aya: uprobe attach: use mmap instead of reading whole binaries to memory

aya/src/programs/uprobe.rs

@@ -24,6 +24,7 @@ use crate::{
         probe::{OsStringExt as _, ProbeKind, attach},
     },
     sys::bpf_link_get_info_by_fd,
+    util::mmap::MMap,
 };
 
 const LD_SO_CACHE_FILE: &str = "/etc/ld.so.cache";
@@ -712,15 +713,15 @@ fn symbol_translated_address(
 }
 
 fn resolve_symbol(path: &Path, symbol: &str) -> Result<u64, ResolveSymbolError> {
-    let data = fs::read(path)?;
-    let obj = object::read::File::parse(&*data)?;
+    let data = MMap::mmap_whole_file(path)?;
+    let obj = object::read::File::parse(data.as_ref())?;
 
     if let Some(sym) = find_symbol_in_object(&obj, symbol) {
         symbol_translated_address(&obj, sym, symbol)
     } else {
         // Only search in the debug object if the symbol was not found in the main object
         let debug_path = find_debug_path_in_object(&obj, path, symbol)?;
-        let debug_data = fs::read(&debug_path).map_err(|e| {
+        let debug_data = MMap::mmap_whole_file(&debug_path).map_err(|e| {
             ResolveSymbolError::DebuglinkAccessError(
                 debug_path
                     .to_str()
@@ -729,7 +730,7 @@ fn resolve_symbol(path: &Path, symbol: &str) -> Result<u64, ResolveSymbolError>
                 e,
             )
         })?;
-        let debug_obj = object::read::File::parse(&*debug_data)?;
+        let debug_obj = object::read::File::parse(debug_data.as_ref())?;
 
         verify_build_ids(&obj, &debug_obj, symbol)?;
 

aya/src/util/mmap.rs

@@ -1,7 +1,12 @@
 //! Safe wrapper around memory-mapped files.
 
-use libc::{MAP_FAILED, c_int, c_void, off_t};
-use std::{io, os::fd::BorrowedFd, ptr};
+use libc::{MAP_FAILED, MAP_PRIVATE, PROT_READ, c_int, c_void, off_t};
+use std::{
+    fs, io,
+    os::fd::{AsFd, BorrowedFd},
+    path::Path,
+    ptr,
+};
 
 use crate::sys::{SyscallError, mmap, munmap};
 
@@ -45,6 +50,19 @@ impl MMap {
             }
         }
     }
+
+    /// Maps the file at `path` for reading, using `mmap` with `MAP_PRIVATE`.
+    pub(crate) fn mmap_whole_file(path: &Path) -> Result<Self, io::Error> {
+        let file = fs::File::open(path)?;
+        MMap::new(
+            file.as_fd(),
+            file.metadata()?.len() as usize,
+            PROT_READ,
+            MAP_PRIVATE,
+            0,
+        )
+        .map_err(|e| e.io_error)
+    }
 }
 
 impl AsRef<[u8]> for MMap {