1/* 2 * Copyright 2010 Tilera Corporation. All Rights Reserved. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License 6 * as published by the Free Software Foundation, version 2. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or 11 * NON INFRINGEMENT. See the GNU General Public License for 12 * more details. 13 * 14 * Copied from i386: Ross Biro 1/23/92 15 */ 16 17#include <linux/kernel.h> 18#include <linux/ptrace.h> 19#include <linux/kprobes.h> 20#include <linux/compat.h> 21#include <linux/uaccess.h> 22#include <asm/traps.h> 23 24void user_enable_single_step(struct task_struct *child) 25{ 26 set_tsk_thread_flag(child, TIF_SINGLESTEP); 27} 28 29void user_disable_single_step(struct task_struct *child) 30{ 31 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 32} 33 34/* 35 * This routine will put a word on the process's privileged stack. 36 */ 37static void putreg(struct task_struct *task, 38 unsigned long addr, unsigned long value) 39{ 40 unsigned int regno = addr / sizeof(unsigned long); 41 struct pt_regs *childregs = task_pt_regs(task); 42 childregs->regs[regno] = value; 43 childregs->flags |= PT_FLAGS_RESTORE_REGS; 44} 45 46static unsigned long getreg(struct task_struct *task, unsigned long addr) 47{ 48 unsigned int regno = addr / sizeof(unsigned long); 49 struct pt_regs *childregs = task_pt_regs(task); 50 return childregs->regs[regno]; 51} 52 53/* 54 * Called by kernel/ptrace.c when detaching.. 55 */ 56void ptrace_disable(struct task_struct *child) 57{ 58 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 59 60 /* 61 * These two are currently unused, but will be set by arch_ptrace() 62 * and used in the syscall assembly when we do support them. 63 */ 64 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 65} 66 67long arch_ptrace(struct task_struct *child, long request, long addr, long data) 68{ 69 unsigned long __user *datap; 70 unsigned long tmp; 71 int i; 72 long ret = -EIO; 73 74#ifdef CONFIG_COMPAT 75 if (task_thread_info(current)->status & TS_COMPAT) 76 data = (u32)data; 77 if (task_thread_info(child)->status & TS_COMPAT) 78 addr = (u32)addr; 79#endif 80 datap = (unsigned long __user __force *)data; 81 82 switch (request) { 83 84 case PTRACE_PEEKUSR: /* Read register from pt_regs. */ 85 if (addr & (sizeof(data)-1)) 86 break; 87 if (addr < 0 || addr >= PTREGS_SIZE) 88 break; 89 tmp = getreg(child, addr); /* Read register */ 90 ret = put_user(tmp, datap); 91 break; 92 93 case PTRACE_POKEUSR: /* Write register in pt_regs. */ 94 if (addr & (sizeof(data)-1)) 95 break; 96 if (addr < 0 || addr >= PTREGS_SIZE) 97 break; 98 putreg(child, addr, data); /* Write register */ 99 ret = 0; 100 break; 101 102 case PTRACE_GETREGS: /* Get all registers from the child. */ 103 if (!access_ok(VERIFY_WRITE, datap, PTREGS_SIZE)) 104 break; 105 for (i = 0; i < PTREGS_SIZE; i += sizeof(long)) { 106 ret = __put_user(getreg(child, i), datap); 107 if (ret != 0) 108 break; 109 datap++; 110 } 111 break; 112 113 case PTRACE_SETREGS: /* Set all registers in the child. */ 114 if (!access_ok(VERIFY_READ, datap, PTREGS_SIZE)) 115 break; 116 for (i = 0; i < PTREGS_SIZE; i += sizeof(long)) { 117 ret = __get_user(tmp, datap); 118 if (ret != 0) 119 break; 120 putreg(child, i, tmp); 121 datap++; 122 } 123 break; 124 125 case PTRACE_GETFPREGS: /* Get the child FPU state. */ 126 case PTRACE_SETFPREGS: /* Set the child FPU state. */ 127 break; 128 129 case PTRACE_SETOPTIONS: 130 /* Support TILE-specific ptrace options. */ 131 child->ptrace &= ~PT_TRACE_MASK_TILE; 132 tmp = data & PTRACE_O_MASK_TILE; 133 data &= ~PTRACE_O_MASK_TILE; 134 ret = ptrace_request(child, request, addr, data); 135 if (tmp & PTRACE_O_TRACEMIGRATE) 136 child->ptrace |= PT_TRACE_MIGRATE; 137 break; 138 139 default: 140#ifdef CONFIG_COMPAT 141 if (task_thread_info(current)->status & TS_COMPAT) { 142 ret = compat_ptrace_request(child, request, 143 addr, data); 144 break; 145 } 146#endif 147 ret = ptrace_request(child, request, addr, data); 148 break; 149 } 150 151 return ret; 152} 153 154#ifdef CONFIG_COMPAT 155/* Not used; we handle compat issues in arch_ptrace() directly. */ 156long compat_arch_ptrace(struct task_struct *child, compat_long_t request, 157 compat_ulong_t addr, compat_ulong_t data) 158{ 159 BUG(); 160} 161#endif 162 163void do_syscall_trace(void) 164{ 165 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 166 return; 167 168 if (!(current->ptrace & PT_PTRACED)) 169 return; 170 171 /* 172 * The 0x80 provides a way for the tracing parent to distinguish 173 * between a syscall stop and SIGTRAP delivery 174 */ 175 ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0)); 176 177 /* 178 * this isn't the same as continuing with a signal, but it will do 179 * for normal use. strace only continues with a signal if the 180 * stopping signal is not SIGTRAP. -brl 181 */ 182 if (current->exit_code) { 183 send_sig(current->exit_code, current, 1); 184 current->exit_code = 0; 185 } 186} 187 188void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code) 189{ 190 struct siginfo info; 191 192 memset(&info, 0, sizeof(info)); 193 info.si_signo = SIGTRAP; 194 info.si_code = TRAP_BRKPT; 195 info.si_addr = (void __user *) regs->pc; 196 197 /* Send us the fakey SIGTRAP */ 198 force_sig_info(SIGTRAP, &info, tsk); 199} 200 201/* Handle synthetic interrupt delivered only by the simulator. */ 202void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num) 203{ 204 send_sigtrap(current, regs, fault_num); 205} 206