170 lines
4.6 KiB
C
170 lines
4.6 KiB
C
/*
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* `ptrace' system call
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*
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* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2007-2009 PetaLogix
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* Copyright (C) 2004-2007 John Williams <john.williams@petalogix.com>
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*
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* derived from arch/v850/kernel/ptrace.c
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*
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* Copyright (C) 2002,03 NEC Electronics Corporation
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* Copyright (C) 2002,03 Miles Bader <miles@gnu.org>
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*
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* Derived from arch/mips/kernel/ptrace.c:
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*
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* Copyright (C) 1992 Ross Biro
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* Copyright (C) Linus Torvalds
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* Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
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* Copyright (C) 1996 David S. Miller
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* Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
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* Copyright (C) 1999 MIPS Technologies, Inc.
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file COPYING in the main directory of this
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* archive for more details.
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*/
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/sched/task_stack.h>
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#include <linux/ptrace.h>
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#include <linux/signal.h>
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#include <linux/elf.h>
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#include <linux/audit.h>
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#include <linux/seccomp.h>
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#include <linux/errno.h>
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#include <asm/processor.h>
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#include <linux/uaccess.h>
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#include <asm/asm-offsets.h>
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#include <asm/cacheflush.h>
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#include <asm/syscall.h>
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#include <linux/io.h>
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/* Returns the address where the register at REG_OFFS in P is stashed away. */
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static microblaze_reg_t *reg_save_addr(unsigned reg_offs,
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struct task_struct *t)
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{
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struct pt_regs *regs;
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/*
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* Three basic cases:
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*
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* (1) A register normally saved before calling the scheduler, is
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* available in the kernel entry pt_regs structure at the top
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* of the kernel stack. The kernel trap/irq exit path takes
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* care to save/restore almost all registers for ptrace'd
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* processes.
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*
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* (2) A call-clobbered register, where the process P entered the
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* kernel via [syscall] trap, is not stored anywhere; that's
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* OK, because such registers are not expected to be preserved
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* when the trap returns anyway (so we don't actually bother to
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* test for this case).
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*
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* (3) A few registers not used at all by the kernel, and so
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* normally never saved except by context-switches, are in the
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* context switch state.
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*/
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/* Register saved during kernel entry (or not available). */
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regs = task_pt_regs(t);
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return (microblaze_reg_t *)((char *)regs + reg_offs);
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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 rval;
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unsigned long val = 0;
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switch (request) {
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/* Read/write the word at location ADDR in the registers. */
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case PTRACE_PEEKUSR:
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case PTRACE_POKEUSR:
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pr_debug("PEEKUSR/POKEUSR : 0x%08lx\n", addr);
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rval = 0;
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if (addr >= PT_SIZE && request == PTRACE_PEEKUSR) {
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/*
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* Special requests that don't actually correspond
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* to offsets in struct pt_regs.
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*/
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if (addr == PT_TEXT_ADDR) {
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val = child->mm->start_code;
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} else if (addr == PT_DATA_ADDR) {
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val = child->mm->start_data;
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} else if (addr == PT_TEXT_LEN) {
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val = child->mm->end_code
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- child->mm->start_code;
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} else {
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rval = -EIO;
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}
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} else if (addr < PT_SIZE && (addr & 0x3) == 0) {
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microblaze_reg_t *reg_addr = reg_save_addr(addr, child);
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if (request == PTRACE_PEEKUSR)
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val = *reg_addr;
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else {
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#if 1
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*reg_addr = data;
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#else
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/* MS potential problem on WB system
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* Be aware that reg_addr is virtual address
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* virt_to_phys conversion is necessary.
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* This could be sensible solution.
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*/
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u32 paddr = virt_to_phys((u32)reg_addr);
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invalidate_icache_range(paddr, paddr + 4);
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*reg_addr = data;
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flush_dcache_range(paddr, paddr + 4);
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#endif
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}
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} else
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rval = -EIO;
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if (rval == 0 && request == PTRACE_PEEKUSR)
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rval = put_user(val, (unsigned long __user *)data);
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break;
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default:
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rval = ptrace_request(child, request, addr, data);
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}
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return rval;
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}
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asmlinkage unsigned long do_syscall_trace_enter(struct pt_regs *regs)
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{
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unsigned long ret = 0;
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secure_computing_strict(regs->r12);
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if (test_thread_flag(TIF_SYSCALL_TRACE) &&
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ptrace_report_syscall_entry(regs))
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/*
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* Tracing decided this syscall should not happen.
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* We'll return a bogus call number to get an ENOSYS
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* error, but leave the original number in regs->regs[0].
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*/
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ret = -1L;
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audit_syscall_entry(regs->r12, regs->r5, regs->r6, regs->r7, regs->r8);
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return ret ?: regs->r12;
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}
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asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
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{
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int step;
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audit_syscall_exit(regs);
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step = test_thread_flag(TIF_SINGLESTEP);
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if (step || test_thread_flag(TIF_SYSCALL_TRACE))
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ptrace_report_syscall_exit(regs, step);
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}
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void ptrace_disable(struct task_struct *child)
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{
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/* nothing to do */
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}
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