On Mon, Mar 25, 2024 at 8:10 PM Conor Dooley <conor@xxxxxxxxxx> wrote: > > On Mon, Mar 25, 2024 at 03:54:34PM +0000, Puranjay Mohan wrote: > > LLVM generates bpf_addr_space_cast instruction while translating > > pointers between native (zero) address space and > > __attribute__((address_space(N))). The addr_space=0 is reserved as > > bpf_arena address space. > > > > rY = addr_space_cast(rX, 0, 1) is processed by the verifier and > > converted to normal 32-bit move: wX = wY > > > > rY = addr_space_cast(rX, 1, 0) has to be converted by JIT. > > > > Signed-off-by: Puranjay Mohan <puranjay12@xxxxxxxxx> > > Doesn't compile for allmodconfig: > ../arch/riscv/net/bpf_jit_comp64.c:1086:7: error: call to undeclared function 'insn_is_cast_user'; ISO C99 and later do not support implicit function declarations [-Wimplicit-function-declaration] > > Cheers, > Conor. Yes, I mentioned in the cover letter that a patch is required. It just got merged in bpf-next/master: https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=770546ae9f4c1ae1ebcaf0874f0dd9631d77ec97 So, rebasing on the latest bpf-next/master should fix the issue. Thanks, Puranjay