[6/8] mtd-utils: Fix "are we really at EOF" test logic in libubi read_data
diff mbox series

Message ID 20200128172715.19545-7-david.oberhollenzer@sigma-star.at
State New
Headers show
  • mtd-utils: fixes for various issues reported by static analysis
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Commit Message

David Oberhollenzer Jan. 28, 2020, 5:27 p.m. UTC
The function reads file data into a buffer and then checks if we
actually are at the end-of-file by trying to read one more byte.
For whatever reason, the code uses an int instead of a char. It's
not pretty but works. But again, this is something that every
static analysis tool barks at.

Further more, the error messages are inverted. "We aren't at EOF yet"
is printed on failure and something like "read error %m" is printed
on success.

This patch fixes all of the above.

Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
 lib/libubi.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff mbox series

diff --git a/lib/libubi.c b/lib/libubi.c
index aaeeb38..afe3648 100644
--- a/lib/libubi.c
+++ b/lib/libubi.c
@@ -156,7 +156,8 @@  static int read_positive_int(const char *file, int *value)
 static int read_data(const char *file, void *buf, int buf_len)
-	int fd, rd, tmp, tmp1;
+	int fd, rd, tmp1;
+	char tmp;
 	fd = open(file, O_RDONLY);
 	if (fd == -1)
@@ -178,11 +179,11 @@  static int read_data(const char *file, void *buf, int buf_len)
 	/* Make sure all data is read */
 	tmp1 = read(fd, &tmp, 1);
-	if (tmp1 == 1) {
+	if (tmp1 < 0) {
 		sys_errmsg("cannot read \"%s\"", file);
 		goto out_error;
-	if (tmp1) {
+	if (tmp1 > 0) {
 		errmsg("file \"%s\" contains too much data (> %d bytes)",
 		       file, buf_len);
 		errno = EINVAL;