[PATCH net-next v3 0/2] netdevgenl: Add an xsk attribute to queues

[PATCH net-next v3 0/2] netdevgenl: Add an xsk attribute to queues

[Joe Damato]

Greetings:

Welcome to v3. No functional changes, see changelog below.

This is an attempt to followup on something Jakub asked me about [1],
adding an xsk attribute to queues and more clearly documenting which
queues are linked to NAPIs...

After the RFC [2], Jakub suggested creating an empty nest for queues
which have a pool, so I've adjusted this version to work that way.

The nest can be extended in the future to express attributes about XSK
as needed. Queues which are not used for AF_XDP do not have the xsk
attribute present.

I've run the included test on:
  - my mlx5 machine (via NETIF=)
  - without setting NETIF

And the test seems to pass in both cases.

Thanks,
Joe

[1]: https://lore.kernel.org/netdev/20250113143109.60afa59a@kernel.org/
[2]: https://lore.kernel.org/netdev/20250129172431.65773-1-jdamato@fastly.com/

v3:
  - Change comment format in patch 2 to avoid kdoc warnings. No other
    changes.

v2: https://lore.kernel.org/all/20250203185828.19334-1-jdamato@fastly.com/
  - Switched from RFC to actual submission now that net-next is open
  - Adjusted patch 1 to include an empty nest as suggested by Jakub
  - Adjusted patch 2 to update the test based on changes to patch 1, and
    to incorporate some Python feedback from Jakub :)

rfc: https://lore.kernel.org/netdev/20250129172431.65773-1-jdamato@fastly.com/

Joe Damato (2):
  netdev-genl: Add an XSK attribute to queues
  selftests: drv-net: Test queue xsk attribute

 Documentation/netlink/specs/netdev.yaml       | 13 ++-
 include/uapi/linux/netdev.h                   |  6 ++
 net/core/netdev-genl.c                        | 11 +++
 tools/include/uapi/linux/netdev.h             |  6 ++
 .../testing/selftests/drivers/net/.gitignore  |  2 +
 tools/testing/selftests/drivers/net/Makefile  |  3 +
 tools/testing/selftests/drivers/net/queues.py | 35 +++++++-
 .../selftests/drivers/net/xdp_helper.c        | 89 +++++++++++++++++++
 8 files changed, 162 insertions(+), 3 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/.gitignore
 create mode 100644 tools/testing/selftests/drivers/net/xdp_helper.c


base-commit: c2933b2befe25309f4c5cfbea0ca80909735fd76
-- 
2.43.0

[PATCH net-next v3 1/2] netdev-genl: Add an XSK attribute to queues

[Joe Damato]

Expose a new per-queue nest attribute, xsk, which will be present for
queues that are being used for AF_XDP. If the queue is not being used for
AF_XDP, the nest will not be present.

In the future, this attribute can be extended to include more data about
XSK as it is needed.

Signed-off-by: Joe Damato <jdamato@fastly.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
---
 v2:
   - Patch adjusted to include an attribute, xsk, which is an empty nest
     and exposed for queues which have a pool.

 Documentation/netlink/specs/netdev.yaml | 13 ++++++++++++-
 include/uapi/linux/netdev.h             |  6 ++++++
 net/core/netdev-genl.c                  | 11 +++++++++++
 tools/include/uapi/linux/netdev.h       |  6 ++++++
 4 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/Documentation/netlink/specs/netdev.yaml b/Documentation/netlink/specs/netdev.yaml
index cbb544bd6c84..4c3eda5ba754 100644
--- a/Documentation/netlink/specs/netdev.yaml
+++ b/Documentation/netlink/specs/netdev.yaml
@@ -268,6 +268,9 @@ attribute-sets:
         doc: The timeout, in nanoseconds, of how long to suspend irq
              processing, if event polling finds events
         type: uint
+  -
+    name: xsk-info
+    attributes: []
   -
     name: queue
     attributes:
@@ -286,6 +289,9 @@ attribute-sets:
       -
         name: type
         doc: Queue type as rx, tx. Each queue type defines a separate ID space.
+             XDP TX queues allocated in the kernel are not linked to NAPIs and
+             thus not listed. AF_XDP queues will have more information set in
+             the xsk attribute.
         type: u32
         enum: queue-type
       -
@@ -296,7 +302,11 @@ attribute-sets:
         name: dmabuf
         doc: ID of the dmabuf attached to this queue, if any.
         type: u32
-
+      -
+        name: xsk
+        doc: XSK information for this queue, if any.
+        type: nest
+        nested-attributes: xsk-info
   -
     name: qstats
     doc: |
@@ -637,6 +647,7 @@ operations:
             - napi-id
             - ifindex
             - dmabuf
+            - xsk
       dump:
         request:
           attributes:
diff --git a/include/uapi/linux/netdev.h b/include/uapi/linux/netdev.h
index e4be227d3ad6..46bdb0b67a39 100644
--- a/include/uapi/linux/netdev.h
+++ b/include/uapi/linux/netdev.h
@@ -130,12 +130,18 @@ enum {
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
 };
 
+enum {
+	__NETDEV_A_XSK_INFO_MAX,
+	NETDEV_A_XSK_INFO_MAX = (__NETDEV_A_XSK_INFO_MAX - 1)
+};
+
 enum {
 	NETDEV_A_QUEUE_ID = 1,
 	NETDEV_A_QUEUE_IFINDEX,
 	NETDEV_A_QUEUE_TYPE,
 	NETDEV_A_QUEUE_NAPI_ID,
 	NETDEV_A_QUEUE_DMABUF,
+	NETDEV_A_QUEUE_XSK,
 
 	__NETDEV_A_QUEUE_MAX,
 	NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
diff --git a/net/core/netdev-genl.c b/net/core/netdev-genl.c
index 715f85c6b62e..efaccfb6438e 100644
--- a/net/core/netdev-genl.c
+++ b/net/core/netdev-genl.c
@@ -371,6 +371,7 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
 	struct net_devmem_dmabuf_binding *binding;
 	struct netdev_rx_queue *rxq;
 	struct netdev_queue *txq;
+	struct nlattr *nest;
 	void *hdr;
 
 	hdr = genlmsg_iput(rsp, info);
@@ -394,12 +395,22 @@ netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
 		    nla_put_u32(rsp, NETDEV_A_QUEUE_DMABUF, binding->id))
 			goto nla_put_failure;
 
+		if (rxq->pool) {
+			nest = nla_nest_start(rsp, NETDEV_A_QUEUE_XSK);
+			nla_nest_end(rsp, nest);
+		}
+
 		break;
 	case NETDEV_QUEUE_TYPE_TX:
 		txq = netdev_get_tx_queue(netdev, q_idx);
 		if (txq->napi && nla_put_u32(rsp, NETDEV_A_QUEUE_NAPI_ID,
 					     txq->napi->napi_id))
 			goto nla_put_failure;
+
+		if (txq->pool) {
+			nest = nla_nest_start(rsp, NETDEV_A_QUEUE_XSK);
+			nla_nest_end(rsp, nest);
+		}
 	}
 
 	genlmsg_end(rsp, hdr);
diff --git a/tools/include/uapi/linux/netdev.h b/tools/include/uapi/linux/netdev.h
index e4be227d3ad6..46bdb0b67a39 100644
--- a/tools/include/uapi/linux/netdev.h
+++ b/tools/include/uapi/linux/netdev.h
@@ -130,12 +130,18 @@ enum {
 	NETDEV_A_NAPI_MAX = (__NETDEV_A_NAPI_MAX - 1)
 };
 
+enum {
+	__NETDEV_A_XSK_INFO_MAX,
+	NETDEV_A_XSK_INFO_MAX = (__NETDEV_A_XSK_INFO_MAX - 1)
+};
+
 enum {
 	NETDEV_A_QUEUE_ID = 1,
 	NETDEV_A_QUEUE_IFINDEX,
 	NETDEV_A_QUEUE_TYPE,
 	NETDEV_A_QUEUE_NAPI_ID,
 	NETDEV_A_QUEUE_DMABUF,
+	NETDEV_A_QUEUE_XSK,
 
 	__NETDEV_A_QUEUE_MAX,
 	NETDEV_A_QUEUE_MAX = (__NETDEV_A_QUEUE_MAX - 1)
-- 
2.43.0

[PATCH net-next v3 2/2] selftests: drv-net: Test queue xsk attribute

[Joe Damato]

Test that queues which are used for AF_XDP have the xsk nest attribute.
The attribute is currently empty, but its existence means the AF_XDP is
being used for the queue.

Signed-off-by: Joe Damato <jdamato@fastly.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
---
 v3:
   - Change comment style of helper C program to avoid kdoc warnings as
     suggested by Jakub. No other changes.

 v2:
   - Updated the Python test after changes to patch 1 which expose an
     empty nest
   - Updated Python test with general Python coding feedback

 .../testing/selftests/drivers/net/.gitignore  |  2 +
 tools/testing/selftests/drivers/net/Makefile  |  3 +
 tools/testing/selftests/drivers/net/queues.py | 35 +++++++-
 .../selftests/drivers/net/xdp_helper.c        | 89 +++++++++++++++++++
 4 files changed, 127 insertions(+), 2 deletions(-)
 create mode 100644 tools/testing/selftests/drivers/net/.gitignore
 create mode 100644 tools/testing/selftests/drivers/net/xdp_helper.c

diff --git a/tools/testing/selftests/drivers/net/.gitignore b/tools/testing/selftests/drivers/net/.gitignore
new file mode 100644
index 000000000000..ec746f374e85
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/.gitignore
@@ -0,0 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
+xdp_helper
diff --git a/tools/testing/selftests/drivers/net/Makefile b/tools/testing/selftests/drivers/net/Makefile
index 137470bdee0c..f6ec08680f48 100644
--- a/tools/testing/selftests/drivers/net/Makefile
+++ b/tools/testing/selftests/drivers/net/Makefile
@@ -1,10 +1,13 @@
 # SPDX-License-Identifier: GPL-2.0
+CFLAGS += $(KHDR_INCLUDES)
 
 TEST_INCLUDES := $(wildcard lib/py/*.py) \
 		 $(wildcard lib/sh/*.sh) \
 		 ../../net/net_helper.sh \
 		 ../../net/lib.sh \
 
+TEST_GEN_PROGS := xdp_helper
+
 TEST_PROGS := \
 	netcons_basic.sh \
 	netcons_overflow.sh \
diff --git a/tools/testing/selftests/drivers/net/queues.py b/tools/testing/selftests/drivers/net/queues.py
index 38303da957ee..55c2b296ad3c 100755
--- a/tools/testing/selftests/drivers/net/queues.py
+++ b/tools/testing/selftests/drivers/net/queues.py
@@ -8,7 +8,10 @@ from lib.py import NetDrvEnv
 from lib.py import cmd, defer, ip
 import errno
 import glob
-
+import os
+import socket
+import struct
+import subprocess
 
 def sys_get_queues(ifname, qtype='rx') -> int:
     folders = glob.glob(f'/sys/class/net/{ifname}/queues/{qtype}-*')
@@ -21,6 +24,34 @@ def nl_get_queues(cfg, nl, qtype='rx'):
         return len([q for q in queues if q['type'] == qtype])
     return None
 
+def check_xdp(cfg, nl, xdp_queue_id=0) -> None:
+    test_dir = os.path.dirname(os.path.realpath(__file__))
+    xdp = subprocess.Popen([f"{test_dir}/xdp_helper", f"{cfg.ifindex}", f"{xdp_queue_id}"],
+                           stdin=subprocess.PIPE, stdout=subprocess.PIPE, bufsize=1,
+                           text=True)
+    defer(xdp.kill)
+
+    stdout, stderr = xdp.communicate(timeout=10)
+    rx = tx = False
+
+    queues = nl.queue_get({'ifindex': cfg.ifindex}, dump=True)
+    if not queues:
+        raise KsftSkipEx("Netlink reports no queues")
+
+    for q in queues:
+        if q['id'] == 0:
+            if q['type'] == 'rx':
+                rx = True
+            if q['type'] == 'tx':
+                tx = True
+
+            ksft_eq(q['xsk'], {})
+        else:
+            if 'xsk' in q:
+                _fail("Check failed: xsk attribute set.")
+
+    ksft_eq(rx, True)
+    ksft_eq(tx, True)
 
 def get_queues(cfg, nl) -> None:
     snl = NetdevFamily(recv_size=4096)
@@ -81,7 +112,7 @@ def check_down(cfg, nl) -> None:
 
 def main() -> None:
     with NetDrvEnv(__file__, queue_count=100) as cfg:
-        ksft_run([get_queues, addremove_queues, check_down], args=(cfg, NetdevFamily()))
+        ksft_run([get_queues, addremove_queues, check_down, check_xdp], args=(cfg, NetdevFamily()))
     ksft_exit()
 
 
diff --git a/tools/testing/selftests/drivers/net/xdp_helper.c b/tools/testing/selftests/drivers/net/xdp_helper.c
new file mode 100644
index 000000000000..b04d4e0ea30a
--- /dev/null
+++ b/tools/testing/selftests/drivers/net/xdp_helper.c
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <sys/mman.h>
+#include <sys/socket.h>
+#include <linux/if_xdp.h>
+#include <linux/if_link.h>
+#include <net/if.h>
+#include <inttypes.h>
+
+#define UMEM_SZ (1U << 16)
+#define NUM_DESC (UMEM_SZ / 2048)
+
+/* this is a simple helper program that creates an XDP socket and does the
+ * minimum necessary to get bind() to succeed.
+ *
+ * this test program is not intended to actually process packets, but could be
+ * extended in the future if that is actually needed.
+ *
+ * it is used by queues.py to ensure the xsk netlinux attribute is set
+ * correctly.
+ */
+int main(int argc, char **argv)
+{
+	struct xdp_umem_reg umem_reg = { 0 };
+	struct sockaddr_xdp sxdp = { 0 };
+	int num_desc = NUM_DESC;
+	void *umem_area;
+	int ifindex;
+	int sock_fd;
+	int queue;
+	char byte;
+
+	if (argc != 3) {
+		fprintf(stderr, "Usage: %s ifindex queue_id", argv[0]);
+		return 1;
+	}
+
+	sock_fd = socket(AF_XDP, SOCK_RAW, 0);
+	if (sock_fd < 0) {
+		perror("socket creation failed");
+		return 1;
+	}
+
+	ifindex = atoi(argv[1]);
+	queue = atoi(argv[2]);
+
+	umem_area = mmap(NULL, UMEM_SZ, PROT_READ | PROT_WRITE, MAP_PRIVATE |
+			MAP_ANONYMOUS, -1, 0);
+	if (umem_area == MAP_FAILED)
+		return -1;
+
+	umem_reg.addr = (uintptr_t)umem_area;
+	umem_reg.len = UMEM_SZ;
+	umem_reg.chunk_size = 2048;
+	umem_reg.headroom = 0;
+
+	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_REG, &umem_reg,
+		   sizeof(umem_reg));
+	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_FILL_RING, &num_desc,
+		   sizeof(num_desc));
+	setsockopt(sock_fd, SOL_XDP, XDP_UMEM_COMPLETION_RING, &num_desc,
+		   sizeof(num_desc));
+	setsockopt(sock_fd, SOL_XDP, XDP_RX_RING, &num_desc, sizeof(num_desc));
+
+	sxdp.sxdp_family = AF_XDP;
+	sxdp.sxdp_ifindex = ifindex;
+	sxdp.sxdp_queue_id = queue;
+	sxdp.sxdp_flags = 0;
+
+	if (bind(sock_fd, (struct sockaddr *)&sxdp, sizeof(sxdp)) != 0) {
+		perror("bind failed");
+		close(sock_fd);
+		return 1;
+	}
+
+	/* give the parent program some data when the socket is ready*/
+	fprintf(stdout, "%d\n", sock_fd);
+
+	/* parent program will write a byte to stdin when its ready for this
+	 * helper to exit
+	 */
+	read(STDIN_FILENO, &byte, 1);
+
+	close(sock_fd);
+	return 0;
+}
-- 
2.43.0

Re: [PATCH net-next v3 1/2] netdev-genl: Add an XSK attribute to queues

[Jakub Kicinski]

On Tue,  4 Feb 2025 19:10:47 +0000 Joe Damato wrote:
> +		if (rxq->pool) {
> +			nest = nla_nest_start(rsp, NETDEV_A_QUEUE_XSK);
> +			nla_nest_end(rsp, nest);
> +		}

nla_nest_start() can fail, you gotta nul-check the return value.
You could possibly add an nla_put_empty_nest() helper in netlink.h
to make this less awkward? I think the iouring guys had the same bug

Re: [PATCH net-next v3 1/2] netdev-genl: Add an XSK attribute to queues

[Joe Damato]

On Thu, Feb 06, 2025 at 04:57:46PM -0800, Jakub Kicinski wrote:
> On Tue,  4 Feb 2025 19:10:47 +0000 Joe Damato wrote:
> > +		if (rxq->pool) {
> > +			nest = nla_nest_start(rsp, NETDEV_A_QUEUE_XSK);
> > +			nla_nest_end(rsp, nest);
> > +		}
> 
> nla_nest_start() can fail, you gotta nul-check the return value.
> You could possibly add an nla_put_empty_nest() helper in netlink.h
> to make this less awkward? I think the iouring guys had the same bug

Ah, right.

I'll see what a helper looks like. Feels like maybe overkill?

Thanks for the review.

Re: [PATCH net-next v3 1/2] netdev-genl: Add an XSK attribute to queues

[Jakub Kicinski]

On Thu, 6 Feb 2025 17:31:47 -0800 Joe Damato wrote:
> > nla_nest_start() can fail, you gotta nul-check the return value.
> > You could possibly add an nla_put_empty_nest() helper in netlink.h
> > to make this less awkward? I think the iouring guys had the same bug  
> 
> Ah, right.
> 
> I'll see what a helper looks like. Feels like maybe overkill?

Yeah, not sure either. Technically nla_nest_end() isn't required here,
but that's not very obvious to a casual reader. So a helper that hides
that fact could be useful:

static inline int nla_put_empty_nest(struct sk_buff *skb, int attrtype)
{
	return nla_nest_start(skb, attrtype) ? 0 : -EMSGSIZE;
}

But totally unsure whether it's worthwhile. Just don't want for someone
to suggest this on v4 and make you respin once again.

Re: [PATCH net-next v3 1/2] netdev-genl: Add an XSK attribute to queues

[Joe Damato]

On Thu, Feb 06, 2025 at 05:41:38PM -0800, Jakub Kicinski wrote:
> On Thu, 6 Feb 2025 17:31:47 -0800 Joe Damato wrote:
> > > nla_nest_start() can fail, you gotta nul-check the return value.
> > > You could possibly add an nla_put_empty_nest() helper in netlink.h
> > > to make this less awkward? I think the iouring guys had the same bug  
> > 
> > Ah, right.
> > 
> > I'll see what a helper looks like. Feels like maybe overkill?
> 
> Yeah, not sure either. Technically nla_nest_end() isn't required here,
> but that's not very obvious to a casual reader. So a helper that hides
> that fact could be useful:
> 
> static inline int nla_put_empty_nest(struct sk_buff *skb, int attrtype)
> {
> 	return nla_nest_start(skb, attrtype) ? 0 : -EMSGSIZE;
> }

Yea after reading the code it makes sense that nla_nest_end is not
needed. I wrote a small thing similar to what you proposed above,
but yours is more succinct.

I'll go with that and see how it looks.

> But totally unsure whether it's worthwhile. Just don't want for someone
> to suggest this on v4 and make you respin once again.

No worries; respinning is not the end of the world.

Re: [PATCH net-next v3 1/2] netdev-genl: Add an XSK attribute to queues

[kernel test robot]

Hi Joe,

kernel test robot noticed the following build errors:

[auto build test ERROR on c2933b2befe25309f4c5cfbea0ca80909735fd76]

url:    https://github.com/intel-lab-lkp/linux/commits/Joe-Damato/netdev-genl-Add-an-XSK-attribute-to-queues/20250205-031236
base:   c2933b2befe25309f4c5cfbea0ca80909735fd76
patch link:    https://lore.kernel.org/r/20250204191108.161046-2-jdamato%40fastly.com
patch subject: [PATCH net-next v3 1/2] netdev-genl: Add an XSK attribute to queues
config: arm-defconfig (https://download.01.org/0day-ci/archive/20250207/202502071452.B85Lw7aV-lkp@intel.com/config)
compiler: clang version 21.0.0git (https://github.com/llvm/llvm-project ee3bccab34f57387bdf33853cdd5f214fef349a2)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20250207/202502071452.B85Lw7aV-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202502071452.B85Lw7aV-lkp@intel.com/

All errors (new ones prefixed by >>):

>> net/core/netdev-genl.c:398:12: error: no member named 'pool' in 'struct netdev_rx_queue'
     398 |                 if (rxq->pool) {
         |                     ~~~  ^
>> net/core/netdev-genl.c:410:12: error: no member named 'pool' in 'struct netdev_queue'
     410 |                 if (txq->pool) {
         |                     ~~~  ^
   2 errors generated.


vim +398 net/core/netdev-genl.c

   366	
   367	static int
   368	netdev_nl_queue_fill_one(struct sk_buff *rsp, struct net_device *netdev,
   369				 u32 q_idx, u32 q_type, const struct genl_info *info)
   370	{
   371		struct net_devmem_dmabuf_binding *binding;
   372		struct netdev_rx_queue *rxq;
   373		struct netdev_queue *txq;
   374		struct nlattr *nest;
   375		void *hdr;
   376	
   377		hdr = genlmsg_iput(rsp, info);
   378		if (!hdr)
   379			return -EMSGSIZE;
   380	
   381		if (nla_put_u32(rsp, NETDEV_A_QUEUE_ID, q_idx) ||
   382		    nla_put_u32(rsp, NETDEV_A_QUEUE_TYPE, q_type) ||
   383		    nla_put_u32(rsp, NETDEV_A_QUEUE_IFINDEX, netdev->ifindex))
   384			goto nla_put_failure;
   385	
   386		switch (q_type) {
   387		case NETDEV_QUEUE_TYPE_RX:
   388			rxq = __netif_get_rx_queue(netdev, q_idx);
   389			if (rxq->napi && nla_put_u32(rsp, NETDEV_A_QUEUE_NAPI_ID,
   390						     rxq->napi->napi_id))
   391				goto nla_put_failure;
   392	
   393			binding = rxq->mp_params.mp_priv;
   394			if (binding &&
   395			    nla_put_u32(rsp, NETDEV_A_QUEUE_DMABUF, binding->id))
   396				goto nla_put_failure;
   397	
 > 398			if (rxq->pool) {
   399				nest = nla_nest_start(rsp, NETDEV_A_QUEUE_XSK);
   400				nla_nest_end(rsp, nest);
   401			}
   402	
   403			break;
   404		case NETDEV_QUEUE_TYPE_TX:
   405			txq = netdev_get_tx_queue(netdev, q_idx);
   406			if (txq->napi && nla_put_u32(rsp, NETDEV_A_QUEUE_NAPI_ID,
   407						     txq->napi->napi_id))
   408				goto nla_put_failure;
   409	
 > 410			if (txq->pool) {
   411				nest = nla_nest_start(rsp, NETDEV_A_QUEUE_XSK);
   412				nla_nest_end(rsp, nest);
   413			}
   414		}
   415	
   416		genlmsg_end(rsp, hdr);
   417	
   418		return 0;
   419	
   420	nla_put_failure:
   421		genlmsg_cancel(rsp, hdr);
   422		return -EMSGSIZE;
   423	}
   424	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki