The mkcksum() function now takes one parameter, the pointer to
11-byte wide character array, which it then operates on.
Currently, the function is wrongly passed (dir_entry)->name, which
is only 8-byte wide character array. Though by further inspecting
the dir_entry structure, it can be noticed that the name[8] entry
is immediatelly followed by ext[3] entry. Thus, name[8] and ext[3]
in the dir_entry structure actually work as this 11-byte wide array
since they're placed right next to each other by current compiler
behavior.
Depending on this is obviously wrong, thus fix this by correctly
passing both (dir_entry)->name and (dir_entry)->ext to the mkcksum()
function and adjust the function appropriately.
Signed-off-by: Marek Vasut <ma...@denx.de>
Cc: Tom Rini <tr...@ti.com>
---
fs/fat/fat.c | 20 ++++++++++++--------
fs/fat/fat_write.c | 2 +-
2 files changed, 13 insertions(+), 9 deletions(-)
V2: Fix fat write by adding braces
diff --git a/fs/fat/fat.c b/fs/fat/fat.c
index 41ae15e..8870292 100644
--- a/fs/fat/fat.c
+++ b/fs/fat/fat.c
@@ -567,15 +567,16 @@ get_vfatname(fsdata *mydata, int curclust, __u8 *cluster,
}
/* Calculate short name checksum */
-static __u8 mkcksum(const char *str)
+static __u8 mkcksum(const char name[8], const char ext[3])
{
int i;
__u8 ret = 0;
- for (i = 0; i < 11; i++) {
- ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + str[i];
- }
+ for (i = 0; i < sizeof(name); i++)
+ ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + name[i];
+ for (i = 0; i < sizeof(ext); i++)
+ ret = (((ret & 1) << 7) | ((ret & 0xfe) >> 1)) + ext[i];
return ret;
}
@@ -678,7 +679,8 @@ static dir_entry *get_dentfromdir(fsdata *mydata, int
startsect,
return NULL;
}
#ifdef CONFIG_SUPPORT_VFAT
- if (dols && mkcksum(dentptr->name) == prevcksum) {
+ __u8 csum = mkcksum(dentptr->name, dentptr->ext);
+ if (dols && csum == prevcksum) {
prevcksum = 0xffff;
dentptr++;
continue;
@@ -946,13 +948,16 @@ do_fat_read_at(const char *filename, unsigned long pos,
void *buffer,
for (i = 0; i < DIRENTSPERBLOCK; i++) {
char s_name[14], l_name[VFAT_MAXLEN_BYTES];
+ __u8 csum;
l_name[0] = '\0';
if (dentptr->name[0] == DELETED_FLAG) {
dentptr++;
continue;
}
- if ((dentptr->attr & ATTR_VOLUME)) {
+
+ csum = mkcksum(dentptr->name, dentptr->ext);
+ if (dentptr->attr & ATTR_VOLUME) {
#ifdef CONFIG_SUPPORT_VFAT
if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
(dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
@@ -1015,8 +1020,7 @@ do_fat_read_at(const char *filename, unsigned long pos,
void *buffer,
goto exit;
}
#ifdef CONFIG_SUPPORT_VFAT
- else if (dols == LS_ROOT &&
- mkcksum(dentptr->name) == prevcksum) {
+ else if (dols == LS_ROOT && csum == prevcksum) {
prevcksum = 0xffff;
dentptr++;
continue;
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 5829adf..4a1bda0 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -335,7 +335,7 @@ fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const
char *l_name)
/* Get short file name and checksum value */
strncpy(s_name, (*dentptr)->name, 16);
- checksum = mkcksum(s_name);
+ checksum = mkcksum((*dentptr)->name, (*dentptr)->ext);
do {
memset(slotptr, 0x00, sizeof(dir_slot));
