[PATCH v2] riscv: Discard vector state on syscalls

[Björn Töpel]

Björn Töpel <bjorn at kernel.org> writes:

> From: Björn Töpel <bjorn at rivosinc.com>
>
> The RISC-V vector specification states:
>   Executing a system call causes all caller-saved vector registers
>   (v0-v31, vl, vtype) and vstart to become unspecified.

A bit of a corner case, but this will make sigreturn syscalls discard
the vector state as well.

Is that an issue? E.g. a user cannot build userspace context switching
application. Does arm64 SVE handle sigreturn in a special way?


Björn