| Message ID | 1473966755-30106-8-git-send-email-jakub.kicinski@netronome.com |
|---|---|
| State | Superseded, archived |
| Delegated to: | David Miller |
| Headers | show |
On Thu, Sep 15, 2016 at 08:12:27PM +0100, Jakub Kicinski wrote: > When running as parser interpret BPF_LD | BPF_IMM | BPF_DW > instructions as loading CONST_IMM with the value stored > in imm. The verifier will continue not recognizing those > due to concerns about search space/program complexity > increase. > > Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> > --- > v3: > - limit to parsers. > --- > kernel/bpf/verifier.c | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index d93e78331b90..f5bed7cce08d 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -1766,9 +1766,19 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn) > if (err) > return err; > > - if (insn->src_reg == 0) > - /* generic move 64-bit immediate into a register */ > + if (insn->src_reg == 0) { > + /* generic move 64-bit immediate into a register, > + * only analyzer needs to collect the ld_imm value. > + */ > + u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; > + > + if (!env->analyzer_ops) > + return 0; the check makes sense. thanks. Acked-by: Alexei Starovoitov <ast@kernel.org>
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index d93e78331b90..f5bed7cce08d 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -1766,9 +1766,19 @@ static int check_ld_imm(struct bpf_verifier_env *env, struct bpf_insn *insn) if (err) return err; - if (insn->src_reg == 0) - /* generic move 64-bit immediate into a register */ + if (insn->src_reg == 0) { + /* generic move 64-bit immediate into a register, + * only analyzer needs to collect the ld_imm value. + */ + u64 imm = ((u64)(insn + 1)->imm << 32) | (u32)insn->imm; + + if (!env->analyzer_ops) + return 0; + + regs[insn->dst_reg].type = CONST_IMM; + regs[insn->dst_reg].imm = imm; return 0; + } /* replace_map_fd_with_map_ptr() should have caught bad ld_imm64 */ BUG_ON(insn->src_reg != BPF_PSEUDO_MAP_FD);
When running as parser interpret BPF_LD | BPF_IMM | BPF_DW instructions as loading CONST_IMM with the value stored in imm. The verifier will continue not recognizing those due to concerns about search space/program complexity increase. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> --- v3: - limit to parsers. --- kernel/bpf/verifier.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-)