| 1 | |
| 2 | * `ptrace' system call
|
| 3 | *
|
| 4 | * Copyright (C) 2008-2009 Michal Simek <[email protected]>
|
| 5 | * Copyright (C) 2007-2009 PetaLogix
|
| 6 | * Copyright (C) 2004-2007 John Williams <[email protected]>
|
| 7 | *
|
| 8 | * derived from arch/v850/kernel/ptrace.c
|
| 9 | *
|
| 10 | * Copyright (C) 2002,03 NEC Electronics Corporation
|
| 11 | * Copyright (C) 2002,03 Miles Bader <[email protected]>
|
| 12 | *
|
| 13 | * Derived from arch/mips/kernel/ptrace.c:
|
| 14 | *
|
| 15 | * Copyright (C) 1992 Ross Biro
|
| 16 | * Copyright (C) Linus Torvalds
|
| 17 | * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
|
| 18 | * Copyright (C) 1996 David S. Miller
|
| 19 | * Kevin D. Kissell, [email protected] and Carsten Langgaard, [email protected]
|
| 20 | * Copyright (C) 1999 MIPS Technologies, Inc.
|
| 21 | *
|
| 22 | * This file is subject to the terms and conditions of the GNU General
|
| 23 | * Public License. See the file COPYING in the main directory of this
|
| 24 | * archive for more details.
|
| 25 |
|
| 26 |
|
| 27 | #include <linux/kernel.h>
|
| 28 | #include <linux/mm.h>
|
| 29 | #include <linux/sched.h>
|
| 30 | #include <linux/sched/task_stack.h>
|
| 31 | #include <linux/ptrace.h>
|
| 32 | #include <linux/signal.h>
|
| 33 | #include <linux/elf.h>
|
| 34 | #include <linux/audit.h>
|
| 35 | #include <linux/seccomp.h>
|
| 36 |
|
| 37 | #include <linux/errno.h>
|
| 38 | #include <asm/processor.h>
|
| 39 | #include <linux/uaccess.h>
|
| 40 | #include <asm/asm-offsets.h>
|
| 41 | #include <asm/cacheflush.h>
|
| 42 | #include <asm/syscall.h>
|
| 43 | #include <linux/io.h>
|
| 44 |
|
| 45 |
|
| 46 | static microblaze_reg_t *reg_save_addr(unsigned reg_offs,
|
| 47 | struct task_struct *t)
|
| 48 | {
|
| 49 | struct pt_regs *regs;
|
| 50 |
|
| 51 | |
| 52 | * Three basic cases:
|
| 53 | *
|
| 54 | * (1) A register normally saved before calling the scheduler, is
|
| 55 | * available in the kernel entry pt_regs structure at the top
|
| 56 | * of the kernel stack. The kernel trap/irq exit path takes
|
| 57 | * care to save/restore almost all registers for ptrace'd
|
| 58 | * processes.
|
| 59 | *
|
| 60 | * (2) A call-clobbered register, where the process P entered the
|
| 61 | * kernel via [syscall] trap, is not stored anywhere; that's
|
| 62 | * OK, because such registers are not expected to be preserved
|
| 63 | * when the trap returns anyway (so we don't actually bother to
|
| 64 | * test for this case).
|
| 65 | *
|
| 66 | * (3) A few registers not used at all by the kernel, and so
|
| 67 | * normally never saved except by context-switches, are in the
|
| 68 | * context switch state.
|
| 69 |
|
| 70 |
|
| 71 |
|
| 72 | regs = task_pt_regs(t);
|
| 73 |
|
| 74 | return (microblaze_reg_t *)((char *)regs + reg_offs);
|
| 75 | }
|
| 76 |
|
| 77 | long arch_ptrace(struct task_struct *child, long request,
|
| 78 | unsigned long addr, unsigned long data)
|
| 79 | {
|
| 80 | int rval;
|
| 81 | unsigned long val = 0;
|
| 82 |
|
| 83 | switch (request) {
|
| 84 |
|
| 85 | case PTRACE_PEEKUSR:
|
| 86 | case PTRACE_POKEUSR:
|
| 87 | pr_debug("PEEKUSR/POKEUSR : 0x%08lx\n", addr);
|
| 88 | rval = 0;
|
| 89 | if (addr >= PT_SIZE && request == PTRACE_PEEKUSR) {
|
| 90 | |
| 91 | * Special requests that don't actually correspond
|
| 92 | * to offsets in struct pt_regs.
|
| 93 |
|
| 94 | if (addr == PT_TEXT_ADDR) {
|
| 95 | val = child->mm->start_code;
|
| 96 | } else if (addr == PT_DATA_ADDR) {
|
| 97 | val = child->mm->start_data;
|
| 98 | } else if (addr == PT_TEXT_LEN) {
|
| 99 | val = child->mm->end_code
|
| 100 | - child->mm->start_code;
|
| 101 | } else {
|
| 102 | rval = -EIO;
|
| 103 | }
|
| 104 | } else if (request == PTRACE_POKEUSR &&
|
| 105 | (addr == PT_MSR || addr == PT_MODE)) {
|
| 106 | rval = -EIO;
|
| 107 | } else if (addr < PT_SIZE && (addr & 0x3) == 0) {
|
| 108 | microblaze_reg_t *reg_addr = reg_save_addr(addr, child);
|
| 109 | if (request == PTRACE_PEEKUSR)
|
| 110 | val = *reg_addr;
|
| 111 | else {
|
| 112 | #if 1
|
| 113 | *reg_addr = data;
|
| 114 | #else |
| 115 | /* MS potential problem on WB system
|
| 116 | * Be aware that reg_addr is virtual address
|
| 117 | * virt_to_phys conversion is necessary.
|
| 118 | * This could be sensible solution.
|
| 119 | */
|
| 120 | u32 paddr = virt_to_phys((u32)reg_addr);
|
| 121 | invalidate_icache_range(paddr, paddr + 4);
|
| 122 | *reg_addr = data;
|
| 123 | flush_dcache_range(paddr, paddr + 4);
|
| 124 | #endif
|
| 125 | }
|
| 126 | } else
|
| 127 | rval = -EIO;
|
| 128 |
|
| 129 | if (rval == 0 && request == PTRACE_PEEKUSR)
|
| 130 | rval = put_user(val, (unsigned long __user *)data);
|
| 131 | break;
|
| 132 | default:
|
| 133 | rval = ptrace_request(child, request, addr, data);
|
| 134 | }
|
| 135 | return rval;
|
| 136 | }
|
| 137 |
|
| 138 | asmlinkage unsigned long do_syscall_trace_enter(struct pt_regs *regs)
|
| 139 | {
|
| 140 | unsigned long ret = 0;
|
| 141 |
|
| 142 | secure_computing_strict(regs->r12);
|
| 143 |
|
| 144 | if (test_thread_flag(TIF_SYSCALL_TRACE) &&
|
| 145 | !ptrace_report_syscall_permit_entry(regs))
|
| 146 | |
| 147 | * Tracing decided this syscall should not happen.
|
| 148 | * We'll return a bogus call number to get an ENOSYS
|
| 149 | * error, but leave the original number in regs->regs[0].
|
| 150 |
|
| 151 | ret = -1L;
|
| 152 |
|
| 153 | audit_syscall_entry(regs->r12, regs->r5, regs->r6, regs->r7, regs->r8);
|
| 154 |
|
| 155 | return ret ?: regs->r12;
|
| 156 | }
|
| 157 |
|
| 158 | asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
|
| 159 | {
|
| 160 | int step;
|
| 161 |
|
| 162 | audit_syscall_exit(regs);
|
| 163 |
|
| 164 | step = test_thread_flag(TIF_SINGLESTEP);
|
| 165 | if (step || test_thread_flag(TIF_SYSCALL_TRACE))
|
| 166 | ptrace_report_syscall_exit(regs, step);
|
| 167 | }
|
| 168 |
|
| 169 | void ptrace_disable(struct task_struct *child)
|
| 170 | {
|
| 171 |
|
| 172 | }
|