1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * OpenRISC ptrace.c 4 * 5 * Linux architectural port borrowing liberally from similar works of 6 * others. All original copyrights apply as per the original source 7 * declaration. 8 * 9 * Modifications for the OpenRISC architecture: 10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com> 11 * Copyright (C) 2005 Gyorgy Jeney <nog@bsemi.com> 12 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se> 13 */ 14 15 #include <linux/kernel.h> 16 #include <linux/sched.h> 17 #include <linux/sched/task_stack.h> 18 #include <linux/string.h> 19 20 #include <linux/mm.h> 21 #include <linux/errno.h> 22 #include <linux/ptrace.h> 23 #include <linux/audit.h> 24 #include <linux/regset.h> 25 #include <linux/tracehook.h> 26 #include <linux/elf.h> 27 28 #include <asm/thread_info.h> 29 #include <asm/page.h> 30 31 /* 32 * Copy the thread state to a regset that can be interpreted by userspace. 33 * 34 * It doesn't matter what our internal pt_regs structure looks like. The 35 * important thing is that we export a consistent view of the thread state 36 * to userspace. As such, we need to make sure that the regset remains 37 * ABI compatible as defined by the struct user_regs_struct: 38 * 39 * (Each item is a 32-bit word) 40 * r0 = 0 (exported for clarity) 41 * 31 GPRS r1-r31 42 * PC (Program counter) 43 * SR (Supervision register) 44 */ 45 static int genregs_get(struct task_struct *target, 46 const struct user_regset *regset, 47 unsigned int pos, unsigned int count, 48 void *kbuf, void __user * ubuf) 49 { 50 const struct pt_regs *regs = task_pt_regs(target); 51 int ret; 52 53 /* r0 */ 54 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 0, 4); 55 56 if (!ret) 57 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 58 regs->gpr+1, 4, 4*32); 59 if (!ret) 60 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 61 ®s->pc, 4*32, 4*33); 62 if (!ret) 63 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, 64 ®s->sr, 4*33, 4*34); 65 if (!ret) 66 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, 67 4*34, -1); 68 69 return ret; 70 } 71 72 /* 73 * Set the thread state from a regset passed in via ptrace 74 */ 75 static int genregs_set(struct task_struct *target, 76 const struct user_regset *regset, 77 unsigned int pos, unsigned int count, 78 const void *kbuf, const void __user * ubuf) 79 { 80 struct pt_regs *regs = task_pt_regs(target); 81 int ret; 82 83 /* ignore r0 */ 84 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 0, 4); 85 /* r1 - r31 */ 86 if (!ret) 87 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 88 regs->gpr+1, 4, 4*32); 89 /* PC */ 90 if (!ret) 91 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, 92 ®s->pc, 4*32, 4*33); 93 /* 94 * Skip SR and padding... userspace isn't allowed to changes bits in 95 * the Supervision register 96 */ 97 if (!ret) 98 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, 99 4*33, -1); 100 101 return ret; 102 } 103 104 /* 105 * Define the register sets available on OpenRISC under Linux 106 */ 107 enum or1k_regset { 108 REGSET_GENERAL, 109 }; 110 111 static const struct user_regset or1k_regsets[] = { 112 [REGSET_GENERAL] = { 113 .core_note_type = NT_PRSTATUS, 114 .n = ELF_NGREG, 115 .size = sizeof(long), 116 .align = sizeof(long), 117 .get = genregs_get, 118 .set = genregs_set, 119 }, 120 }; 121 122 static const struct user_regset_view user_or1k_native_view = { 123 .name = "or1k", 124 .e_machine = EM_OPENRISC, 125 .regsets = or1k_regsets, 126 .n = ARRAY_SIZE(or1k_regsets), 127 }; 128 129 const struct user_regset_view *task_user_regset_view(struct task_struct *task) 130 { 131 return &user_or1k_native_view; 132 } 133 134 /* 135 * does not yet catch signals sent when the child dies. 136 * in exit.c or in signal.c. 137 */ 138 139 140 /* 141 * Called by kernel/ptrace.c when detaching.. 142 * 143 * Make sure the single step bit is not set. 144 */ 145 void ptrace_disable(struct task_struct *child) 146 { 147 pr_debug("ptrace_disable(): TODO\n"); 148 149 user_disable_single_step(child); 150 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE); 151 } 152 153 long arch_ptrace(struct task_struct *child, long request, unsigned long addr, 154 unsigned long data) 155 { 156 int ret; 157 158 switch (request) { 159 default: 160 ret = ptrace_request(child, request, addr, data); 161 break; 162 } 163 164 return ret; 165 } 166 167 /* 168 * Notification of system call entry/exit 169 * - triggered by current->work.syscall_trace 170 */ 171 asmlinkage long do_syscall_trace_enter(struct pt_regs *regs) 172 { 173 long ret = 0; 174 175 if (test_thread_flag(TIF_SYSCALL_TRACE) && 176 tracehook_report_syscall_entry(regs)) 177 /* 178 * Tracing decided this syscall should not happen. 179 * We'll return a bogus call number to get an ENOSYS 180 * error, but leave the original number in <something>. 181 */ 182 ret = -1L; 183 184 audit_syscall_entry(regs->gpr[11], regs->gpr[3], regs->gpr[4], 185 regs->gpr[5], regs->gpr[6]); 186 187 return ret ? : regs->gpr[11]; 188 } 189 190 asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) 191 { 192 int step; 193 194 audit_syscall_exit(regs); 195 196 step = test_thread_flag(TIF_SINGLESTEP); 197 if (step || test_thread_flag(TIF_SYSCALL_TRACE)) 198 tracehook_report_syscall_exit(regs, step); 199 } 200