Commit Graph

38 Commits

Author SHA1 Message Date
Daniel Borkmann
1d382264d9 bpf, libbpf: fix version info and add it to shared object
Even though libbpf's versioning script for the linker (libbpf.map)
is pointing to 0.0.2, the BPF_EXTRAVERSION in the Makefile has
not been updated along with it and is therefore still on 0.0.1.

While fixing up, I also noticed that the generated shared object
versioning information is missing, typical convention is to have
a linker name (libbpf.so), soname (libbpf.so.0) and real name
(libbpf.so.0.0.2) for library management. This is based upon the
LIBBPF_VERSION as well.

The build will then produce the following bpf libraries:

  # ll libbpf*
  libbpf.a
  libbpf.so -> libbpf.so.0.0.2
  libbpf.so.0 -> libbpf.so.0.0.2
  libbpf.so.0.0.2

  # readelf -d libbpf.so.0.0.2 | grep SONAME
  0x000000000000000e (SONAME)             Library soname: [libbpf.so.0]

And install them accordingly:

  # rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld install

  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...                           bpf: [ on  ]

    CC       /tmp/bld/libbpf.o
    CC       /tmp/bld/bpf.o
    CC       /tmp/bld/nlattr.o
    CC       /tmp/bld/btf.o
    CC       /tmp/bld/libbpf_errno.o
    CC       /tmp/bld/str_error.o
    CC       /tmp/bld/netlink.o
    CC       /tmp/bld/bpf_prog_linfo.o
    CC       /tmp/bld/libbpf_probes.o
    CC       /tmp/bld/xsk.o
    LD       /tmp/bld/libbpf-in.o
    LINK     /tmp/bld/libbpf.a
    LINK     /tmp/bld/libbpf.so.0.0.2
    LINK     /tmp/bld/test_libbpf
    INSTALL  /tmp/bld/libbpf.a
    INSTALL  /tmp/bld/libbpf.so.0.0.2

  # ll /usr/local/lib64/libbpf.*
  /usr/local/lib64/libbpf.a
  /usr/local/lib64/libbpf.so -> libbpf.so.0.0.2
  /usr/local/lib64/libbpf.so.0 -> libbpf.so.0.0.2
  /usr/local/lib64/libbpf.so.0.0.2

Fixes: 1bf4b05810 ("tools: bpftool: add probes for eBPF program types")
Fixes: 1b76c13e4b ("bpf tools: Introduce 'bpf' library and add bpf feature check")
Reported-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-03-24 19:49:04 -07:00
Stanislav Fomichev
8e2688876c libbpf: force fixdep compilation at the start of the build
libbpf targets don't explicitly depend on fixdep target, so when
we do 'make -j$(nproc)', there is a high probability, that some
objects will be built before fixdep binary is available.

Fix this by running sub-make; this makes sure that fixdep dependency
is properly accounted for.

For the same issue in perf, see commit abb26210a3 ("perf tools: Force
fixdep compilation at the start of the build").

Before:

$ rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld -C tools/lib/bpf/

Auto-detecting system features:
...                        libelf: [ on  ]
...                           bpf: [ on  ]

  HOSTCC   /tmp/bld/fixdep.o
  CC       /tmp/bld/libbpf.o
  CC       /tmp/bld/bpf.o
  CC       /tmp/bld/btf.o
  CC       /tmp/bld/nlattr.o
  CC       /tmp/bld/libbpf_errno.o
  CC       /tmp/bld/str_error.o
  CC       /tmp/bld/netlink.o
  CC       /tmp/bld/bpf_prog_linfo.o
  CC       /tmp/bld/libbpf_probes.o
  CC       /tmp/bld/xsk.o
  HOSTLD   /tmp/bld/fixdep-in.o
  LINK     /tmp/bld/fixdep
  LD       /tmp/bld/libbpf-in.o
  LINK     /tmp/bld/libbpf.a
  LINK     /tmp/bld/libbpf.so
  LINK     /tmp/bld/test_libbpf

$ head /tmp/bld/.libbpf.o.cmd
 # cannot find fixdep (/usr/local/google/home/sdf/src/linux/xxx//fixdep)
 # using basic dep data

/tmp/bld/libbpf.o: libbpf.c /usr/include/stdc-predef.h \
 /usr/include/stdlib.h /usr/include/features.h \
 /usr/include/x86_64-linux-gnu/sys/cdefs.h \
 /usr/include/x86_64-linux-gnu/bits/wordsize.h \
 /usr/include/x86_64-linux-gnu/gnu/stubs.h \
 /usr/include/x86_64-linux-gnu/gnu/stubs-64.h \
 /usr/lib/gcc/x86_64-linux-gnu/7/include/stddef.h \

After:

$ rm -rf /tmp/bld; mkdir /tmp/bld; make -j$(nproc) O=/tmp/bld -C tools/lib/bpf/

Auto-detecting system features:
...                        libelf: [ on  ]
...                           bpf: [ on  ]

  HOSTCC   /tmp/bld/fixdep.o
  HOSTLD   /tmp/bld/fixdep-in.o
  LINK     /tmp/bld/fixdep
  CC       /tmp/bld/libbpf.o
  CC       /tmp/bld/bpf.o
  CC       /tmp/bld/nlattr.o
  CC       /tmp/bld/btf.o
  CC       /tmp/bld/libbpf_errno.o
  CC       /tmp/bld/str_error.o
  CC       /tmp/bld/netlink.o
  CC       /tmp/bld/bpf_prog_linfo.o
  CC       /tmp/bld/libbpf_probes.o
  CC       /tmp/bld/xsk.o
  LD       /tmp/bld/libbpf-in.o
  LINK     /tmp/bld/libbpf.a
  LINK     /tmp/bld/libbpf.so
  LINK     /tmp/bld/test_libbpf

$ head /tmp/bld/.libbpf.o.cmd
cmd_/tmp/bld/libbpf.o := gcc -Wp,-MD,/tmp/bld/.libbpf.o.d -Wp,-MT,/tmp/bld/libbpf.o -g -Wall -DHAVE_LIBELF_MMAP_SUPPORT -DCOMPAT_NEED_REALLOCARRAY -Wbad-function-cast -Wdeclaration-after-statement -Wformat-security -Wformat-y2k -Winit-self -Wmissing-declarations -Wmissing-prototypes -Wnested-externs -Wno-system-headers -Wold-style-definition -Wpacked -Wredundant-decls -Wshadow -Wstrict-prototypes -Wswitch-default -Wswitch-enum -Wundef -Wwrite-strings -Wformat -Wstrict-aliasing=3 -Werror -Wall -fPIC -I. -I/usr/local/google/home/sdf/src/linux/tools/include -I/usr/local/google/home/sdf/src/linux/tools/arch/x86/include/uapi -I/usr/local/google/home/sdf/src/linux/tools/include/uapi -fvisibility=hidden -D"BUILD_STR(s)=$(pound)s" -c -o /tmp/bld/libbpf.o libbpf.c

source_/tmp/bld/libbpf.o := libbpf.c

deps_/tmp/bld/libbpf.o := \
  /usr/include/stdc-predef.h \
  /usr/include/stdlib.h \
  /usr/include/features.h \
  /usr/include/x86_64-linux-gnu/sys/cdefs.h \
  /usr/include/x86_64-linux-gnu/bits/wordsize.h \

Fixes: 7c422f5572 ("tools build: Build fixdep helper from perf and basic libs")
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-07 10:44:41 +01:00
Jakub Kicinski
771744f9dc tools: libbpf: make sure readelf shows full names in build checks
readelf truncates its output by default to attempt to make it more
readable.  This can lead to function names getting aliased if they
differ late in the string.  Use --wide parameter to avoid
truncation.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-03-01 00:53:46 +01:00
Magnus Karlsson
1cad078842 libbpf: add support for using AF_XDP sockets
This commit adds AF_XDP support to libbpf. The main reason for this is
to facilitate writing applications that use AF_XDP by offering
higher-level APIs that hide many of the details of the AF_XDP
uapi. This is in the same vein as libbpf facilitates XDP adoption by
offering easy-to-use higher level interfaces of XDP
functionality. Hopefully this will facilitate adoption of AF_XDP, make
applications using it simpler and smaller, and finally also make it
possible for applications to benefit from optimizations in the AF_XDP
user space access code. Previously, people just copied and pasted the
code from the sample application into their application, which is not
desirable.

The interface is composed of two parts:

* Low-level access interface to the four rings and the packet
* High-level control plane interface for creating and setting
  up umems and af_xdp sockets as well as a simple XDP program.

Tested-by: Björn Töpel <bjorn.topel@intel.com>
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-02-25 23:21:42 +01:00
Stanislav Fomichev
eeedd3527d libbpf: don't define CC and AR
We are already including tools/scripts/Makefile.include which correctly
handles CROSS_COMPILE, no need to define our own vars.

See related commit 7ed1c1901f ("tools: fix cross-compile var clobbering")
for more details.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-01-16 22:47:43 +01:00
Andrey Ignatov
306b267cb3 libbpf: Verify versioned symbols
Since ABI versioning info is kept separately from the code it's easy to
forget to update it while adding a new API.

Add simple verification that all global symbols exported with LIBBPF_API
are versioned in libbpf.map version script.

The idea is to check that number of global symbols in libbpf-in.o, that
is the input to the linker, matches with number of unique versioned
symbols in libbpf.so, that is the output of the linker. If these numbers
don't match, it may mean some symbol was not versioned and make will
fail.

"Unique" means that if a symbol is present in more than one version of
ABI due to ABI changes, it'll be counted once.

Another option to calculate number of global symbols in the "input"
could be to count number of LIBBPF_ABI entries in C headers but it seems
to be fragile.

Example of output when a symbol is missing in version script:

    ...
    LD       libbpf-in.o
    LINK     libbpf.a
    LINK     libbpf.so
  Warning: Num of global symbols in libbpf-in.o (115) does NOT match
  with num of versioned symbols in libbpf.so (114). Please make sure all
  LIBBPF_API symbols are versioned in libbpf.map.
  make: *** [check_abi] Error 1

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-26 18:57:14 -08:00
Andrey Ignatov
16192a771d libbpf: Add version script for DSO
More and more projects use libbpf and one day it'll likely be packaged
and distributed as DSO and that requires ABI versioning so that both
compatible and incompatible changes to ABI can be introduced in a safe
way in the future without breaking executables dynamically linked with a
previous version of the library.

Usual way to do ABI versioning is version script for the linker. Add
such a script for libbpf. All global symbols currently exported via
LIBBPF_API macro are added to the version script libbpf.map.

The version name LIBBPF_0.0.1 is constructed from the name of the
library + version specified by $(LIBBPF_VERSION) in Makefile.

Version script does not duplicate the work done by LIBBPF_API macro, it
rather complements it. The macro is used at compile time and can be used
by compiler to do optimization that can't be done at link time, it is
purely about global symbol visibility. The version script, in turn, is
used at link time and takes care of ABI versioning. Both techniques are
described in details in [1].

Whenever ABI is changed in the future, version script should be changed
appropriately.

[1] https://www.akkadia.org/drepper/dsohowto.pdf

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-11-26 18:57:14 -08:00
Stanislav Fomichev
8c4905b995 libbpf: make sure bpf headers are c++ include-able
Wrap headers in extern "C", to turn off C++ mangling.
This simplifies including libbpf in c++ and linking against it.

v2 changes:
* do the same for btf.h

v3 changes:
* test_libbpf.cpp to test for possible future c++ breakages

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-11-21 23:15:41 +01:00
Andrey Ignatov
ab9e084821 libbpf: Per-symbol visibility for DSO
Make global symbols in libbpf DSO hidden by default with
-fvisibility=hidden and export symbols that are part of ABI explicitly
with __attribute__((visibility("default"))).

This is common practice that should prevent from accidentally exporting
a symbol, that is not supposed to be a part of ABI what, in turn,
improves both libbpf developer- and user-experiences. See [1] for more
details.

Export control becomes more important since more and more projects use
libbpf.

The patch doesn't export a bunch of netlink related functions since as
agreed in [2] they'll be reworked. That doesn't break bpftool since
bpftool links libbpf statically.

[1] https://www.akkadia.org/drepper/dsohowto.pdf (2.2 Export Control)
[2] https://www.mail-archive.com/netdev@vger.kernel.org/msg251434.html

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-16 15:16:47 -07:00
Yonghong Song
438363c0fe tools/bpf: use proper type and uapi perf_event.h header for libbpf
Use __u32 instead u32 in libbpf.c and also use
uapi perf_event.h instead of tools/perf/perf-sys.h.

Signed-off-by: Yonghong Song <yhs@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-10-09 22:03:28 -07:00
Alexei Starovoitov
1bc38b8ff6 libbpf: relicense libbpf as LGPL-2.1 OR BSD-2-Clause
libbpf is maturing as a library and gaining features that no other bpf libraries support
(BPF Type Format, bpf to bpf calls, etc)
Many Apache2 licensed projects (like bcc, bpftrace, gobpf, cilium, etc)
would like to use libbpf, but cannot do this yet, since Apache Foundation explicitly
states that LGPL is incompatible with Apache2.
Hence let's relicense libbpf as dual license LGPL-2.1 or BSD-2-Clause,
since BSD-2 is compatible with Apache2.
Dual LGPL or Apache2 is invalid combination.
Fix license mistake in Makefile as well.

Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Acked-by: Björn Töpel <bjorn.topel@intel.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Beckett <david.beckett@netronome.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Joe Stringer <joe@ovn.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Thomas Graf <tgraf@suug.ch>
Acked-by: Roman Gushchin <guro@fb.com>
Acked-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-10-08 10:09:48 +02:00
Jakub Kicinski
b4b5bffd6c tools: libbpf: remove libelf-getphdrnum feature detection
libbpf does not depend on libelf-getphdrnum feature, don't check it.

$ git grep HAVE_ELF_GETPHDRNUM_SUPPORT
tools/perf/Makefile.config:    CFLAGS += -DHAVE_ELF_GETPHDRNUM_SUPPORT
tools/perf/util/symbol-elf.c:#ifndef HAVE_ELF_GETPHDRNUM_SUPPORT

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-07-16 16:36:49 -07:00
Jakub Kicinski
531b014e7a tools: bpf: make use of reallocarray
reallocarray() is a safer variant of realloc which checks for
multiplication overflow in case of array allocation.  Since it's
not available in Glibc < 2.26 import kernel's overflow.h and
add a static inline implementation when needed.  Use feature
detection to probe for existence of reallocarray.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Reviewed-by: Jiong Wang <jiong.wang@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-07-11 22:13:34 +02:00
Andrey Ignatov
a493f5f9d8 libbpf: Install btf.h with libbpf
install_headers target should contain all headers that are part of
libbpf. Add missing btf.h

Signed-off-by: Andrey Ignatov <rdna@fb.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Acked-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-28 00:25:32 +02:00
Jakub Kicinski
d0cabbb021 tools: bpf: move the event reading loop to libbpf
There are two copies of event reading loop - in bpftool and
trace_helpers "library".  Consolidate them and move the code
to libbpf.  Return codes from trace_helpers are kept, but
renamed to include LIBBPF prefix.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-05-11 01:40:52 +02:00
Eric Leblond
dc2b9f19e3 tools: add netlink.h and if_link.h in tools uapi
The headers are necessary for libbpf compilation on system with older
version of the headers.

Signed-off-by: Eric Leblond <eric@regit.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2018-02-02 17:53:47 -08:00
Jesper Dangaard Brouer
7110d80d53 libbpf: Makefile set specified permission mode
The third parameter to do_install was not used by $(INSTALL) command.
Fix this by only setting the -m option when the third parameter is supplied.

The use of a third parameter was introduced in commit  eb54e522a0 ("bpf:
install libbpf headers on 'make install'").

Without this change, the header files are install as executables files (755).

Fixes: eb54e522a0 ("bpf: install libbpf headers on 'make install'")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-17 01:18:10 +01:00
Jesper Dangaard Brouer
63c859101e libbpf: cleanup Makefile, remove unused elements
The plugin_dir_SQ variable is not used, remove it.
The function update_dir is also unused, remove it.
The variable $VERSION_FILES is empty, remove it.

These all originates from the introduction of the Makefile, and is likely a copy paste
from tools/lib/traceevent/Makefile.

Fixes: 1b76c13e4b ("bpf tools: Introduce 'bpf' library and add bpf feature check")
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-17 01:18:10 +01:00
Jesper Dangaard Brouer
7d386c6249 libbpf: install the header file libbpf.h
It seems like an oversight not to install the header file for libbpf,
given the libbpf.so + libbpf.a files are installed.

Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2018-01-17 01:18:10 +01:00
Jakub Kicinski
21567eded9 libbpf: fix Makefile exit code if libelf not found
/bin/sh's exit does not recognize -1 as a number, leading to
the following error message:

/bin/sh: 1: exit: Illegal number: -1

Use 1 as the exit code.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2017-12-17 20:40:29 +01:00
Greg Kroah-Hartman
b24413180f License cleanup: add SPDX GPL-2.0 license identifier to files with no license
Many source files in the tree are missing licensing information, which
makes it harder for compliance tools to determine the correct license.

By default all files without license information are under the default
license of the kernel, which is GPL version 2.

Update the files which contain no license information with the 'GPL-2.0'
SPDX license identifier.  The SPDX identifier is a legally binding
shorthand, which can be used instead of the full boiler plate text.

This patch is based on work done by Thomas Gleixner and Kate Stewart and
Philippe Ombredanne.

How this work was done:

Patches were generated and checked against linux-4.14-rc6 for a subset of
the use cases:
 - file had no licensing information it it.
 - file was a */uapi/* one with no licensing information in it,
 - file was a */uapi/* one with existing licensing information,

Further patches will be generated in subsequent months to fix up cases
where non-standard license headers were used, and references to license
had to be inferred by heuristics based on keywords.

The analysis to determine which SPDX License Identifier to be applied to
a file was done in a spreadsheet of side by side results from of the
output of two independent scanners (ScanCode & Windriver) producing SPDX
tag:value files created by Philippe Ombredanne.  Philippe prepared the
base worksheet, and did an initial spot review of a few 1000 files.

The 4.13 kernel was the starting point of the analysis with 60,537 files
assessed.  Kate Stewart did a file by file comparison of the scanner
results in the spreadsheet to determine which SPDX license identifier(s)
to be applied to the file. She confirmed any determination that was not
immediately clear with lawyers working with the Linux Foundation.

Criteria used to select files for SPDX license identifier tagging was:
 - Files considered eligible had to be source code files.
 - Make and config files were included as candidates if they contained >5
   lines of source
 - File already had some variant of a license header in it (even if <5
   lines).

All documentation files were explicitly excluded.

The following heuristics were used to determine which SPDX license
identifiers to apply.

 - when both scanners couldn't find any license traces, file was
   considered to have no license information in it, and the top level
   COPYING file license applied.

   For non */uapi/* files that summary was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0                                              11139

   and resulted in the first patch in this series.

   If that file was a */uapi/* path one, it was "GPL-2.0 WITH
   Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:

   SPDX license identifier                            # files
   ---------------------------------------------------|-------
   GPL-2.0 WITH Linux-syscall-note                        930

   and resulted in the second patch in this series.

 - if a file had some form of licensing information in it, and was one
   of the */uapi/* ones, it was denoted with the Linux-syscall-note if
   any GPL family license was found in the file or had no licensing in
   it (per prior point).  Results summary:

   SPDX license identifier                            # files
   ---------------------------------------------------|------
   GPL-2.0 WITH Linux-syscall-note                       270
   GPL-2.0+ WITH Linux-syscall-note                      169
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
   ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
   LGPL-2.1+ WITH Linux-syscall-note                      15
   GPL-1.0+ WITH Linux-syscall-note                       14
   ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
   LGPL-2.0+ WITH Linux-syscall-note                       4
   LGPL-2.1 WITH Linux-syscall-note                        3
   ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
   ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1

   and that resulted in the third patch in this series.

 - when the two scanners agreed on the detected license(s), that became
   the concluded license(s).

 - when there was disagreement between the two scanners (one detected a
   license but the other didn't, or they both detected different
   licenses) a manual inspection of the file occurred.

 - In most cases a manual inspection of the information in the file
   resulted in a clear resolution of the license that should apply (and
   which scanner probably needed to revisit its heuristics).

 - When it was not immediately clear, the license identifier was
   confirmed with lawyers working with the Linux Foundation.

 - If there was any question as to the appropriate license identifier,
   the file was flagged for further research and to be revisited later
   in time.

In total, over 70 hours of logged manual review was done on the
spreadsheet to determine the SPDX license identifiers to apply to the
source files by Kate, Philippe, Thomas and, in some cases, confirmation
by lawyers working with the Linux Foundation.

Kate also obtained a third independent scan of the 4.13 code base from
FOSSology, and compared selected files where the other two scanners
disagreed against that SPDX file, to see if there was new insights.  The
Windriver scanner is based on an older version of FOSSology in part, so
they are related.

Thomas did random spot checks in about 500 files from the spreadsheets
for the uapi headers and agreed with SPDX license identifier in the
files he inspected. For the non-uapi files Thomas did random spot checks
in about 15000 files.

In initial set of patches against 4.14-rc6, 3 files were found to have
copy/paste license identifier errors, and have been fixed to reflect the
correct identifier.

Additionally Philippe spent 10 hours this week doing a detailed manual
inspection and review of the 12,461 patched files from the initial patch
version early this week with:
 - a full scancode scan run, collecting the matched texts, detected
   license ids and scores
 - reviewing anything where there was a license detected (about 500+
   files) to ensure that the applied SPDX license was correct
 - reviewing anything where there was no detection but the patch license
   was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
   SPDX license was correct

This produced a worksheet with 20 files needing minor correction.  This
worksheet was then exported into 3 different .csv files for the
different types of files to be modified.

These .csv files were then reviewed by Greg.  Thomas wrote a script to
parse the csv files and add the proper SPDX tag to the file, in the
format that the file expected.  This script was further refined by Greg
based on the output to detect more types of files automatically and to
distinguish between header and source .c files (which need different
comment types.)  Finally Greg ran the script using the .csv files to
generate the patches.

Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-02 11:10:55 +01:00
Linus Torvalds
aae3dbb477 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next
Pull networking updates from David Miller:

 1) Support ipv6 checksum offload in sunvnet driver, from Shannon
    Nelson.

 2) Move to RB-tree instead of custom AVL code in inetpeer, from Eric
    Dumazet.

 3) Allow generic XDP to work on virtual devices, from John Fastabend.

 4) Add bpf device maps and XDP_REDIRECT, which can be used to build
    arbitrary switching frameworks using XDP. From John Fastabend.

 5) Remove UFO offloads from the tree, gave us little other than bugs.

 6) Remove the IPSEC flow cache, from Florian Westphal.

 7) Support ipv6 route offload in mlxsw driver.

 8) Support VF representors in bnxt_en, from Sathya Perla.

 9) Add support for forward error correction modes to ethtool, from
    Vidya Sagar Ravipati.

10) Add time filter for packet scheduler action dumping, from Jamal Hadi
    Salim.

11) Extend the zerocopy sendmsg() used by virtio and tap to regular
    sockets via MSG_ZEROCOPY. From Willem de Bruijn.

12) Significantly rework value tracking in the BPF verifier, from Edward
    Cree.

13) Add new jump instructions to eBPF, from Daniel Borkmann.

14) Rework rtnetlink plumbing so that operations can be run without
    taking the RTNL semaphore. From Florian Westphal.

15) Support XDP in tap driver, from Jason Wang.

16) Add 32-bit eBPF JIT for ARM, from Shubham Bansal.

17) Add Huawei hinic ethernet driver.

18) Allow to report MD5 keys in TCP inet_diag dumps, from Ivan
    Delalande.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (1780 commits)
  i40e: point wb_desc at the nvm_wb_desc during i40e_read_nvm_aq
  i40e: avoid NVM acquire deadlock during NVM update
  drivers: net: xgene: Remove return statement from void function
  drivers: net: xgene: Configure tx/rx delay for ACPI
  drivers: net: xgene: Read tx/rx delay for ACPI
  rocker: fix kcalloc parameter order
  rds: Fix non-atomic operation on shared flag variable
  net: sched: don't use GFP_KERNEL under spin lock
  vhost_net: correctly check tx avail during rx busy polling
  net: mdio-mux: add mdio_mux parameter to mdio_mux_init()
  rxrpc: Make service connection lookup always check for retry
  net: stmmac: Delete dead code for MDIO registration
  gianfar: Fix Tx flow control deactivation
  cxgb4: Ignore MPS_TX_INT_CAUSE[Bubble] for T6
  cxgb4: Fix pause frame count in t4_get_port_stats
  cxgb4: fix memory leak
  tun: rename generic_xdp to skb_xdp
  tun: reserve extra headroom only when XDP is set
  net: dsa: bcm_sf2: Configure IMP port TC2QOS mapping
  net: dsa: bcm_sf2: Advertise number of egress queues
  ...
2017-09-06 14:45:08 -07:00
Daniel Díaz
f15d5e6dba tools lib bpf: Fix double file test in Makefile
The Makefile verifies the same file exists twice:
  test -f ../../../include/uapi/linux/bpf.h -a \
       -f ../../../include/uapi/linux/bpf.h

The purpose of the check is to ensure the diff (immediately after the
test) doesn't fail with these two files:

  tools/include/uapi/linux/bpf.h
  include/uapi/linux/bpf.h

Same recipe for bpf_common:
  test -f ../../../include/uapi/linux/bpf_common.h -a \
       -f ../../../include/uapi/linux/bpf_common.h

This corrects the location of the tests.

Signed-off-by: Daniel Díaz <daniel.diaz@linaro.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1502814810-960-1-git-send-email-daniel.diaz@linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-08-17 16:39:14 -03:00
Ingo Molnar
8255e1efc1 perf build: Clarify open-coded header version warning message
In this patch we changed the header checks:

  perf build: Clarify header version warning message

Unfortunately the header checks were copied to various places and thus the message got
out of sync. Fix some of them here.

Note that there's still old, misleading messages remaining in:

  tools/objtool/Makefile: || echo "warning: objtool: x86 instruction decoder differs from kernel" >&2 )) || true
  tools/objtool/Makefile: || echo "warning: objtool: orc_types.h differs from kernel" >&2 )) || true

here objtool copied the perf message, plus:

 tools/perf/util/intel-pt-decoder/Build: || echo "Warning: Intel PT: x86 instruction decoder differs from kernel" >&2 )) || true

here the PT code regressed over the original message and only emits a vague warning
instead of specific file names...

All of this should be consolidated into tools/Build/ and used in a consistent
manner.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: David Carrillo-Cisneros <davidcc@google.com>
Cc: Francis Deslauriers <francis.deslauriers@efficios.com>
Cc: Geneviève Bastien <gbastien@versatic.net>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Julien Desfossez <jdesfossez@efficios.com>
Cc: Martin Liška <mliska@suse.cz>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Turner <pjt@google.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Simon Que <sque@chromium.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Taeung Song <treeze.taeung@gmail.com>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/20170730095130.bblldwxjz5hamybb@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2017-07-31 10:30:06 -03:00
Jakub Kicinski
eb54e522a0 bpf: install libbpf headers on 'make install'
Add a new target to install the bpf.h header to $(prefix)/include/bpf/
directory.  This is necessary to build standalone applications using
libbpf, without the need to clone the kernel sources and point to them.

Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-26 13:42:09 -07:00
Masahiro Yamada
505d3085d7 scripts/spelling.txt: add "overide" pattern and fix typo instances
Fix typos and add the following to the scripts/spelling.txt:

  overide||override

While we are here, fix the doubled "address" in the touched line
Documentation/devicetree/bindings/regulator/ti-abb-regulator.txt.

Also, fix the comment block style in the touched hunks in
drivers/media/dvb-frontends/drx39xyj/drx_driver.h.

Link: http://lkml.kernel.org/r/1481573103-11329-21-git-send-email-yamada.masahiro@socionext.com
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-03-09 17:01:09 -08:00
Uwe Kleine-König
e19b7cee02 make use of make variable CURDIR instead of calling pwd
make already provides the current working directory in a variable, so make
use of it instead of forking a shell. Also replace usage of PWD by
CURDIR. PWD is provided by most shells, but not all, so this makes the
build system more robust.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.com>
2016-12-11 12:12:56 +01:00
Arnaldo Carvalho de Melo
971e827bff tools lib bpf: Copy bpf.h and bpf_common.h from the kernel
To allow the build to complete on older systems, where those files are
either not uptodate, lacking some recent additions or not present at
all.

And check if the copy drifts from the kernel, as in this synthetic test:

    BUILD:   Doing 'make -j4' parallel build
  Warning: tools/include/linux/bpf.h differs from kernel
  Warning: tools/include/linux/bpf_common.h differs from kernel

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-5plvi2gq4x469dcyybiu226q@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-07-12 15:20:32 -03:00
Naveen N. Rao
d5ef314035 perf bpf: Fix build breakage due to libbpf
perf build is currently (v4.4-rc5) broken on powerpc:

  bpf.c:28:4: error: #error __NR_bpf not defined. libbpf does not support
  your arch.
   #  error __NR_bpf not defined. libbpf does not support your arch.
      ^

Fix this by including tools/scripts/Makefile.arch for the proper $ARCH
macro. While at it, remove redundant LP64 macro definition.

Also, since libbpf require $(srctree) now, detect the path of srctree
like perf.

Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1452520124-2073-10-git-send-email-wangnan0@huawei.com
[Use tools/scripts/Makefile.arch]
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-11 19:22:21 -03:00
Jiri Olsa
22992a3208 tools bpf: Add *.cmd files clean up
Add *.cmd files to be removed within clean target.

Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/r/1452509693-13452-3-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-11 12:08:30 -03:00
Jiri Olsa
58683600df perf build: Use FEATURE-DUMP in bpf subproject
Using FEATURE-DUMP in bpf subproject for features detection in case bpf
is built via perf. Keeping the current features detection otherwise.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Wang Nan <wangnan0@huawei.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama <pi3orama@163.com>
Link: http://lkml.kernel.org/r/1450893514-9158-6-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2016-01-06 20:11:14 -03:00
Wang Nan
d8ad6a15cc tools lib bpf: Don't do a feature check when cleaning
Before this patch libbpf always do feature check even when cleaning.

For example:

  $ cd kernel/tools/lib/bpf
  $ make

  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...                           bpf: [ on  ]

    CC       libbpf.o
    CC       bpf.o
    LD       libbpf-in.o
    LINK     libbpf.a
    LINK     libbpf.so
  $ make clean
    CLEAN    libbpf
    CLEAN    core-gen
  $ make clean

  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...                           bpf: [ on  ]

    CLEAN    libbpf
    CLEAN    core-gen
  $

Although the first 'make clean' doesn't show feature check result, it
still does the check. No output because check result is similar to
FEATURE-DUMP.libbpf.

This patch uses same method as perf to turn off feature checking when
'make clean'.

Reported-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1448372181-151723-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-25 16:38:13 -03:00
Yunlong Song
0c77c04aa9 tools lib bpf: Change FEATURE-DUMP to FEATURE-DUMP.libbpf
Commit ed63f34c02 ("perf tools: Make perf
depend on libbpf") triggers the build of libbpf when building the perf
tools, dynamically creating FEATURE-DUMP.libbpf.

It failed to update the tools/lib/bpf/.gitignore file to have that
prefix, fix it.

Signed-off-by: Yunlong Song <yunlong.song@huawei.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Wang Nan <wangnan0@huawei.com>
Fixes: 65f041bee7 ("tools lib bpf: Use FEATURE_USER to allow building in the same dir as perf")
Link: http://lkml.kernel.org/r/1446706594-4142-1-git-send-email-yunlong.song@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-05 12:47:51 -03:00
Jiri Olsa
7c422f5572 tools build: Build fixdep helper from perf and basic libs
Adding the fixdep target into the Makefile.include to ease up building of
fixdep helper, that needs to be built before we dive in to the build itself.
The user can invoke the fixdep target to build the helper.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443004442-32660-8-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-28 15:50:55 -03:00
Jiri Olsa
ab6201d09b tools build: Add Makefile.include
To ease up build framework code setup for users.

More shared code will be added in the following patches.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: David Ahern <dsahern@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1443004442-32660-2-git-send-email-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-28 15:50:54 -03:00
Arnaldo Carvalho de Melo
65f041bee7 tools lib bpf: Use FEATURE_USER to allow building in the same dir as perf
When building tools/lib/bpf as part of the tools/perf/ build process,
which will happend when we introduce a patch wiring that up, we end up
stomping on the feature detection caching mechanism, that uses a file in
the output directory (O=) that is shared by libbpf and perf to check if
something changed from one build to another that requires redoing the
feature detection process.

By using the recently introduced FEATURE_USER tools/build/ knob, we can
avoid that:

Before, every make invokation would run the feature detection:

  $ make O=/tmp/build/perf -C tools/perf
  make: Entering directory '/home/git/linux/tools/perf'
  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...                         glibc: [ on  ]
  <SNIP>
  ...                     get_cpuid: [ on  ]
  ...                           bpf: [ on  ]

    GEN      perf-archive
    GEN      perf-with-kcore

  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...                           bpf: [ on  ]
  <SNIP>

After:

  $ make O=/tmp/build/perf -C tools/perf
  make: Entering directory '/home/git/linux/tools/perf'
    BUILD:   Doing 'make -j4' parallel build
  make: Leaving directory '/home/git/linux/tools/perf'
  $

Because we now have two different feature detection state files:

  $ ls -la /tmp/build/perf/FEATURE-DUMP*
  -rw-rw-r--. 1 acme acme 338 Sep 21 17:25 /tmp/build/perf/FEATURE-DUMP
  -rw-rw-r--. 1 acme acme  33 Sep 21 17:25 /tmp/build/perf/FEATURE-DUMP.libbpf
  $

Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: pi3orama@163.com
Fixes: 1b76c13e4b ("bpf tools: Introduce 'bpf' library and add bpf feature check")
Link: http://lkml.kernel.org/n/tip-s6ev9wfqy7pvvs58emys2g90@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-22 10:47:05 -03:00
Arnaldo Carvalho de Melo
20517cd9c5 tools lib bpf: Fix up FEATURE_{TESTS,DISPLAY} usage
When libbpf was introduced it wrongly asked for the "libelf" and "bpf"
feature tests to be performed (via FEATURE_TESTS), while asking that
"libbpf", "libelf-mmap", "libelf-getphdrnum" and "bpf" to have the
result of its respective tests to be displayed (via FEATURE_DISPLAY).

Due to another recently bug fixed in the tools/build/ infrastructure
("tools build: Fixup feature detection display function name") the
results for the entries in the FEATURE_DISPLAY, for this case, were
appearing as all succeeding, when two of them (the ones only on the
DISPLAY) were not even being performed.

Before:

  $ make -C tools/lib/bpf/
  make: Entering directory '/home/git/linux/tools/lib/bpf'
  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...             libelf-getphdrnum: [ OFF ]
  ...                   libelf-mmap: [ OFF ]
  ...                           bpf: [ on  ]
  <SNIP>

After, with FEATURE_TESTS == FEATURE_DISPLAY:

  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...             libelf-getphdrnum: [ on  ]
  ...                   libelf-mmap: [ on  ]
  ...                           bpf: [ on  ]
  <SNIP>

I just inverted, so that it tests the four features but displays just
the libelf and mmap ones, to make it more compact. So it becomes:

  $ make -C tools/lib/bpf/
  make: Entering directory '/home/git/linux/tools/lib/bpf'

  Auto-detecting system features:
  ...                        libelf: [ on  ]
  ...                           bpf: [ on  ]

Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Borislav Petkov <bp@suse.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: pi3orama@163.com
Fixes: 1b76c13e4b ("bpf tools: Introduce 'bpf' library and add bpf feature check")
Link: http://lkml.kernel.org/n/tip-y4bd59e6j9rzzojiyeqrg2jq@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-09-22 10:47:01 -03:00
Wang Nan
1b76c13e4b bpf tools: Introduce 'bpf' library and add bpf feature check
This is the first patch of libbpf. The goal of libbpf is to create a
standard way for accessing eBPF object files. This patch creates
'Makefile' and 'Build' for it, allows 'make' to build libbpf.a and
libbpf.so, 'make install' to put them into proper directories.
Most part of Makefile is borrowed from traceevent.

Before building, it checks the existence of libelf in Makefile, and deny
to build if not found. Instead of throwing an error if libelf not found,
the error raises in a phony target "elfdep". This design is to ensure
'make clean' still workable even if libelf is not found.

Because libbpf requires 'kern_version' field set for 'union bpf_attr'
(bpfdep" is used for that dependency), Kernel BPF API is also checked
by intruducing a new feature check 'bpf' into tools/build/feature,
which checks the existence and version of linux/bpf.h. When building
libbpf, it searches that file from include/uapi/linux in kernel source
tree (controlled by FEATURE_CHECK_CFLAGS-bpf). Since it searches kernel
source tree it reside, installing of newest kernel headers is not
required, except we are trying to port these files to an old kernel.

To avoid checking that file when perf building, the newly introduced
'bpf' feature check doesn't added into FEATURE_TESTS and
FEATURE_DISPLAY by default in tools/build/Makefile.feature, but added
into libbpf's specific.

Signed-off-by: Wang Nan <wangnan0@huawei.com>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Cc: Brendan Gregg <brendan.d.gregg@gmail.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: David Ahern <dsahern@gmail.com>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Zefan Li <lizefan@huawei.com>
Bcc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1435716878-189507-4-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-08-07 10:16:56 -03:00