Commit Graph

1266 Commits

Author SHA1 Message Date
Toke Høiland-Jørgensen
dc3a2d2547 libbpf: Print hint about ulimit when getting permission denied error
Probably the single most common error newcomers to XDP are stumped by is
the 'permission denied' error they get when trying to load their program
and 'ulimit -l' is set too low. For examples, see [0], [1].

Since the error code is UAPI, we can't change that. Instead, this patch
adds a few heuristics in libbpf and outputs an additional hint if they are
met: If an EPERM is returned on map create or program load, and geteuid()
shows we are root, and the current RLIMIT_MEMLOCK is not infinity, we
output a hint about raising 'ulimit -l' as an additional log line.

[0] https://marc.info/?l=xdp-newbies&m=157043612505624&w=2
[1] https://github.com/xdp-project/xdp-tutorial/issues/86

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191216181204.724953-1-toke@redhat.com
2019-12-16 14:52:34 -08:00
Sudip Mukherjee
c09982f8e2 libtraceevent: Allow custom libdir path
When I use prefix=/usr and try to install libtraceevent in my laptop it
tries to install in /usr/lib64. I am not having any folder as /usr/lib64
and also the debian policy doesnot allow installing in /usr/lib64. It
should be in /usr/lib/x86_64-linux-gnu/.

Quote: No package for a 64 bit architecture may install files in
	/usr/lib64/ or in a subdirectory of it.

ref: https://www.debian.org/doc/debian-policy/ch-opersys.html

Make it more flexible by allowing to mention libdir_relative while
installing so that distros can mention the path according to their
policy or use the default one.

Signed-off-by: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191207111440.6574-1-sudipm.mukherjee@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-12-16 13:40:26 -03:00
Prashant Bhole
a79ac2d103 libbpf: Fix build by renaming variables
In btf__align_of() variable name 't' is shadowed by inner block
declaration of another variable with same name. Patch renames
variables in order to fix it.

  CC       sharedobjs/btf.o
btf.c: In function ‘btf__align_of’:
btf.c:303:21: error: declaration of ‘t’ shadows a previous local [-Werror=shadow]
  303 |   int i, align = 1, t;
      |                     ^
btf.c:283:25: note: shadowed declaration is here
  283 |  const struct btf_type *t = btf__type_by_id(btf, id);
      |

Fixes: 3d208f4ca1 ("libbpf: Expose btf__align_of() API")
Signed-off-by: Prashant Bhole <prashantbhole.linux@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191216082738.28421-1-prashantbhole.linux@gmail.com
2019-12-16 14:14:16 +01:00
Andrii Nakryiko
1b484b301c libbpf: Support flexible arrays in CO-RE
Some data stuctures in kernel are defined with either zero-sized array or
flexible (dimensionless) array at the end of a struct. Actual data of such
array follows in memory immediately after the end of that struct, forming its
variable-sized "body" of elements. Support such access pattern in CO-RE
relocation handling.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191215070844.1014385-2-andriin@fb.com
2019-12-15 16:53:50 -08:00
Andrii Nakryiko
2ad97d473d bpftool: Generate externs datasec in BPF skeleton
Add support for generation of mmap()-ed read-only view of libbpf-provided
extern variables. As externs are not supposed to be provided by user code
(that's what .data, .bss, and .rodata is for), don't mmap() it initially. Only
after skeleton load is performed, map .extern contents as read-only memory.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014710.3449601-4-andriin@fb.com
2019-12-15 16:41:12 -08:00
Andrii Nakryiko
166750bc1d libbpf: Support libbpf-provided extern variables
Add support for extern variables, provided to BPF program by libbpf. Currently
the following extern variables are supported:
  - LINUX_KERNEL_VERSION; version of a kernel in which BPF program is
    executing, follows KERNEL_VERSION() macro convention, can be 4- and 8-byte
    long;
  - CONFIG_xxx values; a set of values of actual kernel config. Tristate,
    boolean, strings, and integer values are supported.

Set of possible values is determined by declared type of extern variable.
Supported types of variables are:
- Tristate values. Are represented as `enum libbpf_tristate`. Accepted values
  are **strictly** 'y', 'n', or 'm', which are represented as TRI_YES, TRI_NO,
  or TRI_MODULE, respectively.
- Boolean values. Are represented as bool (_Bool) types. Accepted values are
  'y' and 'n' only, turning into true/false values, respectively.
- Single-character values. Can be used both as a substritute for
  bool/tristate, or as a small-range integer:
  - 'y'/'n'/'m' are represented as is, as characters 'y', 'n', or 'm';
  - integers in a range [-128, 127] or [0, 255] (depending on signedness of
    char in target architecture) are recognized and represented with
    respective values of char type.
- Strings. String values are declared as fixed-length char arrays. String of
  up to that length will be accepted and put in first N bytes of char array,
  with the rest of bytes zeroed out. If config string value is longer than
  space alloted, it will be truncated and warning message emitted. Char array
  is always zero terminated. String literals in config have to be enclosed in
  double quotes, just like C-style string literals.
- Integers. 8-, 16-, 32-, and 64-bit integers are supported, both signed and
  unsigned variants. Libbpf enforces parsed config value to be in the
  supported range of corresponding integer type. Integers values in config can
  be:
  - decimal integers, with optional + and - signs;
  - hexadecimal integers, prefixed with 0x or 0X;
  - octal integers, starting with 0.

Config file itself is searched in /boot/config-$(uname -r) location with
fallback to /proc/config.gz, unless config path is specified explicitly
through bpf_object_open_opts' kernel_config_path option. Both gzipped and
plain text formats are supported. Libbpf adds explicit dependency on zlib
because of this, but this shouldn't be a problem, given libelf already depends
on zlib.

All detected extern variables, are put into a separate .extern internal map.
It, similarly to .rodata map, is marked as read-only from BPF program side, as
well as is frozen on load. This allows BPF verifier to track extern values as
constants and perform enhanced branch prediction and dead code elimination.
This can be relied upon for doing kernel version/feature detection and using
potentially unsupported field relocations or BPF helpers in a CO-RE-based BPF
program, while still having a single version of BPF program running on old and
new kernels. Selftests are validating this explicitly for unexisting BPF
helper.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014710.3449601-3-andriin@fb.com
2019-12-15 16:41:12 -08:00
Andrii Nakryiko
ac9d138963 libbpf: Extract internal map names into constants
Instead of duplicating string literals, keep them in one place and consistent.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014710.3449601-2-andriin@fb.com
2019-12-15 16:41:12 -08:00
Andrii Nakryiko
d66562fba1 libbpf: Add BPF object skeleton support
Add new set of APIs, allowing to open/load/attach BPF object through BPF
object skeleton, generated by bpftool for a specific BPF object file. All the
xxx_skeleton() APIs wrap up corresponding bpf_object_xxx() APIs, but
additionally also automate map/program lookups by name, global data
initialization and mmap()-ing, etc.  All this greatly improves and simplifies
userspace usability of working with BPF programs. See follow up patches for
examples.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-13-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
3f51935314 libbpf: Reduce log level of supported section names dump
It's quite spammy. And now that bpf_object__open() is trying to determine
program type from its section name, we are getting these verbose messages all
the time. Reduce their log level to DEBUG.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-12-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
13acb508ae libbpf: Postpone BTF ID finding for TRACING programs to load phase
Move BTF ID determination for BPF_PROG_TYPE_TRACING programs to a load phase.
Performing it at open step is inconvenient, because it prevents BPF skeleton
generation on older host kernel, which doesn't contain BTF_KIND_FUNCs
information in vmlinux BTF. This is a common set up, though, when, e.g.,
selftests are compiled on older host kernel, but the test program itself is
executed in qemu VM with bleeding edge kernel. Having this BTF searching
performed at load time allows to successfully use bpf_object__open() for
codegen and inspection of BPF object file.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-11-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
eba9c5f498 libbpf: Refactor global data map initialization
Refactor global data map initialization to use anonymous mmap()-ed memory
instead of malloc()-ed one. This allows to do a transparent re-mmap()-ing of
already existing memory address to point to BPF map's memory after
bpf_object__load() step (done in follow up patch). This choreographed setup
allows to have a nice and unsurprising way to pre-initialize read-only (and
r/w as well) maps by user and after BPF map creation keep working with
mmap()-ed contents of this map. All in a way that doesn't require user code to
update any pointers: the illusion of working with memory contents is preserved
before and after actual BPF map instantiation.

Selftests and runqslower example demonstrate this feature in follow up patches.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-10-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
01af3bf067 libbpf: Expose BPF program's function name
Add APIs to get BPF program function name, as opposed to bpf_program__title(),
which returns BPF program function's section name. Function name has a benefit
of being a valid C identifier and uniquely identifies a specific BPF program,
while section name can be duplicated across multiple independent BPF programs.

Add also bpf_object__find_program_by_name(), similar to
bpf_object__find_program_by_title(), to facilitate looking up BPF programs by
their C function names.

Convert one of selftests to new API for look up.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-9-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
9f81654eeb libbpf: Expose BTF-to-C type declaration emitting API
Expose API that allows to emit type declaration and field/variable definition
(if optional field name is specified) in valid C syntax for any provided BTF
type. This is going to be used by bpftool when emitting data section layout as
a struct. As part of making this API useful in a stand-alone fashion, move
initialization of some of the internal btf_dump state to earlier phase.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-8-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
3d208f4ca1 libbpf: Expose btf__align_of() API
Expose BTF API that calculates type alignment requirements.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-7-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
544402d4b4 libbpf: Extract common user-facing helpers
LIBBPF_API and DECLARE_LIBBPF_OPTS are needed in many public libbpf API
headers. Extract them into libbpf_common.h to avoid unnecessary
interdependency between btf.h, libbpf.h, and bpf.h or code duplication.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-6-andriin@fb.com
2019-12-15 15:58:05 -08:00
Andrii Nakryiko
917f6b7b07 libbpf: Add BPF_EMBED_OBJ macro for embedding BPF .o files
Add a convenience macro BPF_EMBED_OBJ, which allows to embed other files
(typically used to embed BPF .o files) into a hosting userspace programs. To
C program it is exposed as struct bpf_embed_data, containing a pointer to
raw data and its size in bytes.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-5-andriin@fb.com
2019-12-15 15:58:04 -08:00
Andrii Nakryiko
612d05be25 libbpf: Move non-public APIs from libbpf.h to libbpf_internal.h
Few libbpf APIs are not public but currently exposed through libbpf.h to be
used by bpftool. Move them to libbpf_internal.h, where intent of being
non-stable and non-public is much more obvious.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-4-andriin@fb.com
2019-12-15 15:58:04 -08:00
Andrii Nakryiko
d7a18ea7e8 libbpf: Add generic bpf_program__attach()
Generalize BPF program attaching and allow libbpf to auto-detect type (and
extra parameters, where applicable) and attach supported BPF program types
based on program sections. Currently this is supported for:
- kprobe/kretprobe;
- tracepoint;
- raw tracepoint;
- tracing programs (typed raw TP/fentry/fexit).

More types support can be trivially added within this framework.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-3-andriin@fb.com
2019-12-15 15:58:04 -08:00
Andrii Nakryiko
0d13bfce02 libbpf: Don't require root for bpf_object__open()
Reorganize bpf_object__open and bpf_object__load steps such that
bpf_object__open doesn't need root access. This was previously done for
feature probing and BTF sanitization. This doesn't have to happen on open,
though, so move all those steps into the load phase.

This is important, because it makes it possible for tools like bpftool, to
just open BPF object file and inspect their contents: programs, maps, BTF,
etc. For such operations it is prohibitive to require root access. On the
other hand, there is a lot of custom libbpf logic in those steps, so its best
avoided for tools to reimplement all that on their own.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191214014341.3442258-2-andriin@fb.com
2019-12-15 15:58:04 -08:00
Thadeu Lima de Souza Cascardo
aa915931ac libbpf: Fix readelf output parsing for Fedora
Fedora binutils has been patched to show "other info" for a symbol at the
end of the line. This was done in order to support unmaintained scripts
that would break with the extra info. [1]

[1] b8265c46f7

This in turn has been done to fix the build of ruby, because of checksec.
[2] Thanks Michael Ellerman for the pointer.

[2] https://bugzilla.redhat.com/show_bug.cgi?id=1479302

As libbpf Makefile is not unmaintained, we can simply deal with either
output format, by just removing the "other info" field, as it always comes
inside brackets.

Fixes: 3464afdf11 (libbpf: Fix readelf output parsing on powerpc with recent binutils)
Reported-by: Justin Forbes <jmforbes@linuxtx.org>
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Link: https://lore.kernel.org/bpf/20191213101114.GA3986@calabresa
2019-12-15 09:40:58 -08:00
Andrii Nakryiko
783b8f01f5 libbpf: Don't attach perf_buffer to offline/missing CPUs
It's quite common on some systems to have more CPUs enlisted as "possible",
than there are (and could ever be) present/online CPUs. In such cases,
perf_buffer creationg will fail due to inability to create perf event on
missing CPU with error like this:

libbpf: failed to open perf buffer event on cpu #16: No such device

This patch fixes the logic of perf_buffer__new() to ignore CPUs that are
missing or currently offline. In rare cases where user explicitly listed
specific CPUs to connect to, behavior is unchanged: libbpf will try to open
perf event buffer on specified CPU(s) anyways.

Fixes: fb84b82246 ("libbpf: add perf buffer API")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191212013609.1691168-1-andriin@fb.com
2019-12-13 13:00:09 -08:00
Andrii Nakryiko
6803ee25f0 libbpf: Extract and generalize CPU mask parsing logic
This logic is re-used for parsing a set of online CPUs. Having it as an
isolated piece of code working with input string makes it conveninent to test
this logic as well. While refactoring, also improve the robustness of original
implementation.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191212013548.1690564-1-andriin@fb.com
2019-12-13 12:58:51 -08:00
Jakub Sitnicki
67d69ccdf3 libbpf: Recognize SK_REUSEPORT programs from section name
Allow loading BPF object files that contain SK_REUSEPORT programs without
having to manually set the program type before load if the the section name
is set to "sk_reuseport".

Makes user-space code needed to load SK_REUSEPORT BPF program more concise.

Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191212102259.418536-2-jakub@cloudflare.com
2019-12-13 12:38:00 -08:00
Andrii Nakryiko
679152d3a3 libbpf: Fix printf compilation warnings on ppc64le arch
On ppc64le __u64 and __s64 are defined as long int and unsigned long int,
respectively. This causes compiler to emit warning when %lld/%llu are used to
printf 64-bit numbers. Fix this by casting to size_t/ssize_t with %zu and %zd
format specifiers, respectively.

v1->v2:
- use size_t/ssize_t instead of custom typedefs (Martin).

Fixes: 1f8e2bcb2c ("libbpf: Refactor relocation handling")
Fixes: abd29c9314 ("libbpf: allow specifying map definitions using BTF")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191212171918.638010-1-andriin@fb.com
2019-12-12 13:47:24 -08:00
Andrii Nakryiko
09c4708d3c libbpf: Bump libpf current version to v0.0.7
New development cycles starts, bump to v0.0.7 proactively.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20191209224022.3544519-1-andriin@fb.com
2019-12-11 14:50:37 +01:00
Arnaldo Carvalho de Melo
761bfc33dd Merge remote-tracking branch 'torvalds/master' into perf/urgent
To pick up BPF fixes to allow a clean 'make -C tools/perf build-test':

  7c3977d1e8 libbpf: Fix sym->st_value print on 32-bit arches
  1fd450f992 libbpf: Fix up generation of bpf_helper_defs.h

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-12-11 09:58:16 -03:00
Stanislav Fomichev
6bf6affe18 selftests/bpf: Bring back c++ include/link test
Commit 5c26f9a783 ("libbpf: Don't use cxx to test_libpf target")
converted existing c++ test to c. We still want to include and
link against libbpf from c++ code, so reinstate this test back,
this time in a form of a selftest with a clear comment about
its purpose.

v2:
* -lelf -> $(LDLIBS) (Andrii Nakryiko)

Fixes: 5c26f9a783 ("libbpf: Don't use cxx to test_libpf target")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191202215931.248178-1-sdf@google.com
2019-12-04 17:57:55 -08:00
Sudip Mukherjee
15b3904f8e libtraceevent: Copy pkg-config file to output folder when using O=
When we use 'O=' with make to build libtraceevent in a separate folder
it still copies 'libtraceevent.pc' to its source folder. Modify the
Makefile so that it uses the output folder to copy the pkg-config file
and install from there.

Signed-off-by: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191115113610.21493-2-sudipm.mukherjee@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-12-02 21:58:20 -03:00
Sudip Mukherjee
587db8ebda libtraceevent: Fix lib installation with O=
When we use 'O=' with make to build libtraceevent in a separate folder
it fails to install libtraceevent.a and libtraceevent.so.1.1.0 with the
error:

  INSTALL  /home/sudip/linux/obj-trace/libtraceevent.a
  INSTALL  /home/sudip/linux/obj-trace/libtraceevent.so.1.1.0

  cp: cannot stat 'libtraceevent.a': No such file or directory
  Makefile:225: recipe for target 'install_lib' failed
  make: *** [install_lib] Error 1

I used the command:

  make O=../../../obj-trace DESTDIR=~/test prefix==/usr  install

It turns out libtraceevent Makefile, even though it builds in a separate
folder, searches for libtraceevent.a and libtraceevent.so.1.1.0 in its
source folder.

So, add the 'OUTPUT' prefix to the source path so that 'make' looks for
the files in the correct place.

Signed-off-by: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191115113610.21493-1-sudipm.mukherjee@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-12-02 21:58:20 -03:00
David S. Miller
734c7022ad Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:

====================
pull-request: bpf 2019-12-02

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

We've added 10 non-merge commits during the last 6 day(s) which contain
a total of 10 files changed, 60 insertions(+), 51 deletions(-).

The main changes are:

1) Fix vmlinux BTF generation for binutils pre v2.25, from Stanislav Fomichev.

2) Fix libbpf global variable relocation to take symbol's st_value offset
   into account, from Andrii Nakryiko.

3) Fix libbpf build on powerpc where check_abi target fails due to different
   readelf output format, from Aurelien Jarno.

4) Don't set BPF insns RO for the case when they are JITed in order to avoid
   fragmenting the direct map, from Daniel Borkmann.

5) Fix static checker warning in btf_distill_func_proto() as well as a build
   error due to empty enum when BPF is compiled out, from Alexei Starovoitov.

6) Fix up generation of bpf_helper_defs.h for perf, from Arnaldo Carvalho de Melo.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-02 10:50:29 -08:00
Aurelien Jarno
3464afdf11 libbpf: Fix readelf output parsing on powerpc with recent binutils
On powerpc with recent versions of binutils, readelf outputs an extra
field when dumping the symbols of an object file. For example:

    35: 0000000000000838    96 FUNC    LOCAL  DEFAULT [<localentry>: 8]     1 btf_is_struct

The extra "[<localentry>: 8]" prevents the GLOBAL_SYM_COUNT variable to
be computed correctly and causes the check_abi target to fail.

Fix that by looking for the symbol name in the last field instead of the
8th one. This way it should also cope with future extra fields.

Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/bpf/20191201195728.4161537-1-aurelien@aurel32.net
2019-12-02 10:31:54 +01:00
Alexei Starovoitov
7c3977d1e8 libbpf: Fix sym->st_value print on 32-bit arches
The st_value field is a 64-bit value and causing this error on 32-bit arches:

In file included from libbpf.c:52:
libbpf.c: In function 'bpf_program__record_reloc':
libbpf_internal.h:59:22: error: format '%lu' expects argument of type 'long unsigned int', but argument 3 has type 'Elf64_Addr' {aka 'const long long unsigned int'} [-Werror=format=]

Fix it with (__u64) cast.

Fixes: 1f8e2bcb2c ("libbpf: Refactor relocation handling")
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-11-27 17:46:56 -08:00
Arnaldo Carvalho de Melo
1fd450f992 libbpf: Fix up generation of bpf_helper_defs.h
$ make -C tools/perf build-test

does, ends up with these two problems:

  make[3]: *** No rule to make target '/tmp/tmp.zq13cHILGB/perf-5.3.0/include/uapi/linux/bpf.h', needed by 'bpf_helper_defs.h'.  Stop.
  make[3]: *** Waiting for unfinished jobs....
  make[2]: *** [Makefile.perf:757: /tmp/tmp.zq13cHILGB/perf-5.3.0/tools/lib/bpf/libbpf.a] Error 2
  make[2]: *** Waiting for unfinished jobs....

Because $(srcdir) points to the /tmp/tmp.zq13cHILGB/perf-5.3.0 directory
and we need '/tools/ after that variable, and after fixing this then we
get to another problem:

  /bin/sh: /home/acme/git/perf/tools/scripts/bpf_helpers_doc.py: No such file or directory
  make[3]: *** [Makefile:184: bpf_helper_defs.h] Error 127
  make[3]: *** Deleting file 'bpf_helper_defs.h'
    LD       /tmp/build/perf/libapi-in.o
  make[2]: *** [Makefile.perf:778: /tmp/build/perf/libbpf.a] Error 2
  make[2]: *** Waiting for unfinished jobs....

Because this requires something outside the tools/ directories that gets
collected into perf's detached tarballs, to fix it just add it to
tools/perf/MANIFEST, which this patch does, now it works for that case
and also for all these other cases.

Fixes: e01a75c159 ("libbpf: Move bpf_{helpers, helper_defs, endian, tracing}.h into libbpf")
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andrii Nakryiko <andriin@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Martin KaFai Lau <kafai@fb.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Link: https://lkml.kernel.org/n/tip-4pnkg2vmdvq5u6eivc887wen@git.kernel.org
Link: https://lore.kernel.org/bpf/20191126151045.GB19483@kernel.org
2019-11-27 16:52:31 -08:00
Andrii Nakryiko
53f8dd434b libbpf: Fix global variable relocation
Similarly to a0d7da26ce ("libbpf: Fix call relocation offset calculation
bug"), relocations against global variables need to take into account
referenced symbol's st_value, which holds offset into a corresponding data
section (and, subsequently, offset into internal backing map). For static
variables this offset is always zero and data offset is completely described
by respective instruction's imm field.

Convert a bunch of selftests to global variables. Previously they were relying
on `static volatile` trick to ensure Clang doesn't inline static variables,
which with global variables is not necessary anymore.

Fixes: 393cdfbee8 ("libbpf: Support initialized global variables")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191127200651.1381348-1-andriin@fb.com
2019-11-27 16:34:21 -08:00
Andrii Nakryiko
b568405856 libbpf: Fix Makefile' libbpf symbol mismatch diagnostic
Fix Makefile's diagnostic diff output when there is LIBBPF_API-versioned
symbols mismatch.

Fixes: 1bd6352459 ("libbpf: handle symbol versioning properly for libbpf.a")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191127200134.1360660-1-andriin@fb.com
2019-11-27 22:29:02 +01:00
Linus Torvalds
168829ad09 Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
 "The main changes in this cycle were:

   - A comprehensive rewrite of the robust/PI futex code's exit handling
     to fix various exit races. (Thomas Gleixner et al)

   - Rework the generic REFCOUNT_FULL implementation using
     atomic_fetch_* operations so that the performance impact of the
     cmpxchg() loops is mitigated for common refcount operations.

     With these performance improvements the generic implementation of
     refcount_t should be good enough for everybody - and this got
     confirmed by performance testing, so remove ARCH_HAS_REFCOUNT and
     REFCOUNT_FULL entirely, leaving the generic implementation enabled
     unconditionally. (Will Deacon)

   - Other misc changes, fixes, cleanups"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (27 commits)
  lkdtm: Remove references to CONFIG_REFCOUNT_FULL
  locking/refcount: Remove unused 'refcount_error_report()' function
  locking/refcount: Consolidate implementations of refcount_t
  locking/refcount: Consolidate REFCOUNT_{MAX,SATURATED} definitions
  locking/refcount: Move saturation warnings out of line
  locking/refcount: Improve performance of generic REFCOUNT_FULL code
  locking/refcount: Move the bulk of the REFCOUNT_FULL implementation into the <linux/refcount.h> header
  locking/refcount: Remove unused refcount_*_checked() variants
  locking/refcount: Ensure integer operands are treated as signed
  locking/refcount: Define constants for saturation and max refcount values
  futex: Prevent exit livelock
  futex: Provide distinct return value when owner is exiting
  futex: Add mutex around futex exit
  futex: Provide state handling for exec() as well
  futex: Sanitize exit state handling
  futex: Mark the begin of futex exit explicitly
  futex: Set task::futex_state to DEAD right after handling futex exit
  futex: Split futex_mm_release() for exit/exec
  exit/exec: Seperate mm_release()
  futex: Replace PF_EXITPIDONE with a state
  ...
2019-11-26 16:02:40 -08:00
Linus Torvalds
3f59dbcace Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
 "The main kernel side changes in this cycle were:

   - Various Intel-PT updates and optimizations (Alexander Shishkin)

   - Prohibit kprobes on Xen/KVM emulate prefixes (Masami Hiramatsu)

   - Add support for LSM and SELinux checks to control access to the
     perf syscall (Joel Fernandes)

   - Misc other changes, optimizations, fixes and cleanups - see the
     shortlog for details.

  There were numerous tooling changes as well - 254 non-merge commits.
  Here are the main changes - too many to list in detail:

   - Enhancements to core tooling infrastructure, perf.data, libperf,
     libtraceevent, event parsing, vendor events, Intel PT, callchains,
     BPF support and instruction decoding.

   - There were updates to the following tools:

        perf annotate
        perf diff
        perf inject
        perf kvm
        perf list
        perf maps
        perf parse
        perf probe
        perf record
        perf report
        perf script
        perf stat
        perf test
        perf trace

   - And a lot of other changes: please see the shortlog and Git log for
     more details"

* 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (279 commits)
  perf parse: Fix potential memory leak when handling tracepoint errors
  perf probe: Fix spelling mistake "addrees" -> "address"
  libtraceevent: Fix memory leakage in copy_filter_type
  libtraceevent: Fix header installation
  perf intel-bts: Does not support AUX area sampling
  perf intel-pt: Add support for decoding AUX area samples
  perf intel-pt: Add support for recording AUX area samples
  perf pmu: When using default config, record which bits of config were changed by the user
  perf auxtrace: Add support for queuing AUX area samples
  perf session: Add facility to peek at all events
  perf auxtrace: Add support for dumping AUX area samples
  perf inject: Cut AUX area samples
  perf record: Add aux-sample-size config term
  perf record: Add support for AUX area sampling
  perf auxtrace: Add support for AUX area sample recording
  perf auxtrace: Move perf_evsel__find_pmu()
  perf record: Add a function to test for kernel support for AUX area sampling
  perf tools: Add kernel AUX area sampling definitions
  perf/core: Make the mlock accounting simple again
  perf report: Jump to symbol source view from total cycles view
  ...
2019-11-26 15:04:47 -08:00
Linus Torvalds
386403a115 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from David Miller:
 "Another merge window, another pull full of stuff:

   1) Support alternative names for network devices, from Jiri Pirko.

   2) Introduce per-netns netdev notifiers, also from Jiri Pirko.

   3) Support MSG_PEEK in vsock/virtio, from Matias Ezequiel Vara
      Larsen.

   4) Allow compiling out the TLS TOE code, from Jakub Kicinski.

   5) Add several new tracepoints to the kTLS code, also from Jakub.

   6) Support set channels ethtool callback in ena driver, from Sameeh
      Jubran.

   7) New SCTP events SCTP_ADDR_ADDED, SCTP_ADDR_REMOVED,
      SCTP_ADDR_MADE_PRIM, and SCTP_SEND_FAILED_EVENT. From Xin Long.

   8) Add XDP support to mvneta driver, from Lorenzo Bianconi.

   9) Lots of netfilter hw offload fixes, cleanups and enhancements,
      from Pablo Neira Ayuso.

  10) PTP support for aquantia chips, from Egor Pomozov.

  11) Add UDP segmentation offload support to igb, ixgbe, and i40e. From
      Josh Hunt.

  12) Add smart nagle to tipc, from Jon Maloy.

  13) Support L2 field rewrite by TC offloads in bnxt_en, from Venkat
      Duvvuru.

  14) Add a flow mask cache to OVS, from Tonghao Zhang.

  15) Add XDP support to ice driver, from Maciej Fijalkowski.

  16) Add AF_XDP support to ice driver, from Krzysztof Kazimierczak.

  17) Support UDP GSO offload in atlantic driver, from Igor Russkikh.

  18) Support it in stmmac driver too, from Jose Abreu.

  19) Support TIPC encryption and auth, from Tuong Lien.

  20) Introduce BPF trampolines, from Alexei Starovoitov.

  21) Make page_pool API more numa friendly, from Saeed Mahameed.

  22) Introduce route hints to ipv4 and ipv6, from Paolo Abeni.

  23) Add UDP segmentation offload to cxgb4, Rahul Lakkireddy"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1857 commits)
  libbpf: Fix usage of u32 in userspace code
  mm: Implement no-MMU variant of vmalloc_user_node_flags
  slip: Fix use-after-free Read in slip_open
  net: dsa: sja1105: fix sja1105_parse_rgmii_delays()
  macvlan: schedule bc_work even if error
  enetc: add support Credit Based Shaper(CBS) for hardware offload
  net: phy: add helpers phy_(un)lock_mdio_bus
  mdio_bus: don't use managed reset-controller
  ax88179_178a: add ethtool_op_get_ts_info()
  mlxsw: spectrum_router: Fix use of uninitialized adjacency index
  mlxsw: spectrum_router: After underlay moves, demote conflicting tunnels
  bpf: Simplify __bpf_arch_text_poke poke type handling
  bpf: Introduce BPF_TRACE_x helper for the tracing tests
  bpf: Add bpf_jit_blinding_enabled for !CONFIG_BPF_JIT
  bpf, testing: Add various tail call test cases
  bpf, x86: Emit patchable direct jump as tail call
  bpf: Constant map key tracking for prog array pokes
  bpf: Add poke dependency tracking for prog array maps
  bpf: Add initial poke descriptor table for jit images
  bpf: Move owner type, jited info into array auxiliary data
  ...
2019-11-25 20:02:57 -08:00
Linus Torvalds
436b2a8039 Printk changes for 5.5
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Merge tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk

Pull printk updates from Petr Mladek:

 - Allow to print symbolic error names via new %pe modifier.

 - Use pr_warn() instead of the remaining pr_warning() calls. Fix
   formatting of the related lines.

 - Add VSPRINTF entry to MAINTAINERS.

* tag 'printk-for-5.5' of git://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk: (32 commits)
  checkpatch: don't warn about new vsprintf pointer extension '%pe'
  MAINTAINERS: Add VSPRINTF
  tools lib api: Renaming pr_warning to pr_warn
  ASoC: samsung: Use pr_warn instead of pr_warning
  lib: cpu_rmap: Use pr_warn instead of pr_warning
  trace: Use pr_warn instead of pr_warning
  dma-debug: Use pr_warn instead of pr_warning
  vgacon: Use pr_warn instead of pr_warning
  fs: afs: Use pr_warn instead of pr_warning
  sh/intc: Use pr_warn instead of pr_warning
  scsi: Use pr_warn instead of pr_warning
  platform/x86: intel_oaktrail: Use pr_warn instead of pr_warning
  platform/x86: asus-laptop: Use pr_warn instead of pr_warning
  platform/x86: eeepc-laptop: Use pr_warn instead of pr_warning
  oprofile: Use pr_warn instead of pr_warning
  of: Use pr_warn instead of pr_warning
  macintosh: Use pr_warn instead of pr_warning
  idsn: Use pr_warn instead of pr_warning
  ide: Use pr_warn instead of pr_warning
  crypto: n2: Use pr_warn instead of pr_warning
  ...
2019-11-25 19:40:40 -08:00
Andrii Nakryiko
b615e5a1e0 libbpf: Fix usage of u32 in userspace code
u32 is not defined for libbpf when compiled outside of kernel sources (e.g.,
in Github projection). Use __u32 instead.

Fixes: b8c54ea455 ("libbpf: Add support to attach to fentry/fexit tracing progs")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191125212948.1163343-1-andriin@fb.com
2019-11-25 13:52:01 -08:00
Martin KaFai Lau
f9a7cf6eb1 bpf: Introduce BPF_TRACE_x helper for the tracing tests
For BPF_PROG_TYPE_TRACING, the bpf_prog's ctx is an array of u64.
This patch borrows the idea from BPF_CALL_x in filter.h to
convert a u64 to the arg type of the traced function.

The new BPF_TRACE_x has an arg to specify the return type of a bpf_prog.
It will be used in the future TCP-ops bpf_prog that may return "void".

The new macros are defined in the new header file "bpf_trace_helpers.h".
It is under selftests/bpf/ for now.  It could be moved to libbpf later
after seeing more upcoming non-tracing use cases.

The tests are changed to use these new macros also.  Hence,
the k[s]u8/16/32/64 are no longer needed and they are removed
from the bpf_helpers.h.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191123202504.1502696-1-kafai@fb.com
2019-11-24 17:12:11 -08:00
Andrii Nakryiko
1aace10f41 libbpf: Fix bpf_object name determination for bpf_object__open_file()
If bpf_object__open_file() gets path like "some/dir/obj.o", it should derive
BPF object's name as "obj" (unless overriden through opts->object_name).
Instead, due to using `path` as a fallback value for opts->obj_name, path is
used as is for object name, so for above example BPF object's name will be
verbatim "some/dir/obj", which leads to all sorts of troubles, especially when
internal maps are concern (they are using up to 8 characters of object name).
Fix that by ensuring object_name stays NULL, unless overriden.

Fixes: 291ee02b5e ("libbpf: Refactor bpf_object__open APIs to use common opts")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191122003527.551556-1-andriin@fb.com
2019-11-24 16:58:46 -08:00
Andrii Nakryiko
393cdfbee8 libbpf: Support initialized global variables
Initialized global variables are no different in ELF from static variables,
and don't require any extra support from libbpf. But they are matching
semantics of global data (backed by BPF maps) more closely, preventing
LLVM/Clang from aggressively inlining constant values and not requiring
volatile incantations to prevent those. This patch enables global variables.
It still disables uninitialized variables, which will be put into special COM
(common) ELF section, because BPF doesn't allow uninitialized data to be
accessed.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-5-andriin@fb.com
2019-11-24 16:58:45 -08:00
Andrii Nakryiko
8983b731ce libbpf: Fix various errors and warning reported by checkpatch.pl
Fix a bunch of warnings and errors reported by checkpatch.pl, to make it
easier to spot new problems.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-4-andriin@fb.com
2019-11-24 16:58:45 -08:00
Andrii Nakryiko
1f8e2bcb2c libbpf: Refactor relocation handling
Relocation handling code is convoluted and unnecessarily deeply nested. Split
out per-relocation logic into separate function. Also refactor the logic to be
more a sequence of per-relocation type checks and processing steps, making it
simpler to follow control flow. This makes it easier to further extends it to
new kinds of relocations (e.g., support for extern variables).

This patch also makes relocation's section verification more robust.
Previously relocations against not yet supported externs were silently ignored
because of obj->efile.text_shndx was zero, when all BPF programs had custom
section names and there was no .text section. Also, invalid LDIMM64 relocations
against non-map sections were passed through, if they were pointing to a .text
section (or 0, which is invalid section). All these bugs are fixed within this
refactoring and checks are made more appropriate for each type of relocation.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191121070743.1309473-3-andriin@fb.com
2019-11-24 16:58:45 -08:00
Hewenliang
10992af6bf libtraceevent: Fix memory leakage in copy_filter_type
It is necessary to free the memory that we have allocated when error occurs.

Fixes: ef3072cd1d ("tools lib traceevent: Get rid of die in add_filter_type()")
Signed-off-by: Hewenliang <hewenliang4@huawei.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov <tstoyanov@vmware.com>
Link: http://lore.kernel.org/lkml/20191119014415.57210-1-hewenliang4@huawei.com
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-22 10:48:14 -03:00
Sudip Mukherjee
68401a1799 libtraceevent: Fix header installation
When we passed some location in DESTDIR, install_headers called
do_install with DESTDIR as part of the second argument.

But do_install is again using '$(DESTDIR_SQ)$2', so as a result the
headers were installed in a location $DESTDIR/$DESTDIR.

In my testing I passed DESTDIR=/home/sudip/test and the headers were
installed in: /home/sudip/test/home/sudip/test/usr/include/traceevent.

Lets remove DESTDIR from the second argument of do_install so that the
headers are installed in the correct location.

Signed-off-by: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Sudipm Mukherjee <sudipm.mukherjee@gmail.com>
Cc: linux-trace-devel@vger.kernel.org
Link: http://lore.kernel.org/lkml/20191114133719.309-1-sudipm.mukherjee@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-22 10:48:14 -03:00
Andrii Nakryiko
a0d7da26ce libbpf: Fix call relocation offset calculation bug
When relocating subprogram call, libbpf doesn't take into account
relo->text_off, which comes from symbol's value. This generally works fine for
subprograms implemented as static functions, but breaks for global functions.

Taking a simplified test_pkt_access.c as an example:

__attribute__ ((noinline))
static int test_pkt_access_subprog1(volatile struct __sk_buff *skb)
{
        return skb->len * 2;
}

__attribute__ ((noinline))
static int test_pkt_access_subprog2(int val, volatile struct __sk_buff *skb)
{
        return skb->len + val;
}

SEC("classifier/test_pkt_access")
int test_pkt_access(struct __sk_buff *skb)
{
        if (test_pkt_access_subprog1(skb) != skb->len * 2)
                return TC_ACT_SHOT;
        if (test_pkt_access_subprog2(2, skb) != skb->len + 2)
                return TC_ACT_SHOT;
        return TC_ACT_UNSPEC;
}

When compiled, we get two relocations, pointing to '.text' symbol. .text has
st_value set to 0 (it points to the beginning of .text section):

0000000000000008  000000050000000a R_BPF_64_32            0000000000000000 .text
0000000000000040  000000050000000a R_BPF_64_32            0000000000000000 .text

test_pkt_access_subprog1 and test_pkt_access_subprog2 offsets (targets of two
calls) are encoded within call instruction's imm32 part as -1 and 2,
respectively:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       4:       04 00 00 00 02 00 00 00 w0 += 2
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 08 00 00 00 00 00 if w1 != w2 goto +8 <LBB0_3>
       7:       bf 61 00 00 00 00 00 00 r1 = r6
===>   8:       85 10 00 00 02 00 00 00 call 2
       9:       bc 01 00 00 00 00 00 00 w1 = w0
      10:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      11:       04 02 00 00 02 00 00 00 w2 += 2
      12:       b4 00 00 00 ff ff ff ff w0 = -1
      13:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB0_3>
      14:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000078 LBB0_3:
      15:       95 00 00 00 00 00 00 00 exit

Now, if we compile example with global functions, the setup changes.
Relocations are now against specifically test_pkt_access_subprog1 and
test_pkt_access_subprog2 symbols, with test_pkt_access_subprog2 pointing 24
bytes into its respective section (.text), i.e., 3 instructions in:

0000000000000008  000000070000000a R_BPF_64_32            0000000000000000 test_pkt_access_subprog1
0000000000000048  000000080000000a R_BPF_64_32            0000000000000018 test_pkt_access_subprog2

Calls instructions now encode offsets relative to function symbols and are both
set ot -1:

0000000000000000 test_pkt_access_subprog1:
       0:       61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
       1:       64 00 00 00 01 00 00 00 w0 <<= 1
       2:       95 00 00 00 00 00 00 00 exit

0000000000000018 test_pkt_access_subprog2:
       3:       61 20 00 00 00 00 00 00 r0 = *(u32 *)(r2 + 0)
       4:       0c 10 00 00 00 00 00 00 w0 += w1
       5:       95 00 00 00 00 00 00 00 exit

0000000000000000 test_pkt_access:
       0:       bf 16 00 00 00 00 00 00 r6 = r1
===>   1:       85 10 00 00 ff ff ff ff call -1
       2:       bc 01 00 00 00 00 00 00 w1 = w0
       3:       b4 00 00 00 02 00 00 00 w0 = 2
       4:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
       5:       64 02 00 00 01 00 00 00 w2 <<= 1
       6:       5e 21 09 00 00 00 00 00 if w1 != w2 goto +9 <LBB2_3>
       7:       b4 01 00 00 02 00 00 00 w1 = 2
       8:       bf 62 00 00 00 00 00 00 r2 = r6
===>   9:       85 10 00 00 ff ff ff ff call -1
      10:       bc 01 00 00 00 00 00 00 w1 = w0
      11:       61 62 00 00 00 00 00 00 r2 = *(u32 *)(r6 + 0)
      12:       04 02 00 00 02 00 00 00 w2 += 2
      13:       b4 00 00 00 ff ff ff ff w0 = -1
      14:       1e 21 01 00 00 00 00 00 if w1 == w2 goto +1 <LBB2_3>
      15:       b4 00 00 00 02 00 00 00 w0 = 2
0000000000000080 LBB2_3:
      16:       95 00 00 00 00 00 00 00 exit

Thus the right formula to calculate target call offset after relocation should
take into account relocation's target symbol value (offset within section),
call instruction's imm32 offset, and (subtracting, to get relative instruction
offset) instruction index of call instruction itself. All that is shifted by
number of instructions in main program, given all sub-programs are copied over
after main program.

Convert few selftests relying on bpf-to-bpf calls to use global functions
instead of static ones.

Fixes: 48cca7e44f ("libbpf: add support for bpf_call")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191119224447.3781271-1-andriin@fb.com
2019-11-19 15:00:12 -08:00
Luigi Rizzo
3de88c9113 net-af_xdp: Use correct number of channels from ethtool
Drivers use different fields to report the number of channels, so take
the maximum of all data channels (rx, tx, combined) when determining the
size of the xsk map. The current code used only 'combined' which was set
to 0 in some drivers e.g. mlx4.

Tested: compiled and run xdpsock -q 3 -r -S on mlx4

Signed-off-by: Luigi Rizzo <lrizzo@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20191119001951.92930-1-lrizzo@google.com
2019-11-19 14:06:35 -08:00
Konstantin Khlebnikov
10f64581b1 libtraceevent: Fix parsing of event %o and %X argument types
Add missing "%o" and "%X". Ext4 events use "%o" for printing i_mode.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tzvetomir Stoyanov (VMware) <tz.stoyanov@gmail.com>
Link: http://lore.kernel.org/lkml/157338066113.6548.11461421296091086041.stgit@buzz
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-18 13:01:59 -03:00
Andrii Nakryiko
7fe74b4362 libbpf: Make global data internal arrays mmap()-able, if possible
Add detection of BPF_F_MMAPABLE flag support for arrays and add it as an extra
flag to internal global data maps, if supported by kernel. This allows users
to memory-map global data and use it without BPF map operations, greatly
simplifying user experience.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20191117172806.2195367-5-andriin@fb.com
2019-11-18 11:41:59 +01:00
Alexei Starovoitov
e7bf94dbb8 libbpf: Add support for attaching BPF programs to other BPF programs
Extend libbpf api to pass attach_prog_fd into bpf_object__open.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-19-ast@kernel.org
2019-11-15 23:45:37 +01:00
Alexei Starovoitov
11d1e2eeff selftests/bpf: Add test for BPF trampoline
Add sanity test for BPF trampoline that checks kernel functions
with up to 6 arguments of different sizes.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-10-ast@kernel.org
2019-11-15 23:43:15 +01:00
Alexei Starovoitov
b8c54ea455 libbpf: Add support to attach to fentry/fexit tracing progs
Teach libbpf to recognize tracing programs types and attach them to
fentry/fexit.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-7-ast@kernel.org
2019-11-15 23:42:31 +01:00
Alexei Starovoitov
1442e2871b libbpf: Introduce btf__find_by_name_kind()
Introduce btf__find_by_name_kind() helper to search BTF by name and kind, since
name alone can be ambiguous.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191114185720.1641606-6-ast@kernel.org
2019-11-15 23:42:14 +01:00
Magnus Karlsson
a68977d269 libbpf: Allow for creating Rx or Tx only AF_XDP sockets
The libbpf AF_XDP code is extended to allow for the creation of Rx
only or Tx only sockets. Previously it returned an error if the socket
was not initialized for both Rx and Tx.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: William Tu <u9012063@gmail.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1573148860-30254-4-git-send-email-magnus.karlsson@intel.com
2019-11-10 19:30:46 -08:00
Magnus Karlsson
cbf07409d0 libbpf: Support XDP_SHARED_UMEM with external XDP program
Add support in libbpf to create multiple sockets that share a single
umem. Note that an external XDP program need to be supplied that
routes the incoming traffic to the desired sockets. So you need to
supply the libbpf_flag XSK_LIBBPF_FLAGS__INHIBIT_PROG_LOAD and load
your own XDP program.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tested-by: William Tu <u9012063@gmail.com>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1573148860-30254-2-git-send-email-magnus.karlsson@intel.com
2019-11-10 19:30:45 -08:00
Toke Høiland-Jørgensen
1a734efe06 libbpf: Add getter for program size
This adds a new getter for the BPF program size (in bytes). This is useful
for a caller that is trying to predict how much memory will be locked by
loading a BPF object into the kernel.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333185272.88376.10996937115395724683.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen
473f4e133a libbpf: Add bpf_get_link_xdp_info() function to get more XDP information
Currently, libbpf only provides a function to get a single ID for the XDP
program attached to the interface. However, it can be useful to get the
full set of program IDs attached, along with the attachment mode, in one
go. Add a new getter function to support this, using an extendible
structure to carry the information. Express the old bpf_get_link_id()
function in terms of the new function.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157333185164.88376.7520653040667637246.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen
b6e99b010e libbpf: Use pr_warn() when printing netlink errors
The netlink functions were using fprintf(stderr, ) directly to print out
error messages, instead of going through the usual logging macros. This
makes it impossible for the calling application to silence or redirect
those error messages. Fix this by switching to pr_warn() in nlattr.c and
netlink.c.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333185055.88376.15999360127117901443.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen
4f33ddb4e3 libbpf: Propagate EPERM to caller on program load
When loading an eBPF program, libbpf overrides the return code for EPERM
errors instead of returning it to the caller. This makes it hard to figure
out what went wrong on load.

In particular, EPERM is returned when the system rlimit is too low to lock
the memory required for the BPF program. Previously, this was somewhat
obscured because the rlimit error would be hit on map creation (which does
return it correctly). However, since maps can now be reused, object load
can proceed all the way to loading programs without hitting the error;
propagating it even in this case makes it possible for the caller to react
appropriately (and, e.g., attempt to raise the rlimit before retrying).

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333184946.88376.11768171652794234561.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Toke Høiland-Jørgensen
ec6d5f47bf libbpf: Unpin auto-pinned maps if loading fails
Since the automatic map-pinning happens during load, it will leave pinned
maps around if the load fails at a later stage. Fix this by unpinning any
pinned maps on cleanup. To avoid unpinning pinned maps that were reused
rather than newly pinned, add a new boolean property on struct bpf_map to
keep track of whether that map was reused or not; and only unpin those maps
that were not reused.

Fixes: 57a00f4164 ("libbpf: Add auto-pinning of maps when loading BPF objects")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/157333184731.88376.9992935027056165873.stgit@toke.dk
2019-11-10 19:26:30 -08:00
Andrii Nakryiko
98e527af30 libbpf: Improve handling of corrupted ELF during map initialization
If we get ELF file with "maps" section, but no symbols pointing to it, we'll
end up with division by zero. Add check against this situation and exit early
with error. Found by Coverity scan against Github libbpf sources.

Fixes: bf82927125 ("libbpf: refactor map initialization")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-6-andriin@fb.com
2019-11-07 16:20:38 +01:00
Andrii Nakryiko
994021a7e0 libbpf: Make btf__resolve_size logic always check size error condition
Perform size check always in btf__resolve_size. Makes the logic a bit more
robust against corrupted BTF and silences LGTM/Coverity complaining about
always true (size < 0) check.

Fixes: 69eaab04c6 ("btf: extract BTF type size calculation")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-5-andriin@fb.com
2019-11-07 16:20:38 +01:00
Andrii Nakryiko
dd3ab12637 libbpf: Fix another potential overflow issue in bpf_prog_linfo
Fix few issues found by Coverity and LGTM.

Fixes: b053b439b7 ("bpf: libbpf: bpftool: Print bpf_line_info during prog dump")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-4-andriin@fb.com
2019-11-07 16:20:38 +01:00
Andrii Nakryiko
4ee1135615 libbpf: Fix potential overflow issue
Fix a potential overflow issue found by LGTM analysis, based on Github libbpf
source code.

Fixes: 3d65014146 ("bpf: libbpf: Add btf_line_info support to libbpf")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-3-andriin@fb.com
2019-11-07 16:20:37 +01:00
Andrii Nakryiko
3dc5e05982 libbpf: Fix memory leak/double free issue
Coverity scan against Github libbpf code found the issue of not freeing memory and
leaving already freed memory still referenced from bpf_program. Fix it by
re-assigning successfully reallocated memory sooner.

Fixes: 2993e0515b ("tools/bpf: add support to read .BTF.ext sections")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107020855.3834758-2-andriin@fb.com
2019-11-07 16:20:37 +01:00
Andrii Nakryiko
9656b346b2 libbpf: Fix negative FD close() in xsk_setup_xdp_prog()
Fix issue reported by static analysis (Coverity). If bpf_prog_get_fd_by_id()
fails, xsk_lookup_bpf_maps() will fail as well and clean-up code will attempt
close() with fd=-1. Fix by checking bpf_prog_get_fd_by_id() return result and
exiting early.

Fixes: 10a13bb40e ("libbpf: remove qidconf and better support external bpf programs.")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191107054059.313884-1-andriin@fb.com
2019-11-07 16:15:27 +01:00
Andrii Nakryiko
ed57802121 libbpf: Simplify BPF_CORE_READ_BITFIELD_PROBED usage
Streamline BPF_CORE_READ_BITFIELD_PROBED interface to follow
BPF_CORE_READ_BITFIELD (direct) and BPF_CORE_READ, in general, i.e., just
return read result or 0, if underlying bpf_probe_read() failed.

In practice, real applications rarely check bpf_probe_read() result, because
it has to always work or otherwise it's a bug. So propagating internal
bpf_probe_read() error from this macro hurts usability without providing real
benefits in practice. This patch fixes the issue and simplifies usage,
noticeable even in selftest itself.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20191106201500.2582438-1-andriin@fb.com
2019-11-06 13:54:59 -08:00
James Clark
22bd8f1b5a libsubcmd: Use -O0 with DEBUG=1
When a 'make DEBUG=1' build is done, the command parser is still built
with -O6 and is hard to step through, fix it making it use -O0 in that
case.

Signed-off-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: nd <nd@arm.com>
Link: http://lore.kernel.org/lkml/20191028113340.4282-1-james.clark@arm.com
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-06 15:49:39 -03:00
James Clark
d894967fca libsubcmd: Move EXTRA_FLAGS to the end to allow overriding existing flags
Move EXTRA_WARNINGS and EXTRA_FLAGS to the end of the compilation line,
otherwise they cannot be used to override the default values.

Signed-off-by: James Clark <james.clark@arm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: nd <nd@arm.com>
Link: http://lore.kernel.org/lkml/20191028113340.4282-1-james.clark@arm.com
[ split from a larger patch ]
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2019-11-06 15:49:39 -03:00
Andrii Nakryiko
94f060e984 libbpf: Add support for field size relocations
Add bpf_core_field_size() macro, capturing a relocation against field size.
Adjust bits of internal libbpf relocation logic to allow capturing size
relocations of various field types: arrays, structs/unions, enums, etc.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191101222810.1246166-4-andriin@fb.com
2019-11-04 16:06:56 +01:00
Andrii Nakryiko
ee26dade0e libbpf: Add support for relocatable bitfields
Add support for the new field relocation kinds, necessary to support
relocatable bitfield reads. Provide macro for abstracting necessary code doing
full relocatable bitfield extraction into u64 value. Two separate macros are
provided:
- BPF_CORE_READ_BITFIELD macro for direct memory read-enabled BPF programs
(e.g., typed raw tracepoints). It uses direct memory dereference to extract
bitfield backing integer value.
- BPF_CORE_READ_BITFIELD_PROBED macro for cases where bpf_probe_read() needs
to be used to extract same backing integer value.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191101222810.1246166-3-andriin@fb.com
2019-11-04 16:06:56 +01:00
Toke Høiland-Jørgensen
57a00f4164 libbpf: Add auto-pinning of maps when loading BPF objects
This adds support to libbpf for setting map pinning information as part of
the BTF map declaration, to get automatic map pinning (and reuse) on load.
The pinning type currently only supports a single PIN_BY_NAME mode, where
each map will be pinned by its name in a path that can be overridden, but
defaults to /sys/fs/bpf.

Since auto-pinning only does something if any maps actually have a
'pinning' BTF attribute set, we default the new option to enabled, on the
assumption that seamless pinning is what most callers want.

When a map has a pin_path set at load time, libbpf will compare the map
pinned at that location (if any), and if the attributes match, will re-use
that map instead of creating a new one. If no existing map is found, the
newly created map will instead be pinned at the location.

Programs wanting to customise the pinning can override the pinning paths
using bpf_map__set_pin_path() before calling bpf_object__load() (including
setting it to NULL to disable pinning of a particular map).

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269298092.394725.3966306029218559681.stgit@toke.dk
2019-11-02 12:35:07 -07:00
Toke Høiland-Jørgensen
196f8487f5 libbpf: Move directory creation into _pin() functions
The existing pin_*() functions all try to create the parent directory
before pinning. Move this check into the per-object _pin() functions
instead. This ensures consistent behaviour when auto-pinning is
added (which doesn't go through the top-level pin_maps() function), at the
cost of a few more calls to mkdir().

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269297985.394725.5882630952992598610.stgit@toke.dk
2019-11-02 12:35:07 -07:00
Toke Høiland-Jørgensen
4580b25fce libbpf: Store map pin path and status in struct bpf_map
Support storing and setting a pin path in struct bpf_map, which can be used
for automatic pinning. Also store the pin status so we can avoid attempts
to re-pin a map that has already been pinned (or reused from a previous
pinning).

The behaviour of bpf_object__{un,}pin_maps() is changed so that if it is
called with a NULL path argument (which was previously illegal), it will
(un)pin only those maps that have a pin_path set.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269297876.394725.14782206533681896279.stgit@toke.dk
2019-11-02 12:35:07 -07:00
Toke Høiland-Jørgensen
d1b4574a4b libbpf: Fix error handling in bpf_map__reuse_fd()
bpf_map__reuse_fd() was calling close() in the error path before returning
an error value based on errno. However, close can change errno, so that can
lead to potentially misleading error messages. Instead, explicitly store
errno in the err variable before each goto.

Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/157269297769.394725.12634985106772698611.stgit@toke.dk
2019-11-02 12:35:06 -07:00
Alexei Starovoitov
12a8654b2e libbpf: Add support for prog_tracing
Cleanup libbpf from expected_attach_type == attach_btf_id hack
and introduce BPF_PROG_TYPE_TRACING.

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/20191030223212.953010-3-ast@kernel.org
2019-10-31 15:16:59 +01:00
Andrii Nakryiko
a566e35f1e libbpf: Don't use kernel-side u32 type in xsk.c
u32 is a kernel-side typedef. User-space library is supposed to use __u32.
This breaks Github's projection of libbpf. Do u32 -> __u32 fix.

Fixes: 94ff9ebb49 ("libbpf: Fix compatibility for kernels without need_wakeup")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/bpf/20191029055953.2461336-1-andriin@fb.com
2019-10-29 06:38:12 -07:00
Andrii Nakryiko
d3a3aa0c59 libbpf: Fix off-by-one error in ELF sanity check
libbpf's bpf_object__elf_collect() does simple sanity check after iterating
over all ELF sections, if checks that .strtab index is correct. Unfortunately,
due to section indices being 1-based, the check breaks for cases when .strtab
ends up being the very last section in ELF.

Fixes: 77ba9a5b48 ("tools lib bpf: Fetch map names from correct strtab")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191028233727.1286699-1-andriin@fb.com
2019-10-28 20:27:40 -07:00
Magnus Karlsson
94ff9ebb49 libbpf: Fix compatibility for kernels without need_wakeup
When the need_wakeup flag was added to AF_XDP, the format of the
XDP_MMAP_OFFSETS getsockopt was extended. Code was added to the
kernel to take care of compatibility issues arrising from running
applications using any of the two formats. However, libbpf was
not extended to take care of the case when the application/libbpf
uses the new format but the kernel only supports the old
format. This patch adds support in libbpf for parsing the old
format, before the need_wakeup flag was added, and emulating a
set of static need_wakeup flags that will always work for the
application.

v2 -> v3:
* Incorporated code improvements suggested by Jonathan Lemon

v1 -> v2:
* Rebased to bpf-next
* Rewrote the code as the previous version made you blind

Fixes: a4500432c2 ("libbpf: add support for need_wakeup flag in AF_XDP part")
Reported-by: Eloy Degen <degeneloy@gmail.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Link: https://lore.kernel.org/bpf/1571995035-21889-1-git-send-email-magnus.karlsson@intel.com
2019-10-28 20:25:32 -07:00
David S. Miller
5b7fe93db0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:

====================
pull-request: bpf-next 2019-10-27

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

We've added 52 non-merge commits during the last 11 day(s) which contain
a total of 65 files changed, 2604 insertions(+), 1100 deletions(-).

The main changes are:

 1) Revolutionize BPF tracing by using in-kernel BTF to type check BPF
    assembly code. The work here teaches BPF verifier to recognize
    kfree_skb()'s first argument as 'struct sk_buff *' in tracepoints
    such that verifier allows direct use of bpf_skb_event_output() helper
    used in tc BPF et al (w/o probing memory access) that dumps skb data
    into perf ring buffer. Also add direct loads to probe memory in order
    to speed up/replace bpf_probe_read() calls, from Alexei Starovoitov.

 2) Big batch of changes to improve libbpf and BPF kselftests. Besides
    others: generalization of libbpf's CO-RE relocation support to now
    also include field existence relocations, revamp the BPF kselftest
    Makefile to add test runner concept allowing to exercise various
    ways to build BPF programs, and teach bpf_object__open() and friends
    to automatically derive BPF program type/expected attach type from
    section names to ease their use, from Andrii Nakryiko.

 3) Fix deadlock in stackmap's build-id lookup on rq_lock(), from Song Liu.

 4) Allow to read BTF as raw data from bpftool. Most notable use case
    is to dump /sys/kernel/btf/vmlinux through this, from Jiri Olsa.

 5) Use bpf_redirect_map() helper in libbpf's AF_XDP helper prog which
    manages to improve "rx_drop" performance by ~4%., from Björn Töpel.

 6) Fix to restore the flow dissector after reattach BPF test and also
    fix error handling in bpf_helper_defs.h generation, from Jakub Sitnicki.

 7) Improve verifier's BTF ctx access for use outside of raw_tp, from
    Martin KaFai Lau.

 8) Improve documentation for AF_XDP with new sections and to reflect
    latest features, from Magnus Karlsson.

 9) Add back 'version' section parsing to libbpf for old kernels, from
    John Fastabend.

10) Fix strncat bounds error in libbpf's libbpf_prog_type_by_name(),
    from KP Singh.

11) Turn on -mattr=+alu32 in LLVM by default for BPF kselftests in order
    to improve insn coverage for built BPF progs, from Yonghong Song.

12) Misc minor cleanups and fixes, from various others.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-26 22:57:27 -07:00
KP Singh
58eeb2289a libbpf: Fix strncat bounds error in libbpf_prog_type_by_name
On compiling samples with this change, one gets an error:

 error: ‘strncat’ specified bound 118 equals destination size
  [-Werror=stringop-truncation]

    strncat(dst, name + section_names[i].len,
    ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
     sizeof(raw_tp_btf_name) - (dst - raw_tp_btf_name));
     ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

strncat requires the destination to have enough space for the
terminating null byte.

Fixes: f75a697e09 ("libbpf: Auto-detect btf_id of BTF-based raw_tracepoint")
Signed-off-by: KP Singh <kpsingh@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20191023154038.24075-1-kpsingh@chromium.org
2019-10-23 10:17:28 -07:00
Björn Töpel
d7d962a095 libbpf: Use implicit XSKMAP lookup from AF_XDP XDP program
In commit 43e74c0267 ("bpf_xdp_redirect_map: Perform map lookup in
eBPF helper") the bpf_redirect_map() helper learned to do map lookup,
which means that the explicit lookup in the XDP program for AF_XDP is
not needed for post-5.3 kernels.

This commit adds the implicit map lookup with default action, which
improves the performance for the "rx_drop" [1] scenario with ~4%.

For pre-5.3 kernels, the bpf_redirect_map() returns XDP_ABORTED, and a
fallback path for backward compatibility is entered, where explicit
lookup is still performed. This means a slight regression for older
kernels (an additional bpf_redirect_map() call), but I consider that a
fair punishment for users not upgrading their kernels. ;-)

v1->v2: Backward compatibility (Toke) [2]
v2->v3: Avoid masking/zero-extension by using JMP32 [3]

[1] # xdpsock -i eth0 -z -r
[2] https://lore.kernel.org/bpf/87pnirb3dc.fsf@toke.dk/
[3] https://lore.kernel.org/bpf/87v9sip0i8.fsf@toke.dk/

Suggested-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191022072206.6318-1-bjorn.topel@gmail.com
2019-10-23 10:03:52 -07:00
Andrii Nakryiko
e00aca65e6 libbpf: Make DECLARE_LIBBPF_OPTS macro strictly a variable declaration
LIBBPF_OPTS is implemented as a mix of field declaration and memset
+ assignment. This makes it neither variable declaration nor purely
statements, which is a problem, because you can't mix it with either
other variable declarations nor other function statements, because C90
compiler mode emits warning on mixing all that together.

This patch changes LIBBPF_OPTS into a strictly declaration of variable
and solves this problem, as can be seen in case of bpftool, which
previously would emit compiler warning, if done this way (LIBBPF_OPTS as
part of function variables declaration block).

This patch also renames LIBBPF_OPTS into DECLARE_LIBBPF_OPTS to follow
kernel convention for similar macros more closely.

v1->v2:
- rename LIBBPF_OPTS into DECLARE_LIBBPF_OPTS (Jakub Sitnicki).

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20191022172100.3281465-1-andriin@fb.com
2019-10-22 21:35:03 +02:00
Andrii Nakryiko
dd4436bb83 libbpf: Teach bpf_object__open to guess program types
Teach bpf_object__open how to guess program type and expected attach
type from section names, similar to what bpf_prog_load() does. This
seems like a really useful features and an oversight to not have this
done during bpf_object_open(). To preserver backwards compatible
behavior of bpf_prog_load(), its attr->prog_type is treated as an
override of bpf_object__open() decisions, if attr->prog_type is not
UNSPECIFIED.

There is a slight difference in behavior for bpf_prog_load().
Previously, if bpf_prog_load() was loading BPF object with more than one
program, first program's guessed program type and expected attach type
would determine corresponding attributes of all the subsequent program
types, even if their sections names suggest otherwise. That seems like
a rather dubious behavior and with this change it will behave more
sanely: each program's type is determined individually, unless they are
forced to uniformity through attr->prog_type.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191021033902.3856966-5-andriin@fb.com
2019-10-21 14:49:12 +02:00
Andrii Nakryiko
32dff6db29 libbpf: Add uprobe/uretprobe and tp/raw_tp section suffixes
Map uprobe/uretprobe into KPROBE program type. tp/raw_tp are just an
alias for more verbose tracepoint/raw_tracepoint, respectively.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191021033902.3856966-4-andriin@fb.com
2019-10-21 14:49:12 +02:00
Andrii Nakryiko
f1eead9e3c libbpf: Add bpf_program__get_{type, expected_attach_type) APIs
There are bpf_program__set_type() and
bpf_program__set_expected_attach_type(), but no corresponding getters,
which seems rather incomplete. Fix this.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20191021033902.3856966-3-andriin@fb.com
2019-10-21 14:49:12 +02:00
Kefeng Wang
be18010ea2 tools, bpf: Rename pr_warning to pr_warn to align with kernel logging
For kernel logging macros, pr_warning() is completely removed and
replaced by pr_warn(). By using pr_warn() in tools/lib/bpf/ for
symmetry to kernel logging macros, we could eventually drop the
use of pr_warning() in the whole kernel tree.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20191021055532.185245-1-wangkefeng.wang@huawei.com
2019-10-21 14:38:41 +02:00
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
David S. Miller
2f184393e0 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Several cases of overlapping changes which were for the most
part trivially resolvable.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-20 10:43:00 -07:00
Linus Torvalds
531e93d114 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from David Miller:
 "I was battling a cold after some recent trips, so quite a bit piled up
  meanwhile, sorry about that.

  Highlights:

   1) Fix fd leak in various bpf selftests, from Brian Vazquez.

   2) Fix crash in xsk when device doesn't support some methods, from
      Magnus Karlsson.

   3) Fix various leaks and use-after-free in rxrpc, from David Howells.

   4) Fix several SKB leaks due to confusion of who owns an SKB and who
      should release it in the llc code. From Eric Biggers.

   5) Kill a bunc of KCSAN warnings in TCP, from Eric Dumazet.

   6) Jumbo packets don't work after resume on r8169, as the BIOS resets
      the chip into non-jumbo mode during suspend. From Heiner Kallweit.

   7) Corrupt L2 header during MPLS push, from Davide Caratti.

   8) Prevent possible infinite loop in tc_ctl_action, from Eric
      Dumazet.

   9) Get register bits right in bcmgenet driver, based upon chip
      version. From Florian Fainelli.

  10) Fix mutex problems in microchip DSA driver, from Marek Vasut.

  11) Cure race between route lookup and invalidation in ipv4, from Wei
      Wang.

  12) Fix performance regression due to false sharing in 'net'
      structure, from Eric Dumazet"

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (145 commits)
  net: reorder 'struct net' fields to avoid false sharing
  net: dsa: fix switch tree list
  net: ethernet: dwmac-sun8i: show message only when switching to promisc
  net: aquantia: add an error handling in aq_nic_set_multicast_list
  net: netem: correct the parent's backlog when corrupted packet was dropped
  net: netem: fix error path for corrupted GSO frames
  macb: propagate errors when getting optional clocks
  xen/netback: fix error path of xenvif_connect_data()
  net: hns3: fix mis-counting IRQ vector numbers issue
  net: usb: lan78xx: Connect PHY before registering MAC
  vsock/virtio: discard packets if credit is not respected
  vsock/virtio: send a credit update when buffer size is changed
  mlxsw: spectrum_trap: Push Ethernet header before reporting trap
  net: ensure correct skb->tstamp in various fragmenters
  net: bcmgenet: reset 40nm EPHY on energy detect
  net: bcmgenet: soft reset 40nm EPHYs before MAC init
  net: phy: bcm7xxx: define soft_reset for 40nm EPHY
  net: bcmgenet: don't set phydev->link from MAC
  net: Update address for MediaTek ethernet driver in MAINTAINERS
  ipv4: fix race condition between route lookup and invalidation
  ...
2019-10-19 17:09:11 -04:00
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
Kefeng Wang
c405c37bd9 tools lib api: Renaming pr_warning to pr_warn
For kernel logging macro, pr_warning is completely removed and
replaced by pr_warn, using pr_warn in tools lib api for symmetry
to kernel logging macro, then we could drop pr_warning in the
whole linux code.

Changing __pr_warning to __pr_warn to be consistent.

Link: http://lkml.kernel.org/r/20191018031850.48498-30-wangkefeng.wang@huawei.com
To: linux-kernel@vger.kernel.org
Cc: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
2019-10-18 15:02:57 +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