The most significant set of changes is the per netns RTNL. The new
behavior is disabled by default, regression risk should be contained.
Notably the new config knob PTP_1588_CLOCK_VMCLOCK will inherit its
default value from PTP_1588_CLOCK_KVM, as the first is intended to be
a more reliable replacement for the latter.
Core
----
- Started a very large, in-progress, effort to make the RTNL lock
scope per network-namespace, thus reducing the lock contention
significantly in the containerized use-case, comprising:
- RCU-ified some relevant slices of the FIB control path
- introduce basic per netns locking helpers
- namespacified the IPv4 address hash table
- remove rtnl_register{,_module}() in favour of rtnl_register_many()
- refactor rtnl_{new,del,set}link() moving as much validation as
possible out of RTNL lock
- convert all phonet doit() and dumpit() handlers to RCU
- convert IPv4 addresses manipulation to per-netns RTNL
- convert virtual interface creation to per-netns RTNL
the per-netns lock infra is guarded by the CONFIG_DEBUG_NET_SMALL_RTNL
knob, disabled by default ad interim.
- Introduce NAPI suspension, to efficiently switching between busy
polling (NAPI processing suspended) and normal processing.
- Migrate the IPv4 routing input, output and control path from direct
ToS usage to DSCP macros. This is a work in progress to make ECN
handling consistent and reliable.
- Add drop reasons support to the IPv4 rotue input path, allowing
better introspection in case of packets drop.
- Make FIB seqnum lockless, dropping RTNL protection for read
access.
- Make inet{,v6} addresses hashing less predicable.
- Allow providing timestamp OPT_ID via cmsg, to correlate TX packets
and timestamps
Things we sprinkled into general kernel code
--------------------------------------------
- Add small file operations for debugfs, to reduce the struct ops size.
- Refactoring and optimization for the implementation of page_frag API,
This is a preparatory work to consolidate the page_frag
implementation.
Netfilter
---------
- Optimize set element transactions to reduce memory consumption
- Extended netlink error reporting for attribute parser failure.
- Make legacy xtables configs user selectable, giving users
the option to configure iptables without enabling any other config.
- Address a lot of false-positive RCU issues, pointed by recent
CI improvements.
BPF
---
- Put xsk sockets on a struct diet and add various cleanups. Overall,
this helps to bump performance by 12% for some workloads.
- Extend BPF selftests to increase coverage of XDP features in
combination with BPF cpumap.
- Optimize and homogenize bpf_csum_diff helper for all archs and also
add a batch of new BPF selftests for it.
- Extend netkit with an option to delegate skb->{mark,priority}
scrubbing to its BPF program.
- Make the bpf_get_netns_cookie() helper available also to tc(x) BPF
programs.
Protocols
---------
- Introduces 4-tuple hash for connected udp sockets, speeding-up
significantly connected sockets lookup.
- Add a fastpath for some TCP timers that usually expires after close,
the socket lock contention.
- Add inbound and outbound xfrm state caches to speed up state lookups.
- Avoid sending MPTCP advertisements on stale subflows, reducing
risks on loosing them.
- Make neighbours table flushing more scalable, maintaining per device
neigh lists.
Driver API
----------
- Introduce a unified interface to configure transmission H/W shaping,
and expose it to user-space via generic-netlink.
- Add support for per-NAPI config via netlink. This makes napi
configuration persistent across queues removal and re-creation.
Requires driver updates, currently supported drivers are:
nVidia/Mellanox mlx4 and mlx5, Broadcom brcm and Intel ice.
- Add ethtool support for writing SFP / PHY firmware blocks.
- Track RSS context allocation from ethtool core.
- Implement support for mirroring to DSA CPU port, via TC mirror
offload.
- Consolidate FDB updates notification, to avoid duplicates on
device-specific entries.
- Expose DPLL clock quality level to the user-space.
- Support master-slave PHY config via device tree.
Tests and tooling
-----------------
- forwarding: introduce deferred commands, to simplify
the cleanup phase
Drivers
-------
- Updated several drivers - Amazon vNic, Google vNic, Microsoft vNic,
Intel e1000e and Broadcom Tigon3 - to use netdev-genl to link the
IRQs and queues to NAPI IDs, allowing busy polling and better
introspection.
- Ethernet high-speed NICs:
- nVidia/Mellanox:
- mlx5:
- a large refactor to implement support for cross E-Switch
scheduling
- refactor H/W conter management to let it scale better
- H/W GRO cleanups
- Intel (100G, ice)::
- adds support for ethtool reset
- implement support for per TX queue H/W shaping
- AMD/Solarflare:
- implement per device queue stats support
- Broadcom (bnxt):
- improve wildcard l4proto on IPv4/IPv6 ntuple rules
- Marvell Octeon:
- Adds representor support for each Resource Virtualization Unit
(RVU) device.
- Hisilicon:
- adds support for the BMC Gigabit Ethernet
- IBM (EMAC):
- driver cleanup and modernization
- Cisco (VIC):
- raise the queues number limit to 256
- Ethernet virtual:
- Google vNIC:
- implements page pool support
- macsec:
- inherit lower device's features and TSO limits when offloading
- virtio_net:
- enable premapped mode by default
- support for XDP socket(AF_XDP) zerocopy TX
- wireguard:
- set the TSO max size to be GSO_MAX_SIZE, to aggregate larger
packets.
- Ethernet NICs embedded and virtual:
- Broadcom ASP:
- enable software timestamping
- Freescale:
- add enetc4 PF driver
- MediaTek: Airoha SoC:
- implement BQL support
- RealTek r8169:
- enable TSO by default on r8168/r8125
- implement extended ethtool stats
- Renesas AVB:
- enable TX checksum offload
- Synopsys (stmmac):
- support header splitting for vlan tagged packets
- move common code for DWMAC4 and DWXGMAC into a separate FPE
module.
- Add the dwmac driver support for T-HEAD TH1520 SoC
- Synopsys (xpcs):
- driver refactor and cleanup
- TI:
- icssg_prueth: add VLAN offload support
- Xilinx emaclite:
- adds clock support
- Ethernet switches:
- Microchip:
- implement support for the lan969x Ethernet switch family
- add LAN9646 switch support to KSZ DSA driver
- Ethernet PHYs:
- Marvel: 88q2x: enable auto negotiation
- Microchip: add support for LAN865X Rev B1 and LAN867X Rev C1/C2
- PTP:
- Add support for the Amazon virtual clock device
- Add PtP driver for s390 clocks
- WiFi:
- mac80211
- EHT 1024 aggregation size for transmissions
- new operation to indicate that a new interface is to be added
- support radio separation of multi-band devices
- move wireless extension spy implementation to libiw
- Broadcom:
- brcmfmac: optional LPO clock support
- Microchip:
- add support for Atmel WILC3000
- Qualcomm (ath12k):
- firmware coredump collection support
- add debugfs support for a multitude of statistics
- Qualcomm (ath5k):
- Arcadyan ARV45XX AR2417 & Gigaset SX76[23] AR241[34]A support
- Realtek:
- rtw88: 8821au and 8812au USB adapters support
- rtw89: add thermal protection
- rtw89: fine tune BT-coexsitence to improve user experience
- rtw89: firmware secure boot for WiFi 6 chip
- Bluetooth
- add Qualcomm WCN785x support for ids Foxconn 0xe0fc/0xe0f3 and
0x13d3:0x3623
- add Realtek RTL8852BE support for id Foxconn 0xe123
- add MediaTek MT7920 support for wireless module ids
- btintel_pcie: add handshake between driver and firmware
- btintel_pcie: add recovery mechanism
- btnxpuart: add GPIO support to power save feature
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Paolo Abeni:
"The most significant set of changes is the per netns RTNL. The new
behavior is disabled by default, regression risk should be contained.
Notably the new config knob PTP_1588_CLOCK_VMCLOCK will inherit its
default value from PTP_1588_CLOCK_KVM, as the first is intended to be
a more reliable replacement for the latter.
Core:
- Started a very large, in-progress, effort to make the RTNL lock
scope per network-namespace, thus reducing the lock contention
significantly in the containerized use-case, comprising:
- RCU-ified some relevant slices of the FIB control path
- introduce basic per netns locking helpers
- namespacified the IPv4 address hash table
- remove rtnl_register{,_module}() in favour of
rtnl_register_many()
- refactor rtnl_{new,del,set}link() moving as much validation as
possible out of RTNL lock
- convert all phonet doit() and dumpit() handlers to RCU
- convert IPv4 addresses manipulation to per-netns RTNL
- convert virtual interface creation to per-netns RTNL
the per-netns lock infrastructure is guarded by the
CONFIG_DEBUG_NET_SMALL_RTNL knob, disabled by default ad interim.
- Introduce NAPI suspension, to efficiently switching between busy
polling (NAPI processing suspended) and normal processing.
- Migrate the IPv4 routing input, output and control path from direct
ToS usage to DSCP macros. This is a work in progress to make ECN
handling consistent and reliable.
- Add drop reasons support to the IPv4 rotue input path, allowing
better introspection in case of packets drop.
- Make FIB seqnum lockless, dropping RTNL protection for read access.
- Make inet{,v6} addresses hashing less predicable.
- Allow providing timestamp OPT_ID via cmsg, to correlate TX packets
and timestamps
Things we sprinkled into general kernel code:
- Add small file operations for debugfs, to reduce the struct ops
size.
- Refactoring and optimization for the implementation of page_frag
API, This is a preparatory work to consolidate the page_frag
implementation.
Netfilter:
- Optimize set element transactions to reduce memory consumption
- Extended netlink error reporting for attribute parser failure.
- Make legacy xtables configs user selectable, giving users the
option to configure iptables without enabling any other config.
- Address a lot of false-positive RCU issues, pointed by recent CI
improvements.
BPF:
- Put xsk sockets on a struct diet and add various cleanups. Overall,
this helps to bump performance by 12% for some workloads.
- Extend BPF selftests to increase coverage of XDP features in
combination with BPF cpumap.
- Optimize and homogenize bpf_csum_diff helper for all archs and also
add a batch of new BPF selftests for it.
- Extend netkit with an option to delegate skb->{mark,priority}
scrubbing to its BPF program.
- Make the bpf_get_netns_cookie() helper available also to tc(x) BPF
programs.
Protocols:
- Introduces 4-tuple hash for connected udp sockets, speeding-up
significantly connected sockets lookup.
- Add a fastpath for some TCP timers that usually expires after
close, the socket lock contention.
- Add inbound and outbound xfrm state caches to speed up state
lookups.
- Avoid sending MPTCP advertisements on stale subflows, reducing
risks on loosing them.
- Make neighbours table flushing more scalable, maintaining per
device neigh lists.
Driver API:
- Introduce a unified interface to configure transmission H/W
shaping, and expose it to user-space via generic-netlink.
- Add support for per-NAPI config via netlink. This makes napi
configuration persistent across queues removal and re-creation.
Requires driver updates, currently supported drivers are:
nVidia/Mellanox mlx4 and mlx5, Broadcom brcm and Intel ice.
- Add ethtool support for writing SFP / PHY firmware blocks.
- Track RSS context allocation from ethtool core.
- Implement support for mirroring to DSA CPU port, via TC mirror
offload.
- Consolidate FDB updates notification, to avoid duplicates on
device-specific entries.
- Expose DPLL clock quality level to the user-space.
- Support master-slave PHY config via device tree.
Tests and tooling:
- forwarding: introduce deferred commands, to simplify the cleanup
phase
Drivers:
- Updated several drivers - Amazon vNic, Google vNic, Microsoft vNic,
Intel e1000e and Broadcom Tigon3 - to use netdev-genl to link the
IRQs and queues to NAPI IDs, allowing busy polling and better
introspection.
- Ethernet high-speed NICs:
- nVidia/Mellanox:
- mlx5:
- a large refactor to implement support for cross E-Switch
scheduling
- refactor H/W conter management to let it scale better
- H/W GRO cleanups
- Intel (100G, ice)::
- add support for ethtool reset
- implement support for per TX queue H/W shaping
- AMD/Solarflare:
- implement per device queue stats support
- Broadcom (bnxt):
- improve wildcard l4proto on IPv4/IPv6 ntuple rules
- Marvell Octeon:
- Add representor support for each Resource Virtualization Unit
(RVU) device.
- Hisilicon:
- add support for the BMC Gigabit Ethernet
- IBM (EMAC):
- driver cleanup and modernization
- Cisco (VIC):
- raise the queues number limit to 256
- Ethernet virtual:
- Google vNIC:
- implement page pool support
- macsec:
- inherit lower device's features and TSO limits when
offloading
- virtio_net:
- enable premapped mode by default
- support for XDP socket(AF_XDP) zerocopy TX
- wireguard:
- set the TSO max size to be GSO_MAX_SIZE, to aggregate larger
packets.
- Ethernet NICs embedded and virtual:
- Broadcom ASP:
- enable software timestamping
- Freescale:
- add enetc4 PF driver
- MediaTek: Airoha SoC:
- implement BQL support
- RealTek r8169:
- enable TSO by default on r8168/r8125
- implement extended ethtool stats
- Renesas AVB:
- enable TX checksum offload
- Synopsys (stmmac):
- support header splitting for vlan tagged packets
- move common code for DWMAC4 and DWXGMAC into a separate FPE
module.
- add dwmac driver support for T-HEAD TH1520 SoC
- Synopsys (xpcs):
- driver refactor and cleanup
- TI:
- icssg_prueth: add VLAN offload support
- Xilinx emaclite:
- add clock support
- Ethernet switches:
- Microchip:
- implement support for the lan969x Ethernet switch family
- add LAN9646 switch support to KSZ DSA driver
- Ethernet PHYs:
- Marvel: 88q2x: enable auto negotiation
- Microchip: add support for LAN865X Rev B1 and LAN867X Rev C1/C2
- PTP:
- Add support for the Amazon virtual clock device
- Add PtP driver for s390 clocks
- WiFi:
- mac80211
- EHT 1024 aggregation size for transmissions
- new operation to indicate that a new interface is to be added
- support radio separation of multi-band devices
- move wireless extension spy implementation to libiw
- Broadcom:
- brcmfmac: optional LPO clock support
- Microchip:
- add support for Atmel WILC3000
- Qualcomm (ath12k):
- firmware coredump collection support
- add debugfs support for a multitude of statistics
- Qualcomm (ath5k):
- Arcadyan ARV45XX AR2417 & Gigaset SX76[23] AR241[34]A support
- Realtek:
- rtw88: 8821au and 8812au USB adapters support
- rtw89: add thermal protection
- rtw89: fine tune BT-coexsitence to improve user experience
- rtw89: firmware secure boot for WiFi 6 chip
- Bluetooth
- add Qualcomm WCN785x support for ids Foxconn 0xe0fc/0xe0f3 and
0x13d3:0x3623
- add Realtek RTL8852BE support for id Foxconn 0xe123
- add MediaTek MT7920 support for wireless module ids
- btintel_pcie: add handshake between driver and firmware
- btintel_pcie: add recovery mechanism
- btnxpuart: add GPIO support to power save feature"
* tag 'net-next-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1475 commits)
mm: page_frag: fix a compile error when kernel is not compiled
Documentation: tipc: fix formatting issue in tipc.rst
selftests: nic_performance: Add selftest for performance of NIC driver
selftests: nic_link_layer: Add selftest case for speed and duplex states
selftests: nic_link_layer: Add link layer selftest for NIC driver
bnxt_en: Add FW trace coredump segments to the coredump
bnxt_en: Add a new ethtool -W dump flag
bnxt_en: Add 2 parameters to bnxt_fill_coredump_seg_hdr()
bnxt_en: Add functions to copy host context memory
bnxt_en: Do not free FW log context memory
bnxt_en: Manage the FW trace context memory
bnxt_en: Allocate backing store memory for FW trace logs
bnxt_en: Add a 'force' parameter to bnxt_free_ctx_mem()
bnxt_en: Refactor bnxt_free_ctx_mem()
bnxt_en: Add mem_valid bit to struct bnxt_ctx_mem_type
bnxt_en: Update firmware interface spec to 1.10.3.85
selftests/bpf: Add some tests with sockmap SK_PASS
bpf: fix recursive lock when verdict program return SK_PASS
wireguard: device: support big tcp GSO
wireguard: selftests: load nf_conntrack if not present
...
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Merge tag 'vfs-6.13.rust.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs rust file abstractions from Christian Brauner:
"This contains the file abstractions needed by the Rust implementation
of the Binder driver and other parts of the kernel.
Let's treat this as a first attempt at getting something working but I
do expect the actual interfaces to change significantly over time.
Simply because we are still figuring out what actually works. But
there's no point in further theorizing. Let's see how it holds up with
actual users"
* tag 'vfs-6.13.rust.file' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
rust: task: adjust safety comments in Task methods
rust: add seqfile abstraction
rust: file: add abstraction for `poll_table`
rust: file: add `Kuid` wrapper
rust: file: add `FileDescriptorReservation`
rust: security: add abstraction for secctx
rust: cred: add Rust abstraction for `struct cred`
rust: file: add Rust abstraction for `struct file`
rust: task: add `Task::current_raw`
rust: types: add `NotThreadSafe`
Cross-merge networking fixes after downstream PR (net-6.12-rc4).
Conflicts:
107a034d5c ("net/mlx5: qos: Store rate groups in a qos domain")
1da9cfd6c4 ("net/mlx5: Unregister notifier on eswitch init failure")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The `Task` struct has several safety comments that aren't so great. For
example, the reason that it's okay to read the `pid` is that the field
is immutable, so there is no data race, which is not what the safety
comment says.
Thus, improve the safety comments. Also add an `as_ptr` helper. This
makes it easier to read the various accessors on Task, as `self.0` may
be confusing syntax for new Rust users.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241015-task-safety-cmnts-v1-1-46ee92c82768@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Here is a single driver core fix, and a .mailmap update, for 6.12-rc3.
The fix is for the rust driver core bindings, turned out that the
from_raw binding wasn't a good idea (don't want to pass a pointer to a
reference counted object without actually incrementing the pointer.) So
this change fixes it up as the from_raw binding came in in -rc1.
The other change is a .mailmap update.
Both have been in linux-next for a while with no reported issues.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'driver-core-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here is a single driver core fix, and a .mailmap update.
The fix is for the rust driver core bindings, turned out that the
from_raw binding wasn't a good idea (don't want to pass a pointer to a
reference counted object without actually incrementing the pointer.)
So this change fixes it up as the from_raw binding came in in -rc1.
The other change is a .mailmap update.
Both have been in linux-next for a while with no reported issues"
* tag 'driver-core-6.12-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
mailmap: update mail for Fiona Behrens
rust: device: change the from_raw() function
This adds a simple seq file abstraction that lets you print to a seq
file using ordinary Rust printing syntax.
An example user from Rust Binder:
pub(crate) fn full_debug_print(
&self,
m: &SeqFile,
owner_inner: &mut ProcessInner,
) -> Result<()> {
let prio = self.node_prio();
let inner = self.inner.access_mut(owner_inner);
seq_print!(
m,
" node {}: u{:016x} c{:016x} pri {}:{} hs {} hw {} cs {} cw {}",
self.debug_id,
self.ptr,
self.cookie,
prio.sched_policy,
prio.prio,
inner.strong.has_count,
inner.weak.has_count,
inner.strong.count,
inner.weak.count,
);
if !inner.refs.is_empty() {
seq_print!(m, " proc");
for node_ref in &inner.refs {
seq_print!(m, " {}", node_ref.process.task.pid());
}
}
seq_print!(m, "\n");
for t in &inner.oneway_todo {
t.debug_print_inner(m, " pending async transaction ");
}
Ok(())
}
The `SeqFile` type is marked not thread safe so that `call_printf` can
be a `&self` method. The alternative is to use `self: Pin<&mut Self>`
which is inconvenient, or to have `SeqFile` wrap a pointer instead of
wrapping the C struct directly.
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20241001-seqfile-v1-1-dfcd0fc21e96@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
device_table in module_phy_driver macro is defined only when the
driver is built as a module. So a PHY driver imports phy::DeviceId
module in the following way then hits `unused import` warning when
it's compiled as built-in:
use kernel::net::phy::DeviceId;
kernel::module_phy_driver! {
drivers: [PhyQT2025],
device_table: [
DeviceId::new_with_driver::<PhyQT2025>(),
],
Put device_table in a const. It's not included in the kernel image if
unused (when the driver is compiled as built-in), and the compiler
doesn't complain.
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20240930134038.1309-1-fujita.tomonori@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The function Device::from_raw() increments a refcount by a call to
bindings::get_device(ptr). This can be confused because usually
from_raw() functions don't increment a refcount.
Hence, rename Device::from_raw() to avoid confuion with other "from_raw"
semantics.
The new name of function should be "get_device" to be consistent with
the function get_device() already exist in .c files.
This function body also changed, because the `into()` will convert the
`&'a Device` into `ARef<Device>` and also call `inc_ref` from the
`AlwaysRefCounted` trait implemented for Device.
Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Closes: https://github.com/Rust-for-Linux/linux/issues/1088
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Link: https://lore.kernel.org/r/20241001205603.106278-1-trintaeoitogc@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Starting with upstream Rust commit a5e3a3f9b6bd ("move
`manual_c_str_literals` to complexity"), to be released in Rust 1.83.0
[1], Clippy now warns on `manual_c_str_literals` by default, e.g.:
error: manually constructing a nul-terminated string
--> rust/kernel/kunit.rs:21:13
|
21 | b"\x013%pA\0".as_ptr() as _,
| ^^^^^^^^^^^^^ help: use a `c""` literal: `c"\x013%pA"`
|
= help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#manual_c_str_literals
= note: `-D clippy::manual-c-str-literals` implied by `-D warnings`
= help: to override `-D warnings` add `#[allow(clippy::manual_c_str_literals)]`
Apply the suggestion to clean up the warnings.
Link: https://github.com/rust-lang/rust-clippy/pull/13263 [1]
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Link: https://lore.kernel.org/r/20240927164414.560906-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The existing `CondVar` abstraction is a wrapper around
`wait_queue_head`, but it does not support all use-cases of the C
`wait_queue_head` type. To be specific, a `CondVar` cannot be registered
with a `struct poll_table`. This limitation has the advantage that you
do not need to call `synchronize_rcu` when destroying a `CondVar`.
However, we need the ability to register a `poll_table` with a
`wait_queue_head` in Rust Binder. To enable this, introduce a type
called `PollCondVar`, which is like `CondVar` except that you can
register a `poll_table`. We also introduce `PollTable`, which is a safe
wrapper around `poll_table` that is intended to be used with
`PollCondVar`.
The destructor of `PollCondVar` unconditionally calls `synchronize_rcu`
to ensure that the removal of epoll waiters has fully completed before
the `wait_queue_head` is destroyed.
That said, `synchronize_rcu` is rather expensive and is not needed in
all cases: If we have never registered a `poll_table` with the
`wait_queue_head`, then we don't need to call `synchronize_rcu`. (And
this is a common case in Binder - not all processes use Binder with
epoll.) The current implementation does not account for this, but if we
find that it is necessary to improve this, a future patch could store a
boolean next to the `wait_queue_head` to keep track of whether a
`poll_table` has ever been registered.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-8-88484f7a3dcf@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Adds a wrapper around `kuid_t` called `Kuid`. This allows us to define
various operations on kuids such as equality and current_euid. It also
lets us provide conversions from kuid into userspace values.
Rust Binder needs these operations because it needs to compare kuids for
equality, and it needs to tell userspace about the pid and uid of
incoming transactions.
To read kuids from a `struct task_struct`, you must currently use
various #defines that perform the appropriate field access under an RCU
read lock. Currently, we do not have a Rust wrapper for rcu_read_lock,
which means that for this patch, there are two ways forward:
1. Inline the methods into Rust code, and use __rcu_read_lock directly
rather than the rcu_read_lock wrapper. This gives up lockdep for
these usages of RCU.
2. Wrap the various #defines in helpers and call the helpers from Rust.
This patch uses the second option. One possible disadvantage of the
second option is the possible introduction of speculation gadgets, but
as discussed in [1], the risk appears to be acceptable.
Of course, once a wrapper for rcu_read_lock is available, it is
preferable to use that over either of the two above approaches.
Link: https://lore.kernel.org/all/202312080947.674CD2DC7@keescook/ [1]
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-7-88484f7a3dcf@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Allow for the creation of a file descriptor in two steps: first, we
reserve a slot for it, then we commit or drop the reservation. The first
step may fail (e.g., the current process ran out of available slots),
but commit and drop never fail (and are mutually exclusive).
This is needed by Rust Binder when fds are sent from one process to
another. It has to be a two-step process to properly handle the case
where multiple fds are sent: The operation must fail or succeed
atomically, which we achieve by first reserving the fds we need, and
only installing the files once we have reserved enough fds to send the
files.
Fd reservations assume that the value of `current` does not change
between the call to get_unused_fd_flags and the call to fd_install (or
put_unused_fd). By not implementing the Send trait, this abstraction
ensures that the `FileDescriptorReservation` cannot be moved into a
different process.
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-6-88484f7a3dcf@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add an abstraction for viewing the string representation of a security
context.
This is needed by Rust Binder because it has a feature where a process
can view the string representation of the security context for incoming
transactions. The process can use that to authenticate incoming
transactions, and since the feature is provided by the kernel, the
process can trust that the security context is legitimate.
This abstraction makes the following assumptions about the C side:
* When a call to `security_secid_to_secctx` is successful, it returns a
pointer and length. The pointer references a byte string and is valid
for reading for that many bytes.
* The string may be referenced until `security_release_secctx` is
called.
* If CONFIG_SECURITY is set, then the three methods mentioned in
rust/helpers are available without a helper. (That is, they are not a
#define or `static inline`.)
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-5-88484f7a3dcf@google.com
Acked-by: Paul Moore <paul@paul-moore.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Add a wrapper around `struct cred` called `Credential`, and provide
functionality to get the `Credential` associated with a `File`.
Rust Binder must check the credentials of processes when they attempt to
perform various operations, and these checks usually take a
`&Credential` as parameter. The security_binder_set_context_mgr function
would be one example. This patch is necessary to access these security_*
methods from Rust.
This Rust abstraction makes the following assumptions about the C side:
* `struct cred` is refcounted with `get_cred`/`put_cred`.
* It's okay to transfer a `struct cred` across threads, that is, you do
not need to call `put_cred` on the same thread as where you called
`get_cred`.
* The `euid` field of a `struct cred` never changes after
initialization.
* The `f_cred` field of a `struct file` never changes after
initialization.
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-4-88484f7a3dcf@google.com
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This abstraction makes it possible to manipulate the open files for a
process. The new `File` struct wraps the C `struct file`. When accessing
it using the smart pointer `ARef<File>`, the pointer will own a
reference count to the file. When accessing it as `&File`, then the
reference does not own a refcount, but the borrow checker will ensure
that the reference count does not hit zero while the `&File` is live.
Since this is intended to manipulate the open files of a process, we
introduce an `fget` constructor that corresponds to the C `fget`
method. In future patches, it will become possible to create a new fd in
a process and bind it to a `File`. Rust Binder will use these to send
fds from one process to another.
We also provide a method for accessing the file's flags. Rust Binder
will use this to access the flags of the Binder fd to check whether the
non-blocking flag is set, which affects what the Binder ioctl does.
This introduces a struct for the EBADF error type, rather than just
using the Error type directly. This has two advantages:
* `File::fget` returns a `Result<ARef<File>, BadFdError>`, which the
compiler will represent as a single pointer, with null being an error.
This is possible because the compiler understands that `BadFdError`
has only one possible value, and it also understands that the
`ARef<File>` smart pointer is guaranteed non-null.
* Additionally, we promise to users of the method that the method can
only fail with EBADF, which means that they can rely on this promise
without having to inspect its implementation.
That said, there are also two disadvantages:
* Defining additional error types involves boilerplate.
* The question mark operator will only utilize the `From` trait once,
which prevents you from using the question mark operator on
`BadFdError` in methods that return some third error type that the
kernel `Error` is convertible into. (However, it works fine in methods
that return `Error`.)
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Co-developed-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-3-88484f7a3dcf@google.com
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Introduces a safe function for getting a raw pointer to the current
task.
When writing bindings that need to access the current task, it is often
more convenient to call a method that directly returns a raw pointer
than to use the existing `Task::current` method. However, the only way
to do that is `bindings::get_current()` which is unsafe since it calls
into C. By introducing `Task::current_raw()`, it becomes possible to
obtain a pointer to the current task without using unsafe.
Link: https://lore.kernel.org/all/CAH5fLgjT48X-zYtidv31mox3C4_Ogoo_2cBOCmX0Ang3tAgGHA@mail.gmail.com/
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-2-88484f7a3dcf@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
This introduces a new marker type for types that shouldn't be thread
safe. By adding a field of this type to a struct, it becomes non-Send
and non-Sync, which means that it cannot be accessed in any way from
threads other than the one it was created on.
This is useful for APIs that require globals such as `current` to remain
constant while the value exists.
We update two existing users in the Kernel to use this helper:
* `Task::current()` - moving the return type of this value to a
different thread would not be safe as you can no longer be guaranteed
that the `current` pointer remains valid.
* Lock guards. Mutexes and spinlocks should be unlocked on the same
thread as where they were locked, so we enforce this using the Send
trait.
There are also additional users in later patches of this patchset. See
[1] and [2] for the discussion that led to the introduction of this
patch.
Link: https://lore.kernel.org/all/nFDPJFnzE9Q5cqY7FwSMByRH2OAn_BpI4H53NQfWIlN6I2qfmAqnkp2wRqn0XjMO65OyZY4h6P4K2nAGKJpAOSzksYXaiAK_FoH_8QbgBI4=@proton.me/ [1]
Link: https://lore.kernel.org/all/nFDPJFnzE9Q5cqY7FwSMByRH2OAn_BpI4H53NQfWIlN6I2qfmAqnkp2wRqn0XjMO65OyZY4h6P4K2nAGKJpAOSzksYXaiAK_FoH_8QbgBI4=@proton.me/ [2]
Suggested-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Reviewed-by: Björn Roy Baron <bjorn3_gh@protonmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240915-alice-file-v10-1-88484f7a3dcf@google.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
The `LockedBy::access` method only requires a shared reference to the
owner, so if we have shared access to the `LockedBy` from several
threads at once, then two threads could call `access` in parallel and
both obtain a shared reference to the inner value. Thus, require that
`T: Sync` when calling the `access` method.
An alternative is to require `T: Sync` in the `impl Sync for LockedBy`.
This patch does not choose that approach as it gives up the ability to
use `LockedBy` with `!Sync` types, which is okay as long as you only use
`access_mut`.
Cc: stable@vger.kernel.org
Fixes: 7b1f55e3a9 ("rust: sync: introduce `LockedBy`")
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Suggested-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240915-locked-by-sync-fix-v2-1-1a8d89710392@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Toolchain and infrastructure:
- Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up objtool
warnings), teach objtool about 'noreturn' Rust symbols and mimic
'___ADDRESSABLE()' for 'module_{init,exit}'. With that, we should be
objtool-warning-free, so enable it to run for all Rust object files.
- KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.
- Support 'RUSTC_VERSION', including re-config and re-build on change.
- Split helpers file into several files in a folder, to avoid conflicts
in it. Eventually those files will be moved to the right places with
the new build system. In addition, remove the need to manually export
the symbols defined there, reusing existing machinery for that.
- Relax restriction on configurations with Rust + GCC plugins to just
the RANDSTRUCT plugin.
'kernel' crate:
- New 'list' module: doubly-linked linked list for use with reference
counted values, which is heavily used by the upcoming Rust Binder.
This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
unique for the given ID), 'AtomicTracker' (tracks whether a 'ListArc'
exists using an atomic), 'ListLinks' (the prev/next pointers for an
item in a linked list), 'List' (the linked list itself), 'Iter' (an
iterator over a 'List'), 'Cursor' (a cursor into a 'List' that allows
to remove elements), 'ListArcField' (a field exclusively owned by a
'ListArc'), as well as support for heterogeneous lists.
- New 'rbtree' module: red-black tree abstractions used by the upcoming
Rust Binder. This includes 'RBTree' (the red-black tree itself),
'RBTreeNode' (a node), 'RBTreeNodeReservation' (a memory reservation
for a node), 'Iter' and 'IterMut' (immutable and mutable iterators),
'Cursor' (bidirectional cursor that allows to remove elements), as
well as an entry API similar to the Rust standard library one.
- 'init' module: add 'write_[pin_]init' methods and the 'InPlaceWrite'
trait. Add the 'assert_pinned!' macro.
- 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
introducing an associated type in the trait.
- 'alloc' module: add 'drop_contents' method to 'BoxExt'.
- 'types' module: implement the 'ForeignOwnable' trait for
'Pin<Box<T>>' and improve the trait's documentation. In addition,
add the 'into_raw' method to the 'ARef' type.
- 'error' module: in preparation for the upcoming Rust support for
32-bit architectures, like arm, locally allow Clippy lint for those.
Documentation:
- https://rust.docs.kernel.org has been announced, so link to it.
- Enable rustdoc's "jump to definition" feature, making its output a
bit closer to the experience in a cross-referencer.
- Debian Testing now also provides recent Rust releases (outside of
the freeze period), so add it to the list.
MAINTAINERS:
- Trevor is joining as reviewer of the "RUST" entry.
And a few other small bits.
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Merge tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux
Pull Rust updates from Miguel Ojeda:
"Toolchain and infrastructure:
- Support 'MITIGATION_{RETHUNK,RETPOLINE,SLS}' (which cleans up
objtool warnings), teach objtool about 'noreturn' Rust symbols and
mimic '___ADDRESSABLE()' for 'module_{init,exit}'. With that, we
should be objtool-warning-free, so enable it to run for all Rust
object files.
- KASAN (no 'SW_TAGS'), KCFI and shadow call sanitizer support.
- Support 'RUSTC_VERSION', including re-config and re-build on
change.
- Split helpers file into several files in a folder, to avoid
conflicts in it. Eventually those files will be moved to the right
places with the new build system. In addition, remove the need to
manually export the symbols defined there, reusing existing
machinery for that.
- Relax restriction on configurations with Rust + GCC plugins to just
the RANDSTRUCT plugin.
'kernel' crate:
- New 'list' module: doubly-linked linked list for use with reference
counted values, which is heavily used by the upcoming Rust Binder.
This includes 'ListArc' (a wrapper around 'Arc' that is guaranteed
unique for the given ID), 'AtomicTracker' (tracks whether a
'ListArc' exists using an atomic), 'ListLinks' (the prev/next
pointers for an item in a linked list), 'List' (the linked list
itself), 'Iter' (an iterator over a 'List'), 'Cursor' (a cursor
into a 'List' that allows to remove elements), 'ListArcField' (a
field exclusively owned by a 'ListArc'), as well as support for
heterogeneous lists.
- New 'rbtree' module: red-black tree abstractions used by the
upcoming Rust Binder.
This includes 'RBTree' (the red-black tree itself), 'RBTreeNode' (a
node), 'RBTreeNodeReservation' (a memory reservation for a node),
'Iter' and 'IterMut' (immutable and mutable iterators), 'Cursor'
(bidirectional cursor that allows to remove elements), as well as
an entry API similar to the Rust standard library one.
- 'init' module: add 'write_[pin_]init' methods and the
'InPlaceWrite' trait. Add the 'assert_pinned!' macro.
- 'sync' module: implement the 'InPlaceInit' trait for 'Arc' by
introducing an associated type in the trait.
- 'alloc' module: add 'drop_contents' method to 'BoxExt'.
- 'types' module: implement the 'ForeignOwnable' trait for
'Pin<Box<T>>' and improve the trait's documentation. In addition,
add the 'into_raw' method to the 'ARef' type.
- 'error' module: in preparation for the upcoming Rust support for
32-bit architectures, like arm, locally allow Clippy lint for
those.
Documentation:
- https://rust.docs.kernel.org has been announced, so link to it.
- Enable rustdoc's "jump to definition" feature, making its output a
bit closer to the experience in a cross-referencer.
- Debian Testing now also provides recent Rust releases (outside of
the freeze period), so add it to the list.
MAINTAINERS:
- Trevor is joining as reviewer of the "RUST" entry.
And a few other small bits"
* tag 'rust-6.12' of https://github.com/Rust-for-Linux/linux: (54 commits)
kasan: rust: Add KASAN smoke test via UAF
kbuild: rust: Enable KASAN support
rust: kasan: Rust does not support KHWASAN
kbuild: rust: Define probing macros for rustc
kasan: simplify and clarify Makefile
rust: cfi: add support for CFI_CLANG with Rust
cfi: add CONFIG_CFI_ICALL_NORMALIZE_INTEGERS
rust: support for shadow call stack sanitizer
docs: rust: include other expressions in conditional compilation section
kbuild: rust: replace proc macros dependency on `core.o` with the version text
kbuild: rust: rebuild if the version text changes
kbuild: rust: re-run Kconfig if the version text changes
kbuild: rust: add `CONFIG_RUSTC_VERSION`
rust: avoid `box_uninit_write` feature
MAINTAINERS: add Trevor Gross as Rust reviewer
rust: rbtree: add `RBTree::entry`
rust: rbtree: add cursor
rust: rbtree: add mutable iterator
rust: rbtree: add iterator
rust: rbtree: add red-black tree implementation backed by the C version
...
This mirrors the entry API [1] from the Rust standard library on
`RBTree`. This API can be used to access the entry at a specific key and
make modifications depending on whether the key is vacant or occupied.
This API is useful because it can often be used to avoid traversing the
tree multiple times.
This is used by binder to look up and conditionally access or insert a
value, depending on whether it is there or not [2].
Link: https://doc.rust-lang.org/stable/std/collections/btree_map/enum.Entry.html [1]
Link: https://android-review.googlesource.com/c/kernel/common/+/2849906 [2]
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-5-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add a cursor interface to `RBTree`, supporting the following use cases:
- Inspect the current node pointed to by the cursor, inspect/move to
it's neighbors in sort order (bidirectionally).
- Mutate the tree itself by removing the current node pointed to by the
cursor, or one of its neighbors.
Add functions to obtain a cursor to the tree by key:
- The node with the smallest key
- The node with the largest key
- The node matching the given key, or the one with the next larger key
The cursor abstraction is needed by the binder driver to efficiently
search for nodes and (conditionally) modify them, as well as their
neighbors [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-6-08ba9197f637@google.com/ [1]
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-4-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add mutable Iterator implementation for `RBTree`,
allowing iteration over (key, value) pairs in key order. Only values are
mutable, as mutating keys implies modifying a node's position in the tree.
Mutable iteration is used by the binder driver during shutdown to
clean up the tree maintained by the "range allocator" [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-6-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-3-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
- Add Iterator implementation for `RBTree`, allowing
iteration over (key, value) pairs in key order.
- Add individual `keys()` and `values()` functions to iterate over keys
or values alone.
- Update doctests to use iteration instead of explicitly getting items.
Iteration is needed by the binder driver to enumerate all values in a
tree for oneway spam detection [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-17-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-2-014561758a57@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The rust rbtree exposes a map-like interface over keys and values,
backed by the kernel red-black tree implementation. Values can be
inserted, deleted, and retrieved from a `RBTree` by key.
This base abstraction is used by binder to store key/value
pairs and perform lookups, for example the patch
"[PATCH RFC 03/20] rust_binder: add threading support"
in the binder RFC [1].
Link: https://lore.kernel.org/rust-for-linux/20231101-rust-binder-v1-3-08ba9197f637@google.com/ [1]
Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Tested-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Matt Gilbride <mattgilbride@google.com>
Link: https://lore.kernel.org/r/20240822-b4-rbtree-v12-1-014561758a57@google.com
[ Updated link to docs.kernel.org. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add unified genphy_read_status function for C22 and C45
registers. Instead of having genphy_c22 and genphy_c45 methods, this
unifies genphy_read_status functions for C22 and C45.
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add the unified read/write API for C22 and C45 registers. The
abstractions support access to only C22 registers now. Instead of
adding read/write_c45 methods specifically for C45, a new reg module
supports the unified API to access C22 and C45 registers with trait,
by calling an appropriate phylib functions.
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Implement AsRef<kernel::device::Device> trait for Device. A PHY driver
needs a reference to device::Device to call the firmware API.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Support phy_driver probe callback, used to set up device-specific
structures.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add rust equivalent to include/linux/sizes.h, makes code more
readable. Only SZ_*K that QT2025 PHY driver uses are added.
Make generated constants accessible with a proper type.
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
Signed-off-by: FUJITA Tomonori <fujita.tomonori@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Upstream Rust's libs-api team has consensus for stabilizing some of
`feature(new_uninit)`, but not for `Box<MaybeUninit<T>>::write`. Instead,
we can use `MaybeUninit<T>::write`, so Rust for Linux can drop the
feature after stabilization. That will happen after merging, as the FCP
has completed [1].
This is required before stabilization because remaining-unstable API
will be divided into new features. This code doesn't know about those
yet. It can't: they haven't landed, as the relevant PR is blocked on
rustc's CI testing Rust-for-Linux without this patch.
[ The PR has landed [2] and will be released in Rust 1.82.0 (expected on
2024-10-17), so we could conditionally enable the new unstable feature
(`box_uninit_write` [3]) instead, but just for a single `unsafe` block
it is probably not worth it. For the time being, I added it to the
"nice to have" section of our unstable features list. - Miguel ]
Link: https://github.com/rust-lang/rust/issues/63291#issuecomment-2183022955 [1]
Link: https://github.com/rust-lang/rust/pull/129416 [2]
Link: https://github.com/rust-lang/rust/issues/129397 [3]
Signed-off-by: Jubilee Young <workingjubilee@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Trevor Gross <tmgross@umich.edu>
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add a method for `ARef` that is analogous to `Arc::into_raw`. It is the
inverse operation of `ARef::from_raw`, and allows you to convert the
`ARef` back into a raw pointer while retaining ownership of the
refcount.
This new function will be used by [1] for converting the type in an
`ARef` using `ARef::from_raw(ARef::into_raw(me).cast())`. Alice has
also needed the same function for other use-cases in the past, but [1]
is the first to go upstream.
This was implemented independently by Kartik and Alice. The two versions
were merged by Alice, so all mistakes are Alice's.
Link: https://lore.kernel.org/r/20240801-vma-v3-1-db6c1c0afda9@google.com [1]
Link: https://github.com/Rust-for-Linux/linux/issues/1044
Signed-off-by: Kartik Prajapati <kartikprajapati987@gmail.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
[ Reworded to correct the author reference and changed tag to Link
since it is not a bug. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Use links to docs.kernel.org instead of www.kernel.org/doc/html/latest
in the code documentation. The links are shorter and cleaner.
Link: https://github.com/Rust-for-Linux/linux/issues/1101
Signed-off-by: Michael Vetter <jubalh@iodoru.org>
[ Reworded slightly. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
One way to explain what `ListArc` does is that it controls exclusive
access to the prev/next pointer field in a refcounted object. The
feature of having a special reference to a refcounted object with
exclusive access to specific fields is useful for other things, so
provide a general utility for that.
This is used by Rust Binder to keep track of which processes have a
reference to a given node. This involves an object for each process/node
pair, that is referenced by both the process and the node. For some
fields in this object, only the process's reference needs to access
them (and it needs mutable access), so Binder uses a ListArc to give the
process's reference exclusive access.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-10-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Support linked lists that can hold many different structs at once. This
is generally done using trait objects. The main challenge is figuring
what the struct is given only a pointer to the ListLinks.
We do this by storing a pointer to the struct next to the ListLinks
field. The container_of operation will then just read that pointer. When
the type is a trait object, that pointer will be a fat pointer whose
metadata is a vtable that tells you what kind of struct it is.
Heterogeneous lists are heavily used by Rust Binder. There are a lot of
so-called todo lists containing various events that need to be delivered
to userspace next time userspace calls into the driver. And there are
quite a few different todo item types: incoming transaction, changes to
refcounts, death notifications, and more.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-9-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The cursor is very similar to the list iterator, but it has one
important feature that the iterator doesn't: it can be used to remove
items from the linked list.
This feature cannot be added to the iterator because the references you
get from the iterator are considered borrows of the original list,
rather than borrows of the iterator. This means that there's no way to
prevent code like this:
let item = iter.next();
iter.remove();
use(item);
If `iter` was a cursor instead of an iterator, then `item` will be
considered a borrow of `iter`. Since `remove` destroys `iter`, this
means that the borrow-checker will prevent uses of `item` after the call
to `remove`.
So there is a trade-off between supporting use in traditional for loops,
and supporting removal of elements as you iterate. Iterators and cursors
represents two different choices on that spectrum.
Rust Binder needs cursors for the list of death notifications that a
process is currently handling. When userspace tells Binder that it has
finished processing the death notification, Binder will iterate the list
to search for the relevant item and remove it.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-8-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Rust Binder has lists containing stuff such as all contexts or all
processes, and sometimes needs to iterate over them. This patch enables
Rust Binder to do that using a normal for loop.
The iterator returns the ArcBorrow type, so it is possible to grab a
refcount to values while iterating.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-7-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add the actual linked list itself.
The linked list uses the following design: The List type itself just has
a single pointer to the first element of the list. And the actual list
items then form a cycle. So the last item is `first->prev`.
This is slightly different from the usual kernel linked list. Matching
that exactly would amount to giving List two pointers, and having it be
part of the cycle of items. This alternate design has the advantage that
the cycle is never completely empty, which can reduce the number of
branches in some cases. However, it also has the disadvantage that List
must be pinned, which this design is trying to avoid.
Having the list items form a cycle rather than having null pointers at
the beginning/end is convenient for several reasons. For one, it lets us
store only one pointer in List, and it simplifies the implementation of
several functions.
Unfortunately, the `remove` function that removes an arbitrary element
from the list has to be unsafe. This is needed because there is no way
to handle the case where you pass an element from the wrong list. For
example, if it is the first element of some other list, then that other
list's `first` pointer would not be updated. Similarly, it could be a
data race if you try to remove it from two different lists in parallel.
(There's no problem with passing `remove` an item that's not in any
list. Additionally, other removal methods such as `pop_front` need not
be unsafe, as they can't be used to remove items from another list.)
A future patch in this series will introduce support for cursors that
can be used to remove arbitrary items without unsafe code.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-6-f5f5e8075da0@google.com
[ Fixed a few typos. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Adds a macro for safely implementing the ListItem trait. As part of the
implementation of the macro, we also provide a HasListLinks trait
similar to the workqueue's HasWorkItem trait.
The HasListLinks trait is only necessary if you are implementing
ListItem using the impl_list_item macro.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-5-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Define the ListLinks struct, which wraps the prev/next pointers that
will be used to insert values into a List in a future patch. Also
define the ListItem trait, which is implemented by structs that have a
ListLinks field.
The ListItem trait provides four different methods that are all
essentially container_of or the reverse of container_of. Two of them are
used before inserting/after removing an item from the list, and the two
others are used when looking at a value without changing whether it is
in a list. This distinction is introduced because it is needed for the
patch that adds support for heterogeneous lists, which are implemented
by adding a third pointer field with a fat pointer to the full struct.
When inserting into the heterogeneous list, the pointer-to-self is
updated to have the right vtable, and the container_of operation is
implemented by just returning that pointer instead of using the real
container_of operation.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-4-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add the ability to track whether a ListArc exists for a given value,
allowing for the creation of ListArcs without going through UniqueArc.
The `impl_list_arc_safe!` macro is extended with a `tracked_by` strategy
that defers the tracking of ListArcs to a field of the struct.
Additionally, the AtomicListArcTracker type is introduced, which can
track whether a ListArc exists using an atomic. By deferring the
tracking to a field of type AtomicListArcTracker, structs gain the
ability to create ListArcs without going through a UniqueArc.
Rust Binder uses this for some objects where we want to be able to
insert them into a linked list at any time. Using the
AtomicListArcTracker, we are able to check whether an item is already in
the list, and if not, we can create a `ListArc` and push it.
The macro has the ability to defer the tracking of ListArcs to a field,
using whatever strategy that field has. Since we don't add any
strategies other than AtomicListArcTracker, another similar option would
be to hard-code that the field should be an AtomicListArcTracker.
However, Rust Binder has a case where the AtomicListArcTracker is not
stored directly in the struct, but in a sub-struct. Furthermore, the
outer struct is generic:
struct Wrapper<T: ?Sized> {
links: ListLinks,
inner: T,
}
Here, the Wrapper struct implements ListArcSafe with `tracked_by inner`,
and then the various types used with `inner` also uses the macro to
implement ListArcSafe. Some of them use the untracked strategy, and some
of them use tracked_by with an AtomicListArcTracker. This way, Wrapper
just inherits whichever choice `inner` has made.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-3-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
The `ListArc` type can be thought of as a special reference to a
refcounted object that owns the permission to manipulate the
`next`/`prev` pointers stored in the refcounted object. By ensuring that
each object has only one `ListArc` reference, the owner of that
reference is assured exclusive access to the `next`/`prev` pointers.
When a `ListArc` is inserted into a `List`, the `List` takes ownership
of the `ListArc` reference.
There are various strategies for ensuring that a value has only one
`ListArc` reference. The simplest is to convert a `UniqueArc` into a
`ListArc`. However, the refcounted object could also keep track of
whether a `ListArc` exists using a boolean, which could allow for the
creation of new `ListArc` references from an `Arc` reference. Whatever
strategy is used, the relevant tracking is referred to as "the tracking
inside `T`", and the `ListArcSafe` trait (and its subtraits) are used to
update the tracking when a `ListArc` is created or destroyed.
Note that we allow the case where the tracking inside `T` thinks that a
`ListArc` exists, but actually, there isn't a `ListArc`. However, we do
not allow the opposite situation where a `ListArc` exists, but the
tracking thinks it doesn't. This is because the former can at most
result in us failing to create a `ListArc` when the operation could
succeed, whereas the latter can result in the creation of two `ListArc`
references. Only the latter situation can lead to memory safety issues.
This patch introduces the `impl_list_arc_safe!` macro that allows you to
implement `ListArcSafe` for types using the strategy where a `ListArc`
can only be created from a `UniqueArc`. Other strategies are introduced
in later patches.
This is part of the linked list that Rust Binder will use for many
different things. The strategy where a `ListArc` can only be created
from a `UniqueArc` is actually sufficient for most of the objects that
Rust Binder needs to insert into linked lists. Usually, these are todo
items that are created and then immediately inserted into a queue.
The const generic ID allows objects to have several prev/next pointer
pairs so that the same object can be inserted into several different
lists. You are able to have several `ListArc` references as long as they
correspond to different pointer pairs. The ID itself is purely a
compile-time concept and will not be present in the final binary. Both
the `List` and the `ListArc` will need to agree on the ID for them to
work together. Rust Binder uses this in a few places (e.g. death
recipients) where the same object can be inserted into both generic todo
lists and some other lists for tracking the status of the object.
The ID is a const generic rather than a type parameter because the
`pair_from_unique` method needs to be able to assert that the two ids
are different. There's no easy way to assert that when using types
instead of integers.
Reviewed-by: Benno Lossin <benno.lossin@proton.me>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-2-f5f5e8075da0@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Add a macro to statically check if a field of a struct is marked with
`#[pin]` ie that it is structurally pinned. This can be used when
`unsafe` code needs to rely on fields being structurally pinned.
The macro has a special "inline" mode for the case where the type
depends on generic parameters from the surrounding scope.
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240814-linked-list-v5-1-f5f5e8075da0@google.com
[ Replaced `compile_fail` with `ignore` and a TODO note. Removed
`pub` from example to clean `unreachable_pub` lint. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Sometimes it is necessary to split allocation and initialization into
two steps. One such situation is when reusing existing allocations
obtained via `Box::drop_contents`. See [1] for an example.
In order to support this use case add `write_[pin_]init` functions to the
pin-init API. These functions operate on already allocated smart
pointers that wrap `MaybeUninit<T>`.
Link: https://lore.kernel.org/rust-for-linux/f026532f-8594-4f18-9aa5-57ad3f5bc592@proton.me/ [1]
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://lore.kernel.org/r/20240819112415.99810-2-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Sometimes (see [1]) it is necessary to drop the value inside of a
`Box<T>`, but retain the allocation. For example to reuse the allocation
in the future.
Introduce a new function `drop_contents` that turns a `Box<T>` into
`Box<MaybeUninit<T>>` by dropping the value.
Link: https://lore.kernel.org/rust-for-linux/20240418-b4-rbtree-v3-5-323e134390ce@google.com/ [1]
Signed-off-by: Benno Lossin <benno.lossin@proton.me>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://lore.kernel.org/r/20240819112415.99810-1-benno.lossin@proton.me
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
