programs: avoid assumptions that paths are UTF-8

aya/src/programs/kprobe.rs

@@ -68,7 +68,7 @@ impl KProbe {
     ///
     /// The returned value can be used to detach from the given function, see [KProbe::detach].
     pub fn attach(&mut self, fn_name: &str, offset: u64) -> Result<KProbeLinkId, ProgramError> {
-        attach(&mut self.data, self.kind, fn_name, offset, None)
+        attach(&mut self.data, self.kind, Path::new(fn_name), offset, None)
     }
 
     /// Detaches the program.

aya/src/programs/probe.rs

@@ -51,14 +51,15 @@ pub(crate) struct ProbeEvent {
 pub(crate) fn attach<T: Link + From<PerfLinkInner>>(
     program_data: &mut ProgramData<T>,
     kind: ProbeKind,
-    fn_name: &str,
+    name: &Path,
     offset: u64,
     pid: Option<pid_t>,
 ) -> Result<T::Id, ProgramError> {
     // https://github.com/torvalds/linux/commit/e12f03d7031a977356e3d7b75a68c2185ff8d155
     // Use debugfs to create probe
     if KernelVersion::current().unwrap() < KernelVersion::new(4, 17, 0) {
-        let (fd, event_alias) = create_as_trace_point(kind, fn_name, offset, pid)?;
+        let (fd, event_alias) =
+            create_as_trace_point(kind, name.to_string_lossy().as_ref(), offset, pid)?;
         let link = T::from(perf_attach_debugfs(
             program_data.fd_or_err()?,
             fd,
@@ -67,7 +68,7 @@ pub(crate) fn attach<T: Link + From<PerfLinkInner>>(
         return program_data.links.insert(link);
     };
 
-    let fd = create_as_probe(kind, fn_name, offset, pid)?;
+    let fd = create_as_probe(kind, name, offset, pid)?;
     let link = T::from(perf_attach(program_data.fd_or_err()?, fd)?);
     program_data.links.insert(link)
 }
@@ -92,7 +93,7 @@ pub(crate) fn detach_debug_fs(event: ProbeEvent) -> Result<(), ProgramError> {
 
 fn create_as_probe(
     kind: ProbeKind,
-    fn_name: &str,
+    name: &Path,
     offset: u64,
     pid: Option<pid_t>,
 ) -> Result<OwnedFd, ProgramError> {
@@ -117,7 +118,7 @@ fn create_as_probe(
         _ => None,
     };
 
-    perf_event_open_probe(perf_ty, ret_bit, fn_name, offset, pid).map_err(|(_code, io_error)| {
+    perf_event_open_probe(perf_ty, ret_bit, name, offset, pid).map_err(|(_code, io_error)| {
         SyscallError {
             call: "perf_event_open",
             io_error,

aya/src/programs/uprobe.rs

@@ -4,7 +4,7 @@ use object::{Object, ObjectSection, ObjectSymbol};
 use std::{
     borrow::Cow,
     error::Error,
-    ffi::CStr,
+    ffi::{CStr, OsStr, OsString},
     fs,
     io::{self, BufRead, Cursor, Read},
     mem,
@@ -49,6 +49,39 @@ pub struct UProbe {
     pub(crate) kind: ProbeKind,
 }
 
+trait OsStringExt {
+    fn starts_with(&self, needle: &OsStr) -> bool;
+    fn ends_with(&self, needle: &OsStr) -> bool;
+    fn strip_prefix(&self, prefix: &OsStr) -> Option<&OsStr>;
+    fn strip_suffix(&self, suffix: &OsStr) -> Option<&OsStr>;
+}
+
+impl OsStringExt for OsStr {
+    fn starts_with(&self, needle: &OsStr) -> bool {
+        use std::os::unix::ffi::OsStrExt as _;
+        self.as_bytes().starts_with(needle.as_bytes())
+    }
+
+    fn ends_with(&self, needle: &OsStr) -> bool {
+        use std::os::unix::ffi::OsStrExt as _;
+        self.as_bytes().ends_with(needle.as_bytes())
+    }
+
+    fn strip_prefix(&self, prefix: &OsStr) -> Option<&OsStr> {
+        use std::os::unix::ffi::OsStrExt as _;
+        self.as_bytes()
+            .strip_prefix(prefix.as_bytes())
+            .map(OsStr::from_bytes)
+    }
+
+    fn strip_suffix(&self, suffix: &OsStr) -> Option<&OsStr> {
+        use std::os::unix::ffi::OsStrExt as _;
+        self.as_bytes()
+            .strip_suffix(suffix.as_bytes())
+            .map(OsStr::from_bytes)
+    }
+}
+
 impl UProbe {
     /// Loads the program inside the kernel.
     pub fn load(&mut self) -> Result<(), ProgramError> {
@@ -127,31 +160,30 @@ impl UProbe {
 fn resolve_attach_path<T: AsRef<Path>>(
     target: &T,
     pid: Option<pid_t>,
-) -> Result<Cow<'_, str>, UProbeError> {
+) -> Result<Cow<'_, Path>, UProbeError> {
     // Look up the path for the target. If it there is a pid, and the target is a library name
     // that is in the process's memory map, use the path of that library. Otherwise, use the target as-is.
     let target = target.as_ref();
     let invalid_target = || UProbeError::InvalidTarget {
         path: target.to_owned(),
     };
-    let target_str = target.to_str().ok_or_else(invalid_target)?;
     pid.and_then(|pid| {
-        find_lib_in_proc_maps(pid, target_str)
+        find_lib_in_proc_maps(pid, target)
             .map_err(|io_error| UProbeError::FileError {
                 filename: format!("/proc/{pid}/maps"),
                 io_error,
             })
             .map(|v| v.map(Cow::Owned))
             .transpose()
     })
-    .or_else(|| target.is_absolute().then(|| Ok(Cow::Borrowed(target_str))))
+    .or_else(|| target.is_absolute().then(|| Ok(Cow::Borrowed(target))))
     .or_else(|| {
         LD_SO_CACHE
             .as_ref()
             .map_err(|error| UProbeError::InvalidLdSoCache {
                 io_error: error.clone(),
             })
-            .map(|cache| cache.resolve(target_str).map(Cow::Borrowed))
+            .map(|cache| cache.resolve(target).map(Cow::Borrowed))
             .transpose()
     })
     .unwrap_or_else(|| Err(invalid_target()))
@@ -172,6 +204,7 @@ fn test_resolve_attach_path() {
     // Now let's resolve the path to libc. It should exist in the current process's memory map and
     // then in the ld.so.cache.
     let libc_path = resolve_attach_path(&"libc", Some(pid)).unwrap();
+    let libc_path = libc_path.to_str().unwrap();
 
     // Make sure we got a path that contains libc.
     assert!(libc_path.contains("libc"), "libc_path: {}", libc_path);
@@ -249,45 +282,55 @@ pub enum UProbeError {
     },
 }
 
-fn proc_maps_libs(pid: pid_t) -> Result<Vec<(String, String)>, io::Error> {
+fn proc_maps_libs(pid: pid_t) -> Result<Vec<(OsString, PathBuf)>, io::Error> {
+    use std::os::unix::ffi::OsStrExt as _;
+
     let maps_file = format!("/proc/{pid}/maps");
-    let data = fs::read_to_string(maps_file)?;
-
-    Ok(data
-        .lines()
-        .filter_map(|line| {
-            let line = line.split_whitespace().last()?;
-            if line.starts_with('/') {
-                let path = PathBuf::from(line);
-                let key = path.file_name().unwrap().to_string_lossy().into_owned();
-                Some((key, path.to_string_lossy().to_string()))
-            } else {
-                None
+    let data = fs::read(maps_file)?;
+
+    let libs = data
+        .split(|b| b == &b'\n')
+        .filter_map(|mut line| {
+            loop {
+                if let [stripped @ .., c] = line {
+                    if c.is_ascii_whitespace() {
+                        line = stripped;
+                        continue;
+                    }
+                }
+                break;
             }
+            let path = line.split(|b| b.is_ascii_whitespace()).last()?;
+            let path = Path::new(OsStr::from_bytes(path));
+            path.is_absolute()
+                .then(|| {
+                    path.file_name()
+                        .map(|file_name| (file_name.to_owned(), path.to_owned()))
+                })
+                .flatten()
         })
-        .collect())
+        .collect();
+    Ok(libs)
 }
 
-fn find_lib_in_proc_maps(pid: pid_t, lib: &str) -> Result<Option<String>, io::Error> {
+fn find_lib_in_proc_maps(pid: pid_t, lib: &Path) -> Result<Option<PathBuf>, io::Error> {
     let libs = proc_maps_libs(pid)?;
 
-    let ret = if lib.contains(".so") {
-        libs.into_iter().find(|(k, _)| k.as_str().starts_with(lib))
-    } else {
-        libs.into_iter().find(|(k, _)| {
-            k.strip_prefix(lib)
-                .map(|k| k.starts_with(".so") || k.starts_with('-'))
-                .unwrap_or_default()
-        })
-    };
+    let lib = lib.as_os_str();
+    let lib = lib.strip_suffix(OsStr::new(".so")).unwrap_or(lib);
 
-    Ok(ret.map(|(_, v)| v))
+    Ok(libs.into_iter().find_map(|(file_name, path)| {
+        file_name.strip_prefix(lib).and_then(|suffix| {
+            (suffix.starts_with(OsStr::new(".so")) || suffix.starts_with(OsStr::new("-")))
+                .then_some(path)
+        })
+    }))
 }
 
 #[derive(Debug)]
 pub(crate) struct CacheEntry {
-    key: String,
-    value: String,
+    key: OsString,
+    value: OsString,
     _flags: i32,
 }
 
@@ -368,11 +411,16 @@ impl LdSoCache {
                 }
 
                 let read_str = |pos| {
-                    unsafe {
-                        CStr::from_ptr(cursor.get_ref()[offset + pos..].as_ptr() as *const c_char)
-                    }
-                    .to_string_lossy()
-                    .into_owned()
+                    use std::os::unix::ffi::OsStrExt as _;
+                    OsStr::from_bytes(
+                        unsafe {
+                            CStr::from_ptr(
+                                cursor.get_ref()[offset + pos..].as_ptr() as *const c_char
+                            )
+                        }
+                        .to_bytes(),
+                    )
+                    .to_owned()
                 };
 
                 let key = read_str(k_pos);
@@ -389,16 +437,18 @@ impl LdSoCache {
         Ok(LdSoCache { entries })
     }
 
-    pub fn resolve(&self, lib: &str) -> Option<&str> {
-        let lib = if !lib.contains(".so") {
-            lib.to_string() + ".so"
-        } else {
-            lib.to_string()
-        };
+    pub fn resolve(&self, lib: &Path) -> Option<&Path> {
+        let lib = lib.as_os_str();
+        let lib = lib.strip_suffix(OsStr::new(".so")).unwrap_or(lib);
         self.entries
             .iter()
-            .find(|entry| entry.key.starts_with(&lib))
-            .map(|entry| entry.value.as_str())
+            .find_map(|CacheEntry { key, value, _flags }| {
+                key.strip_prefix(lib).and_then(|suffix| {
+                    suffix
+                        .starts_with(OsStr::new(".so"))
+                        .then_some(Path::new(value.as_os_str()))
+                })
+            })
     }
 }
 
@@ -420,7 +470,7 @@ enum ResolveSymbolError {
     SectionFileRangeNone(String, Result<String, object::Error>),
 }
 
-fn resolve_symbol(path: &str, symbol: &str) -> Result<u64, ResolveSymbolError> {
+fn resolve_symbol(path: &Path, symbol: &str) -> Result<u64, ResolveSymbolError> {
     let data = fs::read(path)?;
     let obj = object::read::File::parse(&*data)?;
 

aya/src/sys/perf_event.rs

@@ -2,6 +2,7 @@ use std::{
     ffi::{c_long, CString},
     io, mem,
     os::fd::{BorrowedFd, FromRawFd as _, OwnedFd},
+    path::Path,
 };
 
 use libc::{c_int, pid_t};
@@ -62,17 +63,19 @@ pub(crate) fn perf_event_open_bpf(cpu: c_int) -> SysResult<OwnedFd> {
 pub(crate) fn perf_event_open_probe(
     ty: u32,
     ret_bit: Option<u32>,
-    name: &str,
+    name: &Path,
     offset: u64,
     pid: Option<pid_t>,
 ) -> SysResult<OwnedFd> {
+    use std::os::unix::ffi::OsStrExt as _;
+
     let mut attr = unsafe { mem::zeroed::<perf_event_attr>() };
 
     if let Some(ret_bit) = ret_bit {
         attr.config = 1 << ret_bit;
     }
 
-    let c_name = CString::new(name).unwrap();
+    let c_name = CString::new(name.as_os_str().as_bytes()).unwrap();
 
     attr.size = mem::size_of::<perf_event_attr>() as u32;
     attr.type_ = ty;