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Kees Cook 151e13ece8 net: ethtool: Adjust exactly ETH_GSTRING_LEN-long stats to use memcpy
Many drivers populate the stats buffer using C-String based APIs (e.g.
ethtool_sprintf() and ethtool_puts()), usually when building up the
list of stats individually (i.e. with a for() loop). This, however,
requires that the source strings be populated in such a way as to have
a terminating NUL byte in the source.

Other drivers populate the stats buffer directly using one big memcpy()
of an entire array of strings. No NUL termination is needed here, as the
bytes are being directly passed through. Yet others will build up the
stats buffer individually, but also use memcpy(). This, too, does not
need NUL termination of the source strings.

However, there are cases where the strings that populate the
source stats strings are exactly ETH_GSTRING_LEN long, and GCC
15's -Wunterminated-string-initialization option complains that the
trailing NUL byte has been truncated. This situation is fine only if the
driver is using the memcpy() approach. If the C-String APIs are used,
the destination string name will have its final byte truncated by the
required trailing NUL byte applied by the C-string API.

For drivers that are already using memcpy() but have initializers that
truncate the NUL terminator, mark their source strings as __nonstring to
silence the GCC warnings.

For drivers that have initializers that truncate the NUL terminator and
are using the C-String APIs, switch to memcpy() to avoid destination
string truncation and mark their source strings as __nonstring to silence
the GCC warnings. (Also introduce ethtool_cpy() as a helper to make this
an easy replacement).

Specifically the following warnings were investigated and addressed:

../drivers/net/ethernet/chelsio/cxgb/cxgb2.c:364:9: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
  364 |         "TxFramesAbortedDueToXSCollisions",
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/net/ethernet/freescale/enetc/enetc_ethtool.c:165:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
  165 |         { ENETC_PM_R1523X(0),   "MAC rx 1523 to max-octet packets" },
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/net/ethernet/freescale/enetc/enetc_ethtool.c:190:33: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
  190 |         { ENETC_PM_T1523X(0),   "MAC tx 1523 to max-octet packets" },
      |                                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/net/ethernet/google/gve/gve_ethtool.c:76:9: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
   76 |         "adminq_dcfg_device_resources_cnt", "adminq_set_driver_parameter_cnt",
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c:117:53: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
  117 |         STMMAC_STAT(ptp_rx_msg_type_pdelay_follow_up),
      |                                                     ^
../drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c:46:12: note: in definition of macro 'STMMAC_STAT'
   46 |         { #m, sizeof_field(struct stmmac_extra_stats, m),       \
      |            ^
../drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c:328:24: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
  328 |                 .str = "a_mac_control_frames_transmitted",
      |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
../drivers/net/ethernet/mellanox/mlxsw/spectrum_ethtool.c:340:24: warning: initializer-string for array of 'char' truncates NUL terminator but destination lacks 'nonstring' attribute (33 chars into 32 available) [-Wunterminated-string-initialization]
  340 |                 .str = "a_pause_mac_ctrl_frames_received",
      |                        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Signed-off-by: Kees Cook <kees@kernel.org>
Reviewed-by: Petr Machata <petrm@nvidia.com> # for mlxsw
Reviewed-by: Harshitha Ramamurthy <hramamurthy@google.com>
Link: https://patch.msgid.link/20250416010210.work.904-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-17 18:53:52 -07:00
arch Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
block treewide: Switch/rename to timer_delete[_sync]() 2025-04-05 10:30:12 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: ahash - Disable request chaining 2025-04-12 09:33:09 +08:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
drivers net: ethtool: Adjust exactly ETH_GSTRING_LEN-long stats to use memcpy 2025-04-17 18:53:52 -07:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
include net: ethtool: Adjust exactly ETH_GSTRING_LEN-long stats to use memcpy 2025-04-17 18:53:52 -07:00
init Miscellaneous scheduler fixes/updates: 2025-04-06 10:44:58 -07:00
io_uring io_uring/kbuf: reject zero sized provided buffers 2025-04-07 07:51:23 -06:00
ipc treewide: const qualify ctl_tables where applicable 2025-01-28 13:48:37 +01:00
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
lib 31 hotfixes. 9 are cc:stable and the remainder address post-6.15 issues 2025-04-16 20:07:32 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
rust Kbuild updates for v6.15 2025-04-05 15:46:50 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
scripts net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
security net: Retire DCCP socket. 2025-04-11 18:58:10 -07:00
sound ASoC: Fixes for v6.15 2025-04-11 15:51:19 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
usr kbuild: hdrcheck: fix cross build with clang 2025-03-05 04:06:45 +09:00
virt ARM: 2025-04-08 13:47:55 -07:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.clippy.toml rust: give Clippy the minimum supported Rust version 2025-01-10 00:17:25 +01:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: Create intermediate vmlinux build with relocations preserved 2025-03-17 00:29:50 +09:00
.mailmap sound fixes for 6.15-rc3 2025-04-17 10:14:51 -07:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS Including fixes from netfilter. 2025-04-04 09:15:35 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2025-04-17 12:26:50 -07:00
Makefile Linux 6.15-rc2 2025-04-13 11:54:49 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.