linux.git/tools/testing/selftests/bpf/Makefile, branch v5.13

Merge tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

2021-04-29T21:24:39+00:00

Pull Kbuild updates from Masahiro Yamada:

 - Evaluate $(call cc-option,...) etc. only for build targets

 - Add CONFIG_VMLINUX_MAP to generate .map file when linking vmlinux

 - Remove unnecessary --gcc-toolchains Clang flag because the --prefix
   flag finds the toolchains

 - Do not pass Clang's --prefix flag when using the integrated as

 - Check the assembler version in Kconfig time

 - Add new CONFIG options, AS_VERSION, AS_IS_GNU, AS_IS_LLVM to clean up
   some dependencies in Kconfig

 - Fix invalid Module.symvers creation when building only modules
   without vmlinux

 - Fix false-positive modpost warnings when CONFIG_TRIM_UNUSED_KSYMS is
   set, but there is no module to build

 - Refactor module installation Makefile

 - Support zstd for module compression

 - Convert alpha and ia64 to use generic shell scripts to generate the
   syscall headers

 - Add a new elfnote to indicate if the kernel was built with LTO, which
   will be used by pahole

 - Flatten the directory structure under include/config/ so CONFIG
   options and filenames match

 - Change the deb source package name from linux-$(KERNELRELEASE) to
   linux-upstream

* tag 'kbuild-v5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (42 commits)
  kbuild: Add $(KBUILD_HOSTLDFLAGS) to 'has_libelf' test
  kbuild: deb-pkg: change the source package name to linux-upstream
  tools: do not include scripts/Kbuild.include
  kbuild: redo fake deps at include/config/*.h
  kbuild: remove TMPO from try-run
  MAINTAINERS: add pattern for dummy-tools
  kbuild: add an elfnote for whether vmlinux is built with lto
  ia64: syscalls: switch to generic syscallhdr.sh
  ia64: syscalls: switch to generic syscalltbl.sh
  alpha: syscalls: switch to generic syscallhdr.sh
  alpha: syscalls: switch to generic syscalltbl.sh
  sysctl: use min() helper for namecmp()
  kbuild: add support for zstd compressed modules
  kbuild: remove CONFIG_MODULE_COMPRESS
  kbuild: merge scripts/Makefile.modsign to scripts/Makefile.modinst
  kbuild: move module strip/compression code into scripts/Makefile.modinst
  kbuild: refactor scripts/Makefile.modinst
  kbuild: rename extmod-prefix to extmod_prefix
  kbuild: check module name conflict for external modules as well
  kbuild: show the target directory for depmod log
  ...

tools: do not include scripts/Kbuild.include

2021-04-24T20:26:13+00:00

Since commit 57fd251c7896 ("kbuild: split cc-option and friends to
scripts/Makefile.compiler"), some kselftests fail to build.

The tools/ directory opted out Kbuild, and went in a different
direction. People copied scripts and Makefiles to the tools/ directory
to create their own build system.

tools/build/Build.include mimics scripts/Kbuild.include, but some
tool Makefiles include the Kbuild one to import a feature that is
missing in tools/build/Build.include:

 - Commit ec04aa3ae87b ("tools/thermal: tmon: use "-fstack-protector"
   only if supported") included scripts/Kbuild.include from
   tools/thermal/tmon/Makefile to import the cc-option macro.

 - Commit c2390f16fc5b ("selftests: kvm: fix for compilers that do
   not support -no-pie") included scripts/Kbuild.include from
   tools/testing/selftests/kvm/Makefile to import the try-run macro.

 - Commit 9cae4ace80ef ("selftests/bpf: do not ignore clang
   failures") included scripts/Kbuild.include from
   tools/testing/selftests/bpf/Makefile to import the .DELETE_ON_ERROR
   target.

 - Commit 0695f8bca93e ("selftests/powerpc: Handle Makefile for
   unrecognized option") included scripts/Kbuild.include from
   tools/testing/selftests/powerpc/pmu/ebb/Makefile to import the
   try-run macro.

Copy what they need into tools/build/Build.include, and make them
include it instead of scripts/Kbuild.include.

Link: https://lore.kernel.org/lkml/86dadf33-70f7-a5ac-cb8c-64966d2f45a1@linux.ibm.com/
Fixes: 57fd251c7896 ("kbuild: split cc-option and friends to scripts/Makefile.compiler")
Reported-by: Janosch Frank 
Reported-by: Christian Borntraeger 
Signed-off-by: Masahiro Yamada 
Tested-by: Christian Borntraeger 
Acked-by: Yonghong Song

selftests/bpf: Add map linking selftest

2021-04-23T21:05:27+00:00

Add selftest validating various aspects of statically linking BTF-defined map
definitions. Legacy map definitions do not support extern resolution between
object files. Some of the aspects validated:
  - correct resolution of extern maps against concrete map definitions;
  - extern maps can currently only specify map type and key/value size and/or
    type information;
  - weak concrete map definitions are resolved properly.

Static map definitions are not yet supported by libbpf, so they are not
explicitly tested, though manual testing showes that BPF linker handles them
properly.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20210423181348.1801389-18-andrii@kernel.org

selftests/bpf: Add global variables linking selftest

2021-04-23T21:05:27+00:00

Add selftest validating various aspects of statically linking global
variables:
  - correct resolution of extern variables across .bss, .data, and .rodata
    sections;
  - correct handling of weak definitions;
  - correct de-duplication of repeating special externs (.kconfig, .ksyms).

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20210423181348.1801389-17-andrii@kernel.org

selftests/bpf: Add function linking selftest

2021-04-23T21:05:27+00:00

Add selftest validating various aspects of statically linking functions:
  - no conflicts and correct resolution for name-conflicting static funcs;
  - correct resolution of extern functions;
  - correct handling of weak functions, both resolution itself and libbpf's
    handling of unused weak function that "lost" (it leaves gaps in code with
    no ELF symbols);
  - correct handling of hidden visibility to turn global function into
    "static" for the purpose of BPF verification.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20210423181348.1801389-16-andrii@kernel.org

selftests/bpf: Omit skeleton generation for multi-linked BPF object files

2021-04-23T21:05:27+00:00

Skip generating individual BPF skeletons for files that are supposed to be
linked together to form the final BPF object file. Very often such files are
"incomplete" BPF object files, which will fail libbpf bpf_object__open() step,
if used individually, thus failing BPF skeleton generation. This is by design,
so skip individual BPF skeletons and only validate them as part of their
linked final BPF object file and skeleton.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20210423181348.1801389-15-andrii@kernel.org

selftests/bpf: Use -O0 instead of -Og in selftests builds

2021-04-23T21:05:27+00:00

While -Og is designed to work well with debugger, it's still inferior to -O0
in terms of debuggability experience. It will cause some variables to still be
inlined, it will also prevent single-stepping some statements and otherwise
interfere with debugging experience. So switch to -O0 which turns off any
optimization and provides the best debugging experience.

Signed-off-by: Andrii Nakryiko 
Signed-off-by: Alexei Starovoitov 
Acked-by: Yonghong Song 
Link: https://lore.kernel.org/bpf/20210423181348.1801389-14-andrii@kernel.org

selftests/bpf: Add docs target as all dependency

2021-04-20T22:01:59+00:00

Currently docs target is make dependency for TEST_GEN_FILES,
which makes tests to be rebuilt every time you run make.

Adding docs as all target dependency, so when running make
on top of built selftests it will show just:

  $ make
  make[1]: Nothing to be done for 'docs'.

After cleaning docs, only docs is rebuilt:

  $ make docs-clean
  CLEAN    eBPF_helpers-manpage
  CLEAN    eBPF_syscall-manpage
  $ make
  GEN      ...selftests/bpf/bpf-helpers.rst
  GEN      ...selftests/bpf/bpf-helpers.7
  GEN      ...selftests/bpf/bpf-syscall.rst
  GEN      ...selftests/bpf/bpf-syscall.2
  $ make
  make[1]: Nothing to be done for 'docs'.

Fixes: a01d935b2e09 ("tools/bpf: Remove bpf-helpers from bpftool docs")
Signed-off-by: Jiri Olsa 
Signed-off-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20210420132428.15710-1-jolsa@kernel.org

selftests/bpf: Silence clang compilation warnings

2021-04-15T23:50:22+00:00

With clang compiler:
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
Some linker flags are not used/effective for some binaries and
we have warnings like:
  warning: -lelf: 'linker' input unused [-Wunused-command-line-argument]

We also have warnings like:
  .../selftests/bpf/prog_tests/ns_current_pid_tgid.c:74:57: note: treat the string as an argument to avoid this
        if (CHECK(waitpid(cpid, &wstatus, 0) == -1, "waitpid", strerror(errno)))
                                                               ^
                                                               "%s",
  .../selftests/bpf/test_progs.h:129:35: note: expanded from macro 'CHECK'
        _CHECK(condition, tag, duration, format)
                                         ^
  .../selftests/bpf/test_progs.h:108:21: note: expanded from macro '_CHECK'
                fprintf(stdout, ##format);                              \
                                  ^
The first warning can be silenced with clang option -Wno-unused-command-line-argument.
For the second warning, source codes are modified as suggested by the compiler
to silence the warning. Since gcc does not support the option
-Wno-unused-command-line-argument and the warning only happens with clang
compiler, the option -Wno-unused-command-line-argument is enabled only when
clang compiler is used.

Signed-off-by: Yonghong Song 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20210413153429.3029377-1-yhs@fb.com

selftests/bpf: Fix test_cpp compilation failure with clang

2021-04-15T23:50:22+00:00

With clang compiler:
  make -j60 LLVM=1 LLVM_IAS=1  <=== compile kernel
  make -j60 -C tools/testing/selftests/bpf LLVM=1 LLVM_IAS=1
the test_cpp build failed due to the failure:
  warning: treating 'c-header' input as 'c++-header' when in C++ mode, this behavior is deprecated [-Wdeprecated]
  clang-13: error: cannot specify -o when generating multiple output files

test_cpp compilation flag looks like:
  clang++ -g -Og -rdynamic -Wall -I<...> ... \
  -Dbpf_prog_load=bpf_prog_test_load -Dbpf_load_program=bpf_test_load_program \
  test_cpp.cpp <...>/test_core_extern.skel.h <...>/libbpf.a <...>/test_stub.o \
  -lcap -lelf -lz -lrt -lpthread -o <...>/test_cpp

The clang++ compiler complains the header file in the command line and
also failed the compilation due to this.
Let us remove the header file from the command line which is not intended
any way, and this fixed the compilation problem.

Signed-off-by: Yonghong Song 
Signed-off-by: Alexei Starovoitov 
Acked-by: Andrii Nakryiko 
Link: https://lore.kernel.org/bpf/20210413153424.3028986-1-yhs@fb.com