On Tue, Sep 05, 2023 at 09:06:17PM +0000, Puranjay Mohan wrote:
> The cpuv4 added a new unconditional bswap instruction with following
> behaviour:
>
> BPF_ALU64 | BPF_TO_LE | BPF_END with imm = 16/32/64 means:
> dst = bswap16(dst)
> dst = bswap32(dst)
> dst = bswap64(dst)
>
> As we already support converting to big-endian from little-endian we can
> use the same for unconditional bswap.
> Since ARM32 is always little-endian, just treat the unconditional scenario
This is not true. Arm32 BPF is disabled for BE32 but not for BE8. It's
entirely possible to build a kernel using BE8 for ARMv7 and have the
BPF JIT enabled:
select HAVE_EBPF_JIT if !CPU_ENDIAN_BE32
So it's not true to say "Since ARM32 is always little-endian".
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