- Spectrum Development - spectrum-os.org

[REGRESSION] Cloud Hypervisor crashes when guest writes to VSOCK
by Alyssa Ross 24 Nov '25

24 Nov '25

This notably happens when an application that uses portals starts up and the org.freedesktop.impl.portal.desktop.spectrum D-Bus service is activated. Already fixed upstream in Cloud Hypervisor: https://github.com/cloud-hypervisor/cloud-hypervisor/pull/7477 Proposed a backport in Nixpkgs: https://github.com/NixOS/nixpkgs/pull/464618

1 0

[PATCH 1/3] tools/mount-flatpak: init
by Alyssa Ross 24 Nov '25

24 Nov '25

Signed-off-by: Alyssa Ross <hi(a)alyssa.is> --- LICENSES/MPL-2.0.txt | 373 ++++++++++++++++++++++++++++ tools/default.nix | 7 +- tools/meson.build | 1 + tools/mount-flatpak/config | 7 + tools/mount-flatpak/keyfile.rs | 189 ++++++++++++++ tools/mount-flatpak/meson.build | 18 ++ tools/mount-flatpak/metadata.h | 4 + tools/mount-flatpak/metadata.rs | 47 ++++ tools/mount-flatpak/mount-flatpak.c | 294 ++++++++++++++++++++++ 9 files changed, 938 insertions(+), 2 deletions(-) create mode 100644 LICENSES/MPL-2.0.txt create mode 100644 tools/mount-flatpak/config create mode 100644 tools/mount-flatpak/keyfile.rs create mode 100644 tools/mount-flatpak/meson.build create mode 100644 tools/mount-flatpak/metadata.h create mode 100644 tools/mount-flatpak/metadata.rs create mode 100644 tools/mount-flatpak/mount-flatpak.c diff --git a/LICENSES/MPL-2.0.txt b/LICENSES/MPL-2.0.txt new file mode 100644 index 0000000..d0a1fa1 --- /dev/null +++ b/LICENSES/MPL-2.0.txt @@ -0,0 +1,373 @@ +Mozilla Public License Version 2.0 +================================== + +1. Definitions +-------------- + +1.1. "Contributor" + means each individual or legal entity that creates, contributes to + the creation of, or owns Covered Software. + +1.2. "Contributor Version" + means the combination of the Contributions of others (if any) used + by a Contributor and that particular Contributor's Contribution. + +1.3. "Contribution" + means Covered Software of a particular Contributor. + +1.4. "Covered Software" + means Source Code Form to which the initial Contributor has attached + the notice in Exhibit A, the Executable Form of such Source Code + Form, and Modifications of such Source Code Form, in each case + including portions thereof. + +1.5. "Incompatible With Secondary Licenses" + means + + (a) that the initial Contributor has attached the notice described + in Exhibit B to the Covered Software; or + + (b) that the Covered Software was made available under the terms of + version 1.1 or earlier of the License, but not also under the + terms of a Secondary License. + +1.6. "Executable Form" + means any form of the work other than Source Code Form. + +1.7. "Larger Work" + means a work that combines Covered Software with other material, in + a separate file or files, that is not Covered Software. + +1.8. "License" + means this document. + +1.9. "Licensable" + means having the right to grant, to the maximum extent possible, + whether at the time of the initial grant or subsequently, any and + all of the rights conveyed by this License. + +1.10. "Modifications" + means any of the following: + + (a) any file in Source Code Form that results from an addition to, + deletion from, or modification of the contents of Covered + Software; or + + (b) any new file in Source Code Form that contains any Covered + Software. + +1.11. "Patent Claims" of a Contributor + means any patent claim(s), including without limitation, method, + process, and apparatus claims, in any patent Licensable by such + Contributor that would be infringed, but for the grant of the + License, by the making, using, selling, offering for sale, having + made, import, or transfer of either its Contributions or its + Contributor Version. + +1.12. "Secondary License" + means either the GNU General Public License, Version 2.0, the GNU + Lesser General Public License, Version 2.1, the GNU Affero General + Public License, Version 3.0, or any later versions of those + licenses. + +1.13. "Source Code Form" + means the form of the work preferred for making modifications. + +1.14. "You" (or "Your") + means an individual or a legal entity exercising rights under this + License. For legal entities, "You" includes any entity that + controls, is controlled by, or is under common control with You. For + purposes of this definition, "control" means (a) the power, direct + or indirect, to cause the direction or management of such entity, + whether by contract or otherwise, or (b) ownership of more than + fifty percent (50%) of the outstanding shares or beneficial + ownership of such entity. + +2. License Grants and Conditions +-------------------------------- + +2.1. Grants + +Each Contributor hereby grants You a world-wide, royalty-free, +non-exclusive license: + +(a) under intellectual property rights (other than patent or trademark) + Licensable by such Contributor to use, reproduce, make available, + modify, display, perform, distribute, and otherwise exploit its + Contributions, either on an unmodified basis, with Modifications, or + as part of a Larger Work; and + +(b) under Patent Claims of such Contributor to make, use, sell, offer + for sale, have made, import, and otherwise transfer either its + Contributions or its Contributor Version. + +2.2. Effective Date + +The licenses granted in Section 2.1 with respect to any Contribution +become effective for each Contribution on the date the Contributor first +distributes such Contribution. + +2.3. Limitations on Grant Scope + +The licenses granted in this Section 2 are the only rights granted under +this License. No additional rights or licenses will be implied from the +distribution or licensing of Covered Software under this License. +Notwithstanding Section 2.1(b) above, no patent license is granted by a +Contributor: + +(a) for any code that a Contributor has removed from Covered Software; + or + +(b) for infringements caused by: (i) Your and any other third party's + modifications of Covered Software, or (ii) the combination of its + Contributions with other software (except as part of its Contributor + Version); or + +(c) under Patent Claims infringed by Covered Software in the absence of + its Contributions. + +This License does not grant any rights in the trademarks, service marks, +or logos of any Contributor (except as may be necessary to comply with +the notice requirements in Section 3.4). + +2.4. Subsequent Licenses + +No Contributor makes additional grants as a result of Your choice to +distribute the Covered Software under a subsequent version of this +License (see Section 10.2) or under the terms of a Secondary License (if +permitted under the terms of Section 3.3). + +2.5. Representation + +Each Contributor represents that the Contributor believes its +Contributions are its original creation(s) or it has sufficient rights +to grant the rights to its Contributions conveyed by this License. + +2.6. Fair Use + +This License is not intended to limit any rights You have under +applicable copyright doctrines of fair use, fair dealing, or other +equivalents. + +2.7. Conditions + +Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted +in Section 2.1. + +3. Responsibilities +------------------- + +3.1. Distribution of Source Form + +All distribution of Covered Software in Source Code Form, including any +Modifications that You create or to which You contribute, must be under +the terms of this License. You must inform recipients that the Source +Code Form of the Covered Software is governed by the terms of this +License, and how they can obtain a copy of this License. You may not +attempt to alter or restrict the recipients' rights in the Source Code +Form. + +3.2. Distribution of Executable Form + +If You distribute Covered Software in Executable Form then: + +(a) such Covered Software must also be made available in Source Code + Form, as described in Section 3.1, and You must inform recipients of + the Executable Form how they can obtain a copy of such Source Code + Form by reasonable means in a timely manner, at a charge no more + than the cost of distribution to the recipient; and + +(b) You may distribute such Executable Form under the terms of this + License, or sublicense it under different terms, provided that the + license for the Executable Form does not attempt to limit or alter + the recipients' rights in the Source Code Form under this License. + +3.3. Distribution of a Larger Work + +You may create and distribute a Larger Work under terms of Your choice, +provided that You also comply with the requirements of this License for +the Covered Software. If the Larger Work is a combination of Covered +Software with a work governed by one or more Secondary Licenses, and the +Covered Software is not Incompatible With Secondary Licenses, this +License permits You to additionally distribute such Covered Software +under the terms of such Secondary License(s), so that the recipient of +the Larger Work may, at their option, further distribute the Covered +Software under the terms of either this License or such Secondary +License(s). + +3.4. Notices + +You may not remove or alter the substance of any license notices +(including copyright notices, patent notices, disclaimers of warranty, +or limitations of liability) contained within the Source Code Form of +the Covered Software, except that You may alter any license notices to +the extent required to remedy known factual inaccuracies. + +3.5. Application of Additional Terms + +You may choose to offer, and to charge a fee for, warranty, support, +indemnity or liability obligations to one or more recipients of Covered +Software. However, You may do so only on Your own behalf, and not on +behalf of any Contributor. You must make it absolutely clear that any +such warranty, support, indemnity, or liability obligation is offered by +You alone, and You hereby agree to indemnify every Contributor for any +liability incurred by such Contributor as a result of warranty, support, +indemnity or liability terms You offer. You may include additional +disclaimers of warranty and limitations of liability specific to any +jurisdiction. + +4. Inability to Comply Due to Statute or Regulation +--------------------------------------------------- + +If it is impossible for You to comply with any of the terms of this +License with respect to some or all of the Covered Software due to +statute, judicial order, or regulation then You must: (a) comply with +the terms of this License to the maximum extent possible; and (b) +describe the limitations and the code they affect. Such description must +be placed in a text file included with all distributions of the Covered +Software under this License. Except to the extent prohibited by statute +or regulation, such description must be sufficiently detailed for a +recipient of ordinary skill to be able to understand it. + +5. Termination +-------------- + +5.1. The rights granted under this License will terminate automatically +if You fail to comply with any of its terms. However, if You become +compliant, then the rights granted under this License from a particular +Contributor are reinstated (a) provisionally, unless and until such +Contributor explicitly and finally terminates Your grants, and (b) on an +ongoing basis, if such Contributor fails to notify You of the +non-compliance by some reasonable means prior to 60 days after You have +come back into compliance. Moreover, Your grants from a particular +Contributor are reinstated on an ongoing basis if such Contributor +notifies You of the non-compliance by some reasonable means, this is the +first time You have received notice of non-compliance with this License +from such Contributor, and You become compliant prior to 30 days after +Your receipt of the notice. + +5.2. If You initiate litigation against any entity by asserting a patent +infringement claim (excluding declaratory judgment actions, +counter-claims, and cross-claims) alleging that a Contributor Version +directly or indirectly infringes any patent, then the rights granted to +You by any and all Contributors for the Covered Software under Section +2.1 of this License shall terminate. + +5.3. In the event of termination under Sections 5.1 or 5.2 above, all +end user license agreements (excluding distributors and resellers) which +have been validly granted by You or Your distributors under this License +prior to termination shall survive termination. + +************************************************************************ +* * +* 6. Disclaimer of Warranty * +* ------------------------- * +* * +* Covered Software is provided under this License on an "as is" * +* basis, without warranty of any kind, either expressed, implied, or * +* statutory, including, without limitation, warranties that the * +* Covered Software is free of defects, merchantable, fit for a * +* particular purpose or non-infringing. The entire risk as to the * +* quality and performance of the Covered Software is with You. * +* Should any Covered Software prove defective in any respect, You * +* (not any Contributor) assume the cost of any necessary servicing, * +* repair, or correction. This disclaimer of warranty constitutes an * +* essential part of this License. No use of any Covered Software is * +* authorized under this License except under this disclaimer. * +* * +************************************************************************ + +************************************************************************ +* * +* 7. Limitation of Liability * +* -------------------------- * +* * +* Under no circumstances and under no legal theory, whether tort * +* (including negligence), contract, or otherwise, shall any * +* Contributor, or anyone who distributes Covered Software as * +* permitted above, be liable to You for any direct, indirect, * +* special, incidental, or consequential damages of any character * +* including, without limitation, damages for lost profits, loss of * +* goodwill, work stoppage, computer failure or malfunction, or any * +* and all other commercial damages or losses, even if such party * +* shall have been informed of the possibility of such damages. This * +* limitation of liability shall not apply to liability for death or * +* personal injury resulting from such party's negligence to the * +* extent applicable law prohibits such limitation. Some * +* jurisdictions do not allow the exclusion or limitation of * +* incidental or consequential damages, so this exclusion and * +* limitation may not apply to You. * +* * +************************************************************************ + +8. Litigation +------------- + +Any litigation relating to this License may be brought only in the +courts of a jurisdiction where the defendant maintains its principal +place of business and such litigation shall be governed by laws of that +jurisdiction, without reference to its conflict-of-law provisions. +Nothing in this Section shall prevent a party's ability to bring +cross-claims or counter-claims. + +9. Miscellaneous +---------------- + +This License represents the complete agreement concerning the subject +matter hereof. If any provision of this License is held to be +unenforceable, such provision shall be reformed only to the extent +necessary to make it enforceable. Any law or regulation which provides +that the language of a contract shall be construed against the drafter +shall not be used to construe this License against a Contributor. + +10. Versions of the License +--------------------------- + +10.1. New Versions + +Mozilla Foundation is the license steward. Except as provided in Section +10.3, no one other than the license steward has the right to modify or +publish new versions of this License. Each version will be given a +distinguishing version number. + +10.2. Effect of New Versions + +You may distribute the Covered Software under the terms of the version +of the License under which You originally received the Covered Software, +or under the terms of any subsequent version published by the license +steward. + +10.3. Modified Versions + +If you create software not governed by this License, and you want to +create a new license for such software, you may create and use a +modified version of this License if you rename the license and remove +any references to the name of the license steward (except to note that +such modified license differs from this License). + +10.4. Distributing Source Code Form that is Incompatible With Secondary +Licenses + +If You choose to distribute Source Code Form that is Incompatible With +Secondary Licenses under the terms of this version of the License, the +notice described in Exhibit B of this License must be attached. + +Exhibit A - Source Code Form License Notice +------------------------------------------- + + This Source Code Form is subject to the terms of the Mozilla Public + License, v. 2.0. If a copy of the MPL was not distributed with this + file, You can obtain one at https://mozilla.org/MPL/2.0/. + +If it is not possible or desirable to put the notice in a particular +file, then You may include the notice in a location (such as a LICENSE +file in a relevant directory) where a recipient would be likely to look +for such a notice. + +You may add additional accurate notices of copyright ownership. + +Exhibit B - "Incompatible With Secondary Licenses" Notice +--------------------------------------------------------- + + This Source Code Form is "Incompatible With Secondary Licenses", as + defined by the Mozilla Public License, v. 2.0. diff --git a/tools/default.nix b/tools/default.nix index 27d4b82..27741b3 100644 --- a/tools/default.nix +++ b/tools/default.nix @@ -74,6 +74,7 @@ stdenv.mkDerivation (finalAttrs: { ./xdg-desktop-portal-spectrum ] ++ lib.optionals hostSupport [ ./lsvm + ./mount-flatpak ./sd-notify-adapter.c ./start-vmm ./subprojects @@ -88,8 +89,10 @@ stdenv.mkDerivation (finalAttrs: { ++ lib.optionals (appSupport || driverSupport) [ pkg-config ] ++ lib.optionals hostSupport [ rustc ] ++ lib.optionals driverSupport [ llvmPackages.clang-unwrapped ]; - buildInputs = lib.optionals appSupport [ dbus ] - ++ lib.optionals driverSupport [ libbpf linuxHeaders ]; + buildInputs = with stdenv.hostPlatform; lib.optionals appSupport [ dbus ] + ++ lib.optionals driverSupport [ libbpf linuxHeaders ] + # Workaround for <https://github.com/mesonbuild/meson/pull/15216>. + ++ lib.optionals (hostSupport && isMusl && isStatic) [ llvmPackages.libunwind ]; postPatch = lib.optionals hostSupport (lib.concatMapStringsSep "\n" (crate: '' mkdir -p subprojects/packagecache diff --git a/tools/meson.build b/tools/meson.build index d465e99..c024ca6 100644 --- a/tools/meson.build +++ b/tools/meson.build @@ -30,6 +30,7 @@ if get_option('host') install: true) subdir('lsvm') + subdir('mount-flatpak') subdir('start-vmm') endif diff --git a/tools/mount-flatpak/config b/tools/mount-flatpak/config new file mode 100644 index 0000000..b3c2bee --- /dev/null +++ b/tools/mount-flatpak/config @@ -0,0 +1,7 @@ +# SPDX-License-Identifier: CC0-1.0 +# SPDX-FileCopyrightText: 2025 Alyssa Ross <hi(a)alyssa.is> + +[core] +repo_version=1 +mode=bare-user-only +min-free-space-size=500MB diff --git a/tools/mount-flatpak/keyfile.rs b/tools/mount-flatpak/keyfile.rs new file mode 100644 index 0000000..fa746b3 --- /dev/null +++ b/tools/mount-flatpak/keyfile.rs @@ -0,0 +1,189 @@ +// Copyright 2021 System76 <info(a)system76.com> +// SPDX-FileCopyrightText: 2025 Alyssa Ross <hi(a)alyssa.is> +// SPDX-License-Identifier: MPL-2.0 + +// Adapted from freedesktop-desktop-entry 0.7.19. + +use std::collections::BTreeMap; +use std::fmt::{self, Display, Formatter}; + +type Group = BTreeMap<String, String>; + +#[derive(Debug)] +pub enum DecodeError { + KeyValueWithoutAGroup, + InvalidKey, + InvalidValue, +} + +impl Display for DecodeError { + fn fmt(&self, f: &mut Formatter) -> fmt::Result { + match self { + Self::KeyValueWithoutAGroup => write!(f, "key/value without a group"), + Self::InvalidKey => write!(f, "invalid key"), + Self::InvalidValue => write!(f, "invalid value"), + } + } +} + +pub fn parse(input: &str) -> Result<BTreeMap<String, Group>, DecodeError> { + let mut groups = BTreeMap::default(); + let mut active_group: Option<ActiveGroup> = None; + let mut active_keys: Option<ActiveKeys> = None; + + for line in input.lines() { + process_line(line, &mut groups, &mut active_group, &mut active_keys)?; + } + + if let Some(active_keys) = active_keys.take() { + match &mut active_group { + Some(active_group) => { + active_group + .group + .insert(active_keys.key_name, active_keys.value); + } + None => return Err(DecodeError::KeyValueWithoutAGroup), + } + } + + if let Some(mut group) = active_group.take() { + groups + .entry(group.group_name) + .or_default() + .append(&mut group.group); + } + + Ok(groups) +} + +struct ActiveGroup { + group_name: String, + group: Group, +} + +struct ActiveKeys { + key_name: String, + value: String, +} + +#[inline(never)] +fn process_line( + line: &str, + groups: &mut BTreeMap<String, Group>, + active_group: &mut Option<ActiveGroup>, + active_keys: &mut Option<ActiveKeys>, +) -> Result<(), DecodeError> { + if line.trim().is_empty() || line.starts_with('#') { + return Ok(()); + } + + let line_bytes = line.as_bytes(); + + // if group + if line_bytes[0] == b'[' { + if let Some(end) = line_bytes[1..].iter().rposition(|&b| b == b']') { + let group_name = &line[1..end + 1]; + + if let Some(active_keys) = active_keys.take() { + match active_group { + Some(active_group) => { + active_group + .group + .insert(active_keys.key_name, active_keys.value); + } + None => return Err(DecodeError::KeyValueWithoutAGroup), + } + } + + if let Some(mut group) = active_group.take() { + groups + .entry(group.group_name) + .or_default() + .append(&mut group.group); + } + + active_group.replace(ActiveGroup { + group_name: group_name.to_string(), + group: Group::default(), + }); + } + } + // else, if value + else if let Some(delimiter) = line_bytes.iter().position(|&b| b == b'=') { + let key = &line[..delimiter]; + let value = format_value(&line[delimiter + 1..])?; + + if key.is_empty() { + return Err(DecodeError::InvalidKey); + } + + if let Some(active_keys) = active_keys.take() { + match active_group { + Some(active_group) => { + active_group + .group + .insert(active_keys.key_name, active_keys.value); + } + None => return Err(DecodeError::KeyValueWithoutAGroup), + } + } + active_keys.replace(ActiveKeys { + key_name: key.trim().to_string(), + value, + }); + } + Ok(()) +} + +// https://specifications.freedesktop.org/desktop-entry-spec/latest/value-type… +#[inline] +fn format_value(input: &str) -> Result<String, DecodeError> { + let input = if let Some(input) = input.strip_prefix(" ") { + input + } else { + input + }; + + let mut res = String::with_capacity(input.len()); + + let mut last: usize = 0; + + for (i, v) in input.as_bytes().iter().enumerate() { + if *v != b'\\' { + continue; + } + + // edge case for // + if last > i { + continue; + } + + // when there is an \ at the end + if input.len() <= i + 1 { + return Err(DecodeError::InvalidValue); + } + + if last < i { + res.push_str(&input[last..i]); + } + + last = i + 2; + + match input.as_bytes()[i + 1] { + b's' => res.push(' '), + b'n' => res.push('\n'), + b't' => res.push('\t'), + b'r' => res.push('\r'), + b'\\' => res.push('\\'), + _ => { + return Err(DecodeError::InvalidValue); + } + } + } + + if last < input.len() { + res.push_str(&input[last..input.len()]); + } + + Ok(res) +} diff --git a/tools/mount-flatpak/meson.build b/tools/mount-flatpak/meson.build new file mode 100644 index 0000000..e0c0a85 --- /dev/null +++ b/tools/mount-flatpak/meson.build @@ -0,0 +1,18 @@ +# SPDX-License-Identifier: EUPL-1.2+ +# SPDX-FileCopyrightText: 2025 Alyssa Ross <hi(a)alyssa.is> + +rust_lib = static_library('metadata', 'metadata.rs', rust_abi : 'c') + +conf_data = configuration_data() +conf_data.set_quoted('CONFIG_PATH', + get_option('prefix') / get_option('datadir') / 'spectrum/flatpak-config') +configure_file(output : 'config.h', configuration : conf_data) + +executable('mount-flatpak', 'mount-flatpak.c', + c_args : '-D_GNU_SOURCE', + link_with : rust_lib, + install : true) + +install_data('config', + rename : 'flatpak-config', + install_dir : get_option('datadir') / 'spectrum') diff --git a/tools/mount-flatpak/metadata.h b/tools/mount-flatpak/metadata.h new file mode 100644 index 0000000..d6441b7 --- /dev/null +++ b/tools/mount-flatpak/metadata.h @@ -0,0 +1,4 @@ +// SPDX-License-Identifier: EUPL-1.2+ +// SPDX-FileCopyrightText: 2025 Alyssa Ross <hi(a)alyssa.is> + +void extract_runtime(int metadata, char *runtime); diff --git a/tools/mount-flatpak/metadata.rs b/tools/mount-flatpak/metadata.rs new file mode 100644 index 0000000..0398416 --- /dev/null +++ b/tools/mount-flatpak/metadata.rs @@ -0,0 +1,47 @@ +// SPDX-License-Identifier: EUPL-1.2+ +// SPDX-FileCopyrightText: 2025 Alyssa Ross <hi(a)alyssa.is> + +mod keyfile; + +use std::env::args_os; +use std::ffi::OsString; +use std::fs::File; +use std::io::{read_to_string, stderr, Write}; +use std::os::fd::OwnedFd; +use std::os::unix::prelude::*; +use std::process::exit; + +use keyfile::parse; + +fn extract_runtime(mut metadata: File) -> Result<String, String> { + let metadata = read_to_string(&mut metadata).map_err(|e| e.to_string())?; + let group = parse(&metadata).map_err(|e| e.to_string())?; + let application = group + .get("Application") + .ok_or_else(|| "Application group missing".to_string())?; + Ok(application + .get("runtime") + .ok_or_else(|| "runtime property missing".to_string())? + .clone()) +} + +// SAFETY: we do not expect "extract_runtime" to collide with another symbol. +#[unsafe(export_name = "extract_runtime")] +pub extern "C" fn extract_runtime_c(metadata: OwnedFd, out: &mut [u8; 256]) { + let error = match extract_runtime(metadata.into()) { + Err(e) => e, + Ok(runtime) if runtime.len() >= out.len() => "runtime name too long".to_string(), + Ok(runtime) => { + out[..runtime.len()].copy_from_slice(runtime.as_bytes()); + out[runtime.len()] = 0; + return; + } + }; + + let prog_name = args_os() + .next() + .unwrap_or_else(|| OsString::from("mount-flatpak")); + stderr().write_all(prog_name.as_bytes()).unwrap(); + eprintln!(": {error}"); + exit(1); +} diff --git a/tools/mount-flatpak/mount-flatpak.c b/tools/mount-flatpak/mount-flatpak.c new file mode 100644 index 0000000..8e09d1d --- /dev/null +++ b/tools/mount-flatpak/mount-flatpak.c @@ -0,0 +1,294 @@ +// SPDX-License-Identifier: EUPL-1.2+ +// SPDX-FileCopyrightText: 2025 Alyssa Ross <hi(a)alyssa.is> + +#include "config.h" +#include "metadata.h" + +#include <err.h> +#include <fcntl.h> +#include <stdlib.h> +#include <stdio.h> +#include <string.h> +#include <unistd.h> + +#include <sys/stat.h> +#include <sys/syscall.h> + +#include <linux/mount.h> +#include <linux/openat2.h> + +static void bind_mount(int source_fd, const char *source, + int target_fd, const char *target) +{ + int source_tree = syscall(SYS_open_tree, source_fd, source, + AT_EMPTY_PATH | OPEN_TREE_CLOEXEC | + OPEN_TREE_CLONE | AT_RECURSIVE); + + if (source_tree == -1) + err(EXIT_FAILURE, "open_tree %s", source); + if (syscall(SYS_move_mount, source_tree, "", target_fd, target, + MOVE_MOUNT_F_EMPTY_PATH | MOVE_MOUNT_T_EMPTY_PATH) == -1) + err(EXIT_FAILURE, "move_mount"); +} + +static int mkdir_openat(int dirfd, const char *path, mode_t mode) +{ + int fd; + if (mkdirat(dirfd, path, mode) == -1) + err(EXIT_FAILURE, "mkdirat %s", path); + if ((fd = openat(dirfd, path, O_PATH | O_DIRECTORY | O_CLOEXEC)) == -1) + err(EXIT_FAILURE, "openat %s", path); + return fd; +} + +// By failing on EEXIST when creating each directory, +// we can be sure we don't end up following .. components. +static int mkdirs_beneath(int root, const char *target) +{ + int last, fd = root; + size_t len = strlen(target); + char *end, *path = malloc(len + 1), *dir = path; + if (!dir) + err(EXIT_FAILURE, "malloc %zu", len + 1); + memcpy(dir, target, len + 1); + + do { + // Find next non-empty directory component + end = strchrnul(dir, '/'); + while (*(end + 1) == '/') + end++; + + // Replace path separator with string terminator. + *end = 0; + + // Update fd to a new child, and close the previous one + // unless it was the one provided by the caller. + last = fd; + fd = mkdir_openat(fd, dir, 0755); + if (last != root) + close(last); + + dir = end + 1; + } while (end != &path[len]); + + free(path); + return fd; +} + +static int openat_beneath(int dirfd, const char *path, int flags) +{ + struct open_how how = { + .flags = flags, + .resolve = RESOLVE_BENEATH | RESOLVE_NO_MAGICLINKS, + }; + int r = syscall(SYS_openat2, dirfd, path, &how, sizeof how); + if (r == -1) + err(EXIT_FAILURE, "openat2 %s", path); + return r; +} + +static int resolve_link(int dirfd, const char *path, char **target) +{ + int r; + struct stat sb; + if (fstatat(dirfd, path, &sb, AT_SYMLINK_NOFOLLOW) == -1) + err(EXIT_FAILURE, "fstatat %s", path); + if (!(*target = malloc(sb.st_size + 1))) + err(EXIT_FAILURE, "malloc %zu", sb.st_size + 1); + if ((r = readlinkat(dirfd, path, *target, sb.st_size + 1)) <= -1) + err(EXIT_FAILURE, "readlinkat %s", path); + if (r == sb.st_size + 1) + errx(EXIT_FAILURE, "symlink target lengthened"); + (*target)[r] = 0; // NOLINT(clang-analyzer-security.ArrayBound) + return openat_beneath(dirfd, *target, O_PATH | O_CLOEXEC | O_DIRECTORY); +} + +static void write_to(int dirfd, const char *path, const char *text) +{ + FILE *file; + size_t len = strlen(text); + int f = openat(dirfd, path, + O_WRONLY | O_CLOEXEC | O_NOFOLLOW | O_CREAT, 0644); + + if (f == -1) + err(EXIT_FAILURE, "openat %s", path); + if (!(file = fdopen(f, "w"))) + err(EXIT_FAILURE, "fdopen %s", path); + + if (fwrite(text, 1, len, file) != len) + err(EXIT_FAILURE, "fwrite"); + if (fclose(file) == EOF) + err(EXIT_FAILURE, "fclose"); +} + +static void set_up_app_dir(int source_commit_dir, int installation_dir, + const char *id, const char *arch, + const char *branch, const char *commit) +{ + int app_dir, id_dir, arch_dir, branch_dir; + + app_dir = mkdir_openat(installation_dir, "app", 0755); + + id_dir = mkdir_openat(app_dir, id, 0755); + close(app_dir); + + arch_dir = mkdir_openat(id_dir, arch, 0755); + close(id_dir); + + branch_dir = mkdir_openat(arch_dir, branch, 0755); + close(arch_dir); + + if (mkdirat(branch_dir, commit, 0755) == -1) + err(EXIT_FAILURE, "mkdirat %s", commit); + bind_mount(source_commit_dir, "", branch_dir, commit); + close(branch_dir); +} + +static int mount_app(int source_installation_dir, int target_installation_dir, + int params_dir, const char *id) +{ + char *arch_and_branch, *arch_end, *commit; + int app_dir, id_dir, branch_dir, commit_dir; + + app_dir = openat_beneath(source_installation_dir, "app", + O_PATH | O_CLOEXEC | O_DIRECTORY); + id_dir = openat_beneath(app_dir, id, O_PATH | O_CLOEXEC | O_DIRECTORY); + close(app_dir); + + branch_dir = resolve_link(id_dir, "current", &arch_and_branch); + close(id_dir); + + commit_dir = resolve_link(branch_dir, "active", &commit); + close(branch_dir); + + if (!(arch_end = strchr(arch_and_branch, '/'))) + errx(EXIT_FAILURE, "unexpected current format"); + *arch_end = 0; + + set_up_app_dir(commit_dir, target_installation_dir, id, + arch_and_branch, arch_end + 1, commit); + write_to(params_dir, "commit", commit); + write_to(params_dir, "arch", arch_and_branch); + write_to(params_dir, "branch", arch_end + 1); + + free(arch_and_branch); + free(commit); + return commit_dir; +} + +static void set_up_runtime_dir(int source_commit_dir, int installation_dir, + const char *ref, const char *commit) +{ + int runtime_dir, branch_dir; + + runtime_dir = mkdir_openat(installation_dir, "runtime", 0755); + + branch_dir = mkdirs_beneath(runtime_dir, ref); + close(runtime_dir); + + if (mkdirat(branch_dir, commit, 0755) == -1) + err(EXIT_FAILURE, "mkdirat %s", commit); + bind_mount(source_commit_dir, "", branch_dir, commit); + close(branch_dir); +} + +static void mount_runtime(int source_installation_dir, + int target_installation_dir, + int params_dir, int app_commit_dir) +{ + char runtime[256], *commit; + int runtime_dir, branch_dir, commit_dir; + int metadata = openat_beneath(app_commit_dir, "metadata", + O_RDONLY | O_CLOEXEC); + + extract_runtime(metadata, runtime); + + runtime_dir = openat_beneath(source_installation_dir, "runtime", + O_PATH | O_CLOEXEC | O_DIRECTORY); + + branch_dir = openat_beneath(runtime_dir, runtime, + O_PATH | O_CLOEXEC | O_DIRECTORY); + close(runtime_dir); + + commit_dir = resolve_link(branch_dir, "active", &commit); + close(branch_dir); + + set_up_runtime_dir(commit_dir, target_installation_dir, + runtime, commit); + write_to(params_dir, "runtime-commit", commit); + + free(commit); + close(commit_dir); +} + +static void set_up_repo(int target_installation_dir) +{ + int config; + + if (mkdirat(target_installation_dir, "repo", 0755) == -1) + err(EXIT_FAILURE, "mkdir repo"); + if (mkdirat(target_installation_dir, "repo/objects", 0755) == -1) + err(EXIT_FAILURE, "mkdir repo/objects"); + if (mkdirat(target_installation_dir, "repo/tmp", 0775) == -1) + err(EXIT_FAILURE, "mkdir repo/tmp"); + if (mkdirat(target_installation_dir, "repo/tmp/cache", 0775) == -1) + err(EXIT_FAILURE, "mkdir repo/tmp/cache"); + + if ((config = openat(target_installation_dir, "repo/config", + O_WRONLY | O_CLOEXEC | O_NOFOLLOW | O_CREAT, + 0644)) == -1) + err(EXIT_FAILURE, "openat repo/config"); + + bind_mount(AT_FDCWD, CONFIG_PATH, config, ""); + + close(config); +} + +int main(int, char **argv) +{ + char *installation_path, *id; + int params_dir, source_installation_dir, target_installation_dir, + app_commit_dir; + struct mount_attr attr = { + .attr_clr = MOUNT_ATTR_NOSYMFOLLOW, + .attr_set = MOUNT_ATTR_RDONLY | MOUNT_ATTR_NODEV, + }; + + if (!(installation_path = *++argv)) + errx(EXIT_FAILURE, "missing installation path"); + if (!(id = *++argv)) + errx(EXIT_FAILURE, "missing app ID"); + + if ((source_installation_dir = open(installation_path, + O_PATH | O_CLOEXEC | O_DIRECTORY)) == -1) + err(EXIT_FAILURE, "open %s", installation_path); + + params_dir = mkdir_openat(AT_FDCWD, "params", 0755); + write_to(params_dir, "id", id); + + if (mkdir("flatpak", 0755) == -1) + err(EXIT_FAILURE, "mkdir flatpak"); + if ((target_installation_dir = syscall(SYS_open_tree, AT_FDCWD, + "flatpak", + AT_EMPTY_PATH | OPEN_TREE_CLONE | + OPEN_TREE_CLOEXEC | + AT_RECURSIVE)) == -1) + err(EXIT_FAILURE, "open_tree flatpak"); + + app_commit_dir = mount_app(source_installation_dir, + target_installation_dir, params_dir, id); + mount_runtime(source_installation_dir, target_installation_dir, + params_dir, app_commit_dir); + close(source_installation_dir); + close(params_dir); + + set_up_repo(target_installation_dir); + + if (syscall(SYS_mount_setattr, target_installation_dir, "", + AT_EMPTY_PATH | AT_RECURSIVE, &attr, sizeof attr) == -1) + err(EXIT_FAILURE, "mount_setattr flatpak"); + if (syscall(SYS_move_mount, target_installation_dir, "", + AT_FDCWD, "flatpak", MOVE_MOUNT_F_EMPTY_PATH) == -1) + err(EXIT_FAILURE, "move_mount flatpak flatpak"); + close(target_installation_dir); +} base-commit: 4b89596e112d26c4bd60bc46bb45c5d9a0875314 -- 2.51.0

2 11

[PATCH 1/3] img/app: move init to /usr/bin
by Alyssa Ross 18 Nov '25

18 Nov '25

/sbin/init (which for us is /usr/bin/init via the /sbin symlink) is the highest precedence path for init in the kernel. If we keep our init at /etc/init, installing a package (like systemd) that provides its own init will quietly take precedence over our own. Let's claim this path for ourselves, so adding init from a package will fail loudly. Signed-off-by: Alyssa Ross <hi(a)alyssa.is> --- img/app/file-list.mk | 4 ++-- img/app/image/{etc => usr/bin}/init | 0 2 files changed, 2 insertions(+), 2 deletions(-) rename img/app/image/{etc => usr/bin}/init (100%) diff --git a/img/app/file-list.mk b/img/app/file-list.mk index 506ab7a..0b4d3d1 100644 --- a/img/app/file-list.mk +++ b/img/app/file-list.mk @@ -4,7 +4,6 @@ FILES = \ image/etc/dbus-1/session.conf \ image/etc/fstab \ - image/etc/init \ image/etc/mdev.conf \ image/etc/mdev/iface \ image/etc/mdev/listen \ @@ -26,7 +25,8 @@ FILES = \ image/etc/s6-linux-init/scripts/rc.shutdown \ image/etc/s6-linux-init/scripts/rc.shutdown.final \ image/etc/wireplumber/wireplumber.conf.d/99_spectrum.conf \ - image/etc/xdg/xdg-desktop-portal/portals.conf + image/etc/xdg/xdg-desktop-portal/portals.conf \ + image/usr/bin/init LINKS = \ image/bin \ diff --git a/img/app/image/etc/init b/img/app/image/usr/bin/init similarity index 100% rename from img/app/image/etc/init rename to img/app/image/usr/bin/init base-commit: 651da813154329e8398a23dbaabdeef633c1f2a6 -- 2.51.0

3 14

[PATCH 0/4] Minor improvements to scripts/run-qemu.sh
by Demi Marie Obenour 14 Nov '25

14 Nov '25

None of these are major changes. See individual commit messages for details. Signed-off-by: Demi Marie Obenour <demiobenour(a)gmail.com> --- Demi Marie Obenour (4): scripts/run-qemu.sh: better error checks & formatting scripts/run-qemu.sh: decrease indentation scripts/run-qemu.sh: Preserve ,, in QEMU arguments scripts/run-qemu.sh: Unset variables from the environment scripts/run-qemu.sh | 123 +++++++++++++++++++++++++++------------------------- 1 file changed, 65 insertions(+), 58 deletions(-) --- base-commit: 22e216712322cdfb85094bbd27ff34c4366fad41 change-id: 20251107-simple-sh-quote-fix-cf956d5422c3 -- Sincerely, Demi Marie Obenour (she/her/hers)

3 15

[PATCH] tools: use llvmPackages as input
by Alyssa Ross 13 Nov '25

13 Nov '25

This makes sure that clang and clang-tidy will be using the same version of LLVM. (It's looking like we might also need LLVM libunwind at some point, so that's another thing we could take from a single llvmPackages.) Signed-off-by: Alyssa Ross <hi(a)alyssa.is> --- tools/default.nix | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/tools/default.nix b/tools/default.nix index 398f570..06b7ed2 100644 --- a/tools/default.nix +++ b/tools/default.nix @@ -5,9 +5,9 @@ import ../lib/call-package.nix ( { src, lib, stdenv, fetchCrate, fetchurl, runCommand, buildPackages , meson, ninja, pkg-config, rustc -, clang-tools, clippy, jq +, llvmPackages, clippy, jq , dbus, linuxHeaders -, clang, libbpf +, libbpf , buildSupport ? false , appSupport ? true , hostSupport ? false @@ -86,7 +86,7 @@ stdenv.mkDerivation (finalAttrs: { nativeBuildInputs = [ meson ninja ] ++ lib.optionals (appSupport || driverSupport) [ pkg-config ] ++ lib.optionals hostSupport [ rustc ] - ++ lib.optionals driverSupport [ clang.cc ]; + ++ lib.optionals driverSupport [ llvmPackages.clang-unwrapped ]; buildInputs = lib.optionals appSupport [ dbus ] ++ lib.optionals driverSupport [ libbpf linuxHeaders ]; @@ -121,7 +121,7 @@ stdenv.mkDerivation (finalAttrs: { # clang-tools needs to be before clang, otherwise it will not use # the Nix include path correctly and fail to find headers - nativeBuildInputs = [ clang-tools jq ] ++ nativeBuildInputs; + nativeBuildInputs = [ llvmPackages.clang-tools jq ] ++ nativeBuildInputs; buildPhase = '' jq -r '.[].file | select(endswith(".c"))' compile_commands.json | base-commit: 1d666582892fbdf812662b4490caf7821078eaf9 -- 2.51.0

2 1

[PATCH] tools/start-vmm: enable Cloud Hypervisor landlock
by Alyssa Ross 13 Nov '25

13 Nov '25

We can't really predict the device paths or IOMMU groups statically, so this is as good as it gets with landlock rules. We'll be able to do other things to further lock things down though, like running different Cloud Hypervisor instances as different users, and changing ownership of each IOMMU group in /dev/vfio/vfio to match. Signed-off-by: Alyssa Ross <hi(a)alyssa.is> --- tools/start-vmm/ch.rs | 8 ++++++++ tools/start-vmm/lib.rs | 15 +++++++++++++-- 2 files changed, 21 insertions(+), 2 deletions(-) diff --git a/tools/start-vmm/ch.rs b/tools/start-vmm/ch.rs index 80e75dc..ed2d457 100644 --- a/tools/start-vmm/ch.rs +++ b/tools/start-vmm/ch.rs @@ -69,6 +69,12 @@ pub struct VsockConfig { pub socket: String, } +#[derive(Serialize)] +pub struct LandlockConfig { + pub path: String, + pub access: &'static str, +} + #[derive(Serialize)] pub struct VmConfig { pub console: ConsoleConfig, @@ -80,6 +86,8 @@ pub struct VmConfig { pub payload: PayloadConfig, pub serial: ConsoleConfig, pub vsock: VsockConfig, + pub landlock_enable: bool, + pub landlock_rules: Vec<LandlockConfig>, } fn command(vm_dir: &Path, s: impl AsRef<OsStr>) -> Command { diff --git a/tools/start-vmm/lib.rs b/tools/start-vmm/lib.rs index 5dc5ae7..9a77780 100644 --- a/tools/start-vmm/lib.rs +++ b/tools/start-vmm/lib.rs @@ -14,8 +14,8 @@ use std::io::{self, ErrorKind}; use std::path::Path; use ch::{ - ConsoleConfig, DiskConfig, FsConfig, GpuConfig, MemoryConfig, PayloadConfig, VmConfig, - VsockConfig, + ConsoleConfig, DiskConfig, FsConfig, GpuConfig, LandlockConfig, MemoryConfig, PayloadConfig, + VmConfig, VsockConfig, }; use net::net_setup; @@ -130,6 +130,17 @@ pub fn vm_config(vm_dir: &Path) -> Result<VmConfig, String> { cid: 3, socket: vm_dir.join("vsock").into_os_string().into_string().unwrap(), }, + landlock_enable: true, + landlock_rules: vec![ + LandlockConfig { + path: "/sys/devices".to_owned(), + access: "rw", + }, + LandlockConfig { + path: "/dev/vfio".to_owned(), + access: "rw", + }, + ], }) } base-commit: 50f8db9cec022a60ea978bfdde0904a18718d161 -- 2.51.0

3 2

config.nix validation?
by Demi Marie Obenour 09 Nov '25

09 Nov '25

Should the values from config.nix be validated in any way? They are obviously trusted, but it is very easy for the users to make mistakes that could cause extremely confusing problems. For instance, the update patch doesn't support URLs with a query string or a fragment specifier. In fact, such URLs could get mangled. There are other URLs that tools like curl will accept but which will break the build. Should these be validated with regular expressions before use? That will result in build-time errors that at least somewhat point to the source of the problem, rather than mysterious build-time or runtime misbehavior. -- Sincerely, Demi Marie Obenour (she/her/hers)

2 3

[PATCH 0/2] release/checks/shfmt: init
by Alyssa Ross 09 Nov '25

09 Nov '25

The default formatting seems unobjectionable to me, but if anybody wants to lobby for different sh formatting rules, now's the time. :) Alyssa Ross (2): scripts: format with shfmt release/checks/shfmt: init release/checks/default.nix | 2 + release/checks/shfmt.nix | 15 +++++ scripts/dist-cloud-hypervisor.sh | 4 +- scripts/format-uuid.sh | 2 +- scripts/make-erofs.sh | 8 +-- scripts/run-qemu.sh | 109 ++++++++++++++++--------------- scripts/update-nixpkgs.sh | 4 +- 7 files changed, 81 insertions(+), 63 deletions(-) create mode 100644 release/checks/shfmt.nix base-commit: e9480cfdf8cba16d0e0b8ee2db3a916979804db9 -- 2.51.0

3 6

[PATCH] img/app: Use set -euo pipefail for building the erofs
by Demi Marie Obenour 09 Nov '25

09 Nov '25

This caught problems when I was trying to filter the set of files to be built. Signed-off-by: Demi Marie Obenour <demiobenour(a)gmail.com> --- img/app/Makefile | 1 + 1 file changed, 1 insertion(+) diff --git a/img/app/Makefile b/img/app/Makefile index 981889ebe55d9ba03228977f3dc0ea3f26d5c4fb..48eba871339d314479f730101246ace3fa39e2db 100644 --- a/img/app/Makefile +++ b/img/app/Makefile @@ -46,6 +46,7 @@ build/empty: mkdir -p $@ build/rootfs.erofs: ../../scripts/make-erofs.sh $(PACKAGES_FILE) $(FILES) $(BUILD_FILES) build/empty build/fifo file-list.mk + set -euo pipefail; \ { \ cat $(PACKAGES_FILE) ;\ for file in $(FILES) $(LINKS); do printf '%s\n%s\n' $$file "$${file#image/}"; done ;\ --- base-commit: 22e216712322cdfb85094bbd27ff34c4366fad41 change-id: 20251107-pipefail-92dd75264707 -- Sincerely, Demi Marie Obenour (she/her/hers)

3 2

[PATCH 0/2] host/rootfs: remove unnecessary coldplug dependencies
by Alyssa Ross 09 Nov '25

09 Nov '25

I didn't want to block the udev series on this, but I really don't think these dependencies are necessary. Rationale in each patch. Alyssa Ross (2): host/rootfs: remove vmm-env coldplug dependency host/rootfs: remove vm-env coldplug dependency host/rootfs/file-list.mk | 2 -- .../image/etc/s6-rc/vm-env/contents.d/systemd-udevd-coldplug | 0 .../image/etc/s6-rc/vmm-env/contents.d/systemd-udevd-coldplug | 0 3 files changed, 2 deletions(-) delete mode 100644 host/rootfs/image/etc/s6-rc/vm-env/contents.d/systemd-udevd-coldplug delete mode 100644 host/rootfs/image/etc/s6-rc/vmm-env/contents.d/systemd-udevd-coldplug base-commit: 36d2f0bd5caf297efec0e41f42e5983ae9dc1cb1 -- 2.51.0

1 2