This patch add a xdp program on egress to show that we can modify
the packet on egress. In this sample we will set the pkt's src
mac to egress's mac address. The xdp_prog will be attached when
-X option supplied.

Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/20210122025007.2968381-1-liuhangbin@gmail.com

The current LLVM and Clang build procedure in samples/bpf/README.rst is
out of date. See below that the links are not accessible any more.

  $ git clone http://llvm.org/git/llvm.git
  Cloning into 'llvm'...
  fatal: unable to access 'http://llvm.org/git/llvm.git/': Maximum (20) redirects followed
  $ git clone --depth 1 http://llvm.org/git/clang.git
  Cloning into 'clang'...
  fatal: unable to access 'http://llvm.org/git/clang.git/': Maximum (20) redirects followed

The LLVM community has adopted new ways to build the compiler. There are
different ways to build LLVM and Clang, the Clang Getting Started page [1]
has one way. As Yonghong said, it is better to copy the build procedure
in Documentation/bpf/bpf_devel_QA.rst to keep consistent.

I verified the procedure and it is proved to be feasible, so we should
update README.rst to reflect the reality. At the same time, update the
related comment in Makefile.

Additionally, as Fangrui said, the dir llvm-project/llvm/build/install is
not used, BUILD_SHARED_LIBS=OFF is the default option [2], so also change
Documentation/bpf/bpf_devel_QA.rst together.

At last, we recommend that developers who want the fastest incremental
builds use the Ninja build system [1], you can find it in your system's
package manager, usually the package is ninja or ninja-build [3], so add
ninja to build dependencies suggested by Nathan.

  [1] https://clang.llvm.org/get_started.html
  [2] https://www.llvm.org/docs/CMake.html
  [3] https://github.com/ninja-build/ninja/wiki/Pre-built-Ninja-packages



Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Cc: Fangrui Song <maskray@google.com>
Link: https://lore.kernel.org/bpf/1611279584-26047-1-git-send-email-yangtiezhu@loongson.cn

Brendan Jackman added extend atomic operations to the BPF instruction
set in commit 7064a734 ("Merge branch 'Atomics for eBPF'"), which
introduces the BPF_ATOMIC_OP macro. However, that macro was missing
for the BPF samples. Fix that by adding it into bpf_insn.h.

Fixes: 91c960b0 ("bpf: Rename BPF_XADD and prepare to encode other atomics in .imm")
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Brendan Jackman <jackmanb@google.com>
Link: https://lore.kernel.org/bpf/20210118091753.107572-1-bjorn.topel@gmail.com


Signed-off-by: Alexei Starovoitov <ast@kernel.org>

A subsequent patch will add additional atomic operations. These new
operations will use the same opcode field as the existing XADD, with
the immediate discriminating different operations.

In preparation, rename the instruction mode BPF_ATOMIC and start
calling the zero immediate BPF_ADD.

This is possible (doesn't break existing valid BPF progs) because the
immediate field is currently reserved MBZ and BPF_ADD is zero.

All uses are removed from the tree but the BPF_XADD definition is
kept around to avoid breaking builds for people including kernel
headers.

Signed-off-by: Brendan Jackman <jackmanb@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@gmail.com>
Link: https://lore.kernel.org/bpf/20210114181751.768687-5-jackmanb@google.com

Fix a possible hang in xdpsock that can occur when using multiple
threads. In this case, one or more of the threads might get stuck in
the while-loop in tx_only after the user has signaled the main thread
to stop execution. In this case, no more Tx packets will be sent, so a
thread might get stuck in the aforementioned while-loop. Fix this by
introducing a test inside the while-loop to check if the benchmark has
been terminated. If so, return from the function.

Fixes: cd9e72b6 ("samples/bpf: xdpsock: Add option to specify batch size")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20201210163407.22066-1-magnus.karlsson@gmail.com

There is a spelling mistake in an error message. Fix it.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Link: https://lore.kernel.org/bpf/20201203114452.1060017-1-colin.king@canonical.com

Introduce a sample program to demonstrate the control and data
plane split. For the control plane part a new program called
xdpsock_ctrl_proc is introduced. For the data plane part, some code
was added to xdpsock_user.c to act as the data plane entity.

Application xdpsock_ctrl_proc works as control entity with sudo
privileges (CAP_SYS_ADMIN and CAP_NET_ADMIN are sufficient) and the
extended xdpsock as data plane entity with CAP_NET_RAW capability
only.

Usage example:

sudo ./samples/bpf/xdpsock_ctrl_proc -i <interface>

sudo ./samples/bpf/xdpsock -i <interface> -q <queue_id>
	-n <interval> -N -l -R

Signed-off-by: Mariusz Dudek <mariuszx.dudek@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20201203090546.11976-3-mariuszx.dudek@intel.com

Since bpf is not using rlimit memlock for the memory accounting
and control, do not change the limit in sample applications.

Signed-off-by: Roman Gushchin <guro@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20201201215900.3569844-35-guro@fb.com

my_tramp[12]? are declared as global functions in C, but they are not
marked global in the inline assembly definition. This mismatch confuses
Clang's Control-Flow Integrity checking. Fix the definitions by adding
.globl.

Link: https://lkml.kernel.org/r/20201113183414.1446671-1-samitolvanen@google.com



Fixes: 9d907f1a ("ftrace/samples: Add a sample module that implements modify_ftrace_direct()")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Support for the SO_BUSY_POLL_BUDGET setsockopt, via the batching
option ('b').

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-11-bjorn.topel@gmail.com

Add a new option to xdpsock, 'B', for busy-polling. This option will
also set the batching size, 'b' option, to the busy-poll budget.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-10-bjorn.topel@gmail.com

Start using recvfrom() the l2fwd scenario, instead of poll() which is
more expensive and need additional knobs for busy-polling.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-9-bjorn.topel@gmail.com

Start using recvfrom() the rxdrop scenario.

Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20201130185205.196029-8-bjorn.topel@gmail.com

Currently the hidraw module can only read and write feature HID reports on
demand, via dedicated ioctls. Input reports are read from the device through
the read() interface, while output reports are written through the write
interface().

This is insufficient; it is desirable in many situations to be able to read and
write input and output reports through the control interface to cover
additional scenarios:

  - Reading an input report by its report ID, to get initial state
  - Writing an input report, to set initial input state in the device
  - Reading an output report by its report ID, to obtain current state
  - Writing an output report by its report ID, out of band

This patch adds these missing ioctl requests to read and write the remaining
HID report types. Note that not all HID backends will neccesarily support this
(e.g. while the USB link layer supports setting Input reports, others may not).

Also included are documentation and example updates. The current hidraw
documentation states that feature reports read from the device does *not*
include the report ID, however this is not the case and the returned report
will have its report ID prepended by conforming HID devices, as the report data
sent from the device over the control endpoint must be indentical in format to
those sent over the regular transport.

Signed-off-by: Dean Camera <dean@fourwalledcubicle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

Numerous refactoring that rewrites BPF programs written with bpf_load
to use the libbpf loader was finally completed, resulting in BPF
programs using bpf_load within the kernel being completely no longer
present.

This commit removes bpf_load, an outdated bpf loader that is difficult
to keep up with the latest kernel BPF and causes confusion.

Also, this commit removes the unused trace_helper and bpf_load from
samples/bpf target objects from Makefile.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201124090310.24374-8-danieltimlee@gmail.com

Currently, lwt_len_hist's map lwt_len_hist_map is uses pinning, and the
map isn't cleared on test end. This leds to reuse of that map for
each test, which prevents the results of the test from being accurate.

This commit fixes the problem by removing of pinned map from bpffs.
Also, this commit add the executable permission to shell script
files.

Fixes: f74599f7 ("bpf: Add tests and samples for LWT-BPF")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201124090310.24374-7-danieltimlee@gmail.com

This commit refactors the existing program with libbpf bpf loader.
Since the kprobe, tracepoint and raw_tracepoint bpf program can be
attached with single bpf_program__attach() interface, so the
corresponding function of libbpf is used here.

Rather than specifying the number of cpus inside the code, this commit
uses the number of available cpus with _SC_NPROCESSORS_ONLN.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201124090310.24374-6-danieltimlee@gmail.com

This commit refactors the existing ibumad program with libbpf bpf
loader. Attach/detach of Tracepoint bpf programs has been managed
with the generic bpf_program__attach() and bpf_link__destroy() from
the libbpf.

Also, instead of using the previous BPF MAP definition, this commit
refactors ibumad MAP definition with the new BTF-defined MAP format.

To verify that this bpf program works without an infiniband device,
try loading ib_umad kernel module and test the program as follows:

    # modprobe ib_umad
    # ./ibumad

Moreover, TRACE_HELPERS has been removed from the Makefile since it is
not used on this program.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201124090310.24374-5-danieltimlee@gmail.com

This commit refactors the existing kprobe program with libbpf bpf
loader. To attach bpf program, this uses generic bpf_program__attach()
approach rather than using bpf_load's load_bpf_file().

To attach bpf to perf_event, instead of using previous ioctl method,
this commit uses bpf_program__attach_perf_event since it manages the
enable of perf_event and attach of BPF programs to it, which is much
more intuitive way to achieve.

Also, explicit close(fd) has been removed since event will be closed
inside bpf_link__destroy() automatically.

Furthermore, to prevent conflict of same named uprobe events, O_TRUNC
flag has been used to clear 'uprobe_events' interface.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201124090310.24374-4-danieltimlee@gmail.com

This commit refactors the existing cgroup program with libbpf bpf
loader. The original test_cgrp2_sock2 has keeped the bpf program
attached to the cgroup hierarchy even after the exit of user program.
To implement the same functionality with libbpf, this commit uses the
BPF_LINK_PINNING to pin the link attachment even after it is closed.

Since this uses LINK instead of ATTACH, detach of bpf program from
cgroup with 'test_cgrp2_sock' is not used anymore.

The code to mount the bpf was added to the .sh file in case the bpff
was not mounted on /sys/fs/bpf. Additionally, to fix the problem that
shell script cannot find the binary object from the current path,
relative path './' has been added in front of binary.

Fixes: 554ae6e7 ("samples/bpf: add userspace example for prohibiting sockets")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201124090310.24374-3-danieltimlee@gmail.com

This commit refactors the existing cgroup programs with libbpf
bpf loader. Since bpf_program__attach doesn't support cgroup program
attachment, this explicitly attaches cgroup bpf program with
bpf_program__attach_cgroup(bpf_prog, cg1).

Also, to change attach_type of bpf program, this uses libbpf's
bpf_program__set_expected_attach_type helper to switch EGRESS to
INGRESS. To keep bpf program attached to the cgroup hierarchy even
after the exit, this commit uses the BPF_LINK_PINNING to pin the link
attachment even after it is closed.

Besides, this program was broken due to the typo of BPF MAP definition.
But this commit solves the problem by fixing this from 'queue_stats' map
struct hvm_queue_stats -> hbm_queue_stats.

Fixes: 36b5d471 ("selftests/bpf: samples/bpf: Split off legacy stuff from bpf_helpers.h")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201124090310.24374-2-danieltimlee@gmail.com

The only usage of qmi_sample_handlers[] and lookup_ops is to pass their
addresses to qmi_handle_init() which accepts const pointers to both
qmi_ops and qmi_msg_handler. Make them const to allow the compiler to
put them in read-only memory.

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20201124212954.17750-1-rikard.falkeborn@gmail.com


Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>

Increment the statistics over how many Tx packets have been sent at
the time of sending instead of at the time of completion. This as a
completion event means that the buffer has been sent AND returned to
user space. The packet always gets sent shortly after sendto() is
called. The kernel might, for performance reasons, decide to not
return every single buffer to user space immediately after sending,
for example, only after a batch of packets have been
transmitted. Incrementing the number of packets sent at completion,
will in that case be confusing as if you send a single packet, the
counter might show zero for a while even though the packet has been
transmitted.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/1605525167-14450-2-git-send-email-magnus.karlsson@gmail.com

The tcbpf2_kern.o and related kernel sections are moved to bpf
selftest folder since b05cd740 ("samples/bpf: remove the bpf tunnel
testsuite."). Remove this one as well.

Fixes: b05cd740 ("samples/bpf: remove the bpf tunnel testsuite.")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20201110015013.1570716-3-liuhangbin@gmail.com

The 'bpf/bpf.h' include in 'samples/bpf/hbm.c' is duplicated.

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/1604654034-52821-1-git-send-email-dong.menglong@zte.com.cn

This patch removes the MIC drivers from the kernel tree
since the corresponding devices have been discontinued.

Removing the dma and char-misc changes in one patch and
merging via the char-misc tree is best to avoid any
potential build breakage.

Cc: Nikhil Rao <nikhil.rao@intel.com>
Reviewed-by: Ashutosh Dixit <ashutosh.dixit@intel.com>
Signed-off-by: Sudeep Dutt <sudeep.dutt@intel.com>
Acked-By: Vinod Koul <vkoul@kernel.org>
Reviewed-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/8c1443136563de34699d2c084df478181c205db4.1603854416.git.sudeep.dutt@intel.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

The memlock rlimit is a notorious source of failure for BPF programs. Most
of the samples just set it to infinity, but a few used a lower limit. The
problem with unconditionally setting a lower limit is that this will also
override the limit if the system-wide setting is *higher* than the limit
being set, which can lead to failures on systems that lock a lot of memory,
but set 'ulimit -l' to unlimited before running a sample.

One fix for this is to only conditionally set the limit if the current
limit is lower, but it is simpler to just unify all the samples and have
them all set the limit to infinity.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/20201026233623.91728-1-toke@redhat.com

Yaniv reported a compilation error after pulling latest libbpf:

  [...]
  ../libbpf/src/root/usr/include/bpf/bpf_helpers.h:99:10: error:
  unknown register name 'r0' in asm
                     : "r0", "r1", "r2", "r3", "r4", "r5");
  [...]

The issue got triggered given Yaniv was compiling tracing programs with native
target (e.g. x86) instead of BPF target, hence no BTF generated vmlinux.h nor
CO-RE used, and later llc with -march=bpf was invoked to compile from LLVM IR
to BPF object file. Given that clang was expecting x86 inline asm and not BPF
one the error complained that these regs don't exist on the former.

Guard bpf_tail_call_static() with defined(__bpf__) where BPF inline asm is valid
to use. BPF tracing programs on more modern kernels use BPF target anyway and
thus the bpf_tail_call_static() function will be available for them. BPF inline
asm is supported since clang 7 (clang <= 6 otherwise throws same above error),
and __bpf_unreachable() since clang 8, therefore include the latter condition
in order to prevent compilation errors for older clang versions. Given even an
old Ubuntu 18.04 LTS has official LLVM packages all the way up to llvm-10, I did
not bother to special case the __bpf_unreachable() inside bpf_tail_call_static()
further.

Also, undo the sockex3_kern's use of bpf_tail_call_static() sample given they
still have the old hacky way to even compile networking progs with native instead
of BPF target so bpf_tail_call_static() won't be defined there anymore.

Fixes: 0e9f6841 ("bpf, libbpf: Add bpf_tail_call_static helper for bpf programs")
Reported-by: Yaniv Agman <yanivagman@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Tested-by: Yaniv Agman <yanivagman@gmail.com>
Link: https://lore.kernel.org/bpf/CAMy7=ZUk08w5Gc2Z-EKi4JFtuUCaZYmE4yzhJjrExXpYKR4L8w@mail.gmail.com
Link: https://lore.kernel.org/bpf/20201021203257.26223-1-daniel@iogearbox.net

kmemleak-test.c is just a kmemleak test module, which also can not be used
as a built-in kernel module.  Thus, i think it may should not be in mm
dir, and move the kmemleak-test.c to samples/kmemleak/kmemleak-test.c.
Fix the spelling of built-in by the way.

Signed-off-by: Hui Su <sh_def@163.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Rob Herring <robh@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Miguel Ojeda <miguel.ojeda.sandonis@gmail.com>
Cc: Divya Indi <divya.indi@oracle.com>
Cc: Tomas Winkler <tomas.winkler@intel.com>
Cc: David Howells <dhowells@redhat.com>
Link: https://lkml.kernel.org/r/20200925183729.GA172837@rlk


Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Most of the samples were converted to use the new BTF-defined MAP as
they moved to libbpf, but some of the samples were missing.

Instead of using the previous BPF MAP definition, this commit refactors
xdp_monitor and xdp_sample_pkts_kern MAP definition with the new
BTF-defined MAP format.

Also, this commit removes the max_entries attribute at PERF_EVENT_ARRAY
map type. The libbpf's bpf_object__create_map() will automatically
set max_entries to the maximum configured number of CPUs on the host.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201010181734.1109-4-danieltimlee@gmail.com

>From commit d7a18ea7 ("libbpf: Add generic bpf_program__attach()"),
for some BPF programs, it is now possible to attach BPF programs
with __attach() instead of explicitly calling __attach_<type>().

This commit refactors the __attach_tracepoint() with libbpf's generic
__attach() method. In addition, this refactors the logic of setting
the map FD to simplify the code. Also, the missing removal of
bpf_load.o in Makefile has been fixed.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201010181734.1109-3-danieltimlee@gmail.com

To avoid confusion caused by the increasing fragmentation of the BPF
Loader program, this commit would like to change to the libbpf loader
instead of using the bpf_load.

Thanks to libbpf's bpf_link interface, managing the tracepoint BPF
program is much easier. bpf_program__attach_tracepoint manages the
enable of tracepoint event and attach of BPF programs to it with a
single interface bpf_link, so there is no need to manage event_fd and
prog_fd separately.

This commit refactors xdp_monitor with using this libbpf API, and the
bpf_load is removed and migrated to libbpf.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20201010181734.1109-2-danieltimlee@gmail.com

pr_*() printing helpers are preferred over using bare printk().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The copyright notice alarms checkpatch.pl of usin spaces before tabs.
Fix this.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Move local variables of the same type into a single line for better
readability.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

The structure containing the storeme field is allocated using kzalloc().
There's no need to set it to 0 again.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

simple_strtoul() is deprecated. Use kstrtoint().

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Aling the assignment of a static structure's field to be consistent with
all other instances.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

Checking pointers for NULL value before passing them to container_of()
is pointless because even if we return NULL from the ternary operator,
none of the users checks the returned value but they instead dereference
it unconditionally. AFAICT this cannot really happen either. Simplify
the code by removing the ternary operators from to_childless() et al.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

There's no need for suplemental newlines in the source file - especially
since the examples are well divided with comments already.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>