On Mon, Apr 1, 2024 at 7:13 PM Andrii Nakryiko <andrii@xxxxxxxxxx> wrote:
>
> Add a new BPF instruction for resolving per-CPU memory addresses.
>
> New instruction is a special form of BPF_ALU64 | BPF_MOV | BPF_DW, with
> insns->off set to BPF_ADDR_PERCPU (== -1). It resolves provided per-CPU offset
> to an absolute address where per-CPU data resides for "this" CPU.
Fixed the typo s/BPF_DW/BPF_X/ while applying.
I'm still a bit worried that there is no BUILD_BUG_ON
for 32-bit archs while both array and htab perpu gen_lookup
assume sizeof(void*) == 8 in few places:
htab:
*insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0);
array:
*insn++ = BPF_ALU64_IMM(BPF_LSH, BPF_REG_0, 3);
*insn++ = BPF_LDX_MEM(BPF_DW, BPF_REG_0, BPF_REG_0, 0);
Worth following up or I'm overthinking this?
