2 +++ b/include/linux/crashlog.h
7 +#ifdef CONFIG_CRASHLOG
8 +void __init crashlog_init_mem(struct bootmem_data *bdata);
10 +static inline void crashlog_init_mem(struct bootmem_data *bdata)
18 @@ -719,6 +719,9 @@ config NET_NS
19 Allow user space to create what appear to be multiple instances
23 + bool "Crash logging"
26 bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support"
27 depends on BROKEN || !FRV
30 @@ -100,6 +100,7 @@ obj-$(CONFIG_SLOW_WORK_DEBUG) += slow-wo
31 obj-$(CONFIG_PERF_EVENTS) += perf_event.o
32 obj-$(CONFIG_HAVE_HW_BREAKPOINT) += hw_breakpoint.o
33 obj-$(CONFIG_USER_RETURN_NOTIFIER) += user-return-notifier.o
34 +obj-$(CONFIG_CRASHLOG) += crashlog.o
36 ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y)
37 # According to Alan Modra <alan@linuxcare.com.au>, the -fno-omit-frame-pointer is
39 +++ b/kernel/crashlog.c
42 + * Crash information logger
43 + * Copyright (C) 2010 Felix Fietkau <nbd@openwrt.org>
45 + * Based on ramoops.c
46 + * Copyright (C) 2010 Marco Stornelli <marco.stornelli@gmail.com>
48 + * This program is free software; you can redistribute it and/or
49 + * modify it under the terms of the GNU General Public License
50 + * version 2 as published by the Free Software Foundation.
52 + * This program is distributed in the hope that it will be useful, but
53 + * WITHOUT ANY WARRANTY; without even the implied warranty of
54 + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
55 + * General Public License for more details.
57 + * You should have received a copy of the GNU General Public License
58 + * along with this program; if not, write to the Free Software
59 + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
64 +#include <linux/module.h>
65 +#include <linux/bootmem.h>
66 +#include <linux/debugfs.h>
67 +#include <linux/crashlog.h>
68 +#include <linux/kmsg_dump.h>
69 +#include <linux/module.h>
70 +#include <linux/pfn.h>
73 +#define CRASHLOG_PAGES 4
74 +#define CRASHLOG_SIZE (CRASHLOG_PAGES * PAGE_SIZE)
75 +#define CRASHLOG_MAGIC 0xa1eedead
78 + * Start the log at 1M before the end of RAM, as some boot loaders like
79 + * to use the end of the RAM for stack usage and other things
80 + * If this fails, fall back to using the last part.
82 +#define CRASHLOG_OFFSET (1024 * 1024)
84 +struct crashlog_data {
90 +static struct debugfs_blob_wrapper crashlog_blob;
91 +static unsigned long crashlog_addr = 0;
92 +static struct crashlog_data *crashlog_buf;
93 +static struct kmsg_dumper dump;
94 +static bool first = true;
96 +extern struct list_head *crashlog_modules;
98 +void __init crashlog_init_mem(bootmem_data_t *bdata)
100 + unsigned long addr;
105 + addr = PFN_PHYS(bdata->node_low_pfn) - CRASHLOG_OFFSET;
106 + if (reserve_bootmem(addr, CRASHLOG_SIZE, BOOTMEM_EXCLUSIVE) < 0) {
107 + printk("Crashlog failed to allocate RAM at address 0x%lx\n", addr);
108 + bdata->node_low_pfn -= CRASHLOG_PAGES;
109 + addr = PFN_PHYS(bdata->node_low_pfn);
111 + crashlog_addr = addr;
114 +static void __init crashlog_copy(void)
116 + if (crashlog_buf->magic != CRASHLOG_MAGIC)
119 + if (!crashlog_buf->len || crashlog_buf->len >
120 + CRASHLOG_SIZE - sizeof(*crashlog_buf))
123 + crashlog_blob.size = crashlog_buf->len;
124 + crashlog_blob.data = kmemdup(crashlog_buf->data,
125 + crashlog_buf->len, GFP_KERNEL);
127 + debugfs_create_blob("crashlog", 0700, NULL, &crashlog_blob);
130 +static int get_maxlen(void)
132 + return CRASHLOG_SIZE - sizeof(*crashlog_buf) - crashlog_buf->len;
135 +static void crashlog_printf(const char *fmt, ...)
138 + int len = get_maxlen();
143 + va_start(args, fmt);
144 + crashlog_buf->len += vsnprintf(
145 + &crashlog_buf->data[crashlog_buf->len],
150 +static void crashlog_do_dump(struct kmsg_dumper *dumper,
151 + enum kmsg_dump_reason reason, const char *s1, unsigned long l1,
152 + const char *s2, unsigned long l2)
154 + unsigned long s1_start, s2_start;
155 + unsigned long l1_cpy, l2_cpy;
162 + crashlog_printf("\n===================================\n");
164 + do_gettimeofday(&tv);
165 + crashlog_printf("Time: %lu.%lu\n",
166 + (long)tv.tv_sec, (long)tv.tv_usec);
169 + crashlog_printf("Modules:");
170 + list_for_each_entry(m, crashlog_modules, list) {
171 + crashlog_printf("\t%s@%p+%x", m->name,
172 + m->module_core, m->core_size,
173 + m->module_init, m->init_size);
175 + crashlog_printf("\n");
179 + buf = (char *)&crashlog_buf->data[crashlog_buf->len];
180 + len = get_maxlen();
182 + l2_cpy = min(l2, (unsigned long)len);
183 + l1_cpy = min(l1, (unsigned long)len - l2_cpy);
185 + s2_start = l2 - l2_cpy;
186 + s1_start = l1 - l1_cpy;
188 + memcpy(buf, s1 + s1_start, l1_cpy);
189 + memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy);
190 + crashlog_buf->len += l1_cpy + l2_cpy;
194 +int __init crashlog_init_fs(void)
196 + if (!crashlog_addr)
199 + crashlog_buf = ioremap(crashlog_addr, CRASHLOG_SIZE);
203 + crashlog_buf->magic = CRASHLOG_MAGIC;
204 + crashlog_buf->len = 0;
206 + dump.dump = crashlog_do_dump;
207 + kmsg_dump_register(&dump);
211 +module_init(crashlog_init_fs);
215 #include <linux/bootmem.h>
216 #include <linux/module.h>
217 #include <linux/kmemleak.h>
218 +#include <linux/crashlog.h>
222 @@ -176,6 +177,7 @@ static unsigned long __init free_all_boo
223 if (!bdata->node_bootmem_map)
226 + crashlog_init_mem(bdata);
227 start = bdata->node_min_pfn;
228 end = bdata->node_low_pfn;
230 --- a/kernel/module.c
231 +++ b/kernel/module.c
232 @@ -79,6 +79,9 @@ EXPORT_TRACEPOINT_SYMBOL(module_get);
233 DEFINE_MUTEX(module_mutex);
234 EXPORT_SYMBOL_GPL(module_mutex);
235 static LIST_HEAD(modules);
236 +#ifdef CONFIG_CRASHLOG
237 +struct list_head *crashlog_modules = &modules;
240 /* Block module loading/unloading? */
241 int modules_disabled = 0;