Messages in this thread | | | Date | Fri, 17 Mar 2023 13:03:36 +0000 | From | Mark Brown <> | Subject | Re: [PATCH 3/4] arm64/signal: Add tpidr2/za/zt sigframe size in comment |
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On Fri, Mar 17, 2023 at 08:49:14PM +0800, Dongxu Sun wrote:
> * 0x8a0 sve_context (vl <= 64) (optional) > + * 0x10 tpidr2_context (optional) > + * 0x10 za_context (optional)
The size of the ZA context is variable, going with what the SVE has a VL which might fit into the base context should be included but that's complicated what with it likely appearing after another variably sized frame.
> + * 0x10 zt_context (optional)
The ZT context is never this small, it's always got register contents if present.
> * 0x20 extra_context (optional) > * 0x10 terminator (null _aarch64_ctx) > * > - * 0x510 (reserved for future allocation) > + * 0x4e0 (reserved for future allocation)
TBH I'm not sure this comment is actually useful or helpful, it's already not fully taking into account the variablility of the SVE frame size (quoting a fixed value) and with the way we allocate things once we've gone into the extra_context we'll allocate new frames from there so even smaller frames like the tpidr2_context will go there. I'm not sure trying to suggest a layout/ordering is clarifying anything for anyone. [unhandled content-type:application/pgp-signature] | |