Commit 623d4c8a authored by Yonghong Song's avatar Yonghong Song Committed by Greg Kroah-Hartman

tools/bpftool: move set_max_rlimit() before __bpf_object__open_xattr()

[ Upstream commit ac4e0e05 ]

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: 47eff617 ("bpf, libbpf: introduce bpf_object__probe_caps to test BPF capabilities")
Signed-off-by: default avatarYonghong Song <yhs@fb.com>
Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 20453017
...@@ -873,6 +873,8 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) ...@@ -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); obj = __bpf_object__open_xattr(&attr, bpf_flags);
if (IS_ERR_OR_NULL(obj)) { if (IS_ERR_OR_NULL(obj)) {
p_err("failed to open object file"); p_err("failed to open object file");
...@@ -952,8 +954,6 @@ static int load_with_options(int argc, char **argv, bool first_prog_only) ...@@ -952,8 +954,6 @@ static int load_with_options(int argc, char **argv, bool first_prog_only)
goto err_close_obj; goto err_close_obj;
} }
set_max_rlimit();
err = bpf_object__load(obj); err = bpf_object__load(obj);
if (err) { if (err) {
p_err("failed to load object file"); p_err("failed to load object file");
......
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