From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-182.mta1.migadu.com (out-182.mta1.migadu.com [95.215.58.182]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 97D5C2F656A for ; Sun, 16 Nov 2025 18:54:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=95.215.58.182 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763319247; cv=none; b=dcYZbGsFVxYVonc0MFxtCcxtwxdHKtUcRPTvXNaw93X+eRrreS1fW3q1v/r0w3zuBP1HxMMpXnVf2godTt/aOgD1tUHfdaQGEogGjPOqcBgw4KZVVOaI+Xdm4YOAFQ4ar+Pjcq7ZmFHBxNO+wRAdv1dCVkgG2OzBwc83IWfy9WY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763319247; c=relaxed/simple; bh=1TioA97m703e5AJb04vx9Ka+wmw+uBLInwRZoOGwq9U=; h=Message-ID:Date:MIME-Version:Subject:To:References:From: In-Reply-To:Content-Type; b=W5vRhTPd/keFXwo7XRrpEqfTSJu9CsxFluYrd0cfkxNcQzh2svx8FtWMbD8qtXFI9WwG2yTDcbMWScaUIQyW0mocjeUIxybTzG4eOJWzSkFALiimBSQF6ZyZBfnfIAo9ftG2lAWA0Ml0JpWXQ72CHqXC+QiCb2aksDtVIzuka2g= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=dMFr36Cd; arc=none smtp.client-ip=95.215.58.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="dMFr36Cd" Message-ID: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1763319241; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/fxW02oqxRR0shu5+kTOAPvOk1qA6Rm/ysLiY5ikXEY=; b=dMFr36Cdydmmjf0hR6IX+hik30+iJEqG5/cXs2Hv3ThbWtirOSnwxbrOh53Dur6FUtNfY5 GS5zCWKsWu4cGyC4Qgbdsx9EdRPfF+Mvp7g/52mgOnpRXRcCWgV4zrftWac18hvHXth8HE ls+xJvtbrLaubtvPbYoPhY6/b5iyTUc= Date: Sun, 16 Nov 2025 10:53:34 -0800 Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v6 18/20] selftests/liveupdate: Add kexec-based selftest for session lifecycle To: Pasha Tatashin , pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, rppt@kernel.org, dmatlack@google.com, rientjes@google.com, corbet@lwn.net, rdunlap@infradead.org, ilpo.jarvinen@linux.intel.com, kanie@linux.alibaba.com, ojeda@kernel.org, aliceryhl@google.com, masahiroy@kernel.org, akpm@linux-foundation.org, tj@kernel.org, yoann.congal@smile.fr, mmaurer@google.com, roman.gushchin@linux.dev, chenridong@huawei.com, axboe@kernel.dk, mark.rutland@arm.com, jannh@google.com, vincent.guittot@linaro.org, hannes@cmpxchg.org, dan.j.williams@intel.com, david@redhat.com, joel.granados@kernel.org, rostedt@goodmis.org, anna.schumaker@oracle.com, song@kernel.org, linux@weissschuh.net, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-mm@kvack.org, gregkh@linuxfoundation.org, tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rafael@kernel.org, dakr@kernel.org, bartosz.golaszewski@linaro.org, cw00.choi@samsung.com, myungjoo.ham@samsung.com, yesanishhere@gmail.com, Jonathan.Cameron@huawei.com, quic_zijuhu@quicinc.com, aleksander.lobakin@intel.com, ira.weiny@intel.com, andriy.shevchenko@linux.intel.com, leon@kernel.org, lukas@wunner.de, bhelgaas@google.com, wagi@kernel.org, djeffery@redhat.com, stuart.w.hayes@gmail.com, ptyadav@amazon.de, lennart@poettering.net, brauner@kernel.org, linux-api@vger.kernel.org, linux-fsdevel@vger.kernel.org, saeedm@nvidia.com, ajayachandra@nvidia.com, jgg@nvidia.com, parav@nvidia.com, leonro@nvidia.com, witu@nvidia.com, hughd@google.com, skhawaja@google.com, chrisl@kernel.org References: <20251115233409.768044-1-pasha.tatashin@soleen.com> <20251115233409.768044-19-pasha.tatashin@soleen.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: <20251115233409.768044-19-pasha.tatashin@soleen.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2025/11/15 15:34, Pasha Tatashin 写道: > Introduce a kexec-based selftest, luo_kexec_simple, to validate the > end-to-end lifecycle of a Live Update Orchestrator (LUO) session across > a reboot. > > While existing tests verify the uAPI in a pre-reboot context, this test > ensures that the core functionality—preserving state via Kexec Handover > and restoring it in a new kernel—works as expected. > > The test operates in two stages, managing its state across the reboot by > preserving a dedicated "state session" containing a memfd. This > mechanism dogfoods the LUO feature itself for state tracking, making the > test self-contained. > > The test validates the following sequence: > > Stage 1 (Pre-kexec): > - Creates a test session (test-session). > - Creates and preserves a memfd with a known data pattern into the test > session. > - Creates the state-tracking session to signal progression to Stage 2. > - Executes a kexec reboot via a helper script. > > Stage 2 (Post-kexec): > - Retrieves the state-tracking session to confirm it is in the > post-reboot stage. > - Retrieves the preserved test session. > - Restores the memfd from the test session and verifies its contents > match the original data pattern written in Stage 1. > - Finalizes both the test and state sessions to ensure a clean > teardown. > > The test relies on a helper script (do_kexec.sh) to perform the reboot > and a shared utility library (luo_test_utils.c) for common LUO > operations, keeping the main test logic clean and focused. > > Signed-off-by: Pasha Tatashin > --- > tools/testing/selftests/liveupdate/.gitignore | 1 + > tools/testing/selftests/liveupdate/Makefile | 32 ++++ > .../testing/selftests/liveupdate/do_kexec.sh | 16 ++ > .../selftests/liveupdate/luo_kexec_simple.c | 114 ++++++++++++ > .../selftests/liveupdate/luo_test_utils.c | 168 ++++++++++++++++++ > .../selftests/liveupdate/luo_test_utils.h | 39 ++++ > 6 files changed, 370 insertions(+) > create mode 100755 tools/testing/selftests/liveupdate/do_kexec.sh > create mode 100644 tools/testing/selftests/liveupdate/luo_kexec_simple.c > create mode 100644 tools/testing/selftests/liveupdate/luo_test_utils.c > create mode 100644 tools/testing/selftests/liveupdate/luo_test_utils.h > > diff --git a/tools/testing/selftests/liveupdate/.gitignore b/tools/testing/selftests/liveupdate/.gitignore > index af6e773cf98f..daeef116174d 100644 > --- a/tools/testing/selftests/liveupdate/.gitignore > +++ b/tools/testing/selftests/liveupdate/.gitignore > @@ -1 +1,2 @@ > /liveupdate > +/luo_kexec_simple > diff --git a/tools/testing/selftests/liveupdate/Makefile b/tools/testing/selftests/liveupdate/Makefile > index 2a573c36016e..1563ac84006a 100644 > --- a/tools/testing/selftests/liveupdate/Makefile > +++ b/tools/testing/selftests/liveupdate/Makefile > @@ -1,7 +1,39 @@ > # SPDX-License-Identifier: GPL-2.0-only > + > +KHDR_INCLUDES ?= -I../../../../usr/include > CFLAGS += -Wall -O2 -Wno-unused-function > CFLAGS += $(KHDR_INCLUDES) > +LDFLAGS += -static > +OUTPUT ?= . > + > +# --- Test Configuration (Edit this section when adding new tests) --- > +LUO_SHARED_SRCS := luo_test_utils.c > +LUO_SHARED_HDRS += luo_test_utils.h > + > +LUO_MANUAL_TESTS += luo_kexec_simple > + > +TEST_FILES += do_kexec.sh > > TEST_GEN_PROGS += liveupdate > > +# --- Automatic Rule Generation (Do not edit below) --- > + > +TEST_GEN_PROGS_EXTENDED += $(LUO_MANUAL_TESTS) > + > +# Define the full list of sources for each manual test. > +$(foreach test,$(LUO_MANUAL_TESTS), \ > + $(eval $(test)_SOURCES := $(test).c $(LUO_SHARED_SRCS))) > + > +# This loop automatically generates an explicit build rule for each manual test. > +# It includes dependencies on the shared headers and makes the output > +# executable. > +# Note the use of '$$' to escape automatic variables for the 'eval' command. > +$(foreach test,$(LUO_MANUAL_TESTS), \ > + $(eval $(OUTPUT)/$(test): $($(test)_SOURCES) $(LUO_SHARED_HDRS) \ > + $(call msg,LINK,,$$@) ; \ > + $(Q)$(LINK.c) $$^ $(LDLIBS) -o $$@ ; \ > + $(Q)chmod +x $$@ \ > + ) \ > +) > + > include ../lib.mk > diff --git a/tools/testing/selftests/liveupdate/do_kexec.sh b/tools/testing/selftests/liveupdate/do_kexec.sh > new file mode 100755 > index 000000000000..3c7c6cafbef8 > --- /dev/null > +++ b/tools/testing/selftests/liveupdate/do_kexec.sh > @@ -0,0 +1,16 @@ > +#!/bin/sh > +# SPDX-License-Identifier: GPL-2.0 > +set -e > + > +# Use $KERNEL and $INITRAMFS to pass custom Kernel and optional initramfs > + > +KERNEL="${KERNEL:-/boot/bzImage}" > +set -- -l -s --reuse-cmdline "$KERNEL" > + > +INITRAMFS="${INITRAMFS:-/boot/initramfs}" > +if [ -f "$INITRAMFS" ]; then > + set -- "$@" --initrd="$INITRAMFS" > +fi > + > +kexec "$@" > +kexec -e Thanks a lot. Just with kernel image, it is not enough to boot the host. Adding initramfs will avoid the crash when the host boots. I have made tests to verify this. Reviewed-by: Zhu Yanjun Zhu Yanjun > diff --git a/tools/testing/selftests/liveupdate/luo_kexec_simple.c b/tools/testing/selftests/liveupdate/luo_kexec_simple.c > new file mode 100644 > index 000000000000..67ab6ebf9eec > --- /dev/null > +++ b/tools/testing/selftests/liveupdate/luo_kexec_simple.c > @@ -0,0 +1,114 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +/* > + * Copyright (c) 2025, Google LLC. > + * Pasha Tatashin > + * > + * A simple selftest to validate the end-to-end lifecycle of a LUO session > + * across a single kexec reboot. > + */ > + > +#include "luo_test_utils.h" > + > +/* Test-specific constants are now defined locally */ > +#define KEXEC_SCRIPT "./do_kexec.sh" > +#define TEST_SESSION_NAME "test-session" > +#define TEST_MEMFD_TOKEN 0x1A > +#define TEST_MEMFD_DATA "hello kexec world" > + > +/* Constants for the state-tracking mechanism, specific to this test file. */ > +#define STATE_SESSION_NAME "kexec_simple_state" > +#define STATE_MEMFD_TOKEN 999 > + > +/* Stage 1: Executed before the kexec reboot. */ > +static void run_stage_1(int luo_fd) > +{ > + int session_fd; > + > + ksft_print_msg("[STAGE 1] Starting pre-kexec setup...\n"); > + > + ksft_print_msg("[STAGE 1] Creating state file for next stage (2)...\n"); > + create_state_file(luo_fd, STATE_SESSION_NAME, STATE_MEMFD_TOKEN, 2); > + > + ksft_print_msg("[STAGE 1] Creating session '%s' and preserving memfd...\n", > + TEST_SESSION_NAME); > + session_fd = luo_create_session(luo_fd, TEST_SESSION_NAME); > + if (session_fd < 0) > + fail_exit("luo_create_session for '%s'", TEST_SESSION_NAME); > + > + if (create_and_preserve_memfd(session_fd, TEST_MEMFD_TOKEN, > + TEST_MEMFD_DATA) < 0) { > + fail_exit("create_and_preserve_memfd for token %#x", > + TEST_MEMFD_TOKEN); > + } > + > + ksft_print_msg("[STAGE 1] Executing kexec...\n"); > + if (system(KEXEC_SCRIPT) != 0) > + fail_exit("kexec script failed"); > + exit(EXIT_FAILURE); > +} > + > +/* Stage 2: Executed after the kexec reboot. */ > +static void run_stage_2(int luo_fd, int state_session_fd) > +{ > + int session_fd, mfd, stage; > + > + ksft_print_msg("[STAGE 2] Starting post-kexec verification...\n"); > + > + restore_and_read_stage(state_session_fd, STATE_MEMFD_TOKEN, &stage); > + if (stage != 2) > + fail_exit("Expected stage 2, but state file contains %d", stage); > + > + ksft_print_msg("[STAGE 2] Retrieving session '%s'...\n", TEST_SESSION_NAME); > + session_fd = luo_retrieve_session(luo_fd, TEST_SESSION_NAME); > + if (session_fd < 0) > + fail_exit("luo_retrieve_session for '%s'", TEST_SESSION_NAME); > + > + ksft_print_msg("[STAGE 2] Restoring and verifying memfd (token %#x)...\n", > + TEST_MEMFD_TOKEN); > + mfd = restore_and_verify_memfd(session_fd, TEST_MEMFD_TOKEN, > + TEST_MEMFD_DATA); > + if (mfd < 0) > + fail_exit("restore_and_verify_memfd for token %#x", TEST_MEMFD_TOKEN); > + close(mfd); > + > + ksft_print_msg("[STAGE 2] Test data verified successfully.\n"); > + ksft_print_msg("[STAGE 2] Finalizing test session...\n"); > + if (luo_session_finish(session_fd) < 0) > + fail_exit("luo_session_finish for test session"); > + close(session_fd); > + > + ksft_print_msg("[STAGE 2] Finalizing state session...\n"); > + if (luo_session_finish(state_session_fd) < 0) > + fail_exit("luo_session_finish for state session"); > + close(state_session_fd); > + > + ksft_print_msg("\n--- SIMPLE KEXEC TEST PASSED ---\n"); > +} > + > +int main(int argc, char *argv[]) > +{ > + int luo_fd; > + int state_session_fd; > + > + luo_fd = luo_open_device(); > + if (luo_fd < 0) > + ksft_exit_skip("Failed to open %s. Is the luo module loaded?\n", > + LUO_DEVICE); > + > + /* > + * Determine the stage by attempting to retrieve the state session. > + * If it doesn't exist (ENOENT), we are in Stage 1 (pre-kexec). > + */ > + state_session_fd = luo_retrieve_session(luo_fd, STATE_SESSION_NAME); > + if (state_session_fd == -ENOENT) { > + run_stage_1(luo_fd); > + } else if (state_session_fd >= 0) { > + /* We got a valid handle, pass it directly to stage 2 */ > + run_stage_2(luo_fd, state_session_fd); > + } else { > + fail_exit("Failed to check for state session"); > + } > + > + close(luo_fd); > +} > diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.c b/tools/testing/selftests/liveupdate/luo_test_utils.c > new file mode 100644 > index 000000000000..0a24105cbc54 > --- /dev/null > +++ b/tools/testing/selftests/liveupdate/luo_test_utils.c > @@ -0,0 +1,168 @@ > +// SPDX-License-Identifier: GPL-2.0-only > + > +/* > + * Copyright (c) 2025, Google LLC. > + * Pasha Tatashin > + */ > + > +#define _GNU_SOURCE > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "luo_test_utils.h" > + > +int luo_open_device(void) > +{ > + return open(LUO_DEVICE, O_RDWR); > +} > + > +int luo_create_session(int luo_fd, const char *name) > +{ > + struct liveupdate_ioctl_create_session arg = { .size = sizeof(arg) }; > + > + snprintf((char *)arg.name, LIVEUPDATE_SESSION_NAME_LENGTH, "%.*s", > + LIVEUPDATE_SESSION_NAME_LENGTH - 1, name); > + > + if (ioctl(luo_fd, LIVEUPDATE_IOCTL_CREATE_SESSION, &arg) < 0) > + return -errno; > + > + return arg.fd; > +} > + > +int luo_retrieve_session(int luo_fd, const char *name) > +{ > + struct liveupdate_ioctl_retrieve_session arg = { .size = sizeof(arg) }; > + > + snprintf((char *)arg.name, LIVEUPDATE_SESSION_NAME_LENGTH, "%.*s", > + LIVEUPDATE_SESSION_NAME_LENGTH - 1, name); > + > + if (ioctl(luo_fd, LIVEUPDATE_IOCTL_RETRIEVE_SESSION, &arg) < 0) > + return -errno; > + > + return arg.fd; > +} > + > +int create_and_preserve_memfd(int session_fd, int token, const char *data) > +{ > + struct liveupdate_session_preserve_fd arg = { .size = sizeof(arg) }; > + long page_size = sysconf(_SC_PAGE_SIZE); > + void *map = MAP_FAILED; > + int mfd = -1, ret = -1; > + > + mfd = memfd_create("test_mfd", 0); > + if (mfd < 0) > + return -errno; > + > + if (ftruncate(mfd, page_size) != 0) > + goto out; > + > + map = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, mfd, 0); > + if (map == MAP_FAILED) > + goto out; > + > + snprintf(map, page_size, "%s", data); > + munmap(map, page_size); > + > + arg.fd = mfd; > + arg.token = token; > + if (ioctl(session_fd, LIVEUPDATE_SESSION_PRESERVE_FD, &arg) < 0) > + goto out; > + > + ret = 0; > +out: > + if (ret != 0 && errno != 0) > + ret = -errno; > + if (mfd >= 0) > + close(mfd); > + return ret; > +} > + > +int restore_and_verify_memfd(int session_fd, int token, > + const char *expected_data) > +{ > + struct liveupdate_session_retrieve_fd arg = { .size = sizeof(arg) }; > + long page_size = sysconf(_SC_PAGE_SIZE); > + void *map = MAP_FAILED; > + int mfd = -1, ret = -1; > + > + arg.token = token; > + if (ioctl(session_fd, LIVEUPDATE_SESSION_RETRIEVE_FD, &arg) < 0) > + return -errno; > + mfd = arg.fd; > + > + map = mmap(NULL, page_size, PROT_READ, MAP_SHARED, mfd, 0); > + if (map == MAP_FAILED) > + goto out; > + > + if (expected_data && strcmp(expected_data, map) != 0) { > + ksft_print_msg("Data mismatch! Expected '%s', Got '%s'\n", > + expected_data, (char *)map); > + ret = -EINVAL; > + goto out_munmap; > + } > + > + ret = mfd; > +out_munmap: > + munmap(map, page_size); > +out: > + if (ret < 0 && errno != 0) > + ret = -errno; > + if (ret < 0 && mfd >= 0) > + close(mfd); > + return ret; > +} > + > +int luo_session_finish(int session_fd) > +{ > + struct liveupdate_session_finish arg = { .size = sizeof(arg) }; > + > + if (ioctl(session_fd, LIVEUPDATE_SESSION_FINISH, &arg) < 0) > + return -errno; > + > + return 0; > +} > + > +void create_state_file(int luo_fd, const char *session_name, int token, > + int next_stage) > +{ > + char buf[32]; > + int state_session_fd; > + > + state_session_fd = luo_create_session(luo_fd, session_name); > + if (state_session_fd < 0) > + fail_exit("luo_create_session for state tracking"); > + > + snprintf(buf, sizeof(buf), "%d", next_stage); > + if (create_and_preserve_memfd(state_session_fd, token, buf) < 0) > + fail_exit("create_and_preserve_memfd for state tracking"); > + > + /* > + * DO NOT close session FD, otherwise it is going to be unpreserved > + */ > +} > + > +void restore_and_read_stage(int state_session_fd, int token, int *stage) > +{ > + char buf[32] = {0}; > + int mfd; > + > + mfd = restore_and_verify_memfd(state_session_fd, token, NULL); > + if (mfd < 0) > + fail_exit("failed to restore state memfd"); > + > + if (read(mfd, buf, sizeof(buf) - 1) < 0) > + fail_exit("failed to read state mfd"); > + > + *stage = atoi(buf); > + > + close(mfd); > +} > diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.h b/tools/testing/selftests/liveupdate/luo_test_utils.h > new file mode 100644 > index 000000000000..093e787b9f4b > --- /dev/null > +++ b/tools/testing/selftests/liveupdate/luo_test_utils.h > @@ -0,0 +1,39 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +/* > + * Copyright (c) 2025, Google LLC. > + * Pasha Tatashin > + * > + * Utility functions for LUO kselftests. > + */ > + > +#ifndef LUO_TEST_UTILS_H > +#define LUO_TEST_UTILS_H > + > +#include > +#include > +#include > +#include "../kselftest.h" > + > +#define LUO_DEVICE "/dev/liveupdate" > + > +#define fail_exit(fmt, ...) \ > + ksft_exit_fail_msg("[%s:%d] " fmt " (errno: %s)\n", \ > + __func__, __LINE__, ##__VA_ARGS__, strerror(errno)) > + > +/* Generic LUO and session management helpers */ > +int luo_open_device(void); > +int luo_create_session(int luo_fd, const char *name); > +int luo_retrieve_session(int luo_fd, const char *name); > +int luo_session_finish(int session_fd); > + > +/* Generic file preservation and restoration helpers */ > +int create_and_preserve_memfd(int session_fd, int token, const char *data); > +int restore_and_verify_memfd(int session_fd, int token, const char *expected_data); > + > +/* Kexec state-tracking helpers */ > +void create_state_file(int luo_fd, const char *session_name, int token, > + int next_stage); > +void restore_and_read_stage(int state_session_fd, int token, int *stage); > + > +#endif /* LUO_TEST_UTILS_H */