Current glibc unwinds the shadow stack if it is active: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/x86_64/__longjmp.S;h=22fedc49970eba0ab86cb8dec8

Current glibc unwinds the shadow stack if it is active: https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/x86_64/__longjmp.S;h=22fedc49970eba0ab86cb8dec8411197bec95d37;hb=HEAD#l80 https://sourceware.org/git/?p=glibc.git;a=blob;f=sysdeps/x86... It makes longjmp useless for coroutine switching, although it does not result in other effects of stack unwinding (such as invoking C++ destructors). On Windows, longjmp really unwinds the stack (and maybe this is something influenced by VMS): https://learn.microsoft.com/en-us/cpp/c-runtime-library/reference/longjmp https://learn.microsoft.com/en-us/cpp/c-runtime-library/refe... “In Microsoft C++ code on Windows, longjmp uses the same stack-unwinding semantics as exception-handling code. It's safe to use in the same places that C++ exceptions can be raised.”