ANDROID: logbuf: Add new logbuf vendor hook to support pr_cont()

Add new logbuf vendor hook android_vh_logbuf_pr_cont()
to capture pr_cont logs.

Bug: 185182649
Change-Id: I76b310fc9caac71b344b6cc25ea36f7f81cb7148
Signed-off-by: Mukesh Ojha <mojha@codeaurora.org>

drivers/android/vendor_hooks.c

@@ -271,6 +271,7 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(android_rvh_post_init_entity_util_avg);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_typec_tcpm_get_timer);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_typec_tcpm_adj_current_limit);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_logbuf);
+EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_logbuf_pr_cont);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tune_scan_type);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_tune_swappiness);
 EXPORT_TRACEPOINT_SYMBOL_GPL(android_vh_shrink_slab_bypass);

include/trace/hooks/logbuf.h

@@ -17,6 +17,10 @@ struct printk_record;
 DECLARE_HOOK(android_vh_logbuf,
 	TP_PROTO(struct printk_ringbuffer *rb, struct printk_record *r),
 	TP_ARGS(rb, r))
+
+DECLARE_HOOK(android_vh_logbuf_pr_cont,
+	TP_PROTO(struct printk_record *r, size_t text_len),
+	TP_ARGS(r, text_len))
 #else
 #define trace_android_vh_logbuf(rb, r)
 #endif

kernel/printk/printk.c

@@ -1958,6 +1958,8 @@ static size_t log_output(int facility, int level, enum log_flags lflags,
 			} else {
 				prb_commit(&e);
 			}
+
+			trace_android_vh_logbuf_pr_cont(&r, text_len);
 			return text_len;
 		}
 	}