1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) 4 */ 5 6 #include <linux/audit.h> 7 #include <linux/ptrace.h> 8 #include <linux/sched.h> 9 #include <linux/uaccess.h> 10 #include <asm/ptrace-abi.h> 11 12 void user_enable_single_step(struct task_struct *child) 13 { 14 set_tsk_thread_flag(child, TIF_SINGLESTEP); 15 16 #ifdef SUBARCH_SET_SINGLESTEPPING 17 SUBARCH_SET_SINGLESTEPPING(child, 1); 18 #endif 19 } 20 21 void user_disable_single_step(struct task_struct *child) 22 { 23 clear_tsk_thread_flag(child, TIF_SINGLESTEP); 24 25 #ifdef SUBARCH_SET_SINGLESTEPPING 26 SUBARCH_SET_SINGLESTEPPING(child, 0); 27 #endif 28 } 29 30 /* 31 * Called by kernel/ptrace.c when detaching.. 32 */ 33 void ptrace_disable(struct task_struct *child) 34 { 35 user_disable_single_step(child); 36 } 37 38 extern int peek_user(struct task_struct * child, long addr, long data); 39 extern int poke_user(struct task_struct * child, long addr, long data); 40 41 long arch_ptrace(struct task_struct *child, long request, 42 unsigned long addr, unsigned long data) 43 { 44 int i, ret; 45 unsigned long __user *p = (void __user *)data; 46 void __user *vp = p; 47 48 switch (request) { 49 /* read the word at location addr in the USER area. */ 50 case PTRACE_PEEKUSR: 51 ret = peek_user(child, addr, data); 52 break; 53 54 /* write the word at location addr in the USER area */ 55 case PTRACE_POKEUSR: 56 ret = poke_user(child, addr, data); 57 break; 58 59 case PTRACE_SYSEMU: 60 case PTRACE_SYSEMU_SINGLESTEP: 61 ret = -EIO; 62 break; 63 64 #ifdef PTRACE_GETREGS 65 case PTRACE_GETREGS: { /* Get all gp regs from the child. */ 66 if (!access_ok(p, MAX_REG_OFFSET)) { 67 ret = -EIO; 68 break; 69 } 70 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 71 __put_user(getreg(child, i), p); 72 p++; 73 } 74 ret = 0; 75 break; 76 } 77 #endif 78 #ifdef PTRACE_SETREGS 79 case PTRACE_SETREGS: { /* Set all gp regs in the child. */ 80 unsigned long tmp = 0; 81 if (!access_ok(p, MAX_REG_OFFSET)) { 82 ret = -EIO; 83 break; 84 } 85 for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { 86 __get_user(tmp, p); 87 putreg(child, i, tmp); 88 p++; 89 } 90 ret = 0; 91 break; 92 } 93 #endif 94 case PTRACE_GET_THREAD_AREA: 95 ret = ptrace_get_thread_area(child, addr, vp); 96 break; 97 98 case PTRACE_SET_THREAD_AREA: 99 ret = ptrace_set_thread_area(child, addr, vp); 100 break; 101 102 default: 103 ret = ptrace_request(child, request, addr, data); 104 if (ret == -EIO) 105 ret = subarch_ptrace(child, request, addr, data); 106 break; 107 } 108 109 return ret; 110 } 111 112 static void send_sigtrap(struct uml_pt_regs *regs, int error_code) 113 { 114 /* Send us the fake SIGTRAP */ 115 force_sig_fault(SIGTRAP, TRAP_BRKPT, 116 /* User-mode eip? */ 117 UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL); 118 } 119 120 /* 121 * XXX Check TIF_SINGLESTEP for singlestepping check and 122 * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check 123 */ 124 int syscall_trace_enter(struct pt_regs *regs) 125 { 126 audit_syscall_entry(UPT_SYSCALL_NR(®s->regs), 127 UPT_SYSCALL_ARG1(®s->regs), 128 UPT_SYSCALL_ARG2(®s->regs), 129 UPT_SYSCALL_ARG3(®s->regs), 130 UPT_SYSCALL_ARG4(®s->regs)); 131 132 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 133 return 0; 134 135 return ptrace_report_syscall_entry(regs); 136 } 137 138 void syscall_trace_leave(struct pt_regs *regs) 139 { 140 int ptraced = current->ptrace; 141 142 audit_syscall_exit(regs); 143 144 /* Fake a debug trap */ 145 if (test_thread_flag(TIF_SINGLESTEP)) 146 send_sigtrap(®s->regs, 0); 147 148 if (!test_thread_flag(TIF_SYSCALL_TRACE)) 149 return; 150 151 ptrace_report_syscall_exit(regs, 0); 152 /* force do_signal() --> is_syscall() */ 153 if (ptraced & PT_PTRACED) 154 set_thread_flag(TIF_SIGPENDING); 155 } 156