linux-stable.git/tools/lib/bpf/Makefile, branch linux-5.4.y

libbpf: Fix INSTALL flag order

2021-03-30T12:35:24+00:00

[ Upstream commit e7fb6465d4c8e767e39cbee72464e0060ab3d20c ]

It was reported ([0]) that having optional -m flag between source and
destination arguments in install command breaks bpftools cross-build
on MacOS. Move -m to the front to fix this issue.

  [0] https://github.com/openwrt/openwrt/pull/3959

Fixes: 7110d80d53f4 ("libbpf: Makefile set specified permission mode")
Signed-off-by: Georgi Valkov 
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Link: https://lore.kernel.org/bpf/20210308183038.613432-1-andrii@kernel.org
Signed-off-by: Sasha Levin

libbpf: Remove arch-specific include path in Makefile

2020-10-07T06:01:25+00:00

[ Upstream commit 21e9ba5373fc2cec608fd68301a1dbfd14df3172 ]

Ubuntu mainline builds for ppc64le are failing with the below error (*):
    CALL    /home/kernel/COD/linux/scripts/atomic/check-atomics.sh
    DESCEND  bpf/resolve_btfids

  Auto-detecting system features:
  ...                        libelf: [ [32mon[m  ]
  ...                          zlib: [ [32mon[m  ]
  ...                           bpf: [ [31mOFF[m ]

  BPF API too old
  make[6]: *** [Makefile:295: bpfdep] Error 1
  make[5]: *** [Makefile:54: /home/kernel/COD/linux/debian/build/build-generic/tools/bpf/resolve_btfids//libbpf.a] Error 2
  make[4]: *** [Makefile:71: bpf/resolve_btfids] Error 2
  make[3]: *** [/home/kernel/COD/linux/Makefile:1890: tools/bpf/resolve_btfids] Error 2
  make[2]: *** [/home/kernel/COD/linux/Makefile:335: __build_one_by_one] Error 2
  make[2]: Leaving directory '/home/kernel/COD/linux/debian/build/build-generic'
  make[1]: *** [Makefile:185: __sub-make] Error 2
  make[1]: Leaving directory '/home/kernel/COD/linux'

resolve_btfids needs to be build as a host binary and it needs libbpf.
However, libbpf Makefile hardcodes an include path utilizing $(ARCH).
This results in mixing of cross-architecture headers resulting in a
build failure.

The specific header include path doesn't seem necessary for a libbpf
build. Hence, remove the same.

(*) https://kernel.ubuntu.com/~kernel-ppa/mainline/v5.9-rc3/ppc64el/log

Reported-by: Vaidyanathan Srinivasan 
Signed-off-by: Naveen N. Rao 
Signed-off-by: Daniel Borkmann 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20200902084246.1513055-1-naveen.n.rao@linux.vnet.ibm.com
Signed-off-by: Sasha Levin

libbpf: Fix readelf output parsing for Fedora

2020-05-10T08:31:32+00:00

commit aa915931ac3e53ccf371308e6750da510e3591dd upstream.

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] https://src.fedoraproject.org/rpms/binutils/c/b8265c46f7ddae23a792ee8306fbaaeacba83bf8

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: 3464afdf11f9 (libbpf: Fix readelf output parsing on powerpc with recent binutils)
Reported-by: Justin Forbes 
Signed-off-by: Thadeu Lima de Souza Cascardo 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Cc: Aurelien Jarno 
Link: https://lore.kernel.org/bpf/20191213101114.GA3986@calabresa
Signed-off-by: Greg Kroah-Hartman

libbpf: Fix readelf output parsing on powerpc with recent binutils

2020-04-29T14:33:04+00:00

[ Upstream commit 3464afdf11f9a1e031e7858a05351ceca1792fea ]

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 [: 8]     1 btf_is_struct

The extra "[: 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 
Signed-off-by: Daniel Borkmann 
Tested-by: Michael Ellerman 
Link: https://lore.kernel.org/bpf/20191201195728.4161537-1-aurelien@aurel32.net
Signed-off-by: Sasha Levin

libbpf: Fix Makefile' libbpf symbol mismatch diagnostic

2020-01-17T18:48:41+00:00

commit b568405856906ee4d9ba6284fd36f2928653a623 upstream.

Fix Makefile's diagnostic diff output when there is LIBBPF_API-versioned
symbols mismatch.

Fixes: 1bd63524593b ("libbpf: handle symbol versioning properly for libbpf.a")
Signed-off-by: Andrii Nakryiko 
Signed-off-by: Daniel Borkmann 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20191127200134.1360660-1-andriin@fb.com
Signed-off-by: Greg Kroah-Hartman

libbpf: handle symbol versioning properly for libbpf.a

2019-09-30T22:19:45+00:00

bcc uses libbpf repo as a submodule. It brings in libbpf source
code and builds everything together to produce shared libraries.
With latest libbpf, I got the following errors:
  /bin/ld: libbcc_bpf.so.0.10.0: version node not found for symbol xsk_umem__create@LIBBPF_0.0.2
  /bin/ld: failed to set dynamic section sizes: Bad value
  collect2: error: ld returned 1 exit status
  make[2]: *** [src/cc/libbcc_bpf.so.0.10.0] Error 1

In xsk.c, we have
  asm(".symver xsk_umem__create_v0_0_2, xsk_umem__create@LIBBPF_0.0.2");
  asm(".symver xsk_umem__create_v0_0_4, xsk_umem__create@@LIBBPF_0.0.4");
The linker thinks the built is for LIBBPF but cannot find proper version
LIBBPF_0.0.2/4, so emit errors.

I also confirmed that using libbpf.a to produce a shared library also
has issues:
  -bash-4.4$ cat t.c
  extern void *xsk_umem__create;
  void * test() { return xsk_umem__create; }
  -bash-4.4$ gcc -c -fPIC t.c
  -bash-4.4$ gcc -shared t.o libbpf.a -o t.so
  /bin/ld: t.so: version node not found for symbol xsk_umem__create@LIBBPF_0.0.2
  /bin/ld: failed to set dynamic section sizes: Bad value
  collect2: error: ld returned 1 exit status
  -bash-4.4$

Symbol versioning does happens in commonly used libraries, e.g., elfutils
and glibc. For static libraries, for a versioned symbol, the old definitions
will be ignored, and the symbol will be an alias to the latest definition.
For example, glibc sched_setaffinity is versioned.
  -bash-4.4$ readelf -s /usr/lib64/libc.so.6 | grep sched_setaffinity
     756: 000000000013d3d0    13 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@GLIBC_2.3.3
     757: 00000000000e2e70   455 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@@GLIBC_2.3.4
    1800: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS sched_setaffinity.c
    4228: 00000000000e2e70   455 FUNC    LOCAL  DEFAULT   13 __sched_setaffinity_new
    4648: 000000000013d3d0    13 FUNC    LOCAL  DEFAULT   13 __sched_setaffinity_old
    7338: 000000000013d3d0    13 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@GLIBC_2
    7380: 00000000000e2e70   455 FUNC    GLOBAL DEFAULT   13 sched_setaffinity@@GLIBC_
  -bash-4.4$
For static library, the definition of sched_setaffinity aliases to the new definition.
  -bash-4.4$ readelf -s /usr/lib64/libc.a | grep sched_setaffinity
  File: /usr/lib64/libc.a(sched_setaffinity.o)
     8: 0000000000000000   455 FUNC    GLOBAL DEFAULT    1 __sched_setaffinity_new
    12: 0000000000000000   455 FUNC    WEAK   DEFAULT    1 sched_setaffinity

For both elfutils and glibc, additional macros are used to control different handling
of symbol versioning w.r.t static and shared libraries.
For elfutils, the macro is SYMBOL_VERSIONING
(https://sourceware.org/git/?p=elfutils.git;a=blob;f=lib/eu-config.h).
For glibc, the macro is SHARED
(https://sourceware.org/git/?p=glibc.git;a=blob;f=include/shlib-compat.h;hb=refs/heads/master)

This patch used SHARED as the macro name. After this patch, the libbpf.a has
  -bash-4.4$ readelf -s libbpf.a | grep xsk_umem__create
     372: 0000000000017145  1190 FUNC    GLOBAL DEFAULT    1 xsk_umem__create_v0_0_4
     405: 0000000000017145  1190 FUNC    GLOBAL DEFAULT    1 xsk_umem__create
     499: 00000000000175eb   103 FUNC    GLOBAL DEFAULT    1 xsk_umem__create_v0_0_2
  -bash-4.4$
No versioned symbols for xsk_umem__create.
The libbpf.a can be used to build a shared library succesfully.
  -bash-4.4$ cat t.c
  extern void *xsk_umem__create;
  void * test() { return xsk_umem__create; }
  -bash-4.4$ gcc -c -fPIC t.c
  -bash-4.4$ gcc -shared t.o libbpf.a -o t.so
  -bash-4.4$

Fixes: 10d30e301732 ("libbpf: add flags to umem config")
Cc: Kevin Laatz 
Cc: Arnaldo Carvalho de Melo 
Cc: Andrii Nakryiko 
Acked-by: Andrii Nakryiko 
Signed-off-by: Yonghong Song 
Signed-off-by: Alexei Starovoitov

tools: bpf: Use !building_out_of_srctree to determine srctree

2019-09-30T08:53:34+00:00

make TARGETS=bpf kselftest fails with:

Makefile:127: tools/build/Makefile.include: No such file or directory

When the bpf tool make is invoked from tools Makefile, srctree is
cleared and the current logic check for srctree equals to empty
string to determine srctree location from CURDIR.

When the build in invoked from selftests/bpf Makefile, the srctree
is set to "." and the same logic used for srctree equals to empty is
needed to determine srctree.

Check building_out_of_srctree undefined as the condition for both
cases to fix "make TARGETS=bpf kselftest" build failure.

Signed-off-by: Shuah Khan 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Link: https://lore.kernel.org/bpf/20190927011344.4695-1-skhan@linuxfoundation.org

libbpf: add flags to umem config

2019-08-30T23:08:26+00:00

This patch adds a 'flags' field to the umem_config and umem_reg structs.
This will allow for more options to be added for configuring umems.

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

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

Signed-off-by: Kevin Laatz 
Signed-off-by: Ciara Loftus 
Acked-by: Jonathan Lemon 
Signed-off-by: Daniel Borkmann

libbpf: use LFS (_FILE_OFFSET_BITS) instead of direct mmap2 syscall

2019-08-21T12:31:17+00:00

Drop __NR_mmap2 fork in flavor of LFS, that is _FILE_OFFSET_BITS=64
(glibc & bionic) / LARGEFILE64_SOURCE (for musl) decision. It allows
mmap() to use 64bit offset that is passed to mmap2 syscall. As result
pgoff is not truncated and no need to use direct access to mmap2 for
32 bits systems.

Signed-off-by: Ivan Khoronzhuk 
Acked-by: Yonghong Song 
Signed-off-by: Daniel Borkmann

libbpf: make libbpf.map source of truth for libbpf version

2019-08-16T00:03:26+00:00

Currently libbpf version is specified in 2 places: libbpf.map and
Makefile. They easily get out of sync and it's very easy to update one,
but forget to update another one. In addition, Github projection of
libbpf has to maintain its own version which has to be remembered to be
kept in sync manually, which is very error-prone approach.

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

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

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

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

Cc: Andrey Ignatov 
Signed-off-by: Andrii Nakryiko 
Acked-by: Andrey Ignatov 
Signed-off-by: Alexei Starovoitov