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SubjectRE: The killing of ideal_nops[]
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From: Peter Zijlstra <peterz@infradead.org>
...
> Below is the latest version which I just pushed out to my git tree so
> that the robots can have a go at it.

Why not delete the indirection table?
So you end up with:

> +#ifndef CONFIG_64BIT
> +
> +/*
> + * Generic 32bit nops from GAS:
> + *
> + * 1: nop
> + * 2: movl %esi,%esi
> + * 3: leal 0x00(%esi),%esi
> + * 4: leal 0x00(,%esi,1),%esi
> + * 5: leal %ds:0x00(,%esi,1),%esi
> + * 6: leal 0x00000000(%esi),%esi
> + * 7: leal 0x00000000(,%esi,1),%esi
> + * 8: leal %ds:0x00000000(,%esi,1),%esi
> *
> - * *_NOP5_ATOMIC must be a single instruction.
> + * Except 5 and 8, which are DS prefixed 4 and 7 resp, where GAS would emit 2
> + * nop instructions.
> */
> +#define BYTES_NOP1 0x90
> +#define BYTES_NOP2 0x89,0xf6
> +#define BYTES_NOP3 0x8d,0x76,0x00
> +#define BYTES_NOP4 0x8d,0x74,0x26,0x00
> +#define BYTES_NOP5 0x3e,BYTES_NOP4
> +#define BYTES_NOP6 0x8d,0xb6,0x00,0x00,0x00,0x00
> +#define BYTES_NOP7 0x8d,0xb4,0x26,0x00,0x00,0x00,0x00
> +#define BYTES_NOP8 0x3e,BYTES_NOP7

const unsigned char const x86_nops[8][8] = {
{ BYTES_NOP1 },
{ BYTES_NOP2 },
{ BYTES_NOP3 },
{ BYTES_NOP4 },
{ BYTES_NOP5 },
{ BYTES_NOP6 },
{ BYTES_NOP7 },
{ BYTES_NOP8 }
};

The rest of the patch may not need changing.

David

-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)

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