Stage2: wasm-linker - Place stack at the beginning of the linear memory#10572
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andrewrk merged 2 commits intoziglang:masterfrom Jan 12, 2022
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Stage2: wasm-linker - Place stack at the beginning of the linear memory#10572andrewrk merged 2 commits intoziglang:masterfrom
andrewrk merged 2 commits intoziglang:masterfrom
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By placing the stack at the start of the memory section, we prevent the runtime from silently overwriting the global declarations and instead trap. We do however, allow users to overwrite this behavior by setting the global-base, which puts the stack at the end of the memory section and the static data at the base that was specified. The reason a user would want to do this, is when they are sure the stack will not overflow and they want to decrease the binary size as the offsets to the static memory are generally smaller. (Having the stack in front, means that accessing the memory after the stack has a bigger offset when loading/storing from memory).
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Stage2: wasm-linker - Place stack at the beginning of the linear memory
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Stage2: wasm-linker - Place stack at the beginning of the linear memory
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By placing the stack at the start of the memory section, we prevent the runtime from silently overwriting the static memory and instead trap on a stack overflow.
We do, however, allow users to overwrite this behavior by setting the
global-baseflag, which puts the stack at the end of the memory section and the static data at the base that was specified.The reason a user would want to do this is when they need to put the static data at a specific address. Another benefit of doing so it has a side effect of lower binary size.
(Having the stack in front, means that accessing the memory after the stack has a bigger offset when loading/storing from memory. Bigger offsets mean it takes more bytes to represent the instruction).
Note: While we used to append this flag by default to wasm-ld, we only did this for
build-exeand had no way to overwrite such behavior.This PR implements it for both the self-hosted linker and the linker frontend for stage1.
Closes #10567