Remove pointer authentication from fibers#13118
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alexcrichton wants to merge 1 commit intobytecodealliance:mainfrom
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Remove pointer authentication from fibers#13118alexcrichton wants to merge 1 commit intobytecodealliance:mainfrom
alexcrichton wants to merge 1 commit intobytecodealliance:mainfrom
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This commit removes the pointer authentication instructions from our fiber implementation. There's more rationale in bytecodealliance#12778 for this but the basic problems are: * Android uses the "A" key to sign return addresses, but the "A" key differs between threads. This causes resuming fibers across threads to crash. * Rust does not provide the ability to know when pointer authentication is enabled, nor does it have a way of enabling pointer authentication for generated code on stable. * We can't currently find reference documentation for which key should be used ABI-wise for each target, nor why the Android "A" key is changing across threads in the same process. Overall it seems like we're a bit too far out on a limb trying to enable this. In the future if all Rust code, except this inline assembly, uses pointer authentication we'll be in a good spot to reevaluate this perhaps. Until that day though it seems premature to enable this. Closes bytecodealliance#12778
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This commit removes the pointer authentication instructions from our fiber implementation. There's more rationale in #12778 for this but the basic problems are:
Overall it seems like we're a bit too far out on a limb trying to enable this. In the future if all Rust code, except this inline assembly, uses pointer authentication we'll be in a good spot to reevaluate this perhaps. Until that day though it seems premature to enable this.
Closes #12778