From 0b20dc1edd88f1eec75567ac971da077b8379818 Mon Sep 17 00:00:00 2001 From: Quentin Monnet Date: Fri, 7 Jul 2023 10:54:24 +0100 Subject: [PATCH] bpftool: Use a local copy of BPF_LINK_TYPE_PERF_EVENT in pid_iter.bpf.c [ Upstream commit 44ba7b30e84fb40da2295e85a6d209e199fdc977 ] In order to allow the BPF program in bpftool's pid_iter.bpf.c to compile correctly on hosts where vmlinux.h does not define BPF_LINK_TYPE_PERF_EVENT (running kernel versions lower than 5.15, for example), define and use a local copy of the enum value. This requires LLVM 12 or newer to build the BPF program. Fixes: cbdaf71f7e65 ("bpftool: Add bpf_cookie to link output") Signed-off-by: Quentin Monnet Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20230707095425.168126-4-quentin@isovalent.com Signed-off-by: Sasha Levin --- tools/bpf/bpftool/skeleton/pid_iter.bpf.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c index 3a4c4f7..26004f0 100644 --- a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c +++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c @@ -24,6 +24,10 @@ struct perf_event___local { u64 bpf_cookie; } __attribute__((preserve_access_index)); +enum bpf_link_type___local { + BPF_LINK_TYPE_PERF_EVENT___local = 7, +}; + extern const void bpf_link_fops __ksym; extern const void bpf_map_fops __ksym; extern const void bpf_prog_fops __ksym; @@ -93,10 +97,13 @@ int iter(struct bpf_iter__task_file *ctx) e.pid = task->tgid; e.id = get_obj_id(file->private_data, obj_type); - if (obj_type == BPF_OBJ_LINK) { + if (obj_type == BPF_OBJ_LINK && + bpf_core_enum_value_exists(enum bpf_link_type___local, + BPF_LINK_TYPE_PERF_EVENT___local)) { struct bpf_link *link = (struct bpf_link *) file->private_data; - if (BPF_CORE_READ(link, type) == BPF_LINK_TYPE_PERF_EVENT) { + if (link->type == bpf_core_enum_value(enum bpf_link_type___local, + BPF_LINK_TYPE_PERF_EVENT___local)) { e.has_bpf_cookie = true; e.bpf_cookie = get_bpf_cookie(link); } -- 2.7.4