1 /* 2 * OpenRISC ptrace.c 3 * 4 * Linux architectural port borrowing liberally from similar works of 5 * others. All original copyrights apply as per the original source 6 * declaration. 7 * 8 * Modifications for the OpenRISC architecture: 9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 10 * Copyright (C) 2005 Gyorgy Jeney <nog@bsemi.com> 11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 12 * 13 * This program is free software; you can redistribute it and/or 14 * modify it under the terms of the GNU General Public License 15 * as published by the Free Software Foundation; either version 16 * 2 of the License, or (at your option) any later version. 17 */ 18 19 #include <stddef.h> 20 #include <linux/kernel.h> 21 #include <linux/sched.h> 22 #include <linux/string.h> 23 24 #include <linux/mm.h> 25 #include <linux/errno.h> 26 #include <linux/ptrace.h> 27 #include <linux/audit.h> 28 #include <linux/regset.h> 29 #include <linux/tracehook.h> 30 #include <linux/elf.h> 31 32 #include <asm/thread_info.h> 33 #include <asm/segment.h> 34 #include <asm/page.h> 35 #include <asm/pgtable.h> 36 #include <asm/system.h> 37 38 /* 39 * Copy the thread state to a regset that can be interpreted by userspace. 40 * 41 * It doesn't matter what our internal pt_regs structure looks like. The 42 * important thing is that we export a consistent view of the thread state 43 * to userspace. As such, we need to make sure that the regset remains 44 * ABI compatible as defined by the struct user_regs_struct: 45 * 46 * (Each item is a 32-bit word) 47 * r0 = 0 (exported for clarity) 48 * 31 GPRS r1-r31 49 * PC (Program counter) 50 * SR (Supervision register) 51 */ 52 static int genregs_get(struct task_struct *target, 53 const struct user_regset *regset, 54 unsigned int pos, unsigned int count, 55 void *kbuf, void __user * ubuf) 56 { 57 const struct pt_regs *regs = task_pt_regs(target); 58 int ret; 59 60 /* r0 */ 61 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 0, 4); 62 63 if (!ret) 64 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 65 regs->gpr+1, 4, 4*32); 66 if (!ret) 67 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 68 ®s->pc, 4*32, 4*33); 69 if (!ret) 70 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 71 ®s->sr, 4*33, 4*34); 72 if (!ret) 73 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 74 4*34, -1); 75 76 return ret; 77 } 78 79 /* 80 * Set the thread state from a regset passed in via ptrace 81 */ 82 static int genregs_set(struct task_struct *target, 83 const struct user_regset *regset, 84 unsigned int pos, unsigned int count, 85 const void *kbuf, const void __user * ubuf) 86 { 87 struct pt_regs *regs = task_pt_regs(target); 88 int ret; 89 90 /* ignore r0 */ 91 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4); 92 /* r1 - r31 */ 93 if (!ret) 94 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 95 regs->gpr+1, 4, 4*32); 96 /* PC */ 97 if (!ret) 98 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 99 ®s->pc, 4*32, 4*33); 100 /* 101 * Skip SR and padding... userspace isn't allowed to changes bits in 102 * the Supervision register 103 */ 104 if (!ret) 105 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 106 4*33, -1); 107 108 return ret; 109 } 110 111 /* 112 * Define the register sets available on OpenRISC under Linux 113 */ 114 enum or1k_regset { 115 REGSET_GENERAL, 116 }; 117 118 static const struct user_regset or1k_regsets[] = { 119 [REGSET_GENERAL] = { 120 .core_note_type = NT_PRSTATUS, 121 .n = ELF_NGREG, 122 .size = sizeof(long), 123 .align = sizeof(long), 124 .get = genregs_get, 125 .set = genregs_set, 126 }, 127 }; 128 129 static const struct user_regset_view user_or1k_native_view = { 130 .name = "or1k", 131 .e_machine = EM_OPENRISC, 132 .regsets = or1k_regsets, 133 .n = ARRAY_SIZE(or1k_regsets), 134 }; 135 136 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 137 { 138 return &user_or1k_native_view; 139 } 140 141 /* 142 * does not yet catch signals sent when the child dies. 143 * in exit.c or in signal.c. 144 */ 145 146 147 /* 148 * Called by kernel/ptrace.c when detaching.. 149 * 150 * Make sure the single step bit is not set. 151 */ 152 void ptrace_disable(struct task_struct *child) 153 { 154 pr_debug("ptrace_disable(): TODO\n"); 155 156 user_disable_single_step(child); 157 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 158 } 159 160 long arch_ptrace(struct task_struct *child, long request, unsigned long addr, 161 unsigned long data) 162 { 163 int ret; 164 165 switch (request) { 166 default: 167 ret = ptrace_request(child, request, addr, data); 168 break; 169 } 170 171 return ret; 172 } 173 174 /* 175 * Notification of system call entry/exit 176 * - triggered by current->work.syscall_trace 177 */ 178 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 179 { 180 long ret = 0; 181 182 if (test_thread_flag(TIF_SYSCALL_TRACE) && 183 tracehook_report_syscall_entry(regs)) 184 /* 185 * Tracing decided this syscall should not happen. 186 * We'll return a bogus call number to get an ENOSYS 187 * error, but leave the original number in <something>. 188 */ 189 ret = -1L; 190 191 /* Are these regs right??? */ 192 if (unlikely(current->audit_context)) 193 audit_syscall_entry(audit_arch(), regs->syscallno, 194 regs->gpr[3], regs->gpr[4], 195 regs->gpr[5], regs->gpr[6]); 196 197 return ret ? : regs->syscallno; 198 } 199 200 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) 201 { 202 int step; 203 204 if (unlikely(current->audit_context)) 205 audit_syscall_exit(AUDITSC_RESULT(regs->gpr[11]), 206 regs->gpr[11]); 207 208 step = test_thread_flag(TIF_SINGLESTEP); 209 if (step || test_thread_flag(TIF_SYSCALL_TRACE)) 210 tracehook_report_syscall_exit(regs, step); 211 } 212