if stdin is connected to a closed pipe or similar, imply
PTY_FORWARD_READ_ONLY so we don't even try to read from it
in the first place. Otherwise we'll immediately get a hangup
which will cause the forwarder to call sd_event_exit() and
shut down the event loop.
Debugged-by: Christian Brauner <brauner@kernel.org>
# Context
#40195 defines the initial proposal and the motivation behind this PR.
This PR introduces 3 new options for `.link` files `[Link]` section:
- `IRQAffinityPolicy=`
- `IRQAffinity=`
- `IRQAffinityNUMA=`
The purpose is to allow `systemd-udevd` to configure a NIC's IRQs
affinity to specific CPU(s).
`IRQAffinityPolicy=` supports two policies:
- `single`: assign all the NIC IRQs to CPU 0, or the first CPU in the
CPU set resulting from the union of `IRQAffinity=` and
`IRQAffinityNUMA=`.
- `spread`: assign all the NIC IRQs to all the CPUs (or the union of
`IRQAffinity=` and `IRQAffinityNUMA=` if defined) in a round-robin
fashion while optimizing for cache locally while spreading apart queues
on CPUs as much as possible.
Both `IRQAffinity=` and `IRQAffinityNUMA=` behaves as filters to reduce
the CPU set to assign IRQs to, and are only valid if
`IRQAffinityPolicy=` is defined.
# Spreading IRQs
This section describes the algorithm responsible for spreading IRQs over
different CPUs to maximize performance.
## 1. Discover CPU topology
Read from `/sys/devices/system/cpu/cpu*/topology` to identify:
- L3 cache domains (dies)
- Physical cores VS hyperthreads
- NUMA nodes
- Core ordering within each die
```
Example: Dual-socket server with 2 dies per socket, 4 cores per die
┌─────────────────────────────────────────────────────────────────┐
│ NUMA Node 0 │
│ ┌─────────────────────────┐ ┌─────────────────────────┐ │
│ │ Die 0 (L3 Cache) │ │ Die 1 (L3 Cache) │ │
│ │ ┌────┐┌────┐┌────┐┌────│ │ ┌────┐┌────┐┌────┐┌────│ │
│ │ │ C0 ││ C1 ││ C2 ││ C3 │ │ │ C4 ││ C5 ││ C6 ││ C7 │ │
│ │ │0,16││1,17││2,18││3,19│ │ │4,20││5,21││6,22││7,23│ │
│ │ └────┘└────┘└────┘└────│ │ └────┘└────┘└────┘└────│ │
│ └─────────────────────────┘ └─────────────────────────┘ │
└─────────────────────────────────────────────────────────────────┘
┌─────────────────────────────────────────────────────────────────┐
│ NUMA Node 1 │
│ ┌─────────────────────────┐ ┌─────────────────────────┐ │
│ │ Die 2 (L3 Cache) │ │ Die 3 (L3 Cache) │ │
│ │ ┌────┐┌────┐┌────┐┌────│ │ ┌────┐┌────┐┌────┐┌────│ │
│ │ │ C8 ││ C9 ││C10 ││C11 │ │ │C12 ││C13 ││C14 ││C15 │ │
│ │ │8,24││9,25││10,2││11,2│ │ │12,2││13,2││14,3││15,3│ │
│ │ └────┘└────┘└────┘└────│ │ └────┘└────┘└────┘└────│ │
│ └─────────────────────────┘ └─────────────────────────┘ │
└─────────────────────────────────────────────────────────────────┘
(Numbers show CPU IDs: first HT, second HT)
```
## 2. Filter the first hyperthread only
Use only the first hyperthread of each physical core to avoid SMT
contention. Two IRQs on sibling HTs contend for ALU/cache without cache
benefit.
```
Before: CPUs 0-31 (16 cores × 2 HTs)
After: CPUs 0-15 (first HT of each core)
```
## 3. Equidistant permutations
Reorder dies and CPUs so consecutive selections are maximally spread
apart.
```
Original order: [0, 1, 2, 3] (adjacent dies/CPUs)
|
v
Equidistant: [0, 2, 1, 3] (spread apart)
```
This ensures that even if only 2 IRQs are assigned, they land on dies 0
and 2 (not 0 and 1), maximizing physical distance. The permutation is
also applied within each die:
```
Die permutation: Die0 -> Die2 -> Die1 -> Die3
Within each die:
┌───────────────────────────────────────────────┐
│ Die 0: [C0,C1,C2,C3] -> [C0,C2,C1,C3] │
│ Die 1: [C4,C5,C6,C7] -> [C4,C6,C5,C7] │
│ Die 2: [C8,C9,C10,C11] -> [C8,C10,C9,C11] │
│ Die 3: [C12,C13,C14,C15] -> [C12,C14,C13,C15] │
└───────────────────────────────────────────────┘
```
## 4. Round-robin selection across dies
Pick one CPU from each die in rotation, following permuted order.
```
Round 1: Die0->C0 Die2->C8 Die1->C4 Die3->C12
| | | |
v v v v
IRQs: [IRQ0] [IRQ1] [IRQ2] [IRQ3]
Round 2: Die0->C2 Die2->C10 Die1->C6 Die3->C14
| | | |
v v v v
IRQs: [IRQ4] [IRQ5] [IRQ6] [IRQ7]
```
If there are more IRQs than physical cores, this logic wraps around and
reuse CPUs. Only the first hyperthread of each core is used to avoid
cache line contention between queues.
Closes#40195.
- test-random-util is reworked to not use sqrt()
- pretty-print.c inlines ceil() so libm doesn't have
to be linked into libshared
- We add fno-math-errno to allow inlining of more math
functions by not requiring standard math functions to
set errno on invalid input.
Run acquire_root_devno() on the varlink-provided node so symlinks (e.g.
/dev/disk/by-id/...) resolve to their canonical /dev/ path before being
used. Without this, sym_fdisk_partname() produces a "-partN" symlink
that udev hasn't created yet when repart calls open() on it right after
BLKPG_ADD_PARTITION, failing with ENOENT.
This also brings the varlink path in line with the CLI path's
partition-to-whole-disk and dm-crypt-to-backing resolution.
This commit move the erros in StartTransient from
VARLINK_ERROR_UNIT_BAD_SETTING to SD_VARLINK_ERROR_INVALID_PARAMETER
and it also ensures we have the bad field in the error.
Thanks to Ivan Kruglov for suggesting this.
This commit adds more writable fields to the io.systemd.Unit.StartTransient
varlink method. With this its possible to set:
User,Group,SupplementaryGroups,Nice values.
Plus tests for them.
SNP requires a named, stable CPU model so the launch measurement is
reproducible across hosts. EPYC-v4 is the baseline that covers all
SNP-capable processors (Milan and later).
Signed-off-by: Paul Meyer <katexochen0@gmail.com>
Add --confidential-computing=sev-snp to run the guest as an AMD SEV-SNP
confidential VM. Loads a raw OVMF firmware blob via -bios (SNP doesn't
support the pflash + NVRAM split), attaches a sev-snp-guest object,
and hashes the kernel, initrd and cmdline into the launch measurement
when direct kernel boot is used. Incompatible features (Secure Boot,
CXL, virtio-balloon, SMBIOS credentials) are rejected or disabled; an
attached vTPM must be treated as untrusted by the guest.
The feature is marked experimental in the man page.
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: Paul Meyer <katexochen0@gmail.com>
Add support for filtering IRQ affinity to CPUs on a specific NUMA node
via the new IRQAffinityNUMA= option in .link files. The option accepts:
- "local": use the NUMA node local to the NIC's PCIe slot
- Explicit node number (0, 1, 2, ...): use CPUs on the specified node
When both IRQAffinity= and IRQAffinityNUMA= are specified, their
intersection is used. If the intersection is empty, an error is logged
and IRQ affinity configuration is skipped.
When "local" is specified but the device's NUMA node cannot be
determined (numa_node shows -1), a warning is logged and IRQ affinity
configuration is skipped.
Add IRQAffinity= option to .link files that filters the set of CPUs
eligible for IRQ placement. This works in conjunction with
IRQAffinityPolicy= to constrain which CPUs receive network IRQs.
When specified with spread policy, only the listed CPUs are considered
for IRQ distribution. When specified with single policy, IRQs are
pinned to the first CPU in the allowed set instead of CPU 0.
Implement the spread policy for IRQ affinity distribution using a
topology-aware algorithm. The algorithm:
1. Discovers CPU topology from sysfs (NUMA node, package, die/L3, core)
2. Groups CPUs by L3 cache domain (die) with equidistant ordering
3. Round-robins across dies, spreading IRQs across the system
4. Uses first hyperthread of each core before second hyperthreads
5. Applies IRQ affinity via /proc/irq/<n>/smp_affinity
When there are more IRQs than CPUs, queues wrap around using round-robin.
Add support for configuring IRQ affinity for network interfaces via
systemd .link files. For now, the new IRQAffinityPolicy= option in the [Link]
section only accepts "single", which pins all MSI IRQs to CPU 0.
This allows declarative IRQ affinity configuration for network devices
during udev processing, which is useful for optimizing network
performance on multi-core systems.
Further commits will expand the options supported by IRQAffinityPolicy=.
Just like for the unsupported/bad exec_fields we should show
a message about what field is bad for service parameters. This
commit adds it using the same pattern. The JSON parser works in
fail-fast mode so we only display the first bad field (and
it depends on the parser what it finds first).
Let's bail out early if the packet claims to contain some
questions or answer RRs, but the remaining packet data size is not
enough to hold a single such entry.
Follow-up for e7cd836dcf.
exp10() has a symbol version > 2.34 on latest glibc. To allow
dropping our baseline required glibc runtime version to <= 2.34,
let's add our own version to prevent pulling in the newer symbol
from glibc.
Methods:
- `io.systemd.Job.List` — list all queued jobs or look up by `id`/`unit`
name, with streaming support. Uses context/runtime split: `JobContext`
(Unit, JobType) and `JobRuntime` (Id, State, Result,
ActivationDetails). Follows the same SELinux and parameter-conflict
patterns as `io.systemd.Unit.List`.
- `io.systemd.Job.Cancel` — cancel a specific job by ID, with SELinux
and polkit authorization.
- `io.systemd.Job.ClearAll` — cancel all pending jobs, with SELinux and
polkit authorization.
There exists a small window of time in icmp6_bind() between creating the
ICMPv6 socket and binding it to an ifindex, where the link-scoped socket
can process an ICMPv6 packet received on any interface. The applies to
both sd-radv and sd-ndisc codepaths.
This change adds an explicit check for ifindex on the receive path and
ignores packets received on other interfaces.
Co-developed-by: OpenAI Codex <noreply@openai.com>
`message_skip_fields()` recursively processes D-Bus variant types in
message header fields with no depth limit. A crafted message with deeply
nested variants can cause unbounded recursion and overflow the stack.
Add a `depth` parameter checked against `BUS_CONTAINER_DEPTH` (128),
matching the limit already enforced by the public
`sd_bus_message_skip()` API. All recursive call sites pass `depth + 1`,
and the top-level caller in `message_parse_fields()` passes `0`.
The existing error reporting for the varlink `StartTransient` code
was converting all errors into `VARLINK_ERROR_UNIT_BAD_SETTING`.
This is not correct in some cases, we need to have a more targted
pattern here, i.e. only convert EINVAL to VARLINK_ERROR_UNIT_BAD_SETTING
and otherwise return the matching varlink error from the errno instead.
This commit fixes this issue. Thanks to Ivan Kruglov for raising
this.
Each dlopen_*() wrapper kept its dl handle as a file-scope
'static void *xxx_dl = NULL;' even though only the wrapper itself
ever referenced it. Move each one inside the corresponding function
so its scope matches its actual use, leaving the rest of each
translation unit free of the unused file-scope name.
In pcre2-util.c the assert(pcre2_dl) in pattern_matches_and_log()
becomes assert(sym_pcre2_match), which carries the same invariant
(pattern_compile_and_log() ran dlopen_pcre2()).
Craft a raw D-Bus message with an unknown header field containing
BUS_CONTAINER_DEPTH+1 nested variants and verify that message parsing
rejects it with -EBADMSG rather than recursing until stack overflow.
message_skip_fields() recurses for each nested variant ('v') type in
D-Bus message header fields. A crafted message with deeply nested
variants (e.g., a variant containing a variant containing a variant...)
causes unbounded stack growth, leading to stack overflow and crash.
Add a depth parameter that increments on each recursive call and
rejects messages exceeding BUS_CONTAINER_DEPTH with -EBADMSG. This
matches the existing depth limits enforced elsewhere in the sd-bus
message processing (e.g., bus_message_enter_container).
as specified by the haproxy documentation:
https://www.haproxy.org/download/1.8/doc/proxy-protocol.txt
only protocol v1 is implemented for now, protocol v2 is binary,
and will be implemented in the future.
the proxy protocol allows the destination/target to know the
address/port of the client connectiing.
in nginx it's supported by enabling the `proxy_protocol` parameter to
the `listen` directive.
Each dlopen_*() wrapper kept its dl handle as a file-scope
'static void *xxx_dl = NULL;' even though only the wrapper itself
ever referenced it. Move each one inside the corresponding function
so its scope matches its actual use, leaving the rest of each
translation unit free of the unused file-scope name.
In pcre2-util.c the assert(pcre2_dl) in pattern_matches_and_log()
becomes assert(sym_pcre2_match), which carries the same invariant
(pattern_compile_and_log() ran dlopen_pcre2()).
Some drivers (currently mlx5_core) expose sub-functions (SFs) of a PCI
Physical or Virtual Function as auxiliary devices that carry a stable
`sfnum` sysfs attribute (the user-defined SF number passed to `devlink
port add ... sfnum N`). Their leaf devices (net, infiniband, ...)
currently inherit the parent PF/VF's `ID_PATH` and the SF netdev falls
through to the kernel-assigned `eth<N>` name.
Two patches:
1. `udev-builtin-path_id`: prepend an `sf-<N>` token when the walk
crosses an aux device with `sfnum`, so SF leaf devices get an `ID_PATH`
distinct from the parent PF/VF (e.g. `pci-0000:c1:00.0-sf-88`). Aux
devices without `sfnum` keep the pre-patch behaviour, so existing
`ID_PATH` values are unchanged and the patch needs no naming-scheme gate
(path_id is unversioned).
2. `udev-builtin-net_id`: name SF host netdevs analogously to SR-IOV VF
host netdevs — walk to the parent PCI function and append a
single-character `S<sfnum>` suffix. SFs hosted on SR-IOV VFs (VF-SF) get
both suffixes chained on the PF's base name (`enp193s0f0v0S88`). Gated
behind `NAMING_SUBFUNC` / `NAMING_V261`. Man page
(`systemd.net-naming-scheme(7)`) updated.
The patches apply to any driver that exposes its SF leaf devices below
an aux device exposing `sfnum`.
Validated on mlx5 hardware: PF, VF, SF-on-PF (`enp8s0f0S88`,
`pci-0000:08:00.0-sf-88`). VF-SF case verified with a fake-sysfs setup
since this is not supported by any real device and is more a theoretical
use case.
Since [0] and [1] questions & answer RRs from the incoming packets are
parsed into a hashmap to speed things up. The hashmaps are even
pre-allocated to speed things up even more, but there's one caveat - the
size for the pre-allocation comes from one or more fields from the
incoming packets that are under sender's control.
This can be abused by a malicious DNS server which can send a packet
with a spoofed QDCOUNT (for question packets) or ANCOUNT/NSCOUNT/ARCOUNT
(for answer packets). The limit of the final value in both cases is 64K.
This value is then used to pre-allocate the hashmap (via
set_reserve()/ordered_set_reserve(), where the caller also multiplies
the input value by 2 in both cases), which in turns calls
resize_buckets() that memzero()s the pre-allocated area, so all the
pages are faulted in, showing in process' RSS. Each such spoofed packet
then can translate into a ~4 MiB allocation in the systemd-resolved
process, which doesn't sound that bad.
However, this can be further amplified if the spoofed packet ends up in
resolved's cache. So, if the spoofed packet contains one valid A record
and then an OPT record with a spoofed ARCOUNT, the whole packet ends up
in the cache that can hold 4K of entries, which can eventually cause
resolved to keep up to 16 GiB of memory just for the cache (and thanks
to the memzero() above it's all RSS). Note that all this requires
someone with enough privileges to configure resolved to actually point
to such malicious DNS server or it could come from a malicious DHCP
server on the network. This could also get exploited via LLMNR, but in
thas case an attacker would have to match an ID of a valid transaction
for the packet to end up in resolved's cache.
For example, with a malicious DNS already in resolved configuration:
$ resolvectl dns eth0
Link 2 (eth0): 192.168.99.1:5354
Filling resolved's cache:
$ for i in {0..4200}; do resolvectl query test-$i.example.com; done
...
test-4200.example.com: 192.0.2.1 -- link: dummy0
-- Information acquired via protocol DNS in 1.6ms.
-- Data is authenticated: no; Data was acquired via local or encrypted transport: no
-- Data from: network
Yields following memory increase:
$ while :; do grep VmRSS /proc/$(pidof systemd-resolved)/status; sleep 1; done
VmRSS: 14280 kB
VmRSS: 14280 kB
...
VmRSS: 403352 kB
VmRSS: 1017976 kB
VmRSS: 1603876 kB
VmRSS: 2202028 kB
...
VmRSS: 16795724 kB
VmRSS: 16795724 kB
In my testing I also noticed one annoyance - after certain threshold the
RSS increase persisted even after the malicious entries were evicted
from the cache (or flushed via `resolvectl flush-caches`). This was most
likely due to mmap_threshold getting bumped to > 4 MiB and neither cache
eviction nor flush-caches call malloc_trim(0) (via
sd_event_trim_memory() or similar).
To mitigate this, let's cap the pre-allocation to a maximum number of
records the given packet body can realistically contain. If the minimum
size would be, for whatever unlikely reason, not enough, nothing serious
would happen - the hashmap would still get resized automatically by
resize_buckets(), it'd be just slightly slower.
[0] ae45e1a383
[1] 2d34cf0c16
Add COREDUMP_CODE to the fields captured by systemd-coredump. This makes
it possible for system administrators to filter coredumps based on si_code,
which describes the reason why a given signal was sent.
For example, to find processes killed due to invalid permissions
(SEGV_ACCERR):
$ journalctl COREDUMP_SIGNAL=11 COREDUMP_CODE=2
I've decided to add the value of si_code to the 'Signal: ' line of
coredumpctl info:
Signal: 11 (SEGV) si_code: SEGV_ACCERR
Allow users to allow DHCPv6 unreachable/blackhole routes (installed
for delegated prefixes) into a specific routing table, analogous to
the existing RouteTable= in [DHCPv4] and [IPv6AcceptRA].
The config parser config_parse_dhcp_or_ra_route_table() is extended
with an AF_UNSPEC ltype discriminator for DHCPv6 (AF_INET6 is already
taken by NDISC/RA). link_get_dhcp6_route_table() follows the same
pattern as link_get_dhcp4_route_table() and link_get_ndisc_route_table(),
falling back to the VRF table when not explicitly set.
In dhcp_request_unreachable_route(), the table is applied only for
NETWORK_CONFIG_SOURCE_DHCP6 routes (the uplink unreachable aggregates),
not DHCP_PD routes (per-subnet routes on downstream interfaces), matching
the intent of the feature. The !route->table_set guard avoids overriding
a table already set by the route code.
The current key sealing format has some less-than-ideal weaknesses:
- PBKDF2 with only 65k iterations, where recommendations are ~200k
- AES with null IV, relying on salt for uniqueness
- lack of AES MAC/AEAD
However improbable, it is at least theorically possible that with
a lot of resources an offline bruteforce could be attempted.
Add a v2 sealing format, keeping unsealing compatibility with
the current format:
`v2:<iterations>:<salt>:<IV>:<ciphertext>:<aes tag>`
and use 600k iterations for the PBKDF2 sha512
Some drivers (currently mlx5_core) expose sub-functions (SFs) of a PCI
Physical Function as auxiliary devices. Each SF carries a host network
interface that sits below the aux device in sysfs:
/sys/devices/.../<PF BDF>/mlx5_core.sf.<idx>/net/eth<N>
Because the network device's immediate parent is the aux device and not
a PCI device, names_pci() bails out and these interfaces fall through
to the kernel-assigned eth<N> name, which is not stable across reboots,
module reloads or topology changes.
The naming applies when the SF network device's direct sysfs parent is
the aux device that exposes sfnum, i.e. the kernel driver passes the
aux device to SET_NETDEV_DEV(). mlx5_core does so. ice's
ice_sf_cfg_netdev() currently passes the parent PF's PCI device, so ice
SF network devices sit as siblings of the PF rather than below the aux
device and fall outside this precondition; pending a kernel change in
ice to mirror mlx5's SET_NETDEV_DEV(netdev, &adev->dev), they continue
to receive the kernel-assigned name as they do today.
The aux device exposes 'sfnum', the user-defined sub-function number
(the value passed to "devlink port add ... sfnum N"), which is stable
and unique within its parent PF. The aux device's direct sysfs parent
is the PF's PCI device.
Treat an SF host network device analogously to an SR-IOV VF host
network device: walk to the parent PCI function, derive the base name
from there, then append a single-character "S<sfnum>" suffix. Lowercase
's' is already taken (slot) and the existing grammar uses one character
per token, so 'S' is the best option.
E.g. for an SF whose parent PF is at PCI 0000:c1:00.0 and which was
added with "sfnum 88":
ID_NET_NAME_PATH=enp193s0f0S88
ID_NET_NAME_SLOT=enp193s0f0S88
This is parallel to how SR-IOV VFs get a "v<N>" suffix on top of the
parent PF's name.
Gate the new behaviour behind NAMING_SUBFUNC and NAMING_V261. Document
the new suffix in both the ID_NET_NAME_SLOT and ID_NET_NAME_PATH
grammars in systemd.net-naming-scheme(7) and add a v261 history entry.
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
Some drivers expose sub-functions (SFs) of a PCI Physical or Virtual
Function as auxiliary devices that carry a stable 'sfnum' sysfs
attribute — the user-defined sub-function number (e.g. the value
passed to "devlink port add ... sfnum N"). The SF's leaf devices
(uverbs, infiniband, net, ...) sit below this aux device in sysfs:
/sys/devices/.../<PF or VF BDF>/<sf aux>/.../<leaf>
Currently path_id walks straight past the aux device, so all leaf
devices below an SF end up sharing ID_PATH=pci-<BDF> with their
parent PF or VF. For uverbs this causes a /dev/infiniband/by-path/
symlink collision, and for any other consumer of ID_PATH/ID_PATH_TAG
it makes PF and SF (or VF and VF-SF) indistinguishable.
Recognise the 'auxiliary' subsystem in path_id's walk: when the aux
device exposes 'sfnum', prepend an 'sf-<N>' token; otherwise leave
it untokenised. The result for an SF whose parent PF is at PCI
0000:c1:00.0 and which was added with "sfnum 88" is:
ID_PATH=pci-0000:c1:00.0-sf-88
ID_PATH_TAG=pci-0000_c1_00_0-sf-88
This is parallel to how net_id's NAMING_SUBFUNC scheme appends 'S<N>'
on top of the PF base name. Aux devices without 'sfnum' keep the
pre-patch behaviour: the walk skips over them with no token. Existing
ID_PATH values for PF and VF leaf devices are therefore unchanged,
the change is purely additive, and there is no need to gate it behind
a naming scheme (path_id itself is unversioned).
Co-developed-by: Claude Opus 4.7 <noreply@anthropic.com>
The current key sealing format has some less-than-ideal weaknesses:
- PBKDF2 with only 65k iterations, where recommendations are ~200k
- AES with null IV, relying on salt for uniqueness
- lack of AES MAC/AEAD
However improbable, it is at least theorically possible that with
a lot of resources an offline bruteforce could be attempted.
Add a v2 sealing format, keeping unsealing compatibility with
the current format:
v2:<iterations>:<salt>:<IV>:<ciphertext>:<aes tag>
and use 600k iterations for the PBKDF2 sha512
Filesystems like xfs, btrfs, gfs2 and ocfs2 handle quotas internally
and do not need external quotacheck/quotaon services. When usrquota or
grpquota mount options are used in fstab for these filesystems,
generator_hook_up_quotacheck() falls through to the !fstype_needs_quota()
branch and emits a misleading warning that quotas are "not supported"
when they actually work fine — the kernel handles them internally.
Add fstype_has_internal_quota() to return early with a debug message,
and adopt a tri-state return convention so the caller skips quotaon
when quotacheck was not needed.
The buggy code path was introduced in #24824 and #24880.
Co-developed-by: Claude Opus 4.6 <noreply@anthropic.com>