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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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6dea1ba1c8
This patch adds ptrace support.
Changed from previous version:
1. disable arch_has_single_step and remove single-step instruction handler
2. add 'Ross Biro 1/23/92' contributor information
3. clean unused codes
Signed-off-by: Guan Xuetao <gxt@mprc.pku.edu.cn>
Acked-by: Arnd Bergmann <arnd@arndb.de>
149 lines
3.4 KiB
C
149 lines
3.4 KiB
C
/*
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* linux/arch/unicore32/kernel/ptrace.c
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*
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* Code specific to PKUnity SoC and UniCore ISA
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*
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* Copyright (C) 2001-2010 GUAN Xue-tao
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*
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* By Ross Biro 1/23/92
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/ptrace.h>
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#include <linux/signal.h>
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#include <linux/uaccess.h>
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/*
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* this routine will get a word off of the processes privileged stack.
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* the offset is how far from the base addr as stored in the THREAD.
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* this routine assumes that all the privileged stacks are in our
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* data space.
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*/
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static inline long get_user_reg(struct task_struct *task, int offset)
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{
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return task_pt_regs(task)->uregs[offset];
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}
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/*
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* this routine will put a word on the processes privileged stack.
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* the offset is how far from the base addr as stored in the THREAD.
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* this routine assumes that all the privileged stacks are in our
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* data space.
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*/
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static inline int
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put_user_reg(struct task_struct *task, int offset, long data)
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{
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struct pt_regs newregs, *regs = task_pt_regs(task);
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int ret = -EINVAL;
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newregs = *regs;
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newregs.uregs[offset] = data;
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if (valid_user_regs(&newregs)) {
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regs->uregs[offset] = data;
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ret = 0;
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}
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return ret;
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}
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/*
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* Called by kernel/ptrace.c when detaching..
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*/
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void ptrace_disable(struct task_struct *child)
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{
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}
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/*
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* We actually access the pt_regs stored on the kernel stack.
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*/
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static int ptrace_read_user(struct task_struct *tsk, unsigned long off,
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unsigned long __user *ret)
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{
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unsigned long tmp;
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tmp = 0;
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if (off < sizeof(struct pt_regs))
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tmp = get_user_reg(tsk, off >> 2);
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return put_user(tmp, ret);
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}
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/*
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* We actually access the pt_regs stored on the kernel stack.
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*/
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static int ptrace_write_user(struct task_struct *tsk, unsigned long off,
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unsigned long val)
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{
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if (off >= sizeof(struct pt_regs))
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return 0;
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return put_user_reg(tsk, off >> 2, val);
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}
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long arch_ptrace(struct task_struct *child, long request,
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unsigned long addr, unsigned long data)
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{
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int ret;
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unsigned long __user *datap = (unsigned long __user *) data;
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switch (request) {
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case PTRACE_PEEKUSR:
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ret = ptrace_read_user(child, addr, datap);
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break;
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case PTRACE_POKEUSR:
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ret = ptrace_write_user(child, addr, data);
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break;
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case PTRACE_GET_THREAD_AREA:
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ret = put_user(task_pt_regs(child)->UCreg_16,
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datap);
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break;
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default:
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ret = ptrace_request(child, request, addr, data);
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break;
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}
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return ret;
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}
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asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno)
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{
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unsigned long ip;
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if (!test_thread_flag(TIF_SYSCALL_TRACE))
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return scno;
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if (!(current->ptrace & PT_PTRACED))
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return scno;
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/*
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* Save IP. IP is used to denote syscall entry/exit:
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* IP = 0 -> entry, = 1 -> exit
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*/
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ip = regs->UCreg_ip;
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regs->UCreg_ip = why;
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current_thread_info()->syscall = scno;
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/* the 0x80 provides a way for the tracing parent to distinguish
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between a syscall stop and SIGTRAP delivery */
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ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
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? 0x80 : 0));
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/*
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* this isn't the same as continuing with a signal, but it will do
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* for normal use. strace only continues with a signal if the
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* stopping signal is not SIGTRAP. -brl
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*/
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if (current->exit_code) {
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send_sig(current->exit_code, current, 1);
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current->exit_code = 0;
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}
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regs->UCreg_ip = ip;
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return current_thread_info()->syscall;
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}
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