The addition of is_reg_const() in commit 171de12646d2 ("bpf: generalize
is_branch_taken to handle all conditional jumps in one place") has made the
register_is_const() redundent. Give the former has more feature, plus the
fact the latter is only used in one place, replace register_is_const() with
is_reg_const(), and remove the definition of register_is_const.
This requires moving the definition of is_reg_const() further up. And since
the comment of reg_const_value() reference is_reg_const(), move it up as
well.
Signed-off-by: Shung-Hsi Yu <shung-hsi.yu@xxxxxxxx>
---
kernel/bpf/verifier.c | 27 +++++++++++----------------
1 file changed, 11 insertions(+), 16 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 2197385d91dc..a7651a861e42 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -4685,9 +4685,17 @@ static bool register_is_null(struct bpf_reg_state *reg)
return reg->type == SCALAR_VALUE && tnum_equals_const(reg->var_off, 0);
}
-static bool register_is_const(struct bpf_reg_state *reg)
+/* check if register is a constant scalar value */
+static bool is_reg_const(struct bpf_reg_state *reg, bool subreg32)
{
- return reg->type == SCALAR_VALUE && tnum_is_const(reg->var_off);
+ return reg->type == SCALAR_VALUE &&
+ tnum_is_const(subreg32 ? tnum_subreg(reg->var_off) : reg->var_off);
+}
+
+/* assuming is_reg_const() is true, return constant value of a register */
+static u64 reg_const_value(struct bpf_reg_state *reg, bool subreg32)
+{
+ return subreg32 ? tnum_subreg(reg->var_off).value : reg->var_off.value;
}
static bool __is_scalar_unbounded(struct bpf_reg_state *reg)
@@ -10030,7 +10038,7 @@ record_func_key(struct bpf_verifier_env *env, struct bpf_call_arg_meta *meta,
val = reg->var_off.value;
max = map->max_entries;
- if (!(register_is_const(reg) && val < max)) {
+ if (!(is_reg_const(reg, false) && val < max)) {
bpf_map_key_store(aux, BPF_MAP_KEY_POISON);
return 0;
}
@@ -14167,19 +14175,6 @@ static void find_good_pkt_pointers(struct bpf_verifier_state *vstate,
}));
}
-/* check if register is a constant scalar value */
-static bool is_reg_const(struct bpf_reg_state *reg, bool subreg32)
-{
- return reg->type == SCALAR_VALUE &&
- tnum_is_const(subreg32 ? tnum_subreg(reg->var_off) : reg->var_off);
-}
-
-/* assuming is_reg_const() is true, return constant value of a register */
-static u64 reg_const_value(struct bpf_reg_state *reg, bool subreg32)
-{
- return subreg32 ? tnum_subreg(reg->var_off).value : reg->var_off.value;
-}
-
/*
* <reg1> <op> <reg2>, currently assuming reg2 is a constant
*/
base-commit: 856624f12b04a3f51094fa277a31a333ee81cb3f
--
2.42.0
