Fix ELF patch cache identity and mapping lifetime

litebox_common_linux/src/errno/mod.rs

@@ -186,6 +186,7 @@ impl From<litebox::net::errors::CloseError> for Errno {
 impl From<litebox::fs::errors::ReadError> for Errno {
     fn from(value: litebox::fs::errors::ReadError) -> Self {
         match value {
+            litebox::fs::errors::ReadError::ClosedFd => Errno::EBADF,
             litebox::fs::errors::ReadError::NotAFile => Errno::EISDIR,
             litebox::fs::errors::ReadError::NotForReading => Errno::EBADF,
             litebox::fs::errors::ReadError::Io => Errno::EIO,
@@ -337,6 +338,7 @@ impl From<litebox::path::ConversionError> for Errno {
 impl From<litebox::fs::errors::FileStatusError> for Errno {
     fn from(value: litebox::fs::errors::FileStatusError) -> Self {
         match value {
+            litebox::fs::errors::FileStatusError::ClosedFd => Errno::EBADF,
             litebox::fs::errors::FileStatusError::PathError(path_error) => path_error.into(),
             _ => unimplemented!(),
         }

litebox_common_linux/src/lib.rs

@@ -101,7 +101,7 @@ pub mod ioctl {
 
 bitflags::bitflags! {
     /// Desired memory protection of a memory mapping.
-    #[derive(PartialEq, Debug)]
+    #[derive(Clone, Copy, PartialEq, Debug)]
     pub struct ProtFlags: core::ffi::c_int {
         /// Pages cannot be accessed.
         const PROT_NONE = 0;
@@ -128,7 +128,7 @@ bitflags::bitflags! {
 
 bitflags::bitflags! {
     /// Additional parameters for [`mmap`].
-    #[derive(Debug)]
+    #[derive(Copy, Clone, Debug)]
     pub struct MapFlags: core::ffi::c_int {
         /// Share this mapping. Mutually exclusive with `MAP_PRIVATE`.
         const MAP_SHARED = 0x1;

litebox_common_linux/src/loader.rs

@@ -93,6 +93,13 @@ struct TrampolineHeader32 {
     trampoline_size: u32,
 }
 
+/// Size in bytes of the trampoline footer for the target architecture.
+pub const TRAMPOLINE_HEADER_SIZE: usize = if cfg!(target_pointer_width = "64") {
+    size_of::<TrampolineHeader64>()
+} else {
+    size_of::<TrampolineHeader32>()
+};
+
 const CLASS: elf::file::Class = if cfg!(target_pointer_width = "64") {
     elf::file::Class::ELF64
 } else {
@@ -265,11 +272,7 @@ impl ElfParsedFile {
 
         let file_size = file.size().map_err(ElfParseError::Io)?;
 
-        let header_size = if cfg!(target_pointer_width = "64") {
-            size_of::<TrampolineHeader64>()
-        } else {
-            size_of::<TrampolineHeader32>()
-        };
+        let header_size = TRAMPOLINE_HEADER_SIZE;
 
         // File must be large enough to contain the header
         if file_size < header_size as u64 {
@@ -279,7 +282,7 @@ impl ElfParsedFile {
 
         // Read the header from the end of the file
         let header_offset = file_size - header_size as u64;
-        let mut header_buf = [0u8; size_of::<TrampolineHeader64>()]; // Max header size
+        let mut header_buf = [0u8; TRAMPOLINE_HEADER_SIZE];
         file.read_at(header_offset, &mut header_buf[..header_size])
             .map_err(ElfParseError::Io)?;
 

litebox_shim_linux/Cargo.toml

@@ -17,6 +17,7 @@ ringbuf = { version = "0.4.8", default-features = false, features = ["alloc"] }
 zerocopy = { version = "0.8", default-features = false, features = ["derive"] }
 litebox_syscall_rewriter = { version = "0.1.0", path = "../litebox_syscall_rewriter", default-features = false }
 object = { version = "0.36.7", default-features = false, features = ["elf", "read_core"] }
+rangemap = { version = "1.5.1", features = ["const_fn"] }
 
 [features]
 alarm_fallback = []

litebox_shim_linux/src/lib.rs

@@ -1197,7 +1197,7 @@ struct GlobalState<Platform: ShimPlatform> {
     /// UNIX domain socket address table
     unix_addr_table: litebox::sync::RwLock<Platform, syscalls::unix::UnixAddrTable<Platform>>,
     /// Per-process collection of ELF patching state for runtime syscall rewriting.
-    elf_patch_cache: litebox::sync::Mutex<Platform, syscalls::mm::ElfPatchCache>,
+    elf_patch_cache: litebox::sync::Mutex<Platform, syscalls::mm::ElfPatchCache<Platform>>,
 }
 
 struct Task<Platform: ShimPlatform> {

litebox_shim_linux/src/syscalls/file.rs

@@ -927,10 +927,9 @@ impl<Platform: ShimPlatform> Task<Platform> {
 
         match consumed {
             AnyTypedFd::Fs(fd) => {
-                if let Ok(raw_fd) = i32::try_from(raw_fd) {
-                    self.finalize_elf_patch(raw_fd);
-                }
-                files.fs.close(&fd).map_err(Errno::from)
+                let result = files.fs.close(&fd).map_err(Errno::from);
+                self.finalize_elf_patch(fd);
+                result
             }
             AnyTypedFd::Network(fd) => self.global.close_socket(&self.wait_cx(), fd),
             AnyTypedFd::Pipes(fd) => self.global.close_linux_pipe(&fd),