Re: [PATCH v21 bpf-next 18/23] libbpf: Add SEC name for xdp_mb programs
From: Andrii Nakryiko <hidden>
Date: 2022-01-10 02:16:52
Also in:
bpf
On Sun, Jan 9, 2022 at 7:05 AM Lorenzo Bianconi [off-list ref] wrote:
Introduce support for the following SEC entries for XDP multi-buff
property:
- SEC("xdp_mb/")
- SEC("xdp_devmap_mb/")
- SEC("xdp_cpumap_mb/")Libbpf seemed to went with .<suffix> rule (e.g., fentry.s for sleepable, seems like we'll have kprobe.multi or something along those lines as well), so let's stay consistent and call this "xdp_mb", "xdp_devmap.mb", "xdp_cpumap.mb" (btw, is "mb" really all that recognizable? would ".multibuf" be too verbose?). Also, why the "/" part? Also it shouldn't be "sloppy" either. Neither expected attach type should be optional. Also not sure SEC_ATTACHABLE is needed. So at most it should be SEC_XDP_MB, probably.
quoted hunk ↗ jump to hunk
Acked-by: Toke Hoiland-Jorgensen <redacted> Acked-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> --- tools/lib/bpf/libbpf.c | 8 ++++++++ 1 file changed, 8 insertions(+)diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 7f10dd501a52..c93f6afef96c 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c@@ -235,6 +235,8 @@ enum sec_def_flags { SEC_SLEEPABLE = 8, /* allow non-strict prefix matching */ SEC_SLOPPY_PFX = 16, + /* BPF program support XDP multi-buff */ + SEC_XDP_MB = 32, }; struct bpf_sec_def {@@ -6562,6 +6564,9 @@ static int libbpf_preload_prog(struct bpf_program *prog, if (def & SEC_SLEEPABLE) opts->prog_flags |= BPF_F_SLEEPABLE; + if (prog->type == BPF_PROG_TYPE_XDP && (def & SEC_XDP_MB)) + opts->prog_flags |= BPF_F_XDP_MB;
I'd say you don't even need SEC_XDP_MB flag at all, you can just check that prog->sec_name is one of "xdp.mb", "xdp_devmap.mb" or "xdp_cpumap.mb" and add the flag. SEC_XDP_MB doesn't seem generic enough to warrant a flag.
quoted hunk ↗ jump to hunk
+ if ((prog->type == BPF_PROG_TYPE_TRACING || prog->type == BPF_PROG_TYPE_LSM || prog->type == BPF_PROG_TYPE_EXT) && !prog->attach_btf_id) {@@ -8600,8 +8605,11 @@ static const struct bpf_sec_def section_defs[] = { SEC_DEF("lsm.s/", LSM, BPF_LSM_MAC, SEC_ATTACH_BTF | SEC_SLEEPABLE, attach_lsm), SEC_DEF("iter/", TRACING, BPF_TRACE_ITER, SEC_ATTACH_BTF, attach_iter), SEC_DEF("syscall", SYSCALL, 0, SEC_SLEEPABLE), + SEC_DEF("xdp_devmap_mb/", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE | SEC_XDP_MB), SEC_DEF("xdp_devmap/", XDP, BPF_XDP_DEVMAP, SEC_ATTACHABLE), + SEC_DEF("xdp_cpumap_mb/", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE | SEC_XDP_MB), SEC_DEF("xdp_cpumap/", XDP, BPF_XDP_CPUMAP, SEC_ATTACHABLE), + SEC_DEF("xdp_mb/", XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX | SEC_XDP_MB), SEC_DEF("xdp", XDP, BPF_XDP, SEC_ATTACHABLE_OPT | SEC_SLOPPY_PFX), SEC_DEF("perf_event", PERF_EVENT, 0, SEC_NONE | SEC_SLOPPY_PFX), SEC_DEF("lwt_in", LWT_IN, 0, SEC_NONE | SEC_SLOPPY_PFX), --2.33.1