On Fri, Mar 26, 2021 at 7:42 AM Christophe Leroy <christophe.leroy@xxxxxxxxxx> wrote: > > > > Le 22/03/2021 à 18:53, Andrii Nakryiko a écrit : > > On Mon, Mar 22, 2021 at 9:37 AM Christophe Leroy > > <christophe.leroy@xxxxxxxxxx> wrote: > >> > >> This series implements extended BPF on powerpc32. For the implementation > >> details, see the patch before the last. > >> > >> The following operations are not implemented: > >> > >> case BPF_ALU64 | BPF_DIV | BPF_X: /* dst /= src */ > >> case BPF_ALU64 | BPF_MOD | BPF_X: /* dst %= src */ > >> case BPF_STX | BPF_XADD | BPF_DW: /* *(u64 *)(dst + off) += src */ > >> > >> The following operations are only implemented for power of two constants: > >> > >> case BPF_ALU64 | BPF_MOD | BPF_K: /* dst %= imm */ > >> case BPF_ALU64 | BPF_DIV | BPF_K: /* dst /= imm */ > >> > >> Below are the results on a powerpc 885: > >> - with the patch, with and without bpf_jit_enable > >> - without the patch, with bpf_jit_enable (ie with CBPF) > >> > >> With the patch, with bpf_jit_enable = 1 : > >> > >> [ 60.826529] test_bpf: Summary: 378 PASSED, 0 FAILED, [354/366 JIT'ed] > >> [ 60.832505] test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED > >> > >> With the patch, with bpf_jit_enable = 0 : > >> > >> [ 75.186337] test_bpf: Summary: 378 PASSED, 0 FAILED, [0/366 JIT'ed] > >> [ 75.192325] test_bpf: test_skb_segment: Summary: 2 PASSED, 0 FAILED > >> > >> Without the patch, with bpf_jit_enable = 1 : > >> > >> [ 186.112429] test_bpf: Summary: 371 PASSED, 7 FAILED, [119/366 JIT'ed] > >> > >> Couldn't run test_progs because it doesn't build (clang 11 crashes during the build). > > > > Can you please try checking out the latest clang from sources and use > > that one instead? > > The crash is fixed, it builds one step more, then fails at: > > [root@PC-server-ldb bpf]# make CROSS_COMPILE=ppc-linux- ARCH=powerpc V=1 > /root/gen_ldb/linux-powerpc/tools/testing/selftests/bpf/host-tools/sbin/bpftool gen skeleton > /root/gen_ldb/linux-powerpc/tools/testing/selftests/bpf/atomic_bounds.o > > /root/gen_ldb/linux-powerpc/tools/testing/selftests/bpf/atomic_bounds.skel.h > libbpf: elf: endianness mismatch in atomic_bounds. > Error: failed to open BPF object file: Endian mismatch > > I'm cross-building on x86 for powerpc/32 yeah, I'm not sure selftests/bpf supports cross-compiling. bpftool got some patches recently to enable cross-compiling, but probably not selftests/bpf. > > [root@PC-server-ldb bpf]# file atomic_bounds.o > atomic_bounds.o: ELF 64-bit MSB relocatable, eBPF, version 1 (SYSV), with debug_info, not stripped > > Christophe
