Add some clarity to the printk subsystem by restructuring
the code a bit.
Move the kmsg variables and functions to a separate
code file.
Signed-off-by: Joe Perches <joe@xxxxxxxxxxx>
---
kernel/printk/Makefile | 1 +
kernel/printk/kmsg.c | 114 ++++++++++++++++++++++++++++++++++++++++++++++++
kernel/printk/printk.c | 107 ---------------------------------------------
3 files changed, 115 insertions(+), 107 deletions(-)
create mode 100644 kernel/printk/kmsg.c
diff --git a/kernel/printk/Makefile b/kernel/printk/Makefile
index 28b7129..396e085 100644
--- a/kernel/printk/Makefile
+++ b/kernel/printk/Makefile
@@ -1,3 +1,4 @@
obj-y += printk.o
obj-y += log_buf.o
obj-y += console.o
+obj-y += kmsg.o
diff --git a/kernel/printk/kmsg.c b/kernel/printk/kmsg.c
new file mode 100644
index 0000000..ce64242
--- /dev/null
+++ b/kernel/printk/kmsg.c
@@ -0,0 +1,114 @@
+#include <linux/kernel.h>
+#include <linux/nmi.h>
+#include <linux/module.h>
+#include <linux/kmsg_dump.h>
+
+#include "log_buf.h"
+
+static bool always_kmsg_dump;
+module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
+
+static DEFINE_SPINLOCK(dump_list_lock);
+static LIST_HEAD(dump_list);
+
+/**
+ * kmsg_dump_register - register a kernel log dumper.
+ * @dumper: 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_rcu(&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.
+ * @dumper: 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_rcu(&dumper->list);
+ err = 0;
+ }
+ spin_unlock_irqrestore(&dump_list_lock, flags);
+ synchronize_rcu();
+
+ return err;
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
+
+/**
+ * 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;
+
+ if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
+ return;
+
+ /* 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. */
+ raw_spin_lock_irqsave(&logbuf_lock, flags);
+ end = log_end & LOG_BUF_MASK;
+ chars = logged_chars;
+ raw_spin_unlock_irqrestore(&logbuf_lock, flags);
+
+ if (chars > end) {
+ s1 = log_buf + log_buf_len - chars + end;
+ l1 = chars - end;
+
+ s2 = log_buf;
+ l2 = end;
+ } else {
+ s1 = "";
+ l1 = 0;
+
+ s2 = log_buf + end - chars;
+ l2 = chars;
+ }
+
+ rcu_read_lock();
+ list_for_each_entry_rcu(dumper, &dump_list, list)
+ dumper->dump(dumper, reason, s1, l1, s2, l2);
+ rcu_read_unlock();
+}
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 3281441..aff4563 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -288,9 +288,6 @@ static bool printk_time = 0;
#endif
module_param_named(time, printk_time, bool, S_IRUGO | S_IWUSR);
-static bool always_kmsg_dump;
-module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
-
/**
* printk - print a kernel message
* @fmt: format string
@@ -623,108 +620,4 @@ bool printk_timed_ratelimit(unsigned long *caller_jiffies,
}
EXPORT_SYMBOL(printk_timed_ratelimit);
-static DEFINE_SPINLOCK(dump_list_lock);
-static LIST_HEAD(dump_list);
-
-/**
- * kmsg_dump_register - register a kernel log dumper.
- * @dumper: 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_rcu(&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.
- * @dumper: 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_rcu(&dumper->list);
- err = 0;
- }
- spin_unlock_irqrestore(&dump_list_lock, flags);
- synchronize_rcu();
-
- return err;
-}
-EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
-
-/**
- * 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;
-
- if ((reason > KMSG_DUMP_OOPS) && !always_kmsg_dump)
- return;
-
- /* 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. */
- raw_spin_lock_irqsave(&logbuf_lock, flags);
- end = log_end & LOG_BUF_MASK;
- chars = logged_chars;
- raw_spin_unlock_irqrestore(&logbuf_lock, flags);
-
- if (chars > end) {
- s1 = log_buf + log_buf_len - chars + end;
- l1 = chars - end;
-
- s2 = log_buf;
- l2 = end;
- } else {
- s1 = "";
- l1 = 0;
-
- s2 = log_buf + end - chars;
- l2 = chars;
- }
-
- rcu_read_lock();
- list_for_each_entry_rcu(dumper, &dump_list, list)
- dumper->dump(dumper, reason, s1, l1, s2, l2);
- rcu_read_unlock();
-}
#endif
--
1.7.8.111.gad25c.dirty
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