July 2024 - Linux-kselftest-mirror

[RFC PATCH v1 0/4] Add support for the Bus Lock Threshold

by Manali Shukla

Malicious guests can cause bus locks to degrade the performance of a system. Non-WB (write-back) and misaligned locked RMW (read-modify-write) instructions are referred to as "bus locks" and require system wide synchronization among all processors to guarantee the atomicity. The bus locks can impose notable performance penalties for all processors within the system. Support for the Bus Lock Threshold is indicated by CPUID Fn8000_000A_EDX[29] BusLockThreshold=1, the VMCB provides a Bus Lock Threshold enable bit and an unsigned 16-bit Bus Lock Threshold count. VMCB intercept bit VMCB Offset Bits Function 14h 5 Intercept bus lock operations Bus lock threshold count VMCB Offset Bits Function 120h 15:0 Bus lock counter During VMRUN, the bus lock threshold count is fetched and stored in an internal count register. Prior to executing a bus lock within the guest, the processor verifies the count in the bus lock register. If the count is greater than zero, the processor executes the bus lock, reducing the count. However, if the count is zero, the bus lock operation is not performed, and instead, a Bus Lock Threshold #VMEXIT is triggered to transfer control to the Virtual Machine Monitor (VMM). A Bus Lock Threshold #VMEXIT is reported to the VMM with VMEXIT code 0xA5h, VMEXIT_BUSLOCK. EXITINFO1 and EXITINFO2 are set to 0 on a VMEXIT_BUSLOCK. On a #VMEXIT, the processor writes the current value of the Bus Lock Threshold Counter to the VMCB. More details about the Bus Lock Threshold feature can be found in AMD APM [1]. Patches are prepared on kvm-x86/svm (704ec48fc2fb) Testing done: - Added a selftest for the Bus Lock Threadshold functionality. - Tested the Bus Lock Threshold functionality on SEV and SEV-ES guests. - Tested the Bus Lock Threshold functionality on nested guests. Qemu changes can be found on: Repo: https://github.com/AMDESE/qemu.git Branch: buslock_threshold Qemu commandline to use the bus lock threshold functionality: qemu-system-x86_64 -enable-kvm -cpu EPYC-Turin,+svm -M q35,bus-lock-ratelimit=10 \ .. [1]: AMD64 Architecture Programmer's Manual Pub. 24593, April 2024, Vol 2, 15.14.5 Bus Lock Threshold. https://bugzilla.kernel.org/attachment.cgi?id=306250 Manali Shukla (2): x86/cpufeatures: Add CPUID feature bit for the Bus Lock Threshold KVM: x86: nSVM: Implement support for nested Bus Lock Threshold Nikunj A Dadhania (2): KVM: SVM: Enable Bus lock threshold exit KVM: selftests: Add bus lock exit test arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/include/asm/svm.h | 5 +- arch/x86/include/uapi/asm/svm.h | 2 + arch/x86/kvm/governed_features.h | 1 + arch/x86/kvm/svm/nested.c | 25 ++++ arch/x86/kvm/svm/svm.c | 48 ++++++++ arch/x86/kvm/svm/svm.h | 1 + arch/x86/kvm/x86.h | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../selftests/kvm/x86_64/svm_buslock_test.c | 114 ++++++++++++++++++ 10 files changed, 198 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/kvm/x86_64/svm_buslock_test.c base-commit: 704ec48fc2fbd4e41ec982662ad5bf1eee33eeb2 -- 2.34.1

6 months, 3 weeks

3
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[PATCH v4 0/2] selftests/resctrl: SNC kernel support discovery

by Maciej Wieczor-Retman

Changes v4: - Printing SNC warnings at the start of every test. - Printing SNC warnings at the end of every relevant test. - Remove global snc_mode variable, consolidate snc detection functions into one. - Correct minor mistakes. Changes v3: - Reworked patch 2. - Changed minor things in patch 1 like function name and made corrections to the patch message. Changes v2: - Removed patches 2 and 3 since now this part will be supported by the kernel. Sub-Numa Clustering (SNC) allows splitting CPU cores, caches and memory into multiple NUMA nodes. When enabled, NUMA-aware applications can achieve better performance on bigger server platforms. SNC support in the kernel was merged into x86/cache [1]. With SNC enabled and kernel support in place all the tests will function normally (aside from effective cache size). There might be a problem when SNC is enabled but the system is still using an older kernel version without SNC support. Currently the only message displayed in that situation is a guess that SNC might be enabled and is causing issues. That message also is displayed whenever the test fails on an Intel platform. Add a mechanism to discover kernel support for SNC which will add more meaning and certainty to the error message. Add runtime SNC mode detection and verify how reliable that information is. Series was tested on Ice Lake server platforms with SNC disabled, SNC-2 and SNC-4. The tests were also ran with and without kernel support for SNC. Series applies cleanly on kselftest/next. [1] https://lore.kernel.org/all/20240628215619.76401-1-tony.luck@intel.com/ Previous versions of this series: [v1] https://lore.kernel.org/all/cover.1709721159.git.maciej.wieczor-retman@inte… [v2] https://lore.kernel.org/all/cover.1715769576.git.maciej.wieczor-retman@inte… [v3] https://lore.kernel.org/all/cover.1719842207.git.maciej.wieczor-retman@inte… Maciej Wieczor-Retman (2): selftests/resctrl: Adjust effective L3 cache size with SNC enabled selftests/resctrl: Adjust SNC support messages tools/testing/selftests/resctrl/cat_test.c | 8 ++ tools/testing/selftests/resctrl/cmt_test.c | 10 +- tools/testing/selftests/resctrl/mba_test.c | 7 + tools/testing/selftests/resctrl/mbm_test.c | 9 +- tools/testing/selftests/resctrl/resctrl.h | 7 + .../testing/selftests/resctrl/resctrl_tests.c | 8 +- tools/testing/selftests/resctrl/resctrlfs.c | 130 ++++++++++++++++++ 7 files changed, 174 insertions(+), 5 deletions(-) -- 2.45.2

6 months, 3 weeks

2
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[PATCH] kunit: tool: Build compile_commands.json

by Brendan Jackman

compile_commands.json is used by clangd[1] to provide code navigation and completion functionality to editors. See [2] for an example configuration that includes this functionality for VSCode. It can currently be built manually when using kunit.py, by running: ./scripts/clang-tools/gen_compile_commands.py -d .kunit With this change however, it's built automatically so you don't need to manually keep it up to date. Unlike the manual approach, having make build the compile_commands.json means that it appears in the build output tree instead of at the root of the source tree, so you'll need to add --compile-commands-dir= to your clangd args for it to be found. [1] https://clangd.llvm.org/ [2] https://github.com/FlorentRevest/linux-kernel-vscode Signed-off-by: Brendan Jackman <jackmanb(a)google.com> --- tools/testing/kunit/kunit_kernel.py | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py index 7254c110ff23..61931c4926fd 100644 --- a/tools/testing/kunit/kunit_kernel.py +++ b/tools/testing/kunit/kunit_kernel.py @@ -72,7 +72,8 @@ class LinuxSourceTreeOperations: raise ConfigError(e.output.decode()) def make(self, jobs: int, build_dir: str, make_options: Optional[List[str]]) -> None: - command = ['make', 'ARCH=' + self._linux_arch, 'O=' + build_dir, '--jobs=' + str(jobs)] + command = ['make', 'all', 'compile_commands.json', 'ARCH=' + self._linux_arch, + 'O=' + build_dir, '--jobs=' + str(jobs)] if make_options: command.extend(make_options) if self._cross_compile: --- base-commit: 3c999d1ae3c75991902a1a7dad0cb62c2a3008b4 change-id: 20240516-kunit-compile-commands-d994074fc2be Best regards, -- Brendan Jackman <jackmanb(a)google.com>

6 months, 4 weeks

3
2
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[PATCH v3 0/7] iommufd support pasid attach/replace

by Yi Liu

PASID (Process Address Space ID) is a PCIe extension to tag the DMA transactions out of a physical device, and most modern IOMMU hardware have supported PASID granular address translation. So a PASID-capable device can be attached to multiple hwpts (a.k.a. domains), each attachment is tagged with a pasid. This series is based on a preparation series [1], it first adds a missing iommu API to replace domain for a pasid. Based on the iommu pasid attach/ replace/detach APIs, this series adds iommufd APIs for device drivers to attach/replace/detach pasid to/from hwpt per userspace's request, and adds selftest to validate the iommufd APIs. The completed code can be found in below link [2]. Heads up! The existing iommufd selftest was broken, there was a fix [3] to it, but not been upstreamed yet. If want to run the iommufd selftest, please apply that fix. Sorry for the inconvenience. [1] https://lore.kernel.org/linux-iommu/20240628085538.47049-1-yi.l.liu@intel.c… [2] https://github.com/yiliu1765/iommufd/tree/iommufd_pasid [3] https://lore.kernel.org/linux-iommu/20240111073213.180020-1-baolu.lu@linux.… Change log: v3: - Split the set_dev_pasid op enhancements for domain replacement to be a separate series "Make set_dev_pasid op supportting domain replacement" [1]. The below changes are made in the separate series. *) set_dev_pasid() callback should keep the old config if failed to attach to a domain. This simplifies the caller a lot as caller does not need to attach it back to old domain explicitly. This also avoids some corner cases in which the core may do duplicated domain attachment as described in below link (Jason) https://lore.kernel.org/linux-iommu/BN9PR11MB52768C98314A95AFCD2FA6478C0F2@… *) Drop patch 10 of v2 as it's a bug fix and can be submitted separately (Kevin) *) Rebase on top of Baolu's domain_alloc_paging refactor series (Jason) - Drop the attach_data which includes attach_fn and pasid, insteadly passing the pasid through the device attach path. (Jason) - Add a pasid-num-bits property to mock dev to make pasid selftest work (Kevin) v2: https://lore.kernel.org/linux-iommu/20240412081516.31168-1-yi.l.liu@intel.c… - Domain replace for pasid should be handled in set_dev_pasid() callbacks instead of remove_dev_pasid and call set_dev_pasid afteward in iommu layer (Jason) - Make xarray operations more self-contained in iommufd pasid attach/replace/detach (Jason) - Tweak the dev_iommu_get_max_pasids() to allow iommu driver to populate the max_pasids. This makes the iommufd selftest simpler to meet the max_pasids check in iommu_attach_device_pasid() (Jason) v1: https://lore.kernel.org/kvm/20231127063428.127436-1-yi.l.liu@intel.com/#r - Implemnet iommu_replace_device_pasid() to fall back to the original domain if this replacement failed (Kevin) - Add check in do_attach() to check corressponding attach_fn per the pasid value. rfc: https://lore.kernel.org/linux-iommu/20230926092651.17041-1-yi.l.liu@intel.c… Regards, Yi Liu Yi Liu (7): iommu: Introduce a replace API for device pasid iommufd: Pass pasid through the device attach/replace path iommufd: Support attach/replace hwpt per pasid iommufd/selftest: Add set_dev_pasid and remove_dev_pasid in mock iommu iommufd/selftest: Add a helper to get test device iommufd/selftest: Add test ops to test pasid attach/detach iommufd/selftest: Add coverage for iommufd pasid attach/detach drivers/iommu/iommu-priv.h | 3 + drivers/iommu/iommu.c | 80 ++++++- drivers/iommu/iommufd/Makefile | 1 + drivers/iommu/iommufd/device.c | 31 +-- drivers/iommu/iommufd/iommufd_private.h | 15 ++ drivers/iommu/iommufd/iommufd_test.h | 30 +++ drivers/iommu/iommufd/pasid.c | 157 +++++++++++++ drivers/iommu/iommufd/selftest.c | 206 ++++++++++++++++- include/linux/iommufd.h | 6 + tools/testing/selftests/iommu/iommufd.c | 207 ++++++++++++++++++ .../selftests/iommu/iommufd_fail_nth.c | 28 ++- tools/testing/selftests/iommu/iommufd_utils.h | 78 +++++++ 12 files changed, 808 insertions(+), 34 deletions(-) create mode 100644 drivers/iommu/iommufd/pasid.c -- 2.34.1

7 months

4
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[PATCH v2] kselftest: dt: Ignore nodes that have ancestors disabled

by Nícolas F. R. A. Prado

Filter out nodes that have one of its ancestors disabled as they aren't expected to probe. This removes the following false-positive failures on the sc7180-trogdor-lazor-limozeen-nots-r5 platform: /soc@0/geniqup@8c0000/i2c@894000/proximity@28 /soc@0/geniqup@ac0000/spi@a90000/ec@0 /soc@0/remoteproc@62400000/glink-edge/apr /soc@0/remoteproc@62400000/glink-edge/apr/service@3 /soc@0/remoteproc@62400000/glink-edge/apr/service@4 /soc@0/remoteproc@62400000/glink-edge/apr/service@4/clock-controller /soc@0/remoteproc@62400000/glink-edge/apr/service@4/dais /soc@0/remoteproc@62400000/glink-edge/apr/service@7 /soc@0/remoteproc@62400000/glink-edge/apr/service@7/dais /soc@0/remoteproc@62400000/glink-edge/apr/service@8 /soc@0/remoteproc@62400000/glink-edge/apr/service@8/routing /soc@0/remoteproc@62400000/glink-edge/fastrpc /soc@0/remoteproc@62400000/glink-edge/fastrpc/compute-cb@3 /soc@0/remoteproc@62400000/glink-edge/fastrpc/compute-cb@4 /soc@0/remoteproc@62400000/glink-edge/fastrpc/compute-cb@5 /soc@0/spmi@c440000/pmic@0/pon@800/pwrkey Fixes: 14571ab1ad21 ("kselftest: Add new test for detecting unprobed Devicetree devices") Signed-off-by: Nícolas F. R. A. Prado <nfraprado(a)collabora.com> --- Changes in v2: - Rebased on v6.11-rc1 - Link to v1: https://lore.kernel.org/r/20240619-dt-kselftest-parent-disabled-v1-1-b8f7a8… --- tools/testing/selftests/dt/test_unprobed_devices.sh | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/dt/test_unprobed_devices.sh b/tools/testing/selftests/dt/test_unprobed_devices.sh index 2d7e70c5ad2d..5e3f42ef249e 100755 --- a/tools/testing/selftests/dt/test_unprobed_devices.sh +++ b/tools/testing/selftests/dt/test_unprobed_devices.sh @@ -34,8 +34,21 @@ nodes_compatible=$( # Check if node is available if [[ -e "${node}"/status ]]; then status=$(tr -d '\000' < "${node}"/status) - [[ "${status}" != "okay" && "${status}" != "ok" ]] && continue + if [[ "${status}" != "okay" && "${status}" != "ok" ]]; then + if [ -n "${disabled_nodes_regex}" ]; then + disabled_nodes_regex="${disabled_nodes_regex}|${node}" + else + disabled_nodes_regex="${node}" + fi + continue + fi fi + + # Ignore this node if one of its ancestors was disabled + if [ -n "${disabled_nodes_regex}" ]; then + echo "${node}" | grep -q -E "${disabled_nodes_regex}" && continue + fi + echo "${node}" | sed -e 's|\/proc\/device-tree||' done | sort ) --- base-commit: 8400291e289ee6b2bf9779ff1c83a291501f017b change-id: 20240619-dt-kselftest-parent-disabled-2282a7223d26 Best regards, -- Nícolas F. R. A. Prado <nfraprado(a)collabora.com>

7 months

2
2
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[PATCH] KVM: selftests: Add SEV-ES shutdown test

by Peter Gonda

Regression test for ae20eef5 ("KVM: SVM: Update SEV-ES shutdown intercepts with more metadata"). Test confirms userspace is correctly indicated of a guest shutdown not previous behavior of an EINVAL from KVM_RUN. Cc: Paolo Bonzini <pbonzini(a)redhat.com> Cc: Sean Christopherson <seanjc(a)google.com> Cc: Alper Gun <alpergun(a)google.com> Cc: Tom Lendacky <thomas.lendacky(a)amd.com> Cc: Michael Roth <michael.roth(a)amd.com> Cc: kvm(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org Signed-off-by: Peter Gonda <pgonda(a)google.com> --- .../selftests/kvm/x86_64/sev_smoke_test.c | 26 +++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c index 7c70c0da4fb74..04f24d5f09877 100644 --- a/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c +++ b/tools/testing/selftests/kvm/x86_64/sev_smoke_test.c @@ -160,6 +160,30 @@ static void test_sev(void *guest_code, uint64_t policy) kvm_vm_free(vm); } +static void guest_shutdown_code(void) +{ + __asm__ __volatile__("ud2"); +} + +static void test_sev_es_shutdown(void) +{ + struct kvm_vcpu *vcpu; + struct kvm_vm *vm; + + uint32_t type = KVM_X86_SEV_ES_VM; + + vm = vm_sev_create_with_one_vcpu(type, guest_shutdown_code, &vcpu); + + vm_sev_launch(vm, SEV_POLICY_ES, NULL); + + vcpu_run(vcpu); + TEST_ASSERT(vcpu->run->exit_reason == KVM_EXIT_SHUTDOWN, + "Wanted SHUTDOWN, got %s", + exit_reason_str(vcpu->run->exit_reason)); + + kvm_vm_free(vm); +} + int main(int argc, char *argv[]) { TEST_REQUIRE(kvm_cpu_has(X86_FEATURE_SEV)); @@ -171,6 +195,8 @@ int main(int argc, char *argv[]) test_sev(guest_sev_es_code, SEV_POLICY_ES | SEV_POLICY_NO_DBG); test_sev(guest_sev_es_code, SEV_POLICY_ES); + test_sev_es_shutdown(); + if (kvm_has_cap(KVM_CAP_XCRS) && (xgetbv(0) & XFEATURE_MASK_X87_AVX) == XFEATURE_MASK_X87_AVX) { test_sync_vmsa(0); -- 2.45.2.803.g4e1b14247a-goog

7 months, 1 week

3
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[PATCH] MAINTAINERS: Add selftests/x86 entry

by Muhammad Usama Anjum

There are no maintainers specified for tools/testing/selftests/x86. Shuah has mentioned [1] that the patches should go through x86 tree or in special cases directly to Shuah's tree after getting ack-ed from x86 maintainers. Different people have been confused when sending patches as correct maintainers aren't found by get_maintainer.pl script. Fix this by adding entry to MAINTAINERS file. [1] https://lore.kernel.org/all/90dc0dfc-4c67-4ea1-b705-0585d6e2ec47@linuxfound… Signed-off-by: Muhammad Usama Anjum <usama.anjum(a)collabora.com> --- MAINTAINERS | 1 + 1 file changed, 1 insertion(+) diff --git a/MAINTAINERS b/MAINTAINERS index 523d84b2d6139..f3a17e5d954a3 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -24378,6 +24378,7 @@ T: git git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86/core F: Documentation/arch/x86/ F: Documentation/devicetree/bindings/x86/ F: arch/x86/ +F: tools/testing/selftests/x86 X86 ENTRY CODE M: Andy Lutomirski <luto(a)kernel.org> -- 2.39.2

7 months, 1 week

4
7
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[PATCH RFC 0/3] add support for mm-local memory allocations

by Roman Kagan

In a series posted a few years ago [1], a proposal was put forward to allow the kernel to allocate memory local to a mm and thus push it out of reach for current and future speculation-based cross-process attacks. We still believe this is a nice thing to have. However, in the time passed since that post Linux mm has grown quite a few new goodies, so we'd like to explore possibilities to implement this functionality with less effort and churn leveraging the now available facilities. Specifically, this is a proof-of-concept attempt to implement mm-local allocations piggy-backing on memfd_secret(), using regular user addressess but pinning the pages and flipping the user/supervisor flag on the respective PTEs to make them directly accessible from kernel, and sealing the VMA to prevent userland from taking over the address range. The approach allowed to delegate all the heavy lifting -- address management, interactions with the direct map, cleanup on mm teardown -- to the existing infrastructure, and required zero architecture-specific code. Compared to the approach used in the orignal series, where a dedicated kernel address range and thus a dedicated PGD was used for mm-local allocations, the one proposed here may have certain drawbacks, in particular - using user addresses for kernel memory may violate assumptions in various parts of kernel code which we may not have identified with smoke tests we did - the allocated addresses are guessable by the userland (ATM they are even visible in /proc/PID/maps but that's fixable) which may weaken the security posture Also included is a simple test driver and selftest to smoke test and showcase the feature. The code is PoC RFC and lacks a lot of checks and special case handling, but demonstrates the idea. We'd appreciate any feedback on whether it's a viable approach or it should better be abandoned in favor of the one with dedicated PGD / kernel address range or yet something else. [1] https://lore.kernel.org/lkml/20190612170834.14855-1-mhillenb@amazon.de/ Fares Mehanna (2): mseal: expose interface to seal / unseal user memory ranges mm/secretmem: implement mm-local kernel allocations Roman Kagan (1): drivers/misc: add test driver and selftest for proclocal allocator drivers/misc/Makefile | 1 + tools/testing/selftests/proclocal/Makefile | 6 + include/linux/secretmem.h | 8 + mm/internal.h | 7 + drivers/misc/proclocal-test.c | 200 +++++++++++++++++ mm/gup.c | 4 +- mm/mseal.c | 81 ++++--- mm/secretmem.c | 208 ++++++++++++++++++ .../selftests/proclocal/proclocal-test.c | 150 +++++++++++++ drivers/misc/Kconfig | 15 ++ tools/testing/selftests/proclocal/.gitignore | 1 + 11 files changed, 649 insertions(+), 32 deletions(-) create mode 100644 tools/testing/selftests/proclocal/Makefile create mode 100644 drivers/misc/proclocal-test.c create mode 100644 tools/testing/selftests/proclocal/proclocal-test.c create mode 100644 tools/testing/selftests/proclocal/.gitignore -- 2.34.1 Amazon Web Services Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrung: Christian Schlaeger, Jonathan Weiss Eingetragen am Amtsgericht Charlottenburg unter HRB 257764 B Sitz: Berlin Ust-ID: DE 365 538 597

7 months, 2 weeks

4
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[PATCH v3] Documentation: KUnit: Update filename best practices

by Kees Cook

Based on feedback from Linus[1] and follow-up discussions, change the suggested file naming for KUnit tests. Link: https://lore.kernel.org/lkml/CAHk-=wgim6pNiGTBMhP8Kd3tsB7_JTAuvNJ=XYd3wPvvk… [1] Reviewed-by: John Hubbard <jhubbard(a)nvidia.com> Signed-off-by: Kees Cook <kees(a)kernel.org> --- v3: additional clarification v2: https://lore.kernel.org/all/20240720165441.it.320-kees@kernel.org/ Cc: David Gow <davidgow(a)google.com> Cc: Brendan Higgins <brendan.higgins(a)linux.dev> Cc: Rae Moar <rmoar(a)google.com> Cc: John Hubbard <jhubbard(a)nvidia.com> Cc: Jonathan Corbet <corbet(a)lwn.net> Cc: Linus Torvalds <torvalds(a)linux-foundation.org> Cc: linux-kselftest(a)vger.kernel.org Cc: kunit-dev(a)googlegroups.com Cc: linux-doc(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org Cc: linux-hardening(a)vger.kernel.org --- Documentation/dev-tools/kunit/style.rst | 29 +++++++++++++++++-------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/Documentation/dev-tools/kunit/style.rst b/Documentation/dev-tools/kunit/style.rst index b6d0d7359f00..eac81a714a29 100644 --- a/Documentation/dev-tools/kunit/style.rst +++ b/Documentation/dev-tools/kunit/style.rst @@ -188,15 +188,26 @@ For example, a Kconfig entry might look like: Test File and Module Names ========================== -KUnit tests can often be compiled as a module. These modules should be named -after the test suite, followed by ``_test``. If this is likely to conflict with -non-KUnit tests, the suffix ``_kunit`` can also be used. +KUnit tests are often compiled as a separate module. To avoid conflicting +with regular modules, KUnit modules should be named after the test suite, +followed by ``_kunit`` (e.g. if "foobar" is the core module, then +"foobar_kunit" is the KUnit test module). -The easiest way of achieving this is to name the file containing the test suite -``<suite>_test.c`` (or, as above, ``<suite>_kunit.c``). This file should be -placed next to the code under test. +Test source files, whether compiled as a separate module or an +``#include`` in another source file, are best kept in a ``tests/`` +subdirectory to not conflict with other source files (e.g. for +tab-completion). + +Note that the ``_test`` suffix has also been used in some existing +tests. The ``_kunit`` suffix is preferred, as it makes the distinction +between KUnit and non-KUnit tests clearer. + +So for the common case, name the file containing the test suite +``tests/<suite>_kunit.c``. The ``tests`` directory should be placed at +the same level as the code under test. For example, tests for +``lib/string.c`` live in ``lib/tests/string_kunit.c``. If the suite name contains some or all of the name of the test's parent -directory, it may make sense to modify the source filename to reduce redundancy. -For example, a ``foo_firmware`` suite could be in the ``foo/firmware_test.c`` -file. +directory, it may make sense to modify the source filename to reduce +redundancy. For example, a ``foo_firmware`` suite could be in the +``foo/tests/firmware_kunit.c`` file. -- 2.34.1

7 months, 2 weeks

3
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[PATCH v3 0/3] riscv: mm: Extend mappable memory up to hint address

by Charlie Jenkins

On riscv, mmap currently returns an address from the largest address space that can fit entirely inside of the hint address. This makes it such that the hint address is almost never returned. This patch raises the mappable area up to and including the hint address. This allows mmap to often return the hint address, which allows a performance improvement over searching for a valid address as well as making the behavior more similar to other architectures. Note that a previous patch introduced stronger semantics compared to other architectures for riscv mmap. On riscv, mmap will not use bits in the upper bits of the virtual address depending on the hint address. On other architectures, a random address is returned in the address space requested. On all architectures the hint address will be returned if it is available. This allows riscv applications to configure how many bits in the virtual address should be left empty. This has the two benefits of being able to request address spaces that are smaller than the default and doesn't require the application to know the page table layout of riscv. Signed-off-by: Charlie Jenkins <charlie(a)rivosinc.com> --- Changes in v3: - Add back forgotten semi-colon - Fix test cases - Add support for rv32 - Change cover letter name so it's not the same as patch 1 - Link to v2: https://lore.kernel.org/r/20240130-use_mmap_hint_address-v2-0-f34ebfd33053@… Changes in v2: - Add back forgotten "mmap_end = STACK_TOP_MAX" - Link to v1: https://lore.kernel.org/r/20240129-use_mmap_hint_address-v1-0-4c74da813ba1@… --- Charlie Jenkins (3): riscv: mm: Use hint address in mmap if available selftests: riscv: Generalize mm selftests docs: riscv: Define behavior of mmap Documentation/arch/riscv/vm-layout.rst | 16 ++-- arch/riscv/include/asm/processor.h | 27 +++--- tools/testing/selftests/riscv/mm/mmap_bottomup.c | 23 +---- tools/testing/selftests/riscv/mm/mmap_default.c | 23 +---- tools/testing/selftests/riscv/mm/mmap_test.h | 107 ++++++++++++++--------- 5 files changed, 83 insertions(+), 113 deletions(-) --- base-commit: 556e2d17cae620d549c5474b1ece053430cd50bc change-id: 20240119-use_mmap_hint_address-f9f4b1b6f5f1 -- - Charlie

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Linux-kselftest-mirror July 2024