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Bpftool sync 2022-11-16 #47

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@qmonnet qmonnet commented Nov 16, 2022

Pull latest libbpf from mirror and sync bpftool repo with kernel, up to the commits used for libbpf sync. This is an automatic update performed by calling the sync script from this repo:

$ ./scripts/sync-kernel.sh . <path/to/>linux

Additionally, add the relevant feature detection probe for the LLVM library which is now the default for disassembling JIT-compiled programs, and update the CI workflow accordingly.

@qmonnet qmonnet force-pushed the bpftool-sync-2022-11-16T14-33-28.872Z branch 3 times, most recently from d0fc02f to e921664 Compare November 16, 2022 22:35
qmonnet and others added 27 commits November 17, 2022 11:35
I believe the developer certificate can also apply to those. Let's
enforce the tag requirement to all bpftool commits. We also remove the
"signature" create by "git format-patch" appending the Git version
number to the cover letter, we don't need it in the commit log.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Pull latest libbpf from mirror.
Libbpf version: 1.1.0
Libbpf commit:  8d358ab94843935302cd21901fb3c45d93c7f05e

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
This updates the perf tool with generic branch type classification with
two new branch types i.e system error (PERF_BR_SERROR) and not in
transaction (PERF_BR_NO_TX) which got updated earlier in the kernel.

This also updates corresponding branch type strings in
branch_type_name().

Committer notes:

At perf tools merge time this is only on PeterZ's tree, at:

  git://git.kernel.org/pub/scm/linux/kernel/git/peterz/queue.git perf/core

So for testing one has to build a kernel with that branch, then test
the tooling side from:

  git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux.git perf/core

Reviewed-by: James Clark <james.clark@arm.com>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220824044822.70230-6-anshuman.khandual@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This updates the perf tool with generic branch type classification with new
ABI extender place holder i.e PERF_BR_EXTEND_ABI, the new 4 bit branch type
field i.e perf_branch_entry.new_type, new generic page fault related branch
types and some arch specific branch types as added earlier in the kernel.

Committer note:

Add an extra entry to the branch_type_name array to cope with
PERF_BR_EXTEND_ABI, to address build warnings on some compiler/systems,
like:

  75     8.89 ubuntu:20.04-x-powerpc64el    : FAIL gcc version 10.3.0 (Ubuntu 10.3.0-1ubuntu1~20.04)
        inlined from 'branch_type_stat_display' at util/branch.c:152:4:
    /usr/powerpc64le-linux-gnu/include/bits/stdio2.h:100:10: error: '%8s' directive argument is null [-Werror=format-overflow=]
      100 |   return __fprintf_chk (__stream, __USE_FORTIFY_LEVEL - 1, __fmt,
          |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
      101 |    __va_arg_pack ());
          |    ~~~~~~~~~~~~~~~~~

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220824044822.70230-7-anshuman.khandual@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This updates the perf tools with branch privilege information request flag
i.e PERF_SAMPLE_BRANCH_PRIV_SAVE that has been added earlier in the kernel.
This also updates 'perf record' documentation, branch_modes[], and generic
branch privilege level enumeration as added earlier in the kernel.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220824044822.70230-8-anshuman.khandual@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
This updates the perf tool with arch specific branch type classification
used for BRBE on arm64 platform as added in the kernel earlier.

Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James Clark <james.clark@arm.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Suzuki Poulouse <suzuki.poulose@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20220824044822.70230-9-anshuman.khandual@arm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
…the kernel

Two new fields for mem_lvl_num has been introduced: PERF_MEM_LVLNUM_IO
and PERF_MEM_LVLNUM_CXL which are required to support perf mem/c2c on
AMD platform.

Signed-off-by: Ravi Bangoria <ravi.bangoria@amd.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ali Saidi <alisaidi@amazon.com>
Cc: Ananth Narayan <ananth.narayan@amd.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Joe Mario <jmario@redhat.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Kim Phillips <kim.phillips@amd.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sandipan Das <sandipan.das@amd.com>
Cc: Santosh Shukla <santosh.shukla@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86@kernel.org
Link: https://lore.kernel.org/r/20221006153946.7816-2-ravi.bangoria@amd.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
To pick the changes in:

  cfef80bad4cf79cd ("perf/uapi: Define PERF_MEM_SNOOPX_PEER in kernel header file")
  ee3e88dfec23153d ("perf/mem: Introduce PERF_MEM_LVLNUM_{EXTN_MEM|IO}")
  b4e12b2d70fd9ecc ("perf: Kill __PERF_SAMPLE_CALLCHAIN_EARLY")

There is a kernel patch pending that renames PERF_MEM_LVLNUM_EXTN_MEM to
PERF_MEM_LVLNUM_CXL, tooling this time is ahead of the kernel :-)

This thus partially addresses this perf build warning:

  Warning: Kernel ABI header at 'tools/include/uapi/linux/perf_event.h' differs from latest version at 'include/uapi/linux/perf_event.h'
  diff -u tools/include/uapi/linux/perf_event.h include/uapi/linux/perf_event.h

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Link: https://lore.kernel.org/lkml/Y1k53KMdzypmU0WS@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Add autoattach optional to support one-step load-attach-pin_link.

For example,
   $ bpftool prog loadall test.o /sys/fs/bpf/test autoattach

   $ bpftool link
   26: tracing  name test1  tag f0da7d0058c00236  gpl
   	loaded_at 2022-09-09T21:39:49+0800  uid 0
   	xlated 88B  jited 55B  memlock 4096B  map_ids 3
   	btf_id 55
   28: kprobe  name test3  tag 002ef1bef0723833  gpl
   	loaded_at 2022-09-09T21:39:49+0800  uid 0
   	xlated 88B  jited 56B  memlock 4096B  map_ids 3
   	btf_id 55
   57: tracepoint  name oncpu  tag 7aa55dfbdcb78941  gpl
   	loaded_at 2022-09-09T21:41:32+0800  uid 0
   	xlated 456B  jited 265B  memlock 4096B  map_ids 17,13,14,15
   	btf_id 82

   $ bpftool link
   1: tracing  prog 26
   	prog_type tracing  attach_type trace_fentry
   3: perf_event  prog 28
   10: perf_event  prog 57

The autoattach optional can support tracepoints, k(ret)probes,
u(ret)probes.

Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/1665736275-28143-2-git-send-email-wangyufen@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add autoattach optional to prog load|loadall for supporting
one-step load-attach-pin_link.

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/1665736275-28143-3-git-send-email-wangyufen@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add autoattach optional to prog load|loadall for supporting
one-step load-attach-pin_link.

Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/1665736275-28143-4-git-send-email-wangyufen@huawei.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Commands "bpftool help" or "bpftool version" use argv[0] to display the
name of the binary. While it is a convenient way to retrieve the string,
it does not always produce the most readable output. For example,
because of the way bpftool is currently packaged on Ubuntu (using a
wrapper script), the command displays the absolute path for the binary:

    $ bpftool version | head -n 1
    /usr/lib/linux-tools/5.15.0-50-generic/bpftool v5.15.60

More generally, there is no apparent reason for keeping the whole path
and exact binary name in this output. If the user wants to understand
what binary is being called, there are other ways to do so. This commit
replaces argv[0] with "bpftool", to simply reflect what the tool is
called. This is aligned on what "ip" or "tc" do, for example.

As an additional benefit, this seems to help with integration with
Meson for packaging [0].

[0] NixOS/nixpkgs#195934

Suggested-by: Vladimír Čunát <vladimir.cunat@nic.cz>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221020100300.69328-1-quentin@isovalent.com
Along with the version number, "bpftool version" displays a list of
features that were selected at compilation time for bpftool. It would be
useful to indicate in that list whether a binary is a bootstrap version
of bpftool. Given that an increasing number of components rely on
bootstrap versions for generating skeletons, this could help understand
what a binary is capable of if it has been copied outside of the usual
"bootstrap" directory.

To detect a bootstrap version, we simply rely on the absence of
implementation for the do_prog() function. To do this, we must move the
(unchanged) list of commands before do_version(), which in turn requires
renaming this "cmds" array to avoid shadowing it with the "cmds"
argument in cmd_select().

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20221020100332.69563-1-quentin@isovalent.com
_GNU_SOURCE is defined in several source files for bpftool, but only one
of them takes the precaution of checking whether the value is already
defined. Add #ifndef for other occurrences too.

This is in preparation for the support of disassembling JIT-ed programs
with LLVM, with $(llvm-config --cflags) passing -D_GNU_SOURCE as a
compilation argument.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221025150329.97371-2-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The JIT disassembler in bpftool is the only components (with the JSON
writer) using asserts to check the return values of functions. But it
does not do so in a consistent way, and diasm_print_insn() returns no
value, although sometimes the operation failed.

Remove the asserts, and instead check the return values, print messages
on errors, and propagate the error to the caller from prog.c.

Remove the inclusion of assert.h from jit_disasm.c, and also from map.c
where it is unused.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221025150329.97371-3-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Make FEATURE_TESTS and FEATURE_DISPLAY easier to read and less likely to
be subject to conflicts on updates by having one feature per line.

Suggested-by: Andres Freund <andres@anarazel.de>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221025150329.97371-4-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Bpftool uses libbfd for disassembling JIT-ed programs. But the feature
is optional, and the tool can be compiled without libbfd support. The
Makefile sets the relevant variables accordingly. It also sets variables
related to libbfd's interface, given that it has changed over time.

Group all those libbfd-related definitions so that it's easier to
understand what we are testing for, and only use variables related to
libbfd's interface if we need libbfd in the first place.

In addition to make the Makefile clearer, grouping the definitions
related to disassembling JIT-ed programs will help support alternatives
to libbfd.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221025150329.97371-5-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Refactor disasm_print_insn() to extract the code specific to libbfd and
move it to dedicated functions. There is no functional change. This is
in preparation for supporting an alternative library for disassembling
the instructions.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20221025150329.97371-6-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
To disassemble instructions for JIT-ed programs, bpftool has relied on
the libbfd library. This has been problematic in the past: libbfd's
interface is not meant to be stable and has changed several times. For
building bpftool, we have to detect how the libbfd version on the system
behaves, which is why we have to handle features disassembler-four-args
and disassembler-init-styled in the Makefile. When it comes to shipping
bpftool, this has also caused issues with several distribution
maintainers unwilling to support the feature (see for example Debian's
page for binutils-dev, which ships libbfd: "Note that building Debian
packages which depend on the shared libbfd is Not Allowed." [0]).

For these reasons, we add support for LLVM as an alternative to libbfd
for disassembling instructions of JIT-ed programs. Thanks to the
preparation work in the previous commits, it's easy to add the library
by passing the relevant compilation options in the Makefile, and by
adding the functions for setting up the LLVM disassembler in file
jit_disasm.c.

The LLVM disassembler requires the LLVM development package (usually
llvm-dev or llvm-devel).

The expectation is that the interface for this disassembler will be more
stable. There is a note in LLVM's Developer Policy [1] stating that the
stability for the C API is "best effort" and not guaranteed, but at
least there is some effort to keep compatibility when possible (which
hasn't really been the case for libbfd so far). Furthermore, the Debian
page for the related LLVM package does not caution against linking to
the lib, as binutils-dev page does.

Naturally, the display of disassembled instructions comes with a few
minor differences. Here is a sample output with libbfd (already
supported before this patch):

    # bpftool prog dump jited id 56
    bpf_prog_6deef7357e7b4530:
       0:   nopl   0x0(%rax,%rax,1)
       5:   xchg   %ax,%ax
       7:   push   %rbp
       8:   mov    %rsp,%rbp
       b:   push   %rbx
       c:   push   %r13
       e:   push   %r14
      10:   mov    %rdi,%rbx
      13:   movzwq 0xb4(%rbx),%r13
      1b:   xor    %r14d,%r14d
      1e:   or     $0x2,%r14d
      22:   mov    $0x1,%eax
      27:   cmp    $0x2,%r14
      2b:   jne    0x000000000000002f
      2d:   xor    %eax,%eax
      2f:   pop    %r14
      31:   pop    %r13
      33:   pop    %rbx
      34:   leave
      35:   ret

LLVM supports several variants that we could set when initialising the
disassembler, for example with:

    LLVMSetDisasmOptions(*ctx,
                         LLVMDisassembler_Option_AsmPrinterVariant);

but the default printer is used for now. Here is the output with LLVM:

    # bpftool prog dump jited id 56
    bpf_prog_6deef7357e7b4530:
       0:   nopl    (%rax,%rax)
       5:   nop
       7:   pushq   %rbp
       8:   movq    %rsp, %rbp
       b:   pushq   %rbx
       c:   pushq   %r13
       e:   pushq   %r14
      10:   movq    %rdi, %rbx
      13:   movzwq  180(%rbx), %r13
      1b:   xorl    %r14d, %r14d
      1e:   orl     $2, %r14d
      22:   movl    $1, %eax
      27:   cmpq    $2, %r14
      2b:   jne     0x2f
      2d:   xorl    %eax, %eax
      2f:   popq    %r14
      31:   popq    %r13
      33:   popq    %rbx
      34:   leave
      35:   retq

The LLVM disassembler comes as the default choice, with libbfd as a
fall-back.

Of course, we could replace libbfd entirely and avoid supporting two
different libraries. One reason for keeping libbfd is that, right now,
it works well, we have all we need in terms of features detection in the
Makefile, so it provides a fallback for disassembling JIT-ed programs if
libbfd is installed but LLVM is not. The other motivation is that libbfd
supports nfp instruction for Netronome's SmartNICs and can be used to
disassemble offloaded programs, something that LLVM cannot do. If
libbfd's interface breaks again in the future, we might reconsider
keeping support for it.

[0] https://packages.debian.org/buster/binutils-dev
[1] https://llvm.org/docs/DeveloperPolicy.html#c-api-changes

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221025150329.97371-7-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
For offloaded BPF programs, instead of failing to create the
LLVM disassembler without even looking for a triple at all, do run the
function that attempts to retrieve a valid architecture name for the
device.

It will still fail for the LLVM disassembler, because currently we have
no valid triple to return (NFP disassembly is not supported by LLVM).
But failing in that function is more logical than to assume in
jit_disasm.c that passing an "arch" name is simply not supported.

Suggested-by: Song Liu <song@kernel.org>
Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20221025150329.97371-8-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Similarly to "libbfd", add a "llvm" feature to the output of command
"bpftool version" to indicate that LLVM is used for disassembling JIT-ed
programs. This feature is mutually exclusive (from Makefile definitions)
with "libbfd".

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Tested-by: Niklas Söderlund <niklas.soderlund@corigine.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221025150329.97371-9-quentin@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Similar to sk/inode/task storage, implement similar cgroup local storage.

There already exists a local storage implementation for cgroup-attached
bpf programs.  See map type BPF_MAP_TYPE_CGROUP_STORAGE and helper
bpf_get_local_storage(). But there are use cases such that non-cgroup
attached bpf progs wants to access cgroup local storage data. For example,
tc egress prog has access to sk and cgroup. It is possible to use
sk local storage to emulate cgroup local storage by storing data in socket.
But this is a waste as it could be lots of sockets belonging to a particular
cgroup. Alternatively, a separate map can be created with cgroup id as the key.
But this will introduce additional overhead to manipulate the new map.
A cgroup local storage, similar to existing sk/inode/task storage,
should help for this use case.

The life-cycle of storage is managed with the life-cycle of the
cgroup struct.  i.e. the storage is destroyed along with the owning cgroup
with a call to bpf_cgrp_storage_free() when cgroup itself
is deleted.

The userspace map operations can be done by using a cgroup fd as a key
passed to the lookup, update and delete operations.

Typically, the following code is used to get the current cgroup:
    struct task_struct *task = bpf_get_current_task_btf();
    ... task->cgroups->dfl_cgrp ...
and in structure task_struct definition:
    struct task_struct {
        ....
        struct css_set __rcu            *cgroups;
        ....
    }
With sleepable program, accessing task->cgroups is not protected by rcu_read_lock.
So the current implementation only supports non-sleepable program and supporting
sleepable program will be the next step together with adding rcu_read_lock
protection for rcu tagged structures.

Since map name BPF_MAP_TYPE_CGROUP_STORAGE has been used for old cgroup local
storage support, the new map name BPF_MAP_TYPE_CGRP_STORAGE is used
for cgroup storage available to non-cgroup-attached bpf programs. The old
cgroup storage supports bpf_get_local_storage() helper to get the cgroup data.
The new cgroup storage helper bpf_cgrp_storage_get() can provide similar
functionality. While old cgroup storage pre-allocates storage memory, the new
mechanism can also pre-allocate with a user space bpf_map_update_elem() call
to avoid potential run-time memory allocation failure.
Therefore, the new cgroup storage can provide all functionality w.r.t.
the old one. So in uapi bpf.h, the old BPF_MAP_TYPE_CGROUP_STORAGE is alias to
BPF_MAP_TYPE_CGROUP_STORAGE_DEPRECATED to indicate the old cgroup storage can
be deprecated since the new one can provide the same functionality.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221026042850.673791-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add support for new cgroup local storage

Acked-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20221026042901.674177-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
There is a spelling mistake in an error message. Fix it.

Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/r/20221026081645.3186878-1-colin.i.king@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
…out FILE

When using bpftool to pin {PROG, MAP, LINK} without FILE,
segmentation fault will occur. The reson is that the lack
of FILE will cause strlen to trigger NULL pointer dereference.
The corresponding stacktrace is shown below:

do_pin
  do_pin_any
    do_pin_fd
      mount_bpffs_for_pin
        strlen(name) <- NULL pointer dereference

Fix it by adding validation to the common process.

Fixes: 75a1e792c335 ("tools: bpftool: Allow all prog/map handles for pinning objects")
Signed-off-by: Pu Lehui <pulehui@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20221102084034.3342995-1-pulehui@huaweicloud.com
…lues

An update for libbpf's hashmap interface from void* -> void* to a
polymorphic one, allowing both long and void* keys and values.

This simplifies many use cases in libbpf as hashmaps there are mostly
integer to integer.

Perf copies hashmap implementation from libbpf and has to be
updated as well.

Changes to libbpf, selftests/bpf and perf are packed as a single
commit to avoid compilation issues with any future bisect.

Polymorphic interface is acheived by hiding hashmap interface
functions behind auxiliary macros that take care of necessary
type casts, for example:

    #define hashmap_cast_ptr(p)						\
	({								\
		_Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\
			       #p " pointee should be a long-sized integer or a pointer"); \
		(long *)(p);						\
	})

    bool hashmap_find(const struct hashmap *map, long key, long *value);

    #define hashmap__find(map, key, value) \
		hashmap_find((map), (long)(key), hashmap_cast_ptr(value))

- hashmap__find macro casts key and value parameters to long
  and long* respectively
- hashmap_cast_ptr ensures that value pointer points to a memory
  of appropriate size.

This hack was suggested by Andrii Nakryiko in [1].
This is a follow up for [2].

[1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/
[2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d

Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com
The bpf-tc prog has already been able to access the
skb_hwtstamps(skb)->hwtstamp.  This patch extends the same hwtstamp
access to the sockops prog.

In sockops, the skb is also available to the bpf prog during
the BPF_SOCK_OPS_PARSE_HDR_OPT_CB event.  There is a use case
that the hwtstamp will be useful to the sockops prog to better
measure the one-way-delay when the sender has put the tx
timestamp in the tcp header option.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20221107230420.4192307-2-martin.lau@linux.dev
@qmonnet qmonnet force-pushed the bpftool-sync-2022-11-16T14-33-28.872Z branch 4 times, most recently from 3c86c62 to c2bdb99 Compare November 17, 2022 17:22
With the recent switch to LLVM as the default library for disassembling
JIT-compiled programs [0], we need to add a probe to check the
availability of the LLVM disassembler (part of the LLVM library). We
also need to define $(LLVM_CONFIG) for the probe and build to work.

The LLVM library is packaged for many distributions, usually as llvm-dev
or llvm-devel.

[0]: Upstream commit eb9d1acf634b ("bpftool: Add LLVM as default library
    for disassembling JIT-ed programs")

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
To help understand what's going wrong when a CI run fails, build with
the verbose flag.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
@qmonnet qmonnet force-pushed the bpftool-sync-2022-11-16T14-33-28.872Z branch 18 times, most recently from e8ead45 to 949ae29 Compare November 17, 2022 22:31
We use an environment variable in the description of the CI workflow to
avoid repeating OS-based requirements for the expected features that the
bpftool binary should have. We add ".skeletons" for 22.04, but the way
we would do it would only update the variable at the current step, and
the updated value would not be passed down to the following steps. We
can pass it by writing the assignment to $GITHUB_ENV.

Let's fix it. Note that we now look for .skeletons for Ubuntu 20.04 too,
which seems to work fine.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
@qmonnet qmonnet force-pushed the bpftool-sync-2022-11-16T14-33-28.872Z branch from 3cd995b to 94e2a90 Compare November 17, 2022 23:03
Now that bpftool defaults to the LLVM library to disassemble
JIT-compiled programs, update the CI workflow to make sure we test that
case properly. First build with llvm-dev and check we default to LLVM,
then remove the library and check we fallback to libbfd.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
@qmonnet
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qmonnet commented Nov 21, 2022

Closing in favour of #49

@qmonnet qmonnet closed this Nov 21, 2022
@qmonnet qmonnet deleted the bpftool-sync-2022-11-16T14-33-28.872Z branch November 21, 2022 21:23
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6 participants