Add a kunit test to verify the preserve/unpreserve and restore of pages and folios by mocking the kho kunit restore stubs.
Signed-off-by: Samiullah Khawaja <[email protected]> --- kernel/liveupdate/Kconfig | 10 ++ kernel/liveupdate/Makefile | 1 + kernel/liveupdate/kexec_handover_test.c | 130 ++++++++++++++++++++++++ 3 files changed, 141 insertions(+) create mode 100644 kernel/liveupdate/kexec_handover_test.c diff --git a/kernel/liveupdate/Kconfig b/kernel/liveupdate/Kconfig index c13af38ba23a..ffdfdc4080ef 100644 --- a/kernel/liveupdate/Kconfig +++ b/kernel/liveupdate/Kconfig @@ -49,6 +49,16 @@ config KEXEC_HANDOVER_ENABLE_DEFAULT The default behavior can still be overridden at boot time by passing 'kho=off'. +config KEXEC_HANDOVER_KUNIT_TEST + tristate "KUnit test for Kexec Handover (KHO)" + depends on KEXEC_HANDOVER && KUNIT + default KUNIT_ALL_TESTS + help + Enable Kunit tests for Kexec Handover to verify preservation and + unpreservation of memory using KHO API without triggering kexec. + + If unsure, say N. + config LIVEUPDATE bool "Live Update Orchestrator" depends on KEXEC_HANDOVER diff --git a/kernel/liveupdate/Makefile b/kernel/liveupdate/Makefile index d2f779cbe279..ed798b2401a8 100644 --- a/kernel/liveupdate/Makefile +++ b/kernel/liveupdate/Makefile @@ -9,5 +9,6 @@ luo-y := \ obj-$(CONFIG_KEXEC_HANDOVER) += kexec_handover.o obj-$(CONFIG_KEXEC_HANDOVER_DEBUG) += kexec_handover_debug.o obj-$(CONFIG_KEXEC_HANDOVER_DEBUGFS) += kexec_handover_debugfs.o +obj-$(CONFIG_KEXEC_HANDOVER_KUNIT_TEST) += kexec_handover_test.o obj-$(CONFIG_LIVEUPDATE) += luo.o diff --git a/kernel/liveupdate/kexec_handover_test.c b/kernel/liveupdate/kexec_handover_test.c new file mode 100644 index 000000000000..1113007f9ac5 --- /dev/null +++ b/kernel/liveupdate/kexec_handover_test.c @@ -0,0 +1,130 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2026, Google LLC + * Author: Samiullah Khawaja <[email protected]> + */ + +#include <kunit/test.h> +#include <kunit/static_stub.h> +#include <linux/kexec_handover.h> +#include <linux/gfp.h> +#include <linux/mm.h> + +static struct page *kho_test_restore_pages_mock(phys_addr_t phys, + unsigned long nr_pages) +{ + struct page *page = phys_to_page(phys); + + if (!kho_test_pages_preserved(phys, nr_pages)) + return NULL; + + kho_unpreserve_pages(page, nr_pages); + return page; +} + +static struct folio *kho_test_restore_folio_mock(phys_addr_t phys) +{ + struct folio *folio = page_folio(phys_to_page(phys)); + + if (!kho_test_pages_preserved(phys, (1 << folio_order(folio)))) + return NULL; + + kho_unpreserve_folio(folio); + return folio; +} + +static int kho_test_init(struct kunit *test) +{ + kunit_activate_static_stub(test, kho_restore_pages, + kho_test_restore_pages_mock); + kunit_activate_static_stub(test, kho_restore_folio, + kho_test_restore_folio_mock); + return 0; +} + +static void kho_test_alloc_preserve(struct kunit *test) +{ + void *mem; + + mem = kho_alloc_preserve(PAGE_SIZE); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, mem); + + /* Verify if memory is preserved */ + KUNIT_EXPECT_TRUE(test, kho_test_pages_preserved(__pa(mem), 1)); + + kho_restore_free(mem); + + /* Memory should be unpreserved after restore_free */ + KUNIT_EXPECT_FALSE(test, kho_test_pages_preserved(__pa(mem), 1)); +} + +static void kho_test_preserve_pages(struct kunit *test) +{ + struct page *restored; + struct page *page; + int err; + + page = alloc_pages(GFP_KERNEL | __GFP_ZERO, 1); + KUNIT_ASSERT_NOT_NULL(test, page); + + /* Preserve and verify that pages are preserved */ + err = kho_preserve_pages(page, 2); + KUNIT_EXPECT_EQ(test, err, 0); + KUNIT_EXPECT_TRUE(test, + kho_test_pages_preserved(page_to_phys(page), 2)); + + restored = kho_restore_pages(page_to_phys(page), 2); + KUNIT_EXPECT_NOT_NULL(test, restored); + KUNIT_EXPECT_PTR_EQ(test, restored, page); + + /* Verify that the pages are not preserved */ + KUNIT_EXPECT_FALSE(test, kho_test_pages_preserved(page_to_phys(page), 2)); + + __free_pages(page, 1); +} + +static void kho_test_preserve_folio(struct kunit *test) +{ + struct folio *restored; + unsigned long nr_pages; + struct folio *folio; + int err; + + folio = folio_alloc(GFP_KERNEL | __GFP_ZERO, 1); + KUNIT_ASSERT_NOT_NULL(test, folio); + + nr_pages = 1 << folio_order(folio); + + /* Preserve and verify that folio is preserved */ + err = kho_preserve_folio(folio); + KUNIT_EXPECT_EQ(test, err, 0); + KUNIT_EXPECT_TRUE(test, kho_test_pages_preserved(PFN_PHYS(folio_pfn(folio)), nr_pages)); + + restored = kho_restore_folio(PFN_PHYS(folio_pfn(folio))); + KUNIT_EXPECT_NOT_NULL(test, restored); + KUNIT_EXPECT_PTR_EQ(test, restored, folio); + + /* Verify that the folio is not preserved */ + KUNIT_EXPECT_FALSE(test, kho_test_pages_preserved(PFN_PHYS(folio_pfn(folio)), nr_pages)); + + folio_put(folio); +} + +static struct kunit_case kho_test_cases[] = { + KUNIT_CASE(kho_test_alloc_preserve), + KUNIT_CASE(kho_test_preserve_pages), + KUNIT_CASE(kho_test_preserve_folio), + {} +}; + +static struct kunit_suite kho_test_suite = { + .name = "kho_test", + .init = kho_test_init, + .test_cases = kho_test_cases, +}; + +kunit_test_suite(kho_test_suite); + +MODULE_IMPORT_NS("EXPORTED_FOR_KUNIT_TESTING"); +MODULE_DESCRIPTION("KUnit tests for Kexec Handover"); +MODULE_LICENSE("GPL"); -- 2.54.0.563.g4f69b47b94-goog
