From: Maxim Mikityanskiy maxim@isovalent.com
Put calculation of the register value width into a dedicated function. This function will also be used in a following commit.
Signed-off-by: Maxim Mikityanskiy maxim@isovalent.com --- kernel/bpf/verifier.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index e3eff2becd64..4cd82a7c1318 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -4450,6 +4450,11 @@ static bool is_bpf_st_mem(struct bpf_insn *insn) return BPF_CLASS(insn->code) == BPF_ST && BPF_MODE(insn->code) == BPF_MEM; }
+static int get_reg_width(struct bpf_reg_state *reg) +{ + return fls64(reg->umax_value); +} + /* check_stack_{read,write}_fixed_off functions track spill/fill of registers, * stack boundary and alignment are checked in check_mem_access() */ @@ -4502,7 +4507,7 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env, if (reg && !(off % BPF_REG_SIZE) && register_is_bounded(reg) && env->bpf_capable) { save_register_state(env, state, spi, reg, size); /* Break the relation on a narrowing spill. */ - if (fls64(reg->umax_value) > BITS_PER_BYTE * size) + if (get_reg_width(reg) > BITS_PER_BYTE * size) state->stack[spi].spilled_ptr.id = 0; } else if (!reg && !(off % BPF_REG_SIZE) && is_bpf_st_mem(insn) && insn->imm != 0 && env->bpf_capable) { @@ -13955,7 +13960,7 @@ static int check_alu_op(struct bpf_verifier_env *env, struct bpf_insn *insn) return -EACCES; } else if (src_reg->type == SCALAR_VALUE) { if (insn->off == 0) { - bool is_src_reg_u32 = src_reg->umax_value <= U32_MAX; + bool is_src_reg_u32 = get_reg_width(src_reg) <= 32;
if (is_src_reg_u32) assign_scalar_id_before_mov(env, src_reg);