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