[PATCH v2 bpf-next 1/3] bpf: cleanup explored_states

[Alexei Starovoitov]

clean up explored_states to prep for introduction of hashtable
No functional changes.

Signed-off-by: Alexei Starovoitov <a...@kernel.org>
---
 kernel/bpf/verifier.c | 29 ++++++++++++++++++++---------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 95f9354495ad..f8a540b29c12 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -5436,6 +5436,17 @@ enum {
 };
 
 #define STATE_LIST_MARK ((struct bpf_verifier_state_list *) -1L)
+static struct bpf_verifier_state_list **explored_state(
+                                       struct bpf_verifier_env *env,
+                                       int idx)
+{
+       return &env->explored_states[idx];
+}
+
+static void init_explored_state(struct bpf_verifier_env *env, int idx)
+{
+       env->explored_states[idx] = STATE_LIST_MARK;
+}
 
 /* t, w, e - match pseudo-code above:
  * t - index of current instruction
@@ -5461,7 +5472,7 @@ static int push_insn(int t, int w, int e, struct 
bpf_verifier_env *env)
 
        if (e == BRANCH)
                /* mark branch target for state pruning */
-               env->explored_states[w] = STATE_LIST_MARK;
+               init_explored_state(env, w);
 
        if (insn_state[w] == 0) {
                /* tree-edge */
@@ -5529,9 +5540,9 @@ static int check_cfg(struct bpf_verifier_env *env)
                        else if (ret < 0)
                                goto err_free;
                        if (t + 1 < insn_cnt)
-                               env->explored_states[t + 1] = STATE_LIST_MARK;
+                               init_explored_state(env, t + 1);
                        if (insns[t].src_reg == BPF_PSEUDO_CALL) {
-                               env->explored_states[t] = STATE_LIST_MARK;
+                               init_explored_state(env, t);
                                ret = push_insn(t, t + insns[t].imm + 1, 
BRANCH, env);
                                if (ret == 1)
                                        goto peek_stack;
@@ -5554,10 +5565,10 @@ static int check_cfg(struct bpf_verifier_env *env)
                         * after every call and jump
                         */
                        if (t + 1 < insn_cnt)
-                               env->explored_states[t + 1] = STATE_LIST_MARK;
+                               init_explored_state(env, t + 1);
                } else {
                        /* conditional jump with two edges */
-                       env->explored_states[t] = STATE_LIST_MARK;
+                       init_explored_state(env, t);
                        ret = push_insn(t, t + 1, FALLTHROUGH, env);
                        if (ret == 1)
                                goto peek_stack;
@@ -6005,7 +6016,7 @@ static void clean_live_states(struct bpf_verifier_env 
*env, int insn,
        struct bpf_verifier_state_list *sl;
        int i;
 
-       sl = env->explored_states[insn];
+       sl = *explored_state(env, insn);
        if (!sl)
                return;
 
@@ -6364,7 +6375,7 @@ static int is_state_visited(struct bpf_verifier_env *env, 
int insn_idx)
        struct bpf_verifier_state *cur = env->cur_state, *new;
        int i, j, err, states_cnt = 0;
 
-       pprev = &env->explored_states[insn_idx];
+       pprev = explored_state(env, insn_idx);
        sl = *pprev;
 
        if (!sl)
@@ -6451,8 +6462,8 @@ static int is_state_visited(struct bpf_verifier_env *env, 
int insn_idx)
                kfree(new_sl);
                return err;
        }
-       new_sl->next = env->explored_states[insn_idx];
-       env->explored_states[insn_idx] = new_sl;
+       new_sl->next = *explored_state(env, insn_idx);
+       *explored_state(env, insn_idx) = new_sl;
        /* connect new state to parentage chain. Current frame needs all
         * registers connected. Only r6 - r9 of the callers are alive (pushed
         * to the stack implicitly by JITs) so in callers' frames connect just
-- 
2.20.0