Messages in this thread | | | From | David Laight <> | Subject | RE: [PATCH v2 00/11] x86-64: Stack protector and percpu improvements | Date | Sun, 29 Oct 2023 21:42:41 +0000 |
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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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