* [PATCH v7 1/3] rust: net: add rust/kernel/net to NETWORKING [GENERAL]
2026-07-07 10:06 [PATCH v7 0/3] Rust netlink support + use in Rust Binder Alice Ryhl
@ 2026-07-07 10:06 ` Alice Ryhl
2026-07-07 10:06 ` [PATCH v7 2/3] rust: netlink: add raw netlink abstraction Alice Ryhl
2026-07-07 10:06 ` [PATCH v7 3/3] rust_binder: report netlink transactions Alice Ryhl
2 siblings, 0 replies; 4+ messages in thread
From: Alice Ryhl @ 2026-07-07 10:06 UTC (permalink / raw)
To: Carlos Llamas, Greg Kroah-Hartman, Andrew Lunn, Donald Hunter,
Jakub Kicinski, David S. Miller, Eric Dumazet, Paolo Abeni,
Simon Horman, Matthew Maurer
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Trevor Gross, Danilo Krummrich,
Christian Brauner, linux-kernel, rust-for-linux, netdev,
Alice Ryhl
To ensure that networking code can be found in a single shared place,
add it to the relevant NETWORKING entry. The net.rs file is moved into
the net/ directory so that it's included under the MAINTAINERS entry
without needing a separate rust/kernel/net.rs entry.
Reviewed-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
MAINTAINERS | 2 ++
rust/kernel/{net.rs => net/mod.rs} | 0
2 files changed, 2 insertions(+)
diff --git a/MAINTAINERS b/MAINTAINERS
index 15011f5752a9..303a06da4279 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18849,6 +18849,8 @@ F: include/uapi/linux/sctp.h
F: lib/net_utils.c
F: lib/random32.c
F: net/
+F: rust/helpers/net/
+F: rust/kernel/net/
F: samples/pktgen/
F: tools/net/
F: tools/testing/selftests/net/
diff --git a/rust/kernel/net.rs b/rust/kernel/net/mod.rs
similarity index 100%
rename from rust/kernel/net.rs
rename to rust/kernel/net/mod.rs
--
2.55.0.rc2.803.g1fd1e6609c-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v7 2/3] rust: netlink: add raw netlink abstraction
2026-07-07 10:06 [PATCH v7 0/3] Rust netlink support + use in Rust Binder Alice Ryhl
2026-07-07 10:06 ` [PATCH v7 1/3] rust: net: add rust/kernel/net to NETWORKING [GENERAL] Alice Ryhl
@ 2026-07-07 10:06 ` Alice Ryhl
2026-07-07 10:06 ` [PATCH v7 3/3] rust_binder: report netlink transactions Alice Ryhl
2 siblings, 0 replies; 4+ messages in thread
From: Alice Ryhl @ 2026-07-07 10:06 UTC (permalink / raw)
To: Carlos Llamas, Greg Kroah-Hartman, Andrew Lunn, Donald Hunter,
Jakub Kicinski, David S. Miller, Eric Dumazet, Paolo Abeni,
Simon Horman, Matthew Maurer
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Trevor Gross, Danilo Krummrich,
Christian Brauner, linux-kernel, rust-for-linux, netdev,
Alice Ryhl
This implements a safe and relatively simple API over the netlink API,
that allows you to add different attributes to a netlink message and
broadcast it. As the first user of this API only makes use of broadcast,
only broadcast messages are supported here.
This API is intended to be safe and to be easy to use in *generated*
code. This is because netlink is generally used with yaml files that
describe the underlying API, and the python generator outputs C code
(or, soon, Rust code) that lets you use the API more easily. So for
example, if there is a string field, the code generator will output a
method that internall calls `put_string()` with the right attr type.
Reviewed-by: Matthew Maurer <mmaurer@google.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
rust/bindings/bindings_helper.h | 3 +
rust/helpers/helpers.c | 1 +
rust/helpers/net/genetlink.c | 46 ++++++
rust/kernel/net/mod.rs | 2 +
rust/kernel/net/netlink.rs | 337 ++++++++++++++++++++++++++++++++++++++++
5 files changed, 389 insertions(+)
diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h
index 1124785e210b..ec96e811610d 100644
--- a/rust/bindings/bindings_helper.h
+++ b/rust/bindings/bindings_helper.h
@@ -93,6 +93,8 @@
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <linux/xarray.h>
+#include <net/genetlink.h>
+#include <net/netlink.h>
#include <trace/events/rust_sample.h>
/*
@@ -110,6 +112,7 @@
const size_t RUST_CONST_HELPER_ARCH_SLAB_MINALIGN = ARCH_SLAB_MINALIGN;
const size_t RUST_CONST_HELPER_ARCH_KMALLOC_MINALIGN = ARCH_KMALLOC_MINALIGN;
const size_t RUST_CONST_HELPER_PAGE_SIZE = PAGE_SIZE;
+const size_t RUST_CONST_HELPER_GENLMSG_DEFAULT_SIZE = GENLMSG_DEFAULT_SIZE;
const gfp_t RUST_CONST_HELPER_GFP_ATOMIC = GFP_ATOMIC;
const gfp_t RUST_CONST_HELPER_GFP_KERNEL = GFP_KERNEL;
const gfp_t RUST_CONST_HELPER_GFP_KERNEL_ACCOUNT = GFP_KERNEL_ACCOUNT;
diff --git a/rust/helpers/helpers.c b/rust/helpers/helpers.c
index 998e31052e66..1d4ee51f576b 100644
--- a/rust/helpers/helpers.c
+++ b/rust/helpers/helpers.c
@@ -72,6 +72,7 @@
#include "maple_tree.c"
#include "mm.c"
#include "mutex.c"
+#include "net/genetlink.c"
#include "of.c"
#include "page.c"
#include "pci.c"
diff --git a/rust/helpers/net/genetlink.c b/rust/helpers/net/genetlink.c
new file mode 100644
index 000000000000..3530b69f6cf7
--- /dev/null
+++ b/rust/helpers/net/genetlink.c
@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * Copyright (C) 2026 Google LLC.
+ */
+
+#include <net/genetlink.h>
+
+#ifdef CONFIG_NET
+
+__rust_helper struct sk_buff *rust_helper_genlmsg_new(size_t payload, gfp_t flags)
+{
+ return genlmsg_new(payload, flags);
+}
+
+__rust_helper
+int rust_helper_genlmsg_multicast(const struct genl_family *family,
+ struct sk_buff *skb, u32 portid,
+ unsigned int group, gfp_t flags)
+{
+ return genlmsg_multicast(family, skb, portid, group, flags);
+}
+
+__rust_helper void rust_helper_genlmsg_cancel(struct sk_buff *skb, void *hdr)
+{
+ genlmsg_cancel(skb, hdr);
+}
+
+__rust_helper void rust_helper_genlmsg_end(struct sk_buff *skb, void *hdr)
+{
+ genlmsg_end(skb, hdr);
+}
+
+__rust_helper void rust_helper_nlmsg_free(struct sk_buff *skb)
+{
+ nlmsg_free(skb);
+}
+
+__rust_helper
+int rust_helper_genl_has_listeners(const struct genl_family *family,
+ struct net *net, unsigned int group)
+{
+ return genl_has_listeners(family, net, group);
+}
+
+#endif
diff --git a/rust/kernel/net/mod.rs b/rust/kernel/net/mod.rs
index fe415cb369d3..8ecae7577ed2 100644
--- a/rust/kernel/net/mod.rs
+++ b/rust/kernel/net/mod.rs
@@ -4,3 +4,5 @@
#[cfg(CONFIG_RUST_PHYLIB_ABSTRACTIONS)]
pub mod phy;
+
+pub mod netlink;
diff --git a/rust/kernel/net/netlink.rs b/rust/kernel/net/netlink.rs
new file mode 100644
index 000000000000..22ef3dde36fa
--- /dev/null
+++ b/rust/kernel/net/netlink.rs
@@ -0,0 +1,337 @@
+// SPDX-License-Identifier: GPL-2.0
+
+// Copyright (C) 2026 Google LLC.
+
+//! Rust support for generic netlink.
+//!
+//! Currently only supports exposing multicast groups.
+//!
+//! C header: [`include/net/genetlink.h`](srctree/include/net/genetlink.h)
+
+use kernel::{
+ alloc::{self, AllocError},
+ error::to_result,
+ prelude::*,
+ transmute::AsBytes,
+ types::Opaque,
+ ThisModule,
+};
+
+use core::{
+ mem::ManuallyDrop,
+ ptr::NonNull, //
+};
+
+/// The default netlink message size.
+pub const GENLMSG_DEFAULT_SIZE: usize = bindings::GENLMSG_DEFAULT_SIZE;
+
+/// A wrapper around `struct sk_buff` for generic netlink messages.
+///
+/// This type is intended to be specific for buffers used with netlink only, and other usecases for
+/// `struct sk_buff` are out-of-scope for this abstraction.
+///
+/// # Invariants
+///
+/// The pointer has ownership over a valid `sk_buff`.
+pub struct NetlinkSkBuff {
+ skb: NonNull<kernel::bindings::sk_buff>,
+}
+
+impl NetlinkSkBuff {
+ /// Creates a new `NetlinkSkBuff` with the given size.
+ pub fn new(size: usize, flags: alloc::Flags) -> Result<NetlinkSkBuff, AllocError> {
+ // SAFETY: `genlmsg_new` only requires its arguments to be valid integers.
+ let skb = unsafe { bindings::genlmsg_new(size, flags.as_raw()) };
+ let skb = NonNull::new(skb).ok_or(AllocError)?;
+ Ok(NetlinkSkBuff { skb })
+ }
+
+ /// Puts a generic netlink header into the `NetlinkSkBuff`.
+ pub fn genlmsg_put(
+ self,
+ portid: u32,
+ seq: u32,
+ family: &'static Family,
+ cmd: u8,
+ ) -> Result<GenlMsg, AllocError> {
+ let skb = self.skb.as_ptr();
+ // SAFETY: The skb and family pointers are valid.
+ let hdr = unsafe { bindings::genlmsg_put(skb, portid, seq, family.as_raw(), 0, cmd) };
+ let hdr = NonNull::new(hdr).ok_or(AllocError)?;
+ Ok(GenlMsg { skb: self, hdr })
+ }
+}
+
+impl Drop for NetlinkSkBuff {
+ fn drop(&mut self) {
+ // SAFETY: We have ownership over the `sk_buff`, so we may free it.
+ unsafe { bindings::nlmsg_free(self.skb.as_ptr()) }
+ }
+}
+
+/// A generic netlink message being constructed.
+///
+/// # Invariants
+///
+/// `hdr` references the header in this netlink message.
+pub struct GenlMsg {
+ skb: NetlinkSkBuff,
+ hdr: NonNull<c_void>,
+}
+
+impl GenlMsg {
+ /// Puts an attribute into the message.
+ #[inline]
+ fn put<T>(&mut self, attrtype: c_int, value: &T) -> Result
+ where
+ T: ?Sized + AsBytes,
+ {
+ let skb = self.skb.skb.as_ptr();
+ let len = size_of_val(value);
+ let ptr = core::ptr::from_ref(value).cast::<c_void>();
+ // SAFETY: `skb` is valid by `NetlinkSkBuff` type invariants, and the provided value is
+ // readable and initialized for its `size_of` bytes.
+ to_result(unsafe { bindings::nla_put(skb, attrtype, len as c_int, ptr) })
+ }
+
+ /// Puts a `u32` attribute into the message.
+ #[inline]
+ pub fn put_u32(&mut self, attrtype: c_int, value: u32) -> Result {
+ self.put(attrtype, &value)
+ }
+
+ /// Puts a string attribute into the message.
+ #[inline]
+ pub fn put_string(&mut self, attrtype: c_int, value: &CStr) -> Result {
+ self.put(attrtype, value.to_bytes_with_nul())
+ }
+
+ /// Puts a flag attribute into the message.
+ #[inline]
+ pub fn put_flag(&mut self, attrtype: c_int) -> Result {
+ let skb = self.skb.skb.as_ptr();
+ // SAFETY: `skb` is valid by `NetlinkSkBuff` type invariants, and a null pointer is valid
+ // when the length is zero.
+ to_result(unsafe { bindings::nla_put(skb, attrtype, 0, core::ptr::null()) })
+ }
+
+ /// Sends the generic netlink message as a multicast message.
+ #[inline]
+ pub fn multicast(
+ self,
+ family: &'static Family,
+ portid: u32,
+ group: u32,
+ flags: alloc::Flags,
+ ) -> Result {
+ let me = ManuallyDrop::new(self);
+ // SAFETY: The `skb` and `family` pointers are valid. We pass ownership of the `skb` to
+ // `genlmsg_multicast` by not dropping `self`.
+ unsafe {
+ bindings::genlmsg_end(me.skb.skb.as_ptr(), me.hdr.as_ptr());
+ to_result(bindings::genlmsg_multicast(
+ family.as_raw(),
+ me.skb.skb.as_ptr(),
+ portid,
+ group,
+ flags.as_raw(),
+ ))
+ }
+ }
+}
+impl Drop for GenlMsg {
+ fn drop(&mut self) {
+ // SAFETY: The `hdr` pointer references the header of this generic netlink message.
+ unsafe { bindings::genlmsg_cancel(self.skb.skb.as_ptr(), self.hdr.as_ptr()) };
+ }
+}
+
+/// Flags for a generic netlink family.
+struct FamilyFlags {
+ /// Whether the family supports network namespaces.
+ netnsok: bool,
+ /// Whether the family supports parallel operations.
+ parallel_ops: bool,
+}
+
+impl FamilyFlags {
+ /// Converts the flags to the bitfield representation used by `genl_family`.
+ const fn into_bitfield(self) -> bindings::__BindgenBitfieldUnit<[u8; 1]> {
+ // The below shifts are verified correct by test_family_flags_bitfield() below.
+ //
+ // Although bindgen generates helpers to change bitfields based on the C headers, these
+ // helpers unfortunately can't be used in const context. Since `Family` needs to be filled
+ // out at build-time, we use this helper instead.
+ let mut bits = 0;
+ if self.netnsok {
+ bits |= 1 << 0;
+ }
+ if self.parallel_ops {
+ bits |= 1 << 1;
+ }
+ // Convert from little endian to the target's endianness.
+ bits = u8::from_le(bits);
+ // SAFETY: This bitfield is represented as an u8.
+ unsafe { core::mem::transmute::<u8, bindings::__BindgenBitfieldUnit<[u8; 1]>>(bits) }
+ }
+}
+
+/// A generic netlink family.
+#[repr(transparent)]
+pub struct Family {
+ inner: Opaque<bindings::genl_family>,
+}
+
+// SAFETY: The `Family` type is thread safe.
+unsafe impl Sync for Family {}
+
+impl Family {
+ /// Creates a new `Family` instance.
+ ///
+ /// Intended to be used from const context only. Will panic if provided with invalid arguments.
+ ///
+ /// The name must be a nul-terminated string, but it is taken as `&[u8]` so that it can be used
+ /// more conveniently with the strings generated by bindgen.
+ pub const fn const_new(
+ module: &ThisModule,
+ name: &[u8],
+ version: u32,
+ mcgrps: &'static [MulticastGroup],
+ ) -> Family {
+ let n_mcgrps = mcgrps.len() as u8;
+ if n_mcgrps as usize != mcgrps.len() {
+ panic!("too many mcgrps");
+ }
+ let mut genl_family = bindings::genl_family {
+ version,
+ _bitfield_1: FamilyFlags {
+ netnsok: true,
+ parallel_ops: true,
+ }
+ .into_bitfield(),
+ module: module.as_ptr(),
+ mcgrps: mcgrps.as_ptr().cast(),
+ n_mcgrps,
+ ..pin_init::zeroed()
+ };
+ if CStr::from_bytes_with_nul(name).is_err() {
+ panic!("genl_family name not nul-terminated");
+ }
+ if genl_family.name.len() < name.len() {
+ panic!("genl_family name too long");
+ }
+ let mut i = 0;
+ while i < name.len() {
+ genl_family.name[i] = name[i];
+ i += 1;
+ }
+ Family {
+ inner: Opaque::new(genl_family),
+ }
+ }
+
+ /// Checks if there are any listeners for the given multicast group.
+ pub fn has_listeners(&self, group: u32) -> bool {
+ // SAFETY: The family and init_net pointers are valid.
+ unsafe {
+ bindings::genl_has_listeners(self.as_raw(), &raw mut bindings::init_net, group) != 0
+ }
+ }
+
+ /// Returns a raw pointer to the underlying `genl_family` structure.
+ pub fn as_raw(&self) -> *mut bindings::genl_family {
+ self.inner.get()
+ }
+}
+
+/// A generic netlink multicast group.
+#[repr(transparent)]
+pub struct MulticastGroup {
+ // No Opaque because fully immutable
+ group: bindings::genl_multicast_group,
+}
+
+// SAFETY: Pure data so thread safe.
+unsafe impl Sync for MulticastGroup {}
+
+impl MulticastGroup {
+ /// Creates a new `MulticastGroup` instance.
+ ///
+ /// Intended to be used from const context only. Will panic if provided with invalid arguments.
+ pub const fn const_new(name: &CStr) -> MulticastGroup {
+ let mut group: bindings::genl_multicast_group = pin_init::zeroed();
+
+ let name = name.to_bytes_with_nul();
+ if group.name.len() < name.len() {
+ panic!("genl_multicast_group name too long");
+ }
+ let mut i = 0;
+ while i < name.len() {
+ group.name[i] = name[i];
+ i += 1;
+ }
+
+ MulticastGroup { group }
+ }
+}
+
+/// A registration of a generic netlink family.
+///
+/// This type represents the registration of a [`Family`]. When an instance of this type is
+/// dropped, its respective generic netlink family will be unregistered from the system.
+///
+/// # Invariants
+///
+/// `self.family` always holds a valid reference to an initialized and registered [`Family`].
+pub struct Registration {
+ family: &'static Family,
+}
+
+impl Family {
+ /// Registers the generic netlink family with the kernel.
+ pub fn register(&'static self) -> Result<Registration> {
+ // SAFETY: `self.as_raw()` is a valid pointer to a `genl_family` struct.
+ // The `genl_family` struct is static, so it will outlive the registration.
+ to_result(unsafe { bindings::genl_register_family(self.as_raw()) })?;
+ Ok(Registration { family: self })
+ }
+}
+
+impl Drop for Registration {
+ fn drop(&mut self) {
+ // SAFETY: `self.family.as_raw()` is a valid pointer to a registered `genl_family` struct.
+ // The `Registration` struct ensures that `genl_unregister_family` is called exactly once
+ // for this family when it goes out of scope.
+ unsafe { bindings::genl_unregister_family(self.family.as_raw()) };
+ }
+}
+
+#[macros::kunit_tests(rust_netlink)]
+mod tests {
+ use super::*;
+
+ #[test]
+ fn test_family_flags_bitfield() {
+ for netnsok in [false, true] {
+ for parallel_ops in [false, true] {
+ let mut b_fam = bindings::genl_family {
+ ..Default::default()
+ };
+ b_fam.set_netnsok(if netnsok { 1 } else { 0 });
+ b_fam.set_parallel_ops(if parallel_ops { 1 } else { 0 });
+
+ let c_bitfield = FamilyFlags {
+ netnsok,
+ parallel_ops,
+ }
+ .into_bitfield();
+
+ // SAFETY: The bit field is stored as u8.
+ let b_val: u8 = unsafe { core::mem::transmute(b_fam._bitfield_1) };
+ // SAFETY: The bit field is stored as u8.
+ let c_val: u8 = unsafe { core::mem::transmute(c_bitfield) };
+ assert_eq!(b_val, c_val);
+ }
+ }
+ }
+}
--
2.55.0.rc2.803.g1fd1e6609c-goog
^ permalink raw reply related [flat|nested] 4+ messages in thread* [PATCH v7 3/3] rust_binder: report netlink transactions
2026-07-07 10:06 [PATCH v7 0/3] Rust netlink support + use in Rust Binder Alice Ryhl
2026-07-07 10:06 ` [PATCH v7 1/3] rust: net: add rust/kernel/net to NETWORKING [GENERAL] Alice Ryhl
2026-07-07 10:06 ` [PATCH v7 2/3] rust: netlink: add raw netlink abstraction Alice Ryhl
@ 2026-07-07 10:06 ` Alice Ryhl
2 siblings, 0 replies; 4+ messages in thread
From: Alice Ryhl @ 2026-07-07 10:06 UTC (permalink / raw)
To: Carlos Llamas, Greg Kroah-Hartman, Andrew Lunn, Donald Hunter,
Jakub Kicinski, David S. Miller, Eric Dumazet, Paolo Abeni,
Simon Horman, Matthew Maurer
Cc: Miguel Ojeda, Boqun Feng, Gary Guo, Björn Roy Baron,
Benno Lossin, Andreas Hindborg, Trevor Gross, Danilo Krummrich,
Christian Brauner, linux-kernel, rust-for-linux, netdev,
Alice Ryhl
From: Carlos Llamas <cmllamas@google.com>
The Android Binder driver supports a netlink API that reports
transaction *failures* to a userspace daemon. This allows devices to
monitor processes with many failed transactions so that it can e.g. kill
misbehaving apps.
One very important thing that this monitors is when many oneway messages
are sent to a frozen process, so there is special handling to ensure
this scenario is surfaced over netlink.
Signed-off-by: Carlos Llamas <cmllamas@google.com>
Acked-by: Carlos Llamas <cmllamas@google.com>
Co-developed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
---
drivers/android/Kconfig | 2 +-
drivers/android/binder/netlink.rs | 117 +++++++++++++++++++++++++++++
drivers/android/binder/rust_binder_main.rs | 8 +-
drivers/android/binder/thread.rs | 11 ++-
drivers/android/binder/transaction.rs | 40 ++++++++++
rust/uapi/uapi_helper.h | 1 +
6 files changed, 175 insertions(+), 4 deletions(-)
diff --git a/drivers/android/Kconfig b/drivers/android/Kconfig
index e2e402c9d175..606a9d07f774 100644
--- a/drivers/android/Kconfig
+++ b/drivers/android/Kconfig
@@ -16,7 +16,7 @@ config ANDROID_BINDER_IPC
config ANDROID_BINDER_IPC_RUST
bool "Rust version of Android Binder IPC Driver"
- depends on RUST && MMU && !ANDROID_BINDER_IPC
+ depends on RUST && MMU && NET && !ANDROID_BINDER_IPC
help
This enables the Rust implementation of the Binder driver.
diff --git a/drivers/android/binder/netlink.rs b/drivers/android/binder/netlink.rs
new file mode 100644
index 000000000000..beb7ea2edaff
--- /dev/null
+++ b/drivers/android/binder/netlink.rs
@@ -0,0 +1,117 @@
+// SPDX-License-Identifier: ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)
+/* Based on: Documentation/netlink/specs/binder.yaml */
+
+#![allow(unreachable_pub, clippy::wrong_self_convention)]
+use kernel::{
+ net::netlink::{
+ Family,
+ GenlMsg,
+ MulticastGroup,
+ NetlinkSkBuff, //
+ },
+ prelude::*, //
+};
+
+pub static BINDER_NL_FAMILY: Family = Family::const_new(
+ &crate::THIS_MODULE,
+ kernel::uapi::BINDER_FAMILY_NAME,
+ kernel::uapi::BINDER_FAMILY_VERSION,
+ &BINDER_NL_FAMILY_MCGRPS,
+);
+
+static BINDER_NL_FAMILY_MCGRPS: [MulticastGroup; 1] = [MulticastGroup::const_new(c"report")];
+
+/// A multicast event sent to userspace subscribers to notify them about
+/// binder transaction failures. The generated report provides the full
+/// details of the specific transaction that failed. The intention is for
+/// programs to monitor these events and react to the failures as needed.
+pub struct Report {
+ skb: GenlMsg,
+}
+
+impl Report {
+ /// Create a new multicast message.
+ pub fn new(
+ size: usize,
+ portid: u32,
+ seq: u32,
+ flags: kernel::alloc::Flags,
+ ) -> Result<Self, kernel::alloc::AllocError> {
+ const BINDER_CMD_REPORT: u8 = kernel::uapi::BINDER_CMD_REPORT as u8;
+ let skb = NetlinkSkBuff::new(size, flags)?;
+ let skb = skb.genlmsg_put(portid, seq, &BINDER_NL_FAMILY, BINDER_CMD_REPORT)?;
+ Ok(Self { skb })
+ }
+
+ /// Broadcast this message.
+ pub fn multicast(self, portid: u32, flags: kernel::alloc::Flags) -> Result {
+ self.skb.multicast(&BINDER_NL_FAMILY, portid, 0, flags)
+ }
+
+ /// Check if this message type has listeners.
+ pub fn has_listeners() -> bool {
+ BINDER_NL_FAMILY.has_listeners(0)
+ }
+
+ /// The enum binder_driver_return_protocol returned to the sender.
+ pub fn error(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_ERROR: c_int = kernel::uapi::BINDER_A_REPORT_ERROR as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_ERROR, val)
+ }
+
+ /// The binder context where the transaction occurred.
+ pub fn context(&mut self, val: &CStr) -> Result {
+ const BINDER_A_REPORT_CONTEXT: c_int = kernel::uapi::BINDER_A_REPORT_CONTEXT as c_int;
+ self.skb.put_string(BINDER_A_REPORT_CONTEXT, val)
+ }
+
+ /// The PID of the sender process.
+ pub fn from_pid(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_FROM_PID: c_int = kernel::uapi::BINDER_A_REPORT_FROM_PID as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_FROM_PID, val)
+ }
+
+ /// The TID of the sender thread.
+ pub fn from_tid(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_FROM_TID: c_int = kernel::uapi::BINDER_A_REPORT_FROM_TID as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_FROM_TID, val)
+ }
+
+ /// The PID of the recipient process. This attribute may not be present
+ /// if the target could not be determined.
+ pub fn to_pid(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_TO_PID: c_int = kernel::uapi::BINDER_A_REPORT_TO_PID as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_TO_PID, val)
+ }
+
+ /// The TID of the recipient thread. This attribute may not be present
+ /// if the target could not be determined.
+ pub fn to_tid(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_TO_TID: c_int = kernel::uapi::BINDER_A_REPORT_TO_TID as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_TO_TID, val)
+ }
+
+ /// When present, indicates the failed transaction is a reply.
+ pub fn is_reply(&mut self) -> Result {
+ const BINDER_A_REPORT_IS_REPLY: c_int = kernel::uapi::BINDER_A_REPORT_IS_REPLY as c_int;
+ self.skb.put_flag(BINDER_A_REPORT_IS_REPLY)
+ }
+
+ /// The bitmask of enum transaction_flags from the transaction.
+ pub fn flags(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_FLAGS: c_int = kernel::uapi::BINDER_A_REPORT_FLAGS as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_FLAGS, val)
+ }
+
+ /// The application-defined code from the transaction.
+ pub fn code(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_CODE: c_int = kernel::uapi::BINDER_A_REPORT_CODE as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_CODE, val)
+ }
+
+ /// The transaction payload size in bytes.
+ pub fn data_size(&mut self, val: u32) -> Result {
+ const BINDER_A_REPORT_DATA_SIZE: c_int = kernel::uapi::BINDER_A_REPORT_DATA_SIZE as c_int;
+ self.skb.put_u32(BINDER_A_REPORT_DATA_SIZE, val)
+ }
+}
diff --git a/drivers/android/binder/rust_binder_main.rs b/drivers/android/binder/rust_binder_main.rs
index 432390aab25b..df47aba05133 100644
--- a/drivers/android/binder/rust_binder_main.rs
+++ b/drivers/android/binder/rust_binder_main.rs
@@ -32,6 +32,7 @@
mod deferred_close;
mod defs;
mod error;
+mod netlink;
mod node;
mod page_range;
mod process;
@@ -282,19 +283,22 @@ fn ptr_align(value: usize) -> Option<usize> {
// SAFETY: We call register in `init`.
static BINDER_SHRINKER: Shrinker = unsafe { Shrinker::new() };
-struct BinderModule {}
+struct BinderModule {
+ _netlink: kernel::net::netlink::Registration,
+}
impl kernel::Module for BinderModule {
fn init(_module: &'static kernel::ThisModule) -> Result<Self> {
// SAFETY: The module initializer never runs twice, so we only call this once.
unsafe { crate::context::CONTEXTS.init() };
+ let netlink = crate::netlink::BINDER_NL_FAMILY.register()?;
BINDER_SHRINKER.register(c"android-binder")?;
// SAFETY: The module is being loaded, so we can initialize binderfs.
unsafe { kernel::error::to_result(binderfs::init_rust_binderfs())? };
- Ok(Self {})
+ Ok(Self { _netlink: netlink })
}
}
diff --git a/drivers/android/binder/thread.rs b/drivers/android/binder/thread.rs
index 19f881948a84..33368f7fd551 100644
--- a/drivers/android/binder/thread.rs
+++ b/drivers/android/binder/thread.rs
@@ -1284,6 +1284,15 @@ fn transaction(self: &Arc<Self>, cmd: u32, reader: &mut UserSliceReader) -> Resu
}
}
+ if info.oneway_spam_suspect {
+ // If this is both a oneway spam suspect and a failure, we report it twice. This is
+ // useful in case the transaction failed with BR_TRANSACTION_PENDING_FROZEN.
+ info.report_netlink(BR_ONEWAY_SPAM_SUSPECT, &self.process.ctx);
+ }
+ if info.reply != 0 {
+ info.report_netlink(info.reply, &self.process.ctx);
+ }
+
Ok(())
}
@@ -1354,11 +1363,11 @@ fn reply_inner(self: &Arc<Self>, info: &mut TransactionInfo) -> BinderResult {
info.from_tid,
info.to_pid
);
-
let param = err.source.as_ref().map_or(0, |e| e.to_errno());
let ee = ExtendedError::new(info.debug_id as u32, err.reply, param);
orig.from
.deliver_reply(Err(BR_FAILED_REPLY), &orig, Some(ee));
+ info.reply = BR_FAILED_REPLY;
err.reply = BR_TRANSACTION_COMPLETE;
err
});
diff --git a/drivers/android/binder/transaction.rs b/drivers/android/binder/transaction.rs
index afef5b46eac2..6cb7b745c52e 100644
--- a/drivers/android/binder/transaction.rs
+++ b/drivers/android/binder/transaction.rs
@@ -3,6 +3,7 @@
// Copyright (C) 2025 Google LLC.
use kernel::{
+ net::netlink::GENLMSG_DEFAULT_SIZE,
prelude::*,
seq_file::SeqFile,
seq_print,
@@ -18,6 +19,7 @@
allocation::{Allocation, TranslatedFds},
defs::*,
error::{BinderError, BinderResult},
+ netlink::Report,
node::{Node, NodeRef},
process::{Process, ProcessInner},
ptr_align,
@@ -51,6 +53,44 @@ impl TransactionInfo {
pub(crate) fn is_oneway(&self) -> bool {
self.flags & TF_ONE_WAY != 0
}
+
+ pub(crate) fn report_netlink(&self, reply: u32, ctx: &crate::Context) {
+ if let Err(err) = self.report_netlink_inner(reply, ctx) {
+ pr_warn!(
+ "{}:{} netlink report failed: {err:?}\n",
+ self.from_pid,
+ self.from_tid
+ );
+ }
+ }
+
+ fn report_netlink_inner(&self, reply: u32, ctx: &crate::Context) -> kernel::error::Result {
+ if !Report::has_listeners() {
+ return Ok(());
+ }
+ let mut report = Report::new(GENLMSG_DEFAULT_SIZE, 0, 0, GFP_KERNEL)?;
+
+ report.error(reply)?;
+ report.context(&ctx.name)?;
+ report.from_pid(self.from_pid as u32)?;
+ report.from_tid(self.from_tid as u32)?;
+ if self.to_pid != 0 {
+ report.to_pid(self.to_pid as u32)?;
+ }
+ if self.to_tid != 0 {
+ report.to_tid(self.to_tid as u32)?;
+ }
+
+ if self.is_reply {
+ report.is_reply()?;
+ }
+ report.flags(self.flags)?;
+ report.code(self.code)?;
+ report.data_size(self.data_size as u32)?;
+
+ report.multicast(0, GFP_KERNEL)?;
+ Ok(())
+ }
}
use core::mem::offset_of;
diff --git a/rust/uapi/uapi_helper.h b/rust/uapi/uapi_helper.h
index 06d7d1a2e8da..86c7b6b284b0 100644
--- a/rust/uapi/uapi_helper.h
+++ b/rust/uapi/uapi_helper.h
@@ -11,6 +11,7 @@
#include <uapi/drm/nova_drm.h>
#include <uapi/drm/panthor_drm.h>
#include <uapi/linux/android/binder.h>
+#include <uapi/linux/android/binder_netlink.h>
#include <uapi/linux/mdio.h>
#include <uapi/linux/mii.h>
#include <uapi/linux/ethtool.h>
--
2.55.0.rc2.803.g1fd1e6609c-goog
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