[Backtracing][Linux] Properly align the stacks. #66627
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We have two stacks that we set up during crash handling, both of which were potentially misaligned. This only tripped us up on Ubuntu 20.04 on aarch64 - my guess is that maybe `clone()` aligns the stack pointer on newer kernels which is why we didn't see it on 22.04. rdar://110743884
al45tair
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@swift-ci Please test |
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Explanation: When handling a crash, we create a background thread and a new process; both of these require us to allocate space for a stack, which we were doing, but we weren't specifying any alignment on the buffers used for that. This didn't work on Ubuntu 20.04 on aarch64, presumably because the kernel on that version doesn't round down the stack pointer in case it's misaligned. |
mikeash
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airspeedswift
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tomerd
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DougGregor
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We have two stacks that we set up during crash handling, both of which were potentially misaligned. This only tripped us up on Ubuntu 20.04 on aarch64 - my guess is that maybe
clone()aligns the stack pointer on newer kernels which is why we didn't see it on 22.04.rdar://110743884