From nobody Thu Apr 9 11:15:04 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 8B16F39A056; Sat, 4 Apr 2026 10:25:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298305; cv=none; b=l78oQdiziOBWZb2J1TkDR0PDvIeT4DRA/pejMKceBjvR/7GA5hCPvWGcW/iEsmep1skOQ2haSPPo+PtMhUXYo1qeWoyslVIbZovvPVR/f4OpqgYNWY5MSGgObTt7pZ/KOqp7aI7GAV04/UgaQ/aHUEeYvVQlalzpzCVmrUQvO04= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298305; c=relaxed/simple; bh=/EUjIrH0nCwQKenCVjkx2cRPuoQiXcxmaLv25odT908=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=AyOGAoOge7Z63LhBrNCTX4wyIOd2fAA1aaLaVBtYsgSTnXmP2rPZZfbBwM9RCvnuoEhpPXjWIsjLhyYRyMSb5NLLvlLA5WrKmM9GNdmoMvczZNgc9QNNo8lsNsO2SmuWowKYykDJfD7W4MTGStGoEkNmRKRieRvKDHose7yupXU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=j1xr4ow1; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="j1xr4ow1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 45B93C19425; Sat, 4 Apr 2026 10:25:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775298305; bh=/EUjIrH0nCwQKenCVjkx2cRPuoQiXcxmaLv25odT908=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=j1xr4ow13eYqPzo66Vy7ar9HIiMtgRGMDsnKwNvIASkjsql8yqCEakVNO1Pv2rBhe aL183bC/PXsEwZZFmWvwz/XivGToT7uyDgmXzJPsrn3sqaxTrpEBqQSHT/zLZdDMoo AuKQwlKDV1wQBYhYDT/hDJPFjV+2Z5C2JqO7P1RF2gywkf+6Zu66QgSrha64T5/3u4 vq1zFsskLW5KQtI5VIgRfidZRWs5DENxK5TsIvH+zwuI9MBksbIT18PQbSygstt5aT 2xPO0Lr1s/uOqZ/9UEPJuS9mJotn9KpZ4l8KFjJYKmJRSOqjBGqaJSr3lXDYDOrn+3 RkgyjKWYlkchw== From: Pratyush Yadav To: Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Shuah Khan , Andrew Morton , Usama Arif Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 1/6] selftests/liveupdate: add framework for memfd tests Date: Sat, 4 Apr 2026 10:24:44 +0000 Message-ID: <20260404102452.4091740-2-pratyush@kernel.org> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog In-Reply-To: <20260404102452.4091740-1-pratyush@kernel.org> References: <20260404102452.4091740-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Pratyush Yadav (Google)" Currently memfd preservation using LUO is only tested indirectly via the luo_multi_session or luo_kexec_simple tests. Their main purpose is to test other live update functionality. Add a framework for writing memfd tests. The framework hooks into the kselftest harness, but adds some things on top to make it suitable for live update. The LUO FD (/dev/liveupdate) can only be opened by one process at a time. Each test runs in its own process. This means the LUO FD must be owned by the main process and shared to children. main() opens the LUO FD and shares it to child runners using a global variable. Live update tests run in two stages. One before kexec and one after. Detect the stage using a special state session. If the session is present, it means the test is in post-kexec state. Additionally, take in an optional --stage argument that lets callers specify expected stage. This is useful as a safety net to catch LUO core failures. If LUO core fails to preserve the state session properly, this option can help detect this and fail early. Since the option is not recognized by the kselftest harness, remove it from argv before calling test_harness_run(). Reviewed-by: Mike Rapoport (Microsoft) Signed-off-by: Pratyush Yadav (Google) --- tools/testing/selftests/liveupdate/Makefile | 1 + .../testing/selftests/liveupdate/luo_memfd.c | 78 +++++++++++++++++++ 2 files changed, 79 insertions(+) create mode 100644 tools/testing/selftests/liveupdate/luo_memfd.c diff --git a/tools/testing/selftests/liveupdate/Makefile b/tools/testing/se= lftests/liveupdate/Makefile index 080754787ede..051daae55eec 100644 --- a/tools/testing/selftests/liveupdate/Makefile +++ b/tools/testing/selftests/liveupdate/Makefile @@ -6,6 +6,7 @@ TEST_GEN_PROGS +=3D liveupdate =20 TEST_GEN_PROGS_EXTENDED +=3D luo_kexec_simple TEST_GEN_PROGS_EXTENDED +=3D luo_multi_session +TEST_GEN_PROGS_EXTENDED +=3D luo_memfd =20 TEST_FILES +=3D do_kexec.sh =20 diff --git a/tools/testing/selftests/liveupdate/luo_memfd.c b/tools/testing= /selftests/liveupdate/luo_memfd.c new file mode 100644 index 000000000000..c1f3275963dc --- /dev/null +++ b/tools/testing/selftests/liveupdate/luo_memfd.c @@ -0,0 +1,78 @@ +// SPDX-License-Identifier: GPL-2.0 + +/* + * Copyright (c) 2026, Google LLC. + * Pratyush Yadav (Google) + */ + +/* + * Selftests for memfd preservation via LUO. + */ + +#include +#include +#include +#include +#include + +#include + +#include "../kselftest.h" +#include "../kselftest_harness.h" + +#include "luo_test_utils.h" + +#define STATE_SESSION_NAME "luo-state" +#define STATE_MEMFD_TOKEN 1 + +static int luo_fd =3D -1; +static int stage; + +int main(int argc, char *argv[]) +{ + int expected_stage =3D 0; + int session; + + /* + * The test takes an optional --stage argument. This lets callers + * provide the expected stage, and if that doesn't match the test errors + * out. + * + * Look for the stage. Since test_harness_run() doesn't recognize it, + * once found, remove it from argv. + */ + for (int i =3D 1; i < argc; i++) { + if (strcmp(argv[i], "--stage") =3D=3D 0) { + if (i + 1 < argc) { + expected_stage =3D atoi(argv[i + 1]); + memmove(&argv[i], &argv[i + 2], (argc - i - 1) * sizeof(char *)); + argc -=3D 2; + i--; + } else { + ksft_exit_fail_msg("Option --stage requires an argument\n"); + } + } + } + + luo_fd =3D luo_open_device(); + if (luo_fd < 0) + ksft_exit_skip("Failed to open %s (%s) device. Is LUO enabled?\n", + LUO_DEVICE, strerror(errno)); + + session =3D luo_retrieve_session(luo_fd, STATE_SESSION_NAME); + if (session =3D=3D -ENOENT) + stage =3D 1; + else if (session >=3D 0) + stage =3D 2; + else + ksft_exit_fail_perror("Failed to check for state session"); + + if (expected_stage && expected_stage !=3D stage) + ksft_exit_fail_msg("Stage mismatch: expected %d, got %d\n", + expected_stage, stage); + + if (stage =3D=3D 1) + create_state_file(luo_fd, STATE_SESSION_NAME, STATE_MEMFD_TOKEN, 2); + + return test_harness_run(argc, argv); +} --=20 2.53.0.1213.gd9a14994de-goog From nobody Thu Apr 9 11:15:04 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 BCE463A9DAD; Sat, 4 Apr 2026 10:25:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298307; cv=none; b=X6jvoJy7G4cC5n4L1MBtWaBkkB9czOKcrA3WqdodHJVRZh9eyn2pl6zkdq3dMRG7fJwZ+DzE6rHpcY/+yfShP7ZRdPeG5dM+fFvxqrq0wrnF9oilTVMbOxuc7T5oSUfu9ZylBwGb3djIRv+fgau06xKqJHn+HaQGMDxiys1HtKc= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298307; c=relaxed/simple; bh=4wUqlSk5F6JPXlOV4nO49t1axV7aX2mPAkRXPiBcSU8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=uKvv8QV+NokFVu8xC9KZA0L/RVer7L+L4pbkY+At85YDEtDZBWZuWH+6UssBZiLhdvS5kcpK3AJaCBYH9UDb0mNG7s9GVzjlCfEVeBuKPje9CSvTrUZQioDXlOUWdfmuvpphNsMglt5/Owwseu8D1ktG46xfVkUDZZ8QsRX98xc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=iRW6hSC5; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="iRW6hSC5" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 821CEC2BCB3; Sat, 4 Apr 2026 10:25:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775298307; bh=4wUqlSk5F6JPXlOV4nO49t1axV7aX2mPAkRXPiBcSU8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iRW6hSC5CY+es5Pz7Wk3TJeZUOI0x46U73T6qNo+XSobA8Up1tzhuDhurEq37oMlG EkCTyNJhMK0O1w20IYtoyDl/Bttv6DqIP5knyo9gGXFNF6azYe9rB1kBo2zv0/Hst8 8fBgtGHqGFU88oiH70jUrekPj+Sr013diNBm5OqqLx31daCba1UHcp4pqgaRRPGnwZ TNlkE7vPNeVd2cw2LiRzbwYZ7x6Y1nAocXNPV+UgMO7SVCa6fbBjCtV5r2L11ifPX4 geSMcZAifHECsMVI04oUcbgwuQueTMFDBpIaPE4IVf3Tfvvg3SlomEQwLBCaN2e1ko pz4tEX2p2pbag== From: Pratyush Yadav To: Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Shuah Khan , Andrew Morton , Usama Arif Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 2/6] selftests/liveupdate: add helper functions for memfd tests Date: Sat, 4 Apr 2026 10:24:45 +0000 Message-ID: <20260404102452.4091740-3-pratyush@kernel.org> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog In-Reply-To: <20260404102452.4091740-1-pratyush@kernel.org> References: <20260404102452.4091740-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Pratyush Yadav (Google)" Add some helper functions that will be used by memfd tests. This moves some of the complexity out of the test itself, which results in better test readability and less code duplication. Reviewed-by: Mike Rapoport (Microsoft) Signed-off-by: Pratyush Yadav Signed-off-by: Pratyush Yadav (Google) --- .../selftests/liveupdate/luo_test_utils.c | 191 +++++++++++++++++- .../selftests/liveupdate/luo_test_utils.h | 10 + 2 files changed, 200 insertions(+), 1 deletion(-) diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.c b/tools/te= sting/selftests/liveupdate/luo_test_utils.c index 3c8721c505df..ceb918ef9813 100644 --- a/tools/testing/selftests/liveupdate/luo_test_utils.c +++ b/tools/testing/selftests/liveupdate/luo_test_utils.c @@ -1,8 +1,12 @@ // SPDX-License-Identifier: GPL-2.0-only =20 /* - * Copyright (c) 2025, Google LLC. + * Copyright (c) 2025-2026, Google LLC. * Pasha Tatashin + * Pratyush Yadav (Google) + * + * Copyright (C) 2025 Amazon.com Inc. or its affiliates. + * Pratyush Yadav */ =20 #define _GNU_SOURCE @@ -20,9 +24,194 @@ #include #include #include +#include +#include =20 #include "luo_test_utils.h" =20 +int cwd_is_tmpfs(void) +{ + struct statfs buf; + + if (statfs(".", &buf) < 0) + return -errno; + + return buf.f_type =3D=3D TMPFS_MAGIC; +} + +/* Read exactly specified size from fd. Any less results in error. */ +int read_size(int fd, char *buffer, size_t size) +{ + size_t remain =3D size; + ssize_t bytes_read; + + while (remain) { + bytes_read =3D read(fd, buffer, remain); + if (bytes_read =3D=3D 0) + return -ENODATA; + if (bytes_read < 0) { + if (errno =3D=3D EINTR) + continue; + else + return -errno; + } + + remain -=3D bytes_read; + buffer +=3D bytes_read; + } + + return 0; +} + +/* Write exactly specified size from fd. Any less results in error. */ +int write_size(int fd, const char *buffer, size_t size) +{ + size_t remain =3D size; + ssize_t written; + + while (remain) { + written =3D write(fd, buffer, remain); + if (written =3D=3D 0) + return -EIO; + if (written < 0) { + if (errno =3D=3D EINTR) + continue; + else + return -errno; + } + + remain -=3D written; + buffer +=3D written; + } + + return 0; +} + +int generate_random_data(char *buffer, size_t size) +{ + int fd, ret; + + fd =3D open("/dev/urandom", O_RDONLY); + if (fd < 0) + return -errno; + + ret =3D read_size(fd, buffer, size); + close(fd); + return ret; +} + +int save_test_data(const char *filename, const char *buffer, size_t size) +{ + int fd, ret; + + fd =3D open(filename, O_RDWR | O_CREAT | O_TRUNC, 0666); + if (fd < 0) + return -errno; + + ret =3D write_size(fd, buffer, size); + fsync(fd); + close(fd); + return ret; +} + +int load_test_data(const char *filename, char *buffer, size_t size) +{ + int fd, ret; + + fd =3D open(filename, O_RDONLY); + if (fd < 0) + return -errno; + + ret =3D read_size(fd, buffer, size); + close(fd); + return ret; +} + +/* Create and initialize a memfd with random data. */ +int create_random_memfd(const char *memfd_name, char *buffer, size_t size) +{ + int fd; + int ret; + + fd =3D memfd_create(memfd_name, 0); + if (fd < 0) + return -errno; + + ret =3D generate_random_data(buffer, size); + if (ret < 0) { + close(fd); + return ret; + } + + ret =3D write_size(fd, buffer, size); + if (ret < 0) { + close(fd); + return ret; + } + + /* Reset file position to beginning */ + if (lseek(fd, 0, SEEK_SET) < 0) { + ret =3D -errno; + close(fd); + return ret; + } + + return fd; +} + +/* + * Make sure fd contains expected data up to size. Returns 0 on success, 1= on + * data mismatch, -errno on error. + */ +int verify_fd_content_read(int fd, const char *expected_data, size_t size) +{ + char *buffer; + int ret; + + buffer =3D malloc(size); + if (!buffer) + return -ENOMEM; + + /* Reset file position to beginning */ + if (lseek(fd, 0, SEEK_SET) < 0) { + ret =3D -errno; + goto out; + } + + ret =3D read_size(fd, buffer, size); + if (ret < 0) + goto out; + + if (memcmp(buffer, expected_data, size) !=3D 0) { + ret =3D 1; + goto out; + } + + ret =3D 0; + +out: + free(buffer); + return ret; +} + +/* + * Verify fd content using mmap. Returns 0 on success, 1 on data mismatch, + * -errno on error. + */ +int verify_fd_content_mmap(int fd, const char *expected_data, size_t size) +{ + char *mapped_mem; + int ret; + + mapped_mem =3D mmap(NULL, size, PROT_READ, MAP_SHARED, fd, 0); + if (mapped_mem =3D=3D MAP_FAILED) + return -errno; + + ret =3D memcmp(mapped_mem, expected_data, size) ? 1 : 0; + munmap(mapped_mem, size); + return ret; +} + int luo_open_device(void) { return open(LUO_DEVICE, O_RDWR); diff --git a/tools/testing/selftests/liveupdate/luo_test_utils.h b/tools/te= sting/selftests/liveupdate/luo_test_utils.h index 90099bf49577..a69dce2649b0 100644 --- a/tools/testing/selftests/liveupdate/luo_test_utils.h +++ b/tools/testing/selftests/liveupdate/luo_test_utils.h @@ -35,6 +35,16 @@ void restore_and_read_stage(int state_session_fd, int to= ken, int *stage); =20 void daemonize_and_wait(void); =20 +int cwd_is_tmpfs(void); +int read_size(int fd, char *buffer, size_t size); +int write_size(int fd, const char *buffer, size_t size); +int generate_random_data(char *buffer, size_t size); +int save_test_data(const char *filename, const char *buffer, size_t size); +int load_test_data(const char *filename, char *buffer, size_t size); +int create_random_memfd(const char *memfd_name, char *buffer, size_t size); +int verify_fd_content_read(int fd, const char *expected_data, size_t size); +int verify_fd_content_mmap(int fd, const char *expected_data, size_t size); + typedef void (*luo_test_stage1_fn)(int luo_fd); typedef void (*luo_test_stage2_fn)(int luo_fd, int state_session_fd); =20 --=20 2.53.0.1213.gd9a14994de-goog From nobody Thu Apr 9 11:15:04 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 110423A875E; Sat, 4 Apr 2026 10:25:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298310; cv=none; b=ZpAOAu3gbUUWAhzYZT6IhOyRbBUDjnbU/6Us55SC0TUBxGANPATfAIQcnvVsondiLBaJkr0R8eBHoeNjTqL/qR/LbsYObJX18SltOYd3hQaW9vG/Y0K1hzrvMsuddLwo/2hJtOsRjhhIbNbNSvfjaF/E1cGjHjiYaU3WCYins1c= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298310; c=relaxed/simple; bh=jO6gii86DPoGXE2I2GMdnsjc79+Mrmki6SEokudViyo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rmF6ux3+NL5uge88IEBGwkpRmXiN7pT2DcWySldL223bAGfYvxcsIsWS5DoeYdz49g/s0duspa2Am41S23nEUURL87uc4Eow/tK5NkXNj+6L0RL3FLy2dF2H6Cv1AOJnggwEGaRUiL4IELX2capvDpa2Eu94jTGR3J4BevTsaIw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fkrLgO58; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="fkrLgO58" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BDF7BC19421; Sat, 4 Apr 2026 10:25:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775298309; bh=jO6gii86DPoGXE2I2GMdnsjc79+Mrmki6SEokudViyo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=fkrLgO58PB06qWQQJ4nhbCHIYS3eol7n2ImQc8zSS7GL1MFFSi/ShO+dzK3Ea+dCw XgOxyYoC35yO6hdYUdkndpKG6JcbD9eU8Jdg4IinA7vGzwxh7dk+qWzFo8NxM4E03P mOZtX6UjGrASHvgbsdeiTJZjbwgeZnGQ9smw4ErGAXJbrCQlPXvqcPuRj0Sd9tvIkU M2Kd1BVwOCDPV1mMS0GC47dCdboiHehCwwKWcq0ykc93iBPTmeZ219FmQtEu5DZe0L 9SyelQOQrCZMVtwsn3Wemrfb0K06JIcoJG5mvHtHcMRbmtM+2cjLaHZihLUfom61vh k7k1qp1zFK+0w== From: Pratyush Yadav To: Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Shuah Khan , Andrew Morton , Usama Arif Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 3/6] selftests/liveupdate: add test for memfd content preservation Date: Sat, 4 Apr 2026 10:24:46 +0000 Message-ID: <20260404102452.4091740-4-pratyush@kernel.org> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog In-Reply-To: <20260404102452.4091740-1-pratyush@kernel.org> References: <20260404102452.4091740-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Pratyush Yadav (Google)" Add a selftest that makes sure the contents of a memfd are correctly preserved across a live update. In stage 1, create a memfd and fill it with random data, and preserve it. Save the random data to the file system. This will be used by stage 2 to verify the contents are correct. In stage 2, retrieve the memfd and compare its contents with the contents saved on the file system. Signed-off-by: Pratyush Yadav Signed-off-by: Pratyush Yadav (Google) --- tools/testing/selftests/liveupdate/Makefile | 1 + .../testing/selftests/liveupdate/luo_memfd.c | 80 +++++++++++++++++++ 2 files changed, 81 insertions(+) diff --git a/tools/testing/selftests/liveupdate/Makefile b/tools/testing/se= lftests/liveupdate/Makefile index 051daae55eec..8e2eb6500c07 100644 --- a/tools/testing/selftests/liveupdate/Makefile +++ b/tools/testing/selftests/liveupdate/Makefile @@ -13,6 +13,7 @@ TEST_FILES +=3D do_kexec.sh include ../lib.mk =20 CFLAGS +=3D $(KHDR_INCLUDES) +CFLAGS +=3D -I$(top_srcdir)/tools/include CFLAGS +=3D -Wall -O2 -Wno-unused-function CFLAGS +=3D -MD =20 diff --git a/tools/testing/selftests/liveupdate/luo_memfd.c b/tools/testing= /selftests/liveupdate/luo_memfd.c index c1f3275963dc..068c7f30c4de 100644 --- a/tools/testing/selftests/liveupdate/luo_memfd.c +++ b/tools/testing/selftests/liveupdate/luo_memfd.c @@ -3,6 +3,9 @@ /* * Copyright (c) 2026, Google LLC. * Pratyush Yadav (Google) + * + * Copyright (C) 2025 Amazon.com Inc. or its affiliates. + * Pratyush Yadav */ =20 /* @@ -11,11 +14,14 @@ =20 #include #include +#include #include #include +#include #include =20 #include +#include =20 #include "../kselftest.h" #include "../kselftest_harness.h" @@ -25,9 +31,83 @@ #define STATE_SESSION_NAME "luo-state" #define STATE_MEMFD_TOKEN 1 =20 +#define MEMFD_DATA_SESSION_NAME "memfd_data_session" +#define MEMFD_DATA_TOKEN 1 +#define MEMFD_DATA_BUFFER_SIZE SZ_1M +#define MEMFD_DATA_FS_COPY "memfd_data_fs_copy.bin" + static int luo_fd =3D -1; static int stage; =20 +static void memfd_data_stage_1(struct __test_metadata *_metadata) +{ + int fd, session; + char *buffer; + struct liveupdate_session_preserve_fd preserve_arg =3D { .size =3D sizeof= (preserve_arg) }; + + buffer =3D malloc(MEMFD_DATA_BUFFER_SIZE); + ASSERT_NE(buffer, NULL); + + session =3D luo_create_session(luo_fd, MEMFD_DATA_SESSION_NAME); + ASSERT_GE(session, 0); + + fd =3D create_random_memfd("memfd_data", buffer, MEMFD_DATA_BUFFER_SIZE); + ASSERT_GE(fd, 0); + + ASSERT_EQ(save_test_data(MEMFD_DATA_FS_COPY, buffer, MEMFD_DATA_BUFFER_SI= ZE), 0); + + preserve_arg.fd =3D fd; + preserve_arg.token =3D MEMFD_DATA_TOKEN; + ASSERT_GE(ioctl(session, LIVEUPDATE_SESSION_PRESERVE_FD, &preserve_arg), = 0); + + daemonize_and_wait(); +} + +static void memfd_data_stage_2(struct __test_metadata *_metadata) +{ + int fd, session; + char *buffer; + struct liveupdate_session_retrieve_fd retrieve_arg =3D { .size =3D sizeof= (retrieve_arg) }; + + buffer =3D malloc(MEMFD_DATA_BUFFER_SIZE); + ASSERT_NE(buffer, NULL); + + session =3D luo_retrieve_session(luo_fd, MEMFD_DATA_SESSION_NAME); + ASSERT_GE(session, 0); + + ASSERT_EQ(load_test_data(MEMFD_DATA_FS_COPY, buffer, MEMFD_DATA_BUFFER_SI= ZE), 0); + + retrieve_arg.token =3D MEMFD_DATA_TOKEN; + ASSERT_GE(ioctl(session, LIVEUPDATE_SESSION_RETRIEVE_FD, &retrieve_arg), = 0); + fd =3D retrieve_arg.fd; + ASSERT_GE(fd, 0); + + ASSERT_EQ(verify_fd_content_read(fd, buffer, MEMFD_DATA_BUFFER_SIZE), 0); + + ASSERT_EQ(luo_session_finish(session), 0); +} + +/* + * Test that a memfd with its data is preserved across live update. + */ +TEST(memfd_data) +{ + if (cwd_is_tmpfs()) + SKIP(return, "test saves data to rootfs, cannot run on tmpfs"); + + switch (stage) { + case 1: + memfd_data_stage_1(_metadata); + break; + case 2: + memfd_data_stage_2(_metadata); + break; + default: + TH_LOG("Unknown stage %d\n", stage); + ASSERT_FALSE(true); + } +} + int main(int argc, char *argv[]) { int expected_stage =3D 0; --=20 2.53.0.1213.gd9a14994de-goog From nobody Thu Apr 9 11:15:04 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3D1C93A9D9B; 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dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZYQ7ubCn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 061D2C19423; Sat, 4 Apr 2026 10:25:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775298311; bh=yhc+rjmZS+/ri4F15AH1UIS3IbQVJpGORk0EnBOsrJ0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ZYQ7ubCnRVb1epQcNt1j443bvLWxuikT4iUFsiuU46MIoNMeVgLQML0zWXDSzi/KX lqPxpdpMEUS7GtjMImivTxeJxMBNqikNRC5Ob9svWrFDvSDnIE5ZKLV+m0Hm/uIloc RMNIVj06ugYvwWO4ZQudVD6r3dISz3lxvpRzRLQk2gSUYbPSIHVhVl/LO4eB+baiY7 vLYFjeqIjVnO8urGjlAMtQuoHUZp46a1JLsx38hgFbPlmjPOGnZ3xePH6ezBI+AoAr OKw/KzWXDsyVjDAfaimZD42Fx8eY59/n25MAbWO4lGJX5qHLFuTVSGzO4HFtMY4nmA vg4epi0k04JTQ== From: Pratyush Yadav To: Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Shuah Khan , Andrew Morton , Usama Arif Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 4/6] selftests/liveupdate: add test for zero-size memfd preservation Date: Sat, 4 Apr 2026 10:24:47 +0000 Message-ID: <20260404102452.4091740-5-pratyush@kernel.org> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog In-Reply-To: <20260404102452.4091740-1-pratyush@kernel.org> References: <20260404102452.4091740-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Pratyush Yadav (Google)" A zero-size memfd is a special case of memfd preservation. It takes a different path from normal both during preservation and during restore. In the serialization structure, the number of folios is zero and the vmalloc array with folios is empty. The restore logic should check for this and make sure to not touch the invalid array. Add a test to make sure this path works as expected. In stage 1, the test creates and preserves a memfd without any data. In stage 2, the test retrieves the memfd and makes sure it is still without data. Reviewed-by: Mike Rapoport (Microsoft) Signed-off-by: Pratyush Yadav (Google) --- .../testing/selftests/liveupdate/luo_memfd.c | 57 +++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/tools/testing/selftests/liveupdate/luo_memfd.c b/tools/testing= /selftests/liveupdate/luo_memfd.c index 068c7f30c4de..2889a21523fd 100644 --- a/tools/testing/selftests/liveupdate/luo_memfd.c +++ b/tools/testing/selftests/liveupdate/luo_memfd.c @@ -36,6 +36,9 @@ #define MEMFD_DATA_BUFFER_SIZE SZ_1M #define MEMFD_DATA_FS_COPY "memfd_data_fs_copy.bin" =20 +#define ZERO_SESSION_NAME "zero_session" +#define ZERO_MEMFD_TOKEN 1 + static int luo_fd =3D -1; static int stage; =20 @@ -108,6 +111,60 @@ TEST(memfd_data) } } =20 +static void zero_memfd_stage_1(struct __test_metadata *_metadata) +{ + int zero_fd, session; + struct liveupdate_session_preserve_fd preserve_arg =3D { .size =3D sizeof= (preserve_arg) }; + + session =3D luo_create_session(luo_fd, ZERO_SESSION_NAME); + ASSERT_GE(session, 0); + + zero_fd =3D memfd_create("zero_memfd", 0); + ASSERT_GE(zero_fd, 0); + + preserve_arg.fd =3D zero_fd; + preserve_arg.token =3D ZERO_MEMFD_TOKEN; + ASSERT_GE(ioctl(session, LIVEUPDATE_SESSION_PRESERVE_FD, &preserve_arg), = 0); + + daemonize_and_wait(); +} + +static void zero_memfd_stage_2(struct __test_metadata *_metadata) +{ + int zero_fd, session; + struct liveupdate_session_retrieve_fd retrieve_arg =3D { .size =3D sizeof= (retrieve_arg) }; + + session =3D luo_retrieve_session(luo_fd, ZERO_SESSION_NAME); + ASSERT_GE(session, 0); + + retrieve_arg.token =3D ZERO_MEMFD_TOKEN; + ASSERT_GE(ioctl(session, LIVEUPDATE_SESSION_RETRIEVE_FD, &retrieve_arg), = 0); + zero_fd =3D retrieve_arg.fd; + ASSERT_GE(zero_fd, 0); + + ASSERT_EQ(lseek(zero_fd, 0, SEEK_END), 0); + + ASSERT_EQ(luo_session_finish(session), 0); +} + +/* + * Test that a zero-sized memfd is preserved across live update. + */ +TEST(zero_memfd) +{ + switch (stage) { + case 1: + zero_memfd_stage_1(_metadata); + break; + case 2: + zero_memfd_stage_2(_metadata); + break; + default: + TH_LOG("Unknown stage %d\n", stage); + ASSERT_FALSE(true); + } +} + int main(int argc, char *argv[]) { int expected_stage =3D 0; --=20 2.53.0.1213.gd9a14994de-goog From nobody Thu Apr 9 11:15:04 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 497AC3A9D9C; Sat, 4 Apr 2026 10:25:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298314; cv=none; b=UV8guYlS97kXg4TKxTrQNXcsK+sj0mMWQrKfQyB8cr7KrrKJWyEkIV9uQrJguckONS1glTgJ+PSn+nhF0Kvf5UTpWkVUSepQahWeK8KHpYnUIW54c1+oECtty0+Y1y5mIR80pKabZv2PhVGoYP4J9pqrDhHMYsu6xIj1NbD+Q7k= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298314; c=relaxed/simple; bh=JfLttArZOADtfi5TGZ0YNDYHW3nPoKjJ1lSo350PlLs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=HiBHdjOeQXxU55wBZuN695LdgBIWUKDt0Tj0LCpJtyEtJTHQrrNkQOVrYwrtEI/cmLDqJlWG7pbSD6RkbaeMj+31IYZ9J57U/lmjrZaI9syp4ryM/7LZM4ON2y1D4nUtLKjq0myaQoJhgKqEpGmXmqEj24nMmjzDTuWVcZwGW8Y= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=LU4xdOV0; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="LU4xdOV0" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4202AC2BCAF; Sat, 4 Apr 2026 10:25:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775298314; bh=JfLttArZOADtfi5TGZ0YNDYHW3nPoKjJ1lSo350PlLs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LU4xdOV06IMSDczZpzEpiO/sssF/KovagN6uuJsWEJEOtmpk0im6gHS5tDVGSjFHX FB75OF+rYDWTr2D1DLz/yLtcUcAk16Dq4g1hO9WSLskBQ3vv1bn9t49uWq6BcBpRXL VDD4aDUu8vs4Li8OtsFWjL6ZwWfTpmUBPJyJlU9yyfYEAOUk+0U3yT7YK2Geu1w0gq vZfCqClXMHnoLlt2PMm+rykqOgYx2o1wOqpGVLAh3+su+bJiD2sC9RU5hTjGldmDG5 TuBa/R36+4OcxHu1GzI3bckMwYQ4dyE/nr7612/dajhw5uJCemaaQ6ImoRIDYuQNff QBjo9/IDOO1qA== From: Pratyush Yadav To: Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Shuah Khan , Andrew Morton , Usama Arif Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 5/6] selftests/liveupdate: add test for operations on a preserved memfd Date: Sat, 4 Apr 2026 10:24:48 +0000 Message-ID: <20260404102452.4091740-6-pratyush@kernel.org> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog In-Reply-To: <20260404102452.4091740-1-pratyush@kernel.org> References: <20260404102452.4091740-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Pratyush Yadav (Google)" Once a memfd is preserved, certain operations are not allowed to succeed since they might make the state of the memfd inconsistent with the serialized state. Among these operations are truncating or growing the memfd. Writes and reads to already existing memfd should succeed. Add a test that makes sure a preserved memfd does not allow growing or shrinking, but does allow reads and writes to existing memory to go thorough. Reviewed-by: Mike Rapoport (Microsoft) Signed-off-by: Pratyush Yadav Signed-off-by: Pratyush Yadav (Google) --- .../testing/selftests/liveupdate/luo_memfd.c | 57 +++++++++++++++++++ 1 file changed, 57 insertions(+) diff --git a/tools/testing/selftests/liveupdate/luo_memfd.c b/tools/testing= /selftests/liveupdate/luo_memfd.c index 2889a21523fd..661a7c922e9d 100644 --- a/tools/testing/selftests/liveupdate/luo_memfd.c +++ b/tools/testing/selftests/liveupdate/luo_memfd.c @@ -39,6 +39,10 @@ #define ZERO_SESSION_NAME "zero_session" #define ZERO_MEMFD_TOKEN 1 =20 +#define PRESERVED_SESSION_NAME "preserved_session" +#define PRESERVED_MEMFD_TOKEN 1 +#define PRESERVED_BUFFER_SIZE SZ_1M + static int luo_fd =3D -1; static int stage; =20 @@ -165,6 +169,59 @@ TEST(zero_memfd) } } =20 +/* + * Test that preserved memfd can't grow or shrink, but reads and writes st= ill + * work. + */ +TEST(preserved_ops) +{ + char write_buffer[128] =3D {'A'}; + int fd, session; + char *buffer; + struct liveupdate_session_preserve_fd preserve_arg =3D { .size =3D sizeof= (preserve_arg) }; + + if (stage !=3D 1) + SKIP(return, "test only expected to run on stage 1"); + + buffer =3D malloc(PRESERVED_BUFFER_SIZE); + ASSERT_NE(buffer, NULL); + + session =3D luo_create_session(luo_fd, PRESERVED_SESSION_NAME); + ASSERT_GE(session, 0); + + fd =3D create_random_memfd("preserved_memfd", buffer, PRESERVED_BUFFER_SI= ZE); + ASSERT_GE(fd, 0); + + preserve_arg.fd =3D fd; + preserve_arg.token =3D PRESERVED_MEMFD_TOKEN; + ASSERT_GE(ioctl(session, LIVEUPDATE_SESSION_PRESERVE_FD, &preserve_arg), = 0); + + /* + * Write to the preserved memfd (within existing size). This should + * work. + */ + ASSERT_GE(lseek(fd, 0, SEEK_SET), 0); + /* Write buffer is smaller than total file size. */ + ASSERT_EQ(write_size(fd, write_buffer, sizeof(write_buffer)), 0); + ASSERT_EQ(verify_fd_content_read(fd, write_buffer, sizeof(write_buffer)),= 0); + + /* Try to grow the file using write(). */ + + /* First, seek to one byte behind initial size. */ + ASSERT_GE(lseek(fd, PRESERVED_BUFFER_SIZE - 1, SEEK_SET), 0); + + /* + * Then, write some data that should increase the file size. This should + * fail. + */ + ASSERT_LT(write_size(fd, write_buffer, sizeof(write_buffer)), 0); + ASSERT_EQ(lseek(fd, 0, SEEK_END), PRESERVED_BUFFER_SIZE); + + /* Try to shrink the file using truncate. This should also fail. */ + ASSERT_LT(ftruncate(fd, PRESERVED_BUFFER_SIZE / 2), 0); + ASSERT_EQ(lseek(fd, 0, SEEK_END), PRESERVED_BUFFER_SIZE); +} + int main(int argc, char *argv[]) { int expected_stage =3D 0; --=20 2.53.0.1213.gd9a14994de-goog From nobody Thu Apr 9 11:15:04 2026 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 A010A3AA50B; Sat, 4 Apr 2026 10:25:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298316; cv=none; b=UIbXUuqjuMiCgf+R9RZQLcLQdMjo3nnusGp9+PTL2e9098Fzp4/nNAaPcUgqzJGUsBiSEXSOVtVe4gN9ruV0rtDN16VUlty7gDy9Qb90xlgWLPgK/YpIEdyhqkxpRM1dyHSC2FhVh3+/BX/RG28ARiswpxwNK1AEICJzdPhp30A= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1775298316; c=relaxed/simple; bh=HbTfOVPJ6K/pRH8J6grgNsnP9Mdw6sr2NEXeLDO74i4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=dUwSurdiXQePuJ4nNEERL3VIo+MKllA96nE7oTxuctrsLYLfjkGe8UgRcUj+e4hG2dTH5He9PR9pvWgWN4y3bk9iCGLwXAIpP0FgTZluFLdFgdSd1YorKFzIEKjuifR3VqIaJZPeuFJDtgFKZldvvxHJygaKZNVwk5ABBTfKsz0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=AhXhT4mL; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="AhXhT4mL" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7EC74C19425; Sat, 4 Apr 2026 10:25:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1775298316; bh=HbTfOVPJ6K/pRH8J6grgNsnP9Mdw6sr2NEXeLDO74i4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AhXhT4mLjF4Cf8C62FA/KA/9pEoCDE47gsVmIFBWLTITZCgMIKZDwQxCeMJRdFQMj 6DzWIngvuCeXyHjq+VYiAel/m4+T9MFxPuzN+qt+FBc1yHJ0A2xm5BKVz67jHyu64e nUfgw1V7azXDK8pTO8KL20Fn4FKyiNBlMZyuw7vSfuDfgosIxZw9sRQqlTxJHpTMSg mQvrxFhl2s615uwDAyhc0HbqI2yVMaz/uetKKnpkeoxFLF+VR0cTop5P0FCkmgpl8l rJbHS3S3ESSNJx+pV78/ntAZa3Abas8QBmDb0TXu0HjbaPA8Ge7qEDX0PSQd7GizcN ZIlyNzFx1kxTQ== From: Pratyush Yadav To: Pasha Tatashin , Mike Rapoport , Pratyush Yadav , Shuah Khan , Andrew Morton , Usama Arif Cc: linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v3 6/6] selftests/liveupdate: add fallocate test for memfd Date: Sat, 4 Apr 2026 10:24:49 +0000 Message-ID: <20260404102452.4091740-7-pratyush@kernel.org> X-Mailer: git-send-email 2.53.0.1213.gd9a14994de-goog In-Reply-To: <20260404102452.4091740-1-pratyush@kernel.org> References: <20260404102452.4091740-1-pratyush@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: "Pratyush Yadav (Google)" When memory is added to a memfd via fallocate(), it does not get zeroed immediately. This is tracked by the absence of the uptodate folio flag. Initially, memfd preservation simply saved the folio flags at preserve time. This led to a bug, where all writes to un-initialized fallocated memory after preserve were lost after live update. This is fixed by commit 50d7b4332f27 ("mm: memfd_luo: always make all folios uptodate"). Add a test that fallocates some memory in a memfd, preserves it, writes to it. Then in stage 2 it verifies the written content is still present. Reviewed-by: Mike Rapoport (Microsoft) Signed-off-by: Pratyush Yadav (Google) --- .../testing/selftests/liveupdate/luo_memfd.c | 83 +++++++++++++++++++ 1 file changed, 83 insertions(+) diff --git a/tools/testing/selftests/liveupdate/luo_memfd.c b/tools/testing= /selftests/liveupdate/luo_memfd.c index 661a7c922e9d..4a90044ecf1d 100644 --- a/tools/testing/selftests/liveupdate/luo_memfd.c +++ b/tools/testing/selftests/liveupdate/luo_memfd.c @@ -43,6 +43,11 @@ #define PRESERVED_MEMFD_TOKEN 1 #define PRESERVED_BUFFER_SIZE SZ_1M =20 +#define FALLOCATE_SESSION_NAME "fallocate_session" +#define FALLOCATE_MEMFD_TOKEN 1 +#define FALLOCATE_BUFFER_SIZE SZ_1M +#define FALLOCATE_DATA_FS_COPY "fallocate_data_fs_copy.bin" + static int luo_fd =3D -1; static int stage; =20 @@ -222,6 +227,84 @@ TEST(preserved_ops) ASSERT_EQ(lseek(fd, 0, SEEK_END), PRESERVED_BUFFER_SIZE); } =20 +static void fallocate_memfd_stage_1(struct __test_metadata *_metadata) +{ + int fd, session; + char *buffer; + struct liveupdate_session_preserve_fd preserve_arg =3D { .size =3D sizeof= (preserve_arg) }; + + buffer =3D malloc(FALLOCATE_BUFFER_SIZE); + ASSERT_NE(buffer, NULL); + + session =3D luo_create_session(luo_fd, FALLOCATE_SESSION_NAME); + ASSERT_GE(session, 0); + + fd =3D memfd_create("fallocate_memfd", 0); + ASSERT_GE(fd, 0); + + /* Fallocate memory but do not write to it yet */ + ASSERT_EQ(fallocate(fd, 0, 0, FALLOCATE_BUFFER_SIZE), 0); + + preserve_arg.fd =3D fd; + preserve_arg.token =3D FALLOCATE_MEMFD_TOKEN; + ASSERT_GE(ioctl(session, LIVEUPDATE_SESSION_PRESERVE_FD, &preserve_arg), = 0); + + /* Now write to it after preserving */ + ASSERT_GE(generate_random_data(buffer, FALLOCATE_BUFFER_SIZE), 0); + ASSERT_EQ(save_test_data(FALLOCATE_DATA_FS_COPY, buffer, FALLOCATE_BUFFER= _SIZE), 0); + + ASSERT_GE(lseek(fd, 0, SEEK_SET), 0); + ASSERT_EQ(write_size(fd, buffer, FALLOCATE_BUFFER_SIZE), 0); + + daemonize_and_wait(); +} + +static void fallocate_memfd_stage_2(struct __test_metadata *_metadata) +{ + int fd, session; + char *buffer; + struct liveupdate_session_retrieve_fd retrieve_arg =3D { .size =3D sizeof= (retrieve_arg) }; + + buffer =3D malloc(FALLOCATE_BUFFER_SIZE); + ASSERT_NE(buffer, NULL); + + session =3D luo_retrieve_session(luo_fd, FALLOCATE_SESSION_NAME); + ASSERT_GE(session, 0); + + ASSERT_EQ(load_test_data(FALLOCATE_DATA_FS_COPY, buffer, FALLOCATE_BUFFER= _SIZE), 0); + + retrieve_arg.token =3D FALLOCATE_MEMFD_TOKEN; + ASSERT_GE(ioctl(session, LIVEUPDATE_SESSION_RETRIEVE_FD, &retrieve_arg), = 0); + fd =3D retrieve_arg.fd; + ASSERT_GE(fd, 0); + + ASSERT_EQ(verify_fd_content_read(fd, buffer, FALLOCATE_BUFFER_SIZE), 0); + + ASSERT_EQ(luo_session_finish(session), 0); +} + +/* + * Test that an fallocated memfd is preserved across live update and can be + * written to after being preserved. + */ +TEST(fallocate_memfd) +{ + if (cwd_is_tmpfs()) + SKIP(return, "test saves data to rootfs, cannot run on tmpfs"); + + switch (stage) { + case 1: + fallocate_memfd_stage_1(_metadata); + break; + case 2: + fallocate_memfd_stage_2(_metadata); + break; + default: + TH_LOG("Unknown stage %d\n", stage); + ASSERT_FALSE(true); + } +} + int main(int argc, char *argv[]) { int expected_stage =3D 0; --=20 2.53.0.1213.gd9a14994de-goog