On 2/16/21 12:30 AM, KP Singh wrote:
On Mon, Feb 15, 2021 at 11:42 PM Ilya Leoshkevich <iii@xxxxxxxxxxxxx> wrote:
[...]
How does the situation look on other archs when they need to
implement this in future?
Mainly asking whether it would be better to instead to move this
logic into the verifier
instead, so it'll be consistent across all archs.
I have exactly the same check in my s390 wip patch.
So having a common solution would be great.
We do rewrites for various cases like div/mod handling, perhaps would
be
best to emit an explicit BPF_MOV32_REG(insn->dst_reg, insn->dst_reg)
there,
see the fixup_bpf_calls().
Agreed, this would be better.
How about BPF_ZEXT_REG? Then arches that don't need this (I think
aarch64's instruction always zero-extends) can detect this using
insn_is_zext() and skip such insns.
+1
That would be nicer indeed.
