Merge pull request #15 from dadada/fix-panic-when-read-from-empty-file

fix panic on empty read from file
DLR-FT · Dec 9, 2022 · d3d68cf · d3d68cf
2 parents 2f69d2b + 24e28b3
commit d3d68cf
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Showing 2 changed files with 15 additions and 15 deletions.
diff --git a/core/src/file.rs b/core/src/file.rs
@@ -1,8 +1,7 @@
 //! Implementation of in-memory files
-use std::io::{Read, Seek, SeekFrom, Write};
 use std::marker::PhantomData;
 use std::mem::size_of;
-use std::os::unix::prelude::{AsRawFd, IntoRawFd, RawFd};
+use std::os::unix::prelude::{AsRawFd, FileExt, IntoRawFd, RawFd};
 
 use anyhow::{anyhow, Result};
 use memfd::{FileSeal, Memfd, MemfdOptions};
@@ -79,21 +78,21 @@ impl<T: Send + Clone + Sized> TempFile<T> {
         // TODO: Use an approach without unsafe
         let bytes =
             unsafe { std::slice::from_raw_parts(value as *const T as *const u8, size_of::<T>()) };
-        let mut file = self.get_memfd()?.into_file();
-        file.seek(SeekFrom::Start(0)).typ(SystemError::Panic)?;
-        file.write_all(bytes)
+        let file = self.get_memfd()?.into_file();
+        file.write_all_at(bytes, 0)
             .map_err(anyhow::Error::from)
             .typ(SystemError::Panic)
     }
 
     /// Returns all of the TempFile's data
     pub fn read(&self) -> TypedResult<T> {
-        let mut buf = Vec::with_capacity(size_of::<T>());
-        let mut file = self.get_memfd()?.into_file();
-        file.seek(SeekFrom::Start(0)).typ(SystemError::Panic)?;
-        file.read_to_end(buf.as_mut()).typ(SystemError::Panic)?;
+        let mut buf = vec![0u8; size_of::<T>()];
+        let buf = buf.as_mut_slice();
+        let file = self.get_memfd()?.into_file();
+        file.read_at(buf, 0).typ(SystemError::Panic)?;
         // TODO: Use an approach without unsafe
-        Ok(unsafe { buf.as_slice().align_to::<T>().1[0].clone() })
+        let aligned = unsafe { buf.align_to::<T>() };
+        Ok(aligned.1[0].clone())
     }
 
     /// Returns a mutable memory map from a TempFile

diff --git a/partition/src/apex.rs b/partition/src/apex.rs
@@ -152,11 +152,12 @@ impl ApexSamplingPortP4 for ApexLinuxPartition {
         sampling_port_id: SamplingPortId,
         message: &mut [ApexByte],
     ) -> Result<(Validity, MessageSize), ErrorReturnCode> {
-        if let Some((port, val)) = SAMPLING_PORTS
-            .read()
-            .unwrap()
-            .get(sampling_port_id as usize - 1)
-        {
+        let read = if let Ok(read) = SAMPLING_PORTS.read() {
+            read
+        } else {
+            return Err(ErrorReturnCode::NotAvailable);
+        };
+        if let Some((port, val)) = read.get(sampling_port_id as usize - 1) {
             if let Some(port) = CONSTANTS.sampling.get(*port) {
                 if message.is_empty() {
                     return Err(ErrorReturnCode::InvalidParam);