On 12/14/23 18:22, Martin KaFai Lau wrote:
On 12/8/23 4:26 PM, thinker.li@xxxxxxxxx wrote:
+const struct bpf_struct_ops_desc *btf_get_struct_ops(struct btf *btf,
u32 *ret_cnt)
+{
+ if (!btf)
+ return NULL;
+ if (!btf->struct_ops_tab)
*ret_cnt = 0;
unless the later patch checks the return value NULL before using *ret_cnt.
Anyway, better to set *ret_cnt to 0 if the btf has no struct_ops.
The same should go for the "!btf" case above but I suspect the above
!btf check is unnecessary also and the caller should have checked for
!btf itself instead of expecting a list of struct_ops from a NULL btf.
Lets continue the review on the later patches for now to confirm where
the above !btf case might happen.
Checking callers, I didn't find anything that make btf here NULL so far.
It is safe to remove !btf check. For the same reason as assigning
*ret_cnt for safe, this check should be fine here as well, right?
I don't have strong opinion here. What I though is to keep the values
as it is without any side-effect if the function call fails and if
possible. And, the callers should not expect the callee to set some
specific values when a call fails.
+ return NULL;
+
+ *ret_cnt = btf->struct_ops_tab->cnt;
+ return (const struct bpf_struct_ops_desc *)btf->struct_ops_tab->ops;
+}
