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Andrii Nakryiko 1bdb6c9a1c libbpf: Add a bunch of attribute getters/setters for map definitions
Add a bunch of getter for various aspects of BPF map. Some of these attribute
(e.g., key_size, value_size, type, etc) are available right now in struct
bpf_map_def, but this patch adds getter allowing to fetch them individually.
bpf_map_def approach isn't very scalable, when ABI stability requirements are
taken into account. It's much easier to extend libbpf and add support for new
features, when each aspect of BPF map has separate getter/setter.

Getters follow the common naming convention of not explicitly having "get" in
its name: bpf_map__type() returns map type, bpf_map__key_size() returns
key_size. Setters, though, explicitly have set in their name:
bpf_map__set_type(), bpf_map__set_key_size().

This patch ensures we now have a getter and a setter for the following
map attributes:
  - type;
  - max_entries;
  - map_flags;
  - numa_node;
  - key_size;
  - value_size;
  - ifindex.

bpf_map__resize() enforces unnecessary restriction of max_entries > 0. It is
unnecessary, because libbpf actually supports zero max_entries for some cases
(e.g., for PERF_EVENT_ARRAY map) and treats it specially during map creation
time. To allow setting max_entries=0, new bpf_map__set_max_entries() setter is
added. bpf_map__resize()'s behavior is preserved for backwards compatibility
reasons.

Map ifindex getter is added as well. There is a setter already, but no
corresponding getter. Fix this assymetry as well. bpf_map__set_ifindex()
itself is converted from void function into error-returning one, similar to
other setters. The only error returned right now is -EBUSY, if BPF map is
already loaded and has corresponding FD.

One lacking attribute with no ability to get/set or even specify it
declaratively is numa_node. This patch fixes this gap and both adds
programmatic getter/setter, as well as adds support for numa_node field in
BTF-defined map.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20200621062112.3006313-1-andriin@fb.com
2020-06-23 00:01:32 +02:00
arch flexible-array member conversion patches for 5.8-rc2 2020-06-16 17:23:57 -07:00
block block: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
certs
crypto Merge branch 'rwonce/rework' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux 2020-06-10 14:46:54 -07:00
Documentation Documentation: remove SH-5 index entries 2020-06-16 17:39:43 -07:00
drivers Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-06-16 17:44:54 -07:00
fs AFS fixes 2020-06-16 17:40:51 -07:00
include bpf: Support access to bpf map fields 2020-06-22 22:22:58 +02:00
init Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
ipc mmap locking API: use coccinelle to convert mmap_sem rwsem call sites 2020-06-09 09:39:14 -07:00
kernel bpf: Set map_btf_{name, id} for all map types 2020-06-22 22:22:58 +02:00
lib test_objagg: Fix potential memory leak in error handling 2020-06-15 13:32:11 -07:00
LICENSES
mm Kbuild updates for v5.8 (2nd) 2020-06-13 13:29:16 -07:00
net bpf: Set map_btf_{name, id} for all map types 2020-06-22 22:22:58 +02:00
samples samples: mei: Replace zero-length array with flexible-array 2020-06-15 23:08:31 -05:00
scripts scripts/decode_stacktrace: warn when modpath is needed but is unset 2020-06-15 15:37:24 -07:00
security ima: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
sound ASoC: SOF: Replace zero-length array with flexible-array 2020-06-15 23:08:32 -05:00
tools libbpf: Add a bunch of attribute getters/setters for map definitions 2020-06-23 00:01:32 +02:00
usr bpfilter: match bit size of bpfilter_umh to that of the kernel 2020-05-17 18:52:01 +09:00
virt MIPS: 2020-06-12 11:05:52 -07:00
.clang-format block: add bio_for_each_bvec_all() 2020-05-25 11:25:24 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore modpost: generate vmlinux.symvers and reuse it for the second modpost 2020-06-06 23:38:12 +09:00
.mailmap A fair amount of stuff this time around, dominated by yet another massive 2020-06-01 15:45:27 -07:00
COPYING
CREDITS mailmap: change email for Ricardo Ribalda 2020-05-25 18:59:59 -06:00
Kbuild
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS MAINTAINERS: switch to my private email for Renesas Ethernet drivers 2020-06-15 13:38:45 -07:00
Makefile Linux 5.8-rc1 2020-06-14 12:45:04 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.