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Remove some asserts in MemoryImage::new (#3874)

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This commit removes some `.unwrap()` annotations around casts between
integers to either be infallible or handle errors. This fixes a panic in
a fuzz test case that popped out for memory64-using modules. The actual
issue here is pretty benign, we were just too eager about assuming
things fit into 32-bit.
This commit is contained in:
Alex Crichton
2022-03-02 14:04:59 -06:00
committed by GitHub
parent 2f48c890a8
commit 1fb71fa1ea
1 changed files with 5 additions and 3 deletions
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8
crates/runtime/src/cow.rs
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@@ -90,10 +90,12 @@ impl MemoryImage {
) -> Result<Option<MemoryImage>> { ) -> Result<Option<MemoryImage>> {
// Sanity-check that various parameters are page-aligned. // Sanity-check that various parameters are page-aligned.
let len = data.len(); let len = data.len();
let offset = u32::try_from(offset).unwrap(); assert_eq!(offset % u64::from(page_size), 0);
assert_eq!(offset % page_size, 0);
assert_eq!((len as u32) % page_size, 0); assert_eq!((len as u32) % page_size, 0);
let linear_memory_offset = usize::try_from(offset).unwrap(); let linear_memory_offset = match usize::try_from(offset) {
Ok(offset) => offset,
Err(_) => return Ok(None),
};
// If a backing `mmap` is present then `data` should be a sub-slice of // If a backing `mmap` is present then `data` should be a sub-slice of
// the `mmap`. The sanity-checks here double-check that. Additionally // the `mmap`. The sanity-checks here double-check that. Additionally