--- a/init/Kconfig +++ b/init/Kconfig @@ -723,6 +723,9 @@ Allow user space to create what appear to be multiple instances of the network stack. +config CRASHLOG + bool "Crash logging" + config BLK_DEV_INITRD bool "Initial RAM filesystem and RAM disk (initramfs/initrd) support" depends on BROKEN || !FRV --- a/kernel/Makefile +++ b/kernel/Makefile @@ -95,6 +95,7 @@ obj-$(CONFIG_TRACING) += trace/ obj-$(CONFIG_SMP) += sched_cpupri.o obj-$(CONFIG_SLOW_WORK) += slow-work.o +obj-$(CONFIG_CRASHLOG) += crashlog.o ifneq ($(CONFIG_SCHED_OMIT_FRAME_POINTER),y) # According to Alan Modra , the -fno-omit-frame-pointer is --- a/mm/bootmem.c +++ b/mm/bootmem.c @@ -12,6 +12,7 @@ #include #include #include +#include #include #include @@ -151,6 +152,7 @@ if (!bdata->node_bootmem_map) return 0; + crashlog_init_mem(bdata); start = bdata->node_min_pfn; end = bdata->node_low_pfn; --- a/kernel/module.c +++ b/kernel/module.c @@ -71,6 +71,9 @@ DEFINE_MUTEX(module_mutex); EXPORT_SYMBOL_GPL(module_mutex); static LIST_HEAD(modules); +#ifdef CONFIG_CRASHLOG +struct list_head *crashlog_modules = &modules; +#endif /* Waiting for a module to finish initializing? */ static DECLARE_WAIT_QUEUE_HEAD(module_wq); --- /dev/null +++ b/include/linux/crashlog.h @@ -0,0 +1,12 @@ +#ifndef __CRASHLOG_H +#define __CRASHLOG_H + +#ifdef CONFIG_CRASHLOG +void __init crashlog_init_mem(struct bootmem_data *bdata); +#else +static inline void crashlog_init_mem(struct bootmem_data *bdata) +{ +} +#endif + +#endif --- /dev/null +++ b/kernel/crashlog.c @@ -0,0 +1,171 @@ +/* + * Crash information logger + * Copyright (C) 2010 Felix Fietkau + * + * Based on ramoops.c + * Copyright (C) 2010 Marco Stornelli + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +#define CRASHLOG_PAGES 4 +#define CRASHLOG_SIZE (CRASHLOG_PAGES * PAGE_SIZE) +#define CRASHLOG_MAGIC 0xa1eedead + +/* + * Start the log at 1M before the end of RAM, as some boot loaders like + * to use the end of the RAM for stack usage and other things + * If this fails, fall back to using the last part. + */ +#define CRASHLOG_OFFSET (1024 * 1024) + +struct crashlog_data { + u32 magic; + u32 len; + u8 data[]; +}; + +static struct debugfs_blob_wrapper crashlog_blob; +static unsigned long crashlog_addr = 0; +static struct crashlog_data *crashlog_buf; +static struct kmsg_dumper dump; +static bool first = true; + +extern struct list_head *crashlog_modules; + +void __init crashlog_init_mem(bootmem_data_t *bdata) +{ + unsigned long addr; + + if (crashlog_addr) + return; + + addr = PFN_PHYS(bdata->node_low_pfn) - CRASHLOG_OFFSET; + if (reserve_bootmem(addr, CRASHLOG_SIZE, BOOTMEM_EXCLUSIVE) < 0) { + printk("Crashlog failed to allocate RAM at address 0x%lx\n", addr); + bdata->node_low_pfn -= CRASHLOG_PAGES; + addr = PFN_PHYS(bdata->node_low_pfn); + } + crashlog_addr = addr; +} + +static void __init crashlog_copy(void) +{ + if (crashlog_buf->magic != CRASHLOG_MAGIC) + return; + + if (!crashlog_buf->len || crashlog_buf->len > + CRASHLOG_SIZE - sizeof(*crashlog_buf)) + return; + + crashlog_blob.size = crashlog_buf->len; + crashlog_blob.data = kmemdup(crashlog_buf->data, + crashlog_buf->len, GFP_KERNEL); + + debugfs_create_blob("crashlog", 0700, NULL, &crashlog_blob); +} + +static int get_maxlen(void) +{ + return CRASHLOG_SIZE - sizeof(*crashlog_buf) - crashlog_buf->len; +} + +static void crashlog_printf(const char *fmt, ...) +{ + va_list args; + int len = get_maxlen(); + + if (!len) + return; + + va_start(args, fmt); + crashlog_buf->len += vsnprintf( + &crashlog_buf->data[crashlog_buf->len], + len, fmt, args); + va_end(args); +} + +static void crashlog_do_dump(struct kmsg_dumper *dumper, + enum kmsg_dump_reason reason, const char *s1, unsigned long l1, + const char *s2, unsigned long l2) +{ + unsigned long s1_start, s2_start; + unsigned long l1_cpy, l2_cpy; + struct timeval tv; + struct module *m; + char *buf; + int len; + + if (!first) + crashlog_printf("\n===================================\n"); + + do_gettimeofday(&tv); + crashlog_printf("Time: %lu.%lu\n", + (long)tv.tv_sec, (long)tv.tv_usec); + + if (first) { + crashlog_printf("Modules:"); + list_for_each_entry(m, crashlog_modules, list) { + crashlog_printf("\t%s@%p+%x", m->name, + m->module_core, m->core_size, + m->module_init, m->init_size); + } + crashlog_printf("\n"); + first = false; + } + + buf = (char *)&crashlog_buf->data[crashlog_buf->len]; + len = get_maxlen(); + + l2_cpy = min(l2, (unsigned long)len); + l1_cpy = min(l1, (unsigned long)len - l2_cpy); + + s2_start = l2 - l2_cpy; + s1_start = l1 - l1_cpy; + + memcpy(buf, s1 + s1_start, l1_cpy); + memcpy(buf + l1_cpy, s2 + s2_start, l2_cpy); + crashlog_buf->len += l1_cpy + l2_cpy; +} + + +int __init crashlog_init_fs(void) +{ + if (!crashlog_addr) + return -ENOMEM; + + crashlog_buf = ioremap(crashlog_addr, CRASHLOG_SIZE); + + crashlog_copy(); + + crashlog_buf->magic = CRASHLOG_MAGIC; + crashlog_buf->len = 0; + + dump.dump = crashlog_do_dump; + kmsg_dump_register(&dump); + + return 0; +} +module_init(crashlog_init_fs);