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2b438454 MS |
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> | |
2b438454 MS |
30 | #include <linux/ptrace.h> |
31 | #include <linux/signal.h> | |
23575483 MS |
32 | #include <linux/elf.h> |
33 | #include <linux/audit.h> | |
34 | #include <linux/seccomp.h> | |
35 | #include <linux/tracehook.h> | |
2b438454 MS |
36 | |
37 | #include <linux/errno.h> | |
2b438454 MS |
38 | #include <asm/processor.h> |
39 | #include <linux/uaccess.h> | |
40 | #include <asm/asm-offsets.h> | |
6847ba91 | 41 | #include <asm/cacheflush.h> |
c1df53b3 | 42 | #include <asm/syscall.h> |
6bd55f0b | 43 | #include <linux/io.h> |
2b438454 MS |
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 | ||
9b05a69e NK |
77 | long arch_ptrace(struct task_struct *child, long request, |
78 | unsigned long addr, unsigned long data) | |
2b438454 MS |
79 | { |
80 | int rval; | |
81 | unsigned long val = 0; | |
2b438454 MS |
82 | |
83 | switch (request) { | |
2b438454 MS |
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 | } | |
cfd866f6 | 104 | } else if (addr < PT_SIZE && (addr & 0x3) == 0) { |
2b438454 MS |
105 | microblaze_reg_t *reg_addr = reg_save_addr(addr, child); |
106 | if (request == PTRACE_PEEKUSR) | |
107 | val = *reg_addr; | |
6847ba91 MS |
108 | else { |
109 | #if 1 | |
2b438454 | 110 | *reg_addr = data; |
6847ba91 MS |
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 | } | |
2b438454 MS |
123 | } else |
124 | rval = -EIO; | |
125 | ||
126 | if (rval == 0 && request == PTRACE_PEEKUSR) | |
c1df53b3 | 127 | rval = put_user(val, (unsigned long __user *)data); |
2b438454 | 128 | break; |
2b438454 | 129 | default: |
b3c1e01a | 130 | rval = ptrace_request(child, request, addr, data); |
2b438454 MS |
131 | } |
132 | return rval; | |
133 | } | |
134 | ||
8543e6c9 | 135 | asmlinkage unsigned long do_syscall_trace_enter(struct pt_regs *regs) |
23575483 | 136 | { |
8543e6c9 | 137 | unsigned long ret = 0; |
23575483 | 138 | |
e4da89d0 | 139 | secure_computing_strict(regs->r12); |
23575483 MS |
140 | |
141 | if (test_thread_flag(TIF_SYSCALL_TRACE) && | |
142 | tracehook_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 | ||
91397401 | 150 | audit_syscall_entry(regs->r12, regs->r5, regs->r6, regs->r7, regs->r8); |
23575483 MS |
151 | |
152 | return ret ?: regs->r12; | |
153 | } | |
154 | ||
155 | asmlinkage void do_syscall_trace_leave(struct pt_regs *regs) | |
156 | { | |
157 | int step; | |
158 | ||
d7e7528b | 159 | audit_syscall_exit(regs); |
23575483 MS |
160 | |
161 | step = test_thread_flag(TIF_SINGLESTEP); | |
162 | if (step || test_thread_flag(TIF_SYSCALL_TRACE)) | |
163 | tracehook_report_syscall_exit(regs, step); | |
164 | } | |
165 | ||
2b438454 MS |
166 | void ptrace_disable(struct task_struct *child) |
167 | { | |
168 | /* nothing to do */ | |
169 | } |