query: add uprobe_multi second info call fields

Author: ver-nyan

libbpf-rs/CHANGELOG.md

@@ -1,6 +1,7 @@
 Unreleased
 ----------
-- Added `KprobeMultiLinkInfo` fields that required a second info call.
+- Added `KprobeMultiLinkInfo` & `UprobeMultiLinkInfo` fields that required a
+  second info call.
 
 
 0.26.2

libbpf-rs/src/query.rs

@@ -13,6 +13,7 @@
 use std::ffi::c_void;
 use std::ffi::CStr;
 use std::ffi::CString;
+use std::ffi::OsStr;
 use std::io;
 use std::mem::size_of_val;
 use std::mem::zeroed;
@@ -22,6 +23,8 @@ use std::os::fd::BorrowedFd;
 use std::os::fd::FromRawFd;
 use std::os::fd::OwnedFd;
 use std::os::raw::c_char;
+use std::os::unix::ffi::OsStrExt;
+use std::path::PathBuf;
 use std::ptr;
 use std::time::Duration;
 
@@ -731,12 +734,20 @@ pub struct KprobeMultiLinkInfo {
 pub struct UprobeMultiLinkInfo {
     /// Size of the path.
     pub path_size: u32,
+    /// The absolute file path of the binary being probed.
+    pub path: Option<PathBuf>,
     /// Count of uprobe targets.
     pub count: u32,
     /// Flags for the link.
     pub flags: u32,
     /// PID to which the uprobe is attached.
     pub pid: u32,
+    /// Offsets from the binary.
+    pub offsets: Vec<u64>,
+    /// Offsets of kernel reference counted USDT semaphore.
+    pub ref_ctr_offsets: Vec<u64>,
+    /// Cookies corresponding to the attach addresses.
+    pub cookies: Vec<u64>,
 }
 
 /// Information about a perf event link.
@@ -968,11 +979,45 @@ impl LinkInfo {
                 })
             }
             libbpf_sys::BPF_LINK_TYPE_UPROBE_MULTI => {
+                let mut buf = [0u8; libc::PATH_MAX as usize];
+                let count = unsafe { s.__bindgen_anon_1.uprobe_multi.count } as usize;
+                let mut offsets = vec![0; count];
+                let mut ref_ctr_offsets = vec![0; count];
+                let mut cookies = vec![0; count];
+
+                s.__bindgen_anon_1.uprobe_multi.path = buf.as_mut_ptr() as u64;
+                s.__bindgen_anon_1.uprobe_multi.path_size = buf.len() as u32;
+                s.__bindgen_anon_1.uprobe_multi.offsets = offsets.as_mut_ptr() as u64;
+                s.__bindgen_anon_1.uprobe_multi.ref_ctr_offsets =
+                    ref_ctr_offsets.as_mut_ptr() as u64;
+                s.__bindgen_anon_1.uprobe_multi.cookies = cookies.as_mut_ptr() as u64;
+                let item_ptr: *mut libbpf_sys::bpf_link_info = &mut s;
+                let mut len = size_of_val(&s) as u32;
+                let ret = unsafe {
+                    libbpf_sys::bpf_obj_get_info_by_fd(fd.as_raw_fd(), item_ptr.cast(), &mut len)
+                };
+                if ret != 0 {
+                    return None;
+                }
+
+                let path_size = unsafe { s.__bindgen_anon_1.uprobe_multi.path_size };
+                let path = if path_size != 0 {
+                    let path_ptr = unsafe { s.__bindgen_anon_1.uprobe_multi.path } as *const c_char;
+                    let c_str = unsafe { CStr::from_ptr(path_ptr) };
+                    Some(PathBuf::from(OsStr::from_bytes(c_str.to_bytes())))
+                } else {
+                    None
+                };
+
                 LinkTypeInfo::UprobeMulti(UprobeMultiLinkInfo {
-                    path_size: unsafe { s.__bindgen_anon_1.uprobe_multi.path_size },
+                    path_size,
+                    path,
                     count: unsafe { s.__bindgen_anon_1.uprobe_multi.count },
                     flags: unsafe { s.__bindgen_anon_1.uprobe_multi.flags },
                     pid: unsafe { s.__bindgen_anon_1.uprobe_multi.pid },
+                    offsets,
+                    ref_ctr_offsets,
+                    cookies,
                 })
             }
             libbpf_sys::BPF_LINK_TYPE_SOCKMAP => LinkTypeInfo::SockMap(SockMapLinkInfo {

libbpf-rs/tests/test.rs

@@ -42,6 +42,7 @@ use libbpf_rs::query::KprobeMultiLinkInfo;
 use libbpf_rs::query::LinkTypeInfo;
 use libbpf_rs::query::PerfEventType;
 use libbpf_rs::query::ProgInfoIter;
+use libbpf_rs::query::UprobeMultiLinkInfo;
 use libbpf_rs::AsRawLibbpf;
 use libbpf_rs::Iter;
 use libbpf_rs::KprobeMultiOpts;
@@ -2088,18 +2089,23 @@ fn test_object_uprobe_multi_with_non_default_opts() {
     let prog = get_prog_mut(&mut obj, "handle__uprobe_multi_with_non_default_opts");
     let func_pattern = "";
 
-    let pid = unsafe { libc::getpid() };
-    let path = current_exe().expect("failed to find executable name");
+    let current_pid = unsafe { libc::getpid() };
+    let current_path = current_exe().expect("failed to find executable name");
+    let syms_opt = vec![
+        "non_default_opts_multi_uprobe_func_with_opts_func_1".to_string(),
+        "non_default_opts_multi_uprobe_func_with_opts_func_2".to_string(),
+    ];
+    let ref_ctr_offsets_opt = vec![2, 4];
+    let cookies_opt = vec![5, 2];
     let opts = UprobeMultiOpts {
-        syms: vec![
-            "non_default_opts_multi_uprobe_func_with_opts_func_1".to_string(),
-            "non_default_opts_multi_uprobe_func_with_opts_func_2".to_string(),
-        ],
+        syms: syms_opt.clone(),
+        ref_ctr_offsets: ref_ctr_offsets_opt.clone(),
+        cookies: cookies_opt.clone(),
         ..Default::default()
     };
 
-    let _link = prog
-        .attach_uprobe_multi_with_opts(pid, path, func_pattern, opts)
+    let link = prog
+        .attach_uprobe_multi_with_opts(current_pid, &current_path, func_pattern, opts)
         .expect("failed to attach uprobe multi");
 
     non_default_opts_multi_uprobe_func_with_opts_func_1();
@@ -2119,6 +2125,37 @@ fn test_object_uprobe_multi_with_non_default_opts() {
     );
 
     assert_eq!(result, 2);
+
+    let link_info = link.info().expect("failed to get uprobe_multi link info");
+    let LinkTypeInfo::UprobeMulti(uprobe_multi) = link_info.info else {
+        panic!(
+            "Expected LinkTypeInfo::UprobeMulti for uprobe_multi, got: {:?}",
+            link_info.info
+        );
+    };
+
+    let UprobeMultiLinkInfo {
+        path,
+        count,
+        pid,
+        offsets,
+        ref_ctr_offsets,
+        cookies,
+        ..
+    } = uprobe_multi;
+    assert_eq!(path.as_ref(), Some(&current_path));
+    assert_eq!(pid, current_pid as u32);
+    assert_eq!(count, syms_opt.len() as u32);
+    for (actual, sym) in zip(offsets, syms_opt) {
+        let expected = get_symbol_offset(&current_path, &sym).unwrap();
+        assert_eq!(actual, expected as u64);
+    }
+    for (actual, expected) in zip(ref_ctr_offsets, ref_ctr_offsets_opt) {
+        assert_eq!(actual, expected as u64);
+    }
+    for (actual, expected) in zip(cookies, cookies_opt) {
+        assert_eq!(actual, expected);
+    }
 }
 
 #[tag(root)]