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 --- tools/kwboot.c | 19 +++++++++++-------- 1 file changed, 11 insertions(+), 8 deletions(-)
diff --git a/tools/kwboot.c b/tools/kwboot.c index 9f2dd2de4ef5..b697d3b60e6a 100644 --- a/tools/kwboot.c +++ b/tools/kwboot.c @@ -1591,8 +1591,8 @@ static void * 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 @@ kwboot_read_image(const char *path, size_t *size, size_t reserve) if (fd < 0) goto out;
- rc = fstat(fd, &st); - if (rc) + len = lseek(fd, 0, SEEK_END); + if (len == (off_t)-1) + goto out; + + if (lseek(fd, 0, SEEK_SET) == (off_t)-1) goto out;
- img = malloc(st.st_size + reserve); + 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);