 210 | case PTRACE_KILL: { |
| 211 | ret = 0; |
| 212 | if (child->exit_state == EXIT_ZOMBIE) /* already dead */ |
| 213 | break; |
| 214 | child->exit_code = SIGKILL; |
| 215 | /* make sure the single step bit is not set. */ |
| 216 | ptrace_disable_single_step(child); |
| 217 | wake_up_process(child); |
| 218 | break; |
| 219 | } |
| 220 | |
| 221 | case PTRACE_DETACH: /* detach a process that was attached. */ |
| 222 | ret = ptrace_detach(child, data); |
| 223 | break; |
| 224 | |
| 225 | case PTRACE_GETREGS: /* Get all gp regs from the child. */ |
| 226 | ptrace_getregs(child, (unsigned long *)data); |
| 227 | ret = 0; |
| 228 | break; |
| 229 | |
| 230 | case PTRACE_SETREGS: { /* Set all gp regs in the child. */ |
| 231 | int i; |
| 232 | unsigned long tmp; |
| 233 | int count = sizeof(struct pt_regs) / sizeof(unsigned long); |
| 234 | for (i = 0; i < count; i++) { |
| 235 | if (get_user(tmp, (unsigned long *) data)) { |
| 236 | ret = -EFAULT; |
| 237 | break; |
| 238 | } |
| 239 | ptrace_put_reg(child, sizeof(unsigned long) * i, tmp); |
| 240 | data += sizeof(long); |
| 241 | } |
| 242 | ret = 0; |
| 243 | break; |
| 244 | } |
| 245 | |
| 246 | default: |
| 247 | return ptrace_request(child, request, addr, data); |
| 248 | break; |
| 249 | } |
| 250 | return ret; |
| 251 | } |
| 252 | /* |
| 253 | * syscall_trace |
| 254 | * |
| 255 | * called by syscall enter/exit when the TIF_SYSCALL_TRACE bit is set. |
| 256 | */ |
| 257 | asmlinkage void syscall_trace(void) |
| 258 | { |
| 259 | struct task_struct *cur = current; |
| 260 | if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| 261 | return; |
| 262 | if (!(cur->ptrace & PT_PTRACED)) |
| 263 | return; |
| 264 | ptrace_notify(SIGTRAP | ((cur->ptrace & PT_TRACESYSGOOD) |
| 265 | ? 0x80 : 0)); |
| 266 | /* |
| 267 | * this isn't the same as continuing with a signal, but it will do |
| 268 | * for normal use. strace only continues with a signal if the |
| 269 | * stopping signal is not SIGTRAP. -brl |
| 270 | */ |
| 271 | if (cur->exit_code) { |
| 272 | send_sig(cur->exit_code, current, 1); |
| 273 | current->exit_code = 0; |
| 274 | } |
| 275 | } |
| 276 | |
