printk: Implement some unlocked kmsg_dump functions
If used from KDB, the locked variants are prone to deadlocks (suppose we
got to the debugger w/ the logbuf lock held).
So, we have to implement a few routines that grab no logbuf lock.
Yet we don't need these functions in modules, so we don't export them.
Signed-off-by: Anton Vorontsov <anton.vorontsov@linaro.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/kmsg_dump.h b/include/linux/kmsg_dump.h
index d6bd501..2e7a1e0 100644
--- a/include/linux/kmsg_dump.h
+++ b/include/linux/kmsg_dump.h
@@ -55,12 +55,17 @@
#ifdef CONFIG_PRINTK
void kmsg_dump(enum kmsg_dump_reason reason);
+bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper, bool syslog,
+ char *line, size_t size, size_t *len);
+
bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
char *line, size_t size, size_t *len);
bool kmsg_dump_get_buffer(struct kmsg_dumper *dumper, bool syslog,
char *buf, size_t size, size_t *len);
+void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper);
+
void kmsg_dump_rewind(struct kmsg_dumper *dumper);
int kmsg_dump_register(struct kmsg_dumper *dumper);
@@ -71,6 +76,13 @@
{
}
+static inline bool kmsg_dump_get_line_nolock(struct kmsg_dumper *dumper,
+ bool syslog, const char *line,
+ size_t size, size_t *len)
+{
+ return false;
+}
+
static inline bool kmsg_dump_get_line(struct kmsg_dumper *dumper, bool syslog,
const char *line, size_t size, size_t *len)
{
@@ -83,6 +95,10 @@
return false;
}
+static inline void kmsg_dump_rewind_nolock(struct kmsg_dumper *dumper)
+{
+}
+
static inline void kmsg_dump_rewind(struct kmsg_dumper *dumper)
{
}