From: Vincent Li Date: Mon, 18 Aug 2025 16:51:13 +0000 (-0700) Subject: bpftool: Add kernel.kptr_restrict hint for no instructions X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=bf7a6a67050f5d59a674ecc3ecd06d6b09cfec49;p=thirdparty%2Fkernel%2Fstable.git bpftool: Add kernel.kptr_restrict hint for no instructions From bpftool's github repository issue [0]: When a Linux distribution has the kernel.kptr_restrict set to 2, bpftool prog dump jited returns "no instructions returned". This message can be puzzling to bpftool users who are not familiar with kernel BPF internals, so add a small hint for bpftool users to check the kernel.kptr_restrict setting similar to the DUMP_XLATED case. Outside of kernel.kptr_restrict, no instructions could also be returned in case the JIT was disabled. Signed-off-by: Vincent Li Signed-off-by: Daniel Borkmann Acked-by: Daniel Borkmann Link: https://github.com/libbpf/bpftool/issues/184 [0] Link: https://lore.kernel.org/bpf/20250818165113.15982-1-vincent.mc.li@gmail.com --- diff --git a/tools/bpf/bpftool/prog.c b/tools/bpf/bpftool/prog.c index 9722d841abc05..cf18c38796801 100644 --- a/tools/bpf/bpftool/prog.c +++ b/tools/bpf/bpftool/prog.c @@ -714,7 +714,7 @@ prog_dump(struct bpf_prog_info *info, enum dump_mode mode, if (mode == DUMP_JITED) { if (info->jited_prog_len == 0 || !info->jited_prog_insns) { - p_info("no instructions returned"); + p_err("error retrieving jit dump: no instructions returned or kernel.kptr_restrict set?"); return -1; } buf = u64_to_ptr(info->jited_prog_insns);