mirror of
https://github.com/torvalds/linux
synced 2024-09-06 18:01:05 +00:00
bpf: Add the assign_scalar_id_before_mov function
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> Acked-by: Eduard Zingerman <eddyz87@gmail.com> Link: https://lore.kernel.org/r/20240108205209.838365-7-maxtram95@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This commit is contained in:
parent
b827eee4c4
commit
8e0e074aaf
|
@ -4403,6 +4403,18 @@ 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)
|
||||
{
|
||||
|
@ -13905,20 +13917,13 @@ 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;
|
||||
|
@ -13933,8 +13938,8 @@ 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;
|
||||
|
@ -13956,8 +13961,8 @@ 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
|
||||
|
@ -13971,8 +13976,8 @@ 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;
|
||||
|
|
Loading…
Reference in a new issue