From 572e0596e94f8c8692ef6f345b2aa28112972fb0 Mon Sep 17 00:00:00 2001
From: =?utf8?q?=C5=81ukasz=20Stelmach?= <l.stelmach@samsung.com>
Date: Thu, 16 Dec 2021 00:32:13 +0100
Subject: [PATCH] Import stdio handling code to logger_aio_write()
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Copy the stdio handling code from logger_write_iter()

Change-Id: I94be88c5db2e7482106ddd537d763726a89aad5a
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---
 kernel/logger.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 88 insertions(+), 1 deletion(-)

diff --git a/kernel/logger.c b/kernel/logger.c
index b5a8d2b..9dbe22a 100644
--- a/kernel/logger.c
+++ b/kernel/logger.c
@@ -623,6 +623,7 @@ static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
 	struct logger_entry header;
 	struct timespec now;
 	ssize_t ret = 0;
+	size_t count;
 	bool from_stdio = false;
 
 	if (writer->tag && writer->prio >= 2)
@@ -646,7 +647,93 @@ static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
 
 	/* Prepend messages from STDOUT and STDERR with a tag and prio */
 	if (from_stdio) {
-		return 0;
+		char *p;
+		size_t chunk_len = 0, c = 0;
+		/* -2 : priority byte and tag terminating '\0' */
+		size_t max_payload = LOGGER_ENTRY_MAX_PAYLOAD - writer->tag_len - 2;
+
+		if (writer->owner != current->group_leader) {
+			struct file *nfile;
+
+			nfile = make_new_file(file);
+			if (IS_ERR(nfile)) {
+				mutex_unlock(&log->mutex);
+				return PTR_ERR(nfile);
+			}
+
+			file = nfile;
+			writer = file->private_data;
+		}
+
+		/* Allocate STDIO line buffer */
+		if (!writer->buffer) {
+			writer->buffer = kzalloc(LOGGER_ENTRY_MAX_PAYLOAD, GFP_KERNEL);
+			writer->b_off = 0;
+
+			if (!writer->buffer) {
+				mutex_unlock(&log->mutex);
+				return -ENOMEM;
+			}
+		}
+
+		/* flush message from a different thread */
+		if (writer->b_owner != current && writer->b_off)
+			flush_thread_data(file);
+
+		count = 0;
+		/* -1 : leave space for message terminating '\0' */
+		c = min_t(size_t, iov_iter_count(from),
+			  max_payload - writer->b_off - 1);
+
+		do {
+			size_t i;
+
+			if (copy_from_iter(writer->buffer + writer->b_off, c, from) != c) {
+				mutex_unlock(&log->mutex);
+				return -EFAULT;
+			}
+			count += c;
+			p = NULL;
+			for (i = 0; i < c; ++i) {
+				char *t = &writer->buffer[writer->b_off + i];
+				if (*t == '\0')
+					*t = '\n';
+				if (*t == '\n')
+					p = t;
+			}
+			if (p) {
+				*p++ = '\0';
+				chunk_len = p - writer->buffer;
+			} else {
+				writer->buffer[writer->b_off + c++] = '\0';
+				p = &writer->buffer[writer->b_off + c];
+				chunk_len = p - writer->buffer;
+
+				BUG_ON(chunk_len > max_payload);
+				if (chunk_len < max_payload ) {
+					writer->b_off = writer->b_off + c - 1;
+					continue;
+				}
+
+			}
+
+			header.len = chunk_len + writer->tag_len + 2;
+			fix_up_readers(log, sizeof(struct logger_entry) + header.len);
+
+			write_log_data(log, &header, writer, chunk_len);
+
+			/* move the remaining part of the message */
+			memmove(writer->buffer, p, writer->b_off + c - chunk_len);
+
+			/* new b_off points where the rimainder of the string ends */
+			writer->b_off = writer->b_off + c - chunk_len;
+			writer->buffer[writer->b_off] = '\0';
+
+		} while ((c = min_t(size_t, iov_iter_count(from), max_payload - 1)));
+
+		/* save for remaining unfinished line */
+		writer->b_header = header;
+		writer->b_owner = current;
 	} else {
 		orig = log->w_off;
 
-- 
2.34.1