From 7a8a1984ae470a73f0c220a9f306d529fcaa5e74 Mon Sep 17 00:00:00 2001
From: Andrzej Janik <vosen@vosen.pl>
Date: Mon, 8 Sep 2025 20:16:53 +0000
Subject: [PATCH] Handle compressed files in fatbins more correctly

---
 cuda_types/src/dark_api.rs |  6 ++++--
 dark_api/src/fatbin.rs     | 22 ++++++++++++++++------
 2 files changed, 20 insertions(+), 8 deletions(-)

diff --git a/cuda_types/src/dark_api.rs b/cuda_types/src/dark_api.rs
index 1db5b2b..bb7b2cf 100644
--- a/cuda_types/src/dark_api.rs
+++ b/cuda_types/src/dark_api.rs
@@ -45,13 +45,14 @@ pub struct FatbinHeader {
 }
 
 #[repr(C)]
+#[derive(Debug)]
 pub struct FatbinFileHeader {
     pub kind: c_ushort,
     pub version: c_ushort,
     pub header_size: c_uint,
-    pub padded_payload_size: c_uint,
-    pub unknown0: c_uint, // check if it's written into separately
     pub payload_size: c_uint,
+    pub unknown0: c_uint, // check if it's written into separately
+    pub compressed_size: c_uint,
     pub unknown1: c_uint,
     pub unknown2: c_uint,
     pub sm_version: c_uint,
@@ -63,6 +64,7 @@ pub struct FatbinFileHeader {
 }
 
 bitflags! {
+    #[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
     pub struct FatbinFileHeaderFlags: u64 {
         const Is64Bit = 0x0000000000000001;
         const Debug = 0x0000000000000002;
diff --git a/dark_api/src/fatbin.rs b/dark_api/src/fatbin.rs
index e347f26..9488499 100644
--- a/dark_api/src/fatbin.rs
+++ b/dark_api/src/fatbin.rs
@@ -182,13 +182,20 @@ impl<'a> FatbinFile<'a> {
         }
     }
 
-    pub unsafe fn get_payload(self) -> &'a [u8] {
+    pub unsafe fn get_non_compressed_payload(self) -> &'a [u8] {
         let start = std::ptr::from_ref(self.header)
             .cast::<u8>()
             .add(self.header.header_size as usize);
         std::slice::from_raw_parts(start, self.header.payload_size as usize)
     }
 
+    pub unsafe fn get_compressed_payload(self) -> &'a [u8] {
+        let start = std::ptr::from_ref(self.header)
+            .cast::<u8>()
+            .add(self.header.header_size as usize);
+        std::slice::from_raw_parts(start, self.header.compressed_size as usize)
+    }
+
     pub unsafe fn get_or_decompress_content(self) -> Result<Cow<'a, [u8]>, FatbinError> {
         let mut payload = if self
             .header
@@ -203,7 +210,7 @@ impl<'a> FatbinFile<'a> {
         {
             Cow::Owned(unsafe { decompress_zstd(self) }?)
         } else {
-            Cow::Borrowed(unsafe { self.get_payload() })
+            Cow::Borrowed(unsafe { self.get_non_compressed_payload() })
         };
 
         // Remove trailing zeros
@@ -246,7 +253,10 @@ impl<'a> FatbinFileIterator<'a> {
         let this = &*self.file_buffer.as_ptr().cast::<FatbinFileHeader>();
         let next_element = self
             .file_buffer
-            .split_at_checked(this.header_size as usize + this.padded_payload_size as usize)
+            .split_at_checked(
+                this.header_size as usize
+                    + u32::max(this.payload_size, this.compressed_size) as usize,
+            )
             .map(|(_, next)| next);
         self.file_buffer = next_element.unwrap_or(&[]);
         Some(
@@ -267,9 +277,9 @@ pub unsafe fn decompress_lz4(file: FatbinFile) -> Result<Vec<u8>, FatbinError> {
     let mut decompressed_vec = vec![0u8; decompressed_size];
     loop {
         match lz4_sys::LZ4_decompress_safe(
-            file.get_payload().as_ptr() as *const _,
+            file.get_compressed_payload().as_ptr() as *const _,
             decompressed_vec.as_mut_ptr() as *mut _,
-            file.header.payload_size as _,
+            file.header.compressed_size as _,
             decompressed_vec.len() as _,
         ) {
             error if error < 0 => {
@@ -289,7 +299,7 @@ pub unsafe fn decompress_lz4(file: FatbinFile) -> Result<Vec<u8>, FatbinError> {
 
 pub unsafe fn decompress_zstd(file: FatbinFile) -> Result<Vec<u8>, FatbinError> {
     let mut result = Vec::with_capacity(file.header.uncompressed_payload as usize);
-    let payload = file.get_payload();
+    let payload = file.get_compressed_payload();
     match zstd_safe::decompress(&mut result, payload) {
         Ok(actual_size) => {
             result.truncate(actual_size);