[PATCH v6 07/18] printk: Introduce kmsg_dump_reason_str()

[Kees Cook]

The pstore subsystem already had a private version of this function.
With the coming addition of the pstore/zone driver, this needs to be
shared. As it really should live with printk, move it there instead.

Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
---
 include/linux/kmsg_dump.h |  7 +++++++
 kernel/printk/printk.c    | 21 +++++++++++++++++++++
 2 files changed, 28 insertions(+)

diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
index cfc042066be7..b3ddb0b2ee40 100644
--- a/include/linux/kmsg_dump.h
+++ b/include/linux/kmsg_dump.h
@@ -72,6 +72,8 @@ void kmsg_dump_rewind(struct kmsg_dumper *dumper);
 int kmsg_dump_register(struct kmsg_dumper *dumper);
 
 int kmsg_dump_unregister(struct kmsg_dumper *dumper);
+
+const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason);
 #else
 static inline void kmsg_dump(enum kmsg_dump_reason reason)
 {
@@ -113,6 +115,11 @@ static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper)
 {
 	return -EINVAL;
 }
+
+static inline const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason)
+{
+	return "Disabled";
+}
 #endif
 
 #endif /* _LINUX_KMSG_DUMP_H */
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 1aab69a8a2bf..67a284830d74 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -3144,6 +3144,27 @@ EXPORT_SYMBOL_GPL(kmsg_dump_unregister);
 static bool always_kmsg_dump;
 module_param_named(always_kmsg_dump, always_kmsg_dump, bool, S_IRUGO | S_IWUSR);
 
+const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason)
+{
+	switch (reason) {
+	case KMSG_DUMP_PANIC:
+		return "Panic";
+	case KMSG_DUMP_OOPS:
+		return "Oops";
+	case KMSG_DUMP_EMERG:
+		return "Emergency";
+	case KMSG_DUMP_RESTART:
+		return "Restart";
+	case KMSG_DUMP_HALT:
+		return "Halt";
+	case KMSG_DUMP_POWEROFF:
+		return "Poweroff";
+	default:
+		return "Unknown";
+	}
+}
+EXPORT_SYMBOL_GPL(kmsg_dump_reason_str);
+
 /**
  * kmsg_dump - dump kernel log to kernel message dumpers.
  * @reason: the reason (oops, panic etc) for dumping
-- 
2.20.1