[libc-commits] [libc] [libc] fix issues around stack protector (PR #74567)

[Nick Desaulniers via libc-commits]

nickdesaulniers wrote:

> > I thought certain platforms have a global vs thread local stack canary?
> 
> Could you please give a link to the specifications? I wish I can add links in the comment and gate the attributes accordingly.

This is only from observation; my prior work on the Linux kernel involved getting additional functionality added to clang for the kernel's more exotic stack protector implementation.  The kernel doesn't share the same ABI as userspace, so it can break its own intern ABI whenever, which allows for it to do better than the ABI constrained userspace.

I'd guess maybe the Itanium x86 psABI, ARM ARM, and RISCV psABI might have specific details, but I don't know.  I've only observed behavior by playing with the compiler.

https://github.com/llvm/llvm-project/pull/74567