TWxSoftware/twx-linux
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

bpftool: Add kernel.kptr_restrict hint for no instructions

Browse Source 
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 <vincent.mc.li@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://github.com/libbpf/bpftool/issues/184 [0]
Link: https://lore.kernel.org/bpf/20250818165113.15982-1-vincent.mc.li@gmail.com
This commit is contained in:
Vincent Li 2025-08-18 09:51:13 -07:00 committed by Daniel Borkmann
parent 5c42715e63
commit bf7a6a6705
1 changed files with 1 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
tools/bpf/bpftool/prog.c
View File

@ -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);