Enable unwinding in userspace

.github/workflows/ci.yml

@@ -22,10 +22,12 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@master
+      - uses: dtolnay/rust-toolchain@nightly
         with:
-          toolchain: nightly
-          components: rustfmt, clippy, miri, rust-src
+          components: clippy,miri,rustfmt,rust-src
+
+      # Installed *after* nightly so it is the default.
+      - uses: dtolnay/rust-toolchain@stable
 
       - uses: Swatinem/rust-cache@v2
 
@@ -43,10 +45,10 @@ jobs:
         run: taplo fmt --check
 
       - name: Check formatting
-        run: cargo fmt --all -- --check
+        run: cargo +nightly fmt --all -- --check
 
       - name: Run clippy
-        run: cargo hack clippy --all-targets --feature-powerset --workspace -- --deny warnings
+        run: ./clippy.sh
 
       - run: cargo xtask public-api
         if: github.event_name == 'pull_request'
@@ -62,7 +64,7 @@ jobs:
       - name: Run miri
         run: |
           set -euxo pipefail
-          cargo hack miri test --all-targets --feature-powerset \
+          cargo +nightly hack miri test --all-targets --feature-powerset \
             --exclude aya-ebpf \
             --exclude aya-ebpf-bindings \
             --exclude aya-log-ebpf \
@@ -85,9 +87,7 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@master
-        with:
-          toolchain: stable
+      - uses: dtolnay/rust-toolchain@stable
 
       - uses: Swatinem/rust-cache@v2
 
@@ -149,11 +149,13 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
-      - uses: dtolnay/rust-toolchain@master
+      - uses: dtolnay/rust-toolchain@nightly
         with:
-          toolchain: nightly
           components: rust-src
 
+      # Installed *after* nightly so it is the default.
+      - uses: dtolnay/rust-toolchain@stable
+
       - uses: Swatinem/rust-cache@v2
 
       - name: bpf-linker
@@ -165,18 +167,21 @@ jobs:
           CARGO_CFG_BPF_TARGET_ARCH: ${{ matrix.bpf_target_arch }}
         run: |
           set -euxo pipefail
-          cargo hack build --package aya-ebpf --package aya-log-ebpf \
-            --feature-powerset \
+          cargo +nightly hack build \
             --target ${{ matrix.target }} \
-            -Z build-std=core
+            -Z build-std=core \
+            --package aya-ebpf \
+            --package aya-log-ebpf \
+            --feature-powerset
 
       - name: Test
         env:
           CARGO_CFG_BPF_TARGET_ARCH: ${{ matrix.bpf_target_arch }}
           RUST_BACKTRACE: full
         run: |
           set -euxo pipefail
-          cargo hack test --doc \
+          cargo hack test \
+            --doc \
             --package aya-ebpf \
             --package aya-log-ebpf \
             --feature-powerset
@@ -236,10 +241,13 @@ jobs:
           echo $(brew --prefix)/opt/gnu-tar/libexec/gnubin >> $GITHUB_PATH
           echo $(brew --prefix)/opt/llvm/bin >> $GITHUB_PATH
 
-      - uses: dtolnay/rust-toolchain@master
+      - uses: dtolnay/rust-toolchain@nightly
         with:
-          toolchain: nightly
           components: rust-src
+
+      # Installed *after* nightly so it is the default.
+      - uses: dtolnay/rust-toolchain@stable
+        with:
           targets: aarch64-unknown-linux-musl,x86_64-unknown-linux-musl
 
       - uses: Swatinem/rust-cache@v2

Cargo.toml

@@ -96,12 +96,6 @@ tokio = { version = "1.24.0", default-features = false }
 which = { version = "7.0.0", default-features = false }
 xdpilone = { version = "1.0.5", default-features = false }
 
-[profile.dev]
-panic = "abort"
-
-[profile.release]
-panic = "abort"
-
 [profile.release.package.integration-ebpf]
 debug = 2
 codegen-units = 1

clippy.sh

@@ -0,0 +1,12 @@
+#!/usr/bin/env sh
+
+# `-C panic=abort` because "unwinding panics are not supported without std";
+# integration-ebpf contains `#[no_std]` binaries.
+#
+# `-Zpanic_abort_tests` because "building tests with panic=abort is not supported without
+# `-Zpanic_abort_tests`"; Cargo does this automatically when panic=abort is set via profile
+# but we want to preserve unwinding at runtime - here we are just running clippy so we don't
+# care about unwinding behavior.
+#
+# `+nightly` because "the option `Z` is only accepted on the nightly compiler".
+exec cargo +nightly hack clippy "$@" --all-targets --feature-powerset --workspace -- --deny warnings -C panic=abort -Zpanic_abort_tests

ebpf/aya-ebpf/Cargo.toml

@@ -12,14 +12,6 @@ edition.workspace = true
 aya-ebpf-cty = { version = "^0.2.2", path = "../aya-ebpf-cty" }
 aya-ebpf-macros = { version = "^0.1.1", path = "../../aya-ebpf-macros" }
 aya-ebpf-bindings = { version = "^0.1.1", path = "../aya-ebpf-bindings" }
-const-assert = { workspace = true, optional = true }
 
 [build-dependencies]
 rustversion = { workspace = true }
-
-[features]
-default = []
-# TODO(https://github.com/rust-lang/rust/issues/76560): Always utilize the
-# logic gated behind this feature. This is not currently possible because the
-# underlying `const_generic_exprs` language feature is still incomplete.
-const_assert = ["const-assert"]

ebpf/aya-ebpf/src/lib.rs

@@ -8,11 +8,7 @@
     html_logo_url = "https://aya-rs.dev/assets/images/crabby.svg",
     html_favicon_url = "https://aya-rs.dev/assets/images/crabby.svg"
 )]
-#![cfg_attr(
-    feature = "const_assert",
-    allow(incomplete_features),
-    feature(generic_const_exprs)
-)]
+#![cfg_attr(unstable, allow(incomplete_features), feature(generic_const_exprs))]
 #![cfg_attr(unstable, feature(never_type))]
 #![cfg_attr(target_arch = "bpf", feature(asm_experimental_arch))]
 #![allow(clippy::missing_safety_doc)]

ebpf/aya-ebpf/src/maps/ring_buf.rs

@@ -5,9 +5,6 @@ use core::{
     ops::{Deref, DerefMut},
 };
 
-#[cfg(feature = "const_assert")]
-use const_assert::{Assert, IsTrue};
-
 use crate::{
     bindings::{bpf_map_def, bpf_map_type::BPF_MAP_TYPE_RINGBUF},
     helpers::{
@@ -17,6 +14,17 @@ use crate::{
     maps::PinningType,
 };
 
+#[cfg(unstable)]
+mod const_assert {
+    pub struct Assert<const COND: bool> {}
+
+    pub trait IsTrue {}
+
+    impl IsTrue for Assert<true> {}
+}
+#[cfg(unstable)]
+use const_assert::{Assert, IsTrue};
+
 #[repr(transparent)]
 pub struct RingBuf {
     def: UnsafeCell<bpf_map_def>,
@@ -93,7 +101,7 @@ impl RingBuf {
     /// Reserve memory in the ring buffer that can fit `T`.
     ///
     /// Returns `None` if the ring buffer is full.
-    #[cfg(feature = "const_assert")]
+    #[cfg(unstable)]
     pub fn reserve<T: 'static>(&self, flags: u64) -> Option<RingBufEntry<T>>
     where
         Assert<{ 8 % mem::align_of::<T>() == 0 }>: IsTrue,
@@ -109,7 +117,7 @@ impl RingBuf {
     /// be equal or smaller than 8. If you use this with a `T` that isn't properly aligned, this
     /// function will be compiled to a panic; depending on your panic_handler, this may make
     /// the eBPF program fail to load, or it may make it have undefined behavior.
-    #[cfg(not(feature = "const_assert"))]
+    #[cfg(not(unstable))]
     pub fn reserve<T: 'static>(&self, flags: u64) -> Option<RingBufEntry<T>> {
         assert_eq!(8 % mem::align_of::<T>(), 0);
         self.reserve_impl(flags)

test/integration-test/Cargo.toml

@@ -35,10 +35,6 @@ cargo_metadata = { workspace = true }
 # script to build this, but we want to teach cargo about the dependecy so that cache invalidation
 # works properly.
 #
-# Note also that https://github.com/rust-lang/cargo/issues/10593 occurs when `target = ...` is added
-# to an artifact dependency; it seems possible to work around that by setting `resolver = "1"` in
-# Cargo.toml in the workspace root.
-#
 # Finally note that *any* usage of `artifact = ...` in *any* Cargo.toml in the workspace breaks
 # workflows with stable cargo; stable cargo outright refuses to load manifests that use unstable
 # features.

test/integration-test/build.rs

@@ -56,15 +56,6 @@ fn main() {
     let out_dir = env::var_os("OUT_DIR").unwrap();
     let out_dir = PathBuf::from(out_dir);
 
-    let endian = env::var_os("CARGO_CFG_TARGET_ENDIAN").unwrap();
-    let target = if endian == "big" {
-        "bpfeb"
-    } else if endian == "little" {
-        "bpfel"
-    } else {
-        panic!("unsupported endian={:?}", endian)
-    };
-
     const C_BPF: &[(&str, bool)] = &[
         ("ext.bpf.c", false),
         ("iter.bpf.c", true),
@@ -76,6 +67,15 @@ fn main() {
     ];
 
     if build_integration_bpf {
+        let endian = env::var_os("CARGO_CFG_TARGET_ENDIAN").unwrap();
+        let target = if endian == "big" {
+            "bpfeb"
+        } else if endian == "little" {
+            "bpfel"
+        } else {
+            panic!("unsupported endian={:?}", endian)
+        };
+
         let libbpf_dir = manifest_dir
             .parent()
             .unwrap()
@@ -191,7 +191,10 @@ fn main() {
 
         let mut cmd = Command::new("cargo");
         cmd.args([
+            "+nightly",
             "build",
+            "--package",
+            "integration-ebpf",
             "-Z",
             "build-std=core",
             "--bins",
@@ -203,11 +206,10 @@ fn main() {
 
         cmd.env("CARGO_CFG_BPF_TARGET_ARCH", arch);
 
-        // Workaround to make sure that the rust-toolchain.toml is respected.
-        for key in ["RUSTUP_TOOLCHAIN", "RUSTC"] {
+        // Workaround to make sure that the correct toolchain is used.
+        for key in ["RUSTC", "RUSTC_WORKSPACE_WRAPPER"] {
             cmd.env_remove(key);
         }
-        cmd.current_dir(integration_ebpf_dir);
 
         // Workaround for https://github.com/rust-lang/cargo/issues/6412 where cargo flocks itself.
         let ebpf_target_dir = out_dir.join("integration-ebpf");

xtask/public-api/aya-ebpf.txt

@@ -469,7 +469,7 @@ impl aya_ebpf::maps::ring_buf::RingBuf
 pub fn aya_ebpf::maps::ring_buf::RingBuf::output<T: ?core::marker::Sized>(&self, data: &T, flags: u64) -> core::result::Result<(), i64>
 pub const fn aya_ebpf::maps::ring_buf::RingBuf::pinned(byte_size: u32, flags: u32) -> Self
 pub fn aya_ebpf::maps::ring_buf::RingBuf::query(&self, flags: u64) -> u64
-pub fn aya_ebpf::maps::ring_buf::RingBuf::reserve<T: 'static>(&self, flags: u64) -> core::option::Option<aya_ebpf::maps::ring_buf::RingBufEntry<T>> where const_assert::Assert<{ _ }>: const_assert::IsTrue
+pub fn aya_ebpf::maps::ring_buf::RingBuf::reserve<T: 'static>(&self, flags: u64) -> core::option::Option<aya_ebpf::maps::ring_buf::RingBufEntry<T>> where Assert<{ _ }>: IsTrue
 pub const fn aya_ebpf::maps::ring_buf::RingBuf::with_byte_size(byte_size: u32, flags: u32) -> Self
 impl core::marker::Sync for aya_ebpf::maps::ring_buf::RingBuf
 impl !core::marker::Freeze for aya_ebpf::maps::ring_buf::RingBuf
@@ -1195,7 +1195,7 @@ impl aya_ebpf::maps::ring_buf::RingBuf
 pub fn aya_ebpf::maps::ring_buf::RingBuf::output<T: ?core::marker::Sized>(&self, data: &T, flags: u64) -> core::result::Result<(), i64>
 pub const fn aya_ebpf::maps::ring_buf::RingBuf::pinned(byte_size: u32, flags: u32) -> Self
 pub fn aya_ebpf::maps::ring_buf::RingBuf::query(&self, flags: u64) -> u64
-pub fn aya_ebpf::maps::ring_buf::RingBuf::reserve<T: 'static>(&self, flags: u64) -> core::option::Option<aya_ebpf::maps::ring_buf::RingBufEntry<T>> where const_assert::Assert<{ _ }>: const_assert::IsTrue
+pub fn aya_ebpf::maps::ring_buf::RingBuf::reserve<T: 'static>(&self, flags: u64) -> core::option::Option<aya_ebpf::maps::ring_buf::RingBufEntry<T>> where Assert<{ _ }>: IsTrue
 pub const fn aya_ebpf::maps::ring_buf::RingBuf::with_byte_size(byte_size: u32, flags: u32) -> Self
 impl core::marker::Sync for aya_ebpf::maps::ring_buf::RingBuf
 impl !core::marker::Freeze for aya_ebpf::maps::ring_buf::RingBuf

xtask/src/run.rs

@@ -54,7 +54,7 @@ pub fn build<F>(target: Option<&str>, f: F) -> Result<Vec<(String, PathBuf)>>
 where
     F: FnOnce(&mut Command) -> &mut Command,
 {
-    // Always use rust-lld and -Zbuild-std in case we're cross-compiling.
+    // Always use rust-lld in case we're cross-compiling.
     let mut cmd = Command::new("cargo");
     cmd.args(["build", "--message-format=json"]);
     if let Some(target) = target {