The arm64 Guarded Control Stack (GCS) feature provides support for
hardware protected stacks of return addresses, intended to provide
hardening against return oriented programming (ROP) attacks and to make
it easier to gather call stacks for applications such as profiling.
When GCS is active a secondary stack called the Guarded Control Stack is
maintained, protected with a memory attribute which means that it can
only be written with specific GCS operations. The current GCS pointer
can not be directly written to by userspace. When a BL is executed the
value stored in LR is also pushed onto the GCS, and when a RET is
executed the top of the GCS is popped and compared to LR with a fault
being raised if the values do not match. GCS operations may only be
performed on GCS pages, a data abort is generated if they are not.
The combination of hardware enforcement and lack of extra instructions
in the function entry and exit paths should result in something which
has less overhead and is more difficult to attack than a purely software
implementation like clang's shadow stacks.
This series implements support for managing GCS for KVM guests, it also
includes a fix for S1PIE which has also been sent separately as this
feature is a dependency for GCS. It is based on:
https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-next/gcs
Signed-off-by: Mark Brown <broonie(a)kernel.org>
---
Changes in v14:
- Rebase onto arm64/for-next/gcs which includes all the non-KVM support.
- Manage the fine grained traps for GCS instructions.
- Manage PSTATE.EXLOCK when delivering exceptions to KVM guests.
- Link to v13: https://lore.kernel.org/r/20241001-arm64-gcs-v13-0-222b78d87eee@kernel.org
Changes in v13:
- Rebase onto v6.12-rc1.
- Allocate VM_HIGH_ARCH_6 since protection keys used all the existing
bits.
- Implement mm_release() and free transparently allocated GCSs there.
- Use bit 32 of AT_HWCAP for GCS due to AT_HWCAP2 being filled.
- Since we now only set GCSCRE0_EL1 on change ensure that it is
initialised with GCSPR_EL0 accessible to EL0.
- Fix OOM handling on thread copy.
- Link to v12: https://lore.kernel.org/r/20240829-arm64-gcs-v12-0-42fec947436a@kernel.org
Changes in v12:
- Clarify and simplify the signal handling code so we work with the
register state.
- When checking for write aborts to shadow stack pages ensure the fault
is a data abort.
- Depend on !UPROBES.
- Comment cleanups.
- Link to v11: https://lore.kernel.org/r/20240822-arm64-gcs-v11-0-41b81947ecb5@kernel.org
Changes in v11:
- Remove the dependency on the addition of clone3() support for shadow
stacks, rebasing onto v6.11-rc3.
- Make ID_AA64PFR1_EL1.GCS writeable in KVM.
- Hide GCS registers when GCS is not enabled for KVM guests.
- Require HCRX_EL2.GCSEn if booting at EL1.
- Require that GCSCR_EL1 and GCSCRE0_EL1 be initialised regardless of
if we boot at EL2 or EL1.
- Remove some stray use of bit 63 in signal cap tokens.
- Warn if we see a GCS with VM_SHARED.
- Remove rdundant check for VM_WRITE in fault handling.
- Cleanups and clarifications in the ABI document.
- Clean up and improve documentation of some sync placement.
- Only set the EL0 GCS mode if it's actually changed.
- Various minor fixes and tweaks.
- Link to v10: https://lore.kernel.org/r/20240801-arm64-gcs-v10-0-699e2bd2190b@kernel.org
Changes in v10:
- Fix issues with THP.
- Tighten up requirements for initialising GCSCR*.
- Only generate GCS signal frames for threads using GCS.
- Only context switch EL1 GCS registers if S1PIE is enabled.
- Move context switch of GCSCRE0_EL1 to EL0 context switch.
- Make GCS registers unconditionally visible to userspace.
- Use FHU infrastructure.
- Don't change writability of ID_AA64PFR1_EL1 for KVM.
- Remove unused arguments from alloc_gcs().
- Typo fixes.
- Link to v9: https://lore.kernel.org/r/20240625-arm64-gcs-v9-0-0f634469b8f0@kernel.org
Changes in v9:
- Rebase onto v6.10-rc3.
- Restructure and clarify memory management fault handling.
- Fix up basic-gcs for the latest clone3() changes.
- Convert to newly merged KVM ID register based feature configuration.
- Fixes for NV traps.
- Link to v8: https://lore.kernel.org/r/20240203-arm64-gcs-v8-0-c9fec77673ef@kernel.org
Changes in v8:
- Invalidate signal cap token on stack when consuming.
- Typo and other trivial fixes.
- Don't try to use process_vm_write() on GCS, it intentionally does not
work.
- Fix leak of thread GCSs.
- Rebase onto latest clone3() series.
- Link to v7: https://lore.kernel.org/r/20231122-arm64-gcs-v7-0-201c483bd775@kernel.org
Changes in v7:
- Rebase onto v6.7-rc2 via the clone3() patch series.
- Change the token used to cap the stack during signal handling to be
compatible with GCSPOPM.
- Fix flags for new page types.
- Fold in support for clone3().
- Replace copy_to_user_gcs() with put_user_gcs().
- Link to v6: https://lore.kernel.org/r/20231009-arm64-gcs-v6-0-78e55deaa4dd@kernel.org
Changes in v6:
- Rebase onto v6.6-rc3.
- Add some more gcsb_dsync() barriers following spec clarifications.
- Due to ongoing discussion around clone()/clone3() I've not updated
anything there, the behaviour is the same as on previous versions.
- Link to v5: https://lore.kernel.org/r/20230822-arm64-gcs-v5-0-9ef181dd6324@kernel.org
Changes in v5:
- Don't map any permissions for user GCSs, we always use EL0 accessors
or use a separate mapping of the page.
- Reduce the standard size of the GCS to RLIMIT_STACK/2.
- Enforce a PAGE_SIZE alignment requirement on map_shadow_stack().
- Clarifications and fixes to documentation.
- More tests.
- Link to v4: https://lore.kernel.org/r/20230807-arm64-gcs-v4-0-68cfa37f9069@kernel.org
Changes in v4:
- Implement flags for map_shadow_stack() allowing the cap and end of
stack marker to be enabled independently or not at all.
- Relax size and alignment requirements for map_shadow_stack().
- Add more blurb explaining the advantages of hardware enforcement.
- Link to v3: https://lore.kernel.org/r/20230731-arm64-gcs-v3-0-cddf9f980d98@kernel.org
Changes in v3:
- Rebase onto v6.5-rc4.
- Add a GCS barrier on context switch.
- Add a GCS stress test.
- Link to v2: https://lore.kernel.org/r/20230724-arm64-gcs-v2-0-dc2c1d44c2eb@kernel.org
Changes in v2:
- Rebase onto v6.5-rc3.
- Rework prctl() interface to allow each bit to be locked independently.
- map_shadow_stack() now places the cap token based on the size
requested by the caller not the actual space allocated.
- Mode changes other than enable via ptrace are now supported.
- Expand test coverage.
- Various smaller fixes and adjustments.
- Link to v1: https://lore.kernel.org/r/20230716-arm64-gcs-v1-0-bf567f93bba6@kernel.org
---
Mark Brown (5):
KVM: arm64: Expose S1PIE to guests
arm64/gcs: Ensure FGTs for EL1 GCS instructions are disabled
KVM: arm64: Manage GCS access and registers for guests
KVM: arm64: Set PSTATE.EXLOCK when entering an exception
KVM: selftests: arm64: Add GCS registers to get-reg-list
arch/arm64/include/asm/el2_setup.h | 7 ++++-
arch/arm64/include/asm/kvm_host.h | 12 ++++++++
arch/arm64/include/asm/vncr_mapping.h | 2 ++
arch/arm64/include/uapi/asm/ptrace.h | 2 ++
arch/arm64/kvm/hyp/exception.c | 10 +++++++
arch/arm64/kvm/hyp/include/hyp/sysreg-sr.h | 31 +++++++++++++++++++
arch/arm64/kvm/sys_regs.c | 35 ++++++++++++++++++++--
tools/testing/selftests/kvm/aarch64/get-reg-list.c | 28 +++++++++++++++++
8 files changed, 124 insertions(+), 3 deletions(-)
---
base-commit: ed4983d2da8c3b66ac6d048beb242916bec83522
change-id: 20230303-arm64-gcs-e311ab0d8729
Best regards,
--
Mark Brown <broonie(a)kernel.org>
From: Björn Töpel <bjorn(a)rivosinc.com>
This effectively is a revert of commit 7a6eb7c34a78 ("selftests: Skip
BPF seftests by default"). At the time when this was added, BPF had
"build time dependencies on cutting edge versions". Since then a
number of BPF capable tests has been included in net, hid, sched_ext.
There is no reason not to include BPF by default in the build.
Remove BPF from the selftests skiplist.
Signed-off-by: Björn Töpel <bjorn(a)rivosinc.com>
---
tools/testing/selftests/Makefile | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/tools/testing/selftests/Makefile b/tools/testing/selftests/Makefile
index b38199965f99..88f59a5fef96 100644
--- a/tools/testing/selftests/Makefile
+++ b/tools/testing/selftests/Makefile
@@ -129,10 +129,8 @@ ifeq ($(filter net/lib,$(TARGETS)),)
endif
endif
-# User can optionally provide a TARGETS skiplist. By default we skip
-# BPF since it has cutting edge build time dependencies which require
-# more effort to install.
-SKIP_TARGETS ?= bpf
+# User can optionally provide a TARGETS skiplist.
+SKIP_TARGETS ?=
ifneq ($(SKIP_TARGETS),)
TMP := $(filter-out $(SKIP_TARGETS), $(TARGETS))
override TARGETS := $(TMP)
base-commit: 0c559323bbaabee7346c12e74b497e283aaafef5
--
2.43.0
Hi Linus,
Please pull this kselftest fixes update for Linux 6.12-rc2.
This kselftest fixes update for Linux 6.12-rc2 consists of fixes
to build warnings, install scripts, run-time error path, and
git status cleanups to tests:
-- devices/probe: fix for Python3 regex string syntax warnings
-- clone3: removing unused macro from clone3_cap_checkpoint_restore()
-- vDSO: fix to align getrandom states to cache line
-- core and exec: add missing executables to .gitignore files
-- rtc: change to skip test if /dev/rtc0 can't be accessed
-- timers/posix: fix warn_unused_result result in __fatal_error()
-- breakpoints: fix to detect suspend successful condition correctly
-- hid: fix to install required dependencies to run the test
diff is attached.
thanks,
-- Shuah
----------------------------------------------------------------
The following changes since commit 9852d85ec9d492ebef56dc5f229416c925758edc:
Linux 6.12-rc1 (2024-09-29 15:06:19 -0700)
are available in the Git repository at:
git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest tags/linux_kselftest-fixes-6.12-rc2
for you to fetch changes up to c66be905cda24fb782b91053b196bd2e966f95b7:
selftests: breakpoints: use remaining time to check if suspend succeed (2024-10-02 14:37:30 -0600)
----------------------------------------------------------------
linux_kselftest-fixes-6.12-rc2
This kselftest fixes update for Linux 6.12-rc2 consists of fixes
to build warnings, install scripts, run-time error path, and
git status cleanups to tests:
-- devices/probe: fix for Python3 regex string syntax warnings
-- clone3: removing unused macro from clone3_cap_checkpoint_restore()
-- vDSO: fix to align getrandom states to cache line
-- core and exec: add missing executables to .gitignore files
-- rtc: change to skip test if /dev/rtc0 can't be accessed
-- timers/posix: fix warn_unused_result result in __fatal_error()
-- breakpoints: fix to detect suspend successful condition correctly
-- hid: fix to install required dependencies to run the test
----------------------------------------------------------------
Alessandro Zanni (1):
kselftest/devices/probe: Fix SyntaxWarning in regex strings for Python3
Ba Jing (1):
clone3: clone3_cap_checkpoint_restore: remove unused MAX_PID_NS_LEVEL macro
Jason A. Donenfeld (1):
selftests: vDSO: align getrandom states to cache line
Javier Carrasco (2):
selftests: core: add unshare_test to gitignore
selftests: exec: update gitignore for load_address
Joseph Jang (1):
selftest: rtc: Check if could access /dev/rtc0 before testing
Shuah Khan (1):
selftests:timers: posix_timers: Fix warn_unused_result in __fatal_error()
Yifei Liu (1):
selftests: breakpoints: use remaining time to check if suspend succeed
Yun Lu (1):
selftest: hid: add missing run-hid-tools-tests.sh
.../testing/selftests/breakpoints/step_after_suspend_test.c | 5 ++++-
.../testing/selftests/clone3/clone3_cap_checkpoint_restore.c | 2 --
tools/testing/selftests/core/.gitignore | 1 +
.../selftests/devices/probe/test_discoverable_devices.py | 4 ++--
tools/testing/selftests/exec/.gitignore | 3 ++-
tools/testing/selftests/hid/Makefile | 2 ++
tools/testing/selftests/rtc/rtctest.c | 11 ++++++++++-
tools/testing/selftests/timers/posix_timers.c | 12 ++++++++----
tools/testing/selftests/vDSO/vdso_test_getrandom.c | 8 +++++---
9 files changed, 34 insertions(+), 14 deletions(-)
----------------------------------------------------------------
v2:
- v1 missed the merge window, so while we're at it...
- split changes into two patches instead of one for readability (#1
removes the ioam selftests, #2 adds the updated ioam selftests)
TL;DR This patch comes from a discussion we had with Jakub and Paolo on
aligning the ioam selftests with its new "tunsrc" feature.
This patch updates the IOAM selftests to support the new "tunsrc"
feature of IOAM. As a consequence, some changes were required. For
example, the IPv6 header must be accessed to check some fields (i.e.,
the source address for the "tunsrc" feature), which is not possible
AFAIK with IPv6 raw sockets. The latter is currently used with
IPV6_RECVHOPOPTS and was introduced by commit 187bbb6968af ("selftests:
ioam: refactoring to align with the fix") to fix an issue. But, we
really need packet sockets actually... which is one of the changes in
this patch (see the description of the topology at the top of ioam6.sh
for explanations). Another change is that all IPv6 addresses used in the
topology are now based on the documentation prefix (2001:db8::/32).
Also, the tests have been improved and there are now many more of them.
Overall, the script is more robust.
Justin Iurman (2):
selftests: net: remove ioam tests
selftests: net: add new ioam tests
tools/testing/selftests/net/ioam6.sh | 1832 +++++++++++++++-----
tools/testing/selftests/net/ioam6_parser.c | 1087 ++++++++----
2 files changed, 2129 insertions(+), 790 deletions(-)
--
2.34.1
Currently, the second bridge command overwrites the first one.
Fix this by adding this VID to the interface behind $swp2.
The one_bridge_two_pvids() test intends to check that there is no
leakage of traffic between bridge ports which have a single VLAN - the
PVID VLAN.
Because of a typo, port $swp1 is configured with a PVID twice (second
command overwrites first), and $swp2 isn't configured at all (and since
the bridge vlan_default_pvid property is set to 0, this port will not
have a PVID at all, so it will drop all untagged and priority-tagged
traffic).
So, instead of testing the configuration that was intended, we are
testing a different one, where one port has PVID 2 and the other has
no PVID. This incorrect version of the test should also pass, but is
ineffective for its purpose, so fix the typo.
This typo has an impact on results of the test,
potentially leading to wrong conclusions regarding
the functionality of a network device.
The tests results:
TEST: Switch ports in VLAN-aware bridge with different PVIDs:
Unicast non-IP untagged [ OK ]
Multicast non-IP untagged [ OK ]
Broadcast non-IP untagged [ OK ]
Unicast IPv4 untagged [ OK ]
Multicast IPv4 untagged [ OK ]
Unicast IPv6 untagged [ OK ]
Multicast IPv6 untagged [ OK ]
Unicast non-IP VID 1 [ OK ]
Multicast non-IP VID 1 [ OK ]
Broadcast non-IP VID 1 [ OK ]
Unicast IPv4 VID 1 [ OK ]
Multicast IPv4 VID 1 [ OK ]
Unicast IPv6 VID 1 [ OK ]
Multicast IPv6 VID 1 [ OK ]
Unicast non-IP VID 4094 [ OK ]
Multicast non-IP VID 4094 [ OK ]
Broadcast non-IP VID 4094 [ OK ]
Unicast IPv4 VID 4094 [ OK ]
Multicast IPv4 VID 4094 [ OK ]
Unicast IPv6 VID 4094 [ OK ]
Multicast IPv6 VID 4094 [ OK ]
Fixes: 476a4f05d9b8 ("selftests: forwarding: add a no_forwarding.sh test")
Reviewed-by: Hangbin Liu <liuhangbin(a)gmail.com>
Reviewed-by: Shuah Khan <skhan(a)linuxfoundation.org>
Signed-off-by: Kacper Ludwinski <kac.ludwinski(a)icloud.com>
---
tools/testing/selftests/net/forwarding/no_forwarding.sh | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
v5:
- Add test results impacted by the changes
- Fix typo in commit message
v4:
- Add revision history od this patch
- Add "Reviewed-by:"
- Limit number of characters in commit to 80
- Add impact explanation to commit message
- Link: https://lore.kernel.org/linux-kselftest/20240930063543.94247-1-kac.ludwinsk…
v3:
- Edit commit message
- Add missing Signed-off-by
- Link: https://lore.kernel.org/linux-kselftest/20240927112824.339-1-kac.ludwinski@…
v2:
- Add missing CCs
- Fix typo in commit message
- Add target name
- Link: https://lore.kernel.org/linux-kselftest/fQknN_r6POzmrp8UVjyA3cknLnB1HB9I_jf…
v1:
- Link: https://lore.kernel.org/linux-kselftest/20240925050539.1906-1-kacper@ludwin…
diff --git a/tools/testing/selftests/net/forwarding/no_forwarding.sh b/tools/testing/selftests/net/forwarding/no_forwarding.sh
index 9e677aa64a06..694ece9ba3a7 100755
--- a/tools/testing/selftests/net/forwarding/no_forwarding.sh
+++ b/tools/testing/selftests/net/forwarding/no_forwarding.sh
@@ -202,7 +202,7 @@ one_bridge_two_pvids()
ip link set $swp2 master br0
bridge vlan add dev $swp1 vid 1 pvid untagged
- bridge vlan add dev $swp1 vid 2 pvid untagged
+ bridge vlan add dev $swp2 vid 2 pvid untagged
run_test "Switch ports in VLAN-aware bridge with different PVIDs"
--
2.43.0
Changes since V1:
- V1: https://lore.kernel.org/cover.1724970211.git.reinette.chatre@intel.com/
- V2 contains the same general solutions to stated problem as V1 but these
are now preceded by more fixes (patches 1 to 5) and improved robustness
(patches 6 to 9) to existing tests before the series gets back
to solving the original problem with more confidence in patches 10 to 13.
- The posibility of making "memflush = false" for CMT test was discussed
during V1. Modifying this setting does not have a significant impact on the
observed results that are already well within acceptable range and this
version thus keeps original default. If performance was a goal it may
be possible to do further experimentation where "memflush = false" could
eliminate the need for the sleep(1) within the test wrapper, but
improving the performance is not a goal of this work.
- (New) Support what seems to be unintended ability for user space to provide
parameters to "fill_buf" by making the parsing robust and only support
changing parameters that are supported to be changed. Drop support for
"write" operation since it has never been measured.
- (New) Improve wraparound handling. (Ilpo)
- (New) A couple of new fixes addressing issues discovered during development.
- (Change from V1) To support fill_buf parameters provided by user space as
well as test specific fill_buf parameters struct fill_buf_param is no longer
just a member of struct resctrl_val_param, instead there could be at most
two instances of struct fill_buf_param, the immutable parameters provided
by user space and the parameters used by individual tests. (Ilpo)
- Please see individual patches for detailed changes.
V1 cover:
The resctrl selftests for Memory Bandwidth Allocation (MBA) and Memory
Bandwidth Monitoring (MBM) are failing on some (for example [1]) Emerald
Rapids systems. The test failures result from the following two
properties of these systems:
1) Emerald Rapids systems can have up to 320MB L3 cache. The resctrl
MBA and MBM selftests measure memory traffic for which a hardcoded
250MB buffer has been sufficient so far. On platforms with L3 cache
larger than the buffer, the buffer fits in the L3 cache and thus
no/very little memory traffic is generated during the "memory
bandwidth" tests.
2) Some platform features, for example RAS features or memory
performance features that generate memory traffic may drive accesses
that are counted differently by performance counters and MBM
respectively, for instance generating "overhead" traffic which is not
counted against any specific RMID. Until now these counting
differences have always been "in the noise". On Emerald Rapids
systems the maximum MBA throttling (10% memory bandwidth)
throttles memory bandwidth to where memory accesses by these other
platform features push the memory bandwidth difference between
memory controller performance counters and resctrl (MBM) beyond the
tests' hardcoded tolerance.
Make the tests more robust against platform variations:
1) Let the buffer used by memory bandwidth tests be guided by the size
of the L3 cache.
2) Larger buffers require longer initialization time before the buffer can
be used to measurement. Rework the tests to ensure that buffer
initialization is complete before measurements start.
3) Do not compare performance counters and MBM measurements at low
bandwidth. The value of "low" is hardcoded to 750MiB based on
measurements on Emerald Rapids, Sapphire Rapids, and Ice Lake
systems. This limit is not applicable to AMD systems since it
only applies to the MBA and MBM tests that are isolated to Intel.
[1]
https://ark.intel.com/content/www/us/en/ark/products/237261/intel-xeon-plat…
Reinette Chatre (13):
selftests/resctrl: Make functions only used in same file static
selftests/resctrl: Print accurate buffer size as part of MBM results
selftests/resctrl: Fix memory overflow due to unhandled wraparound
selftests/resctrl: Protect against array overrun during iMC config
parsing
selftests/resctrl: Make wraparound handling obvious
selftests/resctrl: Remove "once" parameter required to be false
selftests/resctrl: Only support measured read operation
selftests/resctrl: Remove unused measurement code
selftests/resctrl: Make benchmark parameter passing robust
selftests/resctrl: Ensure measurements skip initialization of default
benchmark
selftests/resctrl: Use cache size to determine "fill_buf" buffer size
selftests/resctrl: Do not compare performance counters and resctrl at
low bandwidth
selftests/resctrl: Keep results from first test run
tools/testing/selftests/resctrl/cmt_test.c | 37 +-
tools/testing/selftests/resctrl/fill_buf.c | 40 +-
tools/testing/selftests/resctrl/mba_test.c | 52 +-
tools/testing/selftests/resctrl/mbm_test.c | 38 +-
tools/testing/selftests/resctrl/resctrl.h | 73 ++-
.../testing/selftests/resctrl/resctrl_tests.c | 95 +++-
tools/testing/selftests/resctrl/resctrl_val.c | 445 +++++-------------
tools/testing/selftests/resctrl/resctrlfs.c | 17 -
8 files changed, 339 insertions(+), 458 deletions(-)
--
2.46.0
Add Kunit tests for the kernel's implementation of the standard CRC-16
algorithm (<linux/crc16.h>). The test data consists of 100
randomly-generated test cases, validated against a naive CRC-16
implementation.
This test follows roughly the same logic as lib/crc32test.c, but
without the performance measurements.
Signed-off-by: Vinicius Peixoto <vpeixoto(a)lkcamp.dev>
Co-developed-by: Enzo Bertoloti <ebertoloti(a)lkcamp.dev>
Signed-off-by: Enzo Bertoloti <ebertoloti(a)lkcamp.dev>
Co-developed-by: Fabricio Gasperin <fgasperin(a)lkcamp.dev>
Signed-off-by: Fabricio Gasperin <fgasperin(a)lkcamp.dev>
Suggested-by: David Laight <David.Laight(a)ACULAB.COM>
---
Hi all,
This patch was developed during a hackathon organized by LKCAMP [1],
with the objective of writing KUnit tests, both to introduce people to
the kernel development process and to learn about different subsystems
(with the positive side effect of improving the kernel test coverage, of
course).
We noticed there were tests for CRC32 in lib/crc32test.c and thought it
would be nice to have something similar for CRC16, since it seems to be
widely used in network drivers (as well as in some ext4 code).
We would really appreciate any feedback/suggestions on how to improve
this. Thanks! :-)
Link to v1: https://lore.kernel.org/linux-kselftest/20240922232643.535329-1-vpeixoto@lk…
Changes in v2 (suggested by David Laight):
- Use the PRNG from include/linux/prandom.h to generate pseudorandom
data/test cases instead of having them hardcoded as large static
arrays
- Add a naive CRC16 implementation used to validate the kernel's
implementation (instead of having the test case results be hard-coded)
[1] https://lkcamp.dev/about
---
lib/Kconfig.debug | 9 +++
lib/Makefile | 1 +
lib/crc16_kunit.c | 165 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 175 insertions(+)
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 7315f643817ae1021f1e4b3dd27b424f49e3f761..f9617e3054948ce43090f524dc67650e9549cee8 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2850,6 +2850,15 @@ config USERCOPY_KUNIT_TEST
on the copy_to/from_user infrastructure, making sure basic
user/kernel boundary testing is working.
+config CRC16_KUNIT_TEST
+ tristate "KUnit tests for CRC16"
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ select CRC16
+ help
+ Enable this option to run unit tests for the kernel's CRC16
+ implementation (<linux/crc16.h>).
+
config TEST_UDELAY
tristate "udelay test driver"
help
diff --git a/lib/Makefile b/lib/Makefile
index 773adf88af41665b2419202e5427e0513c6becae..1faed6414a85fd366b4966a00e8ba231d7546e14 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -389,6 +389,7 @@ CFLAGS_fortify_kunit.o += $(DISABLE_STRUCTLEAK_PLUGIN)
obj-$(CONFIG_FORTIFY_KUNIT_TEST) += fortify_kunit.o
obj-$(CONFIG_SIPHASH_KUNIT_TEST) += siphash_kunit.o
obj-$(CONFIG_USERCOPY_KUNIT_TEST) += usercopy_kunit.o
+obj-$(CONFIG_CRC16_KUNIT_TEST) += crc16_kunit.o
obj-$(CONFIG_GENERIC_LIB_DEVMEM_IS_ALLOWED) += devmem_is_allowed.o
diff --git a/lib/crc16_kunit.c b/lib/crc16_kunit.c
new file mode 100644
index 0000000000000000000000000000000000000000..7a79989815c451a21210d463729436fcc620d6b3
--- /dev/null
+++ b/lib/crc16_kunit.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnits tests for CRC16.
+ *
+ * Copyright (C) 2024, LKCAMP
+ * Author: Vinicius Peixoto <vpeixoto(a)lkcamp.dev>
+ * Author: Fabricio Gasperin <fgasperin(a)lkcamp.dev>
+ * Author: Enzo Bertoloti <ebertoloti(a)lkcamp.dev>
+ */
+#include <kunit/test.h>
+#include <linux/crc16.h>
+#include <linux/prandom.h>
+
+#define CRC16_KUNIT_DATA_SIZE 4096
+#define CRC16_KUNIT_TEST_SIZE 100
+#define CRC16_KUNIT_SEED 0x12345678
+
+/**
+ * struct crc16_test - CRC16 test data
+ * @crc: initial input value to CRC16
+ * @start: Start index within the data buffer
+ * @length: Length of the data
+ * @crc16: Expected CRC16 value for the test
+ */
+static struct crc16_test {
+ u16 crc;
+ u16 start;
+ u16 length;
+} tests[CRC16_KUNIT_TEST_SIZE];
+
+u8 data[CRC16_KUNIT_DATA_SIZE];
+
+
+/* Naive implementation of CRC16 for validation purposes */
+static inline u16 _crc16_naive_byte(u16 crc, u8 data)
+{
+ u8 i = 0;
+
+ crc ^= (u16) data;
+ for (i = 0; i < 8; i++) {
+ if (crc & 0x01)
+ crc = (crc >> 1) ^ 0xa001;
+ else
+ crc = crc >> 1;
+ }
+
+ return crc;
+}
+
+
+static inline u16 _crc16_naive(u16 crc, u8 *buffer, size_t len)
+{
+ while (len--)
+ crc = _crc16_naive_byte(crc, *buffer++);
+ return crc;
+}
+
+
+/* Small helper for generating pseudorandom 16-bit data */
+static inline u16 _rand16(void)
+{
+ static u32 rand = CRC16_KUNIT_SEED;
+
+ rand = next_pseudo_random32(rand);
+ return rand & 0xFFFF;
+}
+
+
+static int crc16_init_test_data(struct kunit_suite *suite)
+{
+ size_t i;
+
+ /* Fill the data buffer with random bytes */
+ for (i = 0; i < CRC16_KUNIT_DATA_SIZE; i++)
+ data[i] = _rand16() & 0xFF;
+
+ /* Generate random test data while ensuring the random
+ * start + length values won't overflow the 4096-byte
+ * buffer (0x7FF * 2 = 0xFFE < 0x1000)
+ */
+ for (size_t i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
+ tests[i].crc = _rand16();
+ tests[i].start = _rand16() & 0x7FF;
+ tests[i].length = _rand16() & 0x7FF;
+ }
+
+ return 0;
+}
+
+/**
+ * crc16_test_empty - Test crc16 with empty data
+ *
+ * Test crc16 with empty data, the result should be the same as the initial crc
+ */
+static void crc16_test_empty(struct kunit *test)
+{
+ u16 crc;
+
+ crc = crc16(0x00, data, 0);
+ KUNIT_EXPECT_EQ(test, crc, 0);
+ crc = crc16(0xFF, data, 0);
+ KUNIT_EXPECT_EQ(test, crc, 0xFF);
+}
+
+/**
+ * crc16_test_correctness - Test crc16
+ *
+ * Test crc16 against a naive implementation
+ */
+static void crc16_test_correctness(struct kunit *test)
+{
+ size_t i;
+ u16 crc, crc_naive;
+
+ for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
+ crc = crc16(tests[i].crc, data + tests[i].start,
+ tests[i].length);
+ crc_naive = _crc16_naive(tests[i].crc, data + tests[i].start,
+ tests[i].length);
+ KUNIT_EXPECT_EQ(test, crc, crc_naive);
+ }
+}
+
+
+/**
+ * crc16_test_combine - Test split crc16 calculations
+ *
+ * Test crc16 with data split in two parts, the result should be the same as
+ * crc16 with the data combined
+ */
+static void crc16_test_combine(struct kunit *test)
+{
+ size_t i, j;
+ u16 crc, crc_naive;
+
+ for (i = 0; i < CRC16_KUNIT_TEST_SIZE; i++) {
+ crc_naive = crc16(tests[i].crc, data + tests[i].start, tests[i].length);
+ for (j = 0; j < tests[i].length; j++) {
+ crc = crc16(tests[i].crc, data + tests[i].start, j);
+ crc = crc16(crc, data + tests[i].start + j, tests[i].length - j);
+ KUNIT_EXPECT_EQ(test, crc, crc_naive);
+ }
+ }
+}
+
+
+static struct kunit_case crc16_test_cases[] = {
+ KUNIT_CASE(crc16_test_empty),
+ KUNIT_CASE(crc16_test_combine),
+ KUNIT_CASE(crc16_test_correctness),
+ {},
+};
+
+static struct kunit_suite crc16_test_suite = {
+ .name = "crc16",
+ .test_cases = crc16_test_cases,
+ .suite_init = crc16_init_test_data,
+};
+kunit_test_suite(crc16_test_suite);
+
+MODULE_AUTHOR("Fabricio Gasperin <fgasperin(a)lkcamp.dev>");
+MODULE_AUTHOR("Vinicius Peixoto <vpeixoto(a)lkcamp.dev>");
+MODULE_AUTHOR("Enzo Bertoloti <ebertoloti(a)lkcamp.dev>");
+MODULE_DESCRIPTION("Unit tests for crc16");
+MODULE_LICENSE("GPL");
---
base-commit: 9852d85ec9d492ebef56dc5f229416c925758edc
change-id: 20241003-crc16-kunit-127a4dc2b72c
Best regards,
--
Vinicius Peixoto <vpeixoto(a)lkcamp.dev>
Add documentation for the kselftests focused on testing devices and
point to it from the kselftest documentation. There are multiple tests
in this category so the aim of this page is to make it clear when to run
each test.
Signed-off-by: Nícolas F. R. A. Prado <nfraprado(a)collabora.com>
---
This patch depends on patch "kselftest: devices: Add test to detect
missing devices" [1], since this patch documents that test.
[1] https://lore.kernel.org/all/20240928-kselftest-dev-exist-v2-1-fab07de6b80b@…
---
Documentation/dev-tools/kselftest.rst | 9 ++++++
Documentation/dev-tools/testing-devices.rst | 47 +++++++++++++++++++++++++++++
2 files changed, 56 insertions(+)
diff --git a/Documentation/dev-tools/kselftest.rst b/Documentation/dev-tools/kselftest.rst
index f3766e326d1e..fdb1df86783a 100644
--- a/Documentation/dev-tools/kselftest.rst
+++ b/Documentation/dev-tools/kselftest.rst
@@ -31,6 +31,15 @@ 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`_.
+Documentation on the tests
+==========================
+
+For documentation on the kselftests themselves, see:
+
+.. toctree::
+
+ testing-devices
+
Running the selftests (hotplug tests are run in limited mode)
=============================================================
diff --git a/Documentation/dev-tools/testing-devices.rst b/Documentation/dev-tools/testing-devices.rst
new file mode 100644
index 000000000000..ab26adb99051
--- /dev/null
+++ b/Documentation/dev-tools/testing-devices.rst
@@ -0,0 +1,47 @@
+.. SPDX-License-Identifier: GPL-2.0
+.. Copyright (c) 2024 Collabora Ltd
+
+=============================
+Device testing with kselftest
+=============================
+
+
+There are a few different kselftests available for testing devices generically,
+with some overlap in coverage and different requirements. This document aims to
+give an overview of each one.
+
+Note: Paths in this document are relative to the kselftest folder
+(``tools/testing/selftests``).
+
+Device oriented kselftests:
+
+* Devicetree (``dt``)
+
+ * **Coverage**: Probe status for devices described in Devicetree
+ * **Requirements**: None
+
+* Error logs (``devices/error_logs``)
+
+ * **Coverage**: Error (or more critical) log messages presence coming from any
+ device
+ * **Requirements**: None
+
+* Discoverable bus (``devices/probe``)
+
+ * **Coverage**: Presence and probe status of USB or PCI devices that have been
+ described in the reference file
+ * **Requirements**: Manually describe the devices that should be tested in a
+ YAML reference file (see ``devices/probe/boards/google,spherion.yaml`` for
+ an example)
+
+* Exist (``devices/exist``)
+
+ * **Coverage**: Presence of all devices
+ * **Requirements**: Generate the reference (see ``devices/exist/README.rst``
+ for details) on a known-good kernel
+
+Therefore, the suggestion is to enable the error log and devicetree tests on all
+(DT-based) platforms, since they don't have any requirements. Then to greatly
+improve coverage, generate the reference for each platform and enable the exist
+test. The discoverable bus test can be used to verify the probe status of
+specific USB or PCI devices, but is probably not worth it for most cases.
---
base-commit: cea5425829f77e476b03702426f6b3701299b925
change-id: 20241001-kselftest-device-docs-6c8a411109b5
Best regards,
--
Nícolas F. R. A. Prado <nfraprado(a)collabora.com>