mirror of
git://projects.qi-hardware.com/openwrt-xburst.git
synced 2024-09-12 17:02:05 +03:00
git-svn-id: svn://svn.openwrt.org/openwrt/trunk@26124 3c298f89-4303-0410-b956-a3cf2f4a3e73
206 lines
5.2 KiB
Diff
206 lines
5.2 KiB
Diff
--- /dev/null
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+++ b/include/linux/kmsg_dump.h
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@@ -0,0 +1,44 @@
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+/*
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+ * linux/include/kmsg_dump.h
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+ *
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+ * Copyright (C) 2009 Net Insight AB
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+ *
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+ * Author: Simon Kagstrom <simon.kagstrom@netinsight.net>
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+ *
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+ * This file is subject to the terms and conditions of the GNU General Public
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+ * License. See the file COPYING in the main directory of this archive
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+ * for more details.
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+ */
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+#ifndef _LINUX_KMSG_DUMP_H
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+#define _LINUX_KMSG_DUMP_H
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+
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+#include <linux/list.h>
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+
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+enum kmsg_dump_reason {
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+ KMSG_DUMP_OOPS,
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+ KMSG_DUMP_PANIC,
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+};
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+
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+/**
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+ * struct kmsg_dumper - kernel crash message dumper structure
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+ * @dump: The callback which gets called on crashes. The buffer is passed
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+ * as two sections, where s1 (length l1) contains the older
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+ * messages and s2 (length l2) contains the newer.
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+ * @list: Entry in the dumper list (private)
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+ * @registered: Flag that specifies if this is already registered
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+ */
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+struct kmsg_dumper {
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+ void (*dump)(struct kmsg_dumper *dumper, enum kmsg_dump_reason reason,
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+ const char *s1, unsigned long l1,
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+ const char *s2, unsigned long l2);
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+ struct list_head list;
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+ int registered;
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+};
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+
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+void kmsg_dump(enum kmsg_dump_reason reason);
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+
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+int kmsg_dump_register(struct kmsg_dumper *dumper);
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+
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+int kmsg_dump_unregister(struct kmsg_dumper *dumper);
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+
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+#endif /* _LINUX_KMSG_DUMP_H */
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--- a/kernel/panic.c
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+++ b/kernel/panic.c
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@@ -10,6 +10,7 @@
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*/
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#include <linux/debug_locks.h>
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#include <linux/interrupt.h>
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+#include <linux/kmsg_dump.h>
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#include <linux/kallsyms.h>
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#include <linux/notifier.h>
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#include <linux/module.h>
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@@ -74,6 +75,7 @@ NORET_TYPE void panic(const char * fmt,
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dump_stack();
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#endif
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+ kmsg_dump(KMSG_DUMP_PANIC);
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/*
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* If we have crashed and we have a crash kernel loaded let it handle
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* everything else.
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@@ -339,6 +341,7 @@ void oops_exit(void)
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{
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do_oops_enter_exit();
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print_oops_end_marker();
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+ kmsg_dump(KMSG_DUMP_OOPS);
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}
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#ifdef WANT_WARN_ON_SLOWPATH
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--- a/kernel/printk.c
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+++ b/kernel/printk.c
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@@ -33,6 +33,7 @@
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#include <linux/bootmem.h>
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#include <linux/syscalls.h>
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#include <linux/kexec.h>
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+#include <linux/kmsg_dump.h>
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#include <asm/uaccess.h>
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@@ -1407,3 +1408,121 @@ bool printk_timed_ratelimit(unsigned lon
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}
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EXPORT_SYMBOL(printk_timed_ratelimit);
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#endif
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+
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+static DEFINE_SPINLOCK(dump_list_lock);
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+static LIST_HEAD(dump_list);
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+
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+/**
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+ * kmsg_dump_register - register a kernel log dumper.
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+ * @dump: pointer to the kmsg_dumper structure
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+ *
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+ * Adds a kernel log dumper to the system. The dump callback in the
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+ * structure will be called when the kernel oopses or panics and must be
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+ * set. Returns zero on success and %-EINVAL or %-EBUSY otherwise.
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+ */
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+int kmsg_dump_register(struct kmsg_dumper *dumper)
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+{
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+ unsigned long flags;
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+ int err = -EBUSY;
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+
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+ /* The dump callback needs to be set */
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+ if (!dumper->dump)
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+ return -EINVAL;
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+
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+ spin_lock_irqsave(&dump_list_lock, flags);
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+ /* Don't allow registering multiple times */
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+ if (!dumper->registered) {
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+ dumper->registered = 1;
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+ list_add_tail(&dumper->list, &dump_list);
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+ err = 0;
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+ }
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+ spin_unlock_irqrestore(&dump_list_lock, flags);
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+
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+ return err;
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+}
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+EXPORT_SYMBOL_GPL(kmsg_dump_register);
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+
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+/**
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+ * kmsg_dump_unregister - unregister a kmsg dumper.
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+ * @dump: pointer to the kmsg_dumper structure
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+ *
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+ * Removes a dump device from the system. Returns zero on success and
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+ * %-EINVAL otherwise.
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+ */
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+int kmsg_dump_unregister(struct kmsg_dumper *dumper)
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+{
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+ unsigned long flags;
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+ int err = -EINVAL;
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+
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+ spin_lock_irqsave(&dump_list_lock, flags);
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+ if (dumper->registered) {
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+ dumper->registered = 0;
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+ list_del(&dumper->list);
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+ err = 0;
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+ }
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+ spin_unlock_irqrestore(&dump_list_lock, flags);
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+
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+ return err;
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+}
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+EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
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+
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+static const char const *kmsg_reasons[] = {
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+ [KMSG_DUMP_OOPS] = "oops",
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+ [KMSG_DUMP_PANIC] = "panic",
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+};
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+
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+static const char *kmsg_to_str(enum kmsg_dump_reason reason)
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+{
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+ if (reason >= ARRAY_SIZE(kmsg_reasons) || reason < 0)
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+ return "unknown";
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+
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+ return kmsg_reasons[reason];
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+}
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+
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+/**
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+ * kmsg_dump - dump kernel log to kernel message dumpers.
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+ * @reason: the reason (oops, panic etc) for dumping
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+ *
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+ * Iterate through each of the dump devices and call the oops/panic
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+ * callbacks with the log buffer.
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+ */
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+void kmsg_dump(enum kmsg_dump_reason reason)
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+{
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+ unsigned long end;
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+ unsigned chars;
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+ struct kmsg_dumper *dumper;
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+ const char *s1, *s2;
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+ unsigned long l1, l2;
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+ unsigned long flags;
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+
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+ /* Theoretically, the log could move on after we do this, but
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+ there's not a lot we can do about that. The new messages
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+ will overwrite the start of what we dump. */
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+ spin_lock_irqsave(&logbuf_lock, flags);
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+ end = log_end & LOG_BUF_MASK;
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+ chars = logged_chars;
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+ spin_unlock_irqrestore(&logbuf_lock, flags);
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+
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+ if (logged_chars > end) {
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+ s1 = log_buf + log_buf_len - logged_chars + end;
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+ l1 = logged_chars - end;
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+
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+ s2 = log_buf;
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+ l2 = end;
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+ } else {
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+ s1 = "";
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+ l1 = 0;
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+
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+ s2 = log_buf + end - logged_chars;
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+ l2 = logged_chars;
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+ }
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+
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+ if (!spin_trylock_irqsave(&dump_list_lock, flags)) {
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+ printk(KERN_ERR "dump_kmsg: dump list lock is held during %s, skipping dump\n",
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+ kmsg_to_str(reason));
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+ return;
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+ }
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+ list_for_each_entry(dumper, &dump_list, list)
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+ dumper->dump(dumper, reason, s1, l1, s2, l2);
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+ spin_unlock_irqrestore(&dump_list_lock, flags);
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+}
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