Commit Graph

26764 Commits

Author SHA1 Message Date
Yonghong Song
ca21a3e5ed selftests/bpf: Fix a few compiler warnings
With clang building selftests/bpf, I hit a few warnings like below:

  .../bpf_iter.c:592:48: warning: variable 'expected_key_c' set but not used [-Wunused-but-set-variable]
  __u32 expected_key_a = 0, expected_key_b = 0, expected_key_c = 0;
                                                ^

  .../bpf_iter.c:688:48: warning: variable 'expected_key_c' set but not used [-Wunused-but-set-variable]
  __u32 expected_key_a = 0, expected_key_b = 0, expected_key_c = 0;
                                                ^

  .../tc_redirect.c:657:6: warning: variable 'target_fd' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized]
  if (!ASSERT_OK_PTR(nstoken, "setns " NS_FWD))
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  .../tc_redirect.c:743:6: note: uninitialized use occurs here
  if (target_fd >= 0)
      ^~~~~~~~~

Removing unused variables and initializing the previously-uninitialized variable
to ensure these warnings are gone.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210917043343.3711917-1-yhs@fb.com
2021-09-17 09:10:54 -07:00
Andrii Nakryiko
942025c9f3 libbpf: Constify all high-level program attach APIs
Attach APIs shouldn't need to modify bpf_program/bpf_map structs, so
change all struct bpf_program and struct bpf_map pointers to const
pointers. This is completely backwards compatible with no functional
change.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-8-andrii@kernel.org
2021-09-17 09:05:41 -07:00
Andrii Nakryiko
91b555d73e libbpf: Schedule open_opts.attach_prog_fd deprecation since v0.7
bpf_object_open_opts.attach_prog_fd makes a pretty strong assumption
that bpf_object contains either only single freplace BPF program or all
of BPF programs in BPF object are freplaces intended to replace
different subprograms of the same target BPF program. This seems both
a bit confusing, too assuming, and limiting.

We've had bpf_program__set_attach_target() API which allows more
fine-grained control over this, on a per-program level. As such, mark
open_opts.attach_prog_fd as deprecated starting from v0.7, so that we
have one more universal way of setting freplace targets. With previous
change to allow NULL attach_func_name argument, and especially combined
with BPF skeleton, arguable bpf_program__set_attach_target() is a more
convenient and explicit API as well.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-7-andrii@kernel.org
2021-09-17 09:05:41 -07:00
Andrii Nakryiko
60aed22076 selftests/bpf: Switch fexit_bpf2bpf selftest to set_attach_target() API
Switch fexit_bpf2bpf selftest to bpf_program__set_attach_target()
instead of using bpf_object_open_opts.attach_prog_fd, which is going to
be deprecated. These changes also demonstrate the new mode of
set_attach_target() in which it allows NULL when the target is BPF
program (attach_prog_fd != 0).

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-6-andrii@kernel.org
2021-09-17 09:05:41 -07:00
Andrii Nakryiko
2d5ec1c66e libbpf: Allow skipping attach_func_name in bpf_program__set_attach_target()
Allow to use bpf_program__set_attach_target to only set target attach
program FD, while letting libbpf to use target attach function name from
SEC() definition. This might be useful for some scenarios where
bpf_object contains multiple related freplace BPF programs intended to
replace different sub-programs in target BPF program. In such case all
programs will have the same attach_prog_fd, but different
attach_func_name. It's convenient to specify such target function names
declaratively in SEC() definitions, but attach_prog_fd is a dynamic
runtime setting.

To simplify such scenario, allow bpf_program__set_attach_target() to
delay BTF ID resolution till the BPF program load time by providing NULL
attach_func_name. In that case the behavior will be similar to using
bpf_object_open_opts.attach_prog_fd (which is marked deprecated since
v0.7), but has the benefit of allowing more control by user in what is
attached to what. Such setup allows having BPF programs attached to
different target attach_prog_fd with target functions still declaratively
recorded in BPF source code in SEC() definitions.

Selftests changes in the next patch should make this more obvious.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-5-andrii@kernel.org
2021-09-17 09:05:00 -07:00
Andrii Nakryiko
277641859e libbpf: Deprecated bpf_object_open_opts.relaxed_core_relocs
It's relevant and hasn't been doing anything for a long while now.
Deprecated it.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-4-andrii@kernel.org
2021-09-17 09:04:12 -07:00
Andrii Nakryiko
23a7baaa93 selftests/bpf: Stop using relaxed_core_relocs which has no effect
relaxed_core_relocs option hasn't had any effect for a while now, stop
specifying it. Next patch marks it as deprecated.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-3-andrii@kernel.org
2021-09-17 09:04:12 -07:00
Andrii Nakryiko
f11f86a393 libbpf: Use pre-setup sec_def in libbpf_find_attach_btf_id()
Don't perform another search for sec_def inside
libbpf_find_attach_btf_id(), as each recognized bpf_program already has
prog->sec_def set.

Also remove unnecessary NULL check for prog->sec_name, as it can never
be NULL.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210916015836.1248906-2-andrii@kernel.org
2021-09-17 09:04:12 -07:00
Matteo Croce
336562752a bpf: Update bpf_get_smp_processor_id() documentation
BPF programs run with migration disabled regardless of preemption, as
they are protected by migrate_disable(). Update the uapi documentation
accordingly.

Signed-off-by: Matteo Croce <mcroce@microsoft.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210914235400.59427-1-mcroce@linux.microsoft.com
2021-09-15 22:39:55 +02:00
Grant Seltzer
69cd823956 libbpf: Add sphinx code documentation comments
This adds comments above five functions in btf.h which document
their uses. These comments are of a format that doxygen and sphinx
can pick up and render. These are rendered by libbpf.readthedocs.org

Signed-off-by: Grant Seltzer <grantseltzer@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210915021951.117186-1-grantseltzer@gmail.com
2021-09-15 13:16:02 -07:00
Yonghong Song
2220ecf55c selftests/bpf: Skip btf_tag test if btf_tag attribute not supported
Commit c240ba2878 ("selftests/bpf: Add a test with a bpf
program with btf_tag attributes") added btf_tag selftest
to test BTF_KIND_TAG generation from C source code, and to
test kernel validation of generated BTF types.
But if an old clang (clang 13 or earlier) is used, the
following compiler warning may be seen:
  progs/tag.c:23:20: warning: unknown attribute 'btf_tag' ignored
and the test itself is marked OK. The compiler warning is bad
and the test itself shouldn't be marked OK.

This patch added the check for btf_tag attribute support.
If btf_tag is not supported by the clang, the attribute will
not be used in the code and the test will be marked as skipped.
For example, with clang 13:
  ./test_progs -t btf_tag
  #21 btf_tag:SKIP
  Summary: 1/0 PASSED, 1 SKIPPED, 0 FAILED

The selftests/README.rst is updated to clarify when the btf_tag
test may be skipped.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210915061036.2577971-1-yhs@fb.com
2021-09-15 08:49:49 -07:00
Yonghong Song
c240ba2878 selftests/bpf: Add a test with a bpf program with btf_tag attributes
Add a bpf program with btf_tag attributes. The program is
loaded successfully with the kernel. With the command
  bpftool btf dump file ./tag.o
the following dump shows that tags are properly encoded:
  [8] STRUCT 'key_t' size=12 vlen=3
          'a' type_id=2 bits_offset=0
          'b' type_id=2 bits_offset=32
          'c' type_id=2 bits_offset=64
  [9] TAG 'tag1' type_id=8 component_id=-1
  [10] TAG 'tag2' type_id=8 component_id=-1
  [11] TAG 'tag1' type_id=8 component_id=1
  [12] TAG 'tag2' type_id=8 component_id=1
  ...
  [21] FUNC_PROTO '(anon)' ret_type_id=2 vlen=1
          'x' type_id=2
  [22] FUNC 'foo' type_id=21 linkage=static
  [23] TAG 'tag1' type_id=22 component_id=0
  [24] TAG 'tag2' type_id=22 component_id=0
  [25] TAG 'tag1' type_id=22 component_id=-1
  [26] TAG 'tag2' type_id=22 component_id=-1
  ...
  [29] VAR 'total' type_id=27, linkage=global
  [30] TAG 'tag1' type_id=29 component_id=-1
  [31] TAG 'tag2' type_id=29 component_id=-1

If an old clang compiler, which does not support btf_tag attribute,
is used, these btf_tag attributes will be silently ignored.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223058.248949-1-yhs@fb.com
2021-09-14 18:45:53 -07:00
Yonghong Song
ad526474ae selftests/bpf: Test BTF_KIND_TAG for deduplication
Add unit tests for BTF_KIND_TAG deduplication for
  - struct and struct member
  - variable
  - func and func argument

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223052.248535-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
35baba7a83 selftests/bpf: Add BTF_KIND_TAG unit tests
Test good and bad variants of BTF_KIND_TAG encoding.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223047.248223-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
3df3bd68d4 selftests/bpf: Change NAME_NTH/IS_NAME_NTH for BTF_KIND_TAG format
BTF_KIND_TAG ELF format has a component_idx which might have value -1.
test_btf may confuse it with common_type.name as NAME_NTH checkes
high 16bit to be 0xffff. Change NAME_NTH high 16bit check to be
0xfffe so it won't confuse with component_idx.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223041.248009-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
71d29c2d47 selftests/bpf: Test libbpf API function btf__add_tag()
Add btf_write tests with btf__add_tag() function.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223036.247560-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
5c07f2fec0 bpftool: Add support for BTF_KIND_TAG
Added bpftool support to dump BTF_KIND_TAG information.
The new bpftool will be used in later patches to dump
btf in the test bpf program object file.

Currently, the tags are not emitted with
  bpftool btf dump file <path> format c
and they are silently ignored.  The tag information is
mostly used in the kernel for verification purpose and the kernel
uses its own btf to check. With adding these tags
to vmlinux.h, tags will be encoded in program's btf but
they will not be used by the kernel, at least for now.
So let us delay adding these tags to format C header files
until there is a real need.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223031.246951-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
5b84bd1036 libbpf: Add support for BTF_KIND_TAG
Add BTF_KIND_TAG support for parsing and dedup.
Also added sanitization for BTF_KIND_TAG. If BTF_KIND_TAG is not
supported in the kernel, sanitize it to INTs.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223025.246687-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
30025e8bd8 libbpf: Rename btf_{hash,equal}_int to btf_{hash,equal}_int_tag
This patch renames functions btf_{hash,equal}_int() to
btf_{hash,equal}_int_tag() so they can be reused for
BTF_KIND_TAG support. There is no functionality change for
this patch.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223020.245829-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
b5ea834dde bpf: Support for new btf kind BTF_KIND_TAG
LLVM14 added support for a new C attribute ([1])
  __attribute__((btf_tag("arbitrary_str")))
This attribute will be emitted to dwarf ([2]) and pahole
will convert it to BTF. Or for bpf target, this
attribute will be emitted to BTF directly ([3], [4]).
The attribute is intended to provide additional
information for
  - struct/union type or struct/union member
  - static/global variables
  - static/global function or function parameter.

For linux kernel, the btf_tag can be applied
in various places to specify user pointer,
function pre- or post- condition, function
allow/deny in certain context, etc. Such information
will be encoded in vmlinux BTF and can be used
by verifier.

The btf_tag can also be applied to bpf programs
to help global verifiable functions, e.g.,
specifying preconditions, etc.

This patch added basic parsing and checking support
in kernel for new BTF_KIND_TAG kind.

 [1] https://reviews.llvm.org/D106614
 [2] https://reviews.llvm.org/D106621
 [3] https://reviews.llvm.org/D106622
 [4] https://reviews.llvm.org/D109560

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223015.245546-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Yonghong Song
41ced4cd88 btf: Change BTF_KIND_* macros to enums
Change BTF_KIND_* macros to enums so they are encoded in dwarf and
appear in vmlinux.h. This will make it easier for bpf programs
to use these constants without macro definitions.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210914223009.245307-1-yhs@fb.com
2021-09-14 18:45:52 -07:00
Andrii Nakryiko
8987ede3ed selftests/bpf: Fix .gitignore to not ignore test_progs.c
List all possible test_progs flavors explicitly to avoid accidentally
ignoring valid source code files. In this case, test_progs.c was still
ignored after recent 809ed84de8 ("selftests/bpf: Whitelist test_progs.h
from .gitignore") fix that added exception only for test_progs.h.

Fixes: 74b5a5968f ("selftests/bpf: Replace test_progs and test_maps w/ general rule")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20210914162228.3995740-1-andrii@kernel.org
2021-09-14 18:41:14 -07:00
Jie Meng
c035407743 bpf,x64 Emit IMUL instead of MUL for x86-64
IMUL allows for multiple operands and saving and storing rax/rdx is no
longer needed. Signedness of the operands doesn't matter here because
the we only keep the lower 32/64 bit of the product for 32/64 bit
multiplications.

Signed-off-by: Jie Meng <jmeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210913211337.1564014-1-jmeng@fb.com
2021-09-14 18:36:36 -07:00
Andrii Nakryiko
b6291a6f30 libbpf: Minimize explicit iterator of section definition array
Remove almost all the code that explicitly iterated BPF program section
definitions in favor of using find_sec_def(). The only remaining user of
section_defs is libbpf_get_type_names that has to iterate all of them to
construct its result.

Having one internal API entry point for section definitions will
simplify further refactorings around libbpf's program section
definitions parsing.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-5-andrii@kernel.org
2021-09-14 15:49:24 -07:00
Andrii Nakryiko
5532dfd42e libbpf: Simplify BPF program auto-attach code
Remove the need to explicitly pass bpf_sec_def for auto-attachable BPF
programs, as it is already recorded at bpf_object__open() time for all
recognized type of BPF programs. This further reduces number of explicit
calls to find_sec_def(), simplifying further refactorings.

No functional changes are done by this patch.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-4-andrii@kernel.org
2021-09-14 15:49:24 -07:00
Andrii Nakryiko
91b4d1d1d5 libbpf: Ensure BPF prog types are set before relocations
Refactor bpf_object__open() sequencing to perform BPF program type
detection based on SEC() definitions before we get to relocations
collection. This allows to have more information about BPF program by
the time we get to, say, struct_ops relocation gathering. This,
subsequently, simplifies struct_ops logic and removes the need to
perform extra find_sec_def() resolution.

With this patch libbpf will require all struct_ops BPF programs to be
marked with SEC("struct_ops") or SEC("struct_ops/xxx") annotations.
Real-world applications are already doing that through something like
selftests's BPF_STRUCT_OPS() macro. This change streamlines libbpf's
internal handling of SEC() definitions and is in the sprit of
upcoming libbpf-1.0 section strictness changes ([0]).

  [0] https://github.com/libbpf/libbpf/wiki/Libbpf:-the-road-to-v1.0#stricter-and-more-uniform-bpf-program-section-name-sec-handling

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-3-andrii@kernel.org
2021-09-14 15:49:24 -07:00
Andrii Nakryiko
53df63ccdc selftests/bpf: Update selftests to always provide "struct_ops" SEC
Update struct_ops selftests to always specify "struct_ops" section
prefix. Libbpf will require a proper BPF program type set in the next
patch, so this prevents tests breaking.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210914014733.2768-2-andrii@kernel.org
2021-09-14 15:49:24 -07:00
Rafael David Tinoco
ca304b40c2 libbpf: Introduce legacy kprobe events support
Allow kprobe tracepoint events creation through legacy interface, as the
kprobe dynamic PMUs support, used by default, was only created in v4.17.

Store legacy kprobe name in struct bpf_perf_link, instead of creating
a new "subclass" off of bpf_perf_link. This is ok as it's just two new
fields, which are also going to be reused for legacy uprobe support in
follow up patches.

Signed-off-by: Rafael David Tinoco <rafaeldtinoco@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210912064844.3181742-1-rafaeldtinoco@gmail.com
2021-09-14 14:44:45 -07:00
Andrii Nakryiko
2f38304127 libbpf: Make libbpf_version.h non-auto-generated
Turn previously auto-generated libbpf_version.h header into a normal
header file. This prevents various tricky Makefile integration issues,
simplifies the overall build process, but also allows to further extend
it with some more versioning-related APIs in the future.

To prevent accidental out-of-sync versions as defined by libbpf.map and
libbpf_version.h, Makefile checks their consistency at build time.

Simultaneously with this change bump libbpf.map to v0.6.

Also undo adding libbpf's output directory into include path for
kernel/bpf/preload, bpftool, and resolve_btfids, which is not necessary
because libbpf_version.h is just a normal header like any other.

Fixes: 0b46b75505 ("libbpf: Add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20210913222309.3220849-1-andrii@kernel.org
2021-09-13 15:36:47 -07:00
Daniel Borkmann
dbd7eb14e0 bpf, selftests: Replicate tailcall limit test for indirect call case
The tailcall_3 test program uses bpf_tail_call_static() where the JIT
would patch a direct jump. Add a new tailcall_6 test program replicating
exactly the same test just ensuring that bpf_tail_call() uses a map
index where the verifier cannot make assumptions this time.

In other words, this will now cover both on x86-64 JIT, meaning, JIT
images with emit_bpf_tail_call_direct() emission as well as JIT images
with emit_bpf_tail_call_indirect() emission.

  # echo 1 > /proc/sys/net/core/bpf_jit_enable
  # ./test_progs -t tailcalls
  #136/1 tailcalls/tailcall_1:OK
  #136/2 tailcalls/tailcall_2:OK
  #136/3 tailcalls/tailcall_3:OK
  #136/4 tailcalls/tailcall_4:OK
  #136/5 tailcalls/tailcall_5:OK
  #136/6 tailcalls/tailcall_6:OK
  #136/7 tailcalls/tailcall_bpf2bpf_1:OK
  #136/8 tailcalls/tailcall_bpf2bpf_2:OK
  #136/9 tailcalls/tailcall_bpf2bpf_3:OK
  #136/10 tailcalls/tailcall_bpf2bpf_4:OK
  #136/11 tailcalls/tailcall_bpf2bpf_5:OK
  #136 tailcalls:OK
  Summary: 1/11 PASSED, 0 SKIPPED, 0 FAILED

  # echo 0 > /proc/sys/net/core/bpf_jit_enable
  # ./test_progs -t tailcalls
  #136/1 tailcalls/tailcall_1:OK
  #136/2 tailcalls/tailcall_2:OK
  #136/3 tailcalls/tailcall_3:OK
  #136/4 tailcalls/tailcall_4:OK
  #136/5 tailcalls/tailcall_5:OK
  #136/6 tailcalls/tailcall_6:OK
  [...]

For interpreter, the tailcall_1-6 tests are passing as well. The later
tailcall_bpf2bpf_* are failing due lack of bpf2bpf + tailcall support
in interpreter, so this is expected.

Also, manual inspection shows that both loaded programs from tailcall_3
and tailcall_6 test case emit the expected opcodes:

* tailcall_3 disasm, emit_bpf_tail_call_direct():

  [...]
   b:   push   %rax
   c:   push   %rbx
   d:   push   %r13
   f:   mov    %rdi,%rbx
  12:   movabs $0xffff8d3f5afb0200,%r13
  1c:   mov    %rbx,%rdi
  1f:   mov    %r13,%rsi
  22:   xor    %edx,%edx                 _
  24:   mov    -0x4(%rbp),%eax          |  limit check
  2a:   cmp    $0x20,%eax               |
  2d:   ja     0x0000000000000046       |
  2f:   add    $0x1,%eax                |
  32:   mov    %eax,-0x4(%rbp)          |_
  38:   nopl   0x0(%rax,%rax,1)
  3d:   pop    %r13
  3f:   pop    %rbx
  40:   pop    %rax
  41:   jmpq   0xffffffffffffe377
  [...]

* tailcall_6 disasm, emit_bpf_tail_call_indirect():

  [...]
  47:   movabs $0xffff8d3f59143a00,%rsi
  51:   mov    %edx,%edx
  53:   cmp    %edx,0x24(%rsi)
  56:   jbe    0x0000000000000093        _
  58:   mov    -0x4(%rbp),%eax          |  limit check
  5e:   cmp    $0x20,%eax               |
  61:   ja     0x0000000000000093       |
  63:   add    $0x1,%eax                |
  66:   mov    %eax,-0x4(%rbp)          |_
  6c:   mov    0x110(%rsi,%rdx,8),%rcx
  74:   test   %rcx,%rcx
  77:   je     0x0000000000000093
  79:   pop    %rax
  7a:   mov    0x30(%rcx),%rcx
  7e:   add    $0xb,%rcx
  82:   callq  0x000000000000008e
  87:   pause
  89:   lfence
  8c:   jmp    0x0000000000000087
  8e:   mov    %rcx,(%rsp)
  92:   retq
  [...]

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Johan Almbladh <johan.almbladh@anyfinetworks.com>
Acked-by: Paul Chaignon <paul@cilium.io>
Link: https://lore.kernel.org/bpf/CAM1=_QRyRVCODcXo_Y6qOm1iT163HoiSj8U2pZ8Rj3hzMTT=HQ@mail.gmail.com
Link: https://lore.kernel.org/bpf/20210910091900.16119-1-daniel@iogearbox.net
2021-09-13 14:52:22 -07:00
Song Liu
025bd7c753 selftests/bpf: Add test for bpf_get_branch_snapshot
This test uses bpf_get_branch_snapshot from a fexit program. The test uses
a target function (bpf_testmod_loop_test) and compares the record against
kallsyms. If there isn't enough record matching kallsyms, the test fails.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210910183352.3151445-4-songliubraving@fb.com
2021-09-13 10:53:50 -07:00
Song Liu
856c02dbce bpf: Introduce helper bpf_get_branch_snapshot
Introduce bpf_get_branch_snapshot(), which allows tracing pogram to get
branch trace from hardware (e.g. Intel LBR). To use the feature, the
user need to create perf_event with proper branch_record filtering
on each cpu, and then calls bpf_get_branch_snapshot in the bpf function.
On Intel CPUs, VLBR event (raw event 0x1b00) can be use for this.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210910183352.3151445-3-songliubraving@fb.com
2021-09-13 10:53:50 -07:00
Vadim Fedorenko
3384c7c764 selftests/bpf: Test new __sk_buff field hwtstamp
Analogous to the gso_segs selftests introduced in commit d9ff286a0f
("bpf: allow BPF programs access skb_shared_info->gso_segs field").

Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210909220409.8804-3-vfedorenko@novek.ru
2021-09-10 23:20:13 +02:00
Vadim Fedorenko
f64c4acea5 bpf: Add hardware timestamp field to __sk_buff
BPF programs may want to know hardware timestamps if NIC supports
such timestamping.

Expose this data as hwtstamp field of __sk_buff the same way as
gso_segs/gso_size. This field could be accessed from the same
programs as tstamp field, but it's read-only field. Explicit test
to deny access to padding data is added to bpf_skb_is_valid_access.

Also update BPF_PROG_TEST_RUN tests of the feature.

Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20210909220409.8804-2-vfedorenko@novek.ru
2021-09-10 23:19:58 +02:00
Magnus Karlsson
909f0e2820 selftests: xsk: Add tests for 2K frame size
Add tests for 2K frame size. Both a standard send and receive test and
one testing for invalid descriptors when the frame size is 2K.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-21-magnus.karlsson@gmail.com
2021-09-10 21:15:32 +02:00
Magnus Karlsson
0d1b7f3a00 selftests: xsk: Add tests for invalid xsk descriptors
Add tests for invalid xsk descriptors in the Tx ring. A number of
handcrafted nasty invalid descriptors are created and submitted to the
tx ring to check that they are validated correctly. Corner case valid
ones are also sent. The tests are run for both aligned and unaligned
mode.

pkt_stream_set() is introduced to be able to create a hand-crafted
packet stream where every single packet is specified in detail.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-20-magnus.karlsson@gmail.com
2021-09-10 21:15:32 +02:00
Magnus Karlsson
6ce67b5165 selftests: xsk: Eliminate test specific if-statement in test runner
Eliminate a test specific if-statement for the RX_FILL_EMTPY stats
test that is present in the test runner. We can do this as we now have
the use_addr_for_fill option. Just create and empty Rx packet stream
and indicated that the test runner should use the addresses in that to
populate the fill ring. As there are no packets in the stream, the
fill ring will be empty and we will get the error stats that we want
to test.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-19-magnus.karlsson@gmail.com
2021-09-10 21:15:32 +02:00
Magnus Karlsson
a4ba98dd0c selftests: xsk: Add test for unaligned mode
Add a test for unaligned mode in which packet buffers can be placed
anywhere within the umem. Some packets are made to straddle page
boundaries in order to check for correctness. On the Tx side, buffers
are now allocated according to the addresses found in the packet
stream. Thus, the placement of buffers can be controlled with the
boolean use_addr_for_fill in the packet stream.

One new pkt_stream interface is introduced: pkt_stream_replace_half()
that replaces every other packet in the default packet stream with the
specified new packet. The constant DEFAULT_OFFSET is also
introduced. It specifies at what offset from the start of a chunk a Tx
packet is placed by the sending thread. This is just to be able to
test that it is possible to send packets at an offset not equal to
zero.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-18-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
605091c510 selftests: xsk: Introduce replacing the default packet stream
Introduce the concept of a default packet stream that is the set of
packets sent by most tests. Then add the ability to replace it for a
test that would like to send or receive something else through the use
of the function pkt_stream_replace() and then restored with
pkt_stream_restore_default(). These are then used to convert the
STAT_TEST_TX_INVALID to use these new APIs.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-17-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
8abf6f725a selftests: xsk: Allow for invalid packets
Allow for invalid packets to be sent. These are verified by the Rx
thread not to be received. Or put in another way, if they are
received, the test will fail. This feature will be used to eliminate
an if statement for a stats test and will also be used by other tests
in later patches. The previous code could only deal with valid
packets.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-16-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
8ce7192b50 selftests: xsk: Eliminate MAX_SOCKS define
Remove the MAX_SOCKS define as it always will be one for the forseable
future and the code does not work for any other case anyway.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-15-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
e2d850d534 selftests: xsx: Make pthreads local scope
Make the pthread_t variables local scope instead of global. No reason
for them to be global.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-14-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
af6731d1e1 selftests: xsk: Make xdp_flags and bind_flags local
Make xdp_flags and bind_flags local instead of global by moving them
into the interface object. These flags decide if the socket should be
created in SKB mode or in DRV mode and therefore they are sticky and
will survive a test_spec_reset. Since every test is first run in SKB
mode then in DRV mode, this change only happens once. With this
change, the configured_mode global variable can also be
erradicated. The first test_spec_init() also becomes superfluous and
can be eliminated.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-13-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
85c6c95739 selftests: xsk: Specify number of sockets to create
Add the ability in the test specification to specify numbers of
sockets to create. The default is one socket. This is then used to
remove test specific if-statements around the bpf_res tests.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-12-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
55be575dc1 selftests: xsk: Replace second_step global variable
Replace the second_step global variable with a test specification
variable called total_steps that a test can be set to indicate how
many times the packet stream should be sent without reinitializing any
sockets. This eliminates test specific code in the test runner around
the bidirectional test.

The total_steps variable is 1 by default as most tests only need a
single round of packets.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-11-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
1856c24db0 selftests: xsk: Introduce rx_on and tx_on in ifobject
Introduce rx_on and tx_on in the ifobject so that we can describe if
the thread should create a socket with only tx, rx, or both. This
eliminates some test specific if statements from the code. We can also
eliminate the flow vector structure now as this is fully specified
by the tx_on and rx_on variables.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-10-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
119d4b02fe selftests: xsk: Add use_poll to ifobject
Add a use_poll option to the ifobject so that we do not need to use a
test specific if-statement in the test runner.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-9-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
53cb3cec2f selftests: xsx: Introduce test name in test spec
Introduce the test name in the test specification. This so we can set
the name locally in the test function and simplify the logic for
printing out test results.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-8-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
c160d7afba selftests: xsk: Make frame_size configurable
Make the frame size configurable instead of it being hard coded to a
default. This is a property of the umem and will make it possible to
implement tests for different umem frame sizes in a later patch.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-7-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00
Magnus Karlsson
4bf8ee65ba selftests: xsk: Move rxqsize into xsk_socket_info
Move the global variable rxqsize to struct xsk_socket_info as it
describes the size of a ring in that struct. By default, it is set to
the size dictated by libbpf.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Link: https://lore.kernel.org/bpf/20210907071928.9750-6-magnus.karlsson@gmail.com
2021-09-10 21:15:31 +02:00