[PATCH v7 07/18] printk: Introduce kmsg_dump_reason_str()

From: Kees Cook
Date: Sun May 10 2020 - 16:25:01 EST


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>
---
fs/pstore/platform.c | 22 +---------------------
include/linux/kmsg_dump.h | 7 +++++++
kernel/printk/printk.c | 21 +++++++++++++++++++++
3 files changed, 29 insertions(+), 21 deletions(-)

diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c
index 90d146fbc7d2..a9e297eefdff 100644
--- a/fs/pstore/platform.c
+++ b/fs/pstore/platform.c
@@ -135,26 +135,6 @@ enum pstore_type_id pstore_name_to_type(const char *name)
}
EXPORT_SYMBOL_GPL(pstore_name_to_type);

-static const char *get_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";
- }
-}
-
static void pstore_timer_kick(void)
{
if (pstore_update_ms < 0)
@@ -407,7 +387,7 @@ static void pstore_dump(struct kmsg_dumper *dumper,
unsigned int part = 1;
int ret;

- why = get_reason_str(reason);
+ why = kmsg_dump_reason_str(reason);

if (down_trylock(&psinfo->buf_lock)) {
/* Failed to acquire lock: give up if we cannot wait. */
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