target/linux/generic/hack-4.14/930-crashlog.patch

   1 From 6b1ab74a9917012d0c559edc4ed299d9228ac89f Mon Sep 17 00:00:00 2001
   2 From: Felix Fietkau <nbd@nbd.name>
   3 Date: Sat, 8 Jul 2017 08:26:47 +0200
   4 Subject: kernel: add the new 'crashlog' feature
   5
   6 this tries to store kernel oops/panic logs in a fixed location in RAM to
   7 recover them available to user space using debugfs
   8
   9 Signed-off-by: Felix Fietkau <nbd@nbd.name>
  10 ---
  11  include/linux/crashlog.h |  17 ++++
  12  init/Kconfig             |   4 +
  13  kernel/Makefile          |   1 +
  14  kernel/crashlog.c        | 213 +++++++++++++++++++++++++++++++++++++++++++++++
  15  kernel/module.c          |   3 +
  16  mm/bootmem.c             |   2 +
  17  mm/memblock.c            |   5 ++
  18  7 files changed, 245 insertions(+)
  19  create mode 100644 include/linux/crashlog.h
  20  create mode 100644 kernel/crashlog.c
  21
  22 --- /dev/null
  23 +++ b/include/linux/crashlog.h
  24 @@ -0,0 +1,17 @@
  25 +#ifndef __CRASHLOG_H
  26 +#define __CRASHLOG_H
  27 +
  28 +#ifdef CONFIG_CRASHLOG
  29 +void crashlog_init_bootmem(struct bootmem_data *bdata);
  30 +void crashlog_init_memblock(phys_addr_t addr, phys_addr_t size);
  31 +#else
  32 +static inline void crashlog_init_bootmem(struct bootmem_data *bdata)
  33 +{
  34 +}
  35 +
  36 +static inline void crashlog_init_memblock(phys_addr_t addr, phys_addr_t size)
  37 +{
  38 +}
  39 +#endif
  40 +
  41 +#endif
  42 --- a/init/Kconfig
  43 +++ b/init/Kconfig
  44 @@ -1009,6 +1009,10 @@ config RELAY
  45
  46           If unsure, say N.
  47
  48 +config CRASHLOG
  49 +       bool "Crash logging"
  50 +       depends on (!NO_BOOTMEM || HAVE_MEMBLOCK)
  51 +
  52  config BLK_DEV_INITRD
  53         bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
  54         depends on BROKEN || !FRV
  55 --- a/kernel/Makefile
  56 +++ b/kernel/Makefile
  57 @@ -112,6 +112,7 @@ obj-$(CONFIG_CONTEXT_TRACKING) += contex
  58  obj-$(CONFIG_TORTURE_TEST) += torture.o
  59
  60  obj-$(CONFIG_HAS_IOMEM) += memremap.o
  61 +obj-$(CONFIG_CRASHLOG) += crashlog.o
  62
  63  $(obj)/configs.o: $(obj)/config_data.h
  64
  65 --- /dev/null
  66 +++ b/kernel/crashlog.c
  67 @@ -0,0 +1,213 @@
  68 +/*
  69 + * Crash information logger
  70 + * Copyright (C) 2010 Felix Fietkau <nbd@nbd.name>
  71 + *
  72 + * Based on ramoops.c
  73 + *   Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
  74 + *
  75 + * This program is free software; you can redistribute it and/or
  76 + * modify it under the terms of the GNU General Public License
  77 + * version 2 as published by the Free Software Foundation.
  78 + *
  79 + * This program is distributed in the hope that it will be useful, but
  80 + * WITHOUT ANY WARRANTY; without even the implied warranty of
  81 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  82 + * General Public License for more details.
  83 + *
  84 + * You should have received a copy of the GNU General Public License
  85 + * along with this program; if not, write to the Free Software
  86 + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  87 + * 02110-1301 USA
  88 + *
  89 + */
  90 +
  91 +#include <linux/module.h>
  92 +#include <linux/bootmem.h>
  93 +#include <linux/memblock.h>
  94 +#include <linux/debugfs.h>
  95 +#include <linux/crashlog.h>
  96 +#include <linux/kmsg_dump.h>
  97 +#include <linux/module.h>
  98 +#include <linux/pfn.h>
  99 +#include <linux/vmalloc.h>
 100 +#include <asm/io.h>
 101 +
 102 +#define CRASHLOG_PAGES 4
 103 +#define CRASHLOG_SIZE  (CRASHLOG_PAGES * PAGE_SIZE)
 104 +#define CRASHLOG_MAGIC 0xa1eedead
 105 +
 106 +/*
 107 + * Start the log at 1M before the end of RAM, as some boot loaders like
 108 + * to use the end of the RAM for stack usage and other things
 109 + * If this fails, fall back to using the last part.
 110 + */
 111 +#define CRASHLOG_OFFSET        (1024 * 1024)
 112 +
 113 +struct crashlog_data {
 114 +       u32 magic;
 115 +       u32 len;
 116 +       u8 data[];
 117 +};
 118 +
 119 +static struct debugfs_blob_wrapper crashlog_blob;
 120 +static unsigned long crashlog_addr = 0;
 121 +static struct crashlog_data *crashlog_buf;
 122 +static struct kmsg_dumper dump;
 123 +static bool first = true;
 124 +
 125 +extern struct list_head *crashlog_modules;
 126 +
 127 +static bool crashlog_set_addr(phys_addr_t addr, phys_addr_t size)
 128 +{
 129 +       /* Limit to lower 64 MB to avoid highmem */
 130 +       phys_addr_t limit = 64 * 1024 * 1024;
 131 +
 132 +       if (crashlog_addr)
 133 +               return false;
 134 +
 135 +       if (addr > limit)
 136 +               return false;
 137 +
 138 +       if (addr + size > limit)
 139 +               size = limit - addr;
 140 +
 141 +       crashlog_addr = addr;
 142 +
 143 +       if (addr + size > CRASHLOG_OFFSET)
 144 +               crashlog_addr += size - CRASHLOG_OFFSET;
 145 +
 146 +       return true;
 147 +}
 148 +
 149 +#ifndef CONFIG_NO_BOOTMEM
 150 +void __init crashlog_init_bootmem(bootmem_data_t *bdata)
 151 +{
 152 +       phys_addr_t start, end;
 153 +
 154 +       start = PFN_PHYS(bdata->node_low_pfn);
 155 +       end = PFN_PHYS(bdata->node_min_pfn);
 156 +       if (!crashlog_set_addr(start, end - start))
 157 +               return;
 158 +
 159 +       if (reserve_bootmem(crashlog_addr, CRASHLOG_SIZE, BOOTMEM_EXCLUSIVE) < 0) {
 160 +               printk("Crashlog failed to allocate RAM at address 0x%lx\n",
 161 +                      crashlog_addr);
 162 +               crashlog_addr = 0;
 163 +       }
 164 +}
 165 +#endif
 166 +
 167 +#ifdef CONFIG_HAVE_MEMBLOCK
 168 +void __init_memblock crashlog_init_memblock(phys_addr_t addr, phys_addr_t size)
 169 +{
 170 +       if (!crashlog_set_addr(addr, size))
 171 +               return;
 172 +
 173 +       if (memblock_reserve(crashlog_addr, CRASHLOG_SIZE)) {
 174 +               printk("Crashlog failed to allocate RAM at address 0x%lx\n",
 175 +                      crashlog_addr);
 176 +               crashlog_addr = 0;
 177 +       }
 178 +}
 179 +#endif
 180 +
 181 +static void __init crashlog_copy(void)
 182 +{
 183 +       if (crashlog_buf->magic != CRASHLOG_MAGIC)
 184 +               return;
 185 +
 186 +       if (!crashlog_buf->len || crashlog_buf->len >
 187 +           CRASHLOG_SIZE - sizeof(*crashlog_buf))
 188 +               return;
 189 +
 190 +       crashlog_blob.size = crashlog_buf->len;
 191 +       crashlog_blob.data = kmemdup(crashlog_buf->data,
 192 +               crashlog_buf->len, GFP_KERNEL);
 193 +
 194 +       debugfs_create_blob("crashlog", 0700, NULL, &crashlog_blob);
 195 +}
 196 +
 197 +static int get_maxlen(void)
 198 +{
 199 +       return CRASHLOG_SIZE - sizeof(*crashlog_buf) - crashlog_buf->len;
 200 +}
 201 +
 202 +static void crashlog_printf(const char *fmt, ...)
 203 +{
 204 +       va_list args;
 205 +       int len = get_maxlen();
 206 +
 207 +       if (!len)
 208 +               return;
 209 +
 210 +       va_start(args, fmt);
 211 +       crashlog_buf->len += vscnprintf(
 212 +               &crashlog_buf->data[crashlog_buf->len],
 213 +               len, fmt, args);
 214 +       va_end(args);
 215 +}
 216 +
 217 +static void crashlog_do_dump(struct kmsg_dumper *dumper,
 218 +               enum kmsg_dump_reason reason)
 219 +{
 220 +       struct timeval tv;
 221 +       struct module *m;
 222 +       char *buf;
 223 +       size_t len;
 224 +
 225 +       if (!first)
 226 +               crashlog_printf("\n===================================\n");
 227 +
 228 +       do_gettimeofday(&tv);
 229 +       crashlog_printf("Time: %lu.%lu\n",
 230 +               (long)tv.tv_sec, (long)tv.tv_usec);
 231 +
 232 +       if (first) {
 233 +               crashlog_printf("Modules:");
 234 +               list_for_each_entry(m, crashlog_modules, list) {
 235 +                       crashlog_printf("\t%s@%p+%x", m->name,
 236 +                       m->core_layout.base, m->core_layout.size,
 237 +                       m->init_layout.base, m->init_layout.size);
 238 +               }
 239 +               crashlog_printf("\n");
 240 +               first = false;
 241 +       }
 242 +
 243 +       buf = (char *)&crashlog_buf->data[crashlog_buf->len];
 244 +
 245 +       kmsg_dump_get_buffer(dumper, true, buf, get_maxlen(), &len);
 246 +
 247 +       crashlog_buf->len += len;
 248 +}
 249 +
 250 +
 251 +int __init crashlog_init_fs(void)
 252 +{
 253 +       struct page *pages[CRASHLOG_PAGES];
 254 +       pgprot_t prot;
 255 +       int i;
 256 +
 257 +       if (!crashlog_addr) {
 258 +               printk("No memory allocated for crashlog\n");
 259 +               return -ENOMEM;
 260 +       }
 261 +
 262 +       printk("Crashlog allocated RAM at address 0x%lx\n", (unsigned long) crashlog_addr);
 263 +       for (i = 0; i < CRASHLOG_PAGES; i++)
 264 +               pages[i] = pfn_to_page((crashlog_addr >> PAGE_SHIFT) + i);
 265 +
 266 +       prot = pgprot_writecombine(PAGE_KERNEL);
 267 +       crashlog_buf = vmap(pages, CRASHLOG_PAGES, VM_MAP, prot);
 268 +
 269 +       crashlog_copy();
 270 +
 271 +       crashlog_buf->magic = CRASHLOG_MAGIC;
 272 +       crashlog_buf->len = 0;
 273 +
 274 +       dump.max_reason = KMSG_DUMP_OOPS;
 275 +       dump.dump = crashlog_do_dump;
 276 +       kmsg_dump_register(&dump);
 277 +
 278 +       return 0;
 279 +}
 280 +module_init(crashlog_init_fs);
 281 --- a/kernel/module.c
 282 +++ b/kernel/module.c
 283 @@ -256,6 +256,9 @@ static void mod_update_bounds(struct mod
 284  #ifdef CONFIG_KGDB_KDB
 285  struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
 286  #endif /* CONFIG_KGDB_KDB */
 287 +#ifdef CONFIG_CRASHLOG
 288 +struct list_head *crashlog_modules = &modules;
 289 +#endif
 290
 291  static void module_assert_mutex(void)
 292  {
 293 --- a/mm/bootmem.c
 294 +++ b/mm/bootmem.c
 295 @@ -15,6 +15,7 @@
 296  #include <linux/export.h>
 297  #include <linux/kmemleak.h>
 298  #include <linux/range.h>
 299 +#include <linux/crashlog.h>
 300  #include <linux/bug.h>
 301  #include <linux/io.h>
 302  #include <linux/bootmem.h>
 303 @@ -175,6 +176,7 @@ static unsigned long __init free_all_boo
 304         if (!bdata->node_bootmem_map)
 305                 return 0;
 306
 307 +       crashlog_init_bootmem(bdata);
 308         map = bdata->node_bootmem_map;
 309         start = bdata->node_min_pfn;
 310         end = bdata->node_low_pfn;
 311 --- a/mm/memblock.c
 312 +++ b/mm/memblock.c
 313 @@ -19,6 +19,7 @@
 314  #include <linux/debugfs.h>
 315  #include <linux/seq_file.h>
 316  #include <linux/memblock.h>
 317 +#include <linux/crashlog.h>
 318
 319  #include <asm/sections.h>
 320  #include <linux/io.h>
 321 @@ -483,6 +484,8 @@ static void __init_memblock memblock_ins
 322         memblock_set_region_node(rgn, nid);
 323         type->cnt++;
 324         type->total_size += size;
 325 +       if (type == &memblock.memory)
 326 +               crashlog_init_memblock(base, size);
 327  }
 328
 329  /**
 330 @@ -522,6 +525,8 @@ int __init_memblock memblock_add_range(s
 331                 type->regions[0].flags = flags;
 332                 memblock_set_region_node(&type->regions[0], nid);
 333                 type->total_size = size;
 334 +               if (type == &memblock.memory)
 335 +                       crashlog_init_memblock(base, size);
 336                 return 0;
 337         }
 338  repeat: