OpenWrt – Blame information for rev 1
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Rev | Author | Line No. | Line |
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1 | office | 1 | From 6b1ab74a9917012d0c559edc4ed299d9228ac89f Mon Sep 17 00:00:00 2001 |
2 | From: Felix Fietkau <nbd@nbd.name> |
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3 | Date: Sat, 8 Jul 2017 08:26:47 +0200 |
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4 | Subject: kernel: add the new 'crashlog' feature |
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5 | |||
6 | this tries to store kernel oops/panic logs in a fixed location in RAM to |
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7 | recover them available to user space using debugfs |
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8 | |||
9 | Signed-off-by: Felix Fietkau <nbd@nbd.name> |
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10 | --- |
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11 | include/linux/crashlog.h | 17 ++++ |
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12 | init/Kconfig | 4 + |
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13 | kernel/Makefile | 1 + |
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14 | kernel/crashlog.c | 213 +++++++++++++++++++++++++++++++++++++++++++++++ |
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15 | kernel/module.c | 3 + |
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16 | mm/bootmem.c | 2 + |
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17 | mm/memblock.c | 5 ++ |
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18 | 7 files changed, 245 insertions(+) |
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19 | create mode 100644 include/linux/crashlog.h |
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20 | create mode 100644 kernel/crashlog.c |
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21 | |||
22 | --- /dev/null |
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23 | +++ b/include/linux/crashlog.h |
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24 | @@ -0,0 +1,17 @@ |
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25 | +#ifndef __CRASHLOG_H |
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26 | +#define __CRASHLOG_H |
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27 | + |
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28 | +#ifdef CONFIG_CRASHLOG |
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29 | +void crashlog_init_bootmem(struct bootmem_data *bdata); |
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30 | +void crashlog_init_memblock(phys_addr_t addr, phys_addr_t size); |
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31 | +#else |
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32 | +static inline void crashlog_init_bootmem(struct bootmem_data *bdata) |
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33 | +{ |
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34 | +} |
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35 | + |
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36 | +static inline void crashlog_init_memblock(phys_addr_t addr, phys_addr_t size) |
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37 | +{ |
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38 | +} |
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39 | +#endif |
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40 | + |
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41 | +#endif |
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42 | --- a/init/Kconfig |
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43 | +++ b/init/Kconfig |
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44 | @@ -1298,6 +1298,10 @@ config RELAY |
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45 | |||
46 | If unsure, say N. |
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47 | |||
48 | +config CRASHLOG |
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49 | + bool "Crash logging" |
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50 | + depends on (!NO_BOOTMEM || HAVE_MEMBLOCK) |
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51 | + |
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52 | config BLK_DEV_INITRD |
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53 | bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" |
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54 | depends on BROKEN || !FRV |
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55 | --- a/kernel/Makefile |
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56 | +++ b/kernel/Makefile |
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57 | @@ -113,6 +113,7 @@ obj-$(CONFIG_TORTURE_TEST) += torture.o |
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58 | obj-$(CONFIG_MEMBARRIER) += membarrier.o |
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59 | |||
60 | obj-$(CONFIG_HAS_IOMEM) += memremap.o |
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61 | +obj-$(CONFIG_CRASHLOG) += crashlog.o |
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62 | |||
63 | $(obj)/configs.o: $(obj)/config_data.h |
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64 | |||
65 | --- /dev/null |
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66 | +++ b/kernel/crashlog.c |
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67 | @@ -0,0 +1,213 @@ |
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68 | +/* |
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69 | + * Crash information logger |
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70 | + * Copyright (C) 2010 Felix Fietkau <nbd@nbd.name> |
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71 | + * |
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72 | + * Based on ramoops.c |
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73 | + * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com> |
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74 | + * |
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75 | + * This program is free software; you can redistribute it and/or |
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76 | + * modify it under the terms of the GNU General Public License |
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77 | + * version 2 as published by the Free Software Foundation. |
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78 | + * |
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79 | + * This program is distributed in the hope that it will be useful, but |
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80 | + * WITHOUT ANY WARRANTY; without even the implied warranty of |
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81 | + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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82 | + * General Public License for more details. |
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83 | + * |
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84 | + * You should have received a copy of the GNU General Public License |
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85 | + * along with this program; if not, write to the Free Software |
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86 | + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA |
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87 | + * 02110-1301 USA |
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88 | + * |
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89 | + */ |
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90 | + |
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91 | +#include <linux/module.h> |
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92 | +#include <linux/bootmem.h> |
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93 | +#include <linux/memblock.h> |
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94 | +#include <linux/debugfs.h> |
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95 | +#include <linux/crashlog.h> |
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96 | +#include <linux/kmsg_dump.h> |
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97 | +#include <linux/module.h> |
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98 | +#include <linux/pfn.h> |
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99 | +#include <linux/vmalloc.h> |
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100 | +#include <asm/io.h> |
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101 | + |
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102 | +#define CRASHLOG_PAGES 4 |
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103 | +#define CRASHLOG_SIZE (CRASHLOG_PAGES * PAGE_SIZE) |
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104 | +#define CRASHLOG_MAGIC 0xa1eedead |
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105 | + |
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106 | +/* |
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107 | + * Start the log at 1M before the end of RAM, as some boot loaders like |
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108 | + * to use the end of the RAM for stack usage and other things |
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109 | + * If this fails, fall back to using the last part. |
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110 | + */ |
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111 | +#define CRASHLOG_OFFSET (1024 * 1024) |
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112 | + |
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113 | +struct crashlog_data { |
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114 | + u32 magic; |
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115 | + u32 len; |
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116 | + u8 data[]; |
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117 | +}; |
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118 | + |
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119 | +static struct debugfs_blob_wrapper crashlog_blob; |
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120 | +static unsigned long crashlog_addr = 0; |
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121 | +static struct crashlog_data *crashlog_buf; |
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122 | +static struct kmsg_dumper dump; |
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123 | +static bool first = true; |
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124 | + |
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125 | +extern struct list_head *crashlog_modules; |
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126 | + |
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127 | +static bool crashlog_set_addr(phys_addr_t addr, phys_addr_t size) |
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128 | +{ |
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129 | + /* Limit to lower 64 MB to avoid highmem */ |
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130 | + phys_addr_t limit = 64 * 1024 * 1024; |
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131 | + |
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132 | + if (crashlog_addr) |
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133 | + return false; |
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134 | + |
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135 | + if (addr > limit) |
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136 | + return false; |
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137 | + |
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138 | + if (addr + size > limit) |
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139 | + size = limit - addr; |
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140 | + |
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141 | + crashlog_addr = addr; |
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142 | + |
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143 | + if (addr + size > CRASHLOG_OFFSET) |
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144 | + crashlog_addr += size - CRASHLOG_OFFSET; |
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145 | + |
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146 | + return true; |
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147 | +} |
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148 | + |
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149 | +#ifndef CONFIG_NO_BOOTMEM |
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150 | +void __init crashlog_init_bootmem(bootmem_data_t *bdata) |
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151 | +{ |
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152 | + phys_addr_t start, end; |
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153 | + |
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154 | + start = PFN_PHYS(bdata->node_low_pfn); |
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155 | + end = PFN_PHYS(bdata->node_min_pfn); |
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156 | + if (!crashlog_set_addr(start, end - start)) |
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157 | + return; |
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158 | + |
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159 | + if (reserve_bootmem(crashlog_addr, CRASHLOG_SIZE, BOOTMEM_EXCLUSIVE) < 0) { |
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160 | + printk("Crashlog failed to allocate RAM at address 0x%lx\n", |
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161 | + crashlog_addr); |
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162 | + crashlog_addr = 0; |
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163 | + } |
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164 | +} |
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165 | +#endif |
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166 | + |
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167 | +#ifdef CONFIG_HAVE_MEMBLOCK |
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168 | +void __init_memblock crashlog_init_memblock(phys_addr_t addr, phys_addr_t size) |
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169 | +{ |
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170 | + if (!crashlog_set_addr(addr, size)) |
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171 | + return; |
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172 | + |
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173 | + if (memblock_reserve(crashlog_addr, CRASHLOG_SIZE)) { |
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174 | + printk("Crashlog failed to allocate RAM at address 0x%lx\n", |
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175 | + crashlog_addr); |
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176 | + crashlog_addr = 0; |
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177 | + } |
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178 | +} |
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179 | +#endif |
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180 | + |
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181 | +static void __init crashlog_copy(void) |
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182 | +{ |
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183 | + if (crashlog_buf->magic != CRASHLOG_MAGIC) |
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184 | + return; |
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185 | + |
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186 | + if (!crashlog_buf->len || crashlog_buf->len > |
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187 | + CRASHLOG_SIZE - sizeof(*crashlog_buf)) |
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188 | + return; |
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189 | + |
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190 | + crashlog_blob.size = crashlog_buf->len; |
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191 | + crashlog_blob.data = kmemdup(crashlog_buf->data, |
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192 | + crashlog_buf->len, GFP_KERNEL); |
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193 | + |
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194 | + debugfs_create_blob("crashlog", 0700, NULL, &crashlog_blob); |
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195 | +} |
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196 | + |
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197 | +static int get_maxlen(void) |
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198 | +{ |
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199 | + return CRASHLOG_SIZE - sizeof(*crashlog_buf) - crashlog_buf->len; |
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200 | +} |
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201 | + |
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202 | +static void crashlog_printf(const char *fmt, ...) |
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203 | +{ |
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204 | + va_list args; |
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205 | + int len = get_maxlen(); |
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206 | + |
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207 | + if (!len) |
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208 | + return; |
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209 | + |
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210 | + va_start(args, fmt); |
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211 | + crashlog_buf->len += vscnprintf( |
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212 | + &crashlog_buf->data[crashlog_buf->len], |
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213 | + len, fmt, args); |
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214 | + va_end(args); |
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215 | +} |
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216 | + |
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217 | +static void crashlog_do_dump(struct kmsg_dumper *dumper, |
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218 | + enum kmsg_dump_reason reason) |
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219 | +{ |
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220 | + struct timeval tv; |
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221 | + struct module *m; |
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222 | + char *buf; |
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223 | + size_t len; |
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224 | + |
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225 | + if (!first) |
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226 | + crashlog_printf("\n===================================\n"); |
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227 | + |
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228 | + do_gettimeofday(&tv); |
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229 | + crashlog_printf("Time: %lu.%lu\n", |
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230 | + (long)tv.tv_sec, (long)tv.tv_usec); |
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231 | + |
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232 | + if (first) { |
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233 | + crashlog_printf("Modules:"); |
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234 | + list_for_each_entry(m, crashlog_modules, list) { |
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235 | + crashlog_printf("\t%s@%p+%x", m->name, |
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236 | + m->core_layout.base, m->core_layout.size, |
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237 | + m->init_layout.base, m->init_layout.size); |
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238 | + } |
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239 | + crashlog_printf("\n"); |
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240 | + first = false; |
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241 | + } |
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242 | + |
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243 | + buf = (char *)&crashlog_buf->data[crashlog_buf->len]; |
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244 | + |
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245 | + kmsg_dump_get_buffer(dumper, true, buf, get_maxlen(), &len); |
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246 | + |
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247 | + crashlog_buf->len += len; |
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248 | +} |
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249 | + |
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250 | + |
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251 | +int __init crashlog_init_fs(void) |
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252 | +{ |
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253 | + struct page *pages[CRASHLOG_PAGES]; |
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254 | + pgprot_t prot; |
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255 | + int i; |
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256 | + |
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257 | + if (!crashlog_addr) { |
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258 | + printk("No memory allocated for crashlog\n"); |
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259 | + return -ENOMEM; |
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260 | + } |
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261 | + |
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262 | + printk("Crashlog allocated RAM at address 0x%lx\n", (unsigned long) crashlog_addr); |
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263 | + for (i = 0; i < CRASHLOG_PAGES; i++) |
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264 | + pages[i] = pfn_to_page((crashlog_addr >> PAGE_SHIFT) + i); |
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265 | + |
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266 | + prot = pgprot_writecombine(PAGE_KERNEL); |
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267 | + crashlog_buf = vmap(pages, CRASHLOG_PAGES, VM_MAP, prot); |
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268 | + |
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269 | + crashlog_copy(); |
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270 | + |
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271 | + crashlog_buf->magic = CRASHLOG_MAGIC; |
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272 | + crashlog_buf->len = 0; |
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273 | + |
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274 | + dump.max_reason = KMSG_DUMP_OOPS; |
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275 | + dump.dump = crashlog_do_dump; |
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276 | + kmsg_dump_register(&dump); |
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277 | + |
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278 | + return 0; |
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279 | +} |
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280 | +module_init(crashlog_init_fs); |
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281 | --- a/kernel/module.c |
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282 | +++ b/kernel/module.c |
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283 | @@ -253,6 +253,9 @@ static void mod_update_bounds(struct mod |
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284 | #ifdef CONFIG_KGDB_KDB |
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285 | struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */ |
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286 | #endif /* CONFIG_KGDB_KDB */ |
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287 | +#ifdef CONFIG_CRASHLOG |
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288 | +struct list_head *crashlog_modules = &modules; |
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289 | +#endif |
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290 | |||
291 | static void module_assert_mutex(void) |
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292 | { |
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293 | --- a/mm/bootmem.c |
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294 | +++ b/mm/bootmem.c |
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295 | @@ -14,6 +14,7 @@ |
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296 | #include <linux/export.h> |
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297 | #include <linux/kmemleak.h> |
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298 | #include <linux/range.h> |
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299 | +#include <linux/crashlog.h> |
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300 | #include <linux/bug.h> |
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301 | #include <linux/io.h> |
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302 | #include <linux/bootmem.h> |
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303 | @@ -174,6 +175,7 @@ static unsigned long __init free_all_boo |
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304 | if (!bdata->node_bootmem_map) |
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305 | return 0; |
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306 | |||
307 | + crashlog_init_bootmem(bdata); |
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308 | map = bdata->node_bootmem_map; |
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309 | start = bdata->node_min_pfn; |
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310 | end = bdata->node_low_pfn; |
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311 | --- a/mm/memblock.c |
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312 | +++ b/mm/memblock.c |
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313 | @@ -19,6 +19,7 @@ |
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314 | #include <linux/debugfs.h> |
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315 | #include <linux/seq_file.h> |
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316 | #include <linux/memblock.h> |
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317 | +#include <linux/crashlog.h> |
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318 | |||
319 | #include <asm/sections.h> |
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320 | #include <linux/io.h> |
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321 | @@ -495,6 +496,8 @@ static void __init_memblock memblock_ins |
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322 | memblock_set_region_node(rgn, nid); |
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323 | type->cnt++; |
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324 | type->total_size += size; |
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325 | + if (type == &memblock.memory) |
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326 | + crashlog_init_memblock(base, size); |
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327 | } |
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328 | |||
329 | /** |
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330 | @@ -534,6 +537,8 @@ int __init_memblock memblock_add_range(s |
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331 | type->regions[0].flags = flags; |
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332 | memblock_set_region_node(&type->regions[0], nid); |
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333 | type->total_size = size; |
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334 | + if (type == &memblock.memory) |
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335 | + crashlog_init_memblock(base, size); |
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336 | return 0; |
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337 | } |
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338 | repeat: |