| /* |
| * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com) |
| * Licensed under the GPL |
| */ |
| |
| #include <linux/audit.h> |
| #include <linux/ptrace.h> |
| #include <linux/sched.h> |
| #include <linux/tracehook.h> |
| #include <linux/uaccess.h> |
| #include <asm/ptrace-abi.h> |
| |
| void user_enable_single_step(struct task_struct *child) |
| { |
| child->ptrace |= PT_DTRACE; |
| child->thread.singlestep_syscall = 0; |
| |
| #ifdef SUBARCH_SET_SINGLESTEPPING |
| SUBARCH_SET_SINGLESTEPPING(child, 1); |
| #endif |
| } |
| |
| void user_disable_single_step(struct task_struct *child) |
| { |
| child->ptrace &= ~PT_DTRACE; |
| child->thread.singlestep_syscall = 0; |
| |
| #ifdef SUBARCH_SET_SINGLESTEPPING |
| SUBARCH_SET_SINGLESTEPPING(child, 0); |
| #endif |
| } |
| |
| /* |
| * Called by kernel/ptrace.c when detaching.. |
| */ |
| void ptrace_disable(struct task_struct *child) |
| { |
| user_disable_single_step(child); |
| } |
| |
| extern int peek_user(struct task_struct * child, long addr, long data); |
| extern int poke_user(struct task_struct * child, long addr, long data); |
| |
| long arch_ptrace(struct task_struct *child, long request, |
| unsigned long addr, unsigned long data) |
| { |
| int i, ret; |
| unsigned long __user *p = (void __user *)data; |
| void __user *vp = p; |
| |
| switch (request) { |
| /* read the word at location addr in the USER area. */ |
| case PTRACE_PEEKUSR: |
| ret = peek_user(child, addr, data); |
| break; |
| |
| /* write the word at location addr in the USER area */ |
| case PTRACE_POKEUSR: |
| ret = poke_user(child, addr, data); |
| break; |
| |
| case PTRACE_SYSEMU: |
| case PTRACE_SYSEMU_SINGLESTEP: |
| ret = -EIO; |
| break; |
| |
| #ifdef PTRACE_GETREGS |
| case PTRACE_GETREGS: { /* Get all gp regs from the child. */ |
| if (!access_ok(p, MAX_REG_OFFSET)) { |
| ret = -EIO; |
| break; |
| } |
| for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { |
| __put_user(getreg(child, i), p); |
| p++; |
| } |
| ret = 0; |
| break; |
| } |
| #endif |
| #ifdef PTRACE_SETREGS |
| case PTRACE_SETREGS: { /* Set all gp regs in the child. */ |
| unsigned long tmp = 0; |
| if (!access_ok(p, MAX_REG_OFFSET)) { |
| ret = -EIO; |
| break; |
| } |
| for ( i = 0; i < MAX_REG_OFFSET; i += sizeof(long) ) { |
| __get_user(tmp, p); |
| putreg(child, i, tmp); |
| p++; |
| } |
| ret = 0; |
| break; |
| } |
| #endif |
| case PTRACE_GET_THREAD_AREA: |
| ret = ptrace_get_thread_area(child, addr, vp); |
| break; |
| |
| case PTRACE_SET_THREAD_AREA: |
| ret = ptrace_set_thread_area(child, addr, vp); |
| break; |
| |
| default: |
| ret = ptrace_request(child, request, addr, data); |
| if (ret == -EIO) |
| ret = subarch_ptrace(child, request, addr, data); |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static void send_sigtrap(struct uml_pt_regs *regs, int error_code) |
| { |
| /* Send us the fake SIGTRAP */ |
| force_sig_fault(SIGTRAP, TRAP_BRKPT, |
| /* User-mode eip? */ |
| UPT_IS_USER(regs) ? (void __user *) UPT_IP(regs) : NULL); |
| } |
| |
| /* |
| * XXX Check PT_DTRACE vs TIF_SINGLESTEP for singlestepping check and |
| * PT_PTRACED vs TIF_SYSCALL_TRACE for syscall tracing check |
| */ |
| int syscall_trace_enter(struct pt_regs *regs) |
| { |
| audit_syscall_entry(UPT_SYSCALL_NR(®s->regs), |
| UPT_SYSCALL_ARG1(®s->regs), |
| UPT_SYSCALL_ARG2(®s->regs), |
| UPT_SYSCALL_ARG3(®s->regs), |
| UPT_SYSCALL_ARG4(®s->regs)); |
| |
| if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| return 0; |
| |
| return tracehook_report_syscall_entry(regs); |
| } |
| |
| void syscall_trace_leave(struct pt_regs *regs) |
| { |
| int ptraced = current->ptrace; |
| |
| audit_syscall_exit(regs); |
| |
| /* Fake a debug trap */ |
| if (ptraced & PT_DTRACE) |
| send_sigtrap(®s->regs, 0); |
| |
| if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| return; |
| |
| tracehook_report_syscall_exit(regs, 0); |
| /* force do_signal() --> is_syscall() */ |
| if (ptraced & PT_PTRACED) |
| set_thread_flag(TIF_SIGPENDING); |
| } |