Re: [PATCH bpf-next v3 3/9] bpf: fetch the vmlinux BTF where kernel types enter a program

The scenario does not happen; v4 keeps this behaviour:
https://lore.kernel.org/bpf/20261001225214.12351-1-wanjay@amazon.com/ (local)

With CONFIG_DEBUG_INFO_BTF=m an allocation failure of the parse is not
stored: bpf_load_btf_vmlinux(), which parses the BTF in v4, returns the
error without publishing it, btf_vmlinux stays NULL, the next request
retries, and this check does not fire for anyone.  What v4 does store
with =m, as a later bpf-ci review asked, is a parse failure for any
other reason.  The payload was checked against the kernel's size and
SHA-256 when btf_vmlinux.ko loaded, so that means the build produced a
broken BTF.  The same happens with =y, where upstream already fails
every later bpf_check() with this message.

With =y the parse happens at boot, through the first vmlinux kfunc
registration, as it does today.

Jay