tools: kwboot: Replace fstat()+st_size by lseek()+SEEK_END
fstat()'s st_size works only for regular files. lseek() with SEEK_END works
also for block or MTD devices. This replacement allows kwboot to load
kwbimage from /dev/mtd0 for booting another device over /dev/ttyS0.
Signed-off-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Marek Behún <marek.behun@nic.cz>
diff --git a/tools/kwboot.c b/tools/kwboot.c
index 9f2dd2d..b697d3b 100644
--- a/tools/kwboot.c
+++ b/tools/kwboot.c
@@ -1591,8 +1591,8 @@
kwboot_read_image(const char *path, size_t *size, size_t reserve)
{
int rc, fd;
- struct stat st;
void *img;
+ off_t len;
off_t tot;
rc = -1;
@@ -1602,31 +1602,34 @@
if (fd < 0)
goto out;
- rc = fstat(fd, &st);
- if (rc)
+ len = lseek(fd, 0, SEEK_END);
+ if (len == (off_t)-1)
goto out;
- img = malloc(st.st_size + reserve);
+ if (lseek(fd, 0, SEEK_SET) == (off_t)-1)
+ goto out;
+
+ img = malloc(len + reserve);
if (!img)
goto out;
tot = 0;
- while (tot < st.st_size) {
- ssize_t rd = read(fd, img + tot, st.st_size - tot);
+ while (tot < len) {
+ ssize_t rd = read(fd, img + tot, len - tot);
if (rd < 0)
goto out;
tot += rd;
- if (!rd && tot < st.st_size) {
+ if (!rd && tot < len) {
errno = EIO;
goto out;
}
}
rc = 0;
- *size = st.st_size;
+ *size = len;
out:
if (rc && img) {
free(img);