Re: [GIT PULL 00/24] perf/ebpf lib + llvm/clang building infrastructure

[Ingo Molnar <mingo@kernel.org>]

* Arnaldo Carvalho de Melo <acme@kernel.org> wrote:

> Hi Ingo,
> 
> 	This is up to a test that checks that the infrastructure for getting
> a C source file and build it to a form that can then be used to upload it to
> the kernel is working.
> 
> 	Wang has a tree where we go all the way to passing a .c file as an
> --event, but I thought about breaking the patchkit up to what is settled and
> the "perf test -v LLVM" point looks like a good cutoff point for demoing/testing
> what is in this patchkit.

Fair enough!

> 	It shouldn't affect people without the environment needed, as well it 
> should check the environment for sanity and provide info about how to get it 
> working, be it in the changeset logs, the docs and on tool output messages.o
> 
> 	If you find anything in it that needs fixing, please let us know if you
> think we should fix it before merging it to this point or if something can be
> fixed in follow up patches.
> 
> 	Wang's repo, rebased, almost builds, he should be refreshing this soon,
> fixing those trailing whitespace issues, that is stopping the rebase here:
> 
>   [acme@zoo linux]$ git remote -v | grep wang | head -1
>   wangnan.github	https://github.com/WangNan0/linux.git (fetch)
>   [acme@zoo linux]$ git checkout -b ebpf-test wangnan.github/ebpf
>   Branch ebpf-test set up to track remote branch ebpf from wangnan.github.
>   Switched to a new branch 'ebpf-test'
>   [acme@zoo linux]$ git rebase perf/ebpf
>   First, rewinding head to replay your work on top of it...
>   Applying: perf tests: Add LLVM test for eBPF on-the-fly compiling
>   Using index info to reconstruct a base tree...
>   M	tools/perf/tests/Build
>   M 	tools/perf/tests/builtin-test.c
>   M	tools/perf/tests/tests.h
>   M	tools/perf/util/llvm-utils.c
>   M	tools/perf/util/llvm-utils.h
>   Falling back to patching base and 3-way merge...
>   No changes -- Patch already applied.
>   Applying: perf tools: Make perf depend on libbpf
>   Using index info to reconstruct a base tree...
>   M	tools/perf/MANIFEST
>   Falling back to patching base and 3-way merge...
>   Auto-merging tools/perf/MANIFEST
>   Applying: perf ebpf: Add the libbpf glue
>   Applying: perf tools: Enable passing bpf object file to --event
>   Applying: perf tools: Parse probe points of eBPF programs during preparation
>   Applying: perf probe: Attach trace_probe_event with perf_probe_event
>   Applying: perf record: Probe at kprobe points
>   Applying: perf record: Load all eBPF object into kernel
>   Applying: perf tools: Add bpf_fd field to evsel and config it
>   Applying: perf tools: Attach eBPF program to perf event
>   Applying: perf tools: Suppress probing messages when probing by BPF loading
>   Applying: perf record: Add clang options for compiling BPF scripts
>   Applying: perf tools: Infrastructure for compiling scriptlets when passing '.c' to --event
>   Applying: perf tests: Enforce LLVM test for BPF test
>   Applying: perf test: Enable 'perf test' run as test targets
>   tools/perf/tests/builtin-test.c:279: trailing whitespace.
>   +			/* 
>   [acme@zoo linux]$
> 
> 	After that whitespace thing is fixed, you'll get to a point where 'perf
> test -v BPF' will show you all the steps involved in, from a .c file do all the
> build process and loading, attaching to a kprobe, etc that we discussed, but
> those extra patches need more working before I can submit to you.
> 
> 	Otherwise, please consider pulling,
> 
> - Arnaldo
> 
> The following changes since commit 1354ac6ad84395660f551d0614a6ca39e5bfe8e3:
> 
>   Merge tag 'perf-core-for-mingo' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core (2015-08-07 09:11:30 +0200)
> 
> are available in the git repository at:
> 
>   git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git tags/perf-ebpf-for-mingo
> 
> for you to fetch changes up to 9bc898c7019383b6aa2ae6cb2928c4ca926449f0:
> 
>   perf tests: Add LLVM test for eBPF on-the-fly compiling (2015-08-07 10:57:24 -0300)
> 
> ----------------------------------------------------------------
> perf/ebpf library + llvm/clang infrastructure
> 
> Infrastructure:
> 
> - library for interfacing with the kernel eBPF infrastructure, with
>   tools/perf/ targeted as a first user (Wang Nan)
> 
> - llvm/clang infrastructure for building BPF object files from C source
>   code (Wang Nan)
> 
> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
> 
> ----------------------------------------------------------------
> Wang Nan (24):
>       bpf tools: Introduce 'bpf' library and add bpf feature check
>       bpf tools: Allow caller to set printing function
>       bpf tools: Open eBPF object file and do basic validation
>       bpf tools: Read eBPF object from buffer
>       bpf tools: Check endianness and make libbpf fail early
>       bpf tools: Iterate over ELF sections to collect information
>       bpf tools: Collect version and license from ELF sections
>       bpf tools: Collect map definitions from 'maps' section
>       bpf tools: Collect symbol table from SHT_SYMTAB section
>       bpf tools: Collect eBPF programs from their own sections
>       bpf tools: Collect relocation sections from SHT_REL sections
>       bpf tools: Record map accessing instructions for each program
>       bpf tools: Add bpf.c/h for common bpf operations
>       bpf tools: Create eBPF maps defined in an object file
>       bpf tools: Relocate eBPF programs
>       bpf tools: Introduce bpf_load_program() to bpf.c
>       bpf tools: Load eBPF programs in object files into kernel
>       bpf tools: Introduce accessors for struct bpf_program
>       bpf tools: Link all bpf objects onto a list
>       perf tools: Introduce llvm config options
>       perf tools: Call clang to compile C source to object code
>       perf tools: Auto detecting kernel build directory
>       perf tools: Auto detecting kernel include options
>       perf tests: Add LLVM test for eBPF on-the-fly compiling
> 
>  tools/build/feature/Makefile    |    6 +-
>  tools/build/feature/test-bpf.c  |   18 +
>  tools/lib/bpf/.gitignore        |    2 +
>  tools/lib/bpf/Build             |    1 +
>  tools/lib/bpf/Makefile          |  195 ++++++++
>  tools/lib/bpf/bpf.c             |   85 ++++
>  tools/lib/bpf/bpf.h             |   23 +
>  tools/lib/bpf/libbpf.c          | 1037 +++++++++++++++++++++++++++++++++++++++
>  tools/lib/bpf/libbpf.h          |   81 +++
>  tools/perf/MANIFEST             |    1 +
>  tools/perf/tests/Build          |    1 +
>  tools/perf/tests/builtin-test.c |    4 +
>  tools/perf/tests/llvm.c         |   98 ++++
>  tools/perf/tests/tests.h        |    1 +
>  tools/perf/util/Build           |    1 +
>  tools/perf/util/config.c        |    4 +
>  tools/perf/util/llvm-utils.c    |  408 +++++++++++++++
>  tools/perf/util/llvm-utils.h    |   49 ++
>  18 files changed, 2014 insertions(+), 1 deletion(-)
>  create mode 100644 tools/build/feature/test-bpf.c
>  create mode 100644 tools/lib/bpf/.gitignore
>  create mode 100644 tools/lib/bpf/Build
>  create mode 100644 tools/lib/bpf/Makefile
>  create mode 100644 tools/lib/bpf/bpf.c
>  create mode 100644 tools/lib/bpf/bpf.h
>  create mode 100644 tools/lib/bpf/libbpf.c
>  create mode 100644 tools/lib/bpf/libbpf.h
>  create mode 100644 tools/perf/tests/llvm.c
>  create mode 100644 tools/perf/util/llvm-utils.c
>  create mode 100644 tools/perf/util/llvm-utils.h

Pulled, thanks a lot Arnaldo!

	Ingo