March 2021 - Linux-kselftest-mirror

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

by Pratik Rajesh Sampat

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 | 316 +++++++++++++++++++++ tools/testing/selftests/cpuidle/settings | 2 + 7 files changed, 493 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, 1 month

3
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[RFC PATCH v4 0/9] KVM: selftests: some improvement and a new test for kvm page table

by Yanan Wang

Hi, This v4 series can mainly include two parts. Based on kvm queue branch: https://git.kernel.org/pub/scm/virt/kvm/kvm.git/log/?h=queue Links of v1: https://lore.kernel.org/lkml/20210208090841.333724-1-wangyanan55@huawei.com/ Links of v2: https://lore.kernel.org/lkml/20210225055940.18748-1-wangyanan55@huawei.com/ Links of v3: https://lore.kernel.org/lkml/20210301065916.11484-1-wangyanan55@huawei.com/ In the first part, all the known hugetlb backing src types specified with different hugepage sizes are listed, so that we can specify use of hugetlb source of the exact granularity that we want, instead of the system default ones. And as all the known hugetlb page sizes are listed, it's appropriate for all architectures. Besides, a helper that can get granularity of different backing src types(anonumous/thp/hugetlb) is added, so that we can use the accurate backing src granularity for kinds of alignment or guest memory accessing of vcpus. In the second part, a new test is added: This test is added to serve as a performance tester and a bug reproducer for kvm page table code (GPA->HPA mappings), it gives guidance for the people trying to make some improvement for kvm. And the following explains what we can exactly do through this test. The function guest_code() can cover the conditions where a single vcpu or multiple vcpus access guest pages within the same memory region, in three VM stages(before dirty logging, during dirty logging, after dirty logging). Besides, the backing src memory type(ANONYMOUS/THP/HUGETLB) of the tested memory region can be specified by users, which means normal page mappings or block mappings can be chosen by users to be created in the test. If ANONYMOUS memory is specified, kvm will create normal page mappings for the tested memory region before dirty logging, and update attributes of the page mappings from RO to RW during dirty logging. If THP/HUGETLB memory is specified, kvm will create block mappings for the tested memory region before dirty logging, and split the blcok mappings into normal page mappings during dirty logging, and coalesce the page mappings back into block mappings after dirty logging is stopped. So in summary, as a performance tester, this test can present the performance of kvm creating/updating normal page mappings, or the performance of kvm creating/splitting/recovering block mappings, through execution time. When we need to coalesce the page mappings back to block mappings after dirty logging is stopped, we have to firstly invalidate *all* the TLB entries for the page mappings right before installation of the block entry, because a TLB conflict abort error could occur if we can't invalidate the TLB entries fully. We have hit this TLB conflict twice on aarch64 software implementation and fixed it. As this test can imulate process from dirty logging enabled to dirty logging stopped of a VM with block mappings, so it can also reproduce this TLB conflict abort due to inadequate TLB invalidation when coalescing tables. Links about the TLB conflict abort: https://lore.kernel.org/lkml/20201201201034.116760-3-wangyanan55@huawei.com/ --- Change logs: v3->v4: - Add a helper to get system default hugetlb page size - Add tags of Reviewed-by of Ben in the patches v2->v3: - Add tags of Suggested-by, Reviewed-by in the patches - Add a generic micro to get hugetlb page sizes - Some changes for suggestions about v2 series v1->v2: - Add a patch to sync header files - Add helpers to get granularity of different backing src types - Some changes for suggestions about v1 series --- Yanan Wang (9): tools headers: sync headers of asm-generic/hugetlb_encode.h tools headers: Add a macro to get HUGETLB page sizes for mmap KVM: selftests: Use flag CLOCK_MONOTONIC_RAW for timing KVM: selftests: Make a generic helper to get vm guest mode strings KVM: selftests: Add a helper to get system configured THP page size KVM: selftests: Add a helper to get system default hugetlb page size KVM: selftests: List all hugetlb src types specified with page sizes KVM: selftests: Adapt vm_userspace_mem_region_add to new helpers KVM: selftests: Add a test for kvm page table code include/uapi/linux/mman.h | 2 + tools/include/asm-generic/hugetlb_encode.h | 3 + tools/include/uapi/linux/mman.h | 2 + tools/testing/selftests/kvm/Makefile | 3 + .../selftests/kvm/demand_paging_test.c | 8 +- .../selftests/kvm/dirty_log_perf_test.c | 14 +- .../testing/selftests/kvm/include/kvm_util.h | 4 +- .../testing/selftests/kvm/include/test_util.h | 21 +- .../selftests/kvm/kvm_page_table_test.c | 476 ++++++++++++++++++ tools/testing/selftests/kvm/lib/kvm_util.c | 59 ++- tools/testing/selftests/kvm/lib/test_util.c | 122 ++++- tools/testing/selftests/kvm/steal_time.c | 4 +- 12 files changed, 659 insertions(+), 59 deletions(-) create mode 100644 tools/testing/selftests/kvm/kvm_page_table_test.c -- 2.19.1

3 years, 1 month

3
24
0 0

[PATCH bpf-next 0/2] add support for batched ops in LPM trie

by Pedro Tammela

The patch itself is straightforward thanks to the infrastructure that is already in-place. The tests follows the other '*_map_batch_ops' tests with minor tweaks. Pedro Tammela (2): bpf: add support for batched operations in LPM trie maps bpf: selftests: add tests for batched ops in LPM trie maps kernel/bpf/lpm_trie.c | 3 + .../map_tests/lpm_trie_map_batch_ops.c (new) | 158 ++++++++++++++++++ 2 files changed, 161 insertions(+) create mode 100644 tools/testing/selftests/bpf/map_tests/lpm_trie_map_batch_ops.c -- 2.25.1

3 years, 1 month

1
2
0 0

[PATCH] selftests: net: forwarding: Fix a typo

by Bhaskar Chowdhury

s/verfied/verified/ Signed-off-by: Bhaskar Chowdhury <unixbhaskar(a)gmail.com> --- tools/testing/selftests/net/forwarding/fib_offload_lib.sh | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/net/forwarding/fib_offload_lib.sh b/tools/testing/selftests/net/forwarding/fib_offload_lib.sh index 66496659bea7..e134a5f529c9 100644 --- a/tools/testing/selftests/net/forwarding/fib_offload_lib.sh +++ b/tools/testing/selftests/net/forwarding/fib_offload_lib.sh @@ -224,7 +224,7 @@ fib_ipv4_plen_test() ip -n $ns link set dev dummy1 up # Add two routes with the same key and different prefix length and - # make sure both are in hardware. It can be verfied that both are + # make sure both are in hardware. It can be verified that both are # sharing the same leaf by checking the /proc/net/fib_trie ip -n $ns route add 192.0.2.0/24 dev dummy1 ip -n $ns route add 192.0.2.0/25 dev dummy1 -- 2.26.2

3 years, 2 months

2
1
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Re: [PATCH v30 10/12] selftests/landlock: Add user space tests

by Kees Cook

On Tue, Mar 16, 2021 at 09:42:50PM +0100, Mickaël Salaün wrote: > From: Mickaël Salaün <mic(a)linux.microsoft.com> > > Test all Landlock system calls, ptrace hooks semantic and filesystem > access-control with multiple layouts. > > Test coverage for security/landlock/ is 93.6% of lines. The code not > covered only deals with internal kernel errors (e.g. memory allocation) > and race conditions. > > Cc: James Morris <jmorris(a)namei.org> > Cc: Jann Horn <jannh(a)google.com> > Cc: Kees Cook <keescook(a)chromium.org> > Cc: Serge E. Hallyn <serge(a)hallyn.com> > Cc: Shuah Khan <shuah(a)kernel.org> > Signed-off-by: Mickaël Salaün <mic(a)linux.microsoft.com> > Reviewed-by: Vincent Dagonneau <vincent.dagonneau(a)ssi.gouv.fr> > Link: https://lore.kernel.org/r/20210316204252.427806-11-mic@digikod.net This is terrific. I love the coverage. How did you measure this, BTW? To increase it into memory allocation failures, have you tried allocation fault injection: https://www.kernel.org/doc/html/latest/fault-injection/fault-injection.html > [...] > +TEST(inconsistent_attr) { > + const long page_size = sysconf(_SC_PAGESIZE); > + char *const buf = malloc(page_size + 1); > + struct landlock_ruleset_attr *const ruleset_attr = (void *)buf; > + > + ASSERT_NE(NULL, buf); > + > + /* Checks copy_from_user(). */ > + ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 0, 0)); > + /* The size if less than sizeof(struct landlock_attr_enforce). */ > + ASSERT_EQ(EINVAL, errno); > + ASSERT_EQ(-1, landlock_create_ruleset(ruleset_attr, 1, 0)); > + ASSERT_EQ(EINVAL, errno); Almost everywhere you're using ASSERT instead of EXPECT. Is this correct (in the sense than as soon as an ASSERT fails the rest of the test is skipped)? I do see you using EXPECT is some places, but I figured I'd ask about the intention here. > +/* > + * TEST_F_FORK() is useful when a test drop privileges but the corresponding > + * FIXTURE_TEARDOWN() requires them (e.g. to remove files from a directory > + * where write actions are denied). For convenience, FIXTURE_TEARDOWN() is > + * also called when the test failed, but not when FIXTURE_SETUP() failed. For > + * this to be possible, we must not call abort() but instead exit smoothly > + * (hence the step print). > + */ Hm, interesting. I think this should be extracted into a separate patch and added to the test harness proper. Could this be solved with TEARDOWN being called on SETUP failure? > +#define TEST_F_FORK(fixture_name, test_name) \ > + static void fixture_name##_##test_name##_child( \ > + struct __test_metadata *_metadata, \ > + FIXTURE_DATA(fixture_name) *self, \ > + const FIXTURE_VARIANT(fixture_name) *variant); \ > + TEST_F(fixture_name, test_name) \ > + { \ > + int status; \ > + const pid_t child = fork(); \ > + if (child < 0) \ > + abort(); \ > + if (child == 0) { \ > + _metadata->no_print = 1; \ > + fixture_name##_##test_name##_child(_metadata, self, variant); \ > + if (_metadata->skip) \ > + _exit(255); \ > + if (_metadata->passed) \ > + _exit(0); \ > + _exit(_metadata->step); \ > + } \ > + if (child != waitpid(child, &status, 0)) \ > + abort(); \ > + if (WIFSIGNALED(status) || !WIFEXITED(status)) { \ > + _metadata->passed = 0; \ > + _metadata->step = 1; \ > + return; \ > + } \ > + switch (WEXITSTATUS(status)) { \ > + case 0: \ > + _metadata->passed = 1; \ > + break; \ > + case 255: \ > + _metadata->passed = 1; \ > + _metadata->skip = 1; \ > + break; \ > + default: \ > + _metadata->passed = 0; \ > + _metadata->step = WEXITSTATUS(status); \ > + break; \ > + } \ > + } \ This looks like a subset of __wait_for_test()? Could __TEST_F_IMPL() be updated instead to do this? (Though the fork overhead might not be great for everyone.) -- Kees Cook

3 years, 2 months

2
3
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[PATCH 1/2] selftests: add a kselftest for SLUB debugging functionality

by glittao＠gmail.com

From: Oliver Glitta <glittao(a)gmail.com> SLUB has resiliency_test() function which is hidden behind #ifdef SLUB_RESILIENCY_TEST that is not part of Kconfig, so nobody runs it. Kselftest should proper replacement for it. Try changing byte in redzone after allocation and changing pointer to next free node, first byte, 50th byte and redzone byte. Check if validation finds errors. There are several differences from the original resiliency test: Tests create own caches with known state instead of corrupting shared kmalloc caches. The corruption of freepointer uses correct offset, the original resiliency test got broken with freepointer changes. Scratch changing random byte test, because it does not have meaning in this form where we need deterministic results. Add new option CONFIG_TEST_SLUB in Kconfig. Add parameter to function validate_slab_cache() to return number of errors in cache. Signed-off-by: Oliver Glitta <glittao(a)gmail.com> --- lib/Kconfig.debug | 4 + lib/Makefile | 1 + lib/test_slub.c | 125 +++++++++++++++++++++++++++ mm/slab.h | 1 + mm/slub.c | 34 +++++--- tools/testing/selftests/lib/Makefile | 2 +- tools/testing/selftests/lib/config | 1 + tools/testing/selftests/lib/slub.sh | 3 + 8 files changed, 159 insertions(+), 12 deletions(-) create mode 100644 lib/test_slub.c create mode 100755 tools/testing/selftests/lib/slub.sh diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 2779c29d9981..2d56092abbc4 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -2123,6 +2123,10 @@ config TEST_KSTRTOX config TEST_PRINTF tristate "Test printf() family of functions at runtime" +config TEST_SLUB + tristate "Test SLUB cache errors at runtime" + depends on SLUB_DEBUG + config TEST_BITMAP tristate "Test bitmap_*() family of functions at runtime" help diff --git a/lib/Makefile b/lib/Makefile index b5307d3eec1a..b6603803b1c4 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -83,6 +83,7 @@ obj-$(CONFIG_TEST_USER_COPY) += test_user_copy.o obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o obj-$(CONFIG_TEST_PRINTF) += test_printf.o +obj-$(CONFIG_TEST_SLUB) += test_slub.o obj-$(CONFIG_TEST_BITMAP) += test_bitmap.o obj-$(CONFIG_TEST_STRSCPY) += test_strscpy.o obj-$(CONFIG_TEST_UUID) += test_uuid.o diff --git a/lib/test_slub.c b/lib/test_slub.c new file mode 100644 index 000000000000..0075d9b44251 --- /dev/null +++ b/lib/test_slub.c @@ -0,0 +1,125 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Test cases for slub facility. + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/module.h> +#include <linux/kernel.h> +#include "../mm/slab.h" + +#include "../tools/testing/selftests/kselftest_module.h" + + +KSTM_MODULE_GLOBALS(); + + +static void __init validate_result(struct kmem_cache *s, int expected_errors) +{ + int errors = 0; + + validate_slab_cache(s, &errors); + KSTM_CHECK_ZERO(errors - expected_errors); +} + +static void __init test_clobber_zone(void) +{ + struct kmem_cache *s = kmem_cache_create("TestSlub_RZ_alloc", 64, 0, + SLAB_RED_ZONE, NULL); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + p[64] = 0x12; + pr_err("1. kmem_cache: Clobber Redzone 0x12->0x%p\n", p + 64); + + validate_result(s, 1); + kmem_cache_free(s, p); + kmem_cache_destroy(s); +} + +static void __init test_next_pointer(void) +{ + struct kmem_cache *s = kmem_cache_create("TestSlub_next_ptr_free", 64, 0, + SLAB_RED_ZONE, NULL); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kmem_cache_free(s, p); + p[s->offset] = 0x12; + pr_err("1. kmem_cache: Clobber next pointer 0x34 -> -0x%p\n", p); + + validate_result(s, 1); + kmem_cache_destroy(s); +} + +static void __init test_first_word(void) +{ + struct kmem_cache *s = kmem_cache_create("TestSlub_1th_word_free", 64, 0, + SLAB_POISON, NULL); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kmem_cache_free(s, p); + *p = 0x78; + pr_err("2. kmem_cache: Clobber first word 0x78->0x%p\n", p); + + validate_result(s, 1); + kmem_cache_destroy(s); +} + +static void __init test_clobber_50th_byte(void) +{ + struct kmem_cache *s = kmem_cache_create("TestSlub_50th_word_free", 64, 0, + SLAB_POISON, NULL); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kmem_cache_free(s, p); + p[50] = 0x9a; + pr_err("3. kmem_cache: Clobber 50th byte 0x9a->0x%p\n", p); + + validate_result(s, 1); + kmem_cache_destroy(s); +} + +static void __init test_clobber_redzone_free(void) +{ + struct kmem_cache *s = kmem_cache_create("TestSlub_RZ_free", 64, 0, + SLAB_RED_ZONE, NULL); + u8 *p = kmem_cache_alloc(s, GFP_KERNEL); + + kmem_cache_free(s, p); + p[64] = 0xab; + pr_err("4. kmem_cache: Clobber redzone 0xab->0x%p\n", p); + + validate_result(s, 1); + kmem_cache_destroy(s); +} + +static void __init resiliency_test(void) +{ + + BUILD_BUG_ON(KMALLOC_MIN_SIZE > 16 || KMALLOC_SHIFT_HIGH < 10); + + pr_err("SLUB resiliency testing\n"); + pr_err("-----------------------\n"); + pr_err("A. Corruption after allocation\n"); + + test_clobber_zone(); + + pr_err("\nB. Corruption after free\n"); + + test_next_pointer(); + test_first_word(); + test_clobber_50th_byte(); + test_clobber_redzone_free(); +} + + +static void __init selftest(void) +{ + resiliency_test(); +} + + +KSTM_MODULE_LOADERS(test_slub); +MODULE_LICENSE("GPL"); diff --git a/mm/slab.h b/mm/slab.h index 076582f58f68..5fc18d506b3b 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -215,6 +215,7 @@ DECLARE_STATIC_KEY_TRUE(slub_debug_enabled); DECLARE_STATIC_KEY_FALSE(slub_debug_enabled); #endif extern void print_tracking(struct kmem_cache *s, void *object); +long validate_slab_cache(struct kmem_cache *s, int *errors); #else static inline void print_tracking(struct kmem_cache *s, void *object) { diff --git a/mm/slub.c b/mm/slub.c index e26c274b4657..c00e2b263e03 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -4612,7 +4612,8 @@ static int count_total(struct page *page) #endif #ifdef CONFIG_SLUB_DEBUG -static void validate_slab(struct kmem_cache *s, struct page *page) +static void validate_slab(struct kmem_cache *s, struct page *page, + int *errors) { void *p; void *addr = page_address(page); @@ -4620,8 +4621,10 @@ static void validate_slab(struct kmem_cache *s, struct page *page) slab_lock(page); - if (!check_slab(s, page) || !on_freelist(s, page, NULL)) + if (!check_slab(s, page) || !on_freelist(s, page, NULL)) { + *errors += 1; goto unlock; + } /* Now we know that a valid freelist exists */ map = get_map(s, page); @@ -4629,8 +4632,10 @@ static void validate_slab(struct kmem_cache *s, struct page *page) u8 val = test_bit(__obj_to_index(s, addr, p), map) ? SLUB_RED_INACTIVE : SLUB_RED_ACTIVE; - if (!check_object(s, page, p, val)) + if (!check_object(s, page, p, val)) { + *errors += 1; break; + } } put_map(map); unlock: @@ -4638,7 +4643,7 @@ static void validate_slab(struct kmem_cache *s, struct page *page) } static int validate_slab_node(struct kmem_cache *s, - struct kmem_cache_node *n) + struct kmem_cache_node *n, int *errors) { unsigned long count = 0; struct page *page; @@ -4647,30 +4652,34 @@ static int validate_slab_node(struct kmem_cache *s, spin_lock_irqsave(&n->list_lock, flags); list_for_each_entry(page, &n->partial, slab_list) { - validate_slab(s, page); + validate_slab(s, page, errors); count++; } - if (count != n->nr_partial) + if (count != n->nr_partial) { pr_err("SLUB %s: %ld partial slabs counted but counter=%ld\n", s->name, count, n->nr_partial); + *errors += 1; + } if (!(s->flags & SLAB_STORE_USER)) goto out; list_for_each_entry(page, &n->full, slab_list) { - validate_slab(s, page); + validate_slab(s, page, errors); count++; } - if (count != atomic_long_read(&n->nr_slabs)) + if (count != atomic_long_read(&n->nr_slabs)) { pr_err("SLUB: %s %ld slabs counted but counter=%ld\n", s->name, count, atomic_long_read(&n->nr_slabs)); + *errors += 1; + } out: spin_unlock_irqrestore(&n->list_lock, flags); return count; } -static long validate_slab_cache(struct kmem_cache *s) +long validate_slab_cache(struct kmem_cache *s, int *errors) { int node; unsigned long count = 0; @@ -4678,10 +4687,12 @@ static long validate_slab_cache(struct kmem_cache *s) flush_all(s); for_each_kmem_cache_node(s, node, n) - count += validate_slab_node(s, n); + count += validate_slab_node(s, n, errors); return count; } +EXPORT_SYMBOL(validate_slab_cache); + /* * Generate lists of code addresses where slabcache objects are allocated * and freed. @@ -5336,9 +5347,10 @@ static ssize_t validate_store(struct kmem_cache *s, const char *buf, size_t length) { int ret = -EINVAL; + int errors = 0; if (buf[0] == '1') { - ret = validate_slab_cache(s); + ret = validate_slab_cache(s, &errors); if (ret >= 0) ret = length; } diff --git a/tools/testing/selftests/lib/Makefile b/tools/testing/selftests/lib/Makefile index a105f094676e..f168313b7949 100644 --- a/tools/testing/selftests/lib/Makefile +++ b/tools/testing/selftests/lib/Makefile @@ -4,6 +4,6 @@ # No binaries, but make sure arg-less "make" doesn't trigger "run_tests" all: -TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh strscpy.sh +TEST_PROGS := printf.sh bitmap.sh prime_numbers.sh strscpy.sh slub.sh include ../lib.mk diff --git a/tools/testing/selftests/lib/config b/tools/testing/selftests/lib/config index b80ee3f6e265..4190863032e7 100644 --- a/tools/testing/selftests/lib/config +++ b/tools/testing/selftests/lib/config @@ -3,3 +3,4 @@ CONFIG_TEST_BITMAP=m CONFIG_PRIME_NUMBERS=m CONFIG_TEST_STRSCPY=m CONFIG_TEST_BITOPS=m +CONFIG_TEST_SLUB=m \ No newline at end of file diff --git a/tools/testing/selftests/lib/slub.sh b/tools/testing/selftests/lib/slub.sh new file mode 100755 index 000000000000..8b5757702910 --- /dev/null +++ b/tools/testing/selftests/lib/slub.sh @@ -0,0 +1,3 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0+ +$(dirname $0)/../kselftest/module.sh "slub" test_slub -- 2.17.1

3 years, 2 months

4
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[PATCH v2 1/2] kvm/kvm_util: add _vm_ioctl

by Emanuele Giuseppe Esposito

As in kvm_ioctl and _kvm_ioctl, add the respective _vm_ioctl for vm_ioctl. _vm_ioctl invokes an ioctl using the vm fd, leaving the caller to test the result. Signed-off-by: Emanuele Giuseppe Esposito <eesposit(a)redhat.com> --- tools/testing/selftests/kvm/include/kvm_util.h | 1 + tools/testing/selftests/kvm/lib/kvm_util.c | 7 ++++++- 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/kvm/include/kvm_util.h b/tools/testing/selftests/kvm/include/kvm_util.h index 2d7eb6989e83..d53a5f7cad61 100644 --- a/tools/testing/selftests/kvm/include/kvm_util.h +++ b/tools/testing/selftests/kvm/include/kvm_util.h @@ -133,6 +133,7 @@ void vcpu_ioctl(struct kvm_vm *vm, uint32_t vcpuid, unsigned long ioctl, int _vcpu_ioctl(struct kvm_vm *vm, uint32_t vcpuid, unsigned long ioctl, void *arg); void vm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg); +int _vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg); void kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg); int _kvm_ioctl(struct kvm_vm *vm, unsigned long ioctl, void *arg); void vm_mem_region_set_flags(struct kvm_vm *vm, uint32_t slot, uint32_t flags); diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c index e5fbf16f725b..b8849a1aca79 100644 --- a/tools/testing/selftests/kvm/lib/kvm_util.c +++ b/tools/testing/selftests/kvm/lib/kvm_util.c @@ -1697,11 +1697,16 @@ void vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg) { int ret; - ret = ioctl(vm->fd, cmd, arg); + ret = _vm_ioctl(vm, cmd, arg); TEST_ASSERT(ret == 0, "vm ioctl %lu failed, rc: %i errno: %i (%s)", cmd, ret, errno, strerror(errno)); } +int _vm_ioctl(struct kvm_vm *vm, unsigned long cmd, void *arg) +{ + return ioctl(vm->fd, cmd, arg); +} + /* * KVM system ioctl * -- 2.29.2

3 years, 2 months

3
6
0 0

[PATCH] selftests/kvm: add get_msr_index_features

by Emanuele Giuseppe Esposito

Test the KVM_GET_MSR_FEATURE_INDEX_LIST and KVM_GET_MSR_INDEX_LIST ioctls. Signed-off-by: Emanuele Giuseppe Esposito <eesposit(a)redhat.com> --- tools/testing/selftests/kvm/.gitignore | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../kvm/x86_64/get_msr_index_features.c | 124 ++++++++++++++++++ 3 files changed, 126 insertions(+) create mode 100644 tools/testing/selftests/kvm/x86_64/get_msr_index_features.c diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore index 32b87cc77c8e..d99f3969d371 100644 --- a/tools/testing/selftests/kvm/.gitignore +++ b/tools/testing/selftests/kvm/.gitignore @@ -5,6 +5,7 @@ /s390x/resets /s390x/sync_regs_test /x86_64/cr4_cpuid_sync_test +/x86_64/get_msr_index_features /x86_64/debug_regs /x86_64/evmcs_test /x86_64/get_cpuid_test diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index a6d61f451f88..c748b9650e28 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -39,6 +39,7 @@ LIBKVM_aarch64 = lib/aarch64/processor.c lib/aarch64/ucall.c LIBKVM_s390x = lib/s390x/processor.c lib/s390x/ucall.c lib/s390x/diag318_test_handler.c TEST_GEN_PROGS_x86_64 = x86_64/cr4_cpuid_sync_test +TEST_GEN_PROGS_x86_64 += x86_64/get_msr_index_features TEST_GEN_PROGS_x86_64 += x86_64/evmcs_test TEST_GEN_PROGS_x86_64 += x86_64/get_cpuid_test TEST_GEN_PROGS_x86_64 += x86_64/hyperv_cpuid diff --git a/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c b/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c new file mode 100644 index 000000000000..ad9972d99dfa --- /dev/null +++ b/tools/testing/selftests/kvm/x86_64/get_msr_index_features.c @@ -0,0 +1,124 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Test that KVM_GET_MSR_INDEX_LIST and + * KVM_GET_MSR_FEATURE_INDEX_LIST work as intended + * + * Copyright (C) 2020, Red Hat, Inc. + */ +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <sys/ioctl.h> + +#include "test_util.h" +#include "kvm_util.h" +#include "processor.h" +#include "../lib/kvm_util_internal.h" + +static int kvm_num_index_msrs(int kvm_fd, int nmsrs) +{ + struct kvm_msr_list *list; + int r; + + list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0])); + list->nmsrs = nmsrs; + r = ioctl(kvm_fd, KVM_GET_MSR_INDEX_LIST, list); + TEST_ASSERT(r == -1 && errno == E2BIG, + "Unexpected result from KVM_GET_MSR_INDEX_LIST probe, r: %i", + r); + + r = list->nmsrs; + free(list); + return r; +} + +static void test_get_msr_index(void) +{ + int old_res, res, kvm_fd; + + kvm_fd = open(KVM_DEV_PATH, O_RDONLY); + if (kvm_fd < 0) + exit(KSFT_SKIP); + + old_res = kvm_num_index_msrs(kvm_fd, 0); + TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0"); + + if (old_res != 1) { + res = kvm_num_index_msrs(kvm_fd, 1); + TEST_ASSERT(res > 1, "Expecting nmsrs to be > 1"); + TEST_ASSERT(res == old_res, "Expecting nmsrs to be identical"); + } + + close(kvm_fd); +} + +static int kvm_num_feature_msrs(int kvm_fd, int nmsrs) +{ + struct kvm_msr_list *list; + int r; + + list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0])); + list->nmsrs = nmsrs; + r = ioctl(kvm_fd, KVM_GET_MSR_FEATURE_INDEX_LIST, list); + TEST_ASSERT(r == -1 && errno == E2BIG, + "Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST probe, r: %i", + r); + + r = list->nmsrs; + free(list); + return r; +} + +struct kvm_msr_list *kvm_get_msr_feature_list(int kvm_fd, int nmsrs) +{ + struct kvm_msr_list *list; + int r; + + list = malloc(sizeof(*list) + nmsrs * sizeof(list->indices[0])); + list->nmsrs = nmsrs; + r = ioctl(kvm_fd, KVM_GET_MSR_FEATURE_INDEX_LIST, list); + + TEST_ASSERT(r == 0, + "Unexpected result from KVM_GET_MSR_FEATURE_INDEX_LIST, r: %i", + r); + + return list; +} + +static void test_get_msr_feature(void) +{ + int res, old_res, i, kvm_fd; + struct kvm_msr_list *feature_list; + + kvm_fd = open(KVM_DEV_PATH, O_RDONLY); + if (kvm_fd < 0) + exit(KSFT_SKIP); + + old_res = kvm_num_feature_msrs(kvm_fd, 0); + TEST_ASSERT(old_res != 0, "Expecting nmsrs to be > 0"); + + if (old_res != 1) { + res = kvm_num_feature_msrs(kvm_fd, 1); + TEST_ASSERT(res > 1, "Expecting nmsrs to be > 1"); + TEST_ASSERT(res == old_res, "Expecting nmsrs to be identical"); + } + + feature_list = kvm_get_msr_feature_list(kvm_fd, old_res); + TEST_ASSERT(old_res == feature_list->nmsrs, + "Unmatching number of msr indexes"); + + for (i = 0; i < feature_list->nmsrs; i++) + kvm_get_feature_msr(feature_list->indices[i]); + + free(feature_list); + close(kvm_fd); +} + +int main(int argc, char *argv[]) +{ + if (kvm_check_cap(KVM_CAP_GET_MSR_FEATURES)) + test_get_msr_feature(); + + test_get_msr_index(); +} -- 2.29.2

3 years, 2 months

4
7
0 0

[PATCH] selftests/sgx: improve error detection and messages

by Dave Hansen

From: Dave Hansen <dave.hansen(a)linux.intel.com> The SGX device file (/dev/sgx_enclave) is unusual in that it requires execute permissions. It has to be both "chmod +x" *and* be on a filesystem without 'noexec'. In the future, udev and systemd should get updates to set up systems automatically. But, for now, nobody's systems do this automatically, and everybody gets error messages like this when running ./test_sgx: 0x0000000000000000 0x0000000000002000 0x03 0x0000000000002000 0x0000000000001000 0x05 0x0000000000003000 0x0000000000003000 0x03 mmap() failed, errno=1. That isn't very user friendly, even for forgetful kernel developers. Further, the test case is rather haphazard about its use of fprintf() versus perror(). Improve the error messages. Use perror() where possible. Lastly, do some sanity checks on opening and mmap()ing the device file so that we can get a decent error message out to the user. Now, if your user doesn't have permission, you'll get the following: $ ls -l /dev/sgx_enclave crw------- 1 root root 10, 126 Mar 18 11:29 /dev/sgx_enclave $ ./test_sgx Unable to open /dev/sgx_enclave: Permission denied If you then 'chown dave:dave /dev/sgx_enclave' (or whatever), but you leave execute permissions off, you'll get: $ ls -l /dev/sgx_enclave crw------- 1 dave dave 10, 126 Mar 18 11:29 /dev/sgx_enclave $ ./test_sgx no execute permissions on device file If you fix that with "chmod ug+x /dev/sgx" but you leave /dev as noexec, you'll get this: $ mount | grep "/dev .*noexec" udev on /dev type devtmpfs (rw,nosuid,noexec,...) $ ./test_sgx ERROR: mmap for exec: Operation not permitted mmap() succeeded for PROT_READ, but failed for PROT_EXEC check that user has execute permissions on /dev/sgx_enclave and that /dev does not have noexec set: 'mount | grep "/dev .*noexec"' That can be fixed with: mount -o remount,noexec /devESC Hopefully, the combination of better error messages and the search engines indexing this message will help people fix their systems until we do this properly. Signed-off-by: Dave Hansen <dave.hansen(a)linux.intel.com> Cc: Jarkko Sakkinen <jarkko(a)kernel.org> Cc: Shuah Khan <shuah(a)kernel.org> Cc: Borislav Petkov <bp(a)alien8.de> Cc: x86(a)kernel.org Cc: linux-sgx(a)vger.kernel.org Cc: linux-kselftest(a)vger.kernel.org --- b/tools/testing/selftests/sgx/load.c | 66 +++++++++++++++++++++++++++-------- b/tools/testing/selftests/sgx/main.c | 2 - 2 files changed, 53 insertions(+), 15 deletions(-) diff -puN tools/testing/selftests/sgx/load.c~sgx-selftest-err-rework tools/testing/selftests/sgx/load.c --- a/tools/testing/selftests/sgx/load.c~sgx-selftest-err-rework 2021-03-18 12:18:38.649828215 -0700 +++ b/tools/testing/selftests/sgx/load.c 2021-03-18 12:40:46.388824904 -0700 @@ -45,19 +45,19 @@ static bool encl_map_bin(const char *pat fd = open(path, O_RDONLY); if (fd == -1) { - perror("open()"); + perror("enclave executable open()"); return false; } ret = stat(path, &sb); if (ret) { - perror("stat()"); + perror("enclave executable stat()"); goto err; } bin = mmap(NULL, sb.st_size, PROT_READ, MAP_PRIVATE, fd, 0); if (bin == MAP_FAILED) { - perror("mmap()"); + perror("enclave executable mmap()"); goto err; } @@ -90,8 +90,7 @@ static bool encl_ioc_create(struct encl ioc.src = (unsigned long)secs; rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_CREATE, &ioc); if (rc) { - fprintf(stderr, "SGX_IOC_ENCLAVE_CREATE failed: errno=%d\n", - errno); + perror("SGX_IOC_ENCLAVE_CREATE failed"); munmap((void *)secs->base, encl->encl_size); return false; } @@ -116,31 +115,69 @@ static bool encl_ioc_add_pages(struct en rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_ADD_PAGES, &ioc); if (rc < 0) { - fprintf(stderr, "SGX_IOC_ENCLAVE_ADD_PAGES failed: errno=%d.\n", - errno); + perror("SGX_IOC_ENCLAVE_ADD_PAGES failed"); return false; } return true; } + + bool encl_load(const char *path, struct encl *encl) { + const char device_path[] = "/dev/sgx_enclave"; Elf64_Phdr *phdr_tbl; off_t src_offset; Elf64_Ehdr *ehdr; + struct stat sb; + void *ptr; int i, j; int ret; + int fd = -1; memset(encl, 0, sizeof(*encl)); - ret = open("/dev/sgx_enclave", O_RDWR); - if (ret < 0) { - fprintf(stderr, "Unable to open /dev/sgx_enclave\n"); + fd = open(device_path, O_RDWR); + if (fd < 0) { + perror("Unable to open /dev/sgx_enclave"); + goto err; + } + + ret = stat(device_path, &sb); + if (ret) { + perror("device file stat()"); + goto err; + } + + /* + * This just checks if the /dev file has these permission + * bits set. It does not check that the current user is + * the owner or in the owning group. + */ + if (!(sb.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH))) { + fprintf(stderr, "no execute permissions on device file\n"); + goto err; + } + + ptr = mmap(NULL, PAGE_SIZE, PROT_READ, MAP_SHARED, fd, 0); + if (ptr == (void *)-1) { + perror("mmap for read"); + goto err; + } + munmap(ptr, PAGE_SIZE); + + ptr = mmap(NULL, PAGE_SIZE, PROT_EXEC, MAP_SHARED, fd, 0); + if (ptr == (void *)-1) { + perror("ERROR: mmap for exec"); + fprintf(stderr, "mmap() succeeded for PROT_READ, but failed for PROT_EXEC\n"); + fprintf(stderr, "check that user has execute permissions on %s and\n", device_path); + fprintf(stderr, "that /dev does not have noexec set: 'mount | grep \"/dev .*noexec\"'\n"); goto err; } + munmap(ptr, PAGE_SIZE); - encl->fd = ret; + encl->fd = fd; if (!encl_map_bin(path, encl)) goto err; @@ -217,6 +254,8 @@ bool encl_load(const char *path, struct return true; err: + if (fd != -1) + close(fd); encl_delete(encl); return false; } @@ -229,7 +268,7 @@ static bool encl_map_area(struct encl *e area = mmap(NULL, encl_size * 2, PROT_NONE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0); if (area == MAP_FAILED) { - perror("mmap"); + perror("reservation mmap()"); return false; } @@ -268,8 +307,7 @@ bool encl_build(struct encl *encl) ioc.sigstruct = (uint64_t)&encl->sigstruct; ret = ioctl(encl->fd, SGX_IOC_ENCLAVE_INIT, &ioc); if (ret) { - fprintf(stderr, "SGX_IOC_ENCLAVE_INIT failed: errno=%d\n", - errno); + perror("SGX_IOC_ENCLAVE_INIT failed"); return false; } diff -puN tools/testing/selftests/sgx/main.c~sgx-selftest-err-rework tools/testing/selftests/sgx/main.c --- a/tools/testing/selftests/sgx/main.c~sgx-selftest-err-rework 2021-03-18 12:18:38.652828215 -0700 +++ b/tools/testing/selftests/sgx/main.c 2021-03-18 12:18:38.657828215 -0700 @@ -195,7 +195,7 @@ int main(int argc, char *argv[], char *e addr = mmap((void *)encl.encl_base + seg->offset, seg->size, seg->prot, MAP_SHARED | MAP_FIXED, encl.fd, 0); if (addr == MAP_FAILED) { - fprintf(stderr, "mmap() failed, errno=%d.\n", errno); + perror("mmap() segment failed"); exit(KSFT_FAIL); } } _

3 years, 2 months

2
1
0 0

[PATCH v4 1/2] mm: huge_memory: a new debugfs interface for splitting THP tests.

by Zi Yan

From: Zi Yan <ziy(a)nvidia.com> We did not have a direct user interface of splitting the compound page backing a THP and there is no need unless we want to expose the THP implementation details to users. Make <debugfs>/split_huge_pages accept a new command to do that. By writing "<pid>,<vaddr_start>,<vaddr_end>" to <debugfs>/split_huge_pages, THPs within the given virtual address range from the process with the given pid are split. It is used to test split_huge_page function. In addition, a selftest program is added to tools/testing/selftests/vm to utilize the interface by splitting PMD THPs and PTE-mapped THPs. This does not change the old behavior, i.e., writing 1 to the interface to split all THPs in the system. Changelog: >From v3: 1. Factored out split huge pages in the given pid code to a separate function. 2. Added the missing put_page for not split pages. 3. pr_debug -> pr_info, make reading results simpler. >From v2: 1. Reused existing <debugfs>/split_huge_pages interface. (suggested by Yang Shi) >From v1: 1. Removed unnecessary calling to vma_migratable, spotted by kernel test robot <lkp(a)intel.com>. 2. Dropped the use of find_mm_struct and code it directly, since there is no need for the permission check in that function and the function is only available when migration is on. 3. Added some comments in the selftest program to clarify how PTE-mapped THPs are formed. Signed-off-by: Zi Yan <ziy(a)nvidia.com> --- mm/huge_memory.c | 136 +++++++- tools/testing/selftests/vm/.gitignore | 1 + tools/testing/selftests/vm/Makefile | 1 + .../selftests/vm/split_huge_page_test.c | 313 ++++++++++++++++++ 4 files changed, 444 insertions(+), 7 deletions(-) create mode 100644 tools/testing/selftests/vm/split_huge_page_test.c diff --git a/mm/huge_memory.c b/mm/huge_memory.c index bff92dea5ab3..3bfee54e2cd0 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -7,6 +7,7 @@ #include <linux/mm.h> #include <linux/sched.h> +#include <linux/sched/mm.h> #include <linux/sched/coredump.h> #include <linux/sched/numa_balancing.h> #include <linux/highmem.h> @@ -2922,16 +2923,14 @@ static struct shrinker deferred_split_shrinker = { }; #ifdef CONFIG_DEBUG_FS -static int split_huge_pages_set(void *data, u64 val) +static void split_huge_pages_all(void) { struct zone *zone; struct page *page; unsigned long pfn, max_zone_pfn; unsigned long total = 0, split = 0; - if (val != 1) - return -EINVAL; - + pr_info("Split all THPs\n"); for_each_populated_zone(zone) { max_zone_pfn = zone_end_pfn(zone); for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) { @@ -2959,11 +2958,134 @@ static int split_huge_pages_set(void *data, u64 val) } pr_info("%lu of %lu THP split\n", split, total); +} - return 0; +static int split_huge_pages_pid(int pid, unsigned long vaddr_start, + unsigned long vaddr_end) +{ + int ret = 0; + struct task_struct *task; + struct mm_struct *mm; + unsigned long total = 0, split = 0; + unsigned long addr; + + vaddr_start &= PAGE_MASK; + vaddr_end &= PAGE_MASK; + + /* Find the task_struct from pid */ + rcu_read_lock(); + task = find_task_by_vpid(pid); + if (!task) { + rcu_read_unlock(); + ret = -ESRCH; + goto out; + } + get_task_struct(task); + rcu_read_unlock(); + + /* Find the mm_struct */ + mm = get_task_mm(task); + put_task_struct(task); + + if (!mm) { + ret = -EINVAL; + goto out; + } + + pr_info("Split huge pages in pid: %d, vaddr: [0x%lx - 0x%lx]\n", + pid, vaddr_start, vaddr_end); + + mmap_read_lock(mm); + /* + * always increase addr by PAGE_SIZE, since we could have a PTE page + * table filled with PTE-mapped THPs, each of which is distinct. + */ + for (addr = vaddr_start; addr < vaddr_end; addr += PAGE_SIZE) { + struct vm_area_struct *vma = find_vma(mm, addr); + unsigned int follflags; + struct page *page; + + if (!vma || addr < vma->vm_start) + break; + + /* FOLL_DUMP to ignore special (like zero) pages */ + follflags = FOLL_GET | FOLL_DUMP; + page = follow_page(vma, addr, follflags); + + if (IS_ERR(page)) + break; + if (!page) + break; + + if (!is_transparent_hugepage(page)) + goto next; + + total++; + if (!can_split_huge_page(compound_head(page), NULL)) + goto next; + + if (!trylock_page(page)) + goto next; + + if (!split_huge_page(page)) + split++; + + unlock_page(page); +next: + put_page(page); + } + mmap_read_unlock(mm); + mmput(mm); + + pr_info("%lu of %lu THP split\n", split, total); + +out: + return ret; } -DEFINE_DEBUGFS_ATTRIBUTE(split_huge_pages_fops, NULL, split_huge_pages_set, - "%llu\n"); + +static ssize_t split_huge_pages_write(struct file *file, const char __user *buf, + size_t count, loff_t *ppops) +{ + static DEFINE_MUTEX(mutex); + ssize_t ret; + char input_buf[80]; /* hold pid, start_vaddr, end_vaddr */ + int pid; + unsigned long vaddr_start, vaddr_end; + + ret = mutex_lock_interruptible(&mutex); + if (ret) + return ret; + + ret = -EFAULT; + + memset(input_buf, 0, 80); + if (copy_from_user(input_buf, buf, min_t(size_t, count, 80))) + goto out; + + input_buf[79] = '\0'; + ret = sscanf(input_buf, "%d,0x%lx,0x%lx", &pid, &vaddr_start, &vaddr_end); + if (ret == 1 && pid == 1) { + split_huge_pages_all(); + ret = strlen(input_buf); + goto out; + } else if (ret != 3) { + ret = -EINVAL; + goto out; + } + + if (!split_huge_pages_pid(pid, vaddr_start, vaddr_end)) + ret = strlen(input_buf); +out: + mutex_unlock(&mutex); + return ret; + +} + +static const struct file_operations split_huge_pages_fops = { + .owner = THIS_MODULE, + .write = split_huge_pages_write, + .llseek = no_llseek, +}; static int __init split_huge_pages_debugfs(void) { diff --git a/tools/testing/selftests/vm/.gitignore b/tools/testing/selftests/vm/.gitignore index 9a35c3f6a557..1f651e85ed60 100644 --- a/tools/testing/selftests/vm/.gitignore +++ b/tools/testing/selftests/vm/.gitignore @@ -22,3 +22,4 @@ map_fixed_noreplace write_to_hugetlbfs hmm-tests local_config.* +split_huge_page_test diff --git a/tools/testing/selftests/vm/Makefile b/tools/testing/selftests/vm/Makefile index d42115e4284d..4cbc91d6869f 100644 --- a/tools/testing/selftests/vm/Makefile +++ b/tools/testing/selftests/vm/Makefile @@ -42,6 +42,7 @@ TEST_GEN_FILES += on-fault-limit TEST_GEN_FILES += thuge-gen TEST_GEN_FILES += transhuge-stress TEST_GEN_FILES += userfaultfd +TEST_GEN_FILES += split_huge_page_test ifeq ($(MACHINE),x86_64) CAN_BUILD_I386 := $(shell ./../x86/check_cc.sh $(CC) ../x86/trivial_32bit_program.c -m32) diff --git a/tools/testing/selftests/vm/split_huge_page_test.c b/tools/testing/selftests/vm/split_huge_page_test.c new file mode 100644 index 000000000000..9f33ddbb3182 --- /dev/null +++ b/tools/testing/selftests/vm/split_huge_page_test.c @@ -0,0 +1,313 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * A test of splitting PMD THPs and PTE-mapped THPs from a specified virtual + * address range in a process via <debugfs>/split_huge_pages interface. + */ + +#define _GNU_SOURCE +#include <stdio.h> +#include <stdlib.h> +#include <unistd.h> +#include <inttypes.h> +#include <string.h> +#include <fcntl.h> +#include <sys/mman.h> +#include <malloc.h> +#include <stdbool.h> + +uint64_t pagesize; +unsigned int pageshift; +uint64_t pmd_pagesize; + +#define PMD_SIZE_PATH "/sys/kernel/mm/transparent_hugepage/hpage_pmd_size" +#define SPLIT_DEBUGFS "/sys/kernel/debug/split_huge_pages" +#define SMAP_PATH "/proc/self/smaps" +#define INPUT_MAX 80 + +#define PFN_MASK ((1UL<<55)-1) +#define KPF_THP (1UL<<22) + +int is_backed_by_thp(char *vaddr, int pagemap_file, int kpageflags_file) +{ + uint64_t paddr; + uint64_t page_flags; + + if (pagemap_file) { + pread(pagemap_file, &paddr, sizeof(paddr), + ((long)vaddr >> pageshift) * sizeof(paddr)); + + if (kpageflags_file) { + pread(kpageflags_file, &page_flags, sizeof(page_flags), + (paddr & PFN_MASK) * sizeof(page_flags)); + + return !!(page_flags & KPF_THP); + } + } + return 0; +} + + +static uint64_t read_pmd_pagesize(void) +{ + int fd; + char buf[20]; + ssize_t num_read; + + fd = open(PMD_SIZE_PATH, O_RDONLY); + if (fd == -1) { + perror("Open hpage_pmd_size failed"); + exit(EXIT_FAILURE); + } + num_read = read(fd, buf, 19); + if (num_read < 1) { + close(fd); + perror("Read hpage_pmd_size failed"); + exit(EXIT_FAILURE); + } + buf[num_read] = '\0'; + close(fd); + + return strtoul(buf, NULL, 10); +} + +static int write_file(const char *path, const char *buf, size_t buflen) +{ + int fd; + ssize_t numwritten; + + fd = open(path, O_WRONLY); + if (fd == -1) + return 0; + + numwritten = write(fd, buf, buflen - 1); + close(fd); + if (numwritten < 1) + return 0; + + return (unsigned int) numwritten; +} + +static void write_debugfs(int pid, uint64_t vaddr_start, uint64_t vaddr_end) +{ + char input[INPUT_MAX]; + int ret; + + ret = snprintf(input, INPUT_MAX, "%d,0x%lx,0x%lx", pid, vaddr_start, + vaddr_end); + if (ret >= INPUT_MAX) { + printf("%s: Debugfs input is too long\n", __func__); + exit(EXIT_FAILURE); + } + + if (!write_file(SPLIT_DEBUGFS, input, ret + 1)) { + perror(SPLIT_DEBUGFS); + exit(EXIT_FAILURE); + } +} + +#define MAX_LINE_LENGTH 500 + +static bool check_for_pattern(FILE *fp, const char *pattern, char *buf) +{ + while (fgets(buf, MAX_LINE_LENGTH, fp) != NULL) { + if (!strncmp(buf, pattern, strlen(pattern))) + return true; + } + return false; +} + +static uint64_t check_huge(void *addr) +{ + uint64_t thp = 0; + int ret; + FILE *fp; + char buffer[MAX_LINE_LENGTH]; + char addr_pattern[MAX_LINE_LENGTH]; + + ret = snprintf(addr_pattern, MAX_LINE_LENGTH, "%08lx-", + (unsigned long) addr); + if (ret >= MAX_LINE_LENGTH) { + printf("%s: Pattern is too long\n", __func__); + exit(EXIT_FAILURE); + } + + + fp = fopen(SMAP_PATH, "r"); + if (!fp) { + printf("%s: Failed to open file %s\n", __func__, SMAP_PATH); + exit(EXIT_FAILURE); + } + if (!check_for_pattern(fp, addr_pattern, buffer)) + goto err_out; + + /* + * Fetch the AnonHugePages: in the same block and check the number of + * hugepages. + */ + if (!check_for_pattern(fp, "AnonHugePages:", buffer)) + goto err_out; + + if (sscanf(buffer, "AnonHugePages:%10ld kB", &thp) != 1) { + printf("Reading smap error\n"); + exit(EXIT_FAILURE); + } + +err_out: + fclose(fp); + return thp; +} + +void split_pmd_thp(void) +{ + char *one_page; + size_t len = 4 * pmd_pagesize; + uint64_t thp_size; + size_t i; + + one_page = memalign(pmd_pagesize, len); + + madvise(one_page, len, MADV_HUGEPAGE); + + for (i = 0; i < len; i++) + one_page[i] = (char)i; + + thp_size = check_huge(one_page); + if (!thp_size) { + printf("No THP is allocatd"); + exit(EXIT_FAILURE); + } + + /* split all THPs */ + write_debugfs(getpid(), (uint64_t)one_page, (uint64_t)one_page + len); + + for (i = 0; i < len; i++) + if (one_page[i] != (char)i) { + printf("%ld byte corrupted\n", i); + exit(EXIT_FAILURE); + } + + + thp_size = check_huge(one_page); + if (thp_size) { + printf("Still %ld kB AnonHugePages not split\n", thp_size); + exit(EXIT_FAILURE); + } + + printf("Split huge pages successful\n"); + free(one_page); +} + +void split_pte_mapped_thp(void) +{ + char *one_page, *pte_mapped, *pte_mapped2; + size_t len = 4 * pmd_pagesize; + uint64_t thp_size; + size_t i; + const char *pagemap_template = "/proc/%d/pagemap"; + const char *kpageflags_proc = "/proc/kpageflags"; + char pagemap_proc[255]; + int pagemap_fd; + int kpageflags_fd; + + if (snprintf(pagemap_proc, 255, pagemap_template, getpid()) < 0) { + perror("get pagemap proc error"); + exit(EXIT_FAILURE); + } + pagemap_fd = open(pagemap_proc, O_RDONLY); + + if (pagemap_fd == -1) { + perror("read pagemap:"); + exit(EXIT_FAILURE); + } + + kpageflags_fd = open(kpageflags_proc, O_RDONLY); + + if (kpageflags_fd == -1) { + perror("read kpageflags:"); + exit(EXIT_FAILURE); + } + + one_page = mmap((void *)(1UL << 30), len, PROT_READ | PROT_WRITE, + MAP_ANONYMOUS | MAP_PRIVATE, -1, 0); + + madvise(one_page, len, MADV_HUGEPAGE); + + for (i = 0; i < len; i++) + one_page[i] = (char)i; + + thp_size = check_huge(one_page); + if (!thp_size) { + printf("No THP is allocatd"); + exit(EXIT_FAILURE); + } + + /* remap the first pagesize of first THP */ + pte_mapped = mremap(one_page, pagesize, pagesize, MREMAP_MAYMOVE); + + /* remap the Nth pagesize of Nth THP */ + for (i = 1; i < 4; i++) { + pte_mapped2 = mremap(one_page + pmd_pagesize * i + pagesize * i, + pagesize, pagesize, + MREMAP_MAYMOVE|MREMAP_FIXED, + pte_mapped + pagesize * i); + if (pte_mapped2 == (char *)-1) { + perror("mremap failed"); + exit(EXIT_FAILURE); + } + } + + /* smap does not show THPs after mremap, use kpageflags instead */ + thp_size = 0; + for (i = 0; i < pagesize * 4; i++) + if (i % pagesize == 0 && + is_backed_by_thp(&pte_mapped[i], pagemap_fd, kpageflags_fd)) + thp_size++; + + if (thp_size != 4) { + printf("Some THPs are missing during mremap\n"); + exit(EXIT_FAILURE); + } + + /* split all remapped THPs */ + write_debugfs(getpid(), (uint64_t)pte_mapped, + (uint64_t)pte_mapped + pagesize * 4); + + /* smap does not show THPs after mremap, use kpageflags instead */ + thp_size = 0; + for (i = 0; i < pagesize * 4; i++) { + if (pte_mapped[i] != (char)i) { + printf("%ld byte corrupted\n", i); + exit(EXIT_FAILURE); + } + if (i % pagesize == 0 && + is_backed_by_thp(&pte_mapped[i], pagemap_fd, kpageflags_fd)) + thp_size++; + } + + if (thp_size) { + printf("Still %ld THPs not split\n", thp_size); + exit(EXIT_FAILURE); + } + + printf("Split PTE-mapped huge pages successful\n"); + munmap(one_page, len); + close(pagemap_fd); + close(kpageflags_fd); +} + +int main(int argc, char **argv) +{ + if (geteuid() != 0) { + printf("Please run the benchmark as root\n"); + exit(EXIT_FAILURE); + } + + pagesize = getpagesize(); + pageshift = ffs(pagesize) - 1; + pmd_pagesize = read_pmd_pagesize(); + + split_pmd_thp(); + split_pte_mapped_thp(); + + return 0; +} -- 2.30.1

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Linux-kselftest-mirror March 2021