> I really disagree.
> I really disagree. Rust does not allow uninitialized values by design - end of story. If a piece of Rust code let's uninitialized values bleed through, then it is broken. The semantics of Rust demands this. (OpenSSL on the other hand only broke/Overrode OpenBSD's malloc - they didn't break C.) I'm not familiar enough with Rust (mostly on account of being more partial to Go...), so I will gladly stand corrected if I'm missing anything here. If the OpenSSL did the same thing they did in C -- implement their own, custom allocator over a pre-allocated memory region, would anything in Rust prevent them from the same sequence of events? That is: 1. Program receives a packet and wants 100 bytes of memory for it. 2. It asks custom_allocator to give it a 100 byte chunk. custom_allocator gives it a fresh 100 byte chunk, which is correctly initialized because this is Rust. 3. Program is done with that chunk... 4. ...but custom_allocator is not. It marks the 100 byte chunk as free for it to use them again, but continues to retain ownership and does not clear its contents. 5. Program receives a packet that claims it has 100 bytes of payload, so it asks custom_allocator to give it a chunk of 100 bytes. custom_allocator gives it the same chunk as before , without asking the Rust runtime for another (initialized!) chunk. Program is free to roam around those 100 bytes, too. I.e. the semantics of Rust do not allow for data to be uninitialized, but custom_allocator sidesteps that.
Posted by weland on Mar 12, 2015, 1:22 PM
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[FEATURE] Allow users to configure which shell the Bash tool uses or inherit initial shell
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> I really disagree.
> I really disagree. Rust does not allow uninitialized values by design - end of story. If a piece of Rust code let's uninitialized values bleed through, then it is broken. The semantics of Rust demands this. (OpenSSL on the other hand only broke/Overrode OpenBSD's malloc - they didn't break C.) I'm not familiar enough with Rust (mostly on account of being more partial to Go...), so I will gladly stand corrected if I'm missing anything here. If the OpenSSL did the same thing they did in C -- implement their own, custom allocator over a pre-allocated memory region, would anything in Rust prevent them from the same sequence of events? That is: 1. Program receives a packet and wants 100 bytes of memory for it. 2. It asks custom_allocator to give it a 100 byte chunk. custom_allocator gives it a fresh 100 byte chunk, which is correctly initialized because this is Rust. 3. Program is done with that chunk... 4. ...but custom_allocator is not. It marks the 100 byte chunk as free for it to use them again, but continues to retain ownership and does not clear its contents. 5. Program receives a packet that claims it has 100 bytes of payload, so it asks custom_allocator to give it a chunk of 100 bytes. custom_allocator gives it the same chunk as before , without asking the Rust runtime for another (initialized!) chunk. Program is free to roam around those 100 bytes, too. I.e. the semantics of Rust do not allow for data to be uninitialized, but custom_allocator sidesteps that.
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