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