On 3/21/2022 8:30 AM, Paulo Alcantara wrote:
Tom Talpey <tom@xxxxxxxxxx> writes:
On 3/20/2022 8:20 PM, Paulo Alcantara wrote:
The client used to partially convert the fids to le64, while storing
or sending them by using host endianness. This broke the client on
big-endian machines. Instead of converting them to le64, store them
verbatim and then avoid byteswapping when sending them over wire.
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxx>
---
fs/cifs/smb2misc.c | 4 ++--
fs/cifs/smb2ops.c | 8 +++----
fs/cifs/smb2pdu.c | 53 ++++++++++++++++++++--------------------------
3 files changed, 29 insertions(+), 36 deletions(-)
diff --git a/fs/cifs/smb2misc.c b/fs/cifs/smb2misc.c
index b25623e3fe3d..3b7c636be377 100644
--- a/fs/cifs/smb2misc.c
+++ b/fs/cifs/smb2misc.c
@@ -832,8 +832,8 @@ smb2_handle_cancelled_mid(struct mid_q_entry *mid, struct TCP_Server_Info *serve
rc = __smb2_handle_cancelled_cmd(tcon,
le16_to_cpu(hdr->Command),
le64_to_cpu(hdr->MessageId),
- le64_to_cpu(rsp->PersistentFileId),
- le64_to_cpu(rsp->VolatileFileId));
+ rsp->PersistentFileId,
+ rsp->VolatileFileId);
This conflicts with the statement "store them verbatim". Because the
rsp->{Persistent,Volatile}FileId fields are u64 (integer) types,
they are not being stored verbatim, they are being manipulated
by the CPU load/store instructions. Storing them into a u8[8]
array is more to the point.
Yes, makes sense.
If course, if the rsp structure is purely private to the code, then
the structure element type is similarly private. But a debugger, or
a future structure reference, may once again get it wrong
Are you rejecting the idea of using a byte array?
No. That would work, too. I was just trying to avoid changing a lot of
places and eventually making it harder to backport.
I'll go with the byte array then.
If you want to reduce a bit of code change, you could let the
compiler generate the loads and stores via memcpy, with (perhaps)
a struct { u8[8] } instead of the bare array.
Tom.
