We currently use module_kallsyms_on_each_symbol that iterates all
modules/symbols and we try to lookup each such address in user
provided symbols/addresses to get list of used modules.

This fix instead only iterates provided kprobe addresses and calls
__module_address on each to get list of used modules. This turned
out to be simpler and also bit faster.

On my setup with workload (executed 10 times):

   # test_progs -t kprobe_multi_bench_attach/modules

Current code:

 Performance counter stats for './test.sh' (5 runs):

    76,081,161,596      cycles:k                   ( +-  0.47% )

           18.3867 +- 0.0992 seconds time elapsed  ( +-  0.54% )

With the fix:

 Performance counter stats for './test.sh' (5 runs):

    74,079,889,063      cycles:k                   ( +-  0.04% )

           17.8514 +- 0.0218 seconds time elapsed  ( +-  0.12% )
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230116101009.23694-4-jolsa@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Add bench test for module portion of the symbols as well.

  # ./test_progs -v -t kprobe_multi_bench_attach_module
  bpf_testmod.ko is already unloaded.
  Loading bpf_testmod.ko...
  Successfully loaded bpf_testmod.ko.
  test_kprobe_multi_bench_attach:PASS:get_syms 0 nsec
  test_kprobe_multi_bench_attach:PASS:kprobe_multi_empty__open_and_load 0 nsec
  test_kprobe_multi_bench_attach:PASS:bpf_program__attach_kprobe_multi_opts 0 nsec
  test_kprobe_multi_bench_attach: found 26620 functions
  test_kprobe_multi_bench_attach: attached in   0.182s
  test_kprobe_multi_bench_attach: detached in   0.082s
  #96      kprobe_multi_bench_attach_module:OK
  Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
  Successfully unloaded bpf_testmod.ko.

It's useful for testing kprobe multi link modules resolving.
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230116101009.23694-3-jolsa@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Currently we traverse all symbols of all modules to find the specified
function for the specified module. But in reality, we just need to find
the given module and then traverse all the symbols in it.

Let's add a new parameter 'const char *modname' to function
module_kallsyms_on_each_symbol(), then we can compare the module names
directly in this function and call hook 'fn' after matching. If 'modname'
is NULL, the symbols of all modules are still traversed for compatibility
with other usage cases.

Phase1: mod1-->mod2..(subsequent modules do not need to be compared)
                |
Phase2:          -->f1-->f2-->f3

Assuming that there are m modules, each module has n symbols on average,
then the time complexity is reduced from O(m * n) to O(m) + O(n).
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Link: https://lore.kernel.org/r/20230116101009.23694-2-jolsa@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

If CONFIG_NF_CONNTRACK=m, there are no definitions of NF_NAT_MANIP_SRC
and NF_NAT_MANIP_DST in vmlinux.h, build test_bpf_nf.c failed.

$ make -C tools/testing/selftests/bpf/

  CLNG-BPF [test_maps] test_bpf_nf.bpf.o
progs/test_bpf_nf.c:160:42: error: use of undeclared identifier 'NF_NAT_MANIP_SRC'
                bpf_ct_set_nat_info(ct, &saddr, sport, NF_NAT_MANIP_SRC);
                                                       ^
progs/test_bpf_nf.c:163:42: error: use of undeclared identifier 'NF_NAT_MANIP_DST'
                bpf_ct_set_nat_info(ct, &daddr, dport, NF_NAT_MANIP_DST);
                                                       ^
2 errors generated.

Copy the definitions in include/net/netfilter/nf_nat.h to test_bpf_nf.c,
in order to avoid redefinitions if CONFIG_NF_CONNTRACK=y, rename them with
___local suffix. This is similar with commit 1058b6a7 ("selftests/bpf:
Do not fail build if CONFIG_NF_CONNTRACK=m/n").

Fixes: b06b45e8 ("selftests/bpf: add tests for bpf_ct_set_nat_info kfunc")
Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/1674028604-7113-1-git-send-email-yangtiezhu@loongson.cnSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Adding verifier tests for loading all types od allowed
sleepable programs plus reject for tp_btf type.
Acked-by: Song Liu <song@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230117223705.440975-2-jolsa@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Currently we allow to load any tracing program as sleepable,
but BPF_TRACE_RAW_TP can't sleep. Making the check explicit
for tracing programs attach types, so sleepable BPF_TRACE_RAW_TP
will fail to load.

Updating the verifier error to mention iter programs as well.
Acked-by: Song Liu <song@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230117223705.440975-1-jolsa@kernel.orgSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Version 1.24 of pahole has the capability to exclude compilation units (CUs)
of specific languages [1] [2]. Rust, as of writing, is not currently supported
by pahole and if it's used with a build that has BTF debugging enabled it
results in malformed kernel and module binaries [3]. So it's better for pahole
to exclude Rust CUs until support for it arrives.
Co-developed-by: Eric Curtin <ecurtin@redhat.com>
Signed-off-by: Eric Curtin <ecurtin@redhat.com>
Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Eric Curtin <ecurtin@redhat.com>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Acked-by: Miguel Ojeda <ojeda@kernel.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=49358dfe2aaae4e90b072332c3e324019826783f [1]
Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=8ee363790b7437283c53090a85a9fec2f0b0fbc4 [2]
Link: https://github.com/Rust-for-Linux/linux/issues/735 [3]
Link: https://lore.kernel.org/bpf/20230111152050.559334-1-yakoyoku@gmail.com

"Daniel T. Lee" says:

====================

Currently, there are many programs under samples/bpf to test the
various functionality of BPF that have been developed for a long time.
However, the kernel (BPF) has changed a lot compared to the 2016 when
some of these test programs were first introduced.

Therefore, some of these programs use the deprecated function of BPF,
and some programs no longer work normally due to changes in the API.

To list some of the kernel changes that this patch set is focusing on,
- legacy BPF map declaration syntax support had been dropped [1]
- bpf_trace_printk() always append newline at the end [2]
- deprecated styled BPF section header (bpf_load style) [3]
- urandom_read tracepoint is removed (used for testing overhead) [4]
- ping sends packet with SOCK_DGRAM instead of SOCK_RAW [5]*
- use "vmlinux.h" instead of including individual headers

In addition to this, this patchset tries to modernize the existing
testing scripts a bit. And for network-related testing programs,
a separate header file was created and applied. (To use the
Endianness conversion function from xdp_sample and bunch of constants)

[1]: https://github.com/libbpf/libbpf/issues/282
[2]: commit ac5a72ea ("bpf: Use dedicated bpf_trace_printk event instead of trace_printk()")
[3]: commit ceb5dea5 ("samples: bpf: Remove bpf_load loader completely")
[4]: commit 14c17463 ("random: remove unused tracepoints")
[5]: https://lwn.net/Articles/422330/

*: This is quite old, but I'm not sure why the code was initially
   developed to filter only SOCK_RAW.
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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

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

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

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

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

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 14c17463 ("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: 14c17463 ("random: remove unused tracepoints")
Signed-off-by: Daniel T. Lee <danieltimlee@gmail.com>
Link: https://lore.kernel.org/r/20230115071613.125791-6-danieltimlee@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

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

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 ac5a72ea ("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.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

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

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

Ziyang Xuan says:

====================

Add ipip6 and ip6ip decap support for bpf_skb_adjust_room().
Main use case is for using cls_bpf on ingress hook to decapsulate
IPv4 over IPv6 and IPv6 over IPv4 tunnel packets.

And add ipip6 and ip6ip decap testcases to verify that
bpf_skb_adjust_room() correctly decapsulate ipip6 and ip6ip
tunnel packets.

$./test_tc_tunnel.sh
ipip
encap 192.168.1.1 to 192.168.1.2, type ipip, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
ipip6
encap 192.168.1.1 to 192.168.1.2, type ipip6, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
ip6ip6
encap fd::1 to fd::2, type ip6tnl, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
sit
encap fd::1 to fd::2, type sit, mac none len 100
test basic connectivity
0
test bpf encap without decap (expect failure)
Ncat: TIMEOUT.
1
test bpf encap with tunnel device decap
0
test bpf encap with bpf decap
0
OK
...
OK. All tests passed

v3:
  - Fix compilation failure of selftests/bpf.
  - Combine two new branches in bpf_skb_adjust_room().
  - Simplify description for new flags BPF_F_ADJ_ROOM_DECAP_L3_IP*.

v2:
  - Use decap flags to indicate the new IP header.
    Do not rely on skb->encapsulation.
====================
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Add ipip6 and ip6ip decap testcases. Verify that bpf_skb_adjust_room()
correctly decapsulate ipip6 and ip6ip tunnel packets.
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/dfd2d8cfdf9111bd129170d4345296f53bee6a67.1673574419.git.william.xuanziyang@huawei.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Add ipip6 and ip6ip decap support for bpf_skb_adjust_room().
Main use case is for using cls_bpf on ingress hook to decapsulate
IPv4 over IPv6 and IPv6 over IPv4 tunnel packets.

Add two new flags BPF_F_ADJ_ROOM_DECAP_L3_IPV{4,6} to indicate the
new IP header version after decapsulating the outer IP header.
Suggested-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://lore.kernel.org/r/b268ec7f0ff9431f4f43b1b40ab856ebb28cb4e1.1673574419.git.william.xuanziyang@huawei.comSigned-off-by: Martin KaFai Lau <martin.lau@kernel.org>

Add the missing space after 'dest' variable assignment.
This change will resolve the following checkpatch.pl
script error:

ERROR: spaces required around that '+=' (ctx:VxW)
Signed-off-by: Roberto Valenzuela <valenzuelarober@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230113180257.39769-1-valenzuelarober@gmail.com

'.' is not allowed in the event name of kprobe. Therefore, we will get a
EINVAL if the kernel function name has a '.' in legacy kprobe attach
case, such as 'icmp_reply.constprop.0'.

In order to adapt this case, we need to replace the '.' with other char
in gen_kprobe_legacy_event_name(). And I use '_' for this propose.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com

When the clang toolchain has stack protection enabled in order to be
consistent with gcc - which just happens to be the case on Gentoo -
the bpftool build fails:

  [...]
  clang \
	-I. \
	-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \
	-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \
	-g -O2 -Wall -target bpf -c skeleton/pid_iter.bpf.c -o pid_iter.bpf.o
  clang \
	-I. \
	-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \
	-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \
	-g -O2 -Wall -target bpf -c skeleton/profiler.bpf.c -o profiler.bpf.o
  skeleton/profiler.bpf.c:40:14: error: A call to built-in function '__stack_chk_fail' is not supported.
  int BPF_PROG(fentry_XXX)
                ^
  skeleton/profiler.bpf.c:94:14: error: A call to built-in function '__stack_chk_fail' is not supported.
  int BPF_PROG(fexit_XXX)
                ^
  2 errors generated.
  [...]

Since stack-protector makes no sense for the BPF bits just unconditionally
disable it.

Bug: https://bugs.gentoo.org/890638Signed-off-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/74cd9d2e-6052-312a-241e-2b514a75c92c@applied-asynchrony.com

Magnus Karlsson says:

====================

This is a patch set of various performance improvements, fixes, and
the introduction of more than one XDP program to the xsk selftests
framework so we can test more things in the future such as upcoming
multi-buffer and metadata support for AF_XDP. The new programs just
reuse the framework that all the other eBPF selftests use. The new
feature is used to implement one new test that does XDP_DROP on every
other packet. More tests using this will be added in future commits.

Contents:

* The run-time of the test suite is cut by 10x when executing the
  tests on a real NIC, by only attaching the XDP program once per mode
  tested, instead of once per test program.

* Over 700 lines of code have been removed. The xsk.c control file was
  moved straight over from libbpf when the xsk support was deprecated
  there. As it is now not used as library code that has to work with
  all kinds of versions of Linux, a lot of code could be dropped or
  simplified.

* Add a new command line option "-d" that can be used when a test
  fails and you want to debug it with gdb or some other debugger. The
  option creates the two veth netdevs and prints them to the screen
  without deleting them afterwards. This way these veth netdevs can be
  used when running xskxceiver in a debugger.

* Implemented the possibility to load external XDP programs so we can
  have more than the default one. This feature is used to implement a
  test where every other packet is dropped. Good exercise for the
  recycling mechanism of the xsk buffer pool used in zero-copy mode.

* Various clean-ups and small fixes in patches 1 to 5. None of these
  fixes has any impact on the correct execution of the tests when they
  pass, though they can be irritating when a test fails. IMHO, they do
  not need to go to bpf as they will not fix anything there. The first
  version of patches 1, 2, and 4 where previously sent to bpf, but has
  now been included here.

v2 -> v3:
* Fixed compilation error for llvm [David]
* Made the function xsk_is_in_drv_mode(ifobj) more generic by changing
  it to xsk_is_in_mode(ifobj, xdp_mode) [Maciej]
* Added Maciej's acks to all the patches

v1 -> v2:
* Fixed spelling error in commit message of patch #6 [Björn]
* Added explanation on why it is safe to use C11 atomics in patch #7
  [Daniel]
* Put all XDP programs in the same file so that adding more XDP
  programs to xskxceiver.c becomes more scalable in patches #11 and
  #12 [Maciej]
* Removed more dead code in patch #8 [Maciej]
* Removed stale %s specifier in error print, patch #9 [Maciej]
* Changed name of XDP_CONSUMES_SOME_PACKETS to XDP_DROP_HALF to
  hopefully make it clearer [Maciej]
* ifobj_rx and ifobj_tx name changes in patch #13 [Maciej]
* Simplified XDP attachment code in patch #15 [Maciej]

Patches:
1-5:   Small fixes and clean-ups
6:     New convenient debug option when using a debugger such as gdb
7-8:   Removal of unnecessary code
9:     Add the ability to load external XDP programs
10-11: Removal of more unnecessary code
12:    Implement a new test where every other packet is XDP_DROP:ed
13:    Unify the thread dispatching code
14-15: Simplify the way tests are written when using custom packet_streams
       or custom XDP programs

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

Implement automatic switching of XDP programs and execution modes if
needed by a test. This makes it much simpler to write a test as it
only has to say what XDP program it needs if it is not the default
one. This also makes it possible to remove the initial explicit
attachment of the XDP program as well as the explicit mode switch in
the code. These are now handled by the same code that just checks if a
switch is necessary, so no special cases are needed.

The default XDP program for all tests is one that sends all packets to
the AF_XDP socket. If you need another one, please use the new
function test_spec_set_xdp_prog() to specify what XDP programs and
maps to use for this test.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-16-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Automatically restore the default packet stream if needed at the end
of each test. This so that test writers do not forget to do this.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-15-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Make the thread dispatching code common by unifying the dual and
single thread dispatcher code. This so we do not have to add code in
two places in upcoming commits.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-14-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Add a new test where some of the packets are not passed to the AF_XDP
socket and instead get a XDP_DROP verdict. This is important as it
tests the recycling mechanism of the buffer pool. If a packet is not
sent to the AF_XDP socket, the buffer the packet resides in is instead
recycled so it can be used again without the round-trip to user
space. The test introduces a new XDP program that drops every other
packet.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-13-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Get rid of the built-in XDP program that was part of the old libbpf
code in xsk.c and replace it with an eBPF program build using the
framework by all the other bpf selftests. This will form the base for
adding more programs in later commits.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-12-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Remove unnecessary code in the control path. This is located in the
file xsk.c that was moved from libbpf when the xsk support there was
deprecated. Some of the code there is not needed anymore as the
selftests are only guaranteed to run on the kernel it is shipped
with. Therefore, all the code that has to deal with compatibility of
older kernels can be dropped and also any other function that is not
of any use for the tests.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-11-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Load and attach the XDP program only once per XDP mode that is being
executed. Today, the XDP program is loaded and attached for every
test, then unloaded, which takes a long time on real NICs, since they
have to reconfigure their HW, in contrast to veth. The test suite now
completes in 21 seconds, instead of 207 seconds previously on my
machine. This is a speed-up of around 10x.

This is accomplished by moving the XDP loading from the worker threads
to the main thread and replacing the XDP loading interfaces of xsk.c
that was taken from the xsk support in libbpf, with something more
explicit that is more useful for these tests. Instead, the relevant
file descriptors and ifindexes are just passed down to the new
functions.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-10-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Remove the namespaces used as they fill no function. This will
simplify the code for speeding up the tests in the following commits.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-9-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Replace our own homegrown assembly store/release and load/acquire
implementations with the HW agnositic atomic APIs C11 offers. This to
make the code more portable, easier to read, and reduce the
maintenance burden.

The original code used load-acquire and store-release barriers
hand-coded in assembly. Since C11, these kind of operations are
offered as built-ins in gcc and llvm. The load-acquire operation
prevents hoisting of non-atomic memory operations to before this
operation and it corresponds to the __ATOMIC_ACQUIRE operation in the
built-in atomics. The store-release operation prevents hoisting of
non-atomic memory operations to after this operation and it
corresponds to the __ATOMIC_RELEASE operation in the built-in atomics.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-8-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Add a new option to the test_xsk.sh script that only creates the two
veth netdevs and the extra namespace, then exits without running any
tests. The failed test can then be executed in the debugger without
having to create the netdevs and namespace manually. For ease-of-use,
the veth netdevs to use are printed so they can be copied into the
debugger.

Here is an example how to use it:

> sudo ./test_xsk.sh -d

veth10 veth11

> gdb xskxceiver

In gdb:

run -i veth10 -i veth11

And now the test cases can be debugged with gdb.

If you want to debug the test suite on a real NIC in loopback mode,
there is no need to use this feature as you already know the netdev of
your NIC.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-7-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Remove the unused variable outstanding_tx.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-6-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Print the correct error codes when exiting the test suite due to some
terminal error. Some of these had a switched sign and some of them
printed zero instead of errno.

Fixes: facb7cb2 ("selftests/bpf: Xsk selftests - SKB POLL, NOPOLL")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-5-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Submit the correct number of frames in the function
xsk_populate_fill_ring(). For the tests that set the flag
use_addr_for_fill, uninitialized buffers were sent to the fill ring
following the correct ones. This has no impact on the tests, since
they only use the ones that were initialized. But for correctness,
this should be fixed.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-4-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Do not close descriptors that have never been used. File descriptor
fields that are not in use are erroneously marked with the number 0,
which is a valid fd. Mark unused fds with -1 instead and do not close
these when deleting the socket.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-3-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

Print the correct payload when the packet dump option is selected. The
network to host conversion was forgotten and the payload was
erronously declared to be an int instead of an unsigned int.

Fixes: facb7cb2 ("selftests/bpf: Xsk selftests - SKB POLL, NOPOLL")
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/r/20230111093526.11682-2-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>