From 48fdf5a250ce74516a02c0f34b0f359f7f9a4d63 Mon Sep 17 00:00:00 2001
From: banditopazzo <banditopazzo@gmail.com>
Date: Tue, 10 Jan 2023 10:57:52 +0100
Subject: [PATCH] chore: tracefs review fixes

---
 aya/src/programs/mod.rs         |  6 +++---
 aya/src/programs/probe.rs       |  8 ++++----
 aya/src/programs/trace_point.rs |  5 ++---
 aya/src/programs/utils.rs       | 15 ++++++++-------
 4 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/aya/src/programs/mod.rs b/aya/src/programs/mod.rs
index 828de7ba..4454fcc3 100644
--- a/aya/src/programs/mod.rs
+++ b/aya/src/programs/mod.rs
@@ -207,9 +207,9 @@ pub enum ProgramError {
         name: String,
     },
 
-    /// TraceFS not found.
-    #[error("tracefs non found")]
-    TraceFsNotFound,
+    /// An error occurred while working with IO.
+    #[error(transparent)]
+    IOError(#[from] io::Error),
 }
 
 /// A [`Program`] file descriptor.
diff --git a/aya/src/programs/probe.rs b/aya/src/programs/probe.rs
index f5b0f939..f595ca53 100644
--- a/aya/src/programs/probe.rs
+++ b/aya/src/programs/probe.rs
@@ -9,8 +9,8 @@ use std::{
 use crate::{
     programs::{
         kprobe::KProbeError, perf_attach, perf_attach::PerfLink, perf_attach_debugfs,
-        trace_point::read_sys_fs_trace_point_id, uprobe::UProbeError, utils::get_tracefs, Link,
-        ProgramData, ProgramError,
+        trace_point::read_sys_fs_trace_point_id, uprobe::UProbeError, utils::find_tracefs_path,
+        Link, ProgramData, ProgramError,
     },
     sys::{kernel_version, perf_event_open_probe, perf_event_open_trace_point},
 };
@@ -61,7 +61,7 @@ pub(crate) fn attach<T: Link + From<PerfLink>>(
 pub(crate) fn detach_debug_fs(kind: ProbeKind, event_alias: &str) -> Result<(), ProgramError> {
     use ProbeKind::*;
 
-    let tracefs = get_tracefs()?;
+    let tracefs = find_tracefs_path()?;
 
     match kind {
         KProbe | KRetProbe => delete_probe_event(tracefs, kind, event_alias)
@@ -118,7 +118,7 @@ fn create_as_trace_point(
 ) -> Result<(i32, String), ProgramError> {
     use ProbeKind::*;
 
-    let tracefs = get_tracefs()?;
+    let tracefs = find_tracefs_path()?;
 
     let event_alias = match kind {
         KProbe | KRetProbe => create_probe_event(tracefs, kind, name, offset)
diff --git a/aya/src/programs/trace_point.rs b/aya/src/programs/trace_point.rs
index a5f25e1d..d4bf158d 100644
--- a/aya/src/programs/trace_point.rs
+++ b/aya/src/programs/trace_point.rs
@@ -7,13 +7,12 @@ use crate::{
     programs::{
         define_link_wrapper, load_program,
         perf_attach::{perf_attach, PerfLink, PerfLinkId},
+        utils::find_tracefs_path,
         ProgramData, ProgramError,
     },
     sys::perf_event_open_trace_point,
 };
 
-use super::utils::get_tracefs;
-
 /// The type returned when attaching a [`TracePoint`] fails.
 #[derive(Debug, Error)]
 pub enum TracePointError {
@@ -79,7 +78,7 @@ impl TracePoint {
     ///
     /// The returned value can be used to detach, see [TracePoint::detach].
     pub fn attach(&mut self, category: &str, name: &str) -> Result<TracePointLinkId, ProgramError> {
-        let tracefs = get_tracefs()?;
+        let tracefs = find_tracefs_path()?;
         let id = read_sys_fs_trace_point_id(tracefs, category, name)?;
         let fd = perf_event_open_trace_point(id, None).map_err(|(_code, io_error)| {
             ProgramError::SyscallError {
diff --git a/aya/src/programs/utils.rs b/aya/src/programs/utils.rs
index e9c431b0..143e8664 100644
--- a/aya/src/programs/utils.rs
+++ b/aya/src/programs/utils.rs
@@ -1,5 +1,5 @@
 //! Common functions shared between multiple eBPF program types.
-use std::{ffi::CStr, os::unix::io::RawFd, path::Path};
+use std::{ffi::CStr, io, os::unix::io::RawFd, path::Path};
 
 use crate::{
     programs::{FdLink, Link, ProgramData, ProgramError},
@@ -23,24 +23,25 @@ pub(crate) fn attach_raw_tracepoint<T: Link + From<FdLink>>(
     program_data.links.insert(FdLink::new(pfd).into())
 }
 
-// Get tracefs filesystem 
-pub(crate) fn get_tracefs() -> Result<&'static Path, ProgramError> {
+/// Find tracefs filesystem path
+pub(crate) fn find_tracefs_path() -> Result<&'static Path, ProgramError> {
     lazy_static::lazy_static! {
         static ref TRACE_FS: Option<&'static Path> = {
-            let mounts = [
+            let known_mounts = [
                 Path::new("/sys/kernel/tracing"),
                 Path::new("/sys/kernel/debug/tracing"),
             ];
 
-            for mount in mounts {
+            for mount in known_mounts {
                 if mount.exists() {
                     return Some(mount);
                 }
             }
             None
-
         };
     }
 
-    TRACE_FS.as_deref().ok_or(ProgramError::TraceFsNotFound)
+    TRACE_FS
+        .as_deref()
+        .ok_or_else(|| io::Error::new(io::ErrorKind::Other, "tracefs not found").into())
 }