wasi-common: change behavior of path_readlink to truncate on too-small buffer #6225
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…l buffers this is the same behavior as exists in posix readlink(2)
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truncation behavior is backported to upstream in bytecodealliance/wasmtime#6225
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…l buffers (bytecodealliance#6225) this is the same behavior as exists in posix readlink(2)
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truncation behavior is backported to upstream in bytecodealliance#6225
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truncation behavior is backported to upstream in bytecodealliance#6225
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This is the same behavior on a too-small buffer as posix readlink(2).
The correct way to call readlink(2), and therefore path_readlink, is to call it multiple times with incrementally larger buffers until the bytes returned is smaller than the buffer passed in, to ensure the value is not being truncated. Userlands are used to this restriction.
Thankfully this nonsense goes away, thanks to the component model, in preview 2, where path_readlink just gives a string. Only the (host) component interfacing with a posix
readlink(2)needs to do the truncation detection dance.