On Tue, Dec 3, 2024 at 5:49 AM Anton Protopopov <aspsk@xxxxxxxxxxxxx> wrote: > > The bpf_remove_insns() function returns WARN_ON_ONCE(error), where > error is a result of bpf_adj_branches(), and thus should be always 0 > However, if for any reason it is not 0, then it will be converted to > boolean by WARN_ON_ONCE and returned to user space as 1, not an actual > error value. Fix this by returning the original err after the WARN check. > > Signed-off-by: Anton Protopopov <aspsk@xxxxxxxxxxxxx> > Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> > --- > kernel/bpf/core.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) > Looks irrelevant to the patch set and probably should go through the bpf tree? I'll leave it up to Alexei to decide, though. Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx> > diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c > index a2327c4fdc8b..8b9711e6da6c 100644 > --- a/kernel/bpf/core.c > +++ b/kernel/bpf/core.c > @@ -539,6 +539,8 @@ struct bpf_prog *bpf_patch_insn_single(struct bpf_prog *prog, u32 off, > > int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) > { > + int err; > + > /* Branch offsets can't overflow when program is shrinking, no need > * to call bpf_adj_branches(..., true) here > */ > @@ -546,7 +548,9 @@ int bpf_remove_insns(struct bpf_prog *prog, u32 off, u32 cnt) > sizeof(struct bpf_insn) * (prog->len - off - cnt)); > prog->len -= cnt; > > - return WARN_ON_ONCE(bpf_adj_branches(prog, off, off + cnt, off, false)); > + err = bpf_adj_branches(prog, off, off + cnt, off, false); > + WARN_ON_ONCE(err); > + return err; > } > > static void bpf_prog_kallsyms_del_subprogs(struct bpf_prog *fp) > -- > 2.34.1 > >