RE: [PATCH v2 00/11] x86-64: Stack protector and percpu improvements

David Laight
2023-10-29T21:42:37Z

From: Brian Gerst
> Sent: 26 October 2023 17:01
>
> Currently, x86-64 uses an unusual percpu layout, where the percpu section
> is linked at absolute address 0. The reason behind this is that older GCC
> versions placed the stack protector (if enabled) at a fixed offset from the
> GS segment base. Since the GS segement is also used for percpu variables,
> this forced the current layout.
>
> GCC since version 8.1 supports a configurable location for the stack
> protector value, which allows removal of the restriction on how the percpu
> section is linked. This allows the percpu section to be linked
> normally, like most other architectures. In turn, this allows removal
> of code that was needed to support the zero-based percpu section.

I didn't think the minimum gcc version was anything like 8.1.
I'm using 7.5.0 and I don't think that is the oldest version.

David

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