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authorLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
committerLibravatar Linus Torvalds <torvalds@linux-foundation.org>2023-02-21 18:24:12 -0800
commit5b7c4cabbb65f5c469464da6c5f614cbd7f730f2 (patch)
treecc5c2d0a898769fd59549594fedb3ee6f84e59a0 /Documentation/dev-tools/kselftest.rst
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Merge tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-nextgrafted
Pull networking updates from Jakub Kicinski: "Core: - Add dedicated kmem_cache for typical/small skb->head, avoid having to access struct page at kfree time, and improve memory use. - Introduce sysctl to set default RPS configuration for new netdevs. - Define Netlink protocol specification format which can be used to describe messages used by each family and auto-generate parsers. Add tools for generating kernel data structures and uAPI headers. - Expose all net/core sysctls inside netns. - Remove 4s sleep in netpoll if carrier is instantly detected on boot. - Add configurable limit of MDB entries per port, and port-vlan. - Continue populating drop reasons throughout the stack. - Retire a handful of legacy Qdiscs and classifiers. Protocols: - Support IPv4 big TCP (TSO frames larger than 64kB). - Add IP_LOCAL_PORT_RANGE socket option, to control local port range on socket by socket basis. - Track and report in procfs number of MPTCP sockets used. - Support mixing IPv4 and IPv6 flows in the in-kernel MPTCP path manager. - IPv6: don't check net.ipv6.route.max_size and rely on garbage collection to free memory (similarly to IPv4). - Support Penultimate Segment Pop (PSP) flavor in SRv6 (RFC8986). - ICMP: add per-rate limit counters. - Add support for user scanning requests in ieee802154. - Remove static WEP support. - Support minimal Wi-Fi 7 Extremely High Throughput (EHT) rate reporting. - WiFi 7 EHT channel puncturing support (client & AP). BPF: - Add a rbtree data structure following the "next-gen data structure" precedent set by recently added linked list, that is, by using kfunc + kptr instead of adding a new BPF map type. - Expose XDP hints via kfuncs with initial support for RX hash and timestamp metadata. - Add BPF_F_NO_TUNNEL_KEY extension to bpf_skb_set_tunnel_key to better support decap on GRE tunnel devices not operating in collect metadata. - Improve x86 JIT's codegen for PROBE_MEM runtime error checks. - Remove the need for trace_printk_lock for bpf_trace_printk and bpf_trace_vprintk helpers. - Extend libbpf's bpf_tracing.h support for tracing arguments of kprobes/uprobes and syscall as a special case. - Significantly reduce the search time for module symbols by livepatch and BPF. - Enable cpumasks to be used as kptrs, which is useful for tracing programs tracking which tasks end up running on which CPUs in different time intervals. - Add support for BPF trampoline on s390x and riscv64. - Add capability to export the XDP features supported by the NIC. - Add __bpf_kfunc tag for marking kernel functions as kfuncs. - Add cgroup.memory=nobpf kernel parameter option to disable BPF memory accounting for container environments. Netfilter: - Remove the CLUSTERIP target. It has been marked as obsolete for years, and we still have WARN splats wrt races of the out-of-band /proc interface installed by this target. - Add 'destroy' commands to nf_tables. They are identical to the existing 'delete' commands, but do not return an error if the referenced object (set, chain, rule...) did not exist. Driver API: - Improve cpumask_local_spread() locality to help NICs set the right IRQ affinity on AMD platforms. - Separate C22 and C45 MDIO bus transactions more clearly. - Introduce new DCB table to control DSCP rewrite on egress. - Support configuration of Physical Layer Collision Avoidance (PLCA) Reconciliation Sublayer (RS) (802.3cg-2019). Modern version of shared medium Ethernet. - Support for MAC Merge layer (IEEE 802.3-2018 clause 99). Allowing preemption of low priority frames by high priority frames. - Add support for controlling MACSec offload using netlink SET. - Rework devlink instance refcounts to allow registration and de-registration under the instance lock. Split the code into multiple files, drop some of the unnecessarily granular locks and factor out common parts of netlink operation handling. - Add TX frame aggregation parameters (for USB drivers). - Add a new attr TCA_EXT_WARN_MSG to report TC (offload) warning messages with notifications for debug. - Allow offloading of UDP NEW connections via act_ct. - Add support for per action HW stats in TC. - Support hardware miss to TC action (continue processing in SW from a specific point in the action chain). - Warn if old Wireless Extension user space interface is used with modern cfg80211/mac80211 drivers. Do not support Wireless Extensions for Wi-Fi 7 devices at all. Everyone should switch to using nl80211 interface instead. - Improve the CAN bit timing configuration. Use extack to return error messages directly to user space, update the SJW handling, including the definition of a new default value that will benefit CAN-FD controllers, by increasing their oscillator tolerance. New hardware / drivers: - Ethernet: - nVidia BlueField-3 support (control traffic driver) - Ethernet support for imx93 SoCs - Motorcomm yt8531 gigabit Ethernet PHY - onsemi NCN26000 10BASE-T1S PHY (with support for PLCA) - Microchip LAN8841 PHY (incl. cable diagnostics and PTP) - Amlogic gxl MDIO mux - WiFi: - RealTek RTL8188EU (rtl8xxxu) - Qualcomm Wi-Fi 7 devices (ath12k) - CAN: - Renesas R-Car V4H Drivers: - Bluetooth: - Set Per Platform Antenna Gain (PPAG) for Intel controllers. - Ethernet NICs: - Intel (1G, igc): - support TSN / Qbv / packet scheduling features of i226 model - Intel (100G, ice): - use GNSS subsystem instead of TTY - multi-buffer XDP support - extend support for GPIO pins to E823 devices - nVidia/Mellanox: - update the shared buffer configuration on PFC commands - implement PTP adjphase function for HW offset control - TC support for Geneve and GRE with VF tunnel offload - more efficient crypto key management method - multi-port eswitch support - Netronome/Corigine: - add DCB IEEE support - support IPsec offloading for NFP3800 - Freescale/NXP (enetc): - support XDP_REDIRECT for XDP non-linear buffers - improve reconfig, avoid link flap and waiting for idle - support MAC Merge layer - Other NICs: - sfc/ef100: add basic devlink support for ef100 - ionic: rx_push mode operation (writing descriptors via MMIO) - bnxt: use the auxiliary bus abstraction for RDMA - r8169: disable ASPM and reset bus in case of tx timeout - cpsw: support QSGMII mode for J721e CPSW9G - cpts: support pulse-per-second output - ngbe: add an mdio bus driver - usbnet: optimize usbnet_bh() by avoiding unnecessary queuing - r8152: handle devices with FW with NCM support - amd-xgbe: support 10Mbps, 2.5GbE speeds and rx-adaptation - virtio-net: support multi buffer XDP - virtio/vsock: replace virtio_vsock_pkt with sk_buff - tsnep: XDP support - Ethernet high-speed switches: - nVidia/Mellanox (mlxsw): - add support for latency TLV (in FW control messages) - Microchip (sparx5): - separate explicit and implicit traffic forwarding rules, make the implicit rules always active - add support for egress DSCP rewrite - IS0 VCAP support (Ingress Classification) - IS2 VCAP filters (protos, L3 addrs, L4 ports, flags, ToS etc.) - ES2 VCAP support (Egress Access Control) - support for Per-Stream Filtering and Policing (802.1Q, 8.6.5.1) - Ethernet embedded switches: - Marvell (mv88e6xxx): - add MAB (port auth) offload support - enable PTP receive for mv88e6390 - NXP (ocelot): - support MAC Merge layer - support for the the vsc7512 internal copper phys - Microchip: - lan9303: convert to PHYLINK - lan966x: support TC flower filter statistics - lan937x: PTP support for KSZ9563/KSZ8563 and LAN937x - lan937x: support Credit Based Shaper configuration - ksz9477: support Energy Efficient Ethernet - other: - qca8k: convert to regmap read/write API, use bulk operations - rswitch: Improve TX timestamp accuracy - Intel WiFi (iwlwifi): - EHT (Wi-Fi 7) rate reporting - STEP equalizer support: transfer some STEP (connection to radio on platforms with integrated wifi) related parameters from the BIOS to the firmware. - Qualcomm 802.11ax WiFi (ath11k): - IPQ5018 support - Fine Timing Measurement (FTM) responder role support - channel 177 support - MediaTek WiFi (mt76): - per-PHY LED support - mt7996: EHT (Wi-Fi 7) support - Wireless Ethernet Dispatch (WED) reset support - switch to using page pool allocator - RealTek WiFi (rtw89): - support new version of Bluetooth co-existance - Mobile: - rmnet: support TX aggregation" * tag 'net-next-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1872 commits) page_pool: add a comment explaining the fragment counter usage net: ethtool: fix __ethtool_dev_mm_supported() implementation ethtool: pse-pd: Fix double word in comments xsk: add linux/vmalloc.h to xsk.c sefltests: netdevsim: wait for devlink instance after netns removal selftest: fib_tests: Always cleanup before exit net/mlx5e: Align IPsec ASO result memory to be as required by hardware net/mlx5e: TC, Set CT miss to the specific ct action instance net/mlx5e: Rename CHAIN_TO_REG to MAPPED_OBJ_TO_REG net/mlx5: Refactor tc miss handling to a single function net/mlx5: Kconfig: Make tc offload depend on tc skb extension net/sched: flower: Support hardware miss to tc action net/sched: flower: Move filter handle initialization earlier net/sched: cls_api: Support hardware miss to tc action net/sched: Rename user cookie and act cookie sfc: fix builds without CONFIG_RTC_LIB sfc: clean up some inconsistent indentings net/mlx4_en: Introduce flexible array to silence overflow warning net: lan966x: Fix possible deadlock inside PTP net/ulp: Remove redundant ->clone() test in inet_clone_ulp(). ...
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+======================
+Linux Kernel Selftests
+======================
+
+The kernel contains a set of "self tests" under the tools/testing/selftests/
+directory. These are intended to be small tests to exercise individual code
+paths in the kernel. Tests are intended to be run after building, installing
+and booting a kernel.
+
+Kselftest from mainline can be run on older stable kernels. Running tests
+from mainline offers the best coverage. Several test rings run mainline
+kselftest suite on stable releases. The reason is that when a new test
+gets added to test existing code to regression test a bug, we should be
+able to run that test on an older kernel. Hence, it is important to keep
+code that can still test an older kernel and make sure it skips the test
+gracefully on newer releases.
+
+You can find additional information on Kselftest framework, how to
+write new tests using the framework on Kselftest wiki:
+
+https://kselftest.wiki.kernel.org/
+
+On some systems, hot-plug tests could hang forever waiting for cpu and
+memory to be ready to be offlined. A special hot-plug target is created
+to run the full range of hot-plug tests. In default mode, hot-plug tests run
+in safe mode with a limited scope. In limited mode, cpu-hotplug test is
+run on a single cpu as opposed to all hotplug capable cpus, and memory
+hotplug test is run on 2% of hotplug capable memory instead of 10%.
+
+kselftest runs as a userspace process. Tests that can be written/run in
+userspace may wish to use the `Test Harness`_. Tests that need to be
+run in kernel space may wish to use a `Test Module`_.
+
+Running the selftests (hotplug tests are run in limited mode)
+=============================================================
+
+To build the tests::
+
+ $ make -C tools/testing/selftests
+
+To run the tests::
+
+ $ make -C tools/testing/selftests run_tests
+
+To build and run the tests with a single command, use::
+
+ $ make kselftest
+
+Note that some tests will require root privileges.
+
+Kselftest supports saving output files in a separate directory and then
+running tests. To locate output files in a separate directory two syntaxes
+are supported. In both cases the working directory must be the root of the
+kernel src. This is applicable to "Running a subset of selftests" section
+below.
+
+To build, save output files in a separate directory with O= ::
+
+ $ make O=/tmp/kselftest kselftest
+
+To build, save output files in a separate directory with KBUILD_OUTPUT ::
+
+ $ export KBUILD_OUTPUT=/tmp/kselftest; make kselftest
+
+The O= assignment takes precedence over the KBUILD_OUTPUT environment
+variable.
+
+The above commands by default run the tests and print full pass/fail report.
+Kselftest supports "summary" option to make it easier to understand the test
+results. Please find the detailed individual test results for each test in
+/tmp/testname file(s) when summary option is specified. This is applicable
+to "Running a subset of selftests" section below.
+
+To run kselftest with summary option enabled ::
+
+ $ make summary=1 kselftest
+
+Running a subset of selftests
+=============================
+
+You can use the "TARGETS" variable on the make command line to specify
+single test to run, or a list of tests to run.
+
+To run only tests targeted for a single subsystem::
+
+ $ make -C tools/testing/selftests TARGETS=ptrace run_tests
+
+You can specify multiple tests to build and run::
+
+ $ make TARGETS="size timers" kselftest
+
+To build, save output files in a separate directory with O= ::
+
+ $ make O=/tmp/kselftest TARGETS="size timers" kselftest
+
+To build, save output files in a separate directory with KBUILD_OUTPUT ::
+
+ $ export KBUILD_OUTPUT=/tmp/kselftest; make TARGETS="size timers" kselftest
+
+Additionally you can use the "SKIP_TARGETS" variable on the make command
+line to specify one or more targets to exclude from the TARGETS list.
+
+To run all tests but a single subsystem::
+
+ $ make -C tools/testing/selftests SKIP_TARGETS=ptrace run_tests
+
+You can specify multiple tests to skip::
+
+ $ make SKIP_TARGETS="size timers" kselftest
+
+You can also specify a restricted list of tests to run together with a
+dedicated skiplist::
+
+ $ make TARGETS="bpf breakpoints size timers" SKIP_TARGETS=bpf kselftest
+
+See the top-level tools/testing/selftests/Makefile for the list of all
+possible targets.
+
+Running the full range hotplug selftests
+========================================
+
+To build the hotplug tests::
+
+ $ make -C tools/testing/selftests hotplug
+
+To run the hotplug tests::
+
+ $ make -C tools/testing/selftests run_hotplug
+
+Note that some tests will require root privileges.
+
+
+Install selftests
+=================
+
+You can use the "install" target of "make" (which calls the `kselftest_install.sh`
+tool) to install selftests in the default location (`tools/testing/selftests/kselftest_install`),
+or in a user specified location via the `INSTALL_PATH` "make" variable.
+
+To install selftests in default location::
+
+ $ make -C tools/testing/selftests install
+
+To install selftests in a user specified location::
+
+ $ make -C tools/testing/selftests install INSTALL_PATH=/some/other/path
+
+Running installed selftests
+===========================
+
+Found in the install directory, as well as in the Kselftest tarball,
+is a script named `run_kselftest.sh` to run the tests.
+
+You can simply do the following to run the installed Kselftests. Please
+note some tests will require root privileges::
+
+ $ cd kselftest_install
+ $ ./run_kselftest.sh
+
+To see the list of available tests, the `-l` option can be used::
+
+ $ ./run_kselftest.sh -l
+
+The `-c` option can be used to run all the tests from a test collection, or
+the `-t` option for specific single tests. Either can be used multiple times::
+
+ $ ./run_kselftest.sh -c bpf -c seccomp -t timers:posix_timers -t timer:nanosleep
+
+For other features see the script usage output, seen with the `-h` option.
+
+Packaging selftests
+===================
+
+In some cases packaging is desired, such as when tests need to run on a
+different system. To package selftests, run::
+
+ $ make -C tools/testing/selftests gen_tar
+
+This generates a tarball in the `INSTALL_PATH/kselftest-packages` directory. By
+default, `.gz` format is used. The tar compression format can be overridden by
+specifying a `FORMAT` make variable. Any value recognized by `tar's auto-compress`_
+option is supported, such as::
+
+ $ make -C tools/testing/selftests gen_tar FORMAT=.xz
+
+`make gen_tar` invokes `make install` so you can use it to package a subset of
+tests by using variables specified in `Running a subset of selftests`_
+section::
+
+ $ make -C tools/testing/selftests gen_tar TARGETS="bpf" FORMAT=.xz
+
+.. _tar's auto-compress: https://www.gnu.org/software/tar/manual/html_node/gzip.html#auto_002dcompress
+
+Contributing new tests
+======================
+
+In general, the rules for selftests are
+
+ * Do as much as you can if you're not root;
+
+ * Don't take too long;
+
+ * Don't break the build on any architecture, and
+
+ * Don't cause the top-level "make run_tests" to fail if your feature is
+ unconfigured.
+
+Contributing new tests (details)
+================================
+
+ * In your Makefile, use facilities from lib.mk by including it instead of
+ reinventing the wheel. Specify flags and binaries generation flags on
+ need basis before including lib.mk. ::
+
+ CFLAGS = $(KHDR_INCLUDES)
+ TEST_GEN_PROGS := close_range_test
+ include ../lib.mk
+
+ * Use TEST_GEN_XXX if such binaries or files are generated during
+ compiling.
+
+ TEST_PROGS, TEST_GEN_PROGS mean it is the executable tested by
+ default.
+
+ TEST_CUSTOM_PROGS should be used by tests that require custom build
+ rules and prevent common build rule use.
+
+ TEST_PROGS are for test shell scripts. Please ensure shell script has
+ its exec bit set. Otherwise, lib.mk run_tests will generate a warning.
+
+ TEST_CUSTOM_PROGS and TEST_PROGS will be run by common run_tests.
+
+ TEST_PROGS_EXTENDED, TEST_GEN_PROGS_EXTENDED mean it is the
+ executable which is not tested by default.
+ TEST_FILES, TEST_GEN_FILES mean it is the file which is used by
+ test.
+
+ * First use the headers inside the kernel source and/or git repo, and then the
+ system headers. Headers for the kernel release as opposed to headers
+ installed by the distro on the system should be the primary focus to be able
+ to find regressions. Use KHDR_INCLUDES in Makefile to include headers from
+ the kernel source.
+
+ * If a test needs specific kernel config options enabled, add a config file in
+ the test directory to enable them.
+
+ e.g: tools/testing/selftests/android/config
+
+ * Create a .gitignore file inside test directory and add all generated objects
+ in it.
+
+ * Add new test name in TARGETS in selftests/Makefile::
+
+ TARGETS += android
+
+ * All changes should pass::
+
+ kselftest-{all,install,clean,gen_tar}
+ kselftest-{all,install,clean,gen_tar} O=abo_path
+ kselftest-{all,install,clean,gen_tar} O=rel_path
+ make -C tools/testing/selftests {all,install,clean,gen_tar}
+ make -C tools/testing/selftests {all,install,clean,gen_tar} O=abs_path
+ make -C tools/testing/selftests {all,install,clean,gen_tar} O=rel_path
+
+Test Module
+===========
+
+Kselftest tests the kernel from userspace. Sometimes things need
+testing from within the kernel, one method of doing this is to create a
+test module. We can tie the module into the kselftest framework by
+using a shell script test runner. ``kselftest/module.sh`` is designed
+to facilitate this process. There is also a header file provided to
+assist writing kernel modules that are for use with kselftest:
+
+- ``tools/testing/selftests/kselftest_module.h``
+- ``tools/testing/selftests/kselftest/module.sh``
+
+Note that test modules should taint the kernel with TAINT_TEST. This will
+happen automatically for modules which are in the ``tools/testing/``
+directory, or for modules which use the ``kselftest_module.h`` header above.
+Otherwise, you'll need to add ``MODULE_INFO(test, "Y")`` to your module
+source. selftests which do not load modules typically should not taint the
+kernel, but in cases where a non-test module is loaded, TEST_TAINT can be
+applied from userspace by writing to ``/proc/sys/kernel/tainted``.
+
+How to use
+----------
+
+Here we show the typical steps to create a test module and tie it into
+kselftest. We use kselftests for lib/ as an example.
+
+1. Create the test module
+
+2. Create the test script that will run (load/unload) the module
+ e.g. ``tools/testing/selftests/lib/printf.sh``
+
+3. Add line to config file e.g. ``tools/testing/selftests/lib/config``
+
+4. Add test script to makefile e.g. ``tools/testing/selftests/lib/Makefile``
+
+5. Verify it works:
+
+.. code-block:: sh
+
+ # Assumes you have booted a fresh build of this kernel tree
+ cd /path/to/linux/tree
+ make kselftest-merge
+ make modules
+ sudo make modules_install
+ make TARGETS=lib kselftest
+
+Example Module
+--------------
+
+A bare bones test module might look like this:
+
+.. code-block:: c
+
+ // SPDX-License-Identifier: GPL-2.0+
+
+ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+ #include "../tools/testing/selftests/kselftest_module.h"
+
+ KSTM_MODULE_GLOBALS();
+
+ /*
+ * Kernel module for testing the foobinator
+ */
+
+ static int __init test_function()
+ {
+ ...
+ }
+
+ static void __init selftest(void)
+ {
+ KSTM_CHECK_ZERO(do_test_case("", 0));
+ }
+
+ KSTM_MODULE_LOADERS(test_foo);
+ MODULE_AUTHOR("John Developer <jd@fooman.org>");
+ MODULE_LICENSE("GPL");
+ MODULE_INFO(test, "Y");
+
+Example test script
+-------------------
+
+.. code-block:: sh
+
+ #!/bin/bash
+ # SPDX-License-Identifier: GPL-2.0+
+ $(dirname $0)/../kselftest/module.sh "foo" test_foo
+
+
+Test Harness
+============
+
+The kselftest_harness.h file contains useful helpers to build tests. The
+test harness is for userspace testing, for kernel space testing see `Test
+Module`_ above.
+
+The tests from tools/testing/selftests/seccomp/seccomp_bpf.c can be used as
+example.
+
+Example
+-------
+
+.. kernel-doc:: tools/testing/selftests/kselftest_harness.h
+ :doc: example
+
+
+Helpers
+-------
+
+.. kernel-doc:: tools/testing/selftests/kselftest_harness.h
+ :functions: TH_LOG TEST TEST_SIGNAL FIXTURE FIXTURE_DATA FIXTURE_SETUP
+ FIXTURE_TEARDOWN TEST_F TEST_HARNESS_MAIN FIXTURE_VARIANT
+ FIXTURE_VARIANT_ADD
+
+Operators
+---------
+
+.. kernel-doc:: tools/testing/selftests/kselftest_harness.h
+ :doc: operators
+
+.. kernel-doc:: tools/testing/selftests/kselftest_harness.h
+ :functions: ASSERT_EQ ASSERT_NE ASSERT_LT ASSERT_LE ASSERT_GT ASSERT_GE
+ ASSERT_NULL ASSERT_TRUE ASSERT_NULL ASSERT_TRUE ASSERT_FALSE
+ ASSERT_STREQ ASSERT_STRNE EXPECT_EQ EXPECT_NE EXPECT_LT
+ EXPECT_LE EXPECT_GT EXPECT_GE EXPECT_NULL EXPECT_TRUE
+ EXPECT_FALSE EXPECT_STREQ EXPECT_STRNE