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[34.86.47.53]) by smtp.gmail.com with ESMTPSA id 00721157ae682-787d68754d3sm990817b3.26.2025.11.07.13.06.09 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 Nov 2025 13:06:10 -0800 (PST) From: Pasha Tatashin To: pratyush@kernel.org, jasonmiu@google.com, graf@amazon.com, pasha.tatashin@soleen.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, zhangguopeng@kylinos.cn, 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 Subject: [PATCH v5 20/22] selftests/liveupdate: Add kexec-based selftest for session lifecycle Date: Fri, 7 Nov 2025 16:03:18 -0500 Message-ID: <20251107210526.257742-21-pasha.tatashin@soleen.com> X-Mailer: git-send-email 2.51.2.1041.gc1ab5b90ca-goog In-Reply-To: <20251107210526.257742-1-pasha.tatashin@soleen.com> References: <20251107210526.257742-1-pasha.tatashin@soleen.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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=E2=80=94preserving state via Kexec Hand= over and restoring it in a new kernel=E2=80=94works 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 | 6 + .../selftests/liveupdate/luo_kexec_simple.c | 114 ++++++++++++ .../selftests/liveupdate/luo_test_utils.c | 168 ++++++++++++++++++ .../selftests/liveupdate/luo_test_utils.h | 39 ++++ 6 files changed, 360 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/se= lftests/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 ?=3D -I../../../../usr/include CFLAGS +=3D -Wall -O2 -Wno-unused-function CFLAGS +=3D $(KHDR_INCLUDES) +LDFLAGS +=3D -static +OUTPUT ?=3D . + +# --- Test Configuration (Edit this section when adding new tests) --- +LUO_SHARED_SRCS :=3D luo_test_utils.c +LUO_SHARED_HDRS +=3D luo_test_utils.h + +LUO_MANUAL_TESTS +=3D luo_kexec_simple + +TEST_FILES +=3D do_kexec.sh =20 TEST_GEN_PROGS +=3D liveupdate =20 +# --- Automatic Rule Generation (Do not edit below) --- + +TEST_GEN_PROGS_EXTENDED +=3D $(LUO_MANUAL_TESTS) + +# Define the full list of sources for each manual test. +$(foreach test,$(LUO_MANUAL_TESTS), \ + $(eval $(test)_SOURCES :=3D $(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 '$$' to escape automatic variables for the 'eval' comman= d. +$(foreach test,$(LUO_MANUAL_TESTS), \ + $(eval $(OUTPUT)/$(test): $($(test)_SOURCES) $(LUO_SHARED_HDRS) \ + $(call msg,LINK,,$$@) ; \ + $(Q)$(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..bb396a92c3b8 --- /dev/null +++ b/tools/testing/selftests/liveupdate/do_kexec.sh @@ -0,0 +1,6 @@ +#!/bin/sh +# SPDX-License-Identifier: GPL-2.0 +set -e + +kexec -l -s --reuse-cmdline /boot/bzImage +kexec -e 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 =3D 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) !=3D 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 !=3D 2) + fail_exit("Expected stage 2, but state file contains %d", stage); + + ksft_print_msg("[STAGE 2] Retrieving session '%s'...\n", TEST_SESSION_NAM= E); + session_fd =3D 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 =3D 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 =3D 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 =3D luo_retrieve_session(luo_fd, STATE_SESSION_NAME); + if (state_session_fd =3D=3D -ENOENT) { + run_stage_1(luo_fd); + } else if (state_session_fd >=3D 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/te= sting/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 =3D { .size =3D 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 =3D { .size =3D 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 =3D { .size =3D sizeof(arg) }; + long page_size =3D sysconf(_SC_PAGE_SIZE); + void *map =3D MAP_FAILED; + int mfd =3D -1, ret =3D -1; + + mfd =3D memfd_create("test_mfd", 0); + if (mfd < 0) + return -errno; + + if (ftruncate(mfd, page_size) !=3D 0) + goto out; + + map =3D mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, mfd, 0); + if (map =3D=3D MAP_FAILED) + goto out; + + snprintf(map, page_size, "%s", data); + munmap(map, page_size); + + arg.fd =3D mfd; + arg.token =3D token; + if (ioctl(session_fd, LIVEUPDATE_SESSION_PRESERVE_FD, &arg) < 0) + goto out; + + ret =3D 0; +out: + if (ret !=3D 0 && errno !=3D 0) + ret =3D -errno; + if (mfd >=3D 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 =3D { .size =3D sizeof(arg) }; + long page_size =3D sysconf(_SC_PAGE_SIZE); + void *map =3D MAP_FAILED; + int mfd =3D -1, ret =3D -1; + + arg.token =3D token; + if (ioctl(session_fd, LIVEUPDATE_SESSION_RETRIEVE_FD, &arg) < 0) + return -errno; + mfd =3D arg.fd; + + map =3D mmap(NULL, page_size, PROT_READ, MAP_SHARED, mfd, 0); + if (map =3D=3D MAP_FAILED) + goto out; + + if (expected_data && strcmp(expected_data, map) !=3D 0) { + ksft_print_msg("Data mismatch! Expected '%s', Got '%s'\n", + expected_data, (char *)map); + ret =3D -EINVAL; + goto out_munmap; + } + + ret =3D mfd; +out_munmap: + munmap(map, page_size); +out: + if (ret < 0 && errno !=3D 0) + ret =3D -errno; + if (ret < 0 && mfd >=3D 0) + close(mfd); + return ret; +} + +int luo_session_finish(int session_fd) +{ + struct liveupdate_session_finish arg =3D { .size =3D 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 =3D 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] =3D {0}; + int mfd; + + mfd =3D 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 =3D atoi(buf); + + close(mfd); +} diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.h b/tools/te= sting/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 *expect= ed_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 */ --=20 2.51.2.1041.gc1ab5b90ca-goog