April 2021 - Linux-kselftest-mirror

[RFC v4 0/2] CPU-Idle latency selftest framework

by Pratik Rajesh Sampat

Changelog v3-->v4 Based on review comments by Doug Smythies, 1. Parsing the thread_siblings_list for CPU topology information to correctly identify the cores the test should run on in default(quick) mode. 2. The source CPU to source CPU interaction in the IPI test will always result in a lower latency and cause a bias in the average, hence avoid adding the latency to be averaged for same cpu IPIs. The latency will still be displayed in the detailed logs. RFC v3: https://lkml.org/lkml/2021/4/4/31 --- A kernel module + userspace driver to estimate the wakeup latency caused by going into stop states. The motivation behind this program is to find significant deviations behind advertised latency and residency values. The patchset measures latencies for two kinds of events. IPIs and Timers As this is a software-only mechanism, there will additional latencies of the kernel-firmware-hardware interactions. To account for that, the program also measures a baseline latency on a 100 percent loaded CPU and the latencies achieved must be in view relative to that. To achieve this, we introduce a kernel module and expose its control knobs through the debugfs interface that the selftests can engage with. The kernel module provides the following interfaces within /sys/kernel/debug/latency_test/ for, IPI test: ipi_cpu_dest = Destination CPU for the IPI ipi_cpu_src = Origin of the IPI ipi_latency_ns = Measured latency time in ns Timeout test: timeout_cpu_src = CPU on which the timer to be queued timeout_expected_ns = Timer duration timeout_diff_ns = Difference of actual duration vs expected timer Sample output on a POWER9 system is as follows: # --IPI Latency Test--- # Baseline Average IPI latency(ns): 3114 # Observed Average IPI latency(ns) - State0: 3265 # Observed Average IPI latency(ns) - State1: 3507 # Observed Average IPI latency(ns) - State2: 3739 # Observed Average IPI latency(ns) - State3: 3807 # Observed Average IPI latency(ns) - State4: 17070 # Observed Average IPI latency(ns) - State5: 1038174 # Observed Average IPI latency(ns) - State6: 1068784 # # --Timeout Latency Test-- # Baseline Average timeout diff(ns): 1420 # Observed Average timeout diff(ns) - State0: 1640 # Observed Average timeout diff(ns) - State1: 1764 # Observed Average timeout diff(ns) - State2: 1715 # Observed Average timeout diff(ns) - State3: 1845 # Observed Average timeout diff(ns) - State4: 16581 # Observed Average timeout diff(ns) - State5: 939977 # Observed Average timeout diff(ns) - State6: 1073024 Things to keep in mind: 1. This kernel module + bash driver does not guarantee idleness on a core when the IPI and the Timer is armed. It only invokes sleep and hopes that the core is idle once the IPI/Timer is invoked onto it. Hence this program must be run on a completely idle system for best results 2. Even on a completely idle system, there maybe book-keeping tasks or jitter tasks that can run on the core we want idle. This can create outliers in the latency measurement. Thankfully, these outliers should be large enough to easily weed them out. 3. A userspace only selftest variant was also sent out as RFC based on suggestions over the previous patchset to simply the kernel complexeity. However, a userspace only approach had more noise in the latency measurement due to userspace-kernel interactions which led to run to run variance and a lesser accurate test. Another downside of the nature of a userspace program is that it takes orders of magnitude longer to complete a full system test compared to the kernel framework. RFC patch: https://lkml.org/lkml/2020/9/2/356 4. For Intel Systems, the Timer based latencies don't exactly give out the measure of idle latencies. This is because of a hardware optimization mechanism that pre-arms a CPU when a timer is set to wakeup. That doesn't make this metric useless for Intel systems, it just means that is measuring IPI/Timer responding latency rather than idle wakeup latencies. (Source: https://lkml.org/lkml/2020/9/2/610) For solution to this problem, a hardware based latency analyzer is devised by Artem Bityutskiy from Intel. https://youtu.be/Opk92aQyvt0?t=8266 https://intel.github.io/wult/ Pratik Rajesh Sampat (2): cpuidle: Extract IPI based and timer based wakeup latency from idle states selftest/cpuidle: Add support for cpuidle latency measurement drivers/cpuidle/Makefile | 1 + drivers/cpuidle/test-cpuidle_latency.c | 157 ++++++++ lib/Kconfig.debug | 10 + tools/testing/selftests/Makefile | 1 + tools/testing/selftests/cpuidle/Makefile | 6 + tools/testing/selftests/cpuidle/cpuidle.sh | 402 +++++++++++++++++++++ tools/testing/selftests/cpuidle/settings | 2 + 7 files changed, 579 insertions(+) create mode 100644 drivers/cpuidle/test-cpuidle_latency.c create mode 100644 tools/testing/selftests/cpuidle/Makefile create mode 100755 tools/testing/selftests/cpuidle/cpuidle.sh create mode 100644 tools/testing/selftests/cpuidle/settings -- 2.17.1

3 years

2
5
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[PATCH] selftests/net: bump timeout to 5 minutes

by Po-Hsu Lin

We found that with the latest mainline kernel (5.12.0-051200rc8) on some KVM instances / bare-metal systems, the following tests will take longer than the kselftest framework default timeout (45 seconds) to run and thus got terminated with TIMEOUT error: * xfrm_policy.sh - took about 2m20s * pmtu.sh - took about 3m5s * udpgso_bench.sh - took about 60s Bump the timeout setting to 5 minutes to allow them have a chance to finish. https://bugs.launchpad.net/bugs/1856010 Signed-off-by: Po-Hsu Lin <po-hsu.lin(a)canonical.com> --- tools/testing/selftests/net/Makefile | 2 ++ tools/testing/selftests/net/settings | 1 + 2 files changed, 3 insertions(+) create mode 100644 tools/testing/selftests/net/settings diff --git a/tools/testing/selftests/net/Makefile b/tools/testing/selftests/net/Makefile index 25f198b..2be4670 100644 --- a/tools/testing/selftests/net/Makefile +++ b/tools/testing/selftests/net/Makefile @@ -37,6 +37,8 @@ TEST_GEN_FILES += ipsec TEST_GEN_PROGS = reuseport_bpf reuseport_bpf_cpu reuseport_bpf_numa TEST_GEN_PROGS += reuseport_dualstack reuseaddr_conflict tls +TEST_FILES := settings + KSFT_KHDR_INSTALL := 1 include ../lib.mk diff --git a/tools/testing/selftests/net/settings b/tools/testing/selftests/net/settings new file mode 100644 index 0000000..694d707 --- /dev/null +++ b/tools/testing/selftests/net/settings @@ -0,0 +1 @@ +timeout=300 -- 2.7.4

3 years

2
1
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[PATCH] selftests/bpf: fix warning comparing pointer to 0

by Jiapeng Chong

Fix the following coccicheck warning: ./tools/testing/selftests/bpf/progs/fentry_test.c:76:15-16: WARNING comparing pointer to 0. Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong(a)linux.alibaba.com> --- tools/testing/selftests/bpf/progs/fentry_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/bpf/progs/fentry_test.c b/tools/testing/selftests/bpf/progs/fentry_test.c index 52a550d..d4247d6 100644 --- a/tools/testing/selftests/bpf/progs/fentry_test.c +++ b/tools/testing/selftests/bpf/progs/fentry_test.c @@ -73,7 +73,7 @@ int BPF_PROG(test7, struct bpf_fentry_test_t *arg) SEC("fentry/bpf_fentry_test8") int BPF_PROG(test8, struct bpf_fentry_test_t *arg) { - if (arg->a == 0) + if (!arg->a) test8_result = 1; return 0; } -- 1.8.3.1

3 years

4
3
0 0

[PATCH v34 00/13] Landlock LSM

by Mickaël Salaün

Hi, This updated patch series adds a new patch on top of the previous ones. It brings a new flag to landlock_create_ruleset(2) that enables efficient and simple backward compatibility checks for future evolutions of Landlock (e.g. new access-control rights). Indeed, it is important to help user space to follow a best-effort security. This new flag is not strictly useful for applications using the current Landlock features but it will be useful when applications developed for newer kernels will be run on older kernels (e.g. the current one). Here is an example of a (work in progress) library using this information to provide a nice backward compatible API: https://github.com/landlock-lsm/rust-landlock The SLOC count is 1331 for security/landlock/ and 2626 for tools/testing/selftest/landlock/ . Test coverage for security/landlock/ is 93.6% of lines: https://landlock.io/linux-lcov/landlock-v34/security/landlock/index.html The code not covered only deals with internal kernel errors (e.g. memory allocation), race conditions and safety checks that should not be triggered. This series is being fuzzed by syzkaller (covering internal kernel errors) that now supports Landlock: https://github.com/google/syzkaller/pull/2380 syzkaller coverage reached 72% (ci-upstream-linux-next-kasan-gce-root): https://syzkaller.appspot.com/upstream The HTML documentation is available here: https://landlock.io/linux-doc/landlock-v34/userspace-api/landlock.html This series can be applied on top of v5.12-rc3 . This can be tested with CONFIG_SECURITY_LANDLOCK, CONFIG_SAMPLE_LANDLOCK and by prepending "landlock," to CONFIG_LSM. This patch series can be found in a Git repository here: https://github.com/landlock-lsm/linux/commits/landlock-v34 This patch series seems ready for upstream and I would really appreciate final reviews. Landlock LSM ============ The goal of Landlock is to enable to restrict ambient rights (e.g. global filesystem access) for a set of processes. Because Landlock is a stackable LSM [1], it makes possible to create safe security sandboxes as new security layers in addition to the existing system-wide access-controls. This kind of sandbox is expected to help mitigate the security impact of bugs or unexpected/malicious behaviors in user-space applications. Landlock empowers any process, including unprivileged ones, to securely restrict themselves. Landlock is inspired by seccomp-bpf but instead of filtering syscalls and their raw arguments, a Landlock rule can restrict the use of kernel objects like file hierarchies, according to the kernel semantic. Landlock also takes inspiration from other OS sandbox mechanisms: XNU Sandbox, FreeBSD Capsicum or OpenBSD Pledge/Unveil. In this current form, Landlock misses some access-control features. This enables to minimize this patch series and ease review. This series still addresses multiple use cases, especially with the combined use of seccomp-bpf: applications with built-in sandboxing, init systems, security sandbox tools and security-oriented APIs [2]. [1] https://lore.kernel.org/lkml/50db058a-7dde-441b-a7f9-f6837fe8b69f@schaufler… [2] https://lore.kernel.org/lkml/f646e1c7-33cf-333f-070c-0a40ad0468cd@digikod.n… Previous versions: v33: https://lore.kernel.org/lkml/20210407160726.542794-1-mic@digikod.net/ v32: https://lore.kernel.org/lkml/20210401205208.2756565-1-mic@digikod.net/ v31: https://lore.kernel.org/lkml/20210324191520.125779-1-mic@digikod.net/ v30: https://lore.kernel.org/lkml/20210316204252.427806-1-mic@digikod.net/ v29: https://lore.kernel.org/lkml/20210225190614.2181147-1-mic@digikod.net/ v28: https://lore.kernel.org/lkml/20210202162710.657398-1-mic@digikod.net/ v27: https://lore.kernel.org/lkml/20210121205119.793296-1-mic@digikod.net/ v26: https://lore.kernel.org/lkml/20201209192839.1396820-1-mic@digikod.net/ v25: https://lore.kernel.org/lkml/20201201192322.213239-1-mic@digikod.net/ v24: https://lore.kernel.org/lkml/20201112205141.775752-1-mic@digikod.net/ v23: https://lore.kernel.org/lkml/20201103182109.1014179-1-mic@digikod.net/ v22: https://lore.kernel.org/lkml/20201027200358.557003-1-mic@digikod.net/ v21: https://lore.kernel.org/lkml/20201008153103.1155388-1-mic@digikod.net/ v20: https://lore.kernel.org/lkml/20200802215903.91936-1-mic@digikod.net/ v19: https://lore.kernel.org/lkml/20200707180955.53024-1-mic@digikod.net/ v18: https://lore.kernel.org/lkml/20200526205322.23465-1-mic@digikod.net/ v17: https://lore.kernel.org/lkml/20200511192156.1618284-1-mic@digikod.net/ v16: https://lore.kernel.org/lkml/20200416103955.145757-1-mic@digikod.net/ v15: https://lore.kernel.org/lkml/20200326202731.693608-1-mic@digikod.net/ v14: https://lore.kernel.org/lkml/20200224160215.4136-1-mic@digikod.net/ v13: https://lore.kernel.org/lkml/20191104172146.30797-1-mic@digikod.net/ v12: https://lore.kernel.org/lkml/20191031164445.29426-1-mic@digikod.net/ v11: https://lore.kernel.org/lkml/20191029171505.6650-1-mic@digikod.net/ v10: https://lore.kernel.org/lkml/20190721213116.23476-1-mic@digikod.net/ v9: https://lore.kernel.org/lkml/20190625215239.11136-1-mic@digikod.net/ v8: https://lore.kernel.org/lkml/20180227004121.3633-1-mic@digikod.net/ v7: https://lore.kernel.org/lkml/20170821000933.13024-1-mic@digikod.net/ v6: https://lore.kernel.org/lkml/20170328234650.19695-1-mic@digikod.net/ v5: https://lore.kernel.org/lkml/20170222012632.4196-1-mic@digikod.net/ v4: https://lore.kernel.org/lkml/20161026065654.19166-1-mic@digikod.net/ v3: https://lore.kernel.org/lkml/20160914072415.26021-1-mic@digikod.net/ v2: https://lore.kernel.org/lkml/1472121165-29071-1-git-send-email-mic@digikod.… v1: https://lore.kernel.org/kernel-hardening/1458784008-16277-1-git-send-email-… Casey Schaufler (1): LSM: Infrastructure management of the superblock Mickaël Salaün (12): landlock: Add object management landlock: Add ruleset and domain management landlock: Set up the security framework and manage credentials landlock: Add ptrace restrictions fs,security: Add sb_delete hook landlock: Support filesystem access-control landlock: Add syscall implementations arch: Wire up Landlock syscalls selftests/landlock: Add user space tests samples/landlock: Add a sandbox manager example landlock: Add user and kernel documentation landlock: Enable user space to infer supported features Documentation/security/index.rst | 1 + Documentation/security/landlock.rst | 85 + Documentation/userspace-api/index.rst | 1 + Documentation/userspace-api/landlock.rst | 311 ++ MAINTAINERS | 15 + arch/Kconfig | 7 + arch/alpha/kernel/syscalls/syscall.tbl | 3 + arch/arm/tools/syscall.tbl | 3 + arch/arm64/include/asm/unistd.h | 2 +- arch/arm64/include/asm/unistd32.h | 6 + arch/ia64/kernel/syscalls/syscall.tbl | 3 + arch/m68k/kernel/syscalls/syscall.tbl | 3 + arch/microblaze/kernel/syscalls/syscall.tbl | 3 + arch/mips/kernel/syscalls/syscall_n32.tbl | 3 + arch/mips/kernel/syscalls/syscall_n64.tbl | 3 + arch/mips/kernel/syscalls/syscall_o32.tbl | 3 + arch/parisc/kernel/syscalls/syscall.tbl | 3 + arch/powerpc/kernel/syscalls/syscall.tbl | 3 + arch/s390/kernel/syscalls/syscall.tbl | 3 + arch/sh/kernel/syscalls/syscall.tbl | 3 + arch/sparc/kernel/syscalls/syscall.tbl | 3 + arch/um/Kconfig | 1 + arch/x86/entry/syscalls/syscall_32.tbl | 3 + arch/x86/entry/syscalls/syscall_64.tbl | 3 + arch/xtensa/kernel/syscalls/syscall.tbl | 3 + fs/super.c | 1 + include/linux/lsm_hook_defs.h | 1 + include/linux/lsm_hooks.h | 4 + include/linux/security.h | 4 + include/linux/syscalls.h | 7 + include/uapi/asm-generic/unistd.h | 8 +- include/uapi/linux/landlock.h | 137 + kernel/sys_ni.c | 5 + samples/Kconfig | 7 + samples/Makefile | 1 + samples/landlock/.gitignore | 1 + samples/landlock/Makefile | 13 + samples/landlock/sandboxer.c | 238 ++ security/Kconfig | 11 +- security/Makefile | 2 + security/landlock/Kconfig | 21 + security/landlock/Makefile | 4 + security/landlock/common.h | 20 + security/landlock/cred.c | 46 + security/landlock/cred.h | 58 + security/landlock/fs.c | 692 ++++ security/landlock/fs.h | 70 + security/landlock/limits.h | 21 + security/landlock/object.c | 67 + security/landlock/object.h | 91 + security/landlock/ptrace.c | 120 + security/landlock/ptrace.h | 14 + security/landlock/ruleset.c | 473 +++ security/landlock/ruleset.h | 165 + security/landlock/setup.c | 40 + security/landlock/setup.h | 18 + security/landlock/syscalls.c | 451 +++ security/security.c | 51 +- security/selinux/hooks.c | 58 +- security/selinux/include/objsec.h | 6 + security/selinux/ss/services.c | 3 +- security/smack/smack.h | 6 + security/smack/smack_lsm.c | 35 +- tools/testing/selftests/Makefile | 1 + tools/testing/selftests/landlock/.gitignore | 2 + tools/testing/selftests/landlock/Makefile | 24 + tools/testing/selftests/landlock/base_test.c | 266 ++ tools/testing/selftests/landlock/common.h | 183 ++ tools/testing/selftests/landlock/config | 7 + tools/testing/selftests/landlock/fs_test.c | 2791 +++++++++++++++++ .../testing/selftests/landlock/ptrace_test.c | 337 ++ tools/testing/selftests/landlock/true.c | 5 + 72 files changed, 6986 insertions(+), 77 deletions(-) create mode 100644 Documentation/security/landlock.rst create mode 100644 Documentation/userspace-api/landlock.rst create mode 100644 include/uapi/linux/landlock.h create mode 100644 samples/landlock/.gitignore create mode 100644 samples/landlock/Makefile create mode 100644 samples/landlock/sandboxer.c create mode 100644 security/landlock/Kconfig create mode 100644 security/landlock/Makefile create mode 100644 security/landlock/common.h create mode 100644 security/landlock/cred.c create mode 100644 security/landlock/cred.h create mode 100644 security/landlock/fs.c create mode 100644 security/landlock/fs.h create mode 100644 security/landlock/limits.h create mode 100644 security/landlock/object.c create mode 100644 security/landlock/object.h create mode 100644 security/landlock/ptrace.c create mode 100644 security/landlock/ptrace.h create mode 100644 security/landlock/ruleset.c create mode 100644 security/landlock/ruleset.h create mode 100644 security/landlock/setup.c create mode 100644 security/landlock/setup.h create mode 100644 security/landlock/syscalls.c create mode 100644 tools/testing/selftests/landlock/.gitignore create mode 100644 tools/testing/selftests/landlock/Makefile create mode 100644 tools/testing/selftests/landlock/base_test.c create mode 100644 tools/testing/selftests/landlock/common.h create mode 100644 tools/testing/selftests/landlock/config create mode 100644 tools/testing/selftests/landlock/fs_test.c create mode 100644 tools/testing/selftests/landlock/ptrace_test.c create mode 100644 tools/testing/selftests/landlock/true.c base-commit: 1e28eed17697bcf343c6743f0028cc3b5dd88bf0 -- 2.31.1

3 years

2
15
0 0

[PATCH 1/2] kunit: introduce kunit_kmalloc_array/kunit_kcalloc() helpers

by Daniel Latypov

Add in: * kunit_kmalloc_array() and wire up kunit_kmalloc() to be a special case of it. * kunit_kcalloc() for symmetry with kunit_kzalloc() This should using KUnit more natural by making it more similar to the existing *alloc() APIs. And while we shouldn't necessarily be writing unit tests where overflow should be a concern, it can't hurt to be safe. Signed-off-by: Daniel Latypov <dlatypov(a)google.com> --- include/kunit/test.h | 36 ++++++++++++++++++++++++++++++++---- lib/kunit/test.c | 22 ++++++++++++---------- 2 files changed, 44 insertions(+), 14 deletions(-) diff --git a/include/kunit/test.h b/include/kunit/test.h index 49601c4b98b8..7fa0de4af977 100644 --- a/include/kunit/test.h +++ b/include/kunit/test.h @@ -577,16 +577,30 @@ static inline int kunit_destroy_named_resource(struct kunit *test, void kunit_remove_resource(struct kunit *test, struct kunit_resource *res); /** - * kunit_kmalloc() - Like kmalloc() except the allocation is *test managed*. + * kunit_kmalloc_array() - Like kmalloc_array() except the allocation is *test managed*. * @test: The test context object. + * @n: number of elements. * @size: The size in bytes of the desired memory. * @gfp: flags passed to underlying kmalloc(). * - * Just like `kmalloc(...)`, except the allocation is managed by the test case + * Just like `kmalloc_array(...)`, except the allocation is managed by the test case * and is automatically cleaned up after the test case concludes. See &struct * kunit_resource for more information. */ -void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp); +void *kunit_kmalloc_array(struct kunit *test, size_t n, size_t size, gfp_t flags); + +/** + * kunit_kmalloc() - Like kmalloc() except the allocation is *test managed*. + * @test: The test context object. + * @size: The size in bytes of the desired memory. + * @gfp: flags passed to underlying kmalloc(). + * + * See kmalloc() and kunit_kmalloc_array() for more information. + */ +static inline void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp) +{ + return kunit_kmalloc_array(test, 1, size, gfp); +} /** * kunit_kfree() - Like kfree except for allocations managed by KUnit. @@ -601,13 +615,27 @@ void kunit_kfree(struct kunit *test, const void *ptr); * @size: The size in bytes of the desired memory. * @gfp: flags passed to underlying kmalloc(). * - * See kzalloc() and kunit_kmalloc() for more information. + * See kzalloc() and kunit_kmalloc_array() for more information. */ static inline void *kunit_kzalloc(struct kunit *test, size_t size, gfp_t gfp) { return kunit_kmalloc(test, size, gfp | __GFP_ZERO); } +/** + * kunit_kzalloc() - Just like kunit_kmalloc_array(), but zeroes the allocation. + * @test: The test context object. + * @n: number of elements. + * @size: The size in bytes of the desired memory. + * @gfp: flags passed to underlying kmalloc(). + * + * See kcalloc() and kunit_kmalloc_array() for more information. + */ +static inline void *kunit_kcalloc(struct kunit *test, size_t n, size_t size, gfp_t flags) +{ + return kunit_kmalloc_array(test, n, size, flags | __GFP_ZERO); +} + void kunit_cleanup(struct kunit *test); void kunit_log_append(char *log, const char *fmt, ...); diff --git a/lib/kunit/test.c b/lib/kunit/test.c index ec9494e914ef..052fccf69eef 100644 --- a/lib/kunit/test.c +++ b/lib/kunit/test.c @@ -540,41 +540,43 @@ int kunit_destroy_resource(struct kunit *test, kunit_resource_match_t match, } EXPORT_SYMBOL_GPL(kunit_destroy_resource); -struct kunit_kmalloc_params { +struct kunit_kmalloc_array_params { + size_t n; size_t size; gfp_t gfp; }; -static int kunit_kmalloc_init(struct kunit_resource *res, void *context) +static int kunit_kmalloc_array_init(struct kunit_resource *res, void *context) { - struct kunit_kmalloc_params *params = context; + struct kunit_kmalloc_array_params *params = context; - res->data = kmalloc(params->size, params->gfp); + res->data = kmalloc_array(params->n, params->size, params->gfp); if (!res->data) return -ENOMEM; return 0; } -static void kunit_kmalloc_free(struct kunit_resource *res) +static void kunit_kmalloc_array_free(struct kunit_resource *res) { kfree(res->data); } -void *kunit_kmalloc(struct kunit *test, size_t size, gfp_t gfp) +void *kunit_kmalloc_array(struct kunit *test, size_t n, size_t size, gfp_t gfp) { - struct kunit_kmalloc_params params = { + struct kunit_kmalloc_array_params params = { .size = size, + .n = n, .gfp = gfp }; return kunit_alloc_resource(test, - kunit_kmalloc_init, - kunit_kmalloc_free, + kunit_kmalloc_array_init, + kunit_kmalloc_array_free, gfp, &params); } -EXPORT_SYMBOL_GPL(kunit_kmalloc); +EXPORT_SYMBOL_GPL(kunit_kmalloc_array); void kunit_kfree(struct kunit *test, const void *ptr) { base-commit: 16fc44d6387e260f4932e9248b985837324705d8 -- 2.31.1.498.g6c1eba8ee3d-goog

3 years

3
3
0 0

[PATCH] selftests/bpf: fix warning comparing pointer to 0

by Jiapeng Chong

Fix the following coccicheck warning: ./tools/testing/selftests/bpf/progs/fentry_test.c:76:15-16: WARNING comparing pointer to 0. Reported-by: Abaci Robot <abaci(a)linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong(a)linux.alibaba.com> --- tools/testing/selftests/bpf/progs/fentry_test.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/tools/testing/selftests/bpf/progs/fentry_test.c b/tools/testing/selftests/bpf/progs/fentry_test.c index 5f645fd..d4247d6 100644 --- a/tools/testing/selftests/bpf/progs/fentry_test.c +++ b/tools/testing/selftests/bpf/progs/fentry_test.c @@ -64,7 +64,7 @@ struct bpf_fentry_test_t { SEC("fentry/bpf_fentry_test7") int BPF_PROG(test7, struct bpf_fentry_test_t *arg) { - if (arg == 0) + if (!arg) test7_result = 1; return 0; } @@ -73,7 +73,7 @@ int BPF_PROG(test7, struct bpf_fentry_test_t *arg) SEC("fentry/bpf_fentry_test8") int BPF_PROG(test8, struct bpf_fentry_test_t *arg) { - if (arg->a == 0) + if (!arg->a) test8_result = 1; return 0; } -- 1.8.3.1

3 years

2
2
0 0

[PATCH v8 6/6] selftest/x86/signal: Include test cases for validating sigaltstack

by Chang S. Bae

The test measures the kernel's signal delivery with different (enough vs. insufficient) stack sizes. Signed-off-by: Chang S. Bae <chang.seok.bae(a)intel.com> Reviewed-by: Len Brown <len.brown(a)intel.com> Cc: x86(a)kernel.org Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org --- Changes from v3: * Revised test messages again (Borislav Petkov) Changes from v2: * Revised test messages (Borislav Petkov) --- tools/testing/selftests/x86/Makefile | 2 +- tools/testing/selftests/x86/sigaltstack.c | 128 ++++++++++++++++++++++ 2 files changed, 129 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/x86/sigaltstack.c diff --git a/tools/testing/selftests/x86/Makefile b/tools/testing/selftests/x86/Makefile index 333980375bc7..65bba2ae86ee 100644 --- a/tools/testing/selftests/x86/Makefile +++ b/tools/testing/selftests/x86/Makefile @@ -13,7 +13,7 @@ CAN_BUILD_WITH_NOPIE := $(shell ./check_cc.sh $(CC) trivial_program.c -no-pie) TARGETS_C_BOTHBITS := single_step_syscall sysret_ss_attrs syscall_nt test_mremap_vdso \ check_initial_reg_state sigreturn iopl ioperm \ test_vsyscall mov_ss_trap \ - syscall_arg_fault fsgsbase_restore + syscall_arg_fault fsgsbase_restore sigaltstack TARGETS_C_32BIT_ONLY := entry_from_vm86 test_syscall_vdso unwind_vdso \ test_FCMOV test_FCOMI test_FISTTP \ vdso_restorer diff --git a/tools/testing/selftests/x86/sigaltstack.c b/tools/testing/selftests/x86/sigaltstack.c new file mode 100644 index 000000000000..f689af75e979 --- /dev/null +++ b/tools/testing/selftests/x86/sigaltstack.c @@ -0,0 +1,128 @@ +// SPDX-License-Identifier: GPL-2.0-only + +#define _GNU_SOURCE +#include <signal.h> +#include <stdio.h> +#include <stdbool.h> +#include <string.h> +#include <err.h> +#include <errno.h> +#include <limits.h> +#include <sys/mman.h> +#include <sys/auxv.h> +#include <sys/prctl.h> +#include <sys/resource.h> +#include <setjmp.h> + +/* sigaltstack()-enforced minimum stack */ +#define ENFORCED_MINSIGSTKSZ 2048 + +#ifndef AT_MINSIGSTKSZ +# define AT_MINSIGSTKSZ 51 +#endif + +static int nerrs; + +static bool sigalrm_expected; + +static unsigned long at_minstack_size; + +static void sethandler(int sig, void (*handler)(int, siginfo_t *, void *), + int flags) +{ + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sa.sa_sigaction = handler; + sa.sa_flags = SA_SIGINFO | flags; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static void clearhandler(int sig) +{ + struct sigaction sa; + + memset(&sa, 0, sizeof(sa)); + sa.sa_handler = SIG_DFL; + sigemptyset(&sa.sa_mask); + if (sigaction(sig, &sa, 0)) + err(1, "sigaction"); +} + +static int setup_altstack(void *start, unsigned long size) +{ + stack_t ss; + + memset(&ss, 0, sizeof(ss)); + ss.ss_size = size; + ss.ss_sp = start; + + return sigaltstack(&ss, NULL); +} + +static jmp_buf jmpbuf; + +static void sigsegv(int sig, siginfo_t *info, void *ctx_void) +{ + if (sigalrm_expected) { + printf("[FAIL]\tWrong signal delivered: SIGSEGV (expected SIGALRM)."); + nerrs++; + } else { + printf("[OK]\tSIGSEGV signal delivered.\n"); + } + + siglongjmp(jmpbuf, 1); +} + +static void sigalrm(int sig, siginfo_t *info, void *ctx_void) +{ + if (!sigalrm_expected) { + printf("[FAIL]\tWrong signal delivered: SIGALRM (expected SIGSEGV)."); + nerrs++; + } else { + printf("[OK]\tSIGALRM signal delivered.\n"); + } +} + +static void test_sigaltstack(void *altstack, unsigned long size) +{ + if (setup_altstack(altstack, size)) + err(1, "sigaltstack()"); + + sigalrm_expected = (size > at_minstack_size) ? true : false; + + sethandler(SIGSEGV, sigsegv, 0); + sethandler(SIGALRM, sigalrm, SA_ONSTACK); + + if (!sigsetjmp(jmpbuf, 1)) { + printf("[RUN]\tTest an alternate signal stack of %ssufficient size.\n", + sigalrm_expected ? "" : "in"); + printf("\tRaise SIGALRM. %s is expected to be delivered.\n", + sigalrm_expected ? "It" : "SIGSEGV"); + raise(SIGALRM); + } + + clearhandler(SIGALRM); + clearhandler(SIGSEGV); +} + +int main(void) +{ + void *altstack; + + at_minstack_size = getauxval(AT_MINSIGSTKSZ); + + altstack = mmap(NULL, at_minstack_size + SIGSTKSZ, PROT_READ | PROT_WRITE, + MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); + if (altstack == MAP_FAILED) + err(1, "mmap()"); + + if ((ENFORCED_MINSIGSTKSZ + 1) < at_minstack_size) + test_sigaltstack(altstack, ENFORCED_MINSIGSTKSZ + 1); + + test_sigaltstack(altstack, at_minstack_size + SIGSTKSZ); + + return nerrs == 0 ? 0 : 1; +} -- 2.17.1

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[PATCH v8 4/6] selftest/sigaltstack: Use the AT_MINSIGSTKSZ aux vector if available

by Chang S. Bae

The SIGSTKSZ constant may not represent enough stack size in some architectures as the hardware state size grows. Use getauxval(AT_MINSIGSTKSZ) to increase the stack size. Signed-off-by: Chang S. Bae <chang.seok.bae(a)intel.com> Reviewed-by: Len Brown <len.brown(a)intel.com> Cc: linux-kselftest(a)vger.kernel.org Cc: linux-kernel(a)vger.kernel.org --- Changes from v5: * Added as a new patch. --- tools/testing/selftests/sigaltstack/sas.c | 20 +++++++++++++++----- 1 file changed, 15 insertions(+), 5 deletions(-) diff --git a/tools/testing/selftests/sigaltstack/sas.c b/tools/testing/selftests/sigaltstack/sas.c index 8934a3766d20..c53b070755b6 100644 --- a/tools/testing/selftests/sigaltstack/sas.c +++ b/tools/testing/selftests/sigaltstack/sas.c @@ -17,6 +17,7 @@ #include <string.h> #include <assert.h> #include <errno.h> +#include <sys/auxv.h> #include "../kselftest.h" @@ -24,6 +25,11 @@ #define SS_AUTODISARM (1U << 31) #endif +#ifndef AT_MINSIGSTKSZ +#define AT_MINSIGSTKSZ 51 +#endif + +static unsigned int stack_size; static void *sstack, *ustack; static ucontext_t uc, sc; static const char *msg = "[OK]\tStack preserved"; @@ -47,7 +53,7 @@ void my_usr1(int sig, siginfo_t *si, void *u) #endif if (sp < (unsigned long)sstack || - sp >= (unsigned long)sstack + SIGSTKSZ) { + sp >= (unsigned long)sstack + stack_size) { ksft_exit_fail_msg("SP is not on sigaltstack\n"); } /* put some data on stack. other sighandler will try to overwrite it */ @@ -108,6 +114,10 @@ int main(void) stack_t stk; int err; + /* Make sure more than the required minimum. */ + stack_size = getauxval(AT_MINSIGSTKSZ) + SIGSTKSZ; + ksft_print_msg("[NOTE]\tthe stack size is %lu\n", stack_size); + ksft_print_header(); ksft_set_plan(3); @@ -117,7 +127,7 @@ int main(void) sigaction(SIGUSR1, &act, NULL); act.sa_sigaction = my_usr2; sigaction(SIGUSR2, &act, NULL); - sstack = mmap(NULL, SIGSTKSZ, PROT_READ | PROT_WRITE, + sstack = mmap(NULL, stack_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); if (sstack == MAP_FAILED) { ksft_exit_fail_msg("mmap() - %s\n", strerror(errno)); @@ -139,7 +149,7 @@ int main(void) } stk.ss_sp = sstack; - stk.ss_size = SIGSTKSZ; + stk.ss_size = stack_size; stk.ss_flags = SS_ONSTACK | SS_AUTODISARM; err = sigaltstack(&stk, NULL); if (err) { @@ -161,7 +171,7 @@ int main(void) } } - ustack = mmap(NULL, SIGSTKSZ, PROT_READ | PROT_WRITE, + ustack = mmap(NULL, stack_size, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_STACK, -1, 0); if (ustack == MAP_FAILED) { ksft_exit_fail_msg("mmap() - %s\n", strerror(errno)); @@ -170,7 +180,7 @@ int main(void) getcontext(&uc); uc.uc_link = NULL; uc.uc_stack.ss_sp = ustack; - uc.uc_stack.ss_size = SIGSTKSZ; + uc.uc_stack.ss_size = stack_size; makecontext(&uc, switch_fn, 0); raise(SIGUSR1); -- 2.17.1

3 years

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[PATCH] selftests: timens: Fix gettime_perf to work on powerpc

by Christophe Leroy

On powerpc: - VDSO library is named linux-vdso32.so.1 or linux-vdso64.so.1 - clock_gettime is named __kernel_clock_gettime() Ensure gettime_perf tries these names before giving up. Signed-off-by: Christophe Leroy <christophe.leroy(a)csgroup.eu> --- tools/testing/selftests/timens/gettime_perf.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/tools/testing/selftests/timens/gettime_perf.c b/tools/testing/selftests/timens/gettime_perf.c index 7bf841a3967b..6b13dc277724 100644 --- a/tools/testing/selftests/timens/gettime_perf.c +++ b/tools/testing/selftests/timens/gettime_perf.c @@ -25,12 +25,20 @@ static void fill_function_pointers(void) if (!vdso) vdso = dlopen("linux-gate.so.1", RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); + if (!vdso) + vdso = dlopen("linux-vdso32.so.1", + RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); + if (!vdso) + vdso = dlopen("linux-vdso64.so.1", + RTLD_LAZY | RTLD_LOCAL | RTLD_NOLOAD); if (!vdso) { pr_err("[WARN]\tfailed to find vDSO\n"); return; } vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__vdso_clock_gettime"); + if (!vdso_clock_gettime) + vdso_clock_gettime = (vgettime_t)dlsym(vdso, "__kernel_clock_gettime"); if (!vdso_clock_gettime) pr_err("Warning: failed to find clock_gettime in vDSO\n"); -- 2.25.0

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[PATCH v3] Documentation: dev-tools: Add Testing Overview

by David Gow

The kernel now has a number of testing and debugging tools, and we've seen a bit of confusion about what the differences between them are. Add a basic documentation outlining the testing tools, when to use each, and how they interact. This is a pretty quick overview rather than the idealised "kernel testing guide" that'd probably be optimal, but given the number of times questions like "When do you use KUnit and when do you use Kselftest?" are being asked, it seemed worth at least having something. Hopefully this can form the basis for more detailed documentation later. Signed-off-by: David Gow <davidgow(a)google.com> Reviewed-by: Marco Elver <elver(a)google.com> Reviewed-by: Daniel Latypov <dlatypov(a)google.com> --- Thanks again. Assuming no-one has any objections, I think this is good to go. -- David Changes since v2: https://lore.kernel.org/linux-kselftest/20210414081428.337494-1-davidgow@go… - A few typo fixes (Thanks Daniel) - Reworded description of dynamic analysis tools. - Updated dev-tools index page to not use ':doc:' syntax, but to provide a path instead. - Added Marco and Daniel's Reviewed-by tags. Changes since v1: https://lore.kernel.org/linux-kselftest/20210410070529.4113432-1-davidgow@g… - Note KUnit's speed and that one should provide selftests for syscalls - Mention lockdep as a Dynamic Analysis Tool - Refer to "Dynamic Analysis Tools" instead of "Sanitizers" - A number of minor formatting tweaks and rewordings for clarity Documentation/dev-tools/index.rst | 4 + Documentation/dev-tools/testing-overview.rst | 117 +++++++++++++++++++ 2 files changed, 121 insertions(+) create mode 100644 Documentation/dev-tools/testing-overview.rst diff --git a/Documentation/dev-tools/index.rst b/Documentation/dev-tools/index.rst index 1b1cf4f5c9d9..929d916ffd4c 100644 --- a/Documentation/dev-tools/index.rst +++ b/Documentation/dev-tools/index.rst @@ -7,6 +7,9 @@ be used to work on the kernel. For now, the documents have been pulled together without any significant effort to integrate them into a coherent whole; patches welcome! +A brief overview of testing-specific tools can be found in +Documentation/dev-tools/testing-overview.rst + .. class:: toc-title Table of contents @@ -14,6 +17,7 @@ whole; patches welcome! .. toctree:: :maxdepth: 2 + testing-overview coccinelle sparse kcov diff --git a/Documentation/dev-tools/testing-overview.rst b/Documentation/dev-tools/testing-overview.rst new file mode 100644 index 000000000000..b5b46709969c --- /dev/null +++ b/Documentation/dev-tools/testing-overview.rst @@ -0,0 +1,117 @@ +.. SPDX-License-Identifier: GPL-2.0 + +==================== +Kernel Testing Guide +==================== + + +There are a number of different tools for testing the Linux kernel, so knowing +when to use each of them can be a challenge. This document provides a rough +overview of their differences, and how they fit together. + + +Writing and Running Tests +========================= + +The bulk of kernel tests are written using either the kselftest or KUnit +frameworks. These both provide infrastructure to help make running tests and +groups of tests easier, as well as providing helpers to aid in writing new +tests. + +If you're looking to verify the behaviour of the Kernel — particularly specific +parts of the kernel — then you'll want to use KUnit or kselftest. + + +The Difference Between KUnit and kselftest +------------------------------------------ + +KUnit (Documentation/dev-tools/kunit/index.rst) is an entirely in-kernel system +for "white box" testing: because test code is part of the kernel, it can access +internal structures and functions which aren't exposed to userspace. + +KUnit tests therefore are best written against small, self-contained parts +of the kernel, which can be tested in isolation. This aligns well with the +concept of 'unit' testing. + +For example, a KUnit test might test an individual kernel function (or even a +single codepath through a function, such as an error handling case), rather +than a feature as a whole. + +This also makes KUnit tests very fast to build and run, allowing them to be +run frequently as part of the development process. + +There is a KUnit test style guide which may give further pointers in +Documentation/dev-tools/kunit/style.rst + + +kselftest (Documentation/dev-tools/kselftest.rst), on the other hand, is +largely implemented in userspace, and tests are normal userspace scripts or +programs. + +This makes it easier to write more complicated tests, or tests which need to +manipulate the overall system state more (e.g., spawning processes, etc.). +However, it's not possible to call kernel functions directly from kselftest. +This means that only kernel functionality which is exposed to userspace somehow +(e.g. by a syscall, device, filesystem, etc.) can be tested with kselftest. To +work around this, some tests include a companion kernel module which exposes +more information or functionality. If a test runs mostly or entirely within the +kernel, however, KUnit may be the more appropriate tool. + +kselftest is therefore suited well to tests of whole features, as these will +expose an interface to userspace, which can be tested, but not implementation +details. This aligns well with 'system' or 'end-to-end' testing. + +For example, all new system calls should be accompanied by kselftest tests. + +Code Coverage Tools +=================== + +The Linux Kernel supports two different code coverage measurement tools. These +can be used to verify that a test is executing particular functions or lines +of code. This is useful for determining how much of the kernel is being tested, +and for finding corner-cases which are not covered by the appropriate test. + +:doc:`gcov` is GCC's coverage testing tool, which can be used with the kernel +to get global or per-module coverage. Unlike KCOV, it does not record per-task +coverage. Coverage data can be read from debugfs, and interpreted using the +usual gcov tooling. + +:doc:`kcov` is a feature which can be built in to the kernel to allow +capturing coverage on a per-task level. It's therefore useful for fuzzing and +other situations where information about code executed during, for example, a +single syscall is useful. + + +Dynamic Analysis Tools +====================== + +The kernel also supports a number of dynamic analysis tools, which attempt to +detect classes of issues when they occur in a running kernel. These typically +each look for a different class of bugs, such as invalid memory accesses, +concurrency issues such as data races, or other undefined behaviour like +integer overflows. + +Some of these tools are listed below: + +* kmemleak detects possible memory leaks. See + Documentation/dev-tools/kmemleak.rst +* KASAN detects invalid memory accesses such as out-of-bounds and + use-after-free errors. See Documentation/dev-tools/kasan.rst +* UBSAN detects behaviour that is undefined by the C standard, like integer + overflows. See Documentation/dev-tools/ubsan.rst +* KCSAN detects data races. See Documentation/dev-tools/kcsan.rst +* KFENCE is a low-overhead detector of memory issues, which is much faster than + KASAN and can be used in production. See Documentation/dev-tools/kfence.rst +* lockdep is a locking correctness validator. See + Documentation/locking/lockdep-design.rst +* There are several other pieces of debug instrumentation in the kernel, many + of which can be found in lib/Kconfig.debug + +These tools tend to test the kernel as a whole, and do not "pass" like +kselftest or KUnit tests. They can be combined with KUnit or kselftest by +running tests on a kernel with these tools enabled: you can then be sure +that none of these errors are occurring during the test. + +Some of these tools integrate with KUnit or kselftest and will +automatically fail tests if an issue is detected. + -- 2.31.1.295.g9ea45b61b8-goog

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