6.4-stable review patch. If anyone has any objections, please let me know.
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From: Quentin Monnet quentin@isovalent.com
[ 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 quentin@isovalent.com Signed-off-by: Andrii Nakryiko andrii@kernel.org Link: https://lore.kernel.org/bpf/20230707095425.168126-4-quentin@isovalent.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 3a4c4f7d83d86..26004f0c5a6ae 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); }