1 | /* |
2 | * `ptrace' system call |
3 | * |
4 | * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> |
5 | * Copyright (C) 2007-2009 PetaLogix |
6 | * Copyright (C) 2004-2007 John Williams <john.williams@petalogix.com> |
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 <miles@gnu.org> |
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, kevink@mips.com and Carsten Langgaard, carstenl@mips.com |
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 | /* Returns the address where the register at REG_OFFS in P is stashed away. */ |
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 | /* Register saved during kernel entry (or not available). */ |
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 | /* Read/write the word at location ADDR in the registers. */ |
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 (addr < PT_SIZE && (addr & 0x3) == 0) { |
105 | microblaze_reg_t *reg_addr = reg_save_addr(addr, child); |
106 | if (request == PTRACE_PEEKUSR) |
107 | val = *reg_addr; |
108 | else { |
109 | #if 1 |
110 | *reg_addr = data; |
111 | #else |
112 | /* MS potential problem on WB system |
113 | * Be aware that reg_addr is virtual address |
114 | * virt_to_phys conversion is necessary. |
115 | * This could be sensible solution. |
116 | */ |
117 | u32 paddr = virt_to_phys((u32)reg_addr); |
118 | invalidate_icache_range(paddr, paddr + 4); |
119 | *reg_addr = data; |
120 | flush_dcache_range(paddr, paddr + 4); |
121 | #endif |
122 | } |
123 | } else |
124 | rval = -EIO; |
125 | |
126 | if (rval == 0 && request == PTRACE_PEEKUSR) |
127 | rval = put_user(val, (unsigned long __user *)data); |
128 | break; |
129 | default: |
130 | rval = ptrace_request(child, request, addr, data); |
131 | } |
132 | return rval; |
133 | } |
134 | |
135 | asmlinkage unsigned long do_syscall_trace_enter(struct pt_regs *regs) |
136 | { |
137 | unsigned long ret = 0; |
138 | |
139 | secure_computing_strict(regs->r12); |
140 | |
141 | if (test_thread_flag(TIF_SYSCALL_TRACE) && |
142 | ptrace_report_syscall_entry(regs)) |
143 | /* |
144 | * Tracing decided this syscall should not happen. |
145 | * We'll return a bogus call number to get an ENOSYS |
146 | * error, but leave the original number in regs->regs[0]. |
147 | */ |
148 | ret = -1L; |
149 | |
150 | audit_syscall_entry(major: regs->r12, a0: regs->r5, a1: regs->r6, a2: regs->r7, a3: regs->r8); |
151 | |
152 | return ret ?: regs->r12; |
153 | } |
154 | |
155 | asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) |
156 | { |
157 | int step; |
158 | |
159 | audit_syscall_exit(pt_regs: regs); |
160 | |
161 | step = test_thread_flag(TIF_SINGLESTEP); |
162 | if (step || test_thread_flag(TIF_SYSCALL_TRACE)) |
163 | ptrace_report_syscall_exit(regs, step); |
164 | } |
165 | |
166 | void ptrace_disable(struct task_struct *child) |
167 | { |
168 | /* nothing to do */ |
169 | } |
170 | |