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/segment.h> 34 #include <asm/page.h> 35 #include <asm/pgtable.h> 36 37 /* 38 * Copy the thread state to a regset that can be interpreted by userspace. 39 * 40 * It doesn't matter what our internal pt_regs structure looks like. The 41 * important thing is that we export a consistent view of the thread state 42 * to userspace. As such, we need to make sure that the regset remains 43 * ABI compatible as defined by the struct user_regs_struct: 44 * 45 * (Each item is a 32-bit word) 46 * r0 = 0 (exported for clarity) 47 * 31 GPRS r1-r31 48 * PC (Program counter) 49 * SR (Supervision register) 50 */ 51 static int genregs_get(struct task_struct *target, 52 const struct user_regset *regset, 53 unsigned int pos, unsigned int count, 54 void *kbuf, void __user * ubuf) 55 { 56 const struct pt_regs *regs = task_pt_regs(target); 57 int ret; 58 59 /* r0 */ 60 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 0, 4); 61 62 if (!ret) 63 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 64 regs->gpr+1, 4, 4*32); 65 if (!ret) 66 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 67 ®s->pc, 4*32, 4*33); 68 if (!ret) 69 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 70 ®s->sr, 4*33, 4*34); 71 if (!ret) 72 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 73 4*34, -1); 74 75 return ret; 76 } 77 78 /* 79 * Set the thread state from a regset passed in via ptrace 80 */ 81 static int genregs_set(struct task_struct *target, 82 const struct user_regset *regset, 83 unsigned int pos, unsigned int count, 84 const void *kbuf, const void __user * ubuf) 85 { 86 struct pt_regs *regs = task_pt_regs(target); 87 int ret; 88 89 /* ignore r0 */ 90 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4); 91 /* r1 - r31 */ 92 if (!ret) 93 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 94 regs->gpr+1, 4, 4*32); 95 /* PC */ 96 if (!ret) 97 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 98 ®s->pc, 4*32, 4*33); 99 /* 100 * Skip SR and padding... userspace isn't allowed to changes bits in 101 * the Supervision register 102 */ 103 if (!ret) 104 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 105 4*33, -1); 106 107 return ret; 108 } 109 110 /* 111 * Define the register sets available on OpenRISC under Linux 112 */ 113 enum or1k_regset { 114 REGSET_GENERAL, 115 }; 116 117 static const struct user_regset or1k_regsets[] = { 118 [REGSET_GENERAL] = { 119 .core_note_type = NT_PRSTATUS, 120 .n = ELF_NGREG, 121 .size = sizeof(long), 122 .align = sizeof(long), 123 .get = genregs_get, 124 .set = genregs_set, 125 }, 126 }; 127 128 static const struct user_regset_view user_or1k_native_view = { 129 .name = "or1k", 130 .e_machine = EM_OPENRISC, 131 .regsets = or1k_regsets, 132 .n = ARRAY_SIZE(or1k_regsets), 133 }; 134 135 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 136 { 137 return &user_or1k_native_view; 138 } 139 140 /* 141 * does not yet catch signals sent when the child dies. 142 * in exit.c or in signal.c. 143 */ 144 145 146 /* 147 * Called by kernel/ptrace.c when detaching.. 148 * 149 * Make sure the single step bit is not set. 150 */ 151 void ptrace_disable(struct task_struct *child) 152 { 153 pr_debug("ptrace_disable(): TODO\n"); 154 155 user_disable_single_step(child); 156 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 157 } 158 159 long arch_ptrace(struct task_struct *child, long request, unsigned long addr, 160 unsigned long data) 161 { 162 int ret; 163 164 switch (request) { 165 default: 166 ret = ptrace_request(child, request, addr, data); 167 break; 168 } 169 170 return ret; 171 } 172 173 /* 174 * Notification of system call entry/exit 175 * - triggered by current->work.syscall_trace 176 */ 177 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 178 { 179 long ret = 0; 180 181 if (test_thread_flag(TIF_SYSCALL_TRACE) && 182 tracehook_report_syscall_entry(regs)) 183 /* 184 * Tracing decided this syscall should not happen. 185 * We'll return a bogus call number to get an ENOSYS 186 * error, but leave the original number in <something>. 187 */ 188 ret = -1L; 189 190 audit_syscall_entry(regs->gpr[11], regs->gpr[3], regs->gpr[4], 191 regs->gpr[5], regs->gpr[6]); 192 193 return ret ? : regs->gpr[11]; 194 } 195 196 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) 197 { 198 int step; 199 200 audit_syscall_exit(regs); 201 202 step = test_thread_flag(TIF_SINGLESTEP); 203 if (step || test_thread_flag(TIF_SYSCALL_TRACE)) 204 tracehook_report_syscall_exit(regs, step); 205 } 206