Commit 9a03c3d398 ("thunderbolt: Fix a couple right shifting to zero
bugs") revealed an issue that was previously hidden because we never
actually compared received XDomain message sequence numbers properly.
The idea with these sequence numbers is that the responding host uses
the same sequence number that was in the request packet which we can
then check at the requesting host.
However, testing against macOS it looks like it does not follow this but
instead uses some other logic. Windows driver on the other hand handles
it the same way than Linux.
In order to be able to talk to macOS again, fix this so that we drop the
whole sequence number check. This effectively works exactly the same
than it worked before the aforementioned commit. This also follows the
logic the original P2P networking code used.
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The problematic code looks like this:
res_seq = res_hdr->xd_hdr.length_sn & TB_XDOMAIN_SN_MASK;
res_seq >>= TB_XDOMAIN_SN_SHIFT;
TB_XDOMAIN_SN_SHIFT is 27, and right shifting a u8 27 bits is always
going to result in zero. The fix is to declare these variables as u32.
Fixes: d1ff70241a ("thunderbolt: Add support for XDomain discovery protocol")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The 0day kbuild robot reports following crash:
BUG: unable to handle kernel NULL pointer dereference at 00000004
IP: tb_property_find+0xe/0x41
*pde = 00000000
Oops: 0000 [#1]
CPU: 0 PID: 1 Comm: swapper Not tainted 4.14.0-rc1-00741-ge69b6c0 #412
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1 04/01/2014
task: 89c80000 task.stack: 89c7c000
EIP: tb_property_find+0xe/0x41
EFLAGS: 00210246 CPU: 0
EAX: 00000000 EBX: 7a368f47 ECX: 00000044 EDX: 7a368f47
ESI: 8851d340 EDI: 7a368f47 EBP: 89c7df0c ESP: 89c7defc
DS: 007b ES: 007b FS: 0000 GS: 0000 SS: 0068
CR0: 80050033 CR2: 00000004 CR3: 027a2000 CR4: 00000690
Call Trace:
tb_register_property_dir+0x49/0xb9
? cdc_mbim_driver_init+0x1b/0x1b
tbnet_init+0x77/0x9f
? cdc_mbim_driver_init+0x1b/0x1b
do_one_initcall+0x7e/0x145
? parse_args+0x10c/0x1b3
? kernel_init_freeable+0xbe/0x159
kernel_init_freeable+0xd1/0x159
? rest_init+0x110/0x110
kernel_init+0xd/0xd0
ret_from_fork+0x19/0x30
The reason is that both Thunderbolt bus and thunderbolt-net are build
into the kernel image, and the latter is linked first because
drivers/net comes before drivers/thunderbolt. Since both use
module_init() thunderbolt-net ends up calling Thunderbolt bus functions
too early triggering the above crash.
Fix this by moving Thunderbolt bus initialization to happen earlier to
make sure all the data structures are ready when Thunderbolt service
drivers are initialized. To be on the safe side also add a check for
properly initialized xdomain_property_dir to tb_register_property_dir().
Reported-by: kernel test robot <fengguang.wu@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When two hosts are connected over a Thunderbolt cable, there is a
protocol they can use to communicate capabilities supported by the host.
The discovery protocol uses automatically configured control channel
(ring 0) and is build on top of request/response transactions using
special XDomain primitives provided by the Thunderbolt base protocol.
The capabilities consists of a root directory block of basic properties
used for identification of the host, and then there can be zero or more
directories each describing a Thunderbolt service and its capabilities.
Once both sides have discovered what is supported the two hosts can
setup high-speed DMA paths and transfer data to the other side using
whatever protocol was agreed based on the properties. The software
protocol used to communicate which DMA paths to enable is service
specific.
This patch adds support for the XDomain discovery protocol to the
Thunderbolt bus. We model each remote host connection as a Linux XDomain
device. For each Thunderbolt service found supported on the XDomain
device, we create Linux Thunderbolt service device which Thunderbolt
service drivers can then bind to based on the protocol identification
information retrieved from the property directory describing the
service.
This code is based on the work done by Amir Levy and Michael Jamet.
Signed-off-by: Michael Jamet <michael.jamet@intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Mika Westerberg