linux/include/uapi
Alan Maguire f7a6b9eaff bpf: Extend BTF UAPI vlen, kinds to use unused bits
BTF maximum vlen is encoded using 16 bits with a maximum vlen
of 65535.  This has sufficed for structs, function parameters
and enumerated type values.  However, with upcoming BTF location
information - in particular information about inline sites -
this limit is surpassed.  Use bits 16-23 - currently unused in
BTF info - to extend to 24 bits, giving a max vlen of (2^24 - 1),
or 16 million.

Also extend BTF kind encoding from 5 to 7 bits, giving a maximum
available number of kinds of 128.  Since with the BTF location work
we use another 3 kinds, we are fast approaching the current limit
of 32.

Convert BTF_MAX_* values to enums to allow them to be encoded in
kernel BTF; this will allow us to detect if the running kernel
supports a 24-bit vlen or not.  Add one for max _possible_
(not used) kind.

Fix up a few places in the kernel where a 16-bit vlen is assumed;
remove BTF_INFO_MASK as now all bits are used.

The vlen expansion was suggested by Andrii in [1]; the kind expansion
is tackled here too as it may be needed also to support new kinds
in BTF.

[1] https://lore.kernel.org/bpf/CAEf4BzZx=X6vGqcA8SPU6D+v6k+TR=ZewebXMuXtpmML058piw@mail.gmail.com/

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
Link: https://lore.kernel.org/r/20260417143023.1551481-2-alan.maguire@oracle.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-04-20 17:52:48 -07:00
..
asm-generic Scheduler changes for v7.0: 2026-02-10 12:50:10 -08:00
cxl
drm Merge tag 'drm-msm-next-2026-04-02' of https://gitlab.freedesktop.org/drm/msm into drm-next 2026-04-03 18:57:00 +10:00
fwctl fwctl/bnxt_fwctl: Add bnxt fwctl device 2026-03-31 13:33:54 -03:00
linux bpf: Extend BTF UAPI vlen, kinds to use unused bits 2026-04-20 17:52:48 -07:00
misc Char/Misc/IIO/Binder changes for 6.18-rc1 2025-10-04 16:26:32 -07:00
mtd
rdma RDMA v7.0 merge window 2026-02-12 17:05:20 -08:00
regulator regulator: uapi: Use UAPI integer type 2025-12-22 09:00:42 +00:00
scsi scsi: ufs: core: Improve the documentation of UFS data frames 2026-01-11 22:04:10 -05:00
sound ASoC: SOF: ipc4-topology: Add new tokens for pipeline direction 2026-02-04 13:26:05 +00:00
video
xen
Kbuild