On Mon, 2024-08-12 at 11:26 -0700, Yonghong Song wrote:
[...]
>
> We could do the following to avoid double comparison: diff --git
> a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index
> df3be12096cf..1906798f1a3d 100644 --- a/kernel/bpf/verifier.c +++
> b/kernel/bpf/verifier.c @@ -17338,10 +17338,13 @@ static bool
> stacksafe(struct bpf_verifier_env *env, struct bpf_func_state *old, */
> for (i = 0; i < old->allocated_stack; i++) { struct bpf_reg_state
> *old_reg, *cur_reg; + bool cur_exceed_bound; spi = i / BPF_REG_SIZE; -
> if (exact != NOT_EXACT && + cur_exceed_bound = i >=
> cur->allocated_stack; + + if (exact != NOT_EXACT && !cur_exceed_bound &&
> old->stack[spi].slot_type[i % BPF_REG_SIZE] !=
> cur->stack[spi].slot_type[i % BPF_REG_SIZE]) return false; @@ -17363,7
> +17366,7 @@ static bool stacksafe(struct bpf_verifier_env *env, struct
> bpf_func_state *old, /* explored stack has more populated slots than
> current stack * and these slots were used */ - if (i >=
> cur->allocated_stack) + if (cur_exceed_bound) return false; /* 64-bit
> scalar spill vs all slots MISC and vice versa. WDYT?
>
Yonghong, something went wrong with formatting of the above email,
could you please resend?
