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knurling-rs / flip-link

Adds zero-cost stack overflow protection to your embedded programs
Apache License 2.0
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consider rejecting negative lengths #67

Open japaric opened 2 years ago

japaric commented 2 years ago

rust-lld will happily link memory.x files that contain lines like these

RAM : ORIGIN = 0x20020000, LENGTH = 1K - 2K

or even

RAM : ORIGIN = 0x20020000, LENGTH = -1K

it seems the behavior is that the value overflows because linking works even if .bss is 1MiB in size.

we could either reject these indicating that there may be a problem in the linker script or that negative lengths are not supported.

if we want to support them then I'm not sure what flip-link behavior should be. transforming either of the above to

RAM : ORIGIN = 0x20020000 - 1K, LENGTH = 1K

does not produce the same binary with a single linker pass

jonathanpallant commented 2 years ago

I agree we should reject these with a clear warning.

Dajamante commented 2 years ago

I can try to do that, since I am on the subtraction issue.