From: Tariq Toukan <tariqt@nvidia.com>
To: Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Andrew Lunn <andrew+netdev@lunn.ch>,
"David S. Miller" <davem@davemloft.net>
Cc: Donald Hunter <donald.hunter@gmail.com>,
Jiri Pirko <jiri@resnulli.us>, Shuah Khan <shuah@kernel.org>,
<netdev@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
<linux-kselftest@vger.kernel.org>, Mark Bloch <mbloch@nvidia.com>,
Jiri Pirko <jiri@nvidia.com>, Cosmin Ratiu <cratiu@nvidia.com>,
Gal Pressman <gal@nvidia.com>,
Carolina Jubran <cjubran@nvidia.com>,
Tariq Toukan <tariqt@nvidia.com>
Subject: [PATCH net-next] devlink: Fix excessive stack usage in rate TC bandwidth parsing
Date: Tue, 22 Jul 2025 12:13:29 +0300 [thread overview]
Message-ID: <1753175609-330621-1-git-send-email-tariqt@nvidia.com> (raw)
From: Carolina Jubran <cjubran@nvidia.com>
The devlink_nl_rate_tc_bw_parse function uses a large stack array for
devlink attributes, which triggers a warning about excessive stack
usage:
net/devlink/rate.c: In function 'devlink_nl_rate_tc_bw_parse':
net/devlink/rate.c:382:1: error: the frame size of 1648 bytes is larger than 1536 bytes [-Werror=frame-larger-than=]
Introduce a separate attribute set specifically for rate TC bandwidth
parsing that only contains the two attributes actually used: index
and bandwidth. This reduces the stack array from DEVLINK_ATTR_MAX
entries to just 2 entries, solving the stack usage issue.
Update devlink selftest to use the new 'index' and 'bw' attribute names
consistent with the YAML spec.
Example usage with ynl with the new spec:
./tools/net/ynl/cli.py --spec Documentation/netlink/specs/devlink.yaml \
--do rate-set --json '{
"bus-name": "pci",
"dev-name": "0000:08:00.0",
"port-index": 1,
"rate-tc-bws": [
{"index": 0, "bw": 50},
{"index": 1, "bw": 50},
{"index": 2, "bw": 0},
{"index": 3, "bw": 0},
{"index": 4, "bw": 0},
{"index": 5, "bw": 0},
{"index": 6, "bw": 0},
{"index": 7, "bw": 0}
]
}'
./tools/net/ynl/cli.py --spec Documentation/netlink/specs/devlink.yaml \
--do rate-get --json '{
"bus-name": "pci",
"dev-name": "0000:08:00.0",
"port-index": 1
}'
output for rate-get:
{'bus-name': 'pci',
'dev-name': '0000:08:00.0',
'port-index': 1,
'rate-tc-bws': [{'bw': 50, 'index': 0},
{'bw': 50, 'index': 1},
{'bw': 0, 'index': 2},
{'bw': 0, 'index': 3},
{'bw': 0, 'index': 4},
{'bw': 0, 'index': 5},
{'bw': 0, 'index': 6},
{'bw': 0, 'index': 7}],
'rate-tx-max': 0,
'rate-tx-priority': 0,
'rate-tx-share': 0,
'rate-tx-weight': 0,
'rate-type': 'leaf'}
Fixes: 566e8f108fc7 ("devlink: Extend devlink rate API with traffic classes bandwidth management")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Closes: https://lore.kernel.org/netdev/20250708160652.1810573-1-arnd@kernel.org/
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202507171943.W7DJcs6Y-lkp@intel.com/
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Tested-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Tariq Toukan <tariqt@nvidia.com>
---
Documentation/netlink/specs/devlink.yaml | 26 ++++++++-----------
include/uapi/linux/devlink.h | 11 ++++++--
net/devlink/netlink_gen.c | 6 ++---
net/devlink/netlink_gen.h | 2 +-
net/devlink/rate.c | 20 +++++++-------
.../drivers/net/hw/devlink_rate_tc_bw.py | 16 ++++++------
6 files changed, 42 insertions(+), 39 deletions(-)
diff --git a/Documentation/netlink/specs/devlink.yaml b/Documentation/netlink/specs/devlink.yaml
index 1c4bb0cbe5f0..bb87111d5e16 100644
--- a/Documentation/netlink/specs/devlink.yaml
+++ b/Documentation/netlink/specs/devlink.yaml
@@ -853,18 +853,6 @@ attribute-sets:
type: nest
multi-attr: true
nested-attributes: dl-rate-tc-bws
- -
- name: rate-tc-index
- type: u8
- checks:
- max: rate-tc-index-max
- -
- name: rate-tc-bw
- type: u32
- doc: |
- Specifies the bandwidth share assigned to the Traffic Class.
- The bandwidth for the traffic class is determined
- in proportion to the sum of the shares of all configured classes.
-
name: dl-dev-stats
subset-of: devlink
@@ -1271,12 +1259,20 @@ attribute-sets:
type: flag
-
name: dl-rate-tc-bws
- subset-of: devlink
+ name-prefix: devlink-rate-tc-attr-
attributes:
-
- name: rate-tc-index
+ name: index
+ type: u8
+ checks:
+ max: rate-tc-index-max
-
- name: rate-tc-bw
+ name: bw
+ type: u32
+ doc: |
+ Specifies the bandwidth share assigned to the Traffic Class.
+ The bandwidth for the traffic class is determined
+ in proportion to the sum of the shares of all configured classes.
operations:
enum-model: directional
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index e72bcc239afd..9fcb25a0f447 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -635,8 +635,6 @@ enum devlink_attr {
DEVLINK_ATTR_REGION_DIRECT, /* flag */
DEVLINK_ATTR_RATE_TC_BWS, /* nested */
- DEVLINK_ATTR_RATE_TC_INDEX, /* u8 */
- DEVLINK_ATTR_RATE_TC_BW, /* u32 */
/* Add new attributes above here, update the spec in
* Documentation/netlink/specs/devlink.yaml and re-generate
@@ -647,6 +645,15 @@ enum devlink_attr {
DEVLINK_ATTR_MAX = __DEVLINK_ATTR_MAX - 1
};
+enum devlink_rate_tc_attr {
+ DEVLINK_RATE_TC_ATTR_UNSPEC,
+ DEVLINK_RATE_TC_ATTR_INDEX, /* u8 */
+ DEVLINK_RATE_TC_ATTR_BW, /* u32 */
+
+ __DEVLINK_RATE_TC_ATTR_MAX,
+ DEVLINK_RATE_TC_ATTR_MAX = __DEVLINK_RATE_TC_ATTR_MAX - 1
+};
+
/* Mapping between internal resource described by the field and system
* structure
*/
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index c50436433c18..d97c326a9045 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -45,9 +45,9 @@ const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_
[DEVLINK_PORT_FN_ATTR_CAPS] = NLA_POLICY_BITFIELD32(15),
};
-const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_ATTR_RATE_TC_BW + 1] = {
- [DEVLINK_ATTR_RATE_TC_INDEX] = NLA_POLICY_MAX(NLA_U8, DEVLINK_RATE_TC_INDEX_MAX),
- [DEVLINK_ATTR_RATE_TC_BW] = { .type = NLA_U32, },
+const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_RATE_TC_ATTR_BW + 1] = {
+ [DEVLINK_RATE_TC_ATTR_INDEX] = NLA_POLICY_MAX(NLA_U8, DEVLINK_RATE_TC_INDEX_MAX),
+ [DEVLINK_RATE_TC_ATTR_BW] = { .type = NLA_U32, },
};
const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1] = {
diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
index fb733b5d4ff1..09cc6f264ccf 100644
--- a/net/devlink/netlink_gen.h
+++ b/net/devlink/netlink_gen.h
@@ -13,7 +13,7 @@
/* Common nested types */
extern const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_CAPS + 1];
-extern const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_ATTR_RATE_TC_BW + 1];
+extern const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_RATE_TC_ATTR_BW + 1];
extern const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];
/* Ops table for devlink */
diff --git a/net/devlink/rate.c b/net/devlink/rate.c
index d39300a9b3d4..110b3fa8a0b1 100644
--- a/net/devlink/rate.c
+++ b/net/devlink/rate.c
@@ -90,8 +90,8 @@ static int devlink_rate_put_tc_bws(struct sk_buff *msg, u32 *tc_bw)
if (!nla_tc_bw)
return -EMSGSIZE;
- if (nla_put_u8(msg, DEVLINK_ATTR_RATE_TC_INDEX, i) ||
- nla_put_u32(msg, DEVLINK_ATTR_RATE_TC_BW, tc_bw[i]))
+ if (nla_put_u8(msg, DEVLINK_RATE_TC_ATTR_INDEX, i) ||
+ nla_put_u32(msg, DEVLINK_RATE_TC_ATTR_BW, tc_bw[i]))
goto nla_put_failure;
nla_nest_end(msg, nla_tc_bw);
@@ -346,26 +346,26 @@ static int devlink_nl_rate_tc_bw_parse(struct nlattr *parent_nest, u32 *tc_bw,
unsigned long *bitmap,
struct netlink_ext_ack *extack)
{
- struct nlattr *tb[DEVLINK_ATTR_MAX + 1];
+ struct nlattr *tb[DEVLINK_RATE_TC_ATTR_MAX + 1];
u8 tc_index;
int err;
- err = nla_parse_nested(tb, DEVLINK_ATTR_MAX, parent_nest,
+ err = nla_parse_nested(tb, DEVLINK_RATE_TC_ATTR_MAX, parent_nest,
devlink_dl_rate_tc_bws_nl_policy, extack);
if (err)
return err;
- if (!tb[DEVLINK_ATTR_RATE_TC_INDEX]) {
+ if (!tb[DEVLINK_RATE_TC_ATTR_INDEX]) {
NL_SET_ERR_ATTR_MISS(extack, parent_nest,
- DEVLINK_ATTR_RATE_TC_INDEX);
+ DEVLINK_RATE_TC_ATTR_INDEX);
return -EINVAL;
}
- tc_index = nla_get_u8(tb[DEVLINK_ATTR_RATE_TC_INDEX]);
+ tc_index = nla_get_u8(tb[DEVLINK_RATE_TC_ATTR_INDEX]);
- if (!tb[DEVLINK_ATTR_RATE_TC_BW]) {
+ if (!tb[DEVLINK_RATE_TC_ATTR_BW]) {
NL_SET_ERR_ATTR_MISS(extack, parent_nest,
- DEVLINK_ATTR_RATE_TC_BW);
+ DEVLINK_RATE_TC_ATTR_BW);
return -EINVAL;
}
@@ -376,7 +376,7 @@ static int devlink_nl_rate_tc_bw_parse(struct nlattr *parent_nest, u32 *tc_bw,
return -EINVAL;
}
- tc_bw[tc_index] = nla_get_u32(tb[DEVLINK_ATTR_RATE_TC_BW]);
+ tc_bw[tc_index] = nla_get_u32(tb[DEVLINK_RATE_TC_ATTR_BW]);
return 0;
}
diff --git a/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py b/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py
index 820d8a03becc..835c357919a8 100755
--- a/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py
+++ b/tools/testing/selftests/drivers/net/hw/devlink_rate_tc_bw.py
@@ -208,14 +208,14 @@ def setup_devlink_rate(cfg):
"port-index": port_index,
"rate-tx-max": 125000000,
"rate-tc-bws": [
- {"rate-tc-index": 0, "rate-tc-bw": 0},
- {"rate-tc-index": 1, "rate-tc-bw": 0},
- {"rate-tc-index": 2, "rate-tc-bw": 0},
- {"rate-tc-index": 3, "rate-tc-bw": 20},
- {"rate-tc-index": 4, "rate-tc-bw": 80},
- {"rate-tc-index": 5, "rate-tc-bw": 0},
- {"rate-tc-index": 6, "rate-tc-bw": 0},
- {"rate-tc-index": 7, "rate-tc-bw": 0},
+ {"index": 0, "bw": 0},
+ {"index": 1, "bw": 0},
+ {"index": 2, "bw": 0},
+ {"index": 3, "bw": 20},
+ {"index": 4, "bw": 80},
+ {"index": 5, "bw": 0},
+ {"index": 6, "bw": 0},
+ {"index": 7, "bw": 0},
]
})
except NlError as exc:
base-commit: 3fc894728fb3a0d9282e81247b68c07468fe2985
--
2.31.1
next reply other threads:[~2025-07-22 9:14 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-22 9:13 Tariq Toukan [this message]
2025-07-22 9:22 ` [PATCH net-next] devlink: Fix excessive stack usage in rate TC bandwidth parsing Jiri Pirko
2025-07-23 2:08 ` Jakub Kicinski
2025-07-24 2:00 ` patchwork-bot+netdevbpf
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