[RFC][PATCH 07/14] printk: add kmsg_kmemdump_register

[Eugen Hristev <eugen.hristev@linaro.org>]

Add kmsg_kmemdump_register, which registers prb, log_buf and infos/descs
to kmemdump.
This will allow kmemdump to be able to dump specific log buffer areas on
demand.

Signed-off-by: Eugen Hristev <eugen.hristev@linaro.org>
---
 include/linux/kmsg_dump.h |  6 ++++++
 kernel/printk/printk.c    | 13 +++++++++++++
 2 files changed, 19 insertions(+)

diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
index 6055fc969877..cbe76c94710b 100644
--- a/include/linux/kmsg_dump.h
+++ b/include/linux/kmsg_dump.h
@@ -80,6 +80,8 @@ int kmsg_dump_register(struct kmsg_dumper *dumper);
 
 int kmsg_dump_unregister(struct kmsg_dumper *dumper);
 
+void kmsg_kmemdump_register(void);
+
 const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason);
 #else
 static inline void kmsg_dump_desc(enum kmsg_dump_reason reason, const char *desc)
@@ -112,6 +114,10 @@ static inline int kmsg_dump_unregister(struct kmsg_dumper *dumper)
 	return -EINVAL;
 }
 
+static inline void kmsg_kmemdump_register(void)
+{
+}
+
 static inline const char *kmsg_dump_reason_str(enum kmsg_dump_reason reason)
 {
 	return "Disabled";
diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c
index 057db78876cd..cf4aa86ef7af 100644
--- a/kernel/printk/printk.c
+++ b/kernel/printk/printk.c
@@ -48,6 +48,7 @@
 #include <linux/sched/clock.h>
 #include <linux/sched/debug.h>
 #include <linux/sched/task_stack.h>
+#include <linux/kmemdump.h>
 
 #include <linux/uaccess.h>
 #include <asm/sections.h>
@@ -4650,6 +4651,18 @@ int kmsg_dump_register(struct kmsg_dumper *dumper)
 }
 EXPORT_SYMBOL_GPL(kmsg_dump_register);
 
+void kmsg_kmemdump_register(void)
+{
+	kmemdump_register("log_buf", (void *)log_buf_addr_get(), log_buf_len_get());
+	kmemdump_register("prb", (void *)&prb, sizeof(prb));
+	kmemdump_register("prb", (void *)prb, sizeof(*prb));
+	kmemdump_register("prb_descs", (void *)_printk_rb_static_descs,
+			  sizeof(_printk_rb_static_descs));
+	kmemdump_register("prb_infos", (void *)_printk_rb_static_infos,
+			  sizeof(_printk_rb_static_infos));
+}
+EXPORT_SYMBOL_GPL(kmsg_kmemdump_register);
+
 /**
  * kmsg_dump_unregister - unregister a kmsg dumper.
  * @dumper: pointer to the kmsg_dumper structure
-- 
2.43.0