Commit Graph

438 Commits

Author SHA1 Message Date
Jakub Sitnicki
ab81e203bc scripts/bpf: Print an error when known types list needs updating
Don't generate a broken bpf_helper_defs.h header if the helper script needs
updating because it doesn't recognize a newly added type. Instead print an
error that explains why the build is failing, clean up the partially
generated header and stop.

v1->v2:
- Switched from temporary file to .DELETE_ON_ERROR.

Fixes: 456a513bb5 ("scripts/bpf: Emit an #error directive known types list needs updating")
Suggested-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191020112344.19395-1-jakub@cloudflare.com
2019-10-20 18:21:21 -07:00
John Fastabend
54b8625cd9 bpf, libbpf: Add kernel version section parsing back
With commit "libbpf: stop enforcing kern_version,..." we removed the
kernel version section parsing in favor of querying for the kernel
using uname() and populating the version using the result of the
query. After this any version sections were simply ignored.

Unfortunately, the world of kernels is not so friendly. I've found some
customized kernels where uname() does not match the in kernel version.
To fix this so programs can load in this environment this patch adds
back parsing the section and if it exists uses the user specified
kernel version to override the uname() result. However, keep most the
kernel uname() discovery bits so users are not required to insert the
version except in these odd cases.

Fixes: 5e61f27070 ("libbpf: stop enforcing kern_version, populate it for users")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157140968634.9073.6407090804163937103.stgit@john-XPS-13-9370
2019-10-18 20:59:10 +02:00
Alexei Starovoitov
f75a697e09 libbpf: Auto-detect btf_id of BTF-based raw_tracepoints
It's a responsiblity of bpf program author to annotate the program
with SEC("tp_btf/name") where "name" is a valid raw tracepoint.
The libbpf will try to find "name" in vmlinux BTF and error out
in case vmlinux BTF is not available or "name" is not found.
If "name" is indeed a valid raw tracepoint then in-kernel BTF
will have "btf_trace_##name" typedef that points to function
prototype of that raw tracepoint. BTF description captures
exact argument the kernel C code is passing into raw tracepoint.
The kernel verifier will check the types while loading bpf program.

libbpf keeps BTF type id in expected_attach_type, but since
kernel ignores this attribute for tracing programs copy it
into attach_btf_id attribute before loading.

Later the kernel will use prog->attach_btf_id to select raw tracepoint
during bpf_raw_tracepoint_open syscall command.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191016032505.2089704-6-ast@kernel.org
2019-10-17 16:44:35 +02:00
Andrii Nakryiko
01340e3191 libbpf: Add BPF-side definitions of supported field relocation kinds
Add enum definition for Clang's __builtin_preserve_field_info()
second argument (info_kind). Currently only byte offset and existence
are supported. Corresponding Clang changes introducing this built-in can
be found at [0]

  [0] https://reviews.llvm.org/D67980

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-5-andriin@fb.com
2019-10-15 16:06:05 -07:00
Andrii Nakryiko
62561eb442 libbpf: Add support for field existance CO-RE relocation
Add support for BPF_FRK_EXISTS relocation kind to detect existence of
captured field in a destination BTF, allowing conditional logic to
handle incompatible differences between kernels.

Also introduce opt-in relaxed CO-RE relocation handling option, which
makes libbpf emit warning for failed relocations, but proceed with other
relocations. Instruction, for which relocation failed, is patched with
(u32)-1 value.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-4-andriin@fb.com
2019-10-15 16:06:05 -07:00
Andrii Nakryiko
291ee02b5e libbpf: Refactor bpf_object__open APIs to use common opts
Refactor all the various bpf_object__open variations to ultimately
specify common bpf_object_open_opts struct. This makes it easy to keep
extending this common struct w/ extra parameters without having to
update all the legacy APIs.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-3-andriin@fb.com
2019-10-15 16:06:05 -07:00
Andrii Nakryiko
511bb0085c libbpf: Update BTF reloc support to latest Clang format
BTF offset reloc was generalized in recent Clang into field relocation,
capturing extra u32 field, specifying what aspect of captured field
needs to be relocated. This changes .BTF.ext's record size for this
relocation from 12 bytes to 16 bytes. Given these format changes
happened in Clang before official released version, it's ok to not
support outdated 12-byte record size w/o breaking ABI.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191015182849.3922287-2-andriin@fb.com
2019-10-15 16:06:05 -07:00
Ivan Khoronzhuk
793a349cd8 libbpf: Add C/LDFLAGS to libbpf.so and test_libpf targets
In case of C/LDFLAGS there is no way to pass them correctly to build
command, for instance when --sysroot is used or external libraries
are used, like -lelf, wich can be absent in toolchain. This can be
used for samples/bpf cross-compiling allowing to get elf lib from
sysroot.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191011002808.28206-13-ivan.khoronzhuk@linaro.org
2019-10-12 16:08:59 -07:00
Ivan Khoronzhuk
5c26f9a783 libbpf: Don't use cxx to test_libpf target
No need to use C++ for test_libbpf target when libbpf is on C and it
can be tested with C, after this change the CXXFLAGS in makefiles can
be avoided, at least in bpf samples, when sysroot is used, passing
same C/LDFLAGS as for lib.

Add "return 0" in test_libbpf to avoid warn, but also remove spaces at
start of the lines to keep same style and avoid warns while apply.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191011002808.28206-12-ivan.khoronzhuk@linaro.org
2019-10-12 16:08:59 -07:00
Andrii Nakryiko
e78dcbf414 libbpf: Handle invalid typedef emitted by old GCC
Old GCC versions are producing invalid typedef for __gnuc_va_list
pointing to void. Special-case this and emit valid:

typedef __builtin_va_list __gnuc_va_list;

Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191011032901.452042-1-andriin@fb.com
2019-10-11 23:11:55 +02:00
Andrii Nakryiko
409017847d libbpf: Generate more efficient BPF_CORE_READ code
Existing BPF_CORE_READ() macro generates slightly suboptimal code. If
there are intermediate pointers to be read, initial source pointer is
going to be assigned into a temporary variable and then temporary
variable is going to be uniformly used as a "source" pointer for all
intermediate pointer reads. Schematically (ignoring all the type casts),
BPF_CORE_READ(s, a, b, c) is expanded into:
({
	const void *__t = src;
	bpf_probe_read(&__t, sizeof(*__t), &__t->a);
	bpf_probe_read(&__t, sizeof(*__t), &__t->b);

	typeof(s->a->b->c) __r;
	bpf_probe_read(&__r, sizeof(*__r), &__t->c);
})

This initial `__t = src` makes calls more uniform, but causes slightly
less optimal register usage sometimes when compiled with Clang. This can
cascase into, e.g., more register spills.

This patch fixes this issue by generating more optimal sequence:
({
	const void *__t;
	bpf_probe_read(&__t, sizeof(*__t), &src->a); /* <-- src here */
	bpf_probe_read(&__t, sizeof(*__t), &__t->b);

	typeof(s->a->b->c) __r;
	bpf_probe_read(&__r, sizeof(*__r), &__t->c);
})

Fixes: 7db3822ab9 ("libbpf: Add BPF_CORE_READ/BPF_CORE_READ_INTO helpers")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191011023847.275936-1-andriin@fb.com
2019-10-11 22:35:46 +02:00
Ilya Maximets
25bfef430e libbpf: Fix passing uninitialized bytes to setsockopt
'struct xdp_umem_reg' has 4 bytes of padding at the end that makes
valgrind complain about passing uninitialized stack memory to the
syscall:

  Syscall param socketcall.setsockopt() points to uninitialised byte(s)
    at 0x4E7AB7E: setsockopt (in /usr/lib64/libc-2.29.so)
    by 0x4BDE035: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:172)
  Uninitialised value was created by a stack allocation
    at 0x4BDDEBA: xsk_umem__create@@LIBBPF_0.0.4 (xsk.c:140)

Padding bytes appeared after introducing of a new 'flags' field.
memset() is required to clear them.

Fixes: 10d30e3017 ("libbpf: add flags to umem config")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191009164929.17242-1-i.maximets@ovn.org
2019-10-09 15:45:37 -07:00
Andrii Nakryiko
b4099769f3 libbpf: Fix struct end padding in btf_dump
Fix a case where explicit padding at the end of a struct is necessary
due to non-standart alignment requirements of fields (which BTF doesn't
capture explicitly).

Fixes: 351131b51c ("libbpf: add btf_dump API for BTF-to-C conversion")
Reported-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191008231009.2991130-2-andriin@fb.com
2019-10-09 15:38:36 -07:00
Andrii Nakryiko
7db3822ab9 libbpf: Add BPF_CORE_READ/BPF_CORE_READ_INTO helpers
Add few macros simplifying BCC-like multi-level probe reads, while also
emitting CO-RE relocations for each read.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-7-andriin@fb.com
2019-10-08 23:16:03 +02:00
Andrii Nakryiko
e01a75c159 libbpf: Move bpf_{helpers, helper_defs, endian, tracing}.h into libbpf
Move bpf_helpers.h, bpf_tracing.h, and bpf_endian.h into libbpf. Move
bpf_helper_defs.h generation into libbpf's Makefile. Ensure all those
headers are installed along the other libbpf headers. Also, adjust
selftests and samples include path to include libbpf now.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191008175942.1769476-6-andriin@fb.com
2019-10-08 23:16:03 +02:00
Toke Høiland-Jørgensen
a9eb048d56 libbpf: Add cscope and tags targets to Makefile
Using cscope and/or TAGS files for navigating the source code is useful.
Add simple targets to the Makefile to generate the index files for both
tools.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191004153444.1711278-1-toke@redhat.com
2019-10-05 18:24:56 -07:00
Andrii Nakryiko
c9e4c3010c libbpf: fix bpf_object__name() to actually return object name
bpf_object__name() was returning file path, not name. Fix this.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-10-05 18:09:48 -07:00
Andrii Nakryiko
2ce8450ef5 libbpf: add bpf_object__open_{file, mem} w/ extensible opts
Add new set of bpf_object__open APIs using new approach to optional
parameters extensibility allowing simpler ABI compatibility approach.

This patch demonstrates an approach to implementing libbpf APIs that
makes it easy to extend existing APIs with extra optional parameters in
such a way, that ABI compatibility is preserved without having to do
symbol versioning and generating lots of boilerplate code to handle it.
To facilitate succinct code for working with options, add OPTS_VALID,
OPTS_HAS, and OPTS_GET macros that hide all the NULL, size, and zero
checks.

Additionally, newly added libbpf APIs are encouraged to follow similar
pattern of having all mandatory parameters as formal function parameters
and always have optional (NULL-able) xxx_opts struct, which should
always have real struct size as a first field and the rest would be
optional parameters added over time, which tune the behavior of existing
API, if specified by user.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-10-05 18:09:47 -07:00
Andrii Nakryiko
5e61f27070 libbpf: stop enforcing kern_version, populate it for users
Kernel version enforcement for kprobes/kretprobes was removed from
5.0 kernel in 6c4fc209fc ("bpf: remove useless version check for prog load").
Since then, BPF programs were specifying SEC("version") just to please
libbpf. We should stop enforcing this in libbpf, if even kernel doesn't
care. Furthermore, libbpf now will pre-populate current kernel version
of the host system, in case we are still running on old kernel.

This patch also removes __bpf_object__open_xattr from libbpf.h, as
nothing in libbpf is relying on having it in that header. That function
was never exported as LIBBPF_API and even name suggests its internal
version. So this should be safe to remove, as it doesn't break ABI.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-10-05 18:09:47 -07:00
Andrii Nakryiko
03bd4773d8 libbpf: Bump current version to v0.0.6
New release cycle started, let's bump to v0.0.6 proactively.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20190930222503.519782-1-andriin@fb.com
2019-10-02 01:05:10 +02:00
Andrii Nakryiko
39529a9948 libbpf: Teach btf_dumper to emit stand-alone anonymous enum definitions
BTF-to-C converter previously skipped anonymous enums in an assumption
that those are embedded in struct's field definitions. This is not
always the case and a lot of kernel constants are defined as part of
anonymous enums. This change fixes the logic by eagerly marking all
types as either referenced by any other type or not. This is enough to
distinguish two classes of anonymous enums and emit previously omitted
enum definitions.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20190925203745.3173184-1-andriin@fb.com
2019-09-26 14:38:29 +02:00
Andrii Nakryiko
aef70a1f44 libbpf: fix false uninitialized variable warning
Some compilers emit warning for potential uninitialized next_id usage.
The code is correct, but control flow is too complicated for some
compilers to figure this out. Re-initialize next_id to satisfy
compiler.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-25 22:15:02 +02:00
Toke Høiland-Jørgensen
e0973a421c libbpf: Remove getsockopt() check for XDP_OPTIONS
The xsk_socket__create() function fails and returns an error if it cannot
get the XDP_OPTIONS through getsockopt(). However, support for XDP_OPTIONS
was not added until kernel 5.3, so this means that creating XSK sockets
always fails on older kernels.

Since the option is just used to set the zero-copy flag in the xsk struct,
and that flag is not really used for anything yet, just remove the
getsockopt() call until a proper use for it is introduced.

Suggested-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-09-19 14:22:18 +02:00
David S. Miller
1e46c09ec1 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
The following pull-request contains BPF updates for your *net-next* tree.

The main changes are:

1) Add the ability to use unaligned chunks in the AF_XDP umem. By
   relaxing where the chunks can be placed, it allows to use an
   arbitrary buffer size and place whenever there is a free
   address in the umem. Helps more seamless DPDK AF_XDP driver
   integration. Support for i40e, ixgbe and mlx5e, from Kevin and
   Maxim.

2) Addition of a wakeup flag for AF_XDP tx and fill rings so the
   application can wake up the kernel for rx/tx processing which
   avoids busy-spinning of the latter, useful when app and driver
   is located on the same core. Support for i40e, ixgbe and mlx5e,
   from Magnus and Maxim.

3) bpftool fixes for printf()-like functions so compiler can actually
   enforce checks, bpftool build system improvements for custom output
   directories, and addition of 'bpftool map freeze' command, from Quentin.

4) Support attaching/detaching XDP programs from 'bpftool net' command,
   from Daniel.

5) Automatic xskmap cleanup when AF_XDP socket is released, and several
   barrier/{read,write}_once fixes in AF_XDP code, from Björn.

6) Relicense of bpf_helpers.h/bpf_endian.h for future libbpf
   inclusion as well as libbpf versioning improvements, from Andrii.

7) Several new BPF kselftests for verifier precision tracking, from Alexei.

8) Several BPF kselftest fixes wrt endianess to run on s390x, from Ilya.

9) And more BPF kselftest improvements all over the place, from Stanislav.

10) Add simple BPF map op cache for nfp driver to batch dumps, from Jakub.

11) AF_XDP socket umem mapping improvements for 32bit archs, from Ivan.

12) Add BPF-to-BPF call and BTF line info support for s390x JIT, from Yauheni.

13) Small optimization in arm64 JIT to spare 1 insns for BPF_MOD, from Jerin.

14) Fix an error check in bpf_tcp_gen_syncookie() helper, from Petar.

15) Various minor fixes and cleanups, from Nathan, Masahiro, Masanari,
    Peter, Wei, Yue.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-09-06 16:49:17 +02:00
Kevin Laatz
10d30e3017 libbpf: add flags to umem config
This patch adds a 'flags' field to the umem_config and umem_reg structs.
This will allow for more options to be added for configuring umems.

The first use for the flags field is to add a flag for unaligned chunks
mode. These flags can either be user-provided or filled with a default.

Since we change the size of the xsk_umem_config struct, we need to version
the ABI. This patch includes the ABI versioning for xsk_umem__create. The
Makefile was also updated to handle multiple function versions in
check-abi.

Signed-off-by: Kevin Laatz <kevin.laatz@intel.com>
Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-31 01:08:26 +02:00
Ivan Khoronzhuk
71dd77fd4b libbpf: use LFS (_FILE_OFFSET_BITS) instead of direct mmap2 syscall
Drop __NR_mmap2 fork in flavor of LFS, that is _FILE_OFFSET_BITS=64
(glibc & bionic) / LARGEFILE64_SOURCE (for musl) decision. It allows
mmap() to use 64bit offset that is passed to mmap2 syscall. As result
pgoff is not truncated and no need to use direct access to mmap2 for
32 bits systems.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-21 14:31:17 +02:00
Quentin Monnet
09d7c2e32b libbpf: add bpf_btf_get_next_id() to cycle through BTF objects
Add an API function taking a BTF object id and providing the id of the
next BTF object in the kernel. This can be used to list all BTF objects
loaded on the system.

v2:
- Rebase on top of Andrii's changes regarding libbpf versioning.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-20 09:51:06 -07:00
Quentin Monnet
a6e130c420 libbpf: refactor bpf_*_get_next_id() functions
In preparation for the introduction of a similar function for retrieving
the id of the next BTF object, consolidate the code from
bpf_prog_get_next_id() and bpf_map_get_next_id() in libbpf.

Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-20 09:51:06 -07:00
David S. Miller
446bf64b61 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge conflict of mlx5 resolved using instructions in merge
commit 9566e650bf.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-19 11:54:03 -07:00
Magnus Karlsson
a4500432c2 libbpf: add support for need_wakeup flag in AF_XDP part
This commit adds support for the new need_wakeup flag in AF_XDP. The
xsk_socket__create function is updated to handle this and a new
function is introduced called xsk_ring_prod__needs_wakeup(). This
function can be used by the application to check if Rx and/or Tx
processing needs to be explicitly woken up.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-17 23:07:32 +02:00
Andrii Nakryiko
dadb81d0af libbpf: make libbpf.map source of truth for libbpf version
Currently libbpf version is specified in 2 places: libbpf.map and
Makefile. They easily get out of sync and it's very easy to update one,
but forget to update another one. In addition, Github projection of
libbpf has to maintain its own version which has to be remembered to be
kept in sync manually, which is very error-prone approach.

This patch makes libbpf.map a source of truth for libbpf version and
uses shell invocation to parse out correct full and major libbpf version
to use during build. Now we need to make sure that once new release
cycle starts, we need to add (initially) empty section to libbpf.map
with correct latest version.

This also will make it possible to keep Github projection consistent
with kernel sources version of libbpf by adopting similar parsing of
version from libbpf.map.

v2->v3:
- grep -o + sort -rV (Andrey);

v1->v2:
- eager version vars evaluation (Jakub);
- simplified version regex (Andrey);

Cc: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-15 17:03:26 -07:00
Jakub Kicinski
708852dcac Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
The following pull-request contains BPF updates for your *net-next* tree.

There is a small merge conflict in libbpf (Cc Andrii so he's in the loop
as well):

        for (i = 1; i <= btf__get_nr_types(btf); i++) {
                t = (struct btf_type *)btf__type_by_id(btf, i);

                if (!has_datasec && btf_is_var(t)) {
                        /* replace VAR with INT */
                        t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
  <<<<<<< HEAD
                        /*
                         * using size = 1 is the safest choice, 4 will be too
                         * big and cause kernel BTF validation failure if
                         * original variable took less than 4 bytes
                         */
                        t->size = 1;
                        *(int *)(t+1) = BTF_INT_ENC(0, 0, 8);
                } else if (!has_datasec && kind == BTF_KIND_DATASEC) {
  =======
                        t->size = sizeof(int);
                        *(int *)(t + 1) = BTF_INT_ENC(0, 0, 32);
                } else if (!has_datasec && btf_is_datasec(t)) {
  >>>>>>> 72ef80b5ee
                        /* replace DATASEC with STRUCT */

Conflict is between the two commits 1d4126c4e1 ("libbpf: sanitize VAR to
conservative 1-byte INT") and b03bc6853c ("libbpf: convert libbpf code to
use new btf helpers"), so we need to pick the sanitation fixup as well as
use the new btf_is_datasec() helper and the whitespace cleanup. Looks like
the following:

  [...]
                if (!has_datasec && btf_is_var(t)) {
                        /* replace VAR with INT */
                        t->info = BTF_INFO_ENC(BTF_KIND_INT, 0, 0);
                        /*
                         * using size = 1 is the safest choice, 4 will be too
                         * big and cause kernel BTF validation failure if
                         * original variable took less than 4 bytes
                         */
                        t->size = 1;
                        *(int *)(t + 1) = BTF_INT_ENC(0, 0, 8);
                } else if (!has_datasec && btf_is_datasec(t)) {
                        /* replace DATASEC with STRUCT */
  [...]

The main changes are:

1) Addition of core parts of compile once - run everywhere (co-re) effort,
   that is, relocation of fields offsets in libbpf as well as exposure of
   kernel's own BTF via sysfs and loading through libbpf, from Andrii.

   More info on co-re: http://vger.kernel.org/bpfconf2019.html#session-2
   and http://vger.kernel.org/lpc-bpf2018.html#session-2

2) Enable passing input flags to the BPF flow dissector to customize parsing
   and allowing it to stop early similar to the C based one, from Stanislav.

3) Add a BPF helper function that allows generating SYN cookies from XDP and
   tc BPF, from Petar.

4) Add devmap hash-based map type for more flexibility in device lookup for
   redirects, from Toke.

5) Improvements to XDP forwarding sample code now utilizing recently enabled
   devmap lookups, from Jesper.

6) Add support for reporting the effective cgroup progs in bpftool, from Jakub
   and Takshak.

7) Fix reading kernel config from bpftool via /proc/config.gz, from Peter.

8) Fix AF_XDP umem pages mapping for 32 bit architectures, from Ivan.

9) Follow-up to add two more BPF loop tests for the selftest suite, from Alexei.

10) Add perf event output helper also for other skb-based program types, from Allan.

11) Fix a co-re related compilation error in selftests, from Yonghong.
====================

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-08-13 16:24:57 -07:00
Andrii Nakryiko
a1916a153c libbpf: attempt to load kernel BTF from sysfs first
Add support for loading kernel BTF from sysfs (/sys/kernel/btf/vmlinux)
as a target BTF. Also extend the list of on disk search paths for
vmlinux ELF image with entries that perf is searching for.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-13 23:19:42 +02:00
David S. Miller
9481382b36 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2019-08-11

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) x64 JIT code generation fix for backward-jumps to 1st insn, from Alexei.

2) Fix buggy multi-closing of BTF file descriptor in libbpf, from Andrii.

3) Fix libbpf_num_possible_cpus() to make it thread safe, from Takshak.

4) Fix bpftool to dump an error if pinning fails, from Jakub.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-11 14:49:34 -07:00
Andrii Nakryiko
ddc7c30426 libbpf: implement BPF CO-RE offset relocation algorithm
This patch implements the core logic for BPF CO-RE offsets relocations.
Every instruction that needs to be relocated has corresponding
bpf_offset_reloc as part of BTF.ext. Relocations are performed by trying
to match recorded "local" relocation spec against potentially many
compatible "target" types, creating corresponding spec. Details of the
algorithm are noted in corresponding comments in the code.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Andrii Nakryiko
4cedc0dad9 libbpf: add .BTF.ext offset relocation section loading
Add support for BPF CO-RE offset relocations. Add section/record
iteration macros for .BTF.ext. These macro are useful for iterating over
each .BTF.ext record, either for dumping out contents or later for BPF
CO-RE relocation handling.

To enable other parts of libbpf to work with .BTF.ext contents, moved
a bunch of type definitions into libbpf_internal.h.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Andrii Nakryiko
b03bc6853c libbpf: convert libbpf code to use new btf helpers
Simplify code by relying on newly added BTF helper functions.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Andrii Nakryiko
ef20a9b27c libbpf: add helpers for working with BTF types
Add lots of frequently used helpers that simplify working with BTF
types.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-07 14:43:49 -07:00
Linus Torvalds
33920f1ec5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "Yeah I should have sent a pull request last week, so there is a lot
  more here than usual:

   1) Fix memory leak in ebtables compat code, from Wenwen Wang.

   2) Several kTLS bug fixes from Jakub Kicinski (circular close on
      disconnect etc.)

   3) Force slave speed check on link state recovery in bonding 802.3ad
      mode, from Thomas Falcon.

   4) Clear RX descriptor bits before assigning buffers to them in
      stmmac, from Jose Abreu.

   5) Several missing of_node_put() calls, mostly wrt. for_each_*() OF
      loops, from Nishka Dasgupta.

   6) Double kfree_skb() in peak_usb can driver, from Stephane Grosjean.

   7) Need to hold sock across skb->destructor invocation, from Cong
      Wang.

   8) IP header length needs to be validated in ipip tunnel xmit, from
      Haishuang Yan.

   9) Use after free in ip6 tunnel driver, also from Haishuang Yan.

  10) Do not use MSI interrupts on r8169 chips before RTL8168d, from
      Heiner Kallweit.

  11) Upon bridge device init failure, we need to delete the local fdb.
      From Nikolay Aleksandrov.

  12) Handle erros from of_get_mac_address() properly in stmmac, from
      Martin Blumenstingl.

  13) Handle concurrent rename vs. dump in netfilter ipset, from Jozsef
      Kadlecsik.

  14) Setting NETIF_F_LLTX on mac80211 causes complete breakage with
      some devices, so revert. From Johannes Berg.

  15) Fix deadlock in rxrpc, from David Howells.

  16) Fix Kconfig deps of enetc driver, we must have PHYLIB. From Yue
      Haibing.

  17) Fix mvpp2 crash on module removal, from Matteo Croce.

  18) Fix race in genphy_update_link, from Heiner Kallweit.

  19) bpf_xdp_adjust_head() stopped working with generic XDP when we
      fixes generic XDP to support stacked devices properly, fix from
      Jesper Dangaard Brouer.

  20) Unbalanced RCU locking in rt6_update_exception_stamp_rt(), from
      David Ahern.

  21) Several memory leaks in new sja1105 driver, from Vladimir Oltean"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (214 commits)
  net: dsa: sja1105: Fix memory leak on meta state machine error path
  net: dsa: sja1105: Fix memory leak on meta state machine normal path
  net: dsa: sja1105: Really fix panic on unregistering PTP clock
  net: dsa: sja1105: Use the LOCKEDS bit for SJA1105 E/T as well
  net: dsa: sja1105: Fix broken learning with vlan_filtering disabled
  net: dsa: qca8k: Add of_node_put() in qca8k_setup_mdio_bus()
  net: sched: sample: allow accessing psample_group with rtnl
  net: sched: police: allow accessing police->params with rtnl
  net: hisilicon: Fix dma_map_single failed on arm64
  net: hisilicon: fix hip04-xmit never return TX_BUSY
  net: hisilicon: make hip04_tx_reclaim non-reentrant
  tc-testing: updated vlan action tests with batch create/delete
  net sched: update vlan action for batched events operations
  net: stmmac: tc: Do not return a fragment entry
  net: stmmac: Fix issues when number of Queues >= 4
  net: stmmac: xgmac: Fix XGMAC selftests
  be2net: disable bh with spin_lock in be_process_mcc
  net: cxgb3_main: Fix a resource leak in a error path in 'init_one()'
  net: ethernet: sun4i-emac: Support phy-handle property for finding PHYs
  net: bridge: move default pvid init/deinit to NETDEV_REGISTER/UNREGISTER
  ...
2019-08-06 17:11:59 -07:00
Andrii Nakryiko
3415ec643e libbpf: set BTF FD for prog only when there is supported .BTF.ext data
5d01ab7bac ("libbpf: fix erroneous multi-closing of BTF FD")
introduced backwards-compatibility issue, manifesting itself as -E2BIG
error returned on program load due to unknown non-zero btf_fd attribute
value for BPF_PROG_LOAD sys_bpf() sub-command.

This patch fixes bug by ensuring that we only ever associate BTF FD with
program if there is a BTF.ext data that was successfully loaded into
kernel, which automatically means kernel supports func_info/line_info
and associated BTF FD for progs (checked and ensured also by BTF
sanitization code).

Fixes: 5d01ab7bac ("libbpf: fix erroneous multi-closing of BTF FD")
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-01 13:10:45 -07:00
Takshak Chahande
56fbc24116 libbpf : make libbpf_num_possible_cpus function thread safe
Having static variable `cpus` in libbpf_num_possible_cpus function
without guarding it with mutex makes this function thread-unsafe.

If multiple threads accessing this function, in the current form; it
leads to incrementing the static variable value `cpus` in the multiple
of total available CPUs.

Used local stack variable to calculate the number of possible CPUs and
then updated the static variable using WRITE_ONCE().

Changes since v1:
 * added stack variable to calculate cpus
 * serialized static variable update using WRITE_ONCE()
 * fixed Fixes tag

Fixes: 6446b31555 ("bpf: add a new API libbpf_num_possible_cpus()")
Signed-off-by: Takshak Chahande <ctakshak@fb.com>
Acked-by: Andrey Ignatov <rdna@fb.com>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-31 20:35:19 -07:00
Toke Høiland-Jørgensen
e42346192c tools/libbpf_probes: Add new devmap_hash type
This adds the definition for BPF_MAP_TYPE_DEVMAP_HASH to libbpf_probes.c in
tools/lib/bpf.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-29 13:50:48 -07:00
Andrii Nakryiko
8aa259b10a libbpf: fix missing __WORDSIZE definition
hashmap.h depends on __WORDSIZE being defined. It is defined by
glibc/musl in different headers. It's an explicit goal for musl to be
"non-detectable" at compilation time, so instead include glibc header if
glibc is explicitly detected and fall back to musl header otherwise.

Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Fixes: e3b9242240 ("libbpf: add resizable non-thread safe internal hashmap")
Link: https://lkml.kernel.org/r/20190718173021.2418606-1-andriin@fb.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-07-29 10:18:08 -03:00
Andrii Nakryiko
e87fd8bae4 libbpf: return previous print callback from libbpf_set_print
By returning previously set print callback from libbpf_set_print, it's
possible to restore it, eventually. This is useful when running many
independent test with one default print function, but overriding log
verbosity for particular subset of tests.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-27 22:36:19 -07:00
Andrii Nakryiko
5d01ab7bac libbpf: fix erroneous multi-closing of BTF FD
Libbpf stores associated BTF FD per each instance of bpf_program. When
program is unloaded, that FD is closed. This is wrong, because leads to
a race and possibly closing of unrelated files, if application
simultaneously opens new files while bpf_programs are unloaded.

It's also unnecessary, because struct btf "owns" that FD, and
btf__free(), called from bpf_object__close() will close it. Thus the fix
is to never have per-program BTF FD and fetch it from obj->btf, when
necessary.

Fixes: 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
Reported-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-26 17:23:16 -07:00
Andrii Nakryiko
cb8ffde569 libbpf: silence GCC8 warning about string truncation
Despite a proper NULL-termination after strncpy(..., ..., IFNAMSIZ - 1),
GCC8 still complains about *expected* string truncation:

  xsk.c:330:2: error: 'strncpy' output may be truncated copying 15 bytes
  from a string of length 15 [-Werror=stringop-truncation]
    strncpy(ifr.ifr_name, xsk->ifname, IFNAMSIZ - 1);

This patch gets rid of the issue altogether by using memcpy instead.
There is no performance regression, as strncpy will still copy and fill
all of the bytes anyway.

v1->v2:
- rebase against bpf tree.

Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-25 10:13:31 -07:00
Andrii Nakryiko
f2a3e4e95f libbpf: provide more helpful message on uninitialized global var
When BPF program defines uninitialized global variable, it's put into
a special COMMON section. Libbpf will reject such programs, but will
provide very unhelpful message with garbage-looking section index.

This patch detects special section cases and gives more explicit error
message.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-23 15:59:12 -07:00
Ilya Maximets
decb705e01 libbpf: fix using uninitialized ioctl results
'channels.max_combined' initialized only on ioctl success and
errno is only valid on ioctl failure.

The code doesn't produce any runtime issues, but makes memory
sanitizers angry:

 Conditional jump or move depends on uninitialised value(s)
    at 0x55C056F: xsk_get_max_queues (xsk.c:336)
    by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
    by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
    by 0x55C0E57: xsk_socket__create (xsk.c:601)
  Uninitialised value was created by a stack allocation
    at 0x55C04CD: xsk_get_max_queues (xsk.c:318)

Additionally fixed warning on uninitialized bytes in ioctl arguments:

 Syscall param ioctl(SIOCETHTOOL) points to uninitialised byte(s)
    at 0x648D45B: ioctl (in /usr/lib64/libc-2.28.so)
    by 0x55C0546: xsk_get_max_queues (xsk.c:330)
    by 0x55C05B2: xsk_create_bpf_maps (xsk.c:354)
    by 0x55C089F: xsk_setup_xdp_prog (xsk.c:447)
    by 0x55C0E57: xsk_socket__create (xsk.c:601)
  Address 0x1ffefff378 is on thread 1's stack
  in frame #1, created by xsk_get_max_queues (xsk.c:318)
  Uninitialised value was created by a stack allocation
    at 0x55C04CD: xsk_get_max_queues (xsk.c:318)

CC: Magnus Karlsson <magnus.karlsson@intel.com>
Fixes: 1cad078842 ("libbpf: add support for using AF_XDP sockets")
Signed-off-by: Ilya Maximets <i.maximets@samsung.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-07-23 15:14:35 -07:00
Arnaldo Carvalho de Melo
4be6e05c4d libbpf: Avoid designated initializers for unnamed union members
As it fails to build in some systems with:

  libbpf.c: In function 'perf_buffer__new':
  libbpf.c:4515: error: unknown field 'sample_period' specified in initializer
  libbpf.c:4516: error: unknown field 'wakeup_events' specified in initializer

Doing as:

    attr.sample_period = 1;

I.e. not as a designated initializer makes it build everywhere.

Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: fb84b82246 ("libbpf: add perf buffer API")
Link: https://lkml.kernel.org/n/tip-hnlmch8qit1ieksfppmr32si@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-22 16:14:43 +02:00
Arnaldo Carvalho de Melo
cdb2f92071 libbpf: Fix endianness macro usage for some compilers
Using endian.h and its endianness macros makes this code build in a
wider range of compilers, as some don't have those macros
(__BYTE_ORDER__, __ORDER_LITTLE_ENDIAN__, __ORDER_BIG_ENDIAN__),
so use instead endian.h's macros (__BYTE_ORDER, __LITTLE_ENDIAN,
__BIG_ENDIAN) which makes this code even shorter :-)

Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 12ef5634a8 ("libbpf: simplify endianness check")
Fixes: e6c64855fd ("libbpf: add btf__parse_elf API to load .BTF and .BTF.ext")
Link: https://lkml.kernel.org/n/tip-eep5n8vgwcdphw3uc058k03u@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-07-22 16:14:43 +02:00