Re: [PATCH v9 06/10] bpf: Add bpf_lookup_*_key() and bpf_key_put() kfuncs

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+noinline __weak struct bpf_key *bpf_lookup_user_key(u32 serial, u64 flags)

Why the need for noinline and the __weak here and below? (If indeed needed this should probably be explained in the commit desc.)

Oh, I took from v3 of KP's patch set. It is gone in v5. Will do the same as well.

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+{

• key_ref_t key_ref;
• struct bpf_key *bkey;
• /* Keep in sync with include/linux/key.h. */
• if (flags > (KEY_LOOKUP_PARTIAL << 1) - 1)

Can't we just simplify and test flags & ~(KEY_LOOKUP_CREATE|KEY_LOOKUP_PARTIAL)?

I thought as if we have many flags.

I'd keep it simple for now, and if the actual need comes this can still be changed.

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• return NULL;
  

• /* Permission check is deferred until actual kfunc using the key. */
• key_ref = lookup_user_key(serial, flags, KEY_DEFER_PERM_CHECK);
• if (IS_ERR(key_ref))

• return NULL;
  

• bkey = kmalloc(sizeof(*bkey), GFP_KERNEL);
• if (!bkey) {

• key_put(key_ref_to_ptr(key_ref));
  

• return bkey;
  

nit: just return NULL probably cleaner

Ok.