From 9b21c85a6ff16c24bce096ff0814cc313725c509 Mon Sep 17 00:00:00 2001
From: aorhant <aorhant@scaleway.com>
Date: Wed, 26 Feb 2025 18:54:13 +0100
Subject: [PATCH] feat(aya): return correct Option from
bpf_map_lookup_elem_per_cpu
bpf_map_lookup_elem_per_cpu doesn't check the Option inside the Result:Ok,
thus when it receive a Ok(None), it returns a zeroed value PerCpuValues.
---
aya/src/maps/hash_map/per_cpu_hash_map.rs | 25 ++++++++++++++++++++++-
aya/src/sys/bpf.rs | 2 +-
2 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/aya/src/maps/hash_map/per_cpu_hash_map.rs b/aya/src/maps/hash_map/per_cpu_hash_map.rs
index d9194668..3d402a8b 100644
--- a/aya/src/maps/hash_map/per_cpu_hash_map.rs
+++ b/aya/src/maps/hash_map/per_cpu_hash_map.rs
@@ -151,12 +151,23 @@ impl<T: Borrow<MapData>, K: Pod, V: Pod> IterableMap<K, PerCpuValues<V>>
#[cfg(test)]
mod tests {
+ use std::{ffi::c_long, io};
+
+ use assert_matches::assert_matches;
use aya_obj::generated::bpf_map_type::{
BPF_MAP_TYPE_LRU_PERCPU_HASH, BPF_MAP_TYPE_PERCPU_HASH,
};
+ use libc::ENOENT;
use super::*;
- use crate::maps::{test_utils, Map};
+ use crate::{
+ maps::{test_utils, Map},
+ sys::{override_syscall, SysResult},
+ };
+
+ fn sys_error(value: i32) -> SysResult<c_long> {
+ Err((-1, io::Error::from_raw_os_error(value)))
+ }
#[test]
fn test_try_from_ok() {
@@ -174,4 +185,16 @@ mod tests {
let map = Map::PerCpuLruHashMap(map_data());
assert!(PerCpuHashMap::<_, u32, u32>::try_from(&map).is_ok())
}
+ #[test]
+ #[cfg_attr(miri, ignore = "`open` not available when isolation is enabled")]
+ fn test_get_not_found() {
+ let map_data =
+ || test_utils::new_map(test_utils::new_obj_map::<u32>(BPF_MAP_TYPE_LRU_PERCPU_HASH));
+ let map = Map::PerCpuHashMap(map_data());
+ let map = PerCpuHashMap::<_, u32, u32>::try_from(&map).unwrap();
+
+ override_syscall(|_| sys_error(ENOENT));
+
+ assert_matches!(map.get(&1, 0), Err(MapError::KeyNotFound));
+ }
}
diff --git a/aya/src/sys/bpf.rs b/aya/src/sys/bpf.rs
index 791959f1..51ca7a97 100644
--- a/aya/src/sys/bpf.rs
+++ b/aya/src/sys/bpf.rs
@@ -249,7 +249,7 @@ pub(crate) fn bpf_map_lookup_elem_per_cpu<K: Pod, V: Pod>(
) -> SysResult<Option<PerCpuValues<V>>> {
let mut mem = PerCpuValues::<V>::alloc_kernel_mem().map_err(|io_error| (-1, io_error))?;
match bpf_map_lookup_elem_ptr(fd, Some(key), mem.as_mut_ptr(), flags) {
- Ok(_) => Ok(Some(unsafe { PerCpuValues::from_kernel_mem(mem) })),
+ Ok(v) => Ok(v.map(|()| unsafe { PerCpuValues::from_kernel_mem(mem) })),
Err((_, io_error)) if io_error.raw_os_error() == Some(ENOENT) => Ok(None),
Err(e) => Err(e),
}