helpers.cc revision 11538 
1/*
2 * Copyright (c) 2016 ARM Limited
3 * All rights reserved
4 *
5 * The license below extends only to copyright in the software and shall
6 * not be construed as granting a license to any other intellectual
7 * property including but not limited to intellectual property relating
8 * to a hardware implementation of the functionality of the software
9 * licensed hereunder.  You may use the software subject to the license
10 * terms below provided that you ensure that this notice is replicated
11 * unmodified and in its entirety in all distributions of the software,
12 * modified or unmodified, in source code or in binary form.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions are
16 * met: redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer;
18 * redistributions in binary form must reproduce the above copyright
19 * notice, this list of conditions and the following disclaimer in the
20 * documentation and/or other materials provided with the distribution;
21 * neither the name of the copyright holders nor the names of its
22 * contributors may be used to endorse or promote products derived from
23 * this software without specific prior written permission.
24 *
25 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
26 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
27 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
28 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
29 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
30 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
31 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
32 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
33 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
34 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
35 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
36 *
37 * Authors: Andreas Sandberg
38 */
39
40#include "kern/linux/helpers.hh"
41
42#include "arch/isa_traits.hh"
43#include "config/the_isa.hh"
44#include "cpu/thread_context.hh"
45#include "mem/fs_translating_port_proxy.hh"
46#include "sim/system.hh"
47
48struct DmesgEntry {
49    uint64_t ts_nsec;
50    uint16_t len;
51    uint16_t text_len;
52    uint16_t dict_len;
53    uint8_t facility;
54    uint8_t flags;
55} M5_ATTR_PACKED;
56
57static int
58dumpDmesgEntry(const uint8_t *base, const uint8_t *end, std::ostream &os)
59{
60    const size_t max_length = end - base;
61    DmesgEntry de;
62
63    if (max_length < sizeof(de)) {
64        warn("Malformed dmesg entry\n");
65        return -1;
66    }
67
68    memcpy(&de, base, sizeof(de));
69    de.ts_nsec = TheISA::gtoh(de.ts_nsec);
70    de.len = TheISA::gtoh(de.len);
71    de.text_len = TheISA::gtoh(de.text_len);
72
73    if (de.len < sizeof(de) ||
74        max_length < de.len ||
75        max_length < sizeof(DmesgEntry) + de.text_len) {
76
77        warn("Malformed dmesg entry:\n");
78        warn("\tMax length: %i\n", max_length);
79        warn("\tde.len: %i\n", de.len);
80        warn("\tde.text_len: %i\n", de.text_len);
81        return -1;
82    }
83
84    ccprintf(os, "[%.6f] ", de.ts_nsec * 10e-9);
85    os.write((char *)base + sizeof(de), de.text_len);
86    os << std::endl;
87
88    return de.len;
89}
90
91void
92Linux::dumpDmesg(ThreadContext *tc, std::ostream &os)
93{
94    System *system = tc->getSystemPtr();
95    const SymbolTable *symtab = system->kernelSymtab;
96    FSTranslatingPortProxy proxy(tc);
97
98    Addr addr_lb = 0, addr_lb_len = 0, addr_first = 0, addr_next = 0;
99    const bool found_symbols =
100        symtab->findAddress("__log_buf", addr_lb) &&
101        symtab->findAddress("log_buf_len", addr_lb_len) &&
102        symtab->findAddress("log_first_idx", addr_first) &&
103        symtab->findAddress("log_next_idx", addr_next);
104
105    if (!found_symbols) {
106        warn("Failed to find kernel dmesg symbols.\n");
107        return;
108    }
109
110    uint32_t log_buf_len = proxy.readGtoH<uint32_t>(addr_lb_len);
111    uint32_t log_first_idx = proxy.readGtoH<uint32_t>(addr_first);
112    uint32_t log_next_idx = proxy.readGtoH<uint32_t>(addr_next);
113
114    if (log_first_idx >= log_buf_len || log_next_idx >= log_buf_len) {
115        warn("dmesg pointers/length corrupted\n");
116        return;
117    }
118
119    // Normalize and read the dmesg ring buffer
120    std::vector<uint8_t> log_buf(log_buf_len);
121    int length;
122    if (log_first_idx < log_next_idx) {
123        length = log_next_idx - log_first_idx;
124        if (length < 0 || length > log_buf.size()) {
125            warn("Unexpected dmesg buffer length\n");
126            return;
127        }
128        proxy.readBlob(addr_lb + log_first_idx, log_buf.data(), length);
129    } else {
130        const int length_2 = log_buf_len - log_first_idx;
131        if (length_2 < 0 || length_2 + log_next_idx > log_buf.size()) {
132            warn("Unexpected dmesg buffer length\n");
133            return;
134        }
135        length = log_buf_len;
136        proxy.readBlob(addr_lb + log_first_idx, log_buf.data(), length_2);
137        proxy.readBlob(addr_lb, log_buf.data() + length_2, log_next_idx);
138    }
139
140    // Print dmesg buffer content
141    const uint8_t *cur = log_buf.data(), *end = log_buf.data() + length;
142    while (cur < end) {
143        int ret = dumpDmesgEntry(cur, end, os);
144        if (ret < 0)
145            return;
146        cur += ret;
147    }
148}
149