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| author | Jiong Wang <jiong.wang@netronome.com> | 2019-04-12 23:59:36 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2019-04-13 02:06:33 +0200 |
| commit | 55e7f3b5ac94a8c9f2e35961a45e9aa526a9e41d (patch) | |
| tree | e9cd98b8ca3044e8783ac98db6525b651e4a5192 /kernel/bpf | |
| parent | bpf: refactor propagate_liveness to eliminate code redundance (diff) | |
| download | linux-55e7f3b5ac94a8c9f2e35961a45e9aa526a9e41d.tar.xz linux-55e7f3b5ac94a8c9f2e35961a45e9aa526a9e41d.zip | |
bpf: factor out reg and stack slot propagation into "propagate_liveness_reg"
After code refactor in previous patches, the propagation logic inside the
for loop in "propagate_liveness" becomes clear that they are good enough to
be factored out into a common function "propagate_liveness_reg".
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'kernel/bpf')
| -rw-r--r-- | kernel/bpf/verifier.c | 30 |
1 files changed, 20 insertions, 10 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 6fd36a8ba1a0..3fdb301c4f8c 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -6221,6 +6221,22 @@ static bool states_equal(struct bpf_verifier_env *env, return true; } +static int propagate_liveness_reg(struct bpf_verifier_env *env, + struct bpf_reg_state *reg, + struct bpf_reg_state *parent_reg) +{ + int err; + + if (parent_reg->live & REG_LIVE_READ || !(reg->live & REG_LIVE_READ)) + return 0; + + err = mark_reg_read(env, reg, parent_reg); + if (err) + return err; + + return 0; +} + /* A write screens off any subsequent reads; but write marks come from the * straight-line code between a state and its parent. When we arrive at an * equivalent state (jump target or such) we didn't arrive by the straight-line @@ -6250,11 +6266,8 @@ static int propagate_liveness(struct bpf_verifier_env *env, state_reg = state->regs; /* We don't need to worry about FP liveness, it's read-only */ for (i = frame < vstate->curframe ? BPF_REG_6 : 0; i < BPF_REG_FP; i++) { - if (parent_reg[i].live & REG_LIVE_READ) - continue; - if (!(state_reg[i].live & REG_LIVE_READ)) - continue; - err = mark_reg_read(env, &state_reg[i], &parent_reg[i]); + err = propagate_liveness_reg(env, &state_reg[i], + &parent_reg[i]); if (err) return err; } @@ -6264,11 +6277,8 @@ static int propagate_liveness(struct bpf_verifier_env *env, i < parent->allocated_stack / BPF_REG_SIZE; i++) { parent_reg = &parent->stack[i].spilled_ptr; state_reg = &state->stack[i].spilled_ptr; - if (parent_reg->live & REG_LIVE_READ) - continue; - if (!(state_reg->live & REG_LIVE_READ)) - continue; - err = mark_reg_read(env, state_reg, parent_reg); + err = propagate_liveness_reg(env, state_reg, + parent_reg); if (err) return err; } |