From: Łukasz Stelmach <l.stelmach@samsung.com>
Date: Thu, 16 Dec 2021 19:03:53 +0000 (+0100)
Subject: Replace copy_from_iter() with copy_from_user()
X-Git-Tag: submit/tizen/20220105.151434~1
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=a37083e376255e4a7eb4978f5d754eecba254f74;p=platform%2Fkernel%2Flinux-tizen-modules-source.git

Replace copy_from_iter() with copy_from_user()

iov_iter structure and associated function have been introduced in
v3.18. Logger needs use copy_from_user() and iterate over IO vectores
manualy.

Change-Id: Ifa46c67da65195611adc50b1dc6f0be66daac517
Signed-off-by: Łukasz Stelmach <l.stelmach@samsung.com>
---

diff --git a/kernel/logger.c b/kernel/logger.c
index 9dbe22a..4eb7103 100644
--- a/kernel/logger.c
+++ b/kernel/logger.c
@@ -623,7 +623,6 @@ 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)
@@ -651,6 +650,8 @@ static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		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;
+		/* offset in the *current* iov */
+		size_t iov_offset = 0;
 
 		if (writer->owner != current->group_leader) {
 			struct file *nfile;
@@ -680,19 +681,21 @@ static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
 		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),
+		c = min_t(size_t, iov->iov_len,
 			  max_payload - writer->b_off - 1);
 
 		do {
 			size_t i;
 
-			if (copy_from_iter(writer->buffer + writer->b_off, c, from) != c) {
+			if (copy_from_user(writer->buffer + writer->b_off, iov->iov_base + iov_offset, c)) {
 				mutex_unlock(&log->mutex);
 				return -EFAULT;
 			}
-			count += c;
+
+			ret += c;
+			iov_offset += c;
+
 			p = NULL;
 			for (i = 0; i < c; ++i) {
 				char *t = &writer->buffer[writer->b_off + i];
@@ -729,7 +732,14 @@ static ssize_t logger_aio_write(struct kiocb *iocb, const struct iovec *iov,
 			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)));
+			if (iov_offset >= iov->iov_len) {
+				WARN_ON(iov_offset > iov->iov_len);
+				nr_segs--;
+				iov++;
+				iov_offset = 0;
+			}
+
+		} while (nr_segs && (c = min_t(size_t, iov->iov_len - iov_offset, max_payload - 1)));
 
 		/* save for remaining unfinished line */
 		writer->b_header = header;