From: Yonghong Song yhs@fb.com
[ Upstream commit ac4e0e055fee5751c78bba1fc9ce508a6874d916 ]
For a host which has a lower rlimit for max locked memory (e.g., 64KB), the following error occurs in one of our production systems: # /usr/sbin/bpftool prog load /paragon/pods/52877437/home/mark.o \ /sys/fs/bpf/paragon_mark_21 type cgroup/skb \ map idx 0 pinned /sys/fs/bpf/paragon_map_21 libbpf: Error in bpf_object__probe_name():Operation not permitted(1). Couldn't load basic 'r0 = 0' BPF program. Error: failed to open object file
The reason is due to low locked memory during bpf_object__probe_name() which probes whether program name is supported in kernel or not during __bpf_object__open_xattr().
bpftool program load already tries to relax mlock rlimit before bpf_object__load(). Let us move set_max_rlimit() before __bpf_object__open_xattr(), which fixed the issue here.
Fixes: 47eff61777c7 ("bpf, libbpf: introduce bpf_object__probe_caps to test BPF capabilities") Signed-off-by: Yonghong Song yhs@fb.com Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/bpf/bpftool/prog.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index d2be5a06c339..ed8ef5c82256 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -873,6 +873,8 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) } }
+ set_max_rlimit(); + obj = __bpf_object__open_xattr(&attr, bpf_flags); if (IS_ERR_OR_NULL(obj)) { p_err("failed to open object file"); @@ -952,8 +954,6 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) goto err_close_obj; }
- set_max_rlimit(); - err = bpf_object__load(obj); if (err) { p_err("failed to load object file");