| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * linux/arch/unicore32/kernel/ptrace.c |
| * |
| * Code specific to PKUnity SoC and UniCore ISA |
| * |
| * Copyright (C) 2001-2010 GUAN Xue-tao |
| * |
| * By Ross Biro 1/23/92 |
| */ |
| #include <linux/kernel.h> |
| #include <linux/ptrace.h> |
| #include <linux/signal.h> |
| #include <linux/uaccess.h> |
| #include <linux/sched/task_stack.h> |
| |
| /* |
| * this routine will get a word off of the processes privileged stack. |
| * the offset is how far from the base addr as stored in the THREAD. |
| * this routine assumes that all the privileged stacks are in our |
| * data space. |
| */ |
| static inline long get_user_reg(struct task_struct *task, int offset) |
| { |
| return task_pt_regs(task)->uregs[offset]; |
| } |
| |
| /* |
| * this routine will put a word on the processes privileged stack. |
| * the offset is how far from the base addr as stored in the THREAD. |
| * this routine assumes that all the privileged stacks are in our |
| * data space. |
| */ |
| static inline int |
| put_user_reg(struct task_struct *task, int offset, long data) |
| { |
| struct pt_regs newregs, *regs = task_pt_regs(task); |
| int ret = -EINVAL; |
| |
| newregs = *regs; |
| newregs.uregs[offset] = data; |
| |
| if (valid_user_regs(&newregs)) { |
| regs->uregs[offset] = data; |
| ret = 0; |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * Called by kernel/ptrace.c when detaching.. |
| */ |
| void ptrace_disable(struct task_struct *child) |
| { |
| } |
| |
| /* |
| * We actually access the pt_regs stored on the kernel stack. |
| */ |
| static int ptrace_read_user(struct task_struct *tsk, unsigned long off, |
| unsigned long __user *ret) |
| { |
| unsigned long tmp; |
| |
| tmp = 0; |
| if (off < sizeof(struct pt_regs)) |
| tmp = get_user_reg(tsk, off >> 2); |
| |
| return put_user(tmp, ret); |
| } |
| |
| /* |
| * We actually access the pt_regs stored on the kernel stack. |
| */ |
| static int ptrace_write_user(struct task_struct *tsk, unsigned long off, |
| unsigned long val) |
| { |
| if (off >= sizeof(struct pt_regs)) |
| return 0; |
| |
| return put_user_reg(tsk, off >> 2, val); |
| } |
| |
| long arch_ptrace(struct task_struct *child, long request, |
| unsigned long addr, unsigned long data) |
| { |
| int ret; |
| unsigned long __user *datap = (unsigned long __user *) data; |
| |
| switch (request) { |
| case PTRACE_PEEKUSR: |
| ret = ptrace_read_user(child, addr, datap); |
| break; |
| |
| case PTRACE_POKEUSR: |
| ret = ptrace_write_user(child, addr, data); |
| break; |
| |
| case PTRACE_GET_THREAD_AREA: |
| ret = put_user(task_pt_regs(child)->UCreg_16, |
| datap); |
| break; |
| |
| default: |
| ret = ptrace_request(child, request, addr, data); |
| break; |
| } |
| |
| return ret; |
| } |
| |
| asmlinkage int syscall_trace(int why, struct pt_regs *regs, int scno) |
| { |
| unsigned long ip; |
| |
| if (!test_thread_flag(TIF_SYSCALL_TRACE)) |
| return scno; |
| if (!(current->ptrace & PT_PTRACED)) |
| return scno; |
| |
| /* |
| * Save IP. IP is used to denote syscall entry/exit: |
| * IP = 0 -> entry, = 1 -> exit |
| */ |
| ip = regs->UCreg_ip; |
| regs->UCreg_ip = why; |
| |
| current_thread_info()->syscall = scno; |
| |
| /* the 0x80 provides a way for the tracing parent to distinguish |
| between a syscall stop and SIGTRAP delivery */ |
| ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) |
| ? 0x80 : 0)); |
| /* |
| * this isn't the same as continuing with a signal, but it will do |
| * for normal use. strace only continues with a signal if the |
| * stopping signal is not SIGTRAP. -brl |
| */ |
| if (current->exit_code) { |
| send_sig(current->exit_code, current, 1); |
| current->exit_code = 0; |
| } |
| regs->UCreg_ip = ip; |
| |
| return current_thread_info()->syscall; |
| } |