perf_event: refactor perf_event_open_trace_point

Rewrite it in terms of perf_event_open.

aya/src/programs/probe.rs

@@ -9,8 +9,6 @@ use std::{
     sync::atomic::{AtomicUsize, Ordering},
 };
 
-use libc::pid_t;
-
 use crate::{
     programs::{
         Link, ProgramData, ProgramError, kprobe::KProbeError, perf_attach,
@@ -111,7 +109,7 @@ pub(crate) fn attach<T: Link + From<PerfLinkInner>>(
     // separate argument.
     fn_name: &OsStr,
     offset: u64,
-    pid: Option<pid_t>,
+    pid: Option<u32>,
     cookie: Option<u64>,
 ) -> Result<T::Id, ProgramError> {
     // https://github.com/torvalds/linux/commit/e12f03d7031a977356e3d7b75a68c2185ff8d155
@@ -153,7 +151,7 @@ fn create_as_probe(
     kind: ProbeKind,
     fn_name: &OsStr,
     offset: u64,
-    pid: Option<pid_t>,
+    pid: Option<u32>,
 ) -> Result<crate::MockableFd, ProgramError> {
     use ProbeKind::*;
 
@@ -188,7 +186,7 @@ fn create_as_trace_point(
     kind: ProbeKind,
     name: &OsStr,
     offset: u64,
-    pid: Option<pid_t>,
+    pid: Option<u32>,
 ) -> Result<(crate::MockableFd, OsString), ProgramError> {
     use ProbeKind::*;
 

aya/src/programs/trace_point.rs

@@ -115,7 +115,7 @@ pub(crate) fn read_sys_fs_trace_point_id(
     tracefs: &Path,
     category: &str,
     name: &Path,
-) -> Result<u32, TracePointError> {
+) -> Result<u64, TracePointError> {
     let filename = tracefs.join("events").join(category).join(name).join("id");
 
     let id = match fs::read_to_string(&filename) {

aya/src/programs/uprobe.rs

@@ -11,7 +11,6 @@ use std::{
 };
 
 use aya_obj::generated::{bpf_link_type, bpf_prog_type::BPF_PROG_TYPE_KPROBE};
-use libc::pid_t;
 use object::{Object as _, ObjectSection as _, ObjectSymbol as _, Symbol};
 use thiserror::Error;
 
@@ -109,7 +108,7 @@ impl UProbe {
         &mut self,
         location: Loc,
         target: T,
-        pid: Option<pid_t>,
+        pid: Option<u32>,
         cookie: Option<u64>,
     ) -> Result<UProbeLinkId, ProgramError> {
         let proc_map = pid.map(ProcMap::new).transpose()?;
@@ -159,9 +158,10 @@ where
         .and_then(|proc_map| {
             proc_map
                 .find_library_path_by_name(target)
-                .map_err(|source| UProbeError::ProcMap {
-                    pid: proc_map.pid,
-                    source,
+                .map_err(|source| {
+                    let ProcMap { pid, data: _ } = proc_map;
+                    let pid = *pid;
+                    UProbeError::ProcMap { pid, source }
                 })
                 .transpose()
         })
@@ -190,7 +190,7 @@ where
 )]
 fn test_resolve_attach_path() {
     // Look up the current process's pid.
-    let pid = std::process::id().try_into().unwrap();
+    let pid = std::process::id();
     let proc_map = ProcMap::new(pid).unwrap();
 
     // Now let's resolve the path to libc. It should exist in the current process's memory map and
@@ -287,7 +287,7 @@ pub enum UProbeError {
     #[error("error fetching libs for {pid}")]
     ProcMap {
         /// The pid.
-        pid: i32,
+        pid: u32,
         /// The [`ProcMapError`] that caused the error.
         #[source]
         source: ProcMapError,
@@ -419,12 +419,12 @@ impl<'a> ProcMapEntry<'a> {
 ///
 /// The information here may be used to resolve addresses to paths.
 struct ProcMap<T> {
-    pid: pid_t,
+    pid: u32,
     data: T,
 }
 
 impl ProcMap<Vec<u8>> {
-    fn new(pid: pid_t) -> Result<Self, UProbeError> {
+    fn new(pid: u32) -> Result<Self, UProbeError> {
         let filename = PathBuf::from(format!("/proc/{pid}/maps"));
         let data = fs::read(&filename)
             .map_err(|io_error| UProbeError::FileError { filename, io_error })?;

aya/src/sys/perf_event.rs

@@ -133,7 +133,7 @@ pub(crate) fn perf_event_open_probe(
     ret_bit: Option<u32>,
     name: &OsStr,
     offset: u64,
-    pid: Option<pid_t>,
+    pid: Option<u32>,
 ) -> io::Result<crate::MockableFd> {
     use std::os::unix::ffi::OsStrExt as _;
 
@@ -150,26 +150,30 @@ pub(crate) fn perf_event_open_probe(
     attr.__bindgen_anon_3.config1 = c_name.as_ptr() as u64;
     attr.__bindgen_anon_4.config2 = offset;
 
-    let cpu = if pid.is_some() { -1 } else { 0 };
-    let pid = pid.unwrap_or(-1);
+    let (pid, cpu) = match pid {
+        Some(pid) => (pid as i32, -1),
+        None => (-1, 0),
+    };
 
     perf_event_sys(attr, pid, cpu, PERF_FLAG_FD_CLOEXEC)
 }
 
 pub(crate) fn perf_event_open_trace_point(
-    id: u32,
-    pid: Option<pid_t>,
+    event_id: u64,
+    pid: Option<u32>,
 ) -> io::Result<crate::MockableFd> {
-    let mut attr = unsafe { mem::zeroed::<perf_event_attr>() };
-
-    attr.size = mem::size_of::<perf_event_attr>() as u32;
-    attr.type_ = PERF_TYPE_TRACEPOINT as u32;
-    attr.config = u64::from(id);
-
-    let cpu = if pid.is_some() { -1 } else { 0 };
-    let pid = pid.unwrap_or(-1);
-
-    perf_event_sys(attr, pid, cpu, PERF_FLAG_FD_CLOEXEC)
+    let scope = match pid {
+        Some(pid) => PerfEventScope::OneProcess { pid, cpu: None },
+        None => PerfEventScope::AllProcessesOneCpu { cpu: 0 },
+    };
+    perf_event_open(
+        PerfEventConfig::TracePoint { event_id },
+        scope,
+        SamplePolicy::Period(0),
+        WakeupPolicy::Events(1),
+        false,
+        PERF_FLAG_FD_CLOEXEC,
+    )
 }
 
 pub(crate) fn perf_event_ioctl(

xtask/public-api/aya.txt

@@ -7374,7 +7374,7 @@ pub aya::programs::uprobe::UProbeError::InvalidLdSoCache::io_error: &'static std
 pub aya::programs::uprobe::UProbeError::InvalidTarget
 pub aya::programs::uprobe::UProbeError::InvalidTarget::path: std::path::PathBuf
 pub aya::programs::uprobe::UProbeError::ProcMap
-pub aya::programs::uprobe::UProbeError::ProcMap::pid: i32
+pub aya::programs::uprobe::UProbeError::ProcMap::pid: u32
 pub aya::programs::uprobe::UProbeError::ProcMap::source: aya::programs::uprobe::ProcMapError
 pub aya::programs::uprobe::UProbeError::SymbolError
 pub aya::programs::uprobe::UProbeError::SymbolError::error: alloc::boxed::Box<(dyn core::error::Error + core::marker::Send + core::marker::Sync)>
@@ -7414,7 +7414,7 @@ pub fn aya::programs::uprobe::UProbeError::from(t: T) -> T
 pub struct aya::programs::uprobe::UProbe
 impl aya::programs::uprobe::UProbe
 pub const aya::programs::uprobe::UProbe::PROGRAM_TYPE: aya::programs::ProgramType
-pub fn aya::programs::uprobe::UProbe::attach<'loc, T: core::convert::AsRef<std::path::Path>, Loc: core::convert::Into<aya::programs::uprobe::UProbeAttachLocation<'loc>>>(&mut self, location: Loc, target: T, pid: core::option::Option<libc::unix::pid_t>, cookie: core::option::Option<u64>) -> core::result::Result<aya::programs::uprobe::UProbeLinkId, aya::programs::ProgramError>
+pub fn aya::programs::uprobe::UProbe::attach<'loc, T: core::convert::AsRef<std::path::Path>, Loc: core::convert::Into<aya::programs::uprobe::UProbeAttachLocation<'loc>>>(&mut self, location: Loc, target: T, pid: core::option::Option<u32>, cookie: core::option::Option<u64>) -> core::result::Result<aya::programs::uprobe::UProbeLinkId, aya::programs::ProgramError>
 pub fn aya::programs::uprobe::UProbe::from_pin<P: core::convert::AsRef<std::path::Path>>(path: P, kind: aya::programs::ProbeKind) -> core::result::Result<Self, aya::programs::ProgramError>
 pub fn aya::programs::uprobe::UProbe::kind(&self) -> aya::programs::ProbeKind
 pub fn aya::programs::uprobe::UProbe::load(&mut self) -> core::result::Result<(), aya::programs::ProgramError>
@@ -8627,7 +8627,7 @@ pub aya::programs::UProbeError::InvalidLdSoCache::io_error: &'static std::io::er
 pub aya::programs::UProbeError::InvalidTarget
 pub aya::programs::UProbeError::InvalidTarget::path: std::path::PathBuf
 pub aya::programs::UProbeError::ProcMap
-pub aya::programs::UProbeError::ProcMap::pid: i32
+pub aya::programs::UProbeError::ProcMap::pid: u32
 pub aya::programs::UProbeError::ProcMap::source: aya::programs::uprobe::ProcMapError
 pub aya::programs::UProbeError::SymbolError
 pub aya::programs::UProbeError::SymbolError::error: alloc::boxed::Box<(dyn core::error::Error + core::marker::Send + core::marker::Sync)>
@@ -10149,7 +10149,7 @@ pub fn aya::programs::trace_point::TracePoint::from(t: T) -> T
 pub struct aya::programs::UProbe
 impl aya::programs::uprobe::UProbe
 pub const aya::programs::uprobe::UProbe::PROGRAM_TYPE: aya::programs::ProgramType
-pub fn aya::programs::uprobe::UProbe::attach<'loc, T: core::convert::AsRef<std::path::Path>, Loc: core::convert::Into<aya::programs::uprobe::UProbeAttachLocation<'loc>>>(&mut self, location: Loc, target: T, pid: core::option::Option<libc::unix::pid_t>, cookie: core::option::Option<u64>) -> core::result::Result<aya::programs::uprobe::UProbeLinkId, aya::programs::ProgramError>
+pub fn aya::programs::uprobe::UProbe::attach<'loc, T: core::convert::AsRef<std::path::Path>, Loc: core::convert::Into<aya::programs::uprobe::UProbeAttachLocation<'loc>>>(&mut self, location: Loc, target: T, pid: core::option::Option<u32>, cookie: core::option::Option<u64>) -> core::result::Result<aya::programs::uprobe::UProbeLinkId, aya::programs::ProgramError>
 pub fn aya::programs::uprobe::UProbe::from_pin<P: core::convert::AsRef<std::path::Path>>(path: P, kind: aya::programs::ProbeKind) -> core::result::Result<Self, aya::programs::ProgramError>
 pub fn aya::programs::uprobe::UProbe::kind(&self) -> aya::programs::ProbeKind
 pub fn aya::programs::uprobe::UProbe::load(&mut self) -> core::result::Result<(), aya::programs::ProgramError>