Commit graph

683 commits

Author SHA1 Message Date
Daniel T. Lee
5062a0af2b samples/bpf: fix broken map lookup probe
[ Upstream commit d93a7cf6ca ]

In the commit 7c4cd051ad ("bpf: Fix syscall's stackmap lookup
potential deadlock"), a potential deadlock issue was addressed, which
resulted in *_map_lookup_elem not triggering BPF programs.
(prior to lookup, bpf_disable_instrumentation() is used)

To resolve the broken map lookup probe using "htab_map_lookup_elem",
this commit introduces an alternative approach. Instead, it utilize
"bpf_map_copy_value" and apply a filter specifically for the hash table
with map_type.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Fixes: 7c4cd051ad ("bpf: Fix syscall's stackmap lookup potential deadlock")
Link: https://lore.kernel.org/r/20230818090119.477441-8-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-13 09:48:06 +02:00
Daniel T. Lee
1c22f35ed8 samples/bpf: fix bio latency check with tracepoint
[ Upstream commit 92632115fb ]

Recently, a new tracepoint for the block layer, specifically the
block_io_start/done tracepoints, was introduced in commit 5a80bd075f
("block: introduce block_io_start/block_io_done tracepoints").

Previously, the kprobe entry used for this purpose was quite unstable
and inherently broke relevant probes [1]. Now that a stable tracepoint
is available, this commit replaces the bio latency check with it.

One of the changes made during this replacement is the key used for the
hash table. Since 'struct request' cannot be used as a hash key, the
approach taken follows that which was implemented in bcc/biolatency [2].
(uses dev:sector for the key)

[1]: https://github.com/iovisor/bcc/issues/4261
[2]: https://github.com/iovisor/bcc/pull/4691

Fixes: 450b7879e3 ("block: move blk_account_io_{start,done} to blk-mq.c")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230818090119.477441-7-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-13 09:48:06 +02:00
Jesper Dangaard Brouer
00139f8a07 samples/bpf: xdp1 and xdp2 reduce XDPBUFSIZE to 60
[ Upstream commit 60548b825b ]

Default samples/pktgen scripts send 60 byte packets as hardware adds
4-bytes FCS checksum, which fulfils minimum Ethernet 64 bytes frame
size.

XDP layer will not necessary have access to the 4-bytes FCS checksum.

This leads to bpf_xdp_load_bytes() failing as it tries to copy 64-bytes
from an XDP packet that only have 60-bytes available.

Fixes: 7722517422 ("samples/bpf: fixup some tools to be able to support xdp multibuffer")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Link: https://lore.kernel.org/bpf/168545704139.2996228.2516528552939485216.stgit@firesoul
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19 16:35:25 +02:00
Pengcheng Yang
7c08d1b0d1 samples/bpf: Fix buffer overflow in tcp_basertt
[ Upstream commit f4dea9689c ]

Using sizeof(nv) or strlen(nv)+1 is correct.

Fixes: c890063e44 ("bpf: sample BPF_SOCKET_OPS_BASE_RTT program")
Signed-off-by: Pengcheng Yang <yangpc@wangsu.com>
Link: https://lore.kernel.org/r/1683276658-2860-1-git-send-email-yangpc@wangsu.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-19 16:35:22 +02:00
Andrii Nakryiko
a820ca1a73 samples/bpf: Drop unnecessary fallthrough
__fallthrough is now not supported. Instead of renaming it to
now-canonical ([0]) fallthrough pseudo-keyword, just get rid of it and
equate 'h' case to default case, as both emit usage information and
succeed.

  [0] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230516001718.317177-1-andrii@kernel.org
2023-05-16 19:44:05 +02:00
Rong Tao
4a1e885c6d samples/bpf: sampleip: Replace PAGE_OFFSET with _text address
Macro PAGE_OFFSET(0xffff880000000000) in sampleip_user.c is inaccurate,
for example, in aarch64 architecture, this value depends on the
CONFIG_ARM64_VA_BITS compilation configuration, this value defaults to 48,
the corresponding PAGE_OFFSET is 0xffff800000000000, if we use the value
defined in sampleip_user.c, then all KSYMs obtained by sampleip are (user)

Symbol error due to PAGE_OFFSET error:

    $ sudo ./sampleip 1
    Sampling at 99 Hertz for 1 seconds. Ctrl-C also ends.
    ADDR                KSYM                             COUNT
    0xffff80000810ceb8  (user)                           1
    0xffffb28ec880      (user)                           1
    0xffff8000080c82b8  (user)                           1
    0xffffb23fed24      (user)                           1
    0xffffb28944fc      (user)                           1
    0xffff8000084628bc  (user)                           1
    0xffffb2a935c0      (user)                           1
    0xffff80000844677c  (user)                           1
    0xffff80000857a3a4  (user)                           1
    ...

A few examples of addresses in the CONFIG_ARM64_VA_BITS=48 environment in
the aarch64 environment:

    $ sudo head /proc/kallsyms
    ffff8000080a0000 T _text
    ffff8000080b0000 t gic_handle_irq
    ffff8000080b0000 T _stext
    ffff8000080b0000 T __irqentry_text_start
    ffff8000080b00b0 t gic_handle_irq
    ffff8000080b0230 t gic_handle_irq
    ffff8000080b03b4 T __irqentry_text_end
    ffff8000080b03b8 T __softirqentry_text_start
    ffff8000080b03c0 T __do_softirq
    ffff8000080b0718 T __entry_text_start

We just need to replace the PAGE_OFFSET with the address _text in
/proc/kallsyms to solve this problem:

    $ sudo ./sampleip 1
    Sampling at 99 Hertz for 1 seconds. Ctrl-C also ends.
    ADDR                KSYM                             COUNT
    0xffffb2892ab0      (user)                           1
    0xffffb2b1edfc      (user)                           1
    0xffff800008462834  __arm64_sys_ppoll                1
    0xffff8000084b87f4  eventfd_read                     1
    0xffffb28e6788      (user)                           1
    0xffff8000081e96d8  rcu_all_qs                       1
    0xffffb2ada878      (user)                           1
    ...

Signed-off-by: Rong Tao <rongtao@cestc.cn>
Link: https://lore.kernel.org/r/tencent_A0E82E0BEE925285F8156D540731DF805F05@qq.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-04-13 21:57:11 -07:00
Hao Zeng
23acb14af1 samples/bpf: Fix fout leak in hbm's run_bpf_prog
Fix fout being fopen'ed but then not subsequently fclose'd. In the affected
branch, fout is otherwise going out of scope.

Signed-off-by: Hao Zeng <zenghao@kylinos.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230411084349.1999628-1-zenghao@kylinos.cn
2023-04-13 15:08:45 +02:00
Ross Zwisler
27d7fdf06f bpf: use canonical ftrace path
The canonical location for the tracefs filesystem is at /sys/kernel/tracing.

But, from Documentation/trace/ftrace.rst:

  Before 4.1, all ftrace tracing control files were within the debugfs
  file system, which is typically located at /sys/kernel/debug/tracing.
  For backward compatibility, when mounting the debugfs file system,
  the tracefs file system will be automatically mounted at:

  /sys/kernel/debug/tracing

Many comments and samples in the bpf code still refer to this older
debugfs path, so let's update them to avoid confusion.  There are a few
spots where the bpf code explicitly checks both tracefs and debugfs
(tools/bpf/bpftool/tracelog.c and tools/lib/api/fs/fs.c) and I've left
those alone so that the tools can continue to work with both paths.

Signed-off-by: Ross Zwisler <zwisler@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20230313205628.1058720-2-zwisler@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-03-13 21:51:30 -07:00
Ilya Leoshkevich
c0ca277bb8 samples/bpf: Use bpf_{btf,link,map,prog}_get_info_by_fd()
Use the new type-safe wrappers around bpf_obj_get_info_by_fd().

Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230214231221.249277-5-iii@linux.ibm.com
2023-02-16 15:32:45 -08:00
Rong Tao
06744f2469 samples/bpf: Add openat2() enter/exit tracepoint to syscall_tp sample
Commit fe3300897cbf("samples: bpf: fix syscall_tp due to unused syscall")
added openat() syscall tracepoints. This patch adds support for
openat2() as well.

Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_9381CB1A158ED7ADD12C4406034E21A3AC07@qq.com
2023-02-08 16:50:42 -08:00
Daniel T. Lee
e04946f54c samples/bpf: change _kern suffix to .bpf with BPF test programs
This commit changes the _kern suffix to .bpf with the BPF test programs.
With this modification, test programs will inherit the benefit of the
new CLANG-BPF compile target.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-11-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
e8acf8f47a samples/bpf: use vmlinux.h instead of implicit headers in BPF test program
This commit applies vmlinux.h to BPF functionality testing program.
Macros that were not defined despite migration to "vmlinux.h" were
defined separately in individual files.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-10-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
c2f4f5593e samples/bpf: replace BPF programs header with net_shared.h
This commit applies "net_shared.h" to BPF programs to remove existing
network related header dependencies. Also, this commit removes
unnecessary headers before applying "vmlinux.h" to the BPF programs.

Mostly, endianness conversion function has been applied to the source.
In addition, several macros have been defined to fulfill the INET,
TC-related constants.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-9-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
e69fe84595 samples/bpf: split common macros to net_shared.h
Currently, many programs under sample/bpf often include individual
macros by directly including the header under "linux/" rather than
using the "vmlinux.h" header.

However, there are some problems with migrating to "vmlinux.h" because
there is no definition for utility functions such as endianness
conversion (ntohs/htons). Fortunately, the xdp_sample program already
has a function that can be replaced to solve this problem.

Therefore, this commit attempts to separate these functions into a file
called net_shared.h to make them universally available. Additionally,
this file includes network-related macros that are not defined in
"vmlinux.h". (inspired by 'selftests' bpf_tracing_net.h)

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-8-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
a1f93c8fb0 samples/bpf: replace legacy map with the BTF-defined map
With libbpf 1.0 release, support for legacy BPF map declaration syntax
had been dropped. If you run a program using legacy BPF in the latest
libbpf, the following error will be output.

    libbpf: map 'lwt_len_hist_map' (legacy): legacy map definitions are deprecated, use BTF-defined maps instead
    libbpf: Use of BPF_ANNOTATE_KV_PAIR is deprecated, use BTF-defined maps in .maps section instead

This commit replaces legacy map with the BTF-defined map.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-7-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
58e975d014 samples/bpf: replace broken overhead microbenchmark with fib_table_lookup
The test_overhead bpf program is designed to compare performance
between tracepoint and kprobe. Initially it used task_rename and
urandom_read tracepoint.

However, commit 14c174633f ("random: remove unused tracepoints")
removed urandom_read tracepoint, and for this reason the test_overhead
got broken.

This commit introduces new microbenchmark using fib_table_lookup.
This microbenchmark sends UDP packets to localhost in order to invoke
fib_table_lookup.

In a nutshell:
fd = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP);
addr.sin_addr.s_addr = inet_addr(DUMMY_IP);
addr.sin_port = htons(DUMMY_PORT);
for() {
    sendto(fd, buf, strlen(buf), 0,
            (struct sockaddr *)&addr, sizeof(addr));
}

on 4 cpus in parallel:
                                            lookup per sec
base (no tracepoints, no kprobes)               381k
with kprobe at fib_table_lookup()               325k
with tracepoint at fib:fib_table_lookup         330k
with raw_tracepoint at fib:fib_table_lookup     365k

Fixes: 14c174633f ("random: remove unused tracepoints")

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-6-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
31b12a4159 samples/bpf: fix broken cgroup socket testing
Currently, executing test_cgrp2_sock2 fails due to wrong section
header. This 'cgroup/sock1' style section is previously used at
'samples/bpf_load' (deprecated) BPF loader. Because this style isn't
supported in libbpf, this commit fixes this problem by correcting the
section header.

    $ sudo ./test_cgrp2_sock2.sh
    libbpf: prog 'bpf_prog1': missing BPF prog type, check ELF section name 'cgroup/sock1'
    libbpf: prog 'bpf_prog1': failed to load: -22
    libbpf: failed to load object './sock_flags_kern.o'
    ERROR: loading BPF object file failed

In addition, this BPF program filters ping packets by comparing whether
the socket type uses SOCK_RAW. However, after the ICMP socket[1] was
developed, ping sends ICMP packets using SOCK_DGRAM. Therefore, in this
commit, the packet filtering is changed to use SOCK_DGRAM instead of
SOCK_RAW.

    $ strace --trace socket ping -6 -c1 -w1 ::1
    socket(AF_INET6, SOCK_DGRAM, IPPROTO_ICMPV6) = 3

[1]: https://lwn.net/Articles/422330/

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-5-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
dac808c907 samples/bpf: fix broken lightweight tunnel testing
The test_lwt_bpf is a script that tests the functionality of BPF through
the output of the ftrace with bpf_trace_printk. Currently, this program
is not operating normally for several reasons.

First of all, this test script can't parse the ftrace results properly.
GNU sed tries to be as greedy as possible when attempting pattern
matching. Due to this, cutting metadata (such as timestamp) from the
log entry of ftrace doesn't work properly, and also desired log isn't
extracted properly. To make sed stripping clearer, 'nocontext-info'
option with the ftrace has been used to remove metadata from the log.
Also, instead of using unclear pattern matching, this commit specifies
an explicit parse pattern.

Also, unlike before when this test was introduced, the way
bpf_trace_printk behaves has changed[1]. The previous bpf_trace_printk
had to always have '\n' in order to print newline, but now that the
bpf_trace_printk call includes newline by default, so '\n' is no longer
needed.

Lastly with the lwt ENCAP_BPF out, the context information with the
sk_buff protocol is preserved. Therefore, this commit changes the
previous test result from 'protocol 0' to 'protocol 8', which means
ETH_P_IP.

[1]: commit ac5a72ea5c ("bpf: Use dedicated bpf_trace_printk event instead of trace_printk()")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-4-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
f20f064e84 samples/bpf: refactor BPF functionality testing scripts
Currently, some test scripts are experiencing minor errors related to
executing tests.

    $ sudo ./test_cgrp2_sock.sh
    ./test_cgrp2_sock.sh: 22: test_cgrp2_sock: not found

This problem occurs because the path to the execution target is not
properly specified. Therefore, this commit solves this problem by
specifying a relative path to its executables. This commit also makes
a concise refactoring of hard-coded BPF program names.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-3-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
d982a2e306 samples/bpf: ensure ipv6 is enabled before running tests
Currently, a few of BPF tests use ipv6 functionality. The problem here
is that if ipv6 is disabled, these tests will fail, and even if the
test fails, it will not tell you why it failed.

    $ sudo ./test_cgrp2_sock2.sh
    RTNETLINK answers: Permission denied

In order to fix this, this commit ensures ipv6 is enabled prior to
running tests.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-2-danieltimlee@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-01-15 13:32:45 -08:00
Daniel T. Lee
c5ffb26375 samples/bpf: Use BPF_KSYSCALL macro in syscall tracing programs
This commit enhances the syscall tracing programs by using the
BPF_SYSCALL macro to reduce the inconvenience of parsing arguments from
pt_regs. By simplifying argument extraction, bpf program will become
clear to understand.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-6-danieltimlee@gmail.com
2022-12-29 14:22:34 -08:00
Daniel T. Lee
2e5c4dd7f8 samples/bpf: Fix tracex2 by using BPF_KSYSCALL macro
Currently, there is a problem with tracex2, as it doesn't print the
histogram properly and the results are misleading. (all results report
as 0)

The problem is caused by a change in arguments of the function to which
the kprobe connects. This tracex2 bpf program uses kprobe (attached
to __x64_sys_write) to figure out the size of the write system call. In
order to achieve this, the third argument 'count' must be intact.

The following is a prototype of the sys_write variant. (checked with
pfunct)

    ~/git/linux$ pfunct -P fs/read_write.o | grep sys_write
    ssize_t ksys_write(unsigned int fd, const char  * buf, size_t count);
    long int __x64_sys_write(const struct pt_regs  * regs);
    ... cross compile with s390x ...
    long int __s390_sys_write(struct pt_regs * regs);

Since the nature of SYSCALL_WRAPPER function wraps the argument once,
additional process of argument extraction is required to properly parse
the argument.

    #define BPF_KSYSCALL(name, args...)
    ... snip ...
    struct pt_regs *regs = LINUX_HAS_SYSCALL_WRAPPER                    \
			   ? (struct pt_regs *)PT_REGS_PARM1(ctx)       \
			   : ctx;                                       \

In order to fix this problem, the BPF_SYSCALL macro has been used. This
reduces the hassle of parsing arguments from pt_regs. Since the macro
uses the CORE version of argument extraction, additional portability
comes too.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-5-danieltimlee@gmail.com
2022-12-29 14:22:34 -08:00
Daniel T. Lee
d4fffba4d0 samples/bpf: Change _kern suffix to .bpf with syscall tracing program
Currently old compile rule (CLANG-bpf) doesn't contains VMLINUX_H define
flag which is essential for the bpf program that includes "vmlinux.h".
Also old compile rule doesn't directly specify the compile target as bpf,
instead it uses bunch of extra options with clang followed by long chain
of commands. (e.g. clang | opt | llvm-dis | llc)

In Makefile, there is already new compile rule which is more simple and
neat. And it also has -D__VMLINUX_H__ option. By just changing the _kern
suffix to .bpf will inherit the benefit of the new CLANG-BPF compile
target.

Also, this commit adds dummy gnu/stub.h to the samples/bpf directory.
As commit 1c2dd16add ("selftests/bpf: get rid of -D__x86_64__") noted,
compiling with 'clang -target bpf' will raise an error with stubs.h
unless workaround (-D__x86_64) is used. This commit solves this problem
by adding dummy stub.h to make /usr/include/features.h to follow the
expected path as the same way selftests/bpf dealt with.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-4-danieltimlee@gmail.com
2022-12-29 14:22:34 -08:00
Daniel T. Lee
8a4dd0bcbd samples/bpf: Use vmlinux.h instead of implicit headers in syscall tracing program
This commit applies vmlinux.h to syscall tracing program. This change
allows the bpf program to refer to the internal structure as a single
"vmlinux.h" instead of including each header referenced by the bpf
program.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-3-danieltimlee@gmail.com
2022-12-29 14:22:34 -08:00
Daniel T. Lee
1d0c5f6f3d samples/bpf: Use kyscall instead of kprobe in syscall tracing program
Syscall tracing using kprobe is quite unstable. Since it uses the exact
name of the kernel function, the program might broke due to the rename
of a function. The problem can also be caused by a changes in the
arguments of the function to which the kprobe connects.

In this commit, ksyscall is used instead of kprobe. By using ksyscall,
libbpf will detect the appropriate kernel function name.
(e.g. sys_write -> __s390_sys_write). This eliminates the need to worry
about which wrapper function to attach in order to parse arguments.

In addition, ksyscall provides more fine method with attaching system
call, the coarse SYSCALL helper at trace_common.h can be removed.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221224071527.2292-2-danieltimlee@gmail.com
2022-12-29 14:22:34 -08:00
Daniel T. Lee
68be98e0f4 samples/bpf: fix uninitialized warning with test_current_task_under_cgroup
Currently, compiling samples/bpf with LLVM warns about the uninitialized
use of variable with test_current_task_under_cgroup.

    ./samples/bpf/test_current_task_under_cgroup_user.c:57:6:
    warning: variable 'cg2' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
	    if (setup_cgroup_environment())
		^~~~~~~~~~~~~~~~~~~~~~~~~~
    ./samples/bpf/test_current_task_under_cgroup_user.c:106:8:
    note: uninitialized use occurs here
	    close(cg2);
		  ^~~
    ./samples/bpf/test_current_task_under_cgroup_user.c:57:2:
    note: remove the 'if' if its condition is always false
	    if (setup_cgroup_environment())
	    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    ./samples/bpf/test_current_task_under_cgroup_user.c:19:9:
    note: initialize the variable 'cg2' to silence this warning
	    int cg2, idx = 0, rc = 1;
		   ^
		    = 0
    1 warning generated.

This commit resolve this compiler warning by pre-initialize the variable
with error for safeguard.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221218061453.6287-4-danieltimlee@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-12-19 14:21:05 -08:00
Daniel T. Lee
71135b77aa samples/bpf: replace meaningless counter with tracex4
Currently, compiling samples/bpf with LLVM warns about the unused but
set variable with tracex4_user.

    ./samples/bpf/tracex4_user.c:54:14:
    warning: variable 'i' set but not used [-Wunused-but-set-variable]
        int map_fd, i, j = 0;
                    ^
                    1 warning generated.

This commit resolve this compiler warning by replacing the meaningless
counter.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221218061453.6287-3-danieltimlee@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-12-19 14:21:05 -08:00
Daniel T. Lee
13aa2a9284 samples/bpf: remove unused function with test_lru_dist
Currently, compiling samples/bpf with LLVM warns about the unused
function with test_lru_dist.

    ./samples/bpf/test_lru_dist.c:45:19:
    warning: unused function 'list_empty' [-Wunused-function]
    static inline int list_empty(const struct list_head *head)
                      ^
                      1 warning generated.

This commit resolve this compiler warning by removing the abandoned
function.

Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221218061453.6287-2-danieltimlee@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-12-19 14:21:05 -08:00
Rong Tao
19a2bdbaad samples/bpf: Fix wrong allocation size in xdp_router_ipv4_user
prefix_key->data allocates three bytes using alloca(), but four bytes are
actually accessed in the program.

Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/tencent_F9E2E81922B0C181D05B96DAE5AB0ACE6B06@qq.com
2022-11-25 00:21:29 +01:00
Tiezhu Yang
ee748cd95e bpf, samples: Use "grep -E" instead of "egrep"
The latest version of grep (3.8+) claims the egrep is now obsolete so the
build now contains warnings that look like:

  egrep: warning: egrep is obsolescent; using grep -E

Fix this up by moving the related file to use "grep -E" instead.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/1668765001-12477-1-git-send-email-yangtiezhu@loongson.cn
2022-11-18 23:55:02 +01:00
Rong Tao
e5659e4e19 samples/bpf: Fix sockex3 error: Missing BPF prog type
since commit 450b167fb9be("libbpf: clean up SEC() handling"),
sec_def_matches() does not recognize "socket/xxx" as "socket", therefore,
the BPF program type is not recognized.

Instead of sockex3_user.c parsing section names to get the BPF program fd.
We use the program array map to assign a static index to each BPF program
(get inspired by selftests/bpf progs/test_prog_array_init.c).
Therefore, use SEC("socket") as section name instead of SEC("socket/xxx"),
so that the BPF program is parsed to SOCKET_FILTER type. The "missing BPF
prog type" problem is solved.

How to reproduce this error:
$ cd samples/bpf
$ sudo ./sockex3
libbpf: prog 'bpf_func_PARSE_IP': missing BPF prog type, check ELF section name 'socket/3'
libbpf: prog 'bpf_func_PARSE_IP': failed to load: -22
libbpf: failed to load object './sockex3_kern.o'
ERROR: loading BPF object file failed

Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_EBA3C18864069E42175946973C2ACBAF5408@qq.com
2022-11-07 17:13:35 -08:00
Rong Tao
1baa7e3800 samples/bpf: Fix tracex2 error: No such file or directory
since commit c504e5c2f964("net: skb: introduce kfree_skb_reason()")
kfree_skb() is replaced by kfree_skb_reason() and kfree_skb() is set to
the inline function. So, we replace kprobe/kfree_skb with
kprobe/kfree_skb_reason to solve the tracex2 error.

 $ cd samples/bpf
 $ sudo ./tracex2
 libbpf: prog 'bpf_prog2': failed to create kprobe 'kfree_skb+0x0' perf event: No such file or directory
 ERROR: bpf_program__attach failed

Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_0F0DAE84C0B3C42E0B550E5E9F47A9114D09@qq.com
2022-11-04 14:57:31 -07:00
Kang Minchul
3a07dcf8f5 samples/bpf: Fix typo in README
Fix 'cofiguration' typo in BPF samples README.

Signed-off-by: Kang Minchul <tegongkang@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20221030180254.34138-1-tegongkang@gmail.com
2022-11-01 15:25:21 +01:00
Daniel Müller
2c4d72d66b samples/bpf: Fix typos in README
This change fixes some typos found in the BPF samples README file.

Signed-off-by: Daniel Müller <deso@posteo.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20221018163231.1926462-1-deso@posteo.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-10-19 11:30:09 -07:00
Shaomin Deng
01dea9548f samples/bpf: Fix double word in comments
Remove the repeated word "by" in comments.

Signed-off-by: Shaomin Deng <dengshaomin@cdjrlc.com>
Link: https://lore.kernel.org/r/20221017142303.8299-1-dengshaomin@cdjrlc.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-10-19 11:21:49 -07:00
Gerhard Engleder
7a698edf95 samples/bpf: Fix MAC address swapping in xdp2_kern
xdp2_kern rewrites and forwards packets out on the same interface.
Forwarding still works but rewrite got broken when xdp multibuffer
support has been added.

With xdp multibuffer a local copy of the packet has been introduced. The
MAC address is now swapped in the local copy, but the local copy in not
written back.

Fix MAC address swapping be adding write back of modified packet.

Fixes: 7722517422 ("samples/bpf: fixup some tools to be able to support xdp multibuffer")
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Link: https://lore.kernel.org/r/20221015213050.65222-1-gerhard@engleder-embedded.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-10-19 11:06:29 -07:00
Gerhard Engleder
05ee658c65 samples/bpf: Fix map iteration in xdp1_user
BPF map iteration in xdp1_user results in endless loop without any
output, because the return value of bpf_map_get_next_key() is checked
against the wrong value.

Other call locations of bpf_map_get_next_key() check for equal 0 for
continuing the iteration. xdp1_user checks against unequal -1. This is
wrong for a function which can return arbitrary negative errno values,
because a return value of e.g. -2 results in an endless loop.

With this fix xdp1_user is printing statistics again:
proto 0:          1 pkt/s
proto 0:          1 pkt/s
proto 17:     107383 pkt/s
proto 17:     881655 pkt/s
proto 17:     882083 pkt/s
proto 17:     881758 pkt/s

Fixes: bd054102a8 ("libbpf: enforce strict libbpf 1.0 behaviors")
Signed-off-by: Gerhard Engleder <gerhard@engleder-embedded.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221013200922.17167-1-gerhard@engleder-embedded.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2022-10-19 10:56:21 -07:00
Deming Wang
b59cc7fcba samples/bpf: Fix typo in xdp_router_ipv4 sample
Fix typo in xdp_router_ipv4 sample.

Signed-off-by: Deming Wang <wangdeming@inspur.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220927192527.8722-1-wangdeming@inspur.com
2022-09-30 15:04:23 -07:00
Rong Tao
bc069da65e samples/bpf: Replace blk_account_io_done() with __blk_account_io_done()
Since commit be6bfe36db ("block: inline hot paths of blk_account_io_*()")
blk_account_io_*() become inline functions.

Signed-off-by: Rong Tao <rtoax@foxmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/tencent_1CC476835C219FACD84B6715F0D785517E07@qq.com
2022-09-20 17:25:59 -07:00
Alexei Starovoitov
89dc8d0c38 samples/bpf: Reduce syscall overhead in map_perf_test.
Make map_perf_test for preallocated and non-preallocated hash map
spend more time inside bpf program to focus performance analysis
on the speed of update/lookup/delete operations performed by bpf program.

It makes 'perf report' of bpf_mem_alloc look like:
 11.76%  map_perf_test    [k] _raw_spin_lock_irqsave
 11.26%  map_perf_test    [k] htab_map_update_elem
  9.70%  map_perf_test    [k] _raw_spin_lock
  9.47%  map_perf_test    [k] htab_map_delete_elem
  8.57%  map_perf_test    [k] memcpy_erms
  5.58%  map_perf_test    [k] alloc_htab_elem
  4.09%  map_perf_test    [k] __htab_map_lookup_elem
  3.44%  map_perf_test    [k] syscall_exit_to_user_mode
  3.13%  map_perf_test    [k] lookup_nulls_elem_raw
  3.05%  map_perf_test    [k] migrate_enable
  3.04%  map_perf_test    [k] memcmp
  2.67%  map_perf_test    [k] unit_free
  2.39%  map_perf_test    [k] lookup_elem_raw

Reduce default iteration count as well to make 'map_perf_test' quick enough
even on debug kernels.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220902211058.60789-5-alexei.starovoitov@gmail.com
2022-09-05 15:33:05 +02:00
Pu Lehui
2e4966288c samples: bpf: Fix cross-compiling error by using bootstrap bpftool
Currently, when cross compiling bpf samples, the host side cannot
use arch-specific bpftool to generate vmlinux.h or skeleton. Since
samples/bpf use bpftool for vmlinux.h, skeleton, and static linking
only, we can use lightweight bootstrap version of bpftool to handle
these, and it's always host-native.

Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220714024612.944071-2-pulehui@huawei.com
2022-07-15 12:01:30 -07:00
Linkui Xiao
b1fc28b338 samples: bpf: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE
The ARRAY_SIZE macro is more compact and more formal in linux source.

Signed-off-by: Linkui Xiao <xiaolinkui@kylinos.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20220712072302.13761-1-xiaolinkui@kylinos.cn
2022-07-13 21:43:52 -07:00
Jesper Dangaard Brouer
49705c4ab3 samples/bpf: Fix xdp_redirect_map egress devmap prog
LLVM compiler optimized out the memcpy in xdp_redirect_map_egress,
which caused the Ethernet source MAC-addr to always be zero
when enabling the devmap egress prog via cmdline --load-egress.

Issue observed with LLVM version 14.0.0
 - Shipped with Fedora 36 on target: x86_64-redhat-linux-gnu.

In verbose mode print the source MAC-addr in case xdp_devmap_attached
mode is used.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/165754826292.575614.5636444052787717159.stgit@firesoul
2022-07-11 21:14:35 -07:00
Magnus Karlsson
cfb5a2dbf1 bpf, samples: Remove AF_XDP samples
Remove the AF_XDP samples from samples/bpf/ as they are dependent on
the AF_XDP support in libbpf. This support has now been removed in the
1.0 release, so these samples cannot be compiled anymore. Please start
to use libxdp instead. It is backwards compatible with the AF_XDP
support that was offered in libbpf. New samples can be found in the
various xdp-project repositories connected to libxdp and by googling.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Link: https://lore.kernel.org/bpf/20220630093717.8664-1-magnus.karlsson@gmail.com
2022-07-05 11:58:44 +02:00
Andy Gospodarek
7722517422 samples/bpf: fixup some tools to be able to support xdp multibuffer
This changes the section name for the bpf program embedded in these
files to "xdp.frags" to allow the programs to be loaded on drivers that
are using an MTU greater than PAGE_SIZE.  Rather than directly accessing
the buffers, the packet data is now accessed via xdp helper functions to
provide an example for those who may need to write more complex
programs.

v2: remove new unnecessary variable

Signed-off-by: Andy Gospodarek <gospo@broadcom.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/r/20220621175402.35327-1-gospo@broadcom.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2022-06-21 18:55:53 -07:00
Zhengchao Shao
de5bb43826 samples/bpf: Check detach prog exist or not in xdp_fwd
Before detach the prog, we should check detach prog exist or not.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20220606005425.261967-1-shaozhengchao@huawei.com
2022-06-15 17:26:20 -07:00
Lorenzo Bianconi
200a89e3e8 sample: bpf: xdp_router_ipv4: Allow the kernel to send arp requests
Forward the packet to the kernel if the gw router mac address is missing
in to trigger ARP discovery.

Fixes: 85bf1f5169 ("samples: bpf: Convert xdp_router_ipv4 to XDP samples helper")
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/60bde5496d108089080504f58199bcf1143ea938.1653471558.git.lorenzo@kernel.org
2022-06-02 16:26:54 -07:00
Jerome Marchand
ec24704492 samples: bpf: Don't fail for a missing VMLINUX_BTF when VMLINUX_H is provided
samples/bpf build currently always fails if it can't generate
vmlinux.h from vmlinux, even when vmlinux.h is directly provided by
VMLINUX_H variable, which makes VMLINUX_H pointless.
Only fails when neither method works.

Fixes: 384b6b3bbf ("samples: bpf: Add vmlinux.h generation support")
Reported-by: CKI Project <cki-project@redhat.com>
Reported-by: Veronika Kabatova <vkabatov@redhat.com>
Signed-off-by: Jerome Marchand <jmarchan@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220507161635.2219052-1-jmarchan@redhat.com
2022-05-09 17:40:43 -07:00
Zhengchao Shao
d1c57439e4 samples/bpf: Detach xdp prog when program exits unexpectedly in xdp_rxq_info_user
When xdp_rxq_info_user program exits unexpectedly, it doesn't detach xdp
prog of device, and other xdp prog can't be attached to the device. So
call init_exit() to detach xdp prog when program exits unexpectedly.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220427062338.80173-1-shaozhengchao@huawei.com
2022-04-27 19:07:42 -07:00
Zhengchao Shao
db69264f98 samples/bpf: Reduce the sampling interval in xdp1_user
If interval is 2, and sum - prev[key] = 1, the result = 0. This will
mislead the tester that the port has no traffic right now. So reduce the
sampling interval to 1.

Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220419114746.291613-1-shaozhengchao@huawei.com
2022-04-20 14:58:29 -07:00