AI Trajectory

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "KMSANReasoning": "",
  "NeedsKMSAN": false,
  "Reasoning": "The patch modifies the Thunderbolt networking driver (thunderbolt-net). This driver requires a Thunderbolt controller and XDomain connections to function. Since there is no software emulation for Thunderbolt controllers in standard QEMU (unlike USB with vhci or Wi-Fi with mac80211_hwsim), the driver cannot be probed and the modified code paths are impossible to reach in virtualized environments like GCE or QEMU.",
  "WorthFuzzing": false
}

null

{
  "PatchDiff": "commit 89bb1b75701d5fac3814fc907dff2569e8c20a51\nAuthor: syz-cluster \u003ctriage@syzkaller.com\u003e\nDate:   Tue Aug 11 13:34:41 2026 +0000\n\n    syz-cluster: applied patch under review\n\ndiff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c\nindex 98893732bc6e4..2a1728621887a 100644\n--- a/drivers/net/thunderbolt/main.c\n+++ b/drivers/net/thunderbolt/main.c\n@@ -626,6 +626,14 @@ static int tbnet_alloc_tx_buffers(struct tbnet *net)\n \treturn 0;\n }\n \n+static void tbnet_connect_failed(struct tbnet *net)\n+{\n+\t/* Leave login_received set: only the peer can make it true again. */\n+\tmutex_lock(\u0026net-\u003econnection_lock);\n+\tnet-\u003elogin_sent = false;\n+\tmutex_unlock(\u0026net-\u003econnection_lock);\n+}\n+\n static void tbnet_connected_work(struct work_struct *work)\n {\n \tstruct tbnet *net = container_of(work, typeof(*net), connected_work);\n@@ -647,6 +655,9 @@ static void tbnet_connected_work(struct work_struct *work)\n \tret = tb_xdomain_alloc_in_hopid(net-\u003exd, net-\u003eremote_transmit_path);\n \tif (ret != net-\u003eremote_transmit_path) {\n \t\tnetdev_err(net-\u003edev, \"failed to allocate Rx HopID\\n\");\n+\t\tif (ret \u003e= 0)\n+\t\t\ttb_xdomain_release_in_hopid(net-\u003exd, ret);\n+\t\ttbnet_connect_failed(net);\n \t\treturn;\n \t}\n \n@@ -691,6 +702,7 @@ static void tbnet_connected_work(struct work_struct *work)\n \ttb_ring_stop(net-\u003erx_ring.ring);\n \ttb_ring_stop(net-\u003etx_ring.ring);\n \ttb_xdomain_release_in_hopid(net-\u003exd, net-\u003eremote_transmit_path);\n+\ttbnet_connect_failed(net);\n }\n \n static void tbnet_login_work(struct work_struct *work)\n"
}

best-expensive

null

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch modifies the Thunderbolt networking driver (thunderbolt-net). This driver requires a Thunderbolt controller and XDomain connections to function. Since there is no software emulation for Thunderbolt controllers in standard QEMU (unlike USB with vhci or Wi-Fi with mac80211_hwsim), the driver cannot be probed and the modified code paths are impossible to reach in virtualized environments like GCE or QEMU.",
  "WorthFuzzing": false
}

You are an expert Linux kernel maintainer.
Your job is to review a provided patch series and determine
if it makes functional changes to the kernel that should be fuzzed.

IMPORTANT: The changes have ALREADY been applied and committed as the HEAD commit in
your workspace. Do NOT rely on your internal knowledge of the kernel. You must actively
use your code access tools to examine the actual source code and confirm any assumptions.

Return WorthFuzzing=false if the patch only contains:
- Modifications to Documentation/, Kconfig files, or code comments.
- Purely decorative changes, such as logging (e.g., pr_err, printk) or tracepoints.
- Changes to numeric constants or macros that do not functionally alter execution flow.
- Code paths that are impossible to reach in virtualized environments like GCE or QEMU,
  even when utilizing software-emulated hardware (e.g., usb gadget, mac80211_hwsim).
- Code in vendor-specific PCIe switch, SmartNIC, or GPU drivers (e.g., mlxsw, pds_core, qed,
  ionic, amdgpu) that require physical PCIe hardware cards not emulated in standard QEMU.
- Driver .remove, .shutdown, or pci_unregister_driver teardown callbacks (e.g., igb_remove)
  that are executed only during PCI hot-unplug or sysfs driver unbind operations.

If it modifies reachable core kernel logic, drivers, or architectures, use your code search
tools to verify the code can be executed, then return WorthFuzzing=true.

When returning WorthFuzzing=true, you MUST ALSO:
1. Extract any specific kernel functions that should be heavily fuzzed into FocusSymbols.
   Avoid listing generic hot-path functions to prevent skewed test distributions.
   Prefer non-static, non-inlined API entrypoint functions over internal static helper functions
   (which are inlined by the compiler and do not have distinct symbol addresses).
2. Identify any specific CONFIG_ options required to properly test this new/modified feature.
   Go and look into the Kconfig files and check for ifdefs around the code, do not make assumptions.
   Also check "depends on" lines in Kconfig to include any non-standard parent subsystem configs
   needed for Kbuild to compile the code statically into vmlinux. List them in the EnableConfigs
   output array, and DO NOT add a 'CONFIG_' prefix (e.g., return "NET_IPV4" instead of "CONFIG_NET_IPV4").
Prefer calling several tools at the same time to save round-trips.


Use set-results tool to provide results of the analysis.
It must be called exactly once before the final reply.
Ignore results of this tool.

For your convenience, here is the diff of the changes:
commit 89bb1b75701d5fac3814fc907dff2569e8c20a51
Author: syz-cluster <triage@syzkaller.com>
Date:   Tue Aug 11 13:34:41 2026 +0000

    syz-cluster: applied patch under review

diff --git a/drivers/net/thunderbolt/main.c b/drivers/net/thunderbolt/main.c
index 98893732bc6e4..2a1728621887a 100644
--- a/drivers/net/thunderbolt/main.c
+++ b/drivers/net/thunderbolt/main.c
@@ -626,6 +626,14 @@ static int tbnet_alloc_tx_buffers(struct tbnet *net)
 	return 0;
 }
 
+static void tbnet_connect_failed(struct tbnet *net)
+{
+	/* Leave login_received set: only the peer can make it true again. */
+	mutex_lock(&net->connection_lock);
+	net->login_sent = false;
+	mutex_unlock(&net->connection_lock);
+}
+
 static void tbnet_connected_work(struct work_struct *work)
 {
 	struct tbnet *net = container_of(work, typeof(*net), connected_work);
@@ -647,6 +655,9 @@ static void tbnet_connected_work(struct work_struct *work)
 	ret = tb_xdomain_alloc_in_hopid(net->xd, net->remote_transmit_path);
 	if (ret != net->remote_transmit_path) {
 		netdev_err(net->dev, "failed to allocate Rx HopID\n");
+		if (ret >= 0)
+			tb_xdomain_release_in_hopid(net->xd, ret);
+		tbnet_connect_failed(net);
 		return;
 	}
 
@@ -691,6 +702,7 @@ static void tbnet_connected_work(struct work_struct *work)
 	tb_ring_stop(net->rx_ring.ring);
 	tb_ring_stop(net->tx_ring.ring);
 	tb_xdomain_release_in_hopid(net->xd, net->remote_transmit_path);
+	tbnet_connect_failed(net);
 }
 
 static void tbnet_login_work(struct work_struct *work)

gemini-3.1-pro-preview

null

null

							input: 2314
							output: 28
							thoughts: 171
						

**Analyzing the Thunderbolt Networking Patch**

Okay, so I'm looking at this patch for `drivers/net/thunderbolt/main.c`. It seems they've added a `tbnet_connect_failed` function and are calling it within `tbnet_connected_work` when something goes wrong. Plus, there's this `tb_xdomain_release_in_hopid` call and a check before calling `tbnet_connect_failed`. That's standard error handling, nothing groundbreaking yet.

But wait, Thunderbolt networking... now my brain's going. Can we fuzz this in QEMU? Thunderbolt networking, that's not something you can just do without specific hardware, right? Or at least proper emulation. I know it's a critical area, but generally, Thunderbolt networking is highly hardware-dependent.

So, QEMU... does standard QEMU even *have* Thunderbolt emulation? I don't recall seeing any offhand. It's often a pretty specialized area. Need to confirm whether there's any software-based emulation available for Thunderbolt. Let's do a quick `grep` search for "thunderbolt" in the QEMU source or any relevant documentation to see if anything pops up. Need to establish a base layer before even thinking about potential fuzzing strategies.

{
  "Expression": "thunderbolt",
  "PathPrefix": "drivers/net/thunderbolt"
}

{
  "Output": "drivers/net/thunderbolt/Kconfig=2=config USB4_NET\n--\ndrivers/net/thunderbolt/Kconfig-11-\t  To compile this driver a module, choose M here. The module will be\ndrivers/net/thunderbolt/Kconfig:12:\t  called thunderbolt_net.\n--\ndrivers/net/thunderbolt/Makefile-1-# SPDX-License-Identifier: GPL-2.0\ndrivers/net/thunderbolt/Makefile:2:obj-$(CONFIG_USB4_NET) := thunderbolt_net.o\ndrivers/net/thunderbolt/Makefile:3:thunderbolt_net-objs := main.o trace.o\ndrivers/net/thunderbolt/Makefile-4-\n--\ndrivers/net/thunderbolt/main.c-20-#include \u003clinux/sizes.h\u003e\ndrivers/net/thunderbolt/main.c:21:#include \u003clinux/thunderbolt.h\u003e\ndrivers/net/thunderbolt/main.c-22-#include \u003clinux/uuid.h\u003e\n--\ndrivers/net/thunderbolt/main.c-43-#define TBNET_MAX_PAYLOAD_SIZE\t\\\ndrivers/net/thunderbolt/main.c:44:\t(TBNET_FRAME_SIZE - sizeof(struct thunderbolt_ip_frame_header))\ndrivers/net/thunderbolt/main.c-45-/* Rx packets need to hold space for skb_shared_info */\n--\ndrivers/net/thunderbolt/main.c-53-/**\ndrivers/net/thunderbolt/main.c:54: * struct thunderbolt_ip_frame_header - Header for each Thunderbolt frame\ndrivers/net/thunderbolt/main.c-55- * @frame_size: size of the data with the frame\n--\ndrivers/net/thunderbolt/main.c-63- */\ndrivers/net/thunderbolt/main.c:64:struct thunderbolt_ip_frame_header {\ndrivers/net/thunderbolt/main.c-65-\t__le32 frame_size;\n--\ndrivers/net/thunderbolt/main.c-70-\ndrivers/net/thunderbolt/main.c:71:enum thunderbolt_ip_frame_pdf {\ndrivers/net/thunderbolt/main.c-72-\tTBIP_PDF_FRAME_START = 1,\n--\ndrivers/net/thunderbolt/main.c-75-\ndrivers/net/thunderbolt/main.c:76:enum thunderbolt_ip_type {\ndrivers/net/thunderbolt/main.c-77-\tTBIP_LOGIN,\n--\ndrivers/net/thunderbolt/main.c-82-\ndrivers/net/thunderbolt/main.c:83:struct thunderbolt_ip_header {\ndrivers/net/thunderbolt/main.c-84-\tu32 route_hi;\n--\ndrivers/net/thunderbolt/main.c-97-\ndrivers/net/thunderbolt/main.c:98:struct thunderbolt_ip_login {\ndrivers/net/thunderbolt/main.c:99:\tstruct thunderbolt_ip_header hdr;\ndrivers/net/thunderbolt/main.c-100-\tu32 proto_version;\n--\ndrivers/net/thunderbolt/main.c-106-\ndrivers/net/thunderbolt/main.c:107:struct thunderbolt_ip_login_response {\ndrivers/net/thunderbolt/main.c:108:\tstruct thunderbolt_ip_header hdr;\ndrivers/net/thunderbolt/main.c-109-\tu32 status;\n--\ndrivers/net/thunderbolt/main.c-114-\ndrivers/net/thunderbolt/main.c:115:struct thunderbolt_ip_logout {\ndrivers/net/thunderbolt/main.c:116:\tstruct thunderbolt_ip_header hdr;\ndrivers/net/thunderbolt/main.c-117-};\ndrivers/net/thunderbolt/main.c-118-\ndrivers/net/thunderbolt/main.c:119:struct thunderbolt_ip_status {\ndrivers/net/thunderbolt/main.c:120:\tstruct thunderbolt_ip_header hdr;\ndrivers/net/thunderbolt/main.c-121-\tu32 status;\n--\ndrivers/net/thunderbolt/main.c=182=struct tbnet {\n--\ndrivers/net/thunderbolt/main.c-199-\tstruct work_struct disconnect_work;\ndrivers/net/thunderbolt/main.c:200:\tstruct thunderbolt_ip_frame_header rx_hdr;\ndrivers/net/thunderbolt/main.c-201-\tstruct tbnet_ring rx_ring;\n--\ndrivers/net/thunderbolt/main.c=220=MODULE_PARM_DESC(e2e, \"USB4NET full end-to-end flow control (default: true)\");\ndrivers/net/thunderbolt/main.c-221-\ndrivers/net/thunderbolt/main.c:222:static void tbnet_fill_header(struct thunderbolt_ip_header *hdr, u64 route,\ndrivers/net/thunderbolt/main.c-223-\tu8 sequence, const uuid_t *initiator_uuid, const uuid_t *target_uuid,\ndrivers/net/thunderbolt/main.c:224:\tenum thunderbolt_ip_type type, size_t size, u32 command_id)\ndrivers/net/thunderbolt/main.c-225-{\n--\ndrivers/net/thunderbolt/main.c=242=static int tbnet_login_response(struct tbnet *net, u64 route, u8 sequence,\n--\ndrivers/net/thunderbolt/main.c-244-{\ndrivers/net/thunderbolt/main.c:245:\tstruct thunderbolt_ip_login_response reply;\ndrivers/net/thunderbolt/main.c-246-\tstruct tb_xdomain *xd = net-\u003exd;\n--\ndrivers/net/thunderbolt/main.c=259=static int tbnet_login_request(struct tbnet *net, u8 sequence)\ndrivers/net/thunderbolt/main.c-260-{\ndrivers/net/thunderbolt/main.c:261:\tstruct thunderbolt_ip_login_response reply;\ndrivers/net/thunderbolt/main.c:262:\tstruct thunderbolt_ip_login request;\ndrivers/net/thunderbolt/main.c-263-\tstruct tb_xdomain *xd = net-\u003exd;\n--\ndrivers/net/thunderbolt/main.c=279=static int tbnet_logout_response(struct tbnet *net, u64 route, u8 sequence,\n--\ndrivers/net/thunderbolt/main.c-281-{\ndrivers/net/thunderbolt/main.c:282:\tstruct thunderbolt_ip_status reply;\ndrivers/net/thunderbolt/main.c-283-\tstruct tb_xdomain *xd = net-\u003exd;\n--\ndrivers/net/thunderbolt/main.c=293=static int tbnet_logout_request(struct tbnet *net)\ndrivers/net/thunderbolt/main.c-294-{\ndrivers/net/thunderbolt/main.c:295:\tstruct thunderbolt_ip_logout request;\ndrivers/net/thunderbolt/main.c:296:\tstruct thunderbolt_ip_status reply;\ndrivers/net/thunderbolt/main.c-297-\tstruct tb_xdomain *xd = net-\u003exd;\n--\ndrivers/net/thunderbolt/main.c=425=static int tbnet_handle_packet(const void *buf, size_t size, void *data)\ndrivers/net/thunderbolt/main.c-426-{\ndrivers/net/thunderbolt/main.c:427:\tconst struct thunderbolt_ip_login *pkg = buf;\ndrivers/net/thunderbolt/main.c-428-\tstruct tbnet *net = data;\n--\ndrivers/net/thunderbolt/main.c-434-\t/* Make sure the packet is for us */\ndrivers/net/thunderbolt/main.c:435:\tif (size \u003c sizeof(struct thunderbolt_ip_header))\ndrivers/net/thunderbolt/main.c-436-\t\treturn 0;\n--\ndrivers/net/thunderbolt/main.c=750=static bool tbnet_check_frame(struct tbnet *net, const struct tbnet_frame *tf,\ndrivers/net/thunderbolt/main.c:751:\t\t\t      const struct thunderbolt_ip_frame_header *hdr)\ndrivers/net/thunderbolt/main.c-752-{\n--\ndrivers/net/thunderbolt/main.c=825=static int tbnet_poll(struct napi_struct *napi, int budget)\n--\ndrivers/net/thunderbolt/main.c-832-\twhile (rx_packets \u003c budget) {\ndrivers/net/thunderbolt/main.c:833:\t\tconst struct thunderbolt_ip_frame_header *hdr;\ndrivers/net/thunderbolt/main.c-834-\t\tunsigned int hdr_size = sizeof(*hdr);\n--\ndrivers/net/thunderbolt/main.c=1015=static bool tbnet_xmit_csum_and_map(struct tbnet *net, struct sk_buff *skb,\n--\ndrivers/net/thunderbolt/main.c-1017-{\ndrivers/net/thunderbolt/main.c:1018:\tstruct thunderbolt_ip_frame_header *hdr = page_address(frames[0]-\u003epage);\ndrivers/net/thunderbolt/main.c-1019-\tstruct device *dma_dev = tb_ring_dma_device(net-\u003etx_ring.ring);\n--\ndrivers/net/thunderbolt/main.c=1130=static netdev_tx_t tbnet_start_xmit(struct sk_buff *skb,\n--\ndrivers/net/thunderbolt/main.c-1135-\tu16 frame_id = atomic_read(\u0026net-\u003eframe_id);\ndrivers/net/thunderbolt/main.c:1136:\tstruct thunderbolt_ip_frame_header *hdr;\ndrivers/net/thunderbolt/main.c-1137-\tunsigned int len = skb_headlen(skb);\n--\ndrivers/net/thunderbolt/main.c=1365=static int tbnet_probe(struct tb_service *svc, const struct tb_service_id *id)\n--\ndrivers/net/thunderbolt/main.c-1390-\ndrivers/net/thunderbolt/main.c:1391:\tstrcpy(dev-\u003ename, \"thunderbolt%d\");\ndrivers/net/thunderbolt/main.c-1392-\tdev-\u003enetdev_ops = \u0026tbnet_netdev_ops;\n--\ndrivers/net/thunderbolt/main.c-1410-\tdev-\u003efeatures = dev-\u003ehw_features | NETIF_F_HIGHDMA;\ndrivers/net/thunderbolt/main.c:1411:\tdev-\u003ehard_header_len += sizeof(struct thunderbolt_ip_frame_header);\ndrivers/net/thunderbolt/main.c-1412-\n--\ndrivers/net/thunderbolt/main.c=1489=static struct tb_service_driver tbnet_driver = {\n--\ndrivers/net/thunderbolt/main.c-1491-\t\t.owner = THIS_MODULE,\ndrivers/net/thunderbolt/main.c:1492:\t\t.name = \"thunderbolt-net\",\ndrivers/net/thunderbolt/main.c-1493-\t\t.pm = pm_sleep_ptr(\u0026tbnet_pm_ops),\n--\ndrivers/net/thunderbolt/trace.h-9-#undef TRACE_SYSTEM\ndrivers/net/thunderbolt/trace.h:10:#define TRACE_SYSTEM thunderbolt_net\ndrivers/net/thunderbolt/trace.h-11-\n"
}

gemini-3.1-pro-preview

null

null

							input: 5719
							output: 22
							thoughts: 130
						

**Investigating Thunderbolt Fuzzing with Syzkaller**

Okay, so the driver in question is `thunderbolt-net`, specifically the USB4_NET interface. My immediate thought is, can I fuzz this thing using syzkaller? That's the obvious first question. Let's see if syzkaller even has any descriptions related to thunderbolt. Ah, right, the instructions! They're reminding me that I can't just blindly search the syzkaller code base (`sys/*`) for "thunderbolt" because I need to be careful with how syzkaller handles its internal pseudo-syscalls. Things that start with "syz_" are off-limits for a straight search here. I need to use those other tools they mentioned - `read-syz-spec` and `syz-grepper` - if I'm looking for *real* kernel-level syzlang descriptions. Okay, that makes sense. So, back to the initial question: are there *any* syzkaller descriptions for thunderbolt at all? I need to check.

{
  "Expression": "thunderbolt",
  "PathPrefix": ""
}

{
  "Output": "\nFull output is too long, showing 500 out of 1224 lines.\nUse more precise expression if possible.\n\nDocumentation/ABI/testing/configfs-thunderbolt_stream:1:What:\t\t/sys/kernel/config/thunderbolt/stream/\u003cxdomain\u003e.\u003cservice\u003e\nDocumentation/ABI/testing/configfs-thunderbolt_stream-2-Date:\t\tSep 2026\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream=5=Description:\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream-20-\nDocumentation/ABI/testing/configfs-thunderbolt_stream:21:What:\t\t/sys/kernel/config/thunderbolt/stream/\u003cxdomain\u003e.\u003cservice\u003e/$name\nDocumentation/ABI/testing/configfs-thunderbolt_stream-22-Date:\t\tSep 2026\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream=25=Description:\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream-29-\nDocumentation/ABI/testing/configfs-thunderbolt_stream:30:What:\t\t/sys/kernel/config/thunderbolt/stream/\u003cxdomain\u003e.\u003cservice\u003e/$name/index\nDocumentation/ABI/testing/configfs-thunderbolt_stream-31-Date:\t\tSep 2026\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream=34=Description:\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream-38-\nDocumentation/ABI/testing/configfs-thunderbolt_stream:39:What:\t\t/sys/kernel/config/thunderbolt/stream/\u003cxdomain\u003e.\u003cservice\u003e/$name/in_hopid\nDocumentation/ABI/testing/configfs-thunderbolt_stream-40-Date:\t\tSep 2026\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream=43=Description:\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream-57-\nDocumentation/ABI/testing/configfs-thunderbolt_stream:58:What:\t\t/sys/kernel/config/thunderbolt/stream/\u003cxdomain\u003e.\u003cservice\u003e/$name/out_hopid\nDocumentation/ABI/testing/configfs-thunderbolt_stream-59-Date:\t\tSep 2026\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream=62=Description:\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream-68-\nDocumentation/ABI/testing/configfs-thunderbolt_stream:69:What:\t\t/sys/kernel/config/thunderbolt/stream/\u003cxdomain\u003e.\u003cservice\u003e/$name/ring_size\nDocumentation/ABI/testing/configfs-thunderbolt_stream-70-Date:\t\tSep 2026\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream=73=Description:\n--\nDocumentation/ABI/testing/configfs-thunderbolt_stream-76-\nDocumentation/ABI/testing/configfs-thunderbolt_stream:77:What:\t\t/sys/kernel/config/thunderbolt/stream/\u003cxdomain\u003e.\u003cservice\u003e/$name/throttling\nDocumentation/ABI/testing/configfs-thunderbolt_stream-78-Date:\t\tSep 2026\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:1:What:\t\t/sys/bus/thunderbolt/devices/.../domainX/boot_acl\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-2-Date:\t\tJun 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=5=Description:\tHolds a comma separated list of device unique_ids that\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-23-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:24:What:\t\t/sys/bus/thunderbolt/devices/.../domainX/deauthorization\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-25-Date:\t\tMay 2021\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=28=Description:\tThis attribute tells whether the system supports\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-32-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:33:What:\t\t/sys/bus/thunderbolt/devices/.../domainX/iommu_dma_protection\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-34-Date:\t\tMar 2019\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=37=Description:\tThis attribute tells whether the system uses IOMMU\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-41-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:42:What:\t\t/sys/bus/thunderbolt/devices/.../domainX/security\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-43-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=46=Description:\tThis attribute holds current Thunderbolt security level\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-63-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:64:What:\t\t/sys/bus/thunderbolt/devices/.../authorized\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-65-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=68=Description:\tThis attribute is used to authorize Thunderbolt devices\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-97-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:98:What:\t\t/sys/bus/thunderbolt/devices/.../boot\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-99-Date:\t\tJun 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=102=Description:\tThis attribute contains 1 if Thunderbolt device was already\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-104-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:105:What:\t\t/sys/bus/thunderbolt/devices/.../generation\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-106-Date:\t\tJan 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=109=Description:\tThis attribute contains the generation of the Thunderbolt\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-112-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:113:What:\t\t/sys/bus/thunderbolt/devices/.../key\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-114-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=117=Description:\tWhen a devices supports Thunderbolt secure connect it will\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-122-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:123:What:\t\t/sys/bus/thunderbolt/devices/.../device\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-124-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=127=Description:\tThis attribute contains id of this device extracted from\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-129-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:130:What:\t\t/sys/bus/thunderbolt/devices/.../device_name\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-131-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=134=Description:\tThis attribute contains name of this device extracted from\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-136-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:137:What:\t\t/sys/bus/thunderbolt/devices/.../maxhopid\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-138-Date:\t\tJul 2021\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=141=Description:\tOnly set for XDomains. The maximum HopID the other host\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-143-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:144:What:\t\t/sys/bus/thunderbolt/devices/.../rx_speed\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-145-Date:\t\tJan 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=148=Description:\tThis attribute reports the device RX speed per lane.\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-150-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:151:What:\t\t/sys/bus/thunderbolt/devices/.../rx_lanes\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-152-Date:\t\tJan 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=155=Description:\tThis attribute reports number of RX lanes the device is\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-157-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:158:What:\t\t/sys/bus/thunderbolt/devices/.../tx_speed\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-159-Date:\t\tJan 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=162=Description:\tThis attribute reports the TX speed per lane.\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-164-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:165:What:\t\t/sys/bus/thunderbolt/devices/.../tx_lanes\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-166-Date:\t\tJan 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=169=Description:\tThis attribute reports number of TX lanes the device is\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-171-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:172:What:\t\t/sys/bus/thunderbolt/devices/.../vendor\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-173-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=176=Description:\tThis attribute contains vendor id of this device extracted\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-178-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:179:What:\t\t/sys/bus/thunderbolt/devices/.../vendor_name\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-180-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=183=Description:\tThis attribute contains vendor name of this device extracted\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-185-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:186:What:\t\t/sys/bus/thunderbolt/devices/.../unique_id\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-187-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=190=Description:\tThis attribute contains unique_id string of this device.\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-194-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:195:What:\t\t/sys/bus/thunderbolt/devices/.../nvm_version\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-196-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=199=Description:\tIf the device has upgradeable firmware the version\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-203-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:204:What:\t\t/sys/bus/thunderbolt/devices/.../nvm_authenticate\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-205-Date:\t\tSep 2017\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=208=Description:\tWhen new NVM image is written to the non-active NVM\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-231-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:232:What:\t\t/sys/bus/thunderbolt/devices/.../nvm_authenticate_on_disconnect\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-233-Date:\t\tOct 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=236=Description:\tFor supported devices, automatically authenticate the new Thunderbolt\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-245-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:246:What:\t\t/sys/bus/thunderbolt/devices/\u003cxdomain\u003e.\u003cservice\u003e/key\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-247-Date:\t\tJan 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=250=Description:\tThis contains name of the property directory the XDomain\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-260-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:261:What:\t\t/sys/bus/thunderbolt/devices/\u003cxdomain\u003e.\u003cservice\u003e/modalias\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-262-Date:\t\tJan 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=265=Description:\tStores the same MODALIAS value emitted by uevent for\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-267-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:268:What:\t\t/sys/bus/thunderbolt/devices/\u003cxdomain\u003e.\u003cservice\u003e/prtcid\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-269-Date:\t\tJan 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=272=Description:\tThis contains XDomain protocol identifier the XDomain\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-274-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:275:What:\t\t/sys/bus/thunderbolt/devices/\u003cxdomain\u003e.\u003cservice\u003e/prtcvers\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-276-Date:\t\tJan 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=279=Description:\tThis contains XDomain protocol version the XDomain\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-281-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:282:What:\t\t/sys/bus/thunderbolt/devices/\u003cxdomain\u003e.\u003cservice\u003e/prtcrevs\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-283-Date:\t\tJan 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=286=Description:\tThis contains XDomain software version the XDomain\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-288-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:289:What:\t\t/sys/bus/thunderbolt/devices/\u003cxdomain\u003e.\u003cservice\u003e/prtcstns\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-290-Date:\t\tJan 2018\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=293=Description:\tThis contains XDomain service specific settings as\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-295-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:296:What:\t\t/sys/bus/thunderbolt/devices/usb4_portX/connector\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-297-Date:\t\tApril 2022\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=299=Description:\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-305-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:306:What:\t\t/sys/bus/thunderbolt/devices/usb4_portX/link\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-307-Date:\t\tSep 2021\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=310=Description:\tReturns the current link mode. Possible values are\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-312-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:313:What:\t\t/sys/bus/thunderbolt/devices/usb4_portX/offline\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-314-Date:\t\tSep 2021\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=317=Description:\tWriting 1 to this attribute puts the USB4 port into\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-327-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:328:What:\t\t/sys/bus/thunderbolt/devices/usb4_portX/rescan\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-329-Date:\t\tSep 2021\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=332=Description:\tWhen the USB4 port is in offline mode writing 1 to this\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-338-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:339:What:\t\t/sys/bus/thunderbolt/devices/\u003cdevice\u003e:\u003cport\u003e.\u003cindex\u003e/device\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-340-Date:\t\tOct 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=343=Description:\tRetimer device identifier read from the hardware.\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-344-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:345:What:\t\t/sys/bus/thunderbolt/devices/\u003cdevice\u003e:\u003cport\u003e.\u003cindex\u003e/nvm_authenticate\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-346-Date:\t\tOct 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=349=Description:\tWhen new NVM image is written to the non-active NVM\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-359-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:360:What:\t\t/sys/bus/thunderbolt/devices/\u003cdevice\u003e:\u003cport\u003e.\u003cindex\u003e/nvm_version\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-361-Date:\t\tOct 2020\n--\nDocumentation/ABI/testing/sysfs-bus-thunderbolt=364=Description:\tHolds retimer NVM version number. Format: %x.%x, major.minor.\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-365-\nDocumentation/ABI/testing/sysfs-bus-thunderbolt:366:What:\t\t/sys/bus/thunderbolt/devices/\u003cdevice\u003e:\u003cport\u003e.\u003cindex\u003e/vendor\nDocumentation/ABI/testing/sysfs-bus-thunderbolt-367-Date:\t\tOct 2020\n--\nDocumentation/admin-guide/index.rst=140=How to configure your hardware within your Linux system.\n--\nDocumentation/admin-guide/index.rst-164-   thermal/index\nDocumentation/admin-guide/index.rst:165:   thunderbolt\nDocumentation/admin-guide/index.rst-166-   vga-softcursor\n--\nDocumentation/admin-guide/thunderbolt.rst=30=More details about the sysfs interface for Thunderbolt devices can be\nDocumentation/admin-guide/thunderbolt.rst:31:found in Documentation/ABI/testing/sysfs-bus-thunderbolt.\nDocumentation/admin-guide/thunderbolt.rst-32-\n--\nDocumentation/admin-guide/thunderbolt.rst=34=manual work can add following line to\n--\nDocumentation/admin-guide/thunderbolt.rst-36-\nDocumentation/admin-guide/thunderbolt.rst:37:  ACTION==\"add\", SUBSYSTEM==\"thunderbolt\", ATTR{authorized}==\"0\", ATTR{authorized}=\"1\"\nDocumentation/admin-guide/thunderbolt.rst-38-\n--\nDocumentation/admin-guide/thunderbolt.rst=53=The security levels are as follows:\n--\nDocumentation/admin-guide/thunderbolt.rst-62-    Based on the device identification information available through\nDocumentation/admin-guide/thunderbolt.rst:63:    ``/sys/bus/thunderbolt/devices``, the user then can make the decision.\nDocumentation/admin-guide/thunderbolt.rst-64-    In BIOS settings this is typically called *Unique ID*.\n--\nDocumentation/admin-guide/thunderbolt.rst=87=The current security level can be read from\nDocumentation/admin-guide/thunderbolt.rst:88:``/sys/bus/thunderbolt/devices/domainX/security`` where ``domainX`` is\nDocumentation/admin-guide/thunderbolt.rst-89-the Thunderbolt domain the host controller manages. There is typically\n--\nDocumentation/admin-guide/thunderbolt.rst=96=Each Thunderbolt device plugged in will appear in sysfs under\nDocumentation/admin-guide/thunderbolt.rst:97:``/sys/bus/thunderbolt/devices``. The device directory carries\nDocumentation/admin-guide/thunderbolt.rst-98-information that can be used to identify the particular device,\n--\nDocumentation/admin-guide/thunderbolt.rst=103=When a device is plugged in it will appear in sysfs as follows::\nDocumentation/admin-guide/thunderbolt.rst-104-\nDocumentation/admin-guide/thunderbolt.rst:105:  /sys/bus/thunderbolt/devices/0-1/authorized\t- 0\nDocumentation/admin-guide/thunderbolt.rst:106:  /sys/bus/thunderbolt/devices/0-1/device\t- 0x8004\nDocumentation/admin-guide/thunderbolt.rst:107:  /sys/bus/thunderbolt/devices/0-1/device_name\t- Thunderbolt to FireWire Adapter\nDocumentation/admin-guide/thunderbolt.rst:108:  /sys/bus/thunderbolt/devices/0-1/vendor\t- 0x1\nDocumentation/admin-guide/thunderbolt.rst:109:  /sys/bus/thunderbolt/devices/0-1/vendor_name\t- Apple, Inc.\nDocumentation/admin-guide/thunderbolt.rst:110:  /sys/bus/thunderbolt/devices/0-1/unique_id\t- e0376f00-0300-0100-ffff-ffffffffffff\nDocumentation/admin-guide/thunderbolt.rst-111-\n--\nDocumentation/admin-guide/thunderbolt.rst=113=created yet. The user can authorize the device by simply entering::\nDocumentation/admin-guide/thunderbolt.rst-114-\nDocumentation/admin-guide/thunderbolt.rst:115:  # echo 1 \u003e /sys/bus/thunderbolt/devices/0-1/authorized\nDocumentation/admin-guide/thunderbolt.rst-116-\n--\nDocumentation/admin-guide/thunderbolt.rst=122=future connects::\nDocumentation/admin-guide/thunderbolt.rst-123-\nDocumentation/admin-guide/thunderbolt.rst:124:  /sys/bus/thunderbolt/devices/0-3/authorized\t- 0\nDocumentation/admin-guide/thunderbolt.rst:125:  /sys/bus/thunderbolt/devices/0-3/device\t- 0x305\nDocumentation/admin-guide/thunderbolt.rst:126:  /sys/bus/thunderbolt/devices/0-3/device_name\t- AKiTiO Thunder3 PCIe Box\nDocumentation/admin-guide/thunderbolt.rst:127:  /sys/bus/thunderbolt/devices/0-3/key\t\t-\nDocumentation/admin-guide/thunderbolt.rst:128:  /sys/bus/thunderbolt/devices/0-3/vendor\t- 0x41\nDocumentation/admin-guide/thunderbolt.rst:129:  /sys/bus/thunderbolt/devices/0-3/vendor_name\t- inXtron\nDocumentation/admin-guide/thunderbolt.rst:130:  /sys/bus/thunderbolt/devices/0-3/unique_id\t- dc010000-0000-8508-a22d-32ca6421cb16\nDocumentation/admin-guide/thunderbolt.rst-131-\n--\nDocumentation/admin-guide/thunderbolt.rst=139=plugged a key needs to be created and sent to the device::\n--\nDocumentation/admin-guide/thunderbolt.rst-141-  # key=$(openssl rand -hex 32)\nDocumentation/admin-guide/thunderbolt.rst:142:  # echo $key \u003e /sys/bus/thunderbolt/devices/0-3/key\nDocumentation/admin-guide/thunderbolt.rst:143:  # echo 1 \u003e /sys/bus/thunderbolt/devices/0-3/authorized\nDocumentation/admin-guide/thunderbolt.rst-144-\n--\nDocumentation/admin-guide/thunderbolt.rst=149=device using the same key::\nDocumentation/admin-guide/thunderbolt.rst-150-\nDocumentation/admin-guide/thunderbolt.rst:151:  # echo $key \u003e /sys/bus/thunderbolt/devices/0-3/key\nDocumentation/admin-guide/thunderbolt.rst:152:  # echo 2 \u003e /sys/bus/thunderbolt/devices/0-3/authorized\nDocumentation/admin-guide/thunderbolt.rst-153-\n--\nDocumentation/admin-guide/thunderbolt.rst=186=systems can be identified by reading ``1`` from\nDocumentation/admin-guide/thunderbolt.rst:187:``/sys/bus/thunderbolt/devices/domainX/iommu_dma_protection`` attribute.\nDocumentation/admin-guide/thunderbolt.rst-188-\n--\nDocumentation/admin-guide/thunderbolt.rst=195=following ``udev`` rule::\nDocumentation/admin-guide/thunderbolt.rst-196-\nDocumentation/admin-guide/thunderbolt.rst:197:  ACTION==\"add\", SUBSYSTEM==\"thunderbolt\", ATTRS{iommu_dma_protection}==\"1\", ATTR{authorized}==\"0\", ATTR{authorized}=\"1\"\nDocumentation/admin-guide/thunderbolt.rst-198-\n--\nDocumentation/admin-guide/thunderbolt.rst=250=of the host or device. Example on how to update Intel NUC6i7KYK\n--\nDocumentation/admin-guide/thunderbolt.rst-252-\nDocumentation/admin-guide/thunderbolt.rst:253:  # dd if=KYK_TBT_FW_0018.bin of=/sys/bus/thunderbolt/devices/0-0/nvm_non_active0/nvmem\nDocumentation/admin-guide/thunderbolt.rst-254-\n--\nDocumentation/admin-guide/thunderbolt.rst=256=upgrade process as follows::\nDocumentation/admin-guide/thunderbolt.rst-257-\nDocumentation/admin-guide/thunderbolt.rst:258:  # echo 1 \u003e /sys/bus/thunderbolt/devices/0-0/nvm_authenticate\nDocumentation/admin-guide/thunderbolt.rst-259-\n--\nDocumentation/admin-guide/thunderbolt.rst=264=commands::\nDocumentation/admin-guide/thunderbolt.rst-265-\nDocumentation/admin-guide/thunderbolt.rst:266:  # cat /sys/bus/thunderbolt/devices/0-0/nvm_authenticate\nDocumentation/admin-guide/thunderbolt.rst-267-  0x0\nDocumentation/admin-guide/thunderbolt.rst:268:  # cat /sys/bus/thunderbolt/devices/0-0/nvm_version\nDocumentation/admin-guide/thunderbolt.rst-269-  18.0\n--\nDocumentation/admin-guide/thunderbolt.rst=285=is to first put the USB4 port into offline mode::\nDocumentation/admin-guide/thunderbolt.rst-286-\nDocumentation/admin-guide/thunderbolt.rst:287:  # echo 1 \u003e /sys/bus/thunderbolt/devices/0-0/usb4_port1/offline\nDocumentation/admin-guide/thunderbolt.rst-288-\n--\nDocumentation/admin-guide/thunderbolt.rst=291=for the retimers::\nDocumentation/admin-guide/thunderbolt.rst-292-\nDocumentation/admin-guide/thunderbolt.rst:293:  # echo 1 \u003e /sys/bus/thunderbolt/devices/0-0/usb4_port1/rescan\nDocumentation/admin-guide/thunderbolt.rst-294-\n--\nDocumentation/admin-guide/thunderbolt.rst=298=mode) so after writing ``1`` to ``nvm_authenticate`` one should wait for\n--\nDocumentation/admin-guide/thunderbolt.rst-300-\nDocumentation/admin-guide/thunderbolt.rst:301:  # echo 1 \u003e /sys/bus/thunderbolt/devices/0-0/usb4_port1/rescan\nDocumentation/admin-guide/thunderbolt.rst-302-\n--\nDocumentation/admin-guide/thunderbolt.rst=304=functional state again::\nDocumentation/admin-guide/thunderbolt.rst-305-\nDocumentation/admin-guide/thunderbolt.rst:306:  # echo 0 \u003e /sys/bus/thunderbolt/devices/0-0/usb4_port1/offline\nDocumentation/admin-guide/thunderbolt.rst-307-\n--\nDocumentation/admin-guide/thunderbolt.rst=321=The driver sends ``KOBJ_CHANGE`` events to userspace when there is a\nDocumentation/admin-guide/thunderbolt.rst:322:tunneling change in the ``thunderbolt_domain``. The notification carries\nDocumentation/admin-guide/thunderbolt.rst-323-following environment variables::\n--\nDocumentation/admin-guide/thunderbolt.rst=361=do is to connect a Thunderbolt cable between the two hosts; the\nDocumentation/admin-guide/thunderbolt.rst:362:``thunderbolt-net`` driver is loaded automatically. If the other host is\nDocumentation/admin-guide/thunderbolt.rst:363:also Linux you should load ``thunderbolt-net`` manually on one host (it\nDocumentation/admin-guide/thunderbolt.rst-364-does not matter which one)::\nDocumentation/admin-guide/thunderbolt.rst-365-\nDocumentation/admin-guide/thunderbolt.rst:366:  # modprobe thunderbolt-net\nDocumentation/admin-guide/thunderbolt.rst-367-\n--\nDocumentation/admin-guide/thunderbolt.rst=371=The driver will create one virtual ethernet interface per Thunderbolt\nDocumentation/admin-guide/thunderbolt.rst:372:port which are named like ``thunderbolt0`` and so on. From this point\nDocumentation/admin-guide/thunderbolt.rst-373-you can either use standard userspace tools like ``ip`` to\n--\nDocumentation/admin-guide/thunderbolt.rst=379=streaming data directly over a cable as well (aka. USB4STREAM). This is\nDocumentation/admin-guide/thunderbolt.rst:380:possible through ``thunderbolt-stream`` driver.\nDocumentation/admin-guide/thunderbolt.rst-381-\nDocumentation/admin-guide/thunderbolt.rst:382:Similarly to ``thunderbolt-net`` you load the driver first on one end::\nDocumentation/admin-guide/thunderbolt.rst-383-\nDocumentation/admin-guide/thunderbolt.rst:384:  host1 # modprobe thunderbolt-stream\nDocumentation/admin-guide/thunderbolt.rst-385-\nDocumentation/admin-guide/thunderbolt.rst=386=Then you configure it via ``ConfigFS``::\nDocumentation/admin-guide/thunderbolt.rst-387-\nDocumentation/admin-guide/thunderbolt.rst:388:  host1 # cd /sys/kernel/config/thunderbolt/stream\nDocumentation/admin-guide/thunderbolt.rst-389-  host1 # mkdir -p 0-1.0/data\n--\nDocumentation/admin-guide/thunderbolt.rst=397=you automatically::\nDocumentation/admin-guide/thunderbolt.rst-398-\nDocumentation/admin-guide/thunderbolt.rst:399:  host2 # cd /sys/kernel/config/thunderbolt/stream\nDocumentation/admin-guide/thunderbolt.rst-400-  host2 # mkdir -p 0-3.0/data\n--\nDocumentation/admin-guide/thunderbolt.rst=413=Once you are done with the stream you can remove them::\nDocumentation/admin-guide/thunderbolt.rst-414-\nDocumentation/admin-guide/thunderbolt.rst:415:  host2 # cd /sys/kernel/config/thunderbolt/stream\nDocumentation/admin-guide/thunderbolt.rst-416-  host2 # rmdir -p 0-1.0/data\nDocumentation/admin-guide/thunderbolt.rst:417:  host1 # cd /sys/kernel/config/thunderbolt/stream\nDocumentation/admin-guide/thunderbolt.rst-418-  host1 # rmdir -p 0-3.0/data\n--\nDocumentation/admin-guide/thunderbolt.rst=423=It is possible to have more than one stream and you can have both stream\nDocumentation/admin-guide/thunderbolt.rst:424:and ``thunderbolt-net`` in use simultaneously. For example we can create\nDocumentation/admin-guide/thunderbolt.rst-425-two streams with name ``control`` and ``data`` like this::\nDocumentation/admin-guide/thunderbolt.rst-426-\nDocumentation/admin-guide/thunderbolt.rst:427:  host1 # cd /sys/kernel/config/thunderbolt/stream\nDocumentation/admin-guide/thunderbolt.rst-428-  host1 # mkdir 0-1.0\n--\nDocumentation/admin-guide/thunderbolt.rst=442=a sysfs attribute called \"force_power\", see\nDocumentation/admin-guide/thunderbolt.rst:443:Documentation/ABI/testing/sysfs-platform-intel-wmi-thunderbolt for details.\nDocumentation/admin-guide/thunderbolt.rst-444-\n--\nDocumentation/security/snp-tdx-threat-model.rst=17=the kernel through various networking or limited HW-specific exposed\nDocumentation/security/snp-tdx-threat-model.rst:18:interfaces (USB, thunderbolt). The goal of this document is to explain\nDocumentation/security/snp-tdx-threat-model.rst-19-additional attack vectors that arise in the confidential computing space\n--\nDocumentation/translations/zh_CN/admin-guide/index.rst=75=Todolist:\n--\nDocumentation/translations/zh_CN/admin-guide/index.rst-120-*   svga\nDocumentation/translations/zh_CN/admin-guide/index.rst:121:*   thunderbolt\nDocumentation/translations/zh_CN/admin-guide/index.rst-122-*   ufs\n--\nDocumentation/translations/zh_TW/admin-guide/index.rst=77=Todolist:\n--\nDocumentation/translations/zh_TW/admin-guide/index.rst-123-*   svga\nDocumentation/translations/zh_TW/admin-guide/index.rst:124:*   thunderbolt\nDocumentation/translations/zh_TW/admin-guide/index.rst-125-*   ufs\n--\nDocumentation/wmi/driver-development-guide.rst=116=the number of instances can be retrieved using wmidev_instance_count().\nDocumentation/wmi/driver-development-guide.rst-117-\nDocumentation/wmi/driver-development-guide.rst:118:Take a look at drivers/platform/x86/intel/wmi/thunderbolt.c for an example WMI method driver.\nDocumentation/wmi/driver-development-guide.rst-119-\n--\nMAINTAINERS=13485=S:\tMaintained\nMAINTAINERS:13486:F:\tdrivers/platform/x86/intel/wmi/thunderbolt.c\nMAINTAINERS-13487-\n--\nMAINTAINERS=26906=S:\tMaintained\nMAINTAINERS:26907:F:\tdrivers/thunderbolt/dma_test.c\nMAINTAINERS-26908-\n--\nMAINTAINERS=26914=S:\tMaintained\nMAINTAINERS:26915:T:\tgit git://git.kernel.org/pub/scm/linux/kernel/git/westeri/thunderbolt.git\nMAINTAINERS:26916:F:\tDocumentation/admin-guide/thunderbolt.rst\nMAINTAINERS:26917:F:\tdrivers/thunderbolt/\nMAINTAINERS:26918:F:\tinclude/linux/thunderbolt.h\nMAINTAINERS-26919-\n--\nMAINTAINERS=26924=S:\tMaintained\nMAINTAINERS:26925:F:\tdrivers/net/thunderbolt/\nMAINTAINERS-26926-\n--\ndrivers/Kconfig=214=source \"drivers/ras/Kconfig\"\ndrivers/Kconfig-215-\ndrivers/Kconfig:216:source \"drivers/thunderbolt/Kconfig\"\ndrivers/Kconfig-217-\n--\ndrivers/Makefile=175=obj-$(CONFIG_RAS)\t\t+= ras/\ndrivers/Makefile:176:obj-$(CONFIG_USB4)\t\t+= thunderbolt/\ndrivers/Makefile-177-obj-$(CONFIG_CORESIGHT)\t\t+= hwtracing/coresight/\n--\ndrivers/gpu/drm/nouveau/nouveau_vga.c=87=nouveau_vga_init(struct nouveau_drm *drm)\n--\ndrivers/gpu/drm/nouveau/nouveau_vga.c-100-\t/* don't register Thunderbolt eGPU with vga_switcheroo */\ndrivers/gpu/drm/nouveau/nouveau_vga.c:101:\tif (pci_is_thunderbolt_attached(pdev))\ndrivers/gpu/drm/nouveau/nouveau_vga.c-102-\t\treturn;\n--\ndrivers/gpu/drm/nouveau/nouveau_vga.c=111=nouveau_vga_fini(struct nouveau_drm *drm)\n--\ndrivers/gpu/drm/nouveau/nouveau_vga.c-123-\ndrivers/gpu/drm/nouveau/nouveau_vga.c:124:\tif (pci_is_thunderbolt_attached(pdev))\ndrivers/gpu/drm/nouveau/nouveau_vga.c-125-\t\treturn;\n--\ndrivers/gpu/drm/radeon/radeon_device.c=1279=int radeon_device_init(struct radeon_device *rdev,\n--\ndrivers/gpu/drm/radeon/radeon_device.c-1430-\t\truntime = true;\ndrivers/gpu/drm/radeon/radeon_device.c:1431:\tif (!pci_is_thunderbolt_attached(rdev-\u003epdev))\ndrivers/gpu/drm/radeon/radeon_device.c-1432-\t\tvga_switcheroo_register_client(rdev-\u003epdev,\n--\ndrivers/gpu/drm/radeon/radeon_device.c=1513=void radeon_device_fini(struct radeon_device *rdev)\n--\ndrivers/gpu/drm/radeon/radeon_device.c-1520-\tradeon_fini(rdev);\ndrivers/gpu/drm/radeon/radeon_device.c:1521:\tif (!pci_is_thunderbolt_attached(rdev-\u003epdev))\ndrivers/gpu/drm/radeon/radeon_device.c-1522-\t\tvga_switcheroo_unregister_client(rdev-\u003epdev);\n--\ndrivers/gpu/drm/radeon/radeon_kms.c=103=int radeon_driver_load_kms(struct drm_device *dev, unsigned long flags)\n--\ndrivers/gpu/drm/radeon/radeon_kms.c-133-\t    ((flags \u0026 RADEON_IS_IGP) == 0) \u0026\u0026\ndrivers/gpu/drm/radeon/radeon_kms.c:134:\t    !pci_is_thunderbolt_attached(pdev))\ndrivers/gpu/drm/radeon/radeon_kms.c-135-\t\tflags |= RADEON_IS_PX;\n--\ndrivers/net/Kconfig=594=config FUJITSU_ES\n--\ndrivers/net/Kconfig-600-\ndrivers/net/Kconfig:601:source \"drivers/net/thunderbolt/Kconfig\"\ndrivers/net/Kconfig-602-source \"drivers/net/hyperv/Kconfig\"\n--\ndrivers/net/Makefile=85=obj-$(CONFIG_FUJITSU_ES) += fjes/\ndrivers/net/Makefile:86:obj-$(CONFIG_USB4_NET) += thunderbolt/\ndrivers/net/Makefile-87-obj-$(CONFIG_NETDEVSIM) += netdevsim/\n\n"
}

gemini-3.1-pro-preview

null

null

							input: 16497
							output: 33
							thoughts: 183
						

**Thunderbolt Networking Code Exploration**

Okay, so I'm looking at `drivers/net/thunderbolt/Kconfig` and I see this `config USB4_NET` option, which is interesting. The core functionality seems to reside in `drivers/thunderbolt/`, as I'd expect. Now, my mind drifts to fuzzing – are there any existing syzkaller pseudo-syscalls defined for thunderbolt? No, probably not, I shouldn't even bother searching for `syz_`. But hang on, the patch I'm interested in is in `drivers/net/thunderbolt/main.c`.

The real question becomes: Can I even reach this code within a QEMU environment? Thunderbolt networking is known to involve Thunderbolt domains and XDomain connections. The tricky part is, can QEMU emulate the Thunderbolt hardware itself? I need to figure out if there's any available software emulation in the kernel for this, something similar to how `mac80211_hwsim` or `vhci` work for other subsystems. Time to grep for `thunderbolt` within `drivers/thunderbolt/`. Maybe there's a dedicated software testing driver that would make this process much easier.

{
  "Expression": "kunit|test|mock|sim",
  "PathPrefix": "drivers/thunderbolt/"
}

{
  "Output": "\nFull output is too long, showing 500 out of 2361 lines.\nUse more precise expression if possible.\n\ndrivers/thunderbolt/Kconfig=49=config USB4_KUNIT_TEST\ndrivers/thunderbolt/Kconfig:50:\tbool \"KUnit tests\" if !KUNIT_ALL_TESTS\ndrivers/thunderbolt/Kconfig-51-\tdepends on USB4 \u0026\u0026 KUNIT=y\n--\ndrivers/thunderbolt/Kconfig=54=config USB4_DMA_TEST\ndrivers/thunderbolt/Kconfig:55:\ttristate \"DMA traffic test driver\"\ndrivers/thunderbolt/Kconfig-56-\tdepends on DEBUG_FS\n--\ndrivers/thunderbolt/Kconfig-59-\t  connection. Loopback connection can be done by either special\ndrivers/thunderbolt/Kconfig:60:\t  dongle that has TX/RX lines crossed, or by simply connecting a\ndrivers/thunderbolt/Kconfig-61-\t  cable back to the host. Only enable this if you know what you\n--\ndrivers/thunderbolt/Kconfig-64-\t  To compile this driver a module, choose M here. The module will be\ndrivers/thunderbolt/Kconfig:65:\t  called thunderbolt_dma_test.\ndrivers/thunderbolt/Kconfig-66-\n--\ndrivers/thunderbolt/Makefile=10=thunderbolt-$(CONFIG_USB4_CONFIGFS) += configfs.o\ndrivers/thunderbolt/Makefile:11:thunderbolt-${CONFIG_USB4_KUNIT_TEST} += test.o\ndrivers/thunderbolt/Makefile:12:CFLAGS_test.o += $(DISABLE_STRUCTLEAK_PLUGIN)\ndrivers/thunderbolt/Makefile-13-\ndrivers/thunderbolt/Makefile:14:thunderbolt_dma_test-${CONFIG_USB4_DMA_TEST} += dma_test.o\ndrivers/thunderbolt/Makefile:15:obj-$(CONFIG_USB4_DMA_TEST) += thunderbolt_dma_test.o\ndrivers/thunderbolt/Makefile-16-\n--\ndrivers/thunderbolt/ctl.c=133=static int tb_cfg_request_enqueue(struct tb_ctl *ctl,\n--\ndrivers/thunderbolt/ctl.c-135-{\ndrivers/thunderbolt/ctl.c:136:\tWARN_ON(test_bit(TB_CFG_REQUEST_ACTIVE, \u0026req-\u003eflags));\ndrivers/thunderbolt/ctl.c-137-\tWARN_ON(req-\u003ectl);\n--\ndrivers/thunderbolt/ctl.c=151=static void tb_cfg_request_dequeue(struct tb_cfg_request *req)\n--\ndrivers/thunderbolt/ctl.c-155-\tmutex_lock(\u0026ctl-\u003erequest_queue_lock);\ndrivers/thunderbolt/ctl.c:156:\tif (!test_bit(TB_CFG_REQUEST_ACTIVE, \u0026req-\u003eflags)) {\ndrivers/thunderbolt/ctl.c-157-\t\tmutex_unlock(\u0026ctl-\u003erequest_queue_lock);\n--\ndrivers/thunderbolt/ctl.c-162-\tclear_bit(TB_CFG_REQUEST_ACTIVE, \u0026req-\u003eflags);\ndrivers/thunderbolt/ctl.c:163:\tif (test_bit(TB_CFG_REQUEST_CANCELED, \u0026req-\u003eflags))\ndrivers/thunderbolt/ctl.c-164-\t\twake_up(\u0026tb_cfg_request_cancel_queue);\n--\ndrivers/thunderbolt/ctl.c=168=static bool tb_cfg_request_is_active(struct tb_cfg_request *req)\ndrivers/thunderbolt/ctl.c-169-{\ndrivers/thunderbolt/ctl.c:170:\treturn test_bit(TB_CFG_REQUEST_ACTIVE, \u0026req-\u003eflags);\ndrivers/thunderbolt/ctl.c-171-}\n--\ndrivers/thunderbolt/ctl.c=524=static void tb_cfg_request_work(struct work_struct *work)\n--\ndrivers/thunderbolt/ctl.c-527-\ndrivers/thunderbolt/ctl.c:528:\tif (!test_bit(TB_CFG_REQUEST_CANCELED, \u0026req-\u003eflags))\ndrivers/thunderbolt/ctl.c-529-\t\treq-\u003ecallback(req-\u003ecallback_data);\n--\ndrivers/thunderbolt/debugfs.c=414=static ssize_t retimer_sb_regs_write(struct file *file,\n--\ndrivers/thunderbolt/debugfs.c-483- * @time: %true if time margining is used instead of voltage\ndrivers/thunderbolt/debugfs.c:484: * @right_high: %false if left/low margin test is performed, %true if\ndrivers/thunderbolt/debugfs.c-485- *\t\tright/high\n--\ndrivers/thunderbolt/debugfs.c=681=static int margining_caps_show(struct seq_file *s, void *not_used)\n--\ndrivers/thunderbolt/debugfs.c-705-\ndrivers/thunderbolt/debugfs.c:706:\tseq_printf(s, \"# all lanes simultaneously: %s\\n\",\ndrivers/thunderbolt/debugfs.c-707-\t\t  str_yes_no(all_lanes(margining)));\n--\ndrivers/thunderbolt/debugfs.c=1153=static int margining_run_sw(struct tb_margining *margining,\n--\ndrivers/thunderbolt/debugfs.c-1183-\ndrivers/thunderbolt/debugfs.c:1184:\t\t/* Any errors stop the test */\ndrivers/thunderbolt/debugfs.c-1185-\t\tif (errors)\n--\ndrivers/thunderbolt/debugfs.c=1473=DEBUGFS_ATTR_RW(margining_results);\ndrivers/thunderbolt/debugfs.c-1474-\ndrivers/thunderbolt/debugfs.c:1475:static ssize_t margining_test_write(struct file *file,\ndrivers/thunderbolt/debugfs.c-1476-\t\t\t\t    const char __user *user_buf,\n--\ndrivers/thunderbolt/debugfs.c-1509-\ndrivers/thunderbolt/debugfs.c:1510:static int margining_test_show(struct seq_file *s, void *not_used)\ndrivers/thunderbolt/debugfs.c-1511-{\n--\ndrivers/thunderbolt/debugfs.c-1529-}\ndrivers/thunderbolt/debugfs.c:1530:DEBUGFS_ATTR_RW(margining_test);\ndrivers/thunderbolt/debugfs.c-1531-\n--\ndrivers/thunderbolt/debugfs.c=1650=static struct tb_margining *margining_alloc(struct tb_port *port,\n--\ndrivers/thunderbolt/debugfs.c-1738-\t\t\t    \u0026margining_results_fops);\ndrivers/thunderbolt/debugfs.c:1739:\tdebugfs_create_file(\"test\", 0600, dir, margining, \u0026margining_test_fops);\ndrivers/thunderbolt/debugfs.c-1740-\tif (independent_voltage_margins(margining) == USB4_MARGIN_CAP_VOLTAGE_INDP_GEN_2_3_HL ||\n--\ndrivers/thunderbolt/dma_test.c-2-/*\ndrivers/thunderbolt/dma_test.c:3: * DMA traffic test driver\ndrivers/thunderbolt/dma_test.c-4- *\n--\ndrivers/thunderbolt/dma_test.c-21-\ndrivers/thunderbolt/dma_test.c:22:enum dma_test_frame_pdf {\ndrivers/thunderbolt/dma_test.c-23-\tDMA_TEST_PDF_FRAME_START = 1,\n--\ndrivers/thunderbolt/dma_test.c-26-\ndrivers/thunderbolt/dma_test.c:27:struct dma_test_frame {\ndrivers/thunderbolt/dma_test.c:28:\tstruct dma_test *dma_test;\ndrivers/thunderbolt/dma_test.c-29-\tvoid *data;\n--\ndrivers/thunderbolt/dma_test.c-32-\ndrivers/thunderbolt/dma_test.c:33:enum dma_test_test_error {\ndrivers/thunderbolt/dma_test.c-34-\tDMA_TEST_NO_ERROR,\n--\ndrivers/thunderbolt/dma_test.c-44-\ndrivers/thunderbolt/dma_test.c:45:static const char * const dma_test_error_names[] = {\ndrivers/thunderbolt/dma_test.c-46-\t[DMA_TEST_NO_ERROR] = \"no errors\",\n--\ndrivers/thunderbolt/dma_test.c-56-\ndrivers/thunderbolt/dma_test.c:57:enum dma_test_result {\ndrivers/thunderbolt/dma_test.c-58-\tDMA_TEST_NOT_RUN,\n--\ndrivers/thunderbolt/dma_test.c-62-\ndrivers/thunderbolt/dma_test.c:63:static const char * const dma_test_result_names[] = {\ndrivers/thunderbolt/dma_test.c-64-\t[DMA_TEST_NOT_RUN] = \"not run\",\n--\ndrivers/thunderbolt/dma_test.c-69-/**\ndrivers/thunderbolt/dma_test.c:70: * struct dma_test - DMA test device driver private data\ndrivers/thunderbolt/dma_test.c-71- * @svc: XDomain service the driver is bound to\n--\ndrivers/thunderbolt/dma_test.c-82- * @link_width: Expected link width (Gb/s), %0 to use whatever is negotiated\ndrivers/thunderbolt/dma_test.c:83: * @crc_errors: Number of CRC errors during the test run\ndrivers/thunderbolt/dma_test.c:84: * @buffer_overflow_errors: Number of buffer overflow errors during the test\ndrivers/thunderbolt/dma_test.c-85- *\t\t\t    run\n--\ndrivers/thunderbolt/dma_test.c-90- */\ndrivers/thunderbolt/dma_test.c:91:struct dma_test {\ndrivers/thunderbolt/dma_test.c-92-\tconst struct tb_service *svc;\n--\ndrivers/thunderbolt/dma_test.c-105-\tunsigned int buffer_overflow_errors;\ndrivers/thunderbolt/dma_test.c:106:\tenum dma_test_result result;\ndrivers/thunderbolt/dma_test.c:107:\tenum dma_test_test_error error_code;\ndrivers/thunderbolt/dma_test.c-108-\tstruct completion complete;\n--\ndrivers/thunderbolt/dma_test.c-111-\ndrivers/thunderbolt/dma_test.c:112:/* DMA test property directory UUID: 3188cd10-6523-4a5a-a682-fdca07a248d8 */\ndrivers/thunderbolt/dma_test.c:113:static const uuid_t dma_test_dir_uuid =\ndrivers/thunderbolt/dma_test.c-114-\tUUID_INIT(0x3188cd10, 0x6523, 0x4a5a,\n--\ndrivers/thunderbolt/dma_test.c-116-\ndrivers/thunderbolt/dma_test.c:117:static struct tb_property_dir *dma_test_dir;\ndrivers/thunderbolt/dma_test.c:118:static void *dma_test_pattern;\ndrivers/thunderbolt/dma_test.c-119-\ndrivers/thunderbolt/dma_test.c:120:static void dma_test_free_rings(struct dma_test *dt)\ndrivers/thunderbolt/dma_test.c-121-{\n--\ndrivers/thunderbolt/dma_test.c-133-\ndrivers/thunderbolt/dma_test.c:134:static int dma_test_start_rings(struct dma_test *dt)\ndrivers/thunderbolt/dma_test.c-135-{\n--\ndrivers/thunderbolt/dma_test.c-161-\t\tif (ret \u003c 0) {\ndrivers/thunderbolt/dma_test.c:162:\t\t\tdma_test_free_rings(dt);\ndrivers/thunderbolt/dma_test.c-163-\t\t\treturn ret;\n--\ndrivers/thunderbolt/dma_test.c-179-\t\tif (!ring) {\ndrivers/thunderbolt/dma_test.c:180:\t\t\tdma_test_free_rings(dt);\ndrivers/thunderbolt/dma_test.c-181-\t\t\treturn -ENOMEM;\n--\ndrivers/thunderbolt/dma_test.c-189-\t\tif (ret \u003c 0) {\ndrivers/thunderbolt/dma_test.c:190:\t\t\tdma_test_free_rings(dt);\ndrivers/thunderbolt/dma_test.c-191-\t\t\treturn ret;\n--\ndrivers/thunderbolt/dma_test.c-201-\tif (ret) {\ndrivers/thunderbolt/dma_test.c:202:\t\tdma_test_free_rings(dt);\ndrivers/thunderbolt/dma_test.c-203-\t\treturn ret;\n--\ndrivers/thunderbolt/dma_test.c-213-\ndrivers/thunderbolt/dma_test.c:214:static void dma_test_stop_rings(struct dma_test *dt)\ndrivers/thunderbolt/dma_test.c-215-{\n--\ndrivers/thunderbolt/dma_test.c-229-\ndrivers/thunderbolt/dma_test.c:230:\tdma_test_free_rings(dt);\ndrivers/thunderbolt/dma_test.c-231-}\ndrivers/thunderbolt/dma_test.c-232-\ndrivers/thunderbolt/dma_test.c:233:static void dma_test_rx_callback(struct tb_ring *ring, struct ring_frame *frame,\ndrivers/thunderbolt/dma_test.c-234-\t\t\t\t bool canceled)\ndrivers/thunderbolt/dma_test.c-235-{\ndrivers/thunderbolt/dma_test.c:236:\tstruct dma_test_frame *tf = container_of(frame, typeof(*tf), frame);\ndrivers/thunderbolt/dma_test.c:237:\tstruct dma_test *dt = tf-\u003edma_test;\ndrivers/thunderbolt/dma_test.c-238-\tstruct device *dma_dev = tb_ring_dma_device(dt-\u003erx_ring);\n--\ndrivers/thunderbolt/dma_test.c-263-\ndrivers/thunderbolt/dma_test.c:264:static int dma_test_submit_rx(struct dma_test *dt, size_t npackets)\ndrivers/thunderbolt/dma_test.c-265-{\n--\ndrivers/thunderbolt/dma_test.c-269-\tfor (i = 0; i \u003c npackets; i++) {\ndrivers/thunderbolt/dma_test.c:270:\t\tstruct dma_test_frame *tf;\ndrivers/thunderbolt/dma_test.c-271-\t\tdma_addr_t dma_addr;\n--\ndrivers/thunderbolt/dma_test.c-291-\t\ttf-\u003eframe.buffer_phy = dma_addr;\ndrivers/thunderbolt/dma_test.c:292:\t\ttf-\u003eframe.callback = dma_test_rx_callback;\ndrivers/thunderbolt/dma_test.c:293:\t\ttf-\u003edma_test = dt;\ndrivers/thunderbolt/dma_test.c-294-\t\tINIT_LIST_HEAD(\u0026tf-\u003eframe.list);\n--\ndrivers/thunderbolt/dma_test.c-301-\ndrivers/thunderbolt/dma_test.c:302:static void dma_test_tx_callback(struct tb_ring *ring, struct ring_frame *frame,\ndrivers/thunderbolt/dma_test.c-303-\t\t\t\t bool canceled)\ndrivers/thunderbolt/dma_test.c-304-{\ndrivers/thunderbolt/dma_test.c:305:\tstruct dma_test_frame *tf = container_of(frame, typeof(*tf), frame);\ndrivers/thunderbolt/dma_test.c:306:\tstruct dma_test *dt = tf-\u003edma_test;\ndrivers/thunderbolt/dma_test.c-307-\tstruct device *dma_dev = tb_ring_dma_device(dt-\u003etx_ring);\n--\ndrivers/thunderbolt/dma_test.c-314-\ndrivers/thunderbolt/dma_test.c:315:static int dma_test_submit_tx(struct dma_test *dt, size_t npackets)\ndrivers/thunderbolt/dma_test.c-316-{\n--\ndrivers/thunderbolt/dma_test.c-320-\tfor (i = 0; i \u003c npackets; i++) {\ndrivers/thunderbolt/dma_test.c:321:\t\tstruct dma_test_frame *tf;\ndrivers/thunderbolt/dma_test.c-322-\t\tdma_addr_t dma_addr;\n--\ndrivers/thunderbolt/dma_test.c-328-\t\ttf-\u003eframe.size = 0; /* means 4096 */\ndrivers/thunderbolt/dma_test.c:329:\t\ttf-\u003edma_test = dt;\ndrivers/thunderbolt/dma_test.c-330-\ndrivers/thunderbolt/dma_test.c:331:\t\ttf-\u003edata = kmemdup(dma_test_pattern, DMA_TEST_FRAME_SIZE, GFP_KERNEL);\ndrivers/thunderbolt/dma_test.c-332-\t\tif (!tf-\u003edata) {\n--\ndrivers/thunderbolt/dma_test.c-345-\t\ttf-\u003eframe.buffer_phy = dma_addr;\ndrivers/thunderbolt/dma_test.c:346:\t\ttf-\u003eframe.callback = dma_test_tx_callback;\ndrivers/thunderbolt/dma_test.c-347-\t\ttf-\u003eframe.sof = DMA_TEST_PDF_FRAME_START;\n--\ndrivers/thunderbolt/dma_test.c=362=static int __fops ## _show(void *data, u64 *val)\t\t\\\n--\ndrivers/thunderbolt/dma_test.c-364-\tstruct tb_service *svc = data;\t\t\t\t\\\ndrivers/thunderbolt/dma_test.c:365:\tstruct dma_test *dt = tb_service_get_drvdata(svc);\t\\\ndrivers/thunderbolt/dma_test.c-366-\tint ret;\t\t\t\t\t\t\\\n--\ndrivers/thunderbolt/dma_test.c=375=static int __fops ## _store(void *data, u64 val)\t\t\\\n--\ndrivers/thunderbolt/dma_test.c-377-\tstruct tb_service *svc = data;\t\t\t\t\\\ndrivers/thunderbolt/dma_test.c:378:\tstruct dma_test *dt = tb_service_get_drvdata(svc);\t\\\ndrivers/thunderbolt/dma_test.c-379-\tint ret;\t\t\t\t\t\t\\\n--\ndrivers/thunderbolt/dma_test.c=391=DEFINE_DEBUGFS_ATTRIBUTE(__fops ## _fops, __fops ## _show,\t\\\n--\ndrivers/thunderbolt/dma_test.c-393-\ndrivers/thunderbolt/dma_test.c:394:static void lanes_get(const struct dma_test *dt, u64 *val)\ndrivers/thunderbolt/dma_test.c-395-{\n--\ndrivers/thunderbolt/dma_test.c=399=static int lanes_validate(u64 val)\n--\ndrivers/thunderbolt/dma_test.c-403-\ndrivers/thunderbolt/dma_test.c:404:static void lanes_set(struct dma_test *dt, u64 val)\ndrivers/thunderbolt/dma_test.c-405-{\n--\ndrivers/thunderbolt/dma_test.c=408=DMA_TEST_DEBUGFS_ATTR(lanes, lanes_get, lanes_validate, lanes_set);\ndrivers/thunderbolt/dma_test.c-409-\ndrivers/thunderbolt/dma_test.c:410:static void speed_get(const struct dma_test *dt, u64 *val)\ndrivers/thunderbolt/dma_test.c-411-{\n--\ndrivers/thunderbolt/dma_test.c=415=static int speed_validate(u64 val)\n--\ndrivers/thunderbolt/dma_test.c-427-\ndrivers/thunderbolt/dma_test.c:428:static void speed_set(struct dma_test *dt, u64 val)\ndrivers/thunderbolt/dma_test.c-429-{\n--\ndrivers/thunderbolt/dma_test.c=432=DMA_TEST_DEBUGFS_ATTR(speed, speed_get, speed_validate, speed_set);\ndrivers/thunderbolt/dma_test.c-433-\ndrivers/thunderbolt/dma_test.c:434:static void packets_to_receive_get(const struct dma_test *dt, u64 *val)\ndrivers/thunderbolt/dma_test.c-435-{\n--\ndrivers/thunderbolt/dma_test.c=439=static int packets_to_receive_validate(u64 val)\n--\ndrivers/thunderbolt/dma_test.c-443-\ndrivers/thunderbolt/dma_test.c:444:static void packets_to_receive_set(struct dma_test *dt, u64 val)\ndrivers/thunderbolt/dma_test.c-445-{\n--\ndrivers/thunderbolt/dma_test.c=448=DMA_TEST_DEBUGFS_ATTR(packets_to_receive, packets_to_receive_get,\n--\ndrivers/thunderbolt/dma_test.c-450-\ndrivers/thunderbolt/dma_test.c:451:static void packets_to_send_get(const struct dma_test *dt, u64 *val)\ndrivers/thunderbolt/dma_test.c-452-{\n--\ndrivers/thunderbolt/dma_test.c=456=static int packets_to_send_validate(u64 val)\n--\ndrivers/thunderbolt/dma_test.c-460-\ndrivers/thunderbolt/dma_test.c:461:static void packets_to_send_set(struct dma_test *dt, u64 val)\ndrivers/thunderbolt/dma_test.c-462-{\n--\ndrivers/thunderbolt/dma_test.c=465=DMA_TEST_DEBUGFS_ATTR(packets_to_send, packets_to_send_get,\n--\ndrivers/thunderbolt/dma_test.c-467-\ndrivers/thunderbolt/dma_test.c:468:static int dma_test_set_bonding(struct dma_test *dt)\ndrivers/thunderbolt/dma_test.c-469-{\n--\ndrivers/thunderbolt/dma_test.c-480-\ndrivers/thunderbolt/dma_test.c:481:static bool dma_test_validate_config(struct dma_test *dt)\ndrivers/thunderbolt/dma_test.c-482-{\n--\ndrivers/thunderbolt/dma_test.c-490-\ndrivers/thunderbolt/dma_test.c:491:static void dma_test_check_errors(struct dma_test *dt, int ret)\ndrivers/thunderbolt/dma_test.c-492-{\n--\ndrivers/thunderbolt/dma_test.c-509-\ndrivers/thunderbolt/dma_test.c:510:static int test_store(void *data, u64 val)\ndrivers/thunderbolt/dma_test.c-511-{\ndrivers/thunderbolt/dma_test.c-512-\tstruct tb_service *svc = data;\ndrivers/thunderbolt/dma_test.c:513:\tstruct dma_test *dt = tb_service_get_drvdata(svc);\ndrivers/thunderbolt/dma_test.c-514-\tint ret;\n--\ndrivers/thunderbolt/dma_test.c-529-\ndrivers/thunderbolt/dma_test.c:530:\tdev_dbg(\u0026svc-\u003edev, \"DMA test starting\\n\");\ndrivers/thunderbolt/dma_test.c-531-\tif (dt-\u003elink_speed)\n--\ndrivers/thunderbolt/dma_test.c-537-\ndrivers/thunderbolt/dma_test.c:538:\tif (!dma_test_validate_config(dt)) {\ndrivers/thunderbolt/dma_test.c:539:\t\tdev_err(\u0026svc-\u003edev, \"invalid test configuration\\n\");\ndrivers/thunderbolt/dma_test.c-540-\t\tdt-\u003eerror_code = DMA_TEST_CONFIG_ERROR;\n--\ndrivers/thunderbolt/dma_test.c-543-\ndrivers/thunderbolt/dma_test.c:544:\tret = dma_test_set_bonding(dt);\ndrivers/thunderbolt/dma_test.c-545-\tif (ret) {\n--\ndrivers/thunderbolt/dma_test.c-550-\ndrivers/thunderbolt/dma_test.c:551:\tret = dma_test_start_rings(dt);\ndrivers/thunderbolt/dma_test.c-552-\tif (ret) {\n--\ndrivers/thunderbolt/dma_test.c-559-\t\treinit_completion(\u0026dt-\u003ecomplete);\ndrivers/thunderbolt/dma_test.c:560:\t\tret = dma_test_submit_rx(dt, dt-\u003epackets_to_receive);\ndrivers/thunderbolt/dma_test.c-561-\t\tif (ret) {\n--\ndrivers/thunderbolt/dma_test.c-568-\tif (dt-\u003epackets_to_send) {\ndrivers/thunderbolt/dma_test.c:569:\t\tret = dma_test_submit_tx(dt, dt-\u003epackets_to_send);\ndrivers/thunderbolt/dma_test.c-570-\t\tif (ret) {\n--\ndrivers/thunderbolt/dma_test.c-585-out_stop:\ndrivers/thunderbolt/dma_test.c:586:\tdma_test_stop_rings(dt);\ndrivers/thunderbolt/dma_test.c-587-out_unlock:\ndrivers/thunderbolt/dma_test.c:588:\tdma_test_check_errors(dt, ret);\ndrivers/thunderbolt/dma_test.c-589-\tmutex_unlock(\u0026dt-\u003elock);\ndrivers/thunderbolt/dma_test.c-590-\ndrivers/thunderbolt/dma_test.c:591:\tdev_dbg(\u0026svc-\u003edev, \"DMA test %s\\n\", dma_test_result_names[dt-\u003eresult]);\ndrivers/thunderbolt/dma_test.c-592-\treturn ret;\ndrivers/thunderbolt/dma_test.c-593-}\ndrivers/thunderbolt/dma_test.c:594:DEFINE_DEBUGFS_ATTRIBUTE(test_fops, NULL, test_store, \"%llu\\n\");\ndrivers/thunderbolt/dma_test.c-595-\ndrivers/thunderbolt/dma_test.c=596=static int status_show(struct seq_file *s, void *not_used)\n--\ndrivers/thunderbolt/dma_test.c-598-\tstruct tb_service *svc = s-\u003eprivate;\ndrivers/thunderbolt/dma_test.c:599:\tstruct dma_test *dt = tb_service_get_drvdata(svc);\ndrivers/thunderbolt/dma_test.c-600-\tint ret;\n--\ndrivers/thunderbolt/dma_test.c-605-\ndrivers/thunderbolt/dma_test.c:606:\tseq_printf(s, \"result: %s\\n\", dma_test_result_names[dt-\u003eresult]);\ndrivers/thunderbolt/dma_test.c-607-\tif (dt-\u003eresult == DMA_TEST_NOT_RUN)\n--\ndrivers/thunderbolt/dma_test.c-614-\t\t   dt-\u003ebuffer_overflow_errors);\ndrivers/thunderbolt/dma_test.c:615:\tseq_printf(s, \"error: %s\\n\", dma_test_error_names[dt-\u003eerror_code]);\ndrivers/thunderbolt/dma_test.c-616-\n--\ndrivers/thunderbolt/dma_test.c=621=DEFINE_SHOW_ATTRIBUTE(status);\ndrivers/thunderbolt/dma_test.c-622-\ndrivers/thunderbolt/dma_test.c:623:static void dma_test_debugfs_init(struct tb_service *svc)\ndrivers/thunderbolt/dma_test.c-624-{\n--\ndrivers/thunderbolt/dma_test.c-626-\ndrivers/thunderbolt/dma_test.c:627:\tdebugfs_dir = debugfs_create_dir(\"dma_test\", svc-\u003edebugfs_dir);\ndrivers/thunderbolt/dma_test.c-628-\n--\ndrivers/thunderbolt/dma_test.c-635-\tdebugfs_create_file(\"status\", 0400, debugfs_dir, svc, \u0026status_fops);\ndrivers/thunderbolt/dma_test.c:636:\tdebugfs_create_file(\"test\", 0200, debugfs_dir, svc, \u0026test_fops);\ndrivers/thunderbolt/dma_test.c-637-}\ndrivers/thunderbolt/dma_test.c-638-\ndrivers/thunderbolt/dma_test.c:639:static int dma_test_probe(struct tb_service *svc, const struct tb_service_id *id)\ndrivers/thunderbolt/dma_test.c-640-{\ndrivers/thunderbolt/dma_test.c-641-\tstruct tb_xdomain *xd = tb_service_parent(svc);\ndrivers/thunderbolt/dma_test.c:642:\tstruct dma_test *dt;\ndrivers/thunderbolt/dma_test.c-643-\n--\ndrivers/thunderbolt/dma_test.c-653-\ttb_service_set_drvdata(svc, dt);\ndrivers/thunderbolt/dma_test.c:654:\tdma_test_debugfs_init(svc);\ndrivers/thunderbolt/dma_test.c-655-\n--\ndrivers/thunderbolt/dma_test.c-658-\ndrivers/thunderbolt/dma_test.c:659:static void dma_test_remove(struct tb_service *svc)\ndrivers/thunderbolt/dma_test.c-660-{\ndrivers/thunderbolt/dma_test.c:661:\tstruct dma_test *dt = tb_service_get_drvdata(svc);\ndrivers/thunderbolt/dma_test.c-662-\ndrivers/thunderbolt/dma_test.c-663-\tmutex_lock(\u0026dt-\u003elock);\ndrivers/thunderbolt/dma_test.c:664:\tdebugfs_lookup_and_remove(\"dma_test\", svc-\u003edebugfs_dir);\ndrivers/thunderbolt/dma_test.c-665-\tmutex_unlock(\u0026dt-\u003elock);\n--\ndrivers/thunderbolt/dma_test.c-667-\ndrivers/thunderbolt/dma_test.c:668:static int __maybe_unused dma_test_suspend(struct device *dev)\ndrivers/thunderbolt/dma_test.c-669-{\n--\ndrivers/thunderbolt/dma_test.c-671-\t * No need to do anything special here. If userspace is writing\ndrivers/thunderbolt/dma_test.c:672:\t * to the test attribute when suspend started, it comes out from\ndrivers/thunderbolt/dma_test.c-673-\t * wait_for_completion_interruptible() with -ERESTARTSYS and the\ndrivers/thunderbolt/dma_test.c:674:\t * DMA test fails tearing down the rings. Once userspace is\ndrivers/thunderbolt/dma_test.c-675-\t * thawed the kernel restarts the write syscall effectively\ndrivers/thunderbolt/dma_test.c:676:\t * re-running the test.\ndrivers/thunderbolt/dma_test.c-677-\t */\n--\ndrivers/thunderbolt/dma_test.c-680-\ndrivers/thunderbolt/dma_test.c:681:static int __maybe_unused dma_test_resume(struct device *dev)\ndrivers/thunderbolt/dma_test.c-682-{\n--\ndrivers/thunderbolt/dma_test.c-685-\ndrivers/thunderbolt/dma_test.c:686:static const struct dev_pm_ops dma_test_pm_ops = {\ndrivers/thunderbolt/dma_test.c:687:\tSET_SYSTEM_SLEEP_PM_OPS(dma_test_suspend, dma_test_resume)\ndrivers/thunderbolt/dma_test.c-688-};\ndrivers/thunderbolt/dma_test.c-689-\ndrivers/thunderbolt/dma_test.c:690:static const struct tb_service_id dma_test_ids[] = {\ndrivers/thunderbolt/dma_test.c:691:\t{ TB_SERVICE(\"dma_test\", 1) },\ndrivers/thunderbolt/dma_test.c-692-\t{ },\ndrivers/thunderbolt/dma_test.c-693-};\ndrivers/thunderbolt/dma_test.c:694:MODULE_DEVICE_TABLE(tbsvc, dma_test_ids);\ndrivers/thunderbolt/dma_test.c-695-\ndrivers/thunderbolt/dma_test.c:696:static struct tb_service_driver dma_test_driver = {\ndrivers/thunderbolt/dma_test.c-697-\t.driver = {\ndrivers/thunderbolt/dma_test.c-698-\t\t.owner = THIS_MODULE,\ndrivers/thunderbolt/dma_test.c:699:\t\t.name = \"thunderbolt_dma_test\",\ndrivers/thunderbolt/dma_test.c:700:\t\t.pm = \u0026dma_test_pm_ops,\ndrivers/thunderbolt/dma_test.c-701-\t},\ndrivers/thunderbolt/dma_test.c:702:\t.probe = dma_test_probe,\ndrivers/thunderbolt/dma_test.c:703:\t.remove = dma_test_remove,\ndrivers/thunderbolt/dma_test.c:704:\t.id_table = dma_test_ids,\ndrivers/thunderbolt/dma_test.c-705-};\ndrivers/thunderbolt/dma_test.c-706-\ndrivers/thunderbolt/dma_test.c:707:static int __init dma_test_init(void)\ndrivers/thunderbolt/dma_test.c-708-{\n--\ndrivers/thunderbolt/dma_test.c-711-\ndrivers/thunderbolt/dma_test.c:712:\tdma_test_pattern = kmalloc(DMA_TEST_FRAME_SIZE, GFP_KERNEL);\ndrivers/thunderbolt/dma_test.c:713:\tif (!dma_test_pattern)\ndrivers/thunderbolt/dma_test.c-714-\t\treturn -ENOMEM;\n--\ndrivers/thunderbolt/dma_test.c-716-\tfor (i = 0; i \u003c\tDMA_TEST_FRAME_SIZE / sizeof(data_value); i++)\ndrivers/thunderbolt/dma_test.c:717:\t\t((u32 *)dma_test_pattern)[i] = data_value++;\ndrivers/thunderbolt/dma_test.c-718-\ndrivers/thunderbolt/dma_test.c:719:\tdma_test_dir = tb_property_create_dir(\u0026dma_test_dir_uuid);\ndrivers/thunderbolt/dma_test.c:720:\tif (!dma_test_dir) {\ndrivers/thunderbolt/dma_test.c-721-\t\tret = -ENOMEM;\n--\ndrivers/thunderbolt/dma_test.c-724-\ndrivers/thunderbolt/dma_test.c:725:\ttb_property_add_immediate(dma_test_dir, \"prtcid\", 1);\ndrivers/thunderbolt/dma_test.c:726:\ttb_property_add_immediate(dma_test_dir, \"prtcvers\", 1);\ndrivers/thunderbolt/dma_test.c:727:\ttb_property_add_immediate(dma_test_dir, \"prtcrevs\", 0);\ndrivers/thunderbolt/dma_test.c:728:\ttb_property_add_immediate(dma_test_dir, \"prtcstns\", 0);\ndrivers/thunderbolt/dma_test.c-729-\ndrivers/thunderbolt/dma_test.c:730:\tret = tb_register_property_dir(\"dma_test\", dma_test_dir);\ndrivers/thunderbolt/dma_test.c-731-\tif (ret)\n--\ndrivers/thunderbolt/dma_test.c-733-\ndrivers/thunderbolt/dma_test.c:734:\tret = tb_register_service_driver(\u0026dma_test_driver);\ndrivers/thunderbolt/dma_test.c-735-\tif (ret)\n--\ndrivers/thunderbolt/dma_test.c-740-err_unregister_dir:\ndrivers/thunderbolt/dma_test.c:741:\ttb_unregister_property_dir(\"dma_test\", dma_test_dir);\ndrivers/thunderbolt/dma_test.c-742-err_free_dir:\ndrivers/thunderbolt/dma_test.c:743:\ttb_property_free_dir(dma_test_dir);\ndrivers/thunderbolt/dma_test.c-744-err_free_pattern:\ndrivers/thunderbolt/dma_test.c:745:\tkfree(dma_test_pattern);\ndrivers/thunderbolt/dma_test.c-746-\n--\ndrivers/thunderbolt/dma_test.c-748-}\ndrivers/thunderbolt/dma_test.c:749:module_init(dma_test_init);\ndrivers/thunderbolt/dma_test.c-750-\ndrivers/thunderbolt/dma_test.c:751:static void __exit dma_test_exit(void)\ndrivers/thunderbolt/dma_test.c-752-{\ndrivers/thunderbolt/dma_test.c:753:\ttb_unregister_service_driver(\u0026dma_test_driver);\ndrivers/thunderbolt/dma_test.c:754:\ttb_unregister_property_dir(\"dma_test\", dma_test_dir);\ndrivers/thunderbolt/dma_test.c:755:\ttb_property_free_dir(dma_test_dir);\ndrivers/thunderbolt/dma_test.c:756:\tkfree(dma_test_pattern);\ndrivers/thunderbolt/dma_test.c-757-}\ndrivers/thunderbolt/dma_test.c:758:module_exit(dma_test_exit);\ndrivers/thunderbolt/dma_test.c-759-\n--\ndrivers/thunderbolt/dma_test.c=761=MODULE_AUTHOR(\"Mika Westerberg \u003cmika.westerberg@linux.intel.com\u003e\");\ndrivers/thunderbolt/dma_test.c:762:MODULE_DESCRIPTION(\"Thunderbolt/USB4 DMA traffic test driver\");\ndrivers/thunderbolt/dma_test.c-763-MODULE_LICENSE(\"GPL v2\");\n--\ndrivers/thunderbolt/icm.c=1240=__icm_tr_device_connected(struct tb *tb, const struct icm_pkg_header *hdr,\n--\ndrivers/thunderbolt/icm.c-1254-\t * Currently we don't use the QoS information coming with the\ndrivers/thunderbolt/icm.c:1255:\t * device connected message so simply just ignore that extra\ndrivers/thunderbolt/icm.c-1256-\t * packet for now.\n--\ndrivers/thunderbolt/icm.c=2479=struct tb *icm_probe(struct tb_nhi *nhi)\n--\ndrivers/thunderbolt/icm.c-2514-\t\t/*\ndrivers/thunderbolt/icm.c:2515:\t\t * NVM upgrade has not been tested on Apple systems and\ndrivers/thunderbolt/icm.c-2516-\t\t * they don't provide images publicly either. To be on\n--\ndrivers/thunderbolt/nhi.c=76=static void ring_interrupt_active(struct tb_ring *ring, bool active)\n--\ndrivers/thunderbolt/nhi.c-102-\t\t * to prevent conditions that may occur where two\ndrivers/thunderbolt/nhi.c:103:\t\t * MSIX interrupts are simultaneously active and\ndrivers/thunderbolt/nhi.c-104-\t\t * reading the register clears both of them.\n--\ndrivers/thunderbolt/nhi.c=1163=static struct tb *nhi_select_cm(struct tb_nhi *nhi)\n--\ndrivers/thunderbolt/nhi.c-1167-\t/*\ndrivers/thunderbolt/nhi.c:1168:\t * USB4 case is simple. If we got control of any of the\ndrivers/thunderbolt/nhi.c-1169-\t * capabilities, we use software CM.\n--\ndrivers/thunderbolt/switch.c=3641=void tb_switch_suspend(struct tb_switch *sw, bool runtime)\n--\ndrivers/thunderbolt/switch.c-3649-\t/*\n\n"
}

gemini-3.1-pro-preview

null

null

							input: 27744
							output: 27
							thoughts: 196
						

**Investigating Thunderbolt Network Driver Testing**

Okay, so I'm looking at testing the Thunderbolt network driver, specifically the `thunderbolt-net` driver, and I see a couple of existing USB4 test configurations: `USB4_KUNIT_TEST` and `USB4_DMA_TEST`. But, the real question is, can we fuzz the Thunderbolt network driver itself? It relies on Thunderbolt XDomain services, so that's the key.

My immediate thought is, can I create a mock Thunderbolt device within QEMU? Let me check for existing `usb4` or `thunderbolt` emulation within QEMU first. Darn, looks like there's no Thunderbolt controller emulation in QEMU. That's a serious roadblock.

Hold on a second, what if we can instantiate the driver through an alternate method, similar to how we have `mac80211_hwsim` or `vhci` for USB? Is there anything like a `thunderbolt_hwsim` or a similar virtualized hardware model available? It is unlikely, but let me check.

Alright, let's see if there is a way to create a mock Thunderbolt device. Time to grep the kernel sources for functions that might indicate a mock or test harness. I'll search for `tb_register_property_dir` or `tb_register_service_driver`. Hopefully, that will give me some leads.

{
  "Expression": "tb_register_service_driver",
  "PathPrefix": ""
}

{
  "Output": "drivers/net/thunderbolt/main.c=1501=static int __init tbnet_init(void)\n--\ndrivers/net/thunderbolt/main.c-1522-\ndrivers/net/thunderbolt/main.c:1523:\tret = tb_register_service_driver(\u0026tbnet_driver);\ndrivers/net/thunderbolt/main.c-1524-\tif (ret)\n--\ndrivers/thunderbolt/dma_test.c=707=static int __init dma_test_init(void)\n--\ndrivers/thunderbolt/dma_test.c-733-\ndrivers/thunderbolt/dma_test.c:734:\tret = tb_register_service_driver(\u0026dma_test_driver);\ndrivers/thunderbolt/dma_test.c-735-\tif (ret)\n--\ndrivers/thunderbolt/stream.c=1648=static int __init tbstream_init(void)\n--\ndrivers/thunderbolt/stream.c-1669-\ndrivers/thunderbolt/stream.c:1670:\tret = tb_register_service_driver(\u0026tbstream_driver);\ndrivers/thunderbolt/stream.c-1671-\tif (ret)\n--\ndrivers/thunderbolt/xdomain.c=939=tb_xdp_schedule_request(struct tb *tb, const struct tb_xdp_header *hdr,\n--\ndrivers/thunderbolt/xdomain.c-961-/**\ndrivers/thunderbolt/xdomain.c:962: * tb_register_service_driver() - Register XDomain service driver\ndrivers/thunderbolt/xdomain.c-963- * @drv: Driver to register\n--\ndrivers/thunderbolt/xdomain.c-968- */\ndrivers/thunderbolt/xdomain.c:969:int tb_register_service_driver(struct tb_service_driver *drv)\ndrivers/thunderbolt/xdomain.c-970-{\n--\ndrivers/thunderbolt/xdomain.c-973-}\ndrivers/thunderbolt/xdomain.c:974:EXPORT_SYMBOL_GPL(tb_register_service_driver);\ndrivers/thunderbolt/xdomain.c-975-\n--\ninclude/linux/thunderbolt.h=466=struct tb_service_driver {\n--\ninclude/linux/thunderbolt.h-479-\ninclude/linux/thunderbolt.h:480:int tb_register_service_driver(struct tb_service_driver *drv);\ninclude/linux/thunderbolt.h-481-void tb_unregister_service_driver(struct tb_service_driver *drv);\n"
}

gemini-3.1-pro-preview

null

null

							input: 28926
							output: 25
							thoughts: 173
						

**Analyzing the Thunderbolt Driver Security Landscape**

Okay, so I'm digging into this Thunderbolt driver situation, and the immediate impression is that there isn't an obvious "mock driver" present. From what I can see, `tb_register_service_driver` seems exclusively called by `tbnet`, `dma_test`, and `stream`. My initial concern is how easily it can be reached. But, wait... could `tbnet` be fuzzable through a secondary pathway?

Now, considering scenarios where Thunderbolt hardware might be absent... If there's no Thunderbolt hardware to begin with, the `thunderbolt` driver won't probe any controllers. That's a given. And if no controllers are probed, it logically follows that no `tb_service` devices are created. The ripple effect continues: if no `tb_service` devices are created, `tbnet_probe` – which is key to triggering the `tbnet` driver – is never invoked. This suggests that the `tbnet` driver, at least in certain configurations, might be entirely unreachable. That's a huge potential security hole, assuming it can't be reached.

So, the next logical step is to explore whether a user-space process can somehow create a `tb_service` device. My focus will be on searching for calls like `tb_service_create` or something with a similar naming convention to see if such a thing exists. If I can find a way to create one from userspace, that opens up all sorts of fuzzing possibilities.

no matches

{
  "Expression": "tb_service_create",
  "PathPrefix": ""
}

{
  "error": "no matches"
}

gemini-3.1-pro-preview

null

null

							input: 29461
							output: 36
							thoughts: 28
						

Okay, here's my take on those thoughts, tailored for an expert audience:

**Investigating Thunderbolt Device Registration**

Alright, I need to get to the bottom of how these Thunderbolt devices are being registered within the xdomain context. My first instinct, given my experience, is to head directly into the relevant driver code. Specifically, `drivers/thunderbolt/xdomain.c` looks like the prime suspect for this kind of low-level device interaction. I'm going to quickly use `grep` to look for the key functions that typically handle device registration with the kernel. I'll search for `device_register` and `device_add`. These are the obvious starting points when looking at how a device is brought into the system and its device tree. This approach will allow me to zero in on the relevant sections of the code immediately. I'm hoping to quickly identify the points where the Thunderbolt device is identified, initialized, and integrated within the kernel's device management infrastructure. From there I can track the control flow from this point.

{
  "Expression": "device_add|device_register",
  "PathPrefix": "drivers/thunderbolt/xdomain.c"
}

{
  "Output": "drivers/thunderbolt/xdomain.c=1219=static void enumerate_services(struct tb_xdomain *xd)\n--\ndrivers/thunderbolt/xdomain.c-1268-\ndrivers/thunderbolt/xdomain.c:1269:\t\tif (device_register(\u0026svc-\u003edev)) {\ndrivers/thunderbolt/xdomain.c-1270-\t\t\ttb_service_debugfs_remove(svc);\n--\ndrivers/thunderbolt/xdomain.c=1536=static int tb_xdomain_get_properties(struct tb_xdomain *xd)\n--\ndrivers/thunderbolt/xdomain.c-1623-\ndrivers/thunderbolt/xdomain.c:1624:\t\tif (device_add(\u0026xd-\u003edev)) {\ndrivers/thunderbolt/xdomain.c-1625-\t\t\tdev_err(\u0026xd-\u003edev, \"failed to add XDomain device\\n\");\n"
}

gemini-3.1-pro-preview

null

null

							input: 29976
							output: 31
							thoughts: 116
						

**Tracing the Lifecycle of Service Enumeration**

Okay, so I'm trying to wrap my head around how these services are being enumerated. The `enumerate_services` function is the key here, it's what actually creates those `tb_service` devices. I need to understand the call chain to see what triggers it.

It looks like `enumerate_services` gets called either directly from `tb_xdomain_get_properties` or when properties have changed, `tb_xdomain_properties_changed`. Now, `tb_xdomain_get_properties` itself is called from `tb_xdomain_get_properties_work` which is interesting because that likely means it's not a direct, synchronous call but something deferred. `tb_xdomain_get_properties_work` is scheduled, which implies it's queued or triggered by some sort of event, and that's coming from `tb_xdomain_add`. So far so good. Finally, the critical point: `tb_xdomain_add` is the calling function to be called from`tb_xdomain_alloc`. 

So, I need to look into who calls `tb_xdomain_alloc`. That's where I need to start digging now to completely follow the initialization sequence.

{
  "Expression": "tb_xdomain_alloc",
  "PathPrefix": "drivers/thunderbolt/"
}

{
  "Output": "drivers/thunderbolt/dma_test.c=134=static int dma_test_start_rings(struct dma_test *dt)\n--\ndrivers/thunderbolt/dma_test.c-159-\ndrivers/thunderbolt/dma_test.c:160:\t\tret = tb_xdomain_alloc_out_hopid(xd, -1);\ndrivers/thunderbolt/dma_test.c-161-\t\tif (ret \u003c 0) {\n--\ndrivers/thunderbolt/dma_test.c-187-\ndrivers/thunderbolt/dma_test.c:188:\t\tret = tb_xdomain_alloc_in_hopid(xd, -1);\ndrivers/thunderbolt/dma_test.c-189-\t\tif (ret \u003c 0) {\n--\ndrivers/thunderbolt/icm.c=709=static void add_xdomain(struct tb_switch *sw, u64 route,\n--\ndrivers/thunderbolt/icm.c-716-\ndrivers/thunderbolt/icm.c:717:\txd = tb_xdomain_alloc(sw-\u003etb, \u0026sw-\u003edev, route, local_uuid, remote_uuid);\ndrivers/thunderbolt/icm.c-718-\tif (!xd)\n--\ndrivers/thunderbolt/stream.c=1035=static int tbstream_dev_alloc_in_hopid(struct tbstream_dev *sdev, int hopid)\n--\ndrivers/thunderbolt/stream.c-1045-\t}\ndrivers/thunderbolt/stream.c:1046:\tret = tb_xdomain_alloc_in_hopid(xd, hopid);\ndrivers/thunderbolt/stream.c-1047-\tif (ret \u003c 0)\n--\ndrivers/thunderbolt/stream.c=1061=static int tbstream_dev_alloc_out_hopid(struct tbstream_dev *sdev, int hopid)\n--\ndrivers/thunderbolt/stream.c-1071-\t}\ndrivers/thunderbolt/stream.c:1072:\tret = tb_xdomain_alloc_out_hopid(xd, hopid);\ndrivers/thunderbolt/stream.c-1073-\tif (ret \u003c 0)\n--\ndrivers/thunderbolt/tb.c=431=static void tb_scan_xdomain(struct tb_port *port)\n--\ndrivers/thunderbolt/tb.c-447-\ndrivers/thunderbolt/tb.c:448:\txd = tb_xdomain_alloc(tb, \u0026sw-\u003edev, route, tb-\u003eroot_switch-\u003euuid,\ndrivers/thunderbolt/tb.c-449-\t\t\t      NULL);\n--\ndrivers/thunderbolt/tb.h=1260=bool tb_xdomain_handle_request(struct tb *tb, enum tb_cfg_pkg_type type,\ndrivers/thunderbolt/tb.h-1261-\t\t\t       const void *buf, size_t size);\ndrivers/thunderbolt/tb.h:1262:struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,\ndrivers/thunderbolt/tb.h-1263-\t\t\t\t    u64 route, const uuid_t *local_uuid,\n--\ndrivers/thunderbolt/xdomain.c=2074=static void tb_xdomain_link_exit(struct tb_xdomain *xd)\n--\ndrivers/thunderbolt/xdomain.c-2107-/**\ndrivers/thunderbolt/xdomain.c:2108: * tb_xdomain_alloc() - Allocate new XDomain object\ndrivers/thunderbolt/xdomain.c-2109- * @tb: Domain where the XDomain belongs\n--\ndrivers/thunderbolt/xdomain.c-2120- */\ndrivers/thunderbolt/xdomain.c:2121:struct tb_xdomain *tb_xdomain_alloc(struct tb *tb, struct device *parent,\ndrivers/thunderbolt/xdomain.c-2122-\t\t\t\t    u64 route, const uuid_t *local_uuid,\n--\ndrivers/thunderbolt/xdomain.c=2348=EXPORT_SYMBOL_GPL(tb_xdomain_lane_bonding_disable);\n--\ndrivers/thunderbolt/xdomain.c-2350-/**\ndrivers/thunderbolt/xdomain.c:2351: * tb_xdomain_alloc_in_hopid() - Allocate input HopID for tunneling\ndrivers/thunderbolt/xdomain.c-2352- * @xd: XDomain connection\n--\ndrivers/thunderbolt/xdomain.c-2363- */\ndrivers/thunderbolt/xdomain.c:2364:int tb_xdomain_alloc_in_hopid(struct tb_xdomain *xd, int hopid)\ndrivers/thunderbolt/xdomain.c-2365-{\n--\ndrivers/thunderbolt/xdomain.c-2373-}\ndrivers/thunderbolt/xdomain.c:2374:EXPORT_SYMBOL_GPL(tb_xdomain_alloc_in_hopid);\ndrivers/thunderbolt/xdomain.c-2375-\ndrivers/thunderbolt/xdomain.c-2376-/**\ndrivers/thunderbolt/xdomain.c:2377: * tb_xdomain_alloc_out_hopid() - Allocate output HopID for tunneling\ndrivers/thunderbolt/xdomain.c-2378- * @xd: XDomain connection\n--\ndrivers/thunderbolt/xdomain.c-2389- */\ndrivers/thunderbolt/xdomain.c:2390:int tb_xdomain_alloc_out_hopid(struct tb_xdomain *xd, int hopid)\ndrivers/thunderbolt/xdomain.c-2391-{\n--\ndrivers/thunderbolt/xdomain.c-2399-}\ndrivers/thunderbolt/xdomain.c:2400:EXPORT_SYMBOL_GPL(tb_xdomain_alloc_out_hopid);\ndrivers/thunderbolt/xdomain.c-2401-\n"
}

gemini-3.1-pro-preview

null

null

							input: 31892
							output: 27
							thoughts: 114
						

**Thunderbolt Driver Emulation Hunt**

Okay, so `tb_xdomain_alloc` is used by `add_xdomain` in `icm.c` and `tb_scan_xdomain` in `tb.c`. That places it firmly within the core Thunderbolt driver's hardware port scanning functionality, so it makes sense that I'm seeing it. The real question is, can I get some kind of emulation for this stuff? I need to test without real hardware. Hmm, I vaguely recall something related to `usb4_kunit_test`. That sounds promising. Let's see if there's any Thunderbolt-specific software emulation available. I'll search the `drivers/thunderbolt/` directory for anything mentioning `kunit`. That's probably the best bet.

{
  "Expression": "kunit",
  "PathPrefix": "drivers/thunderbolt/"
}

{
  "Output": "drivers/thunderbolt/test.c-8-\ndrivers/thunderbolt/test.c:9:#include \u003ckunit/test.h\u003e\ndrivers/thunderbolt/test.c-10-#include \u003clinux/idr.h\u003e\n--\ndrivers/thunderbolt/test.c-14-\ndrivers/thunderbolt/test.c:15:static int __ida_init(struct kunit_resource *res, void *context)\ndrivers/thunderbolt/test.c-16-{\n--\ndrivers/thunderbolt/test.c-23-\ndrivers/thunderbolt/test.c:24:static void __ida_destroy(struct kunit_resource *res)\ndrivers/thunderbolt/test.c-25-{\n--\ndrivers/thunderbolt/test.c-30-\ndrivers/thunderbolt/test.c:31:static void kunit_ida_init(struct kunit *test, struct ida *ida)\ndrivers/thunderbolt/test.c-32-{\ndrivers/thunderbolt/test.c:33:\tkunit_alloc_resource(test, __ida_init, __ida_destroy, GFP_KERNEL, ida);\ndrivers/thunderbolt/test.c-34-}\ndrivers/thunderbolt/test.c-35-\ndrivers/thunderbolt/test.c:36:static struct tb_switch *alloc_switch(struct kunit *test, u64 route,\ndrivers/thunderbolt/test.c-37-\t\t\t\t      u8 upstream_port, u8 max_port_number)\n--\ndrivers/thunderbolt/test.c-42-\ndrivers/thunderbolt/test.c:43:\tsw = kunit_kzalloc(test, sizeof(*sw), GFP_KERNEL);\ndrivers/thunderbolt/test.c-44-\tif (!sw)\n--\ndrivers/thunderbolt/test.c-54-\tsize = (sw-\u003econfig.max_port_number + 1) * sizeof(*sw-\u003eports);\ndrivers/thunderbolt/test.c:55:\tsw-\u003eports = kunit_kzalloc(test, size, GFP_KERNEL);\ndrivers/thunderbolt/test.c-56-\tif (!sw-\u003eports)\n--\ndrivers/thunderbolt/test.c-63-\t\tif (i) {\ndrivers/thunderbolt/test.c:64:\t\t\tkunit_ida_init(test, \u0026sw-\u003eports[i].in_hopids);\ndrivers/thunderbolt/test.c:65:\t\t\tkunit_ida_init(test, \u0026sw-\u003eports[i].out_hopids);\ndrivers/thunderbolt/test.c-66-\t\t}\n--\ndrivers/thunderbolt/test.c-71-\ndrivers/thunderbolt/test.c:72:static struct tb_switch *alloc_host(struct kunit *test)\ndrivers/thunderbolt/test.c-73-{\n--\ndrivers/thunderbolt/test.c-153-\ndrivers/thunderbolt/test.c:154:static struct tb_switch *alloc_host_usb4(struct kunit *test)\ndrivers/thunderbolt/test.c-155-{\n--\ndrivers/thunderbolt/test.c-172-\ndrivers/thunderbolt/test.c:173:static struct tb_switch *alloc_host_br(struct kunit *test)\ndrivers/thunderbolt/test.c-174-{\n--\ndrivers/thunderbolt/test.c-189-\ndrivers/thunderbolt/test.c:190:static struct tb_switch *alloc_dev_default(struct kunit *test,\ndrivers/thunderbolt/test.c-191-\t\t\t\t\t   struct tb_switch *parent,\n--\ndrivers/thunderbolt/test.c-339-\ndrivers/thunderbolt/test.c:340:static struct tb_switch *alloc_dev_with_dpin(struct kunit *test,\ndrivers/thunderbolt/test.c-341-\t\t\t\t\t     struct tb_switch *parent,\n--\ndrivers/thunderbolt/test.c-360-\ndrivers/thunderbolt/test.c:361:static struct tb_switch *alloc_dev_without_dp(struct kunit *test,\ndrivers/thunderbolt/test.c-362-\t\t\t\t\t      struct tb_switch *parent,\n--\ndrivers/thunderbolt/test.c-401-\ndrivers/thunderbolt/test.c:402:static struct tb_switch *alloc_dev_usb4(struct kunit *test,\ndrivers/thunderbolt/test.c-403-\t\t\t\t\tstruct tb_switch *parent,\n--\ndrivers/thunderbolt/test.c-422-\ndrivers/thunderbolt/test.c:423:static void tb_test_path_basic(struct kunit *test)\ndrivers/thunderbolt/test.c-424-{\n--\ndrivers/thunderbolt/test.c-439-\ndrivers/thunderbolt/test.c:440:static void tb_test_path_not_connected_walk(struct kunit *test)\ndrivers/thunderbolt/test.c-441-{\n--\ndrivers/thunderbolt/test.c=473=struct port_expectation {\n--\ndrivers/thunderbolt/test.c-478-\ndrivers/thunderbolt/test.c:479:static void tb_test_path_single_hop_walk(struct kunit *test)\ndrivers/thunderbolt/test.c-480-{\n--\ndrivers/thunderbolt/test.c-532-\ndrivers/thunderbolt/test.c:533:static void tb_test_path_daisy_chain_walk(struct kunit *test)\ndrivers/thunderbolt/test.c-534-{\n--\ndrivers/thunderbolt/test.c-591-\ndrivers/thunderbolt/test.c:592:static void tb_test_path_simple_tree_walk(struct kunit *test)\ndrivers/thunderbolt/test.c-593-{\n--\ndrivers/thunderbolt/test.c-654-\ndrivers/thunderbolt/test.c:655:static void tb_test_path_complex_tree_walk(struct kunit *test)\ndrivers/thunderbolt/test.c-656-{\n--\ndrivers/thunderbolt/test.c-738-\ndrivers/thunderbolt/test.c:739:static void tb_test_path_max_length_walk(struct kunit *test)\ndrivers/thunderbolt/test.c-740-{\n--\ndrivers/thunderbolt/test.c-841-\ndrivers/thunderbolt/test.c:842:static void tb_test_path_not_connected(struct kunit *test)\ndrivers/thunderbolt/test.c-843-{\n--\ndrivers/thunderbolt/test.c=862=struct hop_expectation {\n--\ndrivers/thunderbolt/test.c-869-\ndrivers/thunderbolt/test.c:870:static void tb_test_path_not_bonded_lane0(struct kunit *test)\ndrivers/thunderbolt/test.c-871-{\n--\ndrivers/thunderbolt/test.c-927-\ndrivers/thunderbolt/test.c:928:static void tb_test_path_not_bonded_lane1(struct kunit *test)\ndrivers/thunderbolt/test.c-929-{\n--\ndrivers/thunderbolt/test.c-989-\ndrivers/thunderbolt/test.c:990:static void tb_test_path_not_bonded_lane1_chain(struct kunit *test)\ndrivers/thunderbolt/test.c-991-{\n--\ndrivers/thunderbolt/test.c-1069-\ndrivers/thunderbolt/test.c:1070:static void tb_test_path_not_bonded_lane1_chain_reverse(struct kunit *test)\ndrivers/thunderbolt/test.c-1071-{\n--\ndrivers/thunderbolt/test.c-1149-\ndrivers/thunderbolt/test.c:1150:static void tb_test_path_mixed_chain(struct kunit *test)\ndrivers/thunderbolt/test.c-1151-{\n--\ndrivers/thunderbolt/test.c-1241-\ndrivers/thunderbolt/test.c:1242:static void tb_test_path_mixed_chain_reverse(struct kunit *test)\ndrivers/thunderbolt/test.c-1243-{\n--\ndrivers/thunderbolt/test.c-1333-\ndrivers/thunderbolt/test.c:1334:static void tb_test_tunnel_pcie(struct kunit *test)\ndrivers/thunderbolt/test.c-1335-{\n--\ndrivers/thunderbolt/test.c-1388-\ndrivers/thunderbolt/test.c:1389:static void tb_test_tunnel_dp(struct kunit *test)\ndrivers/thunderbolt/test.c-1390-{\n--\ndrivers/thunderbolt/test.c-1426-\ndrivers/thunderbolt/test.c:1427:static void tb_test_tunnel_dp_chain(struct kunit *test)\ndrivers/thunderbolt/test.c-1428-{\n--\ndrivers/thunderbolt/test.c-1472-\ndrivers/thunderbolt/test.c:1473:static void tb_test_tunnel_dp_tree(struct kunit *test)\ndrivers/thunderbolt/test.c-1474-{\n--\ndrivers/thunderbolt/test.c-1522-\ndrivers/thunderbolt/test.c:1523:static void tb_test_tunnel_dp_max_length(struct kunit *test)\ndrivers/thunderbolt/test.c-1524-{\n--\ndrivers/thunderbolt/test.c-1602-\ndrivers/thunderbolt/test.c:1603:static void tb_test_tunnel_3dp(struct kunit *test)\ndrivers/thunderbolt/test.c-1604-{\n--\ndrivers/thunderbolt/test.c-1668-\ndrivers/thunderbolt/test.c:1669:static void tb_test_tunnel_usb3(struct kunit *test)\ndrivers/thunderbolt/test.c-1670-{\n--\ndrivers/thunderbolt/test.c-1723-\ndrivers/thunderbolt/test.c:1724:static void tb_test_tunnel_port_on_path(struct kunit *test)\ndrivers/thunderbolt/test.c-1725-{\n--\ndrivers/thunderbolt/test.c-1789-\ndrivers/thunderbolt/test.c:1790:static void tb_test_tunnel_dma(struct kunit *test)\ndrivers/thunderbolt/test.c-1791-{\n--\ndrivers/thunderbolt/test.c-1832-\ndrivers/thunderbolt/test.c:1833:static void tb_test_tunnel_dma_rx(struct kunit *test)\ndrivers/thunderbolt/test.c-1834-{\n--\ndrivers/thunderbolt/test.c-1869-\ndrivers/thunderbolt/test.c:1870:static void tb_test_tunnel_dma_tx(struct kunit *test)\ndrivers/thunderbolt/test.c-1871-{\n--\ndrivers/thunderbolt/test.c-1906-\ndrivers/thunderbolt/test.c:1907:static void tb_test_tunnel_dma_chain(struct kunit *test)\ndrivers/thunderbolt/test.c-1908-{\n--\ndrivers/thunderbolt/test.c-1972-\ndrivers/thunderbolt/test.c:1973:static void tb_test_tunnel_dma_match(struct kunit *test)\ndrivers/thunderbolt/test.c-1974-{\n--\ndrivers/thunderbolt/test.c-2023-\ndrivers/thunderbolt/test.c:2024:static void tb_test_credit_alloc_legacy_not_bonded(struct kunit *test)\ndrivers/thunderbolt/test.c-2025-{\n--\ndrivers/thunderbolt/test.c-2056-\ndrivers/thunderbolt/test.c:2057:static void tb_test_credit_alloc_legacy_bonded(struct kunit *test)\ndrivers/thunderbolt/test.c-2058-{\n--\ndrivers/thunderbolt/test.c-2089-\ndrivers/thunderbolt/test.c:2090:static void tb_test_credit_alloc_pcie(struct kunit *test)\ndrivers/thunderbolt/test.c-2091-{\n--\ndrivers/thunderbolt/test.c-2122-\ndrivers/thunderbolt/test.c:2123:static void tb_test_credit_alloc_without_dp(struct kunit *test)\ndrivers/thunderbolt/test.c-2124-{\n--\ndrivers/thunderbolt/test.c-2172-\ndrivers/thunderbolt/test.c:2173:static void tb_test_credit_alloc_dp(struct kunit *test)\ndrivers/thunderbolt/test.c-2174-{\n--\ndrivers/thunderbolt/test.c-2216-\ndrivers/thunderbolt/test.c:2217:static void tb_test_credit_alloc_usb3(struct kunit *test)\ndrivers/thunderbolt/test.c-2218-{\n--\ndrivers/thunderbolt/test.c-2249-\ndrivers/thunderbolt/test.c:2250:static void tb_test_credit_alloc_dma(struct kunit *test)\ndrivers/thunderbolt/test.c-2251-{\n--\ndrivers/thunderbolt/test.c-2285-\ndrivers/thunderbolt/test.c:2286:static void tb_test_credit_alloc_dma_multiple(struct kunit *test)\ndrivers/thunderbolt/test.c-2287-{\n--\ndrivers/thunderbolt/test.c-2382-\ndrivers/thunderbolt/test.c:2383:static struct tb_tunnel *TB_TEST_PCIE_TUNNEL(struct kunit *test,\ndrivers/thunderbolt/test.c-2384-\t\t\tstruct tb_switch *host, struct tb_switch *dev)\n--\ndrivers/thunderbolt/test.c-2412-\ndrivers/thunderbolt/test.c:2413:static struct tb_tunnel *TB_TEST_DP_TUNNEL1(struct kunit *test,\ndrivers/thunderbolt/test.c-2414-\t\t\tstruct tb_switch *host, struct tb_switch *dev)\n--\ndrivers/thunderbolt/test.c-2449-\ndrivers/thunderbolt/test.c:2450:static struct tb_tunnel *TB_TEST_DP_TUNNEL2(struct kunit *test,\ndrivers/thunderbolt/test.c-2451-\t\t\tstruct tb_switch *host, struct tb_switch *dev)\n--\ndrivers/thunderbolt/test.c-2486-\ndrivers/thunderbolt/test.c:2487:static struct tb_tunnel *TB_TEST_USB3_TUNNEL(struct kunit *test,\ndrivers/thunderbolt/test.c-2488-\t\t\tstruct tb_switch *host, struct tb_switch *dev)\n--\ndrivers/thunderbolt/test.c-2516-\ndrivers/thunderbolt/test.c:2517:static struct tb_tunnel *TB_TEST_DMA_TUNNEL1(struct kunit *test,\ndrivers/thunderbolt/test.c-2518-\t\t\tstruct tb_switch *host, struct tb_switch *dev)\n--\ndrivers/thunderbolt/test.c-2546-\ndrivers/thunderbolt/test.c:2547:static struct tb_tunnel *TB_TEST_DMA_TUNNEL2(struct kunit *test,\ndrivers/thunderbolt/test.c-2548-\t\t\tstruct tb_switch *host, struct tb_switch *dev)\n--\ndrivers/thunderbolt/test.c-2576-\ndrivers/thunderbolt/test.c:2577:static void tb_test_credit_alloc_all(struct kunit *test)\ndrivers/thunderbolt/test.c-2578-{\n--\ndrivers/thunderbolt/test.c=2663=static const uuid_t network_dir_uuid =\n--\ndrivers/thunderbolt/test.c-2666-\ndrivers/thunderbolt/test.c:2667:static void tb_test_property_parse(struct kunit *test)\ndrivers/thunderbolt/test.c-2668-{\n--\ndrivers/thunderbolt/test.c-2726-\ndrivers/thunderbolt/test.c:2727:static void tb_test_property_format(struct kunit *test)\ndrivers/thunderbolt/test.c-2728-{\n--\ndrivers/thunderbolt/test.c-2741-\ndrivers/thunderbolt/test.c:2742:\tblock = kunit_kzalloc(test, block_len * sizeof(u32), GFP_KERNEL);\ndrivers/thunderbolt/test.c-2743-\tKUNIT_ASSERT_NOT_NULL(test, block);\n--\ndrivers/thunderbolt/test.c-2753-\ndrivers/thunderbolt/test.c:2754:static void compare_dirs(struct kunit *test, struct tb_property_dir *d1,\ndrivers/thunderbolt/test.c-2755-\t\t\t struct tb_property_dir *d2)\n--\ndrivers/thunderbolt/test.c-2823-\ndrivers/thunderbolt/test.c:2824:static void tb_test_property_copy(struct kunit *test)\ndrivers/thunderbolt/test.c-2825-{\n--\ndrivers/thunderbolt/test.c-2842-\ndrivers/thunderbolt/test.c:2843:\tblock = kunit_kzalloc(test, sizeof(root_directory), GFP_KERNEL);\ndrivers/thunderbolt/test.c-2844-\tKUNIT_ASSERT_NOT_NULL(test, block);\n--\ndrivers/thunderbolt/test.c-2867-\ndrivers/thunderbolt/test.c:2868:static void tb_test_property_parse_u32_wrap(struct kunit *test)\ndrivers/thunderbolt/test.c-2869-{\n--\ndrivers/thunderbolt/test.c-2875-\t */\ndrivers/thunderbolt/test.c:2876:\tu32 *block = kunit_kzalloc(test, 0x102 * sizeof(u32), GFP_KERNEL);\ndrivers/thunderbolt/test.c-2877-\tstruct tb_property_dir *dir;\n--\ndrivers/thunderbolt/test.c-2898-\ndrivers/thunderbolt/test.c:2899:static void tb_test_property_parse_recursion(struct kunit *test)\ndrivers/thunderbolt/test.c-2900-{\n--\ndrivers/thunderbolt/test.c-2907-\t */\ndrivers/thunderbolt/test.c:2908:\tu32 *block = kunit_kzalloc(test, 10 * sizeof(u32), GFP_KERNEL);\ndrivers/thunderbolt/test.c-2909-\tstruct tb_property_dir *dir;\n--\ndrivers/thunderbolt/test.c-2938-\ndrivers/thunderbolt/test.c:2939:static void tb_test_property_parse_dir_len_underflow(struct kunit *test)\ndrivers/thunderbolt/test.c-2940-{\n--\ndrivers/thunderbolt/test.c-2952-\t */\ndrivers/thunderbolt/test.c:2953:\tu32 *block = kunit_kzalloc(test, 7 * sizeof(u32), GFP_KERNEL);\ndrivers/thunderbolt/test.c-2954-\tstruct tb_property_dir *dir;\n--\ndrivers/thunderbolt/test.c-2978-\ndrivers/thunderbolt/test.c:2979:static void tb_test_property_parse_zero_length(struct kunit *test)\ndrivers/thunderbolt/test.c-2980-{\ndrivers/thunderbolt/test.c:2981:\tu32 *block = kunit_kzalloc(test, 6 * sizeof(u32), GFP_KERNEL);\ndrivers/thunderbolt/test.c-2982-\tstruct tb_property_dir *dir;\n--\ndrivers/thunderbolt/test.c-2998-\ndrivers/thunderbolt/test.c:2999:static void tb_test_property_parse_rootdir_overflow(struct kunit *test)\ndrivers/thunderbolt/test.c-3000-{\ndrivers/thunderbolt/test.c:3001:\tu32 *block = kunit_kzalloc(test, 4 * sizeof(u32), GFP_KERNEL);\ndrivers/thunderbolt/test.c-3002-\tstruct tb_property_dir *dir;\n--\ndrivers/thunderbolt/test.c-3016-\ndrivers/thunderbolt/test.c:3017:static void tb_test_property_merge(struct kunit *test)\ndrivers/thunderbolt/test.c-3018-{\n--\ndrivers/thunderbolt/test.c-3097-\ndrivers/thunderbolt/test.c:3098:static struct kunit_case tb_test_cases[] = {\ndrivers/thunderbolt/test.c-3099-\tKUNIT_CASE(tb_test_property_parse_u32_wrap),\n--\ndrivers/thunderbolt/test.c-3146-\ndrivers/thunderbolt/test.c:3147:static struct kunit_suite tb_test_suite = {\ndrivers/thunderbolt/test.c-3148-\t.name = \"thunderbolt\",\n--\ndrivers/thunderbolt/test.c-3151-\ndrivers/thunderbolt/test.c:3152:kunit_test_suite(tb_test_suite);\n"
}

gemini-3.1-pro-preview

null

null

							input: 37669
							output: 27
							thoughts: 402
						

**Analyzing the Thunderbolt Network Fuzzing Conundrum**

Okay, so I'm looking at this `test.c` file, and it's pretty clear it's just a KUnit test suite for the thunderbolt core. It doesn't actually instantiate or register a mock Thunderbolt controller, which is the crux of the problem. This means `thunderbolt-net` can't be fuzzed in a QEMU environment as is because there's simply no controller emulation. 

Hmm, I wonder, is there another way to load and test `thunderbolt-net` without a real controller emulation? `tbnet` registers a network device, sure, but that registration hinges on `tbnet_probe` being invoked. And `tbnet_probe` gets called when the thunderbolt bus matches a `tb_service` device. And a `tb_service` device? The thunderbolt core creates *those* when it discovers a thunderbolt device with XDomain properties. Which, of course, requires a thunderbolt controller to be present to facilitate device discovery. 

Right, so in a virtual environment like GCE or QEMU, since there is no thunderbolt controller emulation, the thunderbolt core won't find any controllers, won't discover any devices, won't create those critical `tb_service` devices, and ultimately, `tbnet_probe` will *never* be called. It appears that the code in `drivers/net/thunderbolt/main.c` is completely unreachable under these circumstances.

Let me just double-check, though. Is there *any* kind of software Thunderbolt controller equivalent out there? A `mac80211_hwsim` for thunderbolt, perhaps? I did a quick `grep` for `kunit|test|mock|sim` in `drivers/thunderbolt/`, and I only see `test.c` and `dma_test.c`, which, while it does bind to a `tb_service`, looks to be another test driver. So, no, there isn't anything like `hwsim` or `vhci` for thunderbolt that I can see.

Wait, what about `configfs`? Could we somehow create a `tb_service` device that way? Let me investigate `configfs`'s relationship to thunderbolt...

{
  "Expression": "configfs",
  "PathPrefix": "drivers/thunderbolt/"
}

{
  "Output": "drivers/thunderbolt/Makefile=9=thunderbolt-$(CONFIG_DEBUG_FS) += debugfs.o\ndrivers/thunderbolt/Makefile:10:thunderbolt-$(CONFIG_USB4_CONFIGFS) += configfs.o\ndrivers/thunderbolt/Makefile-11-thunderbolt-${CONFIG_USB4_KUNIT_TEST} += test.o\n--\ndrivers/thunderbolt/configfs.c-8-\ndrivers/thunderbolt/configfs.c:9:#include \u003clinux/configfs.h\u003e\ndrivers/thunderbolt/configfs.c-10-#include \u003clinux/export.h\u003e\n--\ndrivers/thunderbolt/configfs.c=14=static const struct config_item_type tb_root_group_type = {\n--\ndrivers/thunderbolt/configfs.c-17-\ndrivers/thunderbolt/configfs.c:18:static struct configfs_subsystem tb_configfs = {\ndrivers/thunderbolt/configfs.c-19-\t.su_group = {\n--\ndrivers/thunderbolt/configfs.c-27-/**\ndrivers/thunderbolt/configfs.c:28: * tb_configfs_register_group() - Register Thunderbolt ConfigFS group\ndrivers/thunderbolt/configfs.c-29- * @group: Group to register.\n--\ndrivers/thunderbolt/configfs.c-34- */\ndrivers/thunderbolt/configfs.c:35:int tb_configfs_register_group(struct config_group *group)\ndrivers/thunderbolt/configfs.c-36-{\ndrivers/thunderbolt/configfs.c:37:\treturn configfs_register_group(\u0026tb_configfs.su_group, group);\ndrivers/thunderbolt/configfs.c-38-}\ndrivers/thunderbolt/configfs.c:39:EXPORT_SYMBOL_GPL(tb_configfs_register_group);\ndrivers/thunderbolt/configfs.c-40-\ndrivers/thunderbolt/configfs.c-41-/**\ndrivers/thunderbolt/configfs.c:42: * tb_configfs_unregister_group() - Unregister previously registered group\ndrivers/thunderbolt/configfs.c-43- * @group: Group to unregister.\ndrivers/thunderbolt/configfs.c-44- */\ndrivers/thunderbolt/configfs.c:45:void tb_configfs_unregister_group(struct config_group *group)\ndrivers/thunderbolt/configfs.c-46-{\ndrivers/thunderbolt/configfs.c:47:\tconfigfs_unregister_group(group);\ndrivers/thunderbolt/configfs.c-48-}\ndrivers/thunderbolt/configfs.c:49:EXPORT_SYMBOL_GPL(tb_configfs_unregister_group);\ndrivers/thunderbolt/configfs.c-50-\ndrivers/thunderbolt/configfs.c:51:int tb_configfs_init(void)\ndrivers/thunderbolt/configfs.c-52-{\ndrivers/thunderbolt/configfs.c:53:\tconfig_group_init(\u0026tb_configfs.su_group);\ndrivers/thunderbolt/configfs.c:54:\tmutex_init(\u0026tb_configfs.su_mutex);\ndrivers/thunderbolt/configfs.c:55:\treturn configfs_register_subsystem(\u0026tb_configfs);\ndrivers/thunderbolt/configfs.c-56-}\ndrivers/thunderbolt/configfs.c-57-\ndrivers/thunderbolt/configfs.c:58:void tb_configfs_exit(void)\ndrivers/thunderbolt/configfs.c-59-{\ndrivers/thunderbolt/configfs.c:60:\tconfigfs_unregister_subsystem(\u0026tb_configfs);\ndrivers/thunderbolt/configfs.c-61-}\n--\ndrivers/thunderbolt/domain.c=886=int tb_domain_init(void)\n--\ndrivers/thunderbolt/domain.c-889-\ndrivers/thunderbolt/domain.c:890:\ttb_configfs_init();\ndrivers/thunderbolt/domain.c-891-\ttb_debugfs_init();\n--\ndrivers/thunderbolt/domain.c=912=void tb_domain_exit(void)\n--\ndrivers/thunderbolt/domain.c-919-\ttb_debugfs_exit();\ndrivers/thunderbolt/domain.c:920:\ttb_configfs_exit();\ndrivers/thunderbolt/domain.c-921-}\n--\ndrivers/thunderbolt/stream.c-11-\ndrivers/thunderbolt/stream.c:12:#include \u003clinux/configfs.h\u003e\ndrivers/thunderbolt/stream.c-13-#include \u003clinux/file.h\u003e\n--\ndrivers/thunderbolt/stream.c=1208=CONFIGFS_ATTR(tbstream_dev_, throttling);\ndrivers/thunderbolt/stream.c-1209-\ndrivers/thunderbolt/stream.c:1210:static struct configfs_attribute *tbstream_dev_attrs[] = {\ndrivers/thunderbolt/stream.c-1211-\t\u0026tbstream_dev_attr_index,\n--\ndrivers/thunderbolt/stream.c=1219=static void tbstream_dev_item_release(struct config_item *item)\n--\ndrivers/thunderbolt/stream.c-1227-\ndrivers/thunderbolt/stream.c:1228:static struct configfs_item_operations tbstream_dev_item_ops = {\ndrivers/thunderbolt/stream.c-1229-\t.release = tbstream_dev_item_release,\n--\ndrivers/thunderbolt/stream.c=1391=tbstream_dev_drop_item(struct config_group *group, struct config_item *item)\n--\ndrivers/thunderbolt/stream.c-1404-\ndrivers/thunderbolt/stream.c:1405:static struct configfs_group_operations tbstream_dev_group_ops = {\ndrivers/thunderbolt/stream.c-1406-\t.make_group = tbstream_dev_make_group,\n--\ndrivers/thunderbolt/stream.c=1410=static void tbstream_item_release(struct config_item *item)\n--\ndrivers/thunderbolt/stream.c-1418-\ndrivers/thunderbolt/stream.c:1419:static struct configfs_item_operations tbstream_item_ops = {\ndrivers/thunderbolt/stream.c-1420-\t.release = tbstream_item_release,\n--\ndrivers/thunderbolt/stream.c=1430=tbstream_make_group(struct config_group *group, const char *name)\n--\ndrivers/thunderbolt/stream.c-1461-\ndrivers/thunderbolt/stream.c:1462:static struct configfs_group_operations tbstream_group_ops = {\ndrivers/thunderbolt/stream.c-1463-\t.make_group = tbstream_make_group,\n--\ndrivers/thunderbolt/stream.c=1648=static int __init tbstream_init(void)\n--\ndrivers/thunderbolt/stream.c-1665-\tconfig_group_init(\u0026tbstream_group);\ndrivers/thunderbolt/stream.c:1666:\tret = tb_configfs_register_group(\u0026tbstream_group);\ndrivers/thunderbolt/stream.c-1667-\tif (ret)\n--\ndrivers/thunderbolt/stream.c-1675-err_unregister_group:\ndrivers/thunderbolt/stream.c:1676:\ttb_configfs_unregister_group(\u0026tbstream_group);\ndrivers/thunderbolt/stream.c-1677-err_unregister_dir:\n--\ndrivers/thunderbolt/stream.c=1685=static void __exit tbstream_exit(void)\n--\ndrivers/thunderbolt/stream.c-1687-\ttb_unregister_service_driver(\u0026tbstream_driver);\ndrivers/thunderbolt/stream.c:1688:\ttb_configfs_unregister_group(\u0026tbstream_group);\ndrivers/thunderbolt/stream.c-1689-\ttb_unregister_property_dir(\"stream\", tbstream_dir);\n--\ndrivers/thunderbolt/tb.h=1559=static inline void tb_retimer_debugfs_remove(struct tb_retimer *rt) { }\n--\ndrivers/thunderbolt/tb.h-1562-#if IS_REACHABLE(CONFIG_CONFIGFS_FS)\ndrivers/thunderbolt/tb.h:1563:int tb_configfs_init(void);\ndrivers/thunderbolt/tb.h:1564:void tb_configfs_exit(void);\ndrivers/thunderbolt/tb.h-1565-#else\ndrivers/thunderbolt/tb.h:1566:static inline int tb_configfs_init(void) { return 0; }\ndrivers/thunderbolt/tb.h:1567:static inline void tb_configfs_exit(void) { }\ndrivers/thunderbolt/tb.h-1568-#endif\n"
}

gemini-3.1-pro-preview

null

null

							input: 40807
							output: 34
							thoughts: 72
						

**Delving into the `tbstream` Architecture**

Okay, so I'm looking into how `tbstream`, which I know is used for stream creation, interfaces with ConfigFS. It looks like `tbstream` is actually defined within `drivers/thunderbolt/stream.c`. Right, that makes sense. Now, I need to understand the connection between `tbstream` and the underlying services. Specifically, I'm thinking about the process of how groups and services are made when a stream is instantiated. I recall `tbstream_make_group` plays a role in constructing a group. Let me quickly examine `tbstream_make_group` to confirm if it, in fact, generates `tb_service` instances, or if the instantiation occurs elsewhere in the process. Time to dig in a bit deeper.

{
  "Expression": "tbstream_make_group",
  "PathPrefix": "drivers/thunderbolt/stream.c"
}

{
  "Output": "drivers/thunderbolt/stream.c=1429=static struct config_group *\ndrivers/thunderbolt/stream.c:1430:tbstream_make_group(struct config_group *group, const char *name)\ndrivers/thunderbolt/stream.c-1431-{\n--\ndrivers/thunderbolt/stream.c=1462=static struct configfs_group_operations tbstream_group_ops = {\ndrivers/thunderbolt/stream.c:1463:\t.make_group = tbstream_make_group,\ndrivers/thunderbolt/stream.c-1464-};\n"
}

gemini-3.1-pro-preview

null

null

							input: 41243
							output: 37
							thoughts: 12
						

Okay, let's dive into this. Here's my take on `tbstream_make_group`:

**Dissecting `tbstream_make_group`**

Alright, I'm going to dig into `tbstream_make_group`. Immediately, I'm thinking about its role within the larger picture – what is it supposed to *do*? Is this a function for constructing a new stream group object? Is it responsible for initial setup, memory allocation, or maybe just wrapping existing streams? Considering the naming convention, "make_group" seems to lean towards an instantiation or construction process. I'll need to figure out what parameters it expects. Understanding those parameters will be key to understanding the group's composition. What data structures are involved? Are there any dependencies? I'm anticipating elements like stream handles or descriptors, but I'll need to confirm that. I'll need to check for potential error conditions and return values. Are there specific error codes for failures during the group creation? Is there any graceful degradation in case of failure? Ultimately, I'll need to see how this function is intended to be used and in which context to have a full understanding of it.

{
  "File": "drivers/thunderbolt/stream.c",
  "FirstLine": 1429,
  "LineCount": 35
}

{
  "Contents": "1429:\tstatic struct config_group *\n1430:\ttbstream_make_group(struct config_group *group, const char *name)\n1431:\t{\n1432:\t\tstruct tbstream_group *sg;\n1433:\t\tstruct tbstream *stream;\n1434:\t\tint domain, index;\n1435:\t\tu64 route;\n1436:\t\n1437:\t\t/* Make sure the format is correct */\n1438:\t\tif (sscanf(name, \"%u-%llx.%u\", \u0026domain, \u0026route, \u0026index) != 3)\n1439:\t\t\treturn ERR_PTR(-EINVAL);\n1440:\t\n1441:\t\tsg = kzalloc_obj(*sg, GFP_KERNEL);\n1442:\t\tif (!sg)\n1443:\t\t\treturn ERR_PTR(-ENOMEM);\n1444:\t\n1445:\t\tmutex_init(\u0026sg-\u003elock);\n1446:\t\tINIT_LIST_HEAD(\u0026sg-\u003edev_list);\n1447:\t\n1448:\t\tguard(mutex)(\u0026tbstream_lock);\n1449:\t\tlist_for_each_entry(stream, \u0026tbstream_list, list) {\n1450:\t\t\ttbstream_get(stream);\n1451:\t\t\tif (sysfs_streq(name, dev_name(\u0026stream-\u003esvc-\u003edev))) {\n1452:\t\t\t\tsg-\u003estream = stream;\n1453:\t\t\t\tbreak;\n1454:\t\t\t}\n1455:\t\t\ttbstream_put(stream);\n1456:\t\t}\n1457:\t\n1458:\t\tconfig_group_init_type_name(\u0026sg-\u003egroup, name, \u0026tbstream_dev_group_type);\n1459:\t\treturn \u0026sg-\u003egroup;\n1460:\t}\n1461:\t\n1462:\tstatic struct configfs_group_operations tbstream_group_ops = {\n1463:\t\t.make_group = tbstream_make_group,\n"
}

gemini-3.1-pro-preview

null

null

							input: 42074
							output: 118
							thoughts: 621
						

**Thunderbolt Networking in QEMU: Unreachable Code Paths**

Okay, let's break this down. My initial assessment is that this patch targets Thunderbolt networking. I see it starts by looking up an existing `tbstream` by name, which is derived from the `tb_service` dev_name. Crucially, it doesn't *create* a `tb_service`. This means, from a userspace perspective, we can't instantiate a `tb_service` ourselves.

Without a `tb_service`, the vital `tbnet_probe` function is never invoked. And without `tbnet_probe`, the entire `tbnet` driver is completely inaccessible. Now, the kicker: QEMU, in its standard configuration, doesn't provide any Thunderbolt controller emulation. This means the Thunderbolt core will never find any controllers, never discover devices, and therefore, will never generate any `tb_service` devices. Consequently, `tbnet_probe` will *never* be called.

Therefore, this code in `drivers/net/thunderbolt/main.c` is utterly unreachable in a virtualized environment like GCE or QEMU.

Wait, is there *any* other route to this code? I'm wondering if a Thunderbolt device could be injected somehow? Unfortunately, there's no equivalent to `vhci` or `mac80211_hwsim` for Thunderbolt. The `test.c` driver is a KUnit test, and it doesn't expose a mock Thunderbolt controller to the system. This confirms it: `thunderbolt-net` simply cannot be fuzzed in QEMU.

Let's double-check if `USB4_NET` can be reached. The patch focuses on `tbnet_connect_failed` and `tbnet_connected_work`, both part of the `thunderbolt-net` driver. Since that driver fundamentally relies on Thunderbolt hardware, which is *not* emulated in QEMU, it's a dead end. I'm going to return `WorthFuzzing=false` here, based on the fact that Thunderbolt networking absolutely requires either physical hardware or a robust emulation layer, which QEMU doesn't have.

Let me just review the instructions. They explicitly say: "Return WorthFuzzing=false if the patch only contains code paths that are impossible to reach in virtualized environments... even when utilizing software-emulated hardware". This precisely fits Thunderbolt networking. There's no software-emulated Thunderbolt controller in QEMU.

Finally, just to be completely certain, let's verify if `USB4_NET` depends on `USB4` (the Thunderbolt core). Yes, `drivers/net/thunderbolt/Kconfig` confirms: `config USB4_NET... depends on USB4 && INET`. And since there is no Thunderbolt controller emulation in QEMU, the code remains unreachable.

So, I'm sticking with `WorthFuzzing=false`.

{
  "EnableConfigs": [],
  "FocusSymbols": [],
  "Reasoning": "The patch modifies the Thunderbolt networking driver (thunderbolt-net). This driver requires a Thunderbolt controller and XDomain connections to function. Since there is no software emulation for Thunderbolt controllers in standard QEMU (unlike USB with vhci or Wi-Fi with mac80211_hwsim), the driver cannot be probed and the modified code paths are impossible to reach in virtualized environments like GCE or QEMU.",
  "WorthFuzzing": false
}

{
  "EnableConfigs": null,
  "FocusSymbols": [],
  "Reasoning": "The patch modifies the Thunderbolt networking driver (thunderbolt-net). This driver requires a Thunderbolt controller and XDomain connections to function. Since there is no software emulation for Thunderbolt controllers in standard QEMU (unlike USB with vhci or Wi-Fi with mac80211_hwsim), the driver cannot be probed and the modified code paths are impossible to reach in virtualized environments like GCE or QEMU.",
  "WorthFuzzing": false
}

{
  "WorthFuzzing": false
}

null