[PATCH -next v17 15/20] riscv: signal: validate altstack to reflect Vector

[Heiko Stübner]

Am Montag, 27. März 2023, 18:49:35 CEST schrieb Andy Chiu:
> Some extensions, such as Vector, dynamically change footprint on a
> signal frame, so MINSIGSTKSZ is no longer accurate. For example, an
> RV64V implementation with vlen = 512 may occupy 2K + 40 + 12 Bytes of a
> signal frame with the upcoming support. And processes that do not
> execute any vector instructions do not need to reserve the extra
> sigframe. So we need a way to guard the allocation size of the sigframe
> at process runtime according to current status of V.
> 
> Thus, provide the function sigaltstack_size_valid() to validate its size
> based on current allocation status of supported extensions.
> 
> Signed-off-by: Andy Chiu <andy.chiu at sifive.com>
> Reviewed-by: Conor Dooley <conor.dooley at microchip.com>

Reviewed-by: Heiko Stuebner <heiko.stuebner at vrull.eu>
Tested-by: Heiko Stuebner <heiko.stuebner at vrull.eu>