Re: [PATCH v4 5/5] powerpc/vdso: Wire up getrandom() vDSO implementation on PPC64

Jason A. Donenfeld
2024-09-02T12:41:46Z

On Mon, Sep 02, 2024 at 02:04:42PM +0200, Christophe Leroy wrote:
> SYM_FUNC_START(__arch_chacha20_blocks_nostack)
> #ifdef __powerpc64__
> - blr
> + std r5, -216(r1)
> +
> + std r14, -144(r1)
> + std r15, -136(r1)
> + std r16, -128(r1)
> + std r17, -120(r1)
> + std r18, -112(r1)
> + std r19, -104(r1)
> + std r20, -96(r1)
> + std r21, -88(r1)
> + std r22, -80(r1)
> + std r23, -72(r1)
> + std r24, -64(r1)
> + std r25, -56(r1)
> + std r26, -48(r1)
> + std r27, -40(r1)
> + std r28, -32(r1)
> + std r29, -24(r1)
> + std r30, -16(r1)
> + std r31, -8(r1)
> #else
> stwu r1, -96(r1)
> stw r5, 20(r1)
> +#ifdef __BIG_ENDIAN__
> stmw r14, 24(r1)
> +#else
> + stw r14, 24(r1)
> + stw r15, 28(r1)
> + stw r16, 32(r1)
> + stw r17, 36(r1)
> + stw r18, 40(r1)
> + stw r19, 44(r1)
> + stw r20, 48(r1)
> + stw r21, 52(r1)
> + stw r22, 56(r1)
> + stw r23, 60(r1)
> + stw r24, 64(r1)
> + stw r25, 68(r1)
> + stw r26, 72(r1)
> + stw r27, 76(r1)
> + stw r28, 80(r1)
> + stw r29, 84(r1)
> + stw r30, 88(r1)
> + stw r31, 92(r1)
> +#endif
> +#endif

This confuses me. Why are you adding code to the !__powerpc64__ branch
in this commit? (Also, why does stmw not work on LE?)