The primary driver of change here is that `MapData::create` is now a
factory function that returns `Result<Self, _>` rather than mutating
`&mut self`. The remaining changes are consequences of that change, the
most notable of which is the removal of several errors which are no
longer possible.
- Add helper methods to get useful information from the ProgramInfo
object which is returned by the `loaded_programs()` API. Specifically
this code mirrors the `bpftool prog` command in terms of useful fields.
- Add a new API macro to each aya `Program` type to allow us to fetch
its accompanying `ProgramInfo` metadata after its been loaded.
- Add a new ProgramInfo constructor that builds a new instance using
a raw fd.
- Add a smoke test for the loaded_programs() API as well as
all the relevant methods on the ProgramInfo type.
Signed-off-by: Andrew Stoycos <astoycos@redhat.com>
Implements running integration tests on multiple VMs with arbitrary
kernel images using `cargo xtask integration-test vm ...`.
This changes our coverage from 6.2 to 6.1 and 6.4.
Some of these functions fail to compile when not inlined, so we should
be explicit.
Before deciding on this approach I tried various ways of making all
these functions #[inline(never)] to save instructions but I ran into
blockers:
- These functions currently return Result, which is a structure. This is
not permitted in BPF.
- I tried inventing a newtype that is a #[repr(transparent)] wrapper of
u16, and having these functions return that; however it seems that
even if the object code is legal, the verifier will reject such
functions because the BTF (if present, and it was in my local
experiments) would indicate that the return is a structure.
- I tried having these functions return a plain u16 where 0 means error,
but the verifier still rejected the BTF because the receiver (even if
made into &self) is considered a structure, and forbidden.
We can eventually overcome these problems by "lying" in our BTF once
support for it matures in the bpf-linker repo (e.g. Option<NonZeroU16>
should be perfectly legal as it is guaranteed to be word-sized), but we
aren't there yet, and this is the safest thing we can do for now.
The struct_flavors test previously expected the same thing with and
without relocations. It now expects different values.
Also rename an enum variant "u64" to "S64". This was a typo. Turns out
that U32 is a type that exists in kernel headers, so all enum values are
suffixed with "_VAL".
Remove stdlib.h and the call to exit(). This alone makes the test fail
with a poisoned relocation. Bringing over the map definition makes the
test work again.
This commit fixes the (func|line)_info when we have multiple programs in
the same section. The integration test reloc.bpf.c serves as our test
case here. This required filtering down the (func|line)_info to only
that in scope of the current symbol + then adjusting the offets to
appease the kernel.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
For unclear reasons, two of the integration tests related to uprobes
were resolving a symbol in libc. The integration-test binary can be
built statically, in which case it would not load or reference libc.
Statically linking the integration tests and running them in a VM
without a userland is a convenient mechanism to exercise the tests
against different kernel versions.
The fact that the statically linked integration-test binary does not
load libc is not the only reason these tests failed in such an
environment. In fact, the logic to look in the process's memory
maps was not running (because no pid was being passed).
Separate logic to determine which object file to use when attempting
to resolve a symbol for attaching a uprobe changes its behavior based
on whether that target is an absolute path. If the target is not an
absolute path, the code searches through the LdSoCache. This cache does
not always exist in linux systems; when an attach call is made with a
relative path target and there is no /etc/ld.so.cache file, the attach
call will fail. This commit does not change that behavior, it merely
sidesteps it.
Move the use of clang and llvm-objcopy from run-time to build-time. This
allows the integration tests to run on VMs with simpler userlands.
Create a new CI job to build the integration tests separately from
running them. Ship them from that job to the runner job using github
actions artifacts.
The aya-bpf-macros needed refactoring for:
1. Ease of testing
2. To be consistent with when we use K/V args vs. idents
3. To deprecate the use of `name` to change the exported name of a
function - we now use the symbol table.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
This makes a few changes to the way that Aya reads the ELF object
files.
1. To find programs in a section, we use the symbols table. This allows
for cases where multiple programs could appear in the same section.
2. When parsing our ELF file we build symbols_by_section_index as an
optimization as we use it for legacy maps, BTF maps and now programs.
As a result of theses changes the "NAME" used in `bpf.prog_mut("NAME")`
is now ALWAYS the same as the function name in the eBPF code, making the
user experience more consistent.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
For tests that do networking operations, this allows to have a
clean-state network namespace and interfaces for each test. Mainly, this
avoids "device or resource busy" errors when reusing the loopback
interface across tests.
In release, the trigger functions were being optimized out and the
tests did not work. Use core::hint::black_box to ensure that the
functions are not optimized out. Also, run these integration tests
in CI to ensure that we don't regress.
Trampoline cargo-in-cargo stdio through cargo:warning to ensure the user
sees all the output.
Use bpf-linker from git in CI so we can see what's going on there.
Remove the manual dependency tracking machinery in
integration-test/build.rs in favor of a build-dependency on
integration-ebpf. This required adding an empty lib.rs to create the
library target.
This allows integration-test/build.rs to be ignorant of bpf-linker.
Remove that in favor of the logic now in integration-ebpf.
Extract the symlink-to-bpf-linker logic from integration-test to xtask
and use it in a new build script in integration-ebpf, causing ebpf
probes to be rebuilt when bpf-linker changes. Previously bpf-linker
changes would rebuild integration-test, but not integration-ebpf,
resulting in stale tests.
Note that this still doesn't address the possibility that a new
bpf-linker is added to the PATH ahead of the cached one. Solving this in
the general case would require rebuild-if-changed-env=PATH *and*
rebuild-if-changed={every-directory-in-PATH} which would likely mean far
too much cache invalidation.
The ebpf probes require a nightly compiler. Before this change, if you
ran `cargo xtask integration-test` with a stable compiler toolchain as
default, or you ran `cargo +stable xtask integration-test`, you would
have seen an error like the one below. This is now fixed by running the
cargo build command in the integration-ebpf directory and making sure
to clear the RUSTUP_TOOLCHAIN env var.
```
--- stderr
/home/ajwerner/src/github.com/aya-rs/aya/test/integration-test/bpf/ring_buf_sched_tracepoint.bpf.c:18:21: warning: declaration of 'struct switch_args' will not be visible outside of this function [-Wvisibility]
int bpf_prog(struct switch_args* ctx)
^
1 warning generated.
error: the `-Z` flag is only accepted on the nightly channel of Cargo, but this is the `stable` channel
See https://doc.rust-lang.org/book/appendix-07-nightly-rust.html for more information about Rust release channels.
thread 'main' panicked at '"cargo" "build" "-p" "integration-ebpf" "-Z" "build-std=core" "--release" "--message-format=json" "--target" "bpfel-unknown-none" "--target-dir" "/home/ajwerner/src/github.com/aya-rs/aya/target/debug/build/integration-test-9bbcb3db5e9f8f57/out/integration-ebpf" exited
with status code 101:
', test/integration-test/build.rs:219:25
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
Error: error while building userspace application
Caused by:
Child { stdin: None, stdout: None, stderr: None, .. } exited with status code 101:
```
Libbpf is used by xtasks, in the command, ensure that the submodules
are initialized. This eases the user-experience so that users don't
need to think about the submodule, while retaining all the benefits
of using a submodule vs forcing the user to manually check out libbpf
and stick it in some pre-defined place.
We use the symbol pointing to libbpf in xtask in the build script
to avoid repeating this constant.
Also, we install git in the vm so that we can init the submodule
when we build in the vm.
Emit "cargo:rerun-if-changed={}" for each transitive dependency on
integration-ebpf. In a normal world we'd just add integration-ebpf to
our build-dependencies, but cargo ignores this because integration-ebpf
has no library targets.
The matches crate has been archived now that `matches!` is in std.
However `assert_matches!` is still unstable in std, and the
assert_matches crate provides a more expressive form:
```
assert_matches!(foo, Ok(bar) => {
assert_eq!(bar, baz);
});
```
This feature is equivalent to async_tokio || async_std; removing it
avoids warnings emitted during `cargo hack check --feature-powerset`
where async is selected without either of the other features.
Use cargo hack to ensure clippy runs on the powerset of features.
in the integration tests we recenctly switched to using
our internal api to list programs. I was seeing times when
this would race and panic internally (program fd was deleted
by aya WHILE we were trying to get it). This ensures that
the list succeeded without panicking.
Signed-off-by: Andrew Stoycos <astoycos@redhat.com>
Add integration testing for link pinning and
loading/unloading of tracepoint, kprobe, and
uprobe programs.
Redo how we utilize bpftool to verify that programs
are loaded to be explicit with names. Also add a helper
to verify that a program is loaded AND linked.
Signed-off-by: Andrew Stoycos <astoycos@redhat.com>
We need bpftool to add tests for the link APIs since we don't yet have
and aya API for listing links.
Signed-off-by: Andrew Stoycos <astoycos@redhat.com>
"integration tests" as defined by Cargo produce a binary per file in the
tests directory. This is really not what we want and has a number of
downsides, but the main one is binary size.
Before:
tamird@pc:~/src/aya$ cargo xtask build-integration-test | xargs ls -lah
Finished dev [unoptimized + debuginfo] target(s) in 0.05s
Running `target/debug/xtask build-integration-test`
Compiling integration-test v0.1.0 (/home/tamird/src/aya/test/integration-test)
Finished dev [unoptimized + debuginfo] target(s) in 0.68s
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/bpf_probe_read-e03eb905a5e6209c
-rwxrwxr-x 1 tamird tamird 35M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/btf_relocations-57a4fbb38bf06064
-rwxrwxr-x 1 tamird tamird 31M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/elf-98b7a32d6d04effb
-rwxrwxr-x 1 tamird tamird 6.9M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/integration_test-0dd55ce96bfdad77
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/load-0718562e85b86d03
-rwxrwxr-x 1 tamird tamird 40M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/log-dbf355f9ea34068a
-rwxrwxr-x 1 tamird tamird 36M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/rbpf-89a1bb848fa5cc3c
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/relocations-cfe655c3bb413d8b
-rwxrwxr-x 1 tamird tamird 34M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/smoke-ccd3974180a3fd29
After:
tamird@pc:~/src/aya$ cargo xtask build-integration-test | xargs ls -lah
Finished dev [unoptimized + debuginfo] target(s) in 0.05s
Running `target/debug/xtask build-integration-test`
Compiling integration-test v0.1.0 (/home/tamird/src/aya/test/integration-test)
Finished dev [unoptimized + debuginfo] target(s) in 0.90s
-rwxrwxr-x 1 tamird tamird 47M Jul 12 15:21 /home/tamird/src/aya/target/debug/deps/integration_test-0dd55ce96bfdad77
Since we plan to run these tests in a VM, copying 10x fewer bytes seems
like a win.
Use the environment variable AYA_BUILD_INTEGRATION_BPF to indicate to
the build script that it should *actually* build bpf, otherwise emitting
empty files.
This allows metadata builds to skip costly build steps without
sacrificing ergonomics; all compile-time tools such as cargo clippy work
out of the box.
Cargo even gives each of these builds (depending on the value of the
environment variable) its own cache key, so they do not invalidate each
other when the user alternates between metadata and real builds.
This allows the lint action to move out of the VM.
- Add libbpf as a submodule. This prevents having to plumb its location
around (which can't be passed to Cargo build scripts) and also
controls the version against which codegen has run.
- Move bpf written in C to the integration-test crate and define
constants for each probe.
- Remove magic; each C source file must be directly enumerated in the
build script and in lib.rs.
Replace all `assert!(matches!(..))` with `assert_matches!(..)`.
Remove the now-unused build-integration-test xtask command whose logic
doesn't match that of the build-and-run command.
This doesn't add any value; use `cargo build --tests` with
`--message-format=json` instead; parse the output using `cargo_metadata`
to discover the location of the test binary.
Move test/integration-test/src/tests -> test/integration-test/tests to
conform to
https://doc.rust-lang.org/book/ch11-03-test-organization.html#integration-tests.
This change does a few things:
- it fixes a bug in the wrappers, where we were expecting the kernel to
return len=1 for b"\0" where it instead returns 0 and doesn't write
out the NULL terminator
- it makes the helpers more robust by hardcoding bound checks in
assembly so that LLVM optimizations can't transform the checks in a
way that the verifier can't understand.
- it adds integration tests
Before this change:
```
error[E0382]: use of moved value: `no_copy`
--> test/integration-ebpf/src/log.rs:35:9
|
33 | let no_copy = NoCopy {};
| ------- move occurs because `no_copy` has type `NoCopy`, which does not implement the `Copy` trait
34 |
35 | debug!(&ctx, "{:x}", no_copy.consume());
| ^^^^^^^^^^^^^^^^^^^^^-------^---------^
| | | |
| | | `no_copy` moved due to this method call
| | use occurs due to use in closure
| value used here after move
|
note: `NoCopy::consume` takes ownership of the receiver `self`, which moves `no_copy`
--> test/integration-ebpf/src/log.rs:28:24
|
28 | fn consume(self) -> u64 {
| ^^^^
= note: this error originates in the macro `debug` (in Nightly builds, run with -Z macro-backtrace for more info)
For more information about this error, try `rustc --explain E0382`.
error: could not compile `integration-ebpf` (bin "log") due to previous error
```
This fix aya wrong logic causing non entrypoint functions to not have
any BTF relocations working.
Also fix missing section_offset computation for instruction offset in
multiple spots.
Having separate format hints and tokens per IP address family is
unnecessary, since they are represented by different types and we handle
format hints for each type separately. So we can just have one format
hint.
Also, we should be consistent with the format strings grammar in
Rust[0]. The `type` token, which is mapped to formatting traits, usually
consists of one letter[1] (and optional `?` for `Debug` trait, but that
doesn't matter for us). It shouldn't consist of multiple letters. Our
`:ipv4` and `:ipv6` tokens were clearly breaking that convention, so we
should rather switch to something with one letter - hence `:i`.
[0] https://doc.rust-lang.org/std/fmt/#syntax
[1] https://doc.rust-lang.org/std/fmt/#formatting-traits
Now that bpf-linker uses llvm 16, the easiest way is to use Fedora 38
Beta with the testing repos as they have it, without resorting to
Rawhide.
See https://packages.fedoraproject.org/pkgs/llvm/llvm/.
This commit adds from_pin() which allows the creation of a Program
from a path on bpffs. This is useful to be able to call `attach` or
other APIs for programs that are already loaded to the kernel.
This differs from #444 since it implements this on the concrete program
type, not the Program enum, allowing the user to pass in any additional
context that isn't available from bpf_prog_info.
Signed-off-by: Dave Tucker <dave@dtucker.co.uk>
Tamir Duberstein
Andrew Stoycos
Dave Tucker
Andrew Werner
Tuetuopay
vadorovsky
Alessandro Decina
dependabot[bot]
Mary
Michal Rostecki