From: Maxim Mikityanskiy maxim@isovalent.com
Extract the common code that generates a register ID for src_reg before MOV if needed into a new function. This function will also be used in a following commit.
Signed-off-by: Maxim Mikityanskiy maxim@isovalent.com --- kernel/bpf/verifier.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 89f8c527ed3c..a703e3adedd3 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4401,6 +4401,18 @@ static bool __is_pointer_value(bool allow_ptr_leaks, return reg->type != SCALAR_VALUE; }
+static void assign_scalar_id_before_mov(struct bpf_verifier_env *env, + struct bpf_reg_state *src_reg) +{ + if (src_reg->type == SCALAR_VALUE && !src_reg->id && + !tnum_is_const(src_reg->var_off)) + /* Ensure that src_reg has a valid ID that will be copied to + * dst_reg and then will be used by find_equal_scalars() to + * propagate min/max range. + */ + src_reg->id = ++env->id_gen; +} + /* Copy src state preserving dst->parent and dst->live fields */ static void copy_register_state(struct bpf_reg_state *dst, const struct bpf_reg_state *src) { @@ -13886,20 +13898,13 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) if (BPF_SRC(insn->code) == BPF_X) { struct bpf_reg_state *src_reg = regs + insn->src_reg; struct bpf_reg_state *dst_reg = regs + insn->dst_reg; - bool need_id = src_reg->type == SCALAR_VALUE && !src_reg->id && - !tnum_is_const(src_reg->var_off);
if (BPF_CLASS(insn->code) == BPF_ALU64) { if (insn->off == 0) { /* case: R1 = R2 * copy register state to dest reg */ - if (need_id) - /* Assign src and dst registers the same ID - * that will be used by find_equal_scalars() - * to propagate min/max range. - */ - src_reg->id = ++env->id_gen; + assign_scalar_id_before_mov(env, src_reg); copy_register_state(dst_reg, src_reg); dst_reg->live |= REG_LIVE_WRITTEN; dst_reg->subreg_def = DEF_NOT_SUBREG; @@ -13914,8 +13919,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) bool no_sext;
no_sext = src_reg->umax_value < (1ULL << (insn->off - 1)); - if (no_sext && need_id) - src_reg->id = ++env->id_gen; + if (no_sext) + assign_scalar_id_before_mov(env, src_reg); copy_register_state(dst_reg, src_reg); if (!no_sext) dst_reg->id = 0; @@ -13937,8 +13942,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) if (insn->off == 0) { bool is_src_reg_u32 = src_reg->umax_value <= U32_MAX;
- if (is_src_reg_u32 && need_id) - src_reg->id = ++env->id_gen; + if (is_src_reg_u32) + assign_scalar_id_before_mov(env, src_reg); copy_register_state(dst_reg, src_reg); /* Make sure ID is cleared if src_reg is not in u32 * range otherwise dst_reg min/max could be incorrectly @@ -13952,8 +13957,8 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) /* case: W1 = (s8, s16)W2 */ bool no_sext = src_reg->umax_value < (1ULL << (insn->off - 1));
- if (no_sext && need_id) - src_reg->id = ++env->id_gen; + if (no_sext) + assign_scalar_id_before_mov(env, src_reg); copy_register_state(dst_reg, src_reg); if (!no_sext) dst_reg->id = 0;