diff options
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | lib/Kconfig.debug | 21 | ||||
| -rw-r--r-- | lib/Makefile | 1 | ||||
| -rw-r--r-- | lib/test_kho.c | 305 | ||||
| -rw-r--r-- | tools/testing/selftests/kho/arm64.conf | 9 | ||||
| -rw-r--r-- | tools/testing/selftests/kho/init.c | 100 | ||||
| -rwxr-xr-x | tools/testing/selftests/kho/vmtest.sh | 183 | ||||
| -rw-r--r-- | tools/testing/selftests/kho/x86.conf | 7 |
8 files changed, 627 insertions, 0 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 87897a285bc1..d16d76f24c6e 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -13353,6 +13353,7 @@ F: Documentation/admin-guide/mm/kho.rst F: Documentation/core-api/kho/* F: include/linux/kexec_handover.h F: kernel/kexec_handover.c +F: tools/testing/selftests/kho/ KEYS-ENCRYPTED M: Mimi Zohar <zohar@linux.ibm.com> diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index ebe33181b6e6..4f82d38e3c45 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -3225,6 +3225,27 @@ config TEST_OBJPOOL If unsure, say N. +config TEST_KEXEC_HANDOVER + bool "Test for Kexec HandOver" + default n + depends on KEXEC_HANDOVER + help + This option enables test for Kexec HandOver (KHO). + The test consists of two parts: saving kernel data before kexec and + restoring the data after kexec and verifying that it was properly + handed over. This test module creates and saves data on the boot of + the first kernel and restores and verifies the data on the boot of + kexec'ed kernel. + + For detailed documentation about KHO, see Documentation/core-api/kho. + + To run the test run: + + tools/testing/selftests/kho/vmtest.sh -h + + If unsure, say N. + + config INT_POW_KUNIT_TEST tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS depends on KUNIT diff --git a/lib/Makefile b/lib/Makefile index 88d6228089a8..dadf0028b319 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -102,6 +102,7 @@ obj-$(CONFIG_TEST_HMM) += test_hmm.o obj-$(CONFIG_TEST_FREE_PAGES) += test_free_pages.o obj-$(CONFIG_TEST_REF_TRACKER) += test_ref_tracker.o obj-$(CONFIG_TEST_OBJPOOL) += test_objpool.o +obj-$(CONFIG_TEST_KEXEC_HANDOVER) += test_kho.o obj-$(CONFIG_TEST_FPU) += test_fpu.o test_fpu-y := test_fpu_glue.o test_fpu_impl.o diff --git a/lib/test_kho.c b/lib/test_kho.c new file mode 100644 index 000000000000..c2eb899c3b45 --- /dev/null +++ b/lib/test_kho.c @@ -0,0 +1,305 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Test module for KHO + * Copyright (c) 2025 Microsoft Corporation. + * + * Authors: + * Saurabh Sengar <ssengar@microsoft.com> + * Mike Rapoport <rppt@kernel.org> + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/mm.h> +#include <linux/gfp.h> +#include <linux/slab.h> +#include <linux/kexec.h> +#include <linux/libfdt.h> +#include <linux/module.h> +#include <linux/printk.h> +#include <linux/vmalloc.h> +#include <linux/kexec_handover.h> + +#include <net/checksum.h> + +#define KHO_TEST_MAGIC 0x4b484f21 /* KHO! */ +#define KHO_TEST_FDT "kho_test" +#define KHO_TEST_COMPAT "kho-test-v1" + +static long max_mem = (PAGE_SIZE << MAX_PAGE_ORDER) * 2; +module_param(max_mem, long, 0644); + +struct kho_test_state { + unsigned int nr_folios; + struct folio **folios; + struct folio *fdt; + __wsum csum; +}; + +static struct kho_test_state kho_test_state; + +static int kho_test_notifier(struct notifier_block *self, unsigned long cmd, + void *v) +{ + struct kho_test_state *state = &kho_test_state; + struct kho_serialization *ser = v; + int err = 0; + + switch (cmd) { + case KEXEC_KHO_ABORT: + return NOTIFY_DONE; + case KEXEC_KHO_FINALIZE: + /* Handled below */ + break; + default: + return NOTIFY_BAD; + } + + err |= kho_preserve_folio(state->fdt); + err |= kho_add_subtree(ser, KHO_TEST_FDT, folio_address(state->fdt)); + + return err ? NOTIFY_BAD : NOTIFY_DONE; +} + +static struct notifier_block kho_test_nb = { + .notifier_call = kho_test_notifier, +}; + +static int kho_test_save_data(struct kho_test_state *state, void *fdt) +{ + phys_addr_t *folios_info __free(kvfree) = NULL; + int err = 0; + + folios_info = kvmalloc_array(state->nr_folios, sizeof(*folios_info), + GFP_KERNEL); + if (!folios_info) + return -ENOMEM; + + for (int i = 0; i < state->nr_folios; i++) { + struct folio *folio = state->folios[i]; + unsigned int order = folio_order(folio); + + folios_info[i] = virt_to_phys(folio_address(folio)) | order; + + err = kho_preserve_folio(folio); + if (err) + return err; + } + + err |= fdt_begin_node(fdt, "data"); + err |= fdt_property(fdt, "nr_folios", &state->nr_folios, + sizeof(state->nr_folios)); + err |= fdt_property(fdt, "folios_info", folios_info, + state->nr_folios * sizeof(*folios_info)); + err |= fdt_property(fdt, "csum", &state->csum, sizeof(state->csum)); + err |= fdt_end_node(fdt); + + return err; +} + +static int kho_test_prepare_fdt(struct kho_test_state *state) +{ + const char compatible[] = KHO_TEST_COMPAT; + unsigned int magic = KHO_TEST_MAGIC; + ssize_t fdt_size; + int err = 0; + void *fdt; + + fdt_size = state->nr_folios * sizeof(phys_addr_t) + PAGE_SIZE; + state->fdt = folio_alloc(GFP_KERNEL, get_order(fdt_size)); + if (!state->fdt) + return -ENOMEM; + + fdt = folio_address(state->fdt); + + err |= fdt_create(fdt, fdt_size); + err |= fdt_finish_reservemap(fdt); + + err |= fdt_begin_node(fdt, ""); + err |= fdt_property(fdt, "compatible", compatible, sizeof(compatible)); + err |= fdt_property(fdt, "magic", &magic, sizeof(magic)); + err |= kho_test_save_data(state, fdt); + err |= fdt_end_node(fdt); + + err |= fdt_finish(fdt); + + if (err) + folio_put(state->fdt); + + return err; +} + +static int kho_test_generate_data(struct kho_test_state *state) +{ + size_t alloc_size = 0; + __wsum csum = 0; + + while (alloc_size < max_mem) { + int order = get_random_u32() % NR_PAGE_ORDERS; + struct folio *folio; + unsigned int size; + void *addr; + + /* cap allocation so that we won't exceed max_mem */ + if (alloc_size + (PAGE_SIZE << order) > max_mem) { + order = get_order(max_mem - alloc_size); + if (order) + order--; + } + size = PAGE_SIZE << order; + + folio = folio_alloc(GFP_KERNEL | __GFP_NORETRY, order); + if (!folio) + goto err_free_folios; + + state->folios[state->nr_folios++] = folio; + addr = folio_address(folio); + get_random_bytes(addr, size); + csum = csum_partial(addr, size, csum); + alloc_size += size; + } + + state->csum = csum; + return 0; + +err_free_folios: + for (int i = 0; i < state->nr_folios; i++) + folio_put(state->folios[i]); + return -ENOMEM; +} + +static int kho_test_save(void) +{ + struct kho_test_state *state = &kho_test_state; + struct folio **folios __free(kvfree) = NULL; + unsigned long max_nr; + int err; + + max_mem = PAGE_ALIGN(max_mem); + max_nr = max_mem >> PAGE_SHIFT; + + folios = kvmalloc_array(max_nr, sizeof(*state->folios), GFP_KERNEL); + if (!folios) + return -ENOMEM; + state->folios = folios; + + err = kho_test_generate_data(state); + if (err) + return err; + + err = kho_test_prepare_fdt(state); + if (err) + return err; + + return register_kho_notifier(&kho_test_nb); +} + +static int kho_test_restore_data(const void *fdt, int node) +{ + const unsigned int *nr_folios; + const phys_addr_t *folios_info; + const __wsum *old_csum; + __wsum csum = 0; + int len; + + node = fdt_path_offset(fdt, "/data"); + + nr_folios = fdt_getprop(fdt, node, "nr_folios", &len); + if (!nr_folios || len != sizeof(*nr_folios)) + return -EINVAL; + + old_csum = fdt_getprop(fdt, node, "csum", &len); + if (!old_csum || len != sizeof(*old_csum)) + return -EINVAL; + + folios_info = fdt_getprop(fdt, node, "folios_info", &len); + if (!folios_info || len != sizeof(*folios_info) * *nr_folios) + return -EINVAL; + + for (int i = 0; i < *nr_folios; i++) { + unsigned int order = folios_info[i] & ~PAGE_MASK; + phys_addr_t phys = folios_info[i] & PAGE_MASK; + unsigned int size = PAGE_SIZE << order; + struct folio *folio; + + folio = kho_restore_folio(phys); + if (!folio) + break; + + if (folio_order(folio) != order) + break; + + csum = csum_partial(folio_address(folio), size, csum); + folio_put(folio); + } + + if (csum != *old_csum) + return -EINVAL; + + return 0; +} + +static int kho_test_restore(phys_addr_t fdt_phys) +{ + void *fdt = phys_to_virt(fdt_phys); + const unsigned int *magic; + int node, len, err; + + node = fdt_path_offset(fdt, "/"); + if (node < 0) + return -EINVAL; + + if (fdt_node_check_compatible(fdt, node, KHO_TEST_COMPAT)) + return -EINVAL; + + magic = fdt_getprop(fdt, node, "magic", &len); + if (!magic || len != sizeof(*magic)) + return -EINVAL; + + if (*magic != KHO_TEST_MAGIC) + return -EINVAL; + + err = kho_test_restore_data(fdt, node); + if (err) + return err; + + pr_info("KHO restore succeeded\n"); + return 0; +} + +static int __init kho_test_init(void) +{ + phys_addr_t fdt_phys; + int err; + + err = kho_retrieve_subtree(KHO_TEST_FDT, &fdt_phys); + if (!err) + return kho_test_restore(fdt_phys); + + if (err != -ENOENT) { + pr_warn("failed to retrieve %s FDT: %d\n", KHO_TEST_FDT, err); + return err; + } + + return kho_test_save(); +} +module_init(kho_test_init); + +static void kho_test_cleanup(void) +{ + for (int i = 0; i < kho_test_state.nr_folios; i++) + folio_put(kho_test_state.folios[i]); + + kvfree(kho_test_state.folios); +} + +static void __exit kho_test_exit(void) +{ + unregister_kho_notifier(&kho_test_nb); + kho_test_cleanup(); +} +module_exit(kho_test_exit); + +MODULE_AUTHOR("Mike Rapoport <rppt@kernel.org>"); +MODULE_DESCRIPTION("KHO test module"); +MODULE_LICENSE("GPL"); diff --git a/tools/testing/selftests/kho/arm64.conf b/tools/testing/selftests/kho/arm64.conf new file mode 100644 index 000000000000..ee696807cd35 --- /dev/null +++ b/tools/testing/selftests/kho/arm64.conf @@ -0,0 +1,9 @@ +QEMU_CMD="qemu-system-aarch64 -M virt -cpu max" +QEMU_KCONFIG=" +CONFIG_SERIAL_AMBA_PL010=y +CONFIG_SERIAL_AMBA_PL010_CONSOLE=y +CONFIG_SERIAL_AMBA_PL011=y +CONFIG_SERIAL_AMBA_PL011_CONSOLE=y +" +KERNEL_IMAGE="Image" +KERNEL_CMDLINE="console=ttyAMA0" diff --git a/tools/testing/selftests/kho/init.c b/tools/testing/selftests/kho/init.c new file mode 100644 index 000000000000..8034e24c6bf6 --- /dev/null +++ b/tools/testing/selftests/kho/init.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0 + +#ifndef NOLIBC +#include <errno.h> +#include <stdio.h> +#include <unistd.h> +#include <fcntl.h> +#include <syscall.h> +#include <sys/mount.h> +#include <sys/reboot.h> +#endif + +/* from arch/x86/include/asm/setup.h */ +#define COMMAND_LINE_SIZE 2048 + +/* from include/linux/kexex.h */ +#define KEXEC_FILE_NO_INITRAMFS 0x00000004 + +#define KHO_FINILIZE "/debugfs/kho/out/finalize" +#define KERNEL_IMAGE "/kernel" + +static int mount_filesystems(void) +{ + if (mount("debugfs", "/debugfs", "debugfs", 0, NULL) < 0) + return -1; + + return mount("proc", "/proc", "proc", 0, NULL); +} + +static int kho_enable(void) +{ + const char enable[] = "1"; + int fd; + + fd = open(KHO_FINILIZE, O_RDWR); + if (fd < 0) + return -1; + + if (write(fd, enable, sizeof(enable)) != sizeof(enable)) + return 1; + + close(fd); + return 0; +} + +static long kexec_file_load(int kernel_fd, int initrd_fd, + unsigned long cmdline_len, const char *cmdline, + unsigned long flags) +{ + return syscall(__NR_kexec_file_load, kernel_fd, initrd_fd, cmdline_len, + cmdline, flags); +} + +static int kexec_load(void) +{ + char cmdline[COMMAND_LINE_SIZE]; + ssize_t len; + int fd, err; + + fd = open("/proc/cmdline", O_RDONLY); + if (fd < 0) + return -1; + + len = read(fd, cmdline, sizeof(cmdline)); + close(fd); + if (len < 0) + return -1; + + /* replace \n with \0 */ + cmdline[len - 1] = 0; + fd = open(KERNEL_IMAGE, O_RDONLY); + if (fd < 0) + return -1; + + err = kexec_file_load(fd, -1, len, cmdline, KEXEC_FILE_NO_INITRAMFS); + close(fd); + + return err ? : 0; +} + +int main(int argc, char *argv[]) +{ + if (mount_filesystems()) + goto err_reboot; + + if (kho_enable()) + goto err_reboot; + + if (kexec_load()) + goto err_reboot; + + if (reboot(RB_KEXEC)) + goto err_reboot; + + return 0; + +err_reboot: + reboot(RB_AUTOBOOT); + return -1; +} diff --git a/tools/testing/selftests/kho/vmtest.sh b/tools/testing/selftests/kho/vmtest.sh new file mode 100755 index 000000000000..ec70a17bd476 --- /dev/null +++ b/tools/testing/selftests/kho/vmtest.sh @@ -0,0 +1,183 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 + +set -ue + +CROSS_COMPILE="${CROSS_COMPILE:-""}" + +test_dir=$(realpath "$(dirname "$0")") +kernel_dir=$(realpath "$test_dir/../../../..") + +tmp_dir=$(mktemp -d /tmp/kho-test.XXXXXXXX) +headers_dir="$tmp_dir/usr" +initrd_dir="$tmp_dir/initrd" +initrd="$tmp_dir/initrd.cpio" + +source "$test_dir/../kselftest/ktap_helpers.sh" + +function usage() { + cat <<EOF +$0 [-d build_dir] [-j jobs] [-t target_arch] [-h] +Options: + -d) path to the kernel build directory + -j) number of jobs for compilation, similar to -j in make + -t) run test for target_arch, requires CROSS_COMPILE set + supported targets: aarch64, x86_64 + -h) display this help +EOF +} + +function cleanup() { + rm -fr "$tmp_dir" + ktap_finished +} +trap cleanup EXIT + +function skip() { + local msg=${1:-""} + + ktap_test_skip "$msg" + exit "$KSFT_SKIP" +} + +function fail() { + local msg=${1:-""} + + ktap_test_fail "$msg" + exit "$KSFT_FAIL" +} + +function build_kernel() { + local build_dir=$1 + local make_cmd=$2 + local arch_kconfig=$3 + local kimage=$4 + + local kho_config="$tmp_dir/kho.config" + local kconfig="$build_dir/.config" + + # enable initrd, KHO and KHO test in kernel configuration + tee "$kconfig" > "$kho_config" <<EOF +CONFIG_BLK_DEV_INITRD=y +CONFIG_KEXEC_HANDOVER=y +CONFIG_TEST_KEXEC_HANDOVER=y +CONFIG_DEBUG_KERNEL=y +CONFIG_DEBUG_VM=y +$arch_kconfig +EOF + + make_cmd="$make_cmd -C $kernel_dir O=$build_dir" + $make_cmd olddefconfig + + # verify that kernel confiration has all necessary options + while read -r opt ; do + grep "$opt" "$kconfig" &>/dev/null || skip "$opt is missing" + done < "$kho_config" + + $make_cmd "$kimage" + $make_cmd headers_install INSTALL_HDR_PATH="$headers_dir" +} + +function mkinitrd() { + local kernel=$1 + + mkdir -p "$initrd_dir"/{dev,debugfs,proc} + sudo mknod "$initrd_dir/dev/console" c 5 1 + + "$CROSS_COMPILE"gcc -s -static -Os -nostdinc -I"$headers_dir/include" \ + -fno-asynchronous-unwind-tables -fno-ident -nostdlib \ + -include "$test_dir/../../../include/nolibc/nolibc.h" \ + -o "$initrd_dir/init" "$test_dir/init.c" \ + + cp "$kernel" "$initrd_dir/kernel" + + pushd "$initrd_dir" &>/dev/null + find . | cpio -H newc --create > "$initrd" 2>/dev/null + popd &>/dev/null +} + +function run_qemu() { + local qemu_cmd=$1 + local cmdline=$2 + local kernel=$3 + local serial="$tmp_dir/qemu.serial" + + cmdline="$cmdline kho=on panic=-1" + + $qemu_cmd -m 1G -smp 2 -no-reboot -nographic -nodefaults \ + -accel kvm -accel hvf -accel tcg \ + -serial file:"$serial" \ + -append "$cmdline" \ + -kernel "$kernel" \ + -initrd "$initrd" + + grep "KHO restore succeeded" "$serial" &> /dev/null || fail "KHO failed" +} + +function target_to_arch() { + local target=$1 + + case $target in + aarch64) echo "arm64" ;; + x86_64) echo "x86" ;; + *) skip "architecture $target is not supported" + esac +} + +function main() { + local build_dir="$kernel_dir/.kho" + local jobs=$(($(nproc) * 2)) + local target="$(uname -m)" + + # skip the test if any of the preparation steps fails + set -o errtrace + trap skip ERR + + while getopts 'hd:j:t:' opt; do + case $opt in + d) + build_dir="$OPTARG" + ;; + j) + jobs="$OPTARG" + ;; + t) + target="$OPTARG" + ;; + h) + usage + exit 0 + ;; + *) + echo Unknown argument "$opt" + usage + exit 1 + ;; + esac + done + + ktap_print_header + ktap_set_plan 1 + + if [[ "$target" != "$(uname -m)" ]] && [[ -z "$CROSS_COMPILE" ]]; then + skip "Cross-platform testing needs to specify CROSS_COMPILE" + fi + + mkdir -p "$build_dir" + local arch=$(target_to_arch "$target") + source "$test_dir/$arch.conf" + + # build the kernel and create initrd + # initrd includes the kernel image that will be kexec'ed + local make_cmd="make ARCH=$arch CROSS_COMPILE=$CROSS_COMPILE -j$jobs" + build_kernel "$build_dir" "$make_cmd" "$QEMU_KCONFIG" "$KERNEL_IMAGE" + + local kernel="$build_dir/arch/$arch/boot/$KERNEL_IMAGE" + mkinitrd "$kernel" + + run_qemu "$QEMU_CMD" "$KERNEL_CMDLINE" "$kernel" + + ktap_test_pass "KHO succeeded" +} + +main "$@" diff --git a/tools/testing/selftests/kho/x86.conf b/tools/testing/selftests/kho/x86.conf new file mode 100644 index 000000000000..b419e610ca22 --- /dev/null +++ b/tools/testing/selftests/kho/x86.conf @@ -0,0 +1,7 @@ +QEMU_CMD=qemu-system-x86_64 +QEMU_KCONFIG=" +CONFIG_SERIAL_8250=y +CONFIG_SERIAL_8250_CONSOLE=y +" +KERNEL_IMAGE="bzImage" +KERNEL_CMDLINE="console=ttyS0" |