When the clang toolchain has stack protection enabled in order to be
consistent with gcc - which just happens to be the case on Gentoo -
the bpftool build fails:
[...]
clang \
-I. \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \
-g -O2 -Wall -target bpf -c skeleton/pid_iter.bpf.c -o pid_iter.bpf.o
clang \
-I. \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/include/uapi/ \
-I/tmp/portage/dev-util/bpftool-6.0.12/work/linux-6.0/tools/bpf/bpftool/bootstrap/libbpf/include \
-g -O2 -Wall -target bpf -c skeleton/profiler.bpf.c -o profiler.bpf.o
skeleton/profiler.bpf.c:40:14: error: A call to built-in function '__stack_chk_fail' is not supported.
int BPF_PROG(fentry_XXX)
^
skeleton/profiler.bpf.c:94:14: error: A call to built-in function '__stack_chk_fail' is not supported.
int BPF_PROG(fexit_XXX)
^
2 errors generated.
[...]
Since stack-protector makes no sense for the BPF bits just unconditionally
disable it.
Bug: https://bugs.gentoo.org/890638
Signed-off-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/74cd9d2e-6052-312a-241e-2b514a75c92c@applied-asynchrony.com
When passing compiler variables like CC=$(HOSTCC) to a submake we must ensure the variable is quoted in order to handle cases where $(HOSTCC) may be multiple binaries. For example when using ccache $HOSTCC may be: "/usr/bin/ccache /usr/bin/gcc" If we pass CC without quotes like CC=$(HOSTCC) only the first "/usr/bin/ccache" part will be assigned to the CC variable which will cause an error due to dropping the "/usr/bin/gcc" part of the variable in the submake invocation. This fixes errors such as: /usr/bin/ccache: invalid option -- 'd' Signed-off-by: James Hilliard <james.hilliard1@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20230110014504.3120711-1-james.hilliard1@gmail.com
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since the commit eb9d1acf634b ("bpftool: Add LLVM as default library for
disassembling JIT-ed programs") we might link the bpftool program with the
libllvm library. This works fine when a shared libllvm library is available,
but fails if we want to link bpftool with a statically built LLVM:
[...]
/usr/bin/ld: /usr/local/lib/libLLVMSupport.a(CrashRecoveryContext.cpp.o): in function `llvm::CrashRecoveryContextCleanup::~CrashRecoveryContextCleanup()':
CrashRecoveryContext.cpp:(.text._ZN4llvm27CrashRecoveryContextCleanupD0Ev+0x17): undefined reference to `operator delete(void*, unsigned long)'
/usr/bin/ld: /usr/local/lib/libLLVMSupport.a(CrashRecoveryContext.cpp.o): in function `llvm::CrashRecoveryContext::~CrashRecoveryContext()':
CrashRecoveryContext.cpp:(.text._ZN4llvm20CrashRecoveryContextD2Ev+0xc8): undefined reference to `operator delete(void*, unsigned long)'
[...]
So in the case of static libllvm we need to explicitly link bpftool with
required libraries, namely, libstdc++ and those provided by the `llvm-config
--system-libs` command. We can distinguish between the shared and static cases
by using the `llvm-config --shared-mode` command.
Fixes: eb9d1acf634b ("bpftool: Add LLVM as default library for disassembling JIT-ed programs")
Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20221222102627.1643709-1-aspsk@isovalent.com
Remove the empty vmlinux.h if bpftool failed to dump btf info. The empty vmlinux.h can hide real error when reading output of make. This is done by adding .DELETE_ON_ERROR special target in related makefiles. Signed-off-by: Changbin Du <changbin.du@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20221217223509.88254-3-changbin.du@gmail.com
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>
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>
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>
Commit 6e8ccb4f624a7 ("tools/bpf: properly account for libbfd variations")
sets the linking flags depending on which flavor of the libbfd feature was
detected.
However, the flavors except libbfd cannot be detected, as they are not in
the feature list.
Complete the list of features to detect by adding libbfd-liberty and
libbfd-liberty-z.
Committer notes:
Adjust conflict with with:
1e1613f64cc8a09d ("tools bpftool: Don't display disassembler-four-args feature test")
600b7b26c07a070d ("tools bpftool: Fix compilation error with new binutils")
Fixes: 6e8ccb4f624a73c5 ("tools/bpf: properly account for libbfd variations")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Andres Freund <andres@anarazel.de>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: bpf@vger.kernel.org
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: llvm@lists.linux.dev
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Nick Terrell <terrelln@fb.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Monnet <quentin@isovalent.com>
Cc: Song Liu <song@kernel.org>
Cc: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20220719170555.2576993-2-roberto.sassu@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Pull perf tools updates from Arnaldo Carvalho de Melo:
- Introduce 'perf lock contention' subtool, using new lock contention
tracepoints and using BPF for in kernel aggregation and then
userspace processing using the perf tooling infrastructure for
resolving symbols, target specification, etc.
Since the new lock contention tracepoints don't provide lock names,
get up to 8 stack traces and display the first non-lock function
symbol name as a caller:
$ perf lock report -F acquired,contended,avg_wait,wait_total
Name acquired contended avg wait total wait
update_blocked_a... 40 40 3.61 us 144.45 us
kernfs_fop_open+... 5 5 3.64 us 18.18 us
_nohz_idle_balance 3 3 2.65 us 7.95 us
tick_do_update_j... 1 1 6.04 us 6.04 us
ep_scan_ready_list 1 1 3.93 us 3.93 us
Supports the usual 'perf record' + 'perf report' workflow as well as
a BCC/bpftrace like mode where you start the tool and then press
control+C to get results:
$ sudo perf lock contention -b
^C
contended total wait max wait avg wait type caller
42 192.67 us 13.64 us 4.59 us spinlock queue_work_on+0x20
23 85.54 us 10.28 us 3.72 us spinlock worker_thread+0x14a
6 13.92 us 6.51 us 2.32 us mutex kernfs_iop_permission+0x30
3 11.59 us 10.04 us 3.86 us mutex kernfs_dop_revalidate+0x3c
1 7.52 us 7.52 us 7.52 us spinlock kthread+0x115
1 7.24 us 7.24 us 7.24 us rwlock:W sys_epoll_wait+0x148
2 7.08 us 3.99 us 3.54 us spinlock delayed_work_timer_fn+0x1b
1 6.41 us 6.41 us 6.41 us spinlock idle_balance+0xa06
2 2.50 us 1.83 us 1.25 us mutex kernfs_iop_lookup+0x2f
1 1.71 us 1.71 us 1.71 us mutex kernfs_iop_getattr+0x2c
...
- Add new 'perf kwork' tool to trace time properties of kernel work
(such as softirq, and workqueue), uses eBPF skeletons to collect info
in kernel space, aggregating data that then gets processed by the
userspace tool, e.g.:
# perf kwork report
Kwork Name | Cpu | Total Runtime | Count | Max runtime | Max runtime start | Max runtime end |
----------------------------------------------------------------------------------------------------
nvme0q5:130 | 004 | 1.101 ms | 49 | 0.051 ms | 26035.056403 s | 26035.056455 s |
amdgpu:162 | 002 | 0.176 ms | 9 | 0.046 ms | 26035.268020 s | 26035.268066 s |
nvme0q24:149 | 023 | 0.161 ms | 55 | 0.009 ms | 26035.655280 s | 26035.655288 s |
nvme0q20:145 | 019 | 0.090 ms | 33 | 0.014 ms | 26035.939018 s | 26035.939032 s |
nvme0q31:156 | 030 | 0.075 ms | 21 | 0.010 ms | 26035.052237 s | 26035.052247 s |
nvme0q8:133 | 007 | 0.062 ms | 12 | 0.021 ms | 26035.416840 s | 26035.416861 s |
nvme0q6:131 | 005 | 0.054 ms | 22 | 0.010 ms | 26035.199919 s | 26035.199929 s |
nvme0q19:144 | 018 | 0.052 ms | 14 | 0.010 ms | 26035.110615 s | 26035.110625 s |
nvme0q7:132 | 006 | 0.049 ms | 13 | 0.007 ms | 26035.125180 s | 26035.125187 s |
nvme0q18:143 | 017 | 0.033 ms | 14 | 0.007 ms | 26035.169698 s | 26035.169705 s |
nvme0q17:142 | 016 | 0.013 ms | 1 | 0.013 ms | 26035.565147 s | 26035.565160 s |
enp5s0-rx-0:164 | 006 | 0.004 ms | 4 | 0.002 ms | 26035.928882 s | 26035.928884 s |
enp5s0-tx-0:166 | 008 | 0.003 ms | 3 | 0.002 ms | 26035.870923 s | 26035.870925 s |
--------------------------------------------------------------------------------------------------------
See commit log messages for more examples with extra options to limit
the events time window, etc.
- Add support for new AMD IBS (Instruction Based Sampling) features:
With the DataSrc extensions, the source of data can be decoded among:
- Local L3 or other L1/L2 in CCX.
- A peer cache in a near CCX.
- Data returned from DRAM.
- A peer cache in a far CCX.
- DRAM address map with "long latency" bit set.
- Data returned from MMIO/Config/PCI/APIC.
- Extension Memory (S-Link, GenZ, etc - identified by the CS target
and/or address map at DF's choice).
- Peer Agent Memory.
- Support hardware tracing with Intel PT on guest machines, combining
the traces with the ones in the host machine.
- Add a "-m" option to 'perf buildid-list' to show kernel and modules
build-ids, to display all of the information needed to do external
symbolization of kernel stack traces, such as those collected by
bpf_get_stackid().
- Add arch TSC frequency information to perf.data file headers.
- Handle changes in the binutils disassembler function signatures in
perf, bpftool and bpf_jit_disasm (Acked by the bpftool maintainer).
- Fix building the perf perl binding with the newest gcc in distros
such as fedora rawhide, where some new warnings were breaking the
build as perf uses -Werror.
- Add 'perf test' entry for branch stack sampling.
- Add ARM SPE system wide 'perf test' entry.
- Add user space counter reading tests to 'perf test'.
- Build with python3 by default, if available.
- Add python converter script for the vendor JSON event files.
- Update vendor JSON files for most Intel cores.
- Add vendor JSON File for Intel meteorlake.
- Add Arm Cortex-A78C and X1C JSON vendor event files.
- Add workaround to symbol address reading from ELF files without phdr,
falling back to the previoous equation.
- Convert legacy map definition to BTF-defined in the perf BPF script
test.
- Rework prologue generation code to stop using libbpf deprecated APIs.
- Add default hybrid events for 'perf stat' on x86.
- Add topdown metrics in the default 'perf stat' on the hybrid machines
(big/little cores).
- Prefer sampled CPU when exporting JSON in 'perf data convert'
- Fix ('perf stat CSV output linter') and ("Check branch stack
sampling") 'perf test' entries on s390.
* tag 'perf-tools-for-v6.0-2022-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (169 commits)
perf stat: Refactor __run_perf_stat() common code
perf lock: Print the number of lost entries for BPF
perf lock: Add --map-nr-entries option
perf lock: Introduce struct lock_contention
perf scripting python: Do not build fail on deprecation warnings
genelf: Use HAVE_LIBCRYPTO_SUPPORT, not the never defined HAVE_LIBCRYPTO
perf build: Suppress openssl v3 deprecation warnings in libcrypto feature test
perf parse-events: Break out tracepoint and printing
perf parse-events: Don't #define YY_EXTRA_TYPE
tools bpftool: Don't display disassembler-four-args feature test
tools bpftool: Fix compilation error with new binutils
tools bpf_jit_disasm: Don't display disassembler-four-args feature test
tools bpf_jit_disasm: Fix compilation error with new binutils
tools perf: Fix compilation error with new binutils
tools include: add dis-asm-compat.h to handle version differences
tools build: Don't display disassembler-four-args feature test
tools build: Add feature test for init_disassemble_info API changes
perf test: Add ARM SPE system wide test
perf tools: Rework prologue generation code
perf bpf: Convert legacy map definition to BTF-defined
...