mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2025-04-21 12:27:27 +03:00
kernel: add the new 'crashlog' feature, which tries to store kernel oops/panic logs in a fixed location in RAM to recover them after the reboot and make them available to user space using debugfs
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@22305 3c298f89-4303-0410-b956-a3cf2f4a3e73
This commit is contained in:
nbd
205
target/linux/generic/patches-2.6.32/930-kmsg_dump_backport.patch
Normal file
205
target/linux/generic/patches-2.6.32/930-kmsg_dump_backport.patch
Normal file
@@ -0,0 +1,205 @@
|
||||
--- /dev/null
|
||||
+++ b/include/linux/kmsg_dump.h
|
||||
@@ -0,0 +1,44 @@
|
||||
+/*
|
||||
+ * linux/include/kmsg_dump.h
|
||||
+ *
|
||||
+ * Copyright (C) 2009 Net Insight AB
|
||||
+ *
|
||||
+ * Author: Simon Kagstrom <simon.kagstrom@netinsight.net>
|
||||
+ *
|
||||
+ * This file is subject to the terms and conditions of the GNU General Public
|
||||
+ * License. See the file COPYING in the main directory of this archive
|
||||
+ * for more details.
|
||||
+ */
|
||||
+#ifndef _LINUX_KMSG_DUMP_H
|
||||
+#define _LINUX_KMSG_DUMP_H
|
||||
+
|
||||
+#include <linux/list.h>
|
||||
+
|
||||
+enum kmsg_dump_reason {
|
||||
+ KMSG_DUMP_OOPS,
|
||||
+ KMSG_DUMP_PANIC,
|
||||
+};
|
||||
+
|
||||
+/**
|
||||
+ * struct kmsg_dumper - kernel crash message dumper structure
|
||||
+ * @dump: The callback which gets called on crashes. The buffer is passed
|
||||
+ * as two sections, where s1 (length l1) contains the older
|
||||
+ * messages and s2 (length l2) contains the newer.
|
||||
+ * @list: Entry in the dumper list (private)
|
||||
+ * @registered: Flag that specifies if this is already registered
|
||||
+ */
|
||||
+struct kmsg_dumper {
|
||||
+ void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason,
|
||||
+ const char *s1, unsigned long l1,
|
||||
+ const char *s2, unsigned long l2);
|
||||
+ struct list_head list;
|
||||
+ int registered;
|
||||
+};
|
||||
+
|
||||
+void kmsg_dump(enum kmsg_dump_reason reason);
|
||||
+
|
||||
+int kmsg_dump_register(struct kmsg_dumper *dumper);
|
||||
+
|
||||
+int kmsg_dump_unregister(struct kmsg_dumper *dumper);
|
||||
+
|
||||
+#endif /* _LINUX_KMSG_DUMP_H */
|
||||
--- a/kernel/panic.c
|
||||
+++ b/kernel/panic.c
|
||||
@@ -10,6 +10,7 @@
|
||||
*/
|
||||
#include <linux/debug_locks.h>
|
||||
#include <linux/interrupt.h>
|
||||
+#include <linux/kmsg_dump.h>
|
||||
#include <linux/kallsyms.h>
|
||||
#include <linux/notifier.h>
|
||||
#include <linux/module.h>
|
||||
@@ -74,6 +75,7 @@ NORET_TYPE void panic(const char * fmt,
|
||||
dump_stack();
|
||||
#endif
|
||||
|
||||
+ kmsg_dump(KMSG_DUMP_PANIC);
|
||||
/*
|
||||
* If we have crashed and we have a crash kernel loaded let it handle
|
||||
* everything else.
|
||||
@@ -339,6 +341,7 @@ void oops_exit(void)
|
||||
{
|
||||
do_oops_enter_exit();
|
||||
print_oops_end_marker();
|
||||
+ kmsg_dump(KMSG_DUMP_OOPS);
|
||||
}
|
||||
|
||||
#ifdef WANT_WARN_ON_SLOWPATH
|
||||
--- a/kernel/printk.c
|
||||
+++ b/kernel/printk.c
|
||||
@@ -33,6 +33,7 @@
|
||||
#include <linux/bootmem.h>
|
||||
#include <linux/syscalls.h>
|
||||
#include <linux/kexec.h>
|
||||
+#include <linux/kmsg_dump.h>
|
||||
|
||||
#include <asm/uaccess.h>
|
||||
|
||||
@@ -1405,3 +1406,121 @@ bool printk_timed_ratelimit(unsigned lon
|
||||
}
|
||||
EXPORT_SYMBOL(printk_timed_ratelimit);
|
||||
#endif
|
||||
+
|
||||
+static DEFINE_SPINLOCK(dump_list_lock);
|
||||
+static LIST_HEAD(dump_list);
|
||||
+
|
||||
+/**
|
||||
+ * kmsg_dump_register - register a kernel log dumper.
|
||||
+ * @dump: pointer to the kmsg_dumper structure
|
||||
+ *
|
||||
+ * Adds a kernel log dumper to the system. The dump callback in the
|
||||
+ * structure will be called when the kernel oopses or panics and must be
|
||||
+ * set. Returns zero on success and %-EINVAL or %-EBUSY otherwise.
|
||||
+ */
|
||||
+int kmsg_dump_register(struct kmsg_dumper *dumper)
|
||||
+{
|
||||
+ unsigned long flags;
|
||||
+ int err = -EBUSY;
|
||||
+
|
||||
+ /* The dump callback needs to be set */
|
||||
+ if (!dumper->dump)
|
||||
+ return -EINVAL;
|
||||
+
|
||||
+ spin_lock_irqsave(&dump_list_lock, flags);
|
||||
+ /* Don't allow registering multiple times */
|
||||
+ if (!dumper->registered) {
|
||||
+ dumper->registered = 1;
|
||||
+ list_add_tail(&dumper->list, &dump_list);
|
||||
+ err = 0;
|
||||
+ }
|
||||
+ spin_unlock_irqrestore(&dump_list_lock, flags);
|
||||
+
|
||||
+ return err;
|
||||
+}
|
||||
+EXPORT_SYMBOL_GPL(kmsg_dump_register);
|
||||
+
|
||||
+/**
|
||||
+ * kmsg_dump_unregister - unregister a kmsg dumper.
|
||||
+ * @dump: pointer to the kmsg_dumper structure
|
||||
+ *
|
||||
+ * Removes a dump device from the system. Returns zero on success and
|
||||
+ * %-EINVAL otherwise.
|
||||
+ */
|
||||
+int kmsg_dump_unregister(struct kmsg_dumper *dumper)
|
||||
+{
|
||||
+ unsigned long flags;
|
||||
+ int err = -EINVAL;
|
||||
+
|
||||
+ spin_lock_irqsave(&dump_list_lock, flags);
|
||||
+ if (dumper->registered) {
|
||||
+ dumper->registered = 0;
|
||||
+ list_del(&dumper->list);
|
||||
+ err = 0;
|
||||
+ }
|
||||
+ spin_unlock_irqrestore(&dump_list_lock, flags);
|
||||
+
|
||||
+ return err;
|
||||
+}
|
||||
+EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
|
||||
+
|
||||
+static const char const *kmsg_reasons[] = {
|
||||
+ [KMSG_DUMP_OOPS] = "oops",
|
||||
+ [KMSG_DUMP_PANIC] = "panic",
|
||||
+};
|
||||
+
|
||||
+static const char *kmsg_to_str(enum kmsg_dump_reason reason)
|
||||
+{
|
||||
+ if (reason >= ARRAY_SIZE(kmsg_reasons) || reason < 0)
|
||||
+ return "unknown";
|
||||
+
|
||||
+ return kmsg_reasons[reason];
|
||||
+}
|
||||
+
|
||||
+/**
|
||||
+ * kmsg_dump - dump kernel log to kernel message dumpers.
|
||||
+ * @reason: the reason (oops, panic etc) for dumping
|
||||
+ *
|
||||
+ * Iterate through each of the dump devices and call the oops/panic
|
||||
+ * callbacks with the log buffer.
|
||||
+ */
|
||||
+void kmsg_dump(enum kmsg_dump_reason reason)
|
||||
+{
|
||||
+ unsigned long end;
|
||||
+ unsigned chars;
|
||||
+ struct kmsg_dumper *dumper;
|
||||
+ const char *s1, *s2;
|
||||
+ unsigned long l1, l2;
|
||||
+ unsigned long flags;
|
||||
+
|
||||
+ /* Theoretically, the log could move on after we do this, but
|
||||
+ there's not a lot we can do about that. The new messages
|
||||
+ will overwrite the start of what we dump. */
|
||||
+ spin_lock_irqsave(&logbuf_lock, flags);
|
||||
+ end = log_end & LOG_BUF_MASK;
|
||||
+ chars = logged_chars;
|
||||
+ spin_unlock_irqrestore(&logbuf_lock, flags);
|
||||
+
|
||||
+ if (logged_chars > end) {
|
||||
+ s1 = log_buf + log_buf_len - logged_chars + end;
|
||||
+ l1 = logged_chars - end;
|
||||
+
|
||||
+ s2 = log_buf;
|
||||
+ l2 = end;
|
||||
+ } else {
|
||||
+ s1 = "";
|
||||
+ l1 = 0;
|
||||
+
|
||||
+ s2 = log_buf + end - logged_chars;
|
||||
+ l2 = logged_chars;
|
||||
+ }
|
||||
+
|
||||
+ if (!spin_trylock_irqsave(&dump_list_lock, flags)) {
|
||||
+ printk(KERN_ERR "dump_kmsg: dump list lock is held during %s, skipping dump\n",
|
||||
+ kmsg_to_str(reason));
|
||||
+ return;
|
||||
+ }
|
||||
+ list_for_each_entry(dumper, &dump_list, list)
|
||||
+ dumper->dump(dumper, reason, s1, l1, s2, l2);
|
||||
+ spin_unlock_irqrestore(&dump_list_lock, flags);
|
||||
+}
|
||||
Reference in New Issue
Block a user