On Wed, Sep 15, 2021 at 11:06 AM Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> wrote: > > On Wed, Sep 15, 2021 at 09:48:35PM IST, Alexei Starovoitov wrote: > > On Wed, Sep 15, 2021 at 10:39:36AM +0530, Kumar Kartikeya Dwivedi wrote: > > > This adds helpers for registering btf_id_set from modules and the > > > check_kfunc_call callback that can be used to look them up. > > > > > > With in kernel sets, the way this is supposed to work is, in kernel > > > callback looks up within the in-kernel kfunc whitelist, and then defers > > > to the dynamic BTF set lookup if it doesn't find the BTF id. If there is > > > no in-kernel BTF id set, this callback can be used directly. > > > > > > Also fix includes for btf.h and bpfptr.h so that they can included in > > > isolation. This is in preparation for their usage in tcp_bbr, tcp_cubic > > > and tcp_dctcp modules in the next patch. > > > > > > Signed-off-by: Kumar Kartikeya Dwivedi <memxor@xxxxxxxxx> > > > --- > > > include/linux/bpfptr.h | 1 + > > > include/linux/btf.h | 32 ++++++++++++++++++++++++++ > > > kernel/bpf/btf.c | 51 ++++++++++++++++++++++++++++++++++++++++++ > > > 3 files changed, 84 insertions(+) > > > > > > diff --git a/include/linux/bpfptr.h b/include/linux/bpfptr.h > > > index 546e27fc6d46..46e1757d06a3 100644 > > > --- a/include/linux/bpfptr.h > > > +++ b/include/linux/bpfptr.h > > > @@ -3,6 +3,7 @@ > > > #ifndef _LINUX_BPFPTR_H > > > #define _LINUX_BPFPTR_H > > > > > > +#include <linux/mm.h> > > > > Could you explain what this is for? > > > > When e.g. tcp_bbr.c includes btf.h and btf_ids.h without this, it leads to this > error. > > from net/ipv4/tcp_bbr.c:59: > ./include/linux/bpfptr.h: In function ‘kvmemdup_bpfptr’: > ./include/linux/bpfptr.h:67:19: error: implicit declaration of function ‘kvmalloc’; > did you mean ‘kmalloc’? [-Werror=implicit-function-declaration] > 67 | void *p = kvmalloc(len, GFP_USER | __GFP_NOWARN); > | ^~~~~~~~ > | kmalloc > ./include/linux/bpfptr.h:67:19: warning: initialization of ‘void *’ from ‘int’ > makes pointer from integer without a cast [-Wint-conversion] > ./include/linux/bpfptr.h:72:17: error: implicit declaration of function ‘kvfree’; > did you mean ‘kfree’? [-Werror=implicit-function-declaration] > 72 | kvfree(p); > | ^~~~~~ > | kfree Interesting. It's because of kvmalloc in kvmemdup_bpfptr. Which is used in ___bpf_copy_key. Which is used in map_update_elem. And afair all maps enforce key_size < KMALLOC_MAX_SIZE. Not sure why kvmalloc was there. If it was kmalloc instead then #include <linux/slab.h> in linux/sockptr.h that is included by linux/bpfptr.h would have been enough. A food for thought.
