intercept SYS_statx on Linux

Author: branchseer

crates/fspy_preload_unix/src/interceptions/linux_syscall.rs

@@ -0,0 +1,32 @@
+use std::ffi::c_long;
+
+use fspy_shared::ipc::AccessMode;
+
+use crate::{
+    client::{convert::PathAt, handle_open},
+    macros::intercept,
+};
+
+intercept!(syscall(64): unsafe extern "C" fn(c_long, args: ...) -> c_long);
+unsafe extern "C" fn syscall(syscall_no: c_long, mut args: ...) -> c_long {
+    // https://github.com/bminor/glibc/blob/efc8642051e6c4fe5165e8986c1338ba2c180de6/sysdeps/unix/sysv/linux/syscall.c#L23
+    let a0 = unsafe { args.arg::<c_long>() };
+    let a1 = unsafe { args.arg::<c_long>() };
+    let a2 = unsafe { args.arg::<c_long>() };
+    let a3 = unsafe { args.arg::<c_long>() };
+    let a4 = unsafe { args.arg::<c_long>() };
+    let a5 = unsafe { args.arg::<c_long>() };
+
+    match syscall_no {
+        libc::SYS_statx => {
+            if let Ok(dirfd) = i32::try_from(a0) {
+                let pathname = a1 as *const u8;
+                unsafe {
+                    handle_open(PathAt(dirfd, pathname), AccessMode::Read);
+                }
+            }
+        }
+        _ => {}
+    }
+    unsafe { syscall::original()(syscall_no, a0, a1, a2, a3, a4, a5) }
+}

crates/fspy_preload_unix/src/interceptions/mod.rs

@@ -3,3 +3,6 @@ mod dirent;
 mod open;
 mod spawn;
 mod stat;
+
+#[cfg(target_os = "linux")]
+mod linux_syscall;