Re: [RFC PATCH for 5.2 10/10] rseq/selftests: mips: use break instruction for RSEQ_SIG
From: Paul Burton
Date: Wed Apr 24 2019 - 19:17:31 EST
On Wed, Apr 24, 2019 at 07:12:03PM -0400, Mathieu Desnoyers wrote:
> Does the following comment above the forest of #ifdef work for you ?
> * RSEQ_SIG uses the break instruction. The instruction pattern is:
> * On MIPS:
> * 0350000d break 0x350
> * On nanoMIPS32:
> * 00100350 break 0x350
> * On microMIPS:
> * 0000d407 break 0x350
> * For nanoMIPS32 and microMIPS, the instruction stream is encoded as 16-bit
> * halfwords, so the signature halfwords need to be swapped accordingly for
> * little-endian.
I'd probably just say nanoMIPS rather than nanoMIPS32, because when we
get nanoMIPS64 in the future it'll be a superset of nanoMIPS32 & the
break encoding will be the same.
But otherwise it looks good to me :)