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 <linux/kernel.h> 20 #include <linux/sched.h> 21 #include <linux/sched/task_stack.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/page.h> 34 #include <asm/pgtable.h> 35 36 /* 37 * Copy the thread state to a regset that can be interpreted by userspace. 38 * 39 * It doesn't matter what our internal pt_regs structure looks like. The 40 * important thing is that we export a consistent view of the thread state 41 * to userspace. As such, we need to make sure that the regset remains 42 * ABI compatible as defined by the struct user_regs_struct: 43 * 44 * (Each item is a 32-bit word) 45 * r0 = 0 (exported for clarity) 46 * 31 GPRS r1-r31 47 * PC (Program counter) 48 * SR (Supervision register) 49 */ 50 static int genregs_get(struct task_struct *target, 51 const struct user_regset *regset, 52 unsigned int pos, unsigned int count, 53 void *kbuf, void __user * ubuf) 54 { 55 const struct pt_regs *regs = task_pt_regs(target); 56 int ret; 57 58 /* r0 */ 59 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 0, 4); 60 61 if (!ret) 62 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 63 regs->gpr+1, 4, 4*32); 64 if (!ret) 65 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 66 ®s->pc, 4*32, 4*33); 67 if (!ret) 68 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 69 ®s->sr, 4*33, 4*34); 70 if (!ret) 71 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 72 4*34, -1); 73 74 return ret; 75 } 76 77 /* 78 * Set the thread state from a regset passed in via ptrace 79 */ 80 static int genregs_set(struct task_struct *target, 81 const struct user_regset *regset, 82 unsigned int pos, unsigned int count, 83 const void *kbuf, const void __user * ubuf) 84 { 85 struct pt_regs *regs = task_pt_regs(target); 86 int ret; 87 88 /* ignore r0 */ 89 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4); 90 /* r1 - r31 */ 91 if (!ret) 92 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 93 regs->gpr+1, 4, 4*32); 94 /* PC */ 95 if (!ret) 96 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 97 ®s->pc, 4*32, 4*33); 98 /* 99 * Skip SR and padding... userspace isn't allowed to changes bits in 100 * the Supervision register 101 */ 102 if (!ret) 103 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 104 4*33, -1); 105 106 return ret; 107 } 108 109 /* 110 * Define the register sets available on OpenRISC under Linux 111 */ 112 enum or1k_regset { 113 REGSET_GENERAL, 114 }; 115 116 static const struct user_regset or1k_regsets[] = { 117 [REGSET_GENERAL] = { 118 .core_note_type = NT_PRSTATUS, 119 .n = ELF_NGREG, 120 .size = sizeof(long), 121 .align = sizeof(long), 122 .get = genregs_get, 123 .set = genregs_set, 124 }, 125 }; 126 127 static const struct user_regset_view user_or1k_native_view = { 128 .name = "or1k", 129 .e_machine = EM_OPENRISC, 130 .regsets = or1k_regsets, 131 .n = ARRAY_SIZE(or1k_regsets), 132 }; 133 134 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 135 { 136 return &user_or1k_native_view; 137 } 138 139 /* 140 * does not yet catch signals sent when the child dies. 141 * in exit.c or in signal.c. 142 */ 143 144 145 /* 146 * Called by kernel/ptrace.c when detaching.. 147 * 148 * Make sure the single step bit is not set. 149 */ 150 void ptrace_disable(struct task_struct *child) 151 { 152 pr_debug("ptrace_disable(): TODO\n"); 153 154 user_disable_single_step(child); 155 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 156 } 157 158 long arch_ptrace(struct task_struct *child, long request, unsigned long addr, 159 unsigned long data) 160 { 161 int ret; 162 163 switch (request) { 164 default: 165 ret = ptrace_request(child, request, addr, data); 166 break; 167 } 168 169 return ret; 170 } 171 172 /* 173 * Notification of system call entry/exit 174 * - triggered by current->work.syscall_trace 175 */ 176 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 177 { 178 long ret = 0; 179 180 if (test_thread_flag(TIF_SYSCALL_TRACE) && 181 tracehook_report_syscall_entry(regs)) 182 /* 183 * Tracing decided this syscall should not happen. 184 * We'll return a bogus call number to get an ENOSYS 185 * error, but leave the original number in <something>. 186 */ 187 ret = -1L; 188 189 audit_syscall_entry(regs->gpr[11], regs->gpr[3], regs->gpr[4], 190 regs->gpr[5], regs->gpr[6]); 191 192 return ret ? : regs->gpr[11]; 193 } 194 195 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) 196 { 197 int step; 198 199 audit_syscall_exit(regs); 200 201 step = test_thread_flag(TIF_SINGLESTEP); 202 if (step || test_thread_flag(TIF_SYSCALL_TRACE)) 203 tracehook_report_syscall_exit(regs, step); 204 } 205