tools/mdflush: Fix CI build failure

libbpf-tools: Add experimental BTFGen integration

Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>

Use save_min_core_btf() to uncompress and save the BTF file for the
current system. If the file is available, then use it when opening the
object.

Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>

This commit adds an experimental BTFGen[0] integration to allow some of
the libbpf-tools to run in systems that don't provide BTF information.

The whole process consist of two parts: (1) generating and embedding the
BTF file within the tools binary and (2) using those when the tool is
run.

The first part is done by using the Makefile, it generates the reduced
BTF files for the different eBPF objects of the tools, those files are
then compressed and a C header file with its content is created.

The second part is handled by a new C file that provides the logic to
uncompress and save the BTF file according to the Linux distribution and
kernel version where the tools is being run.

[0] https://lore.kernel.org/bpf/20220215225856.671072-1-mauricio@kinvolk.io/



Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>

bpftool now has a mirror on Github[0], let's pull it as a submodule
and compile when needed instead of shipping the bpftool binary directly.

[0]: https://github.com/libbpf/bpftool



Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io>

Fix test_bcc_fedora CI failure

libbpf-tools: improve fentry_exists check

add tcp congestion control status duration statistic tool, and it can be used to evaluate the networking and congestion algorithm performance.

On architectures that lack support for fentry programs, tools should
fall back to using kprobes even if the kernel version is new enough to
include BPF_TRACE_FENTRY, but fentry_exists() cannot currently detect
this case.

Instead of searching for BPF_TRACE_FENTRY, verify that attaching a
BPF_TRACE_FENTRY program can actually succeed. Rename fentry_exists to
fentry_can_attach to reflect this change.

Signed-off-by: Connor O'Brien <connoro@google.com>
Change-Id: I5ad0341cb060c7a4a2ee17245337170963dfefad

Sync with latest libbpf repo. The sync'ed top libbpf repo
commit is:
  67a4b1464349 ci: remove subprogs from 5.5 whitelist

Signed-off-by: Yonghong Song <yhs@fb.com>

As reported in #3913, vfs_fsync is never triggered when fsync is called.
Use vfscount can reveal that:

    sudo python3 ./vfscount.py
    Tracing... Ctrl-C to end.
    ^C
    ADDR             FUNC                          COUNT
    ffffffff8ad23621 b'vfs_writev'                     2
    ffffffff8ad29df1 b'vfs_getattr_nosec'             55
    ffffffff8ad20401 b'vfs_open'                      58
    ffffffff8ad2a7b1 b'vfs_statx'                     91
    ffffffff8ad641d1 b'vfs_fsync_range'             1802
    ffffffff8ad22111 b'vfs_read'                    1900
    ffffffff8ad22551 b'vfs_write'                   3752

Let's use vfs_fsync_range instead to trace fsync operations.

Closes #3913.

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>

libbpf-tools: convert BCC tcpsynbl to BPF CO-RE version

usdt: support xmm registers as args for x64

Support for using xmm registers for USDT args was added to systemtap in
early 2021 (commit 04c99d0d0267f574fa60044c96933b0dd3846aa1 added xmm0-7
and eaa15b047688175a94e3ae796529785a3a0af208 added xmm8-15). As a result
these registers are showing up in probe descriptors on Fedora.

pthread_start probe description on Ubuntu 20.04:
```
  stapsdt              0x00000052       NT_STAPSDT (SystemTap probe descriptors)
    Provider: libpthread
    Name: pthread_start
    Location: 0x00000000000095e9, Base: 0x000000000001922c, Semaphore: 0x0000000000000000
    Arguments: 8@%rax 8@1600(%rax) 8@1608(%rax)
```

And in the Fedora test container:
```

```
  stapsdt              0x00000053       NT_STAPSDT (SystemTap probe descriptors)
    Provider: libpthread
    Name: pthread_start
    Location: 0x0000000000009280, Base: 0x0000000000016cbc, Semaphore: 0x0000000000000000
    Arguments: 8@%xmm0 8@1600(%rax) 8@1608(%rax)
```

bcc doesn't recognize these registers so it's unable to generate code to fetch arguments which use these registers for storage. Add support for XMM0-15

.

This should fix `lib/uthreads.py` test, which uses `pthread_start` and therefore fails to generate program on Fedora.

Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>

commit 531b698c ("libbpf-tools: Enable compilation warnings for
BPF programs") applies CFLAGS to all targets. However, some of the c
flags typically used by distribution are not available to the bpf
target. Add a new BPFCFLAGS macro to take care of that.

Fixes the following compilation error on fedora:

  BPF      bashreadline.bpf.o
clang-13: warning: optimization flag '-ffat-lto-objects' is not supported [-Wignored-optimization-argument]
clang-13: warning: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-hardened-cc1' [-Wunused-command-line-argument]
clang-13: warning: argument unused during compilation: '-specs=/usr/lib/rpm/redhat/redhat-annobin-cc1' [-Wunused-command-line-argument]
clang-13: warning: argument unused during compilation: '-fstack-clash-protection' [-Wunused-command-line-argument]
error: option 'cf-protection=return' cannot be specified on this target
error: option 'cf-protection=branch' cannot be specified on this target
2 errors generated.

btf__get_map_kv_tids() is deprecated and causes annoying compilation warnings.
Reimplement it in BCC.

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>

llvm upstream patch https://reviews.llvm.org/D118652


did some header file cleanup and this breaks bcc with llvm15
with the following compilation error:

  /.../src/cc/bpf_module.cc: In member function ‘void ebpf::BPFModule::dump_ir(llvm::Module&)’:
  /.../src/cc/bpf_module.cc:231:39: error: no matching function for call to ‘llvm::legacy::PassManager::add(llvm::Module Pass*)’
   PM.add(createPrintModulePass(errs()));
                                       ^
  In file included from /.../src/cc/bpf_module.cc:25:
  /.../include/llvm/IR/LegacyPassManager.h:58:8: note: candidate: ‘virtual void llvm::legacy::PassManager::add(llvm::Pass*)’
     void add(Pass *P) override;
          ^~~
  /.../include/llvm/IR/LegacyPassManager.h:58:8: note:   no known conversion for argument 1 from ‘llvm::ModulePass*’ to ‘llvm::Pass*’

Adding the include path "llvm/Pass.h" in bpf_module.cc fixed the issue.

Signed-off-by: Yonghong Song <yhs@fb.com>

The tool cachestat is broken on kernel 5.15 due to kernel function
renaming. Fix the tool by detecting symbol existence. See #3687 and
 #3692.

Signed-off-by: Hengqi Chen <chenhengqi@outlook.com>

During 5.17 dev cycle, the kernel dropped request->rq_disk. It can now be
accessed through request->q->disk. Fix the python ones in tools/. There are
more usages in other places which need to be fixed too.

Signed-off-by: Tejun Heo <tj@kernel.org>

Tested seem to work.