Daniel Borkmann says:

====================
pull-request: bpf-next 2020-12-14

1) Expose bpf_sk_storage_*() helpers to iterator programs, from Florent Revest.

2) Add AF_XDP selftests based on veth devs to BPF selftests, from Weqaar Janjua.

3) Support for finding BTF based kernel attach targets through libbpf's
   bpf_program__set_attach_target() API, from Andrii Nakryiko.

4) Permit pointers on stack for helper calls in the verifier, from Yonghong Song.

5) Fix overflows in hash map elem size after rlimit removal, from Eric Dumazet.

6) Get rid of direct invocation of llc in BPF selftests, from Andrew Delgadillo.

7) Fix xsk_recvmsg() to reorder socket state check before access, from Björn Töpel.

8) Add new libbpf API helper to retrieve ring buffer epoll fd, from Brendan Jackman.

9) Batch of minor BPF selftest improvements all over the place, from Florian Lehner,
   KP Singh, Jiri Olsa and various others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (31 commits)
  selftests/bpf: Add a test for ptr_to_map_value on stack for helper access
  bpf: Permits pointers on stack for helper calls
  libbpf: Expose libbpf ring_buffer epoll_fd
  selftests/bpf: Add set_attach_target() API selftest for module target
  libbpf: Support modules in bpf_program__set_attach_target() API
  selftests/bpf: Silence ima_setup.sh when not running in verbose mode.
  selftests/bpf: Drop the need for LLVM's llc
  selftests/bpf: fix bpf_testmod.ko recompilation logic
  samples/bpf: Fix possible hang in xdpsock with multiple threads
  selftests/bpf: Make selftest compilation work on clang 11
  selftests/bpf: Xsk selftests - adding xdpxceiver to .gitignore
  selftests/bpf: Drop tcp-{client,server}.py from Makefile
  selftests/bpf: Xsk selftests - Bi-directional Sockets - SKB, DRV
  selftests/bpf: Xsk selftests - Socket Teardown - SKB, DRV
  selftests/bpf: Xsk selftests - DRV POLL, NOPOLL
  selftests/bpf: Xsk selftests - SKB POLL, NOPOLL
  selftests/bpf: Xsk selftests framework
  bpf: Only provide bpf_sock_from_file with CONFIG_NET
  bpf: Return -ENOTSUPP when attaching to non-kernel BTF
  xsk: Validate socket state in xsk_recvmsg, prior touching socket members
  ...
====================

Link: https://lore.kernel.org/r/20201214214316.20642-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

xdp_return_frame_bulk() needs to pass a xdp_buff
to __xdp_return().

strlcpy got converted to strscpy but here it makes no
functional difference, so just keep the right code.

Conflicts:
	net/netfilter/nf_tables_api.c

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Remove bpf_ prefix, which causes these helpers to be reported in verifier
dump as bpf_bpf_this_cpu_ptr() and bpf_bpf_per_cpu_ptr(), respectively. Lets
fix it as long as it is still possible before UAPI freezes on these helpers.

Fixes: eaa6bcb71ef6 ("bpf: Introduce bpf_per_cpu_ptr()")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

While eBPF programs can check whether a file is a socket by file->f_op
== &socket_file_ops, they cannot convert the void private_data pointer
to a struct socket BTF pointer. In order to do this a new helper
wrapping sock_from_file is added.

This is useful to tracing programs but also other program types
inheriting this set of helpers such as iterators or LSM programs.

Signed-off-by: Florent Revest <revest@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: KP Singh <kpsingh@google.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201204113609.1850150-2-revest@google.com

Add ability for user-space programs to specify non-vmlinux BTF when attaching
BTF-powered BPF programs: raw_tp, fentry/fexit/fmod_ret, LSM, etc. For this,
attach_prog_fd (now with the alias name attach_btf_obj_fd) should specify FD
of a module or vmlinux BTF object. For backwards compatibility reasons,
0 denotes vmlinux BTF. Only kernel BTF (vmlinux or module) can be specified.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20201203204634.1325171-11-andrii@kernel.org

Provide a wrapper function to get the IMA hash of an inode. This helper
is useful in fingerprinting files (e.g executables on execution) and
using these fingerprints in detections like an executable unlinking
itself.

Since the ima_inode_hash can sleep, it's only allowed for sleepable
LSM hooks.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20201124151210.1081188-3-kpsingh@chromium.org

The helper uses CLOCK_MONOTONIC_COARSE source of time that is less
accurate but more performant.

We have a BPF CGROUP_SKB firewall that supports event logging through
bpf_perf_event_output(). Each event has a timestamp and currently we use
bpf_ktime_get_ns() for it. Use of bpf_ktime_get_coarse_ns() saves ~15-20
ns in time required for event logging.

bpf_ktime_get_ns():
EgressLogByRemoteEndpoint                              113.82ns    8.79M

bpf_ktime_get_coarse_ns():
EgressLogByRemoteEndpoint                               95.40ns   10.48M

Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201117184549.257280-1-me@ubique.spb.ru

The helper allows modification of certain bits on the linux_binprm
struct starting with the secureexec bit which can be updated using the
BPF_F_BPRM_SECUREEXEC flag.

secureexec can be set by the LSM for privilege gaining executions to set
the AT_SECURE auxv for glibc.  When set, the dynamic linker disables the
use of certain environment variables (like LD_PRELOAD).

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201117232929.2156341-1-kpsingh@chromium.org

Allocate ID for vmlinux BTF. This makes it visible when iterating over all BTF
objects in the system. To allow distinguishing vmlinux BTF (and later kernel
module BTF) from user-provided BTFs, expose extra kernel_btf flag, as well as
BTF name ("vmlinux" for vmlinux BTF, will equal to module's name for module
BTF).  We might want to later allow specifying BTF name for user-provided BTFs
as well, if that makes sense. But currently this is reserved only for
in-kernel BTFs.

Having in-kernel BTFs exposed IDs will allow to extend BPF APIs that require
in-kernel BTF type with ability to specify BTF types from kernel modules, not
just vmlinux BTF. This will be implemented in a follow up patch set for
fentry/fexit/fmod_ret/lsm/etc.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201110011932.3201430-3-andrii@kernel.org

The currently available bpf_get_current_task returns an unsigned integer
which can be used along with BPF_CORE_READ to read data from
the task_struct but still cannot be used as an input argument to a
helper that accepts an ARG_PTR_TO_BTF_ID of type task_struct.

In order to implement this helper a new return type, RET_PTR_TO_BTF_ID,
is added. This is similar to RET_PTR_TO_BTF_ID_OR_NULL but does not
require checking the nullness of returned pointer.

Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201106103747.2780972-6-kpsingh@chromium.org