On Tue, 14 May 2024 at 20:32, Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
> Why does it do that disgusting
>
> struct bpf_array *array = container_of(map, struct bpf_array, map);
> ...
> *insn++ = BPF_ALU32_IMM(BPF_AND, BPF_REG_0, array->index_mask);
>
> thing? As far as I can tell, a bpf map can be embedded in many
> different structures, not just that 'bpf_array' thing.
Bah. It still needs to do that array->elem_size, so it's not just the
spectre-v1 code that needs that 'bpf_array' thing.
And the non-percpu case seems to do all the same contortions, so I
don't know why the new percpu array would show issues.
Oh well. I guess the bpf people will figure it out once they come back
from "partying at LSFMM" as you put it.
Linus
