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2024-05-07bpftool, selftests/hid/bpf: Fix 29 clang warningsJohn Hubbard1-1/+1
When building either tools/bpf/bpftool, or tools/testing/selftests/hid, (the same Makefile is used for these), clang generates many instances of the following: "clang: warning: -lLLVM-17: 'linker' input unused" Quentin points out that the LLVM version is only required in $(LIBS), not in $(CFLAGS), so the fix is to remove it from CFLAGS. Suggested-by: Quentin Monnet <qmo@kernel.org> Signed-off-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <qmo@kernel.org> Link: https://lore.kernel.org/bpf/20240505230054.13813-1-jhubbard@nvidia.com
2024-03-21bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftoolQuentin Monnet1-4/+5
Bpftool's Makefile uses $(HOST_CFLAGS) to build the bootstrap version of bpftool, in order to pick the flags for the host (where we run the bootstrap version) and not for the target system (where we plan to run the full bpftool binary). But we pass too much information through this variable. In particular, we set HOST_CFLAGS by copying most of the $(CFLAGS); but we do this after the feature detection for bpftool, which means that $(CFLAGS), hence $(HOST_CFLAGS), contain all macro definitions for using the different optional features. For example, -DHAVE_LLVM_SUPPORT may be passed to the $(HOST_CFLAGS), even though the LLVM disassembler is not used in the bootstrap version, and the related library may even be missing for the host architecture. A similar thing happens with the $(LDFLAGS), that we use unchanged for linking the bootstrap version even though they may contains flags to link against additional libraries. To address the $(HOST_CFLAGS) issue, we move the definition of $(HOST_CFLAGS) earlier in the Makefile, before the $(CFLAGS) update resulting from the feature probing - none of which being relevant to the bootstrap version. To clean up the $(LDFLAGS) for the bootstrap version, we introduce a dedicated $(HOST_LDFLAGS) variable that we base on $(LDFLAGS), before the feature probing as well. On my setup, the following macro and libraries are removed from the compiler invocation to build bpftool after this patch: -DUSE_LIBCAP -DHAVE_LLVM_SUPPORT -I/usr/lib/llvm-17/include -D_GNU_SOURCE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -lLLVM-17 -L/usr/lib/llvm-17/lib Another advantage of cleaning up these flags is that displaying available features with "bpftool version" becomes more accurate for the bootstrap bpftool, and no longer reflects the features detected (and available only) for the final binary. Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Quentin Monnet <qmo@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> Message-ID: <20240320014103.45641-1-qmo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2024-03-20bpftool: Remove unnecessary source files from bootstrap versionQuentin Monnet1-4/+1
Commit d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") added new files to the list of objects to compile in order to build the bootstrap version of bpftool. As far as I can tell, these objects are unnecessary and were added by mistake; maybe a draft version intended to add support for loading loader programs from the bootstrap version. Anyway, we can remove these object files from the list to make the bootstrap bpftool binary a tad smaller and faster to build. Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") Signed-off-by: Quentin Monnet <qmo@kernel.org> Message-ID: <20240320013457.44808-1-qmo@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-06-29bpf: Replace deprecated -target with --target= for ClangFangrui Song1-1/+1
The -target option has been deprecated since clang 3.4 in 2013. Therefore, use the preferred --target=bpf form instead. This also matches how we use --target= in scripts/Makefile.clang. Signed-off-by: Fangrui Song <maskray@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277 Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com
2023-01-13bpftool: Always disable stack protection for BPF objectsHolger Hoffstätte1-1/+2
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
2023-01-11bpftool: Add missing quotes to libbpf bootstrap submake varsJames Hilliard1-1/+1
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
2023-01-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski1-0/+4
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-12-22bpftool: Fix linkage with statically built libllvmAnton Protopopov1-0/+4
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
2022-12-21bpf: makefiles: Do not generate empty vmlinux.hChangbin Du1-0/+3
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
2022-10-25bpftool: Add LLVM as default library for disassembling JIT-ed programsQuentin Monnet1-18/+30
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>
2022-10-25bpftool: Group libbfd defs in Makefile, only pass them if we use libbfdQuentin Monnet1-12/+15
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>
2022-10-25bpftool: Split FEATURE_TESTS/FEATURE_DISPLAY definitions in MakefileQuentin Monnet1-5/+14
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>
2022-08-10bpftool: Complete libbfd feature detectionRoberto Sassu1-2/+4
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>
2022-08-06Merge tag 'perf-tools-for-v6.0-2022-08-04' of ↵Linus Torvalds1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux 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 ...
2022-08-01tools bpftool: Don't display disassembler-four-args feature testAndres Freund1-2/+1
The feature check does not seem important enough to display. Requested-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Andres Freund <andres@anarazel.de> Acked-by: Quentin Monnet <quentin@isovalent.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Ben Hutchings <benh@debian.org> Cc: Quentin Monnet <quentin@isovalent.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de Link: https://lore.kernel.org/r/20220801013834.156015-9-andres@anarazel.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-08-01tools bpftool: Fix compilation error with new binutilsAndres Freund1-1/+4
binutils changed the signature of init_disassemble_info(), which now causes compilation to fail for tools/bpf/bpftool/jit_disasm.c, e.g. on debian unstable. Relevant binutils commit: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=60a3da00bd5407f07 Wire up the feature test and switch to init_disassemble_info_compat(), which were introduced in prior commits, fixing the compilation failure. I verified that bpftool can still disassemble bpf programs, both with an old and new dis-asm.h API. There are no output changes for plain and json formats. When comparing the output from old binutils (2.35) to new bintuils with the patch (upstream snapshot) there are a few output differences, but they are unrelated to this patch. An example hunk is: 2f: pop %r14 31: pop %r13 33: pop %rbx - 34: leaveq - 35: retq + 34: leave + 35: ret Signed-off-by: Andres Freund <andres@anarazel.de> Acked-by: Quentin Monnet <quentin@isovalent.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Ben Hutchings <benh@debian.org> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Quentin Monnet <quentin@isovalent.com> Cc: Sedat Dilek <sedat.dilek@gmail.com> Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de Link: https://lore.kernel.org/r/20220801013834.156015-8-andres@anarazel.de Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-07-06bpftool: Remove zlib feature test from MakefileQuentin Monnet1-9/+2
The feature test to detect the availability of zlib in bpftool's Makefile does not bring much. The library is not optional: it may or may not be required along libbfd for disassembling instructions, but in any case it is necessary to build feature.o or even libbpf, on which bpftool depends. If we remove the feature test, we lose the nicely formatted error message, but we get a compiler error about "zlib.h: No such file or directory", which is equally informative. Let's get rid of the test. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220705200456.285943-1-quentin@isovalent.com
2022-06-09bpftool: Fix bootstrapping during a cross compilationShahab Vahedi1-1/+1
This change adjusts the Makefile to use "HOSTAR" as the archive tool to keep the sanity of the build process for the bootstrap part in check. For the rationale, please continue reading. When cross compiling bpftool with buildroot, it leads to an invocation like: $ AR="/path/to/buildroot/host/bin/arc-linux-gcc-ar" \ CC="/path/to/buildroot/host/bin/arc-linux-gcc" \ ... make Which in return fails while building the bootstrap section: ----------------------------------8<---------------------------------- make: Entering directory '/src/bpftool-v6.7.0/src' ... libbfd: [ on ] ... disassembler-four-args: [ on ] ... zlib: [ on ] ... libcap: [ OFF ] ... clang-bpf-co-re: [ on ] <-- triggers bootstrap . . . LINK /src/bpftool-v6.7.0/src/bootstrap/bpftool /usr/bin/ld: /src/bpftool-v6.7.0/src/bootstrap/libbpf/libbpf.a: error adding symbols: archive has no index; run ranlib to add one collect2: error: ld returned 1 exit status make: *** [Makefile:211: /src/bpftool-v6.7.0/src/bootstrap/bpftool] Error 1 make: *** Waiting for unfinished jobs.... AR /src/bpftool-v6.7.0/src/libbpf/libbpf.a make[1]: Leaving directory '/src/bpftool-v6.7.0/libbpf/src' make: Leaving directory '/src/bpftool-v6.7.0/src' ---------------------------------->8---------------------------------- This occurs because setting "AR" confuses the build process for the bootstrap section and it calls "arc-linux-gcc-ar" to create and index "libbpf.a" instead of the host "ar". Signed-off-by: Shahab Vahedi <shahab@synopsys.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Cc: Jean-Philippe Brucker <jean-philippe@linaro.org> Link: https://lore.kernel.org/bpf/8d297f0c-cfd0-ef6f-3970-6dddb3d9a87a@synopsys.com
2022-03-31Merge tag 'kbuild-v5.18-v2' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add new environment variables, USERCFLAGS and USERLDFLAGS to allow additional flags to be passed to user-space programs. - Fix missing fflush() bugs in Kconfig and fixdep - Fix a minor bug in the comment format of the .config file - Make kallsyms ignore llvm's local labels, .L* - Fix UAPI compile-test for cross-compiling with Clang - Extend the LLVM= syntax to support LLVM=<suffix> form for using a particular version of LLVm, and LLVM=<prefix> form for using custom LLVM in a particular directory path. - Clean up Makefiles * tag 'kbuild-v5.18-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kbuild: Make $(LLVM) more flexible kbuild: add --target to correctly cross-compile UAPI headers with Clang fixdep: use fflush() and ferror() to ensure successful write to files arch: syscalls: simplify uapi/kapi directory creation usr/include: replace extra-y with always-y certs: simplify empty certs creation in certs/Makefile certs: include certs/signing_key.x509 unconditionally kallsyms: ignore all local labels prefixed by '.L' kconfig: fix missing '# end of' for empty menu kconfig: add fflush() before ferror() check kbuild: replace $(if A,A,B) with $(or A,B) kbuild: Add environment variables for userprogs flags kbuild: unify cmd_copy and cmd_shipped
2022-02-28bpftool: Remove redundant slashesYuntao Wang1-7/+7
Because the OUTPUT variable ends with a slash but CURDIR doesn't, to keep the _OUTPUT value consistent, we add a trailing slash to CURDIR when defining _OUTPUT variable. Since the _OUTPUT variable holds a value ending with a trailing slash, there is no need to add another one when defining BOOTSTRAP_OUTPUT and LIBBPF_OUTPUT variables. Likewise, when defining LIBBPF_INCLUDE and LIBBPF_BOOTSTRAP_INCLUDE, we shouldn't add an extra slash either for the same reason. When building libbpf, the value of the DESTDIR argument should also not end with a trailing slash. Signed-off-by: Yuntao Wang <ytcoode@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20220226163815.520133-1-ytcoode@gmail.com
2022-02-24bpftool: Remove usage of reallocarray()Mauricio Vásquez1-5/+1
This commit fixes a compilation error on systems with glibc < 2.26 [0]: ``` In file included from main.h:14:0, from gen.c:24: linux/tools/include/tools/libc_compat.h:11:21: error: attempt to use poisoned "reallocarray" static inline void *reallocarray(void *ptr, size_t nmemb, size_t size) ``` This happens because gen.c pulls <bpf/libbpf_internal.h>, and then <tools/libc_compat.h> (through main.h). When COMPAT_NEED_REALLOCARRAY is set, libc_compat.h defines reallocarray() which libbpf_internal.h poisons with a GCC pragma. This commit reuses libbpf_reallocarray() implemented in commit 029258d7b228 ("libbpf: Remove any use of reallocarray() in libbpf"). v1 -> v2: - reuse libbpf_reallocarray() instead of reimplementing it Fixes: a9caaba399f9 ("bpftool: Implement "gen min_core_btf" logic") Reported-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20220221125617.39610-1-mauricio@kinvolk.io [0]: https://lore.kernel.org/bpf/3bf2bd49-9f2d-a2df-5536-bc0dde70a83b@isovalent.com/
2022-02-16bpftool: Implement "gen min_core_btf" logicMauricio Vásquez1-4/+4
This commit implements the logic for the gen min_core_btf command. Specifically, it implements the following functions: - minimize_btf(): receives the path of a source and destination BTF files and a list of BPF objects. This function records the relocations for all objects and then generates the BTF file by calling btfgen_get_btf() (implemented in the following commit). - btfgen_record_obj(): loads the BTF and BTF.ext sections of the BPF objects and loops through all CO-RE relocations. It uses bpf_core_calc_relo_insn() from libbpf and passes the target spec to btfgen_record_reloc(), that calls one of the following functions depending on the relocation kind. - btfgen_record_field_relo(): uses the target specification to mark all the types that are involved in a field-based CO-RE relocation. In this case types resolved and marked recursively using btfgen_mark_type(). Only the struct and union members (and their types) involved in the relocation are marked to optimize the size of the generated BTF file. - btfgen_record_type_relo(): marks the types involved in a type-based CO-RE relocation. In this case no members for the struct and union types are marked as libbpf doesn't use them while performing this kind of relocation. Pointed types are marked as they are used by libbpf in this case. - btfgen_record_enumval_relo(): marks the whole enum type for enum-based relocations. Signed-off-by: Mauricio Vásquez <mauricio@kinvolk.io> Signed-off-by: Rafael David Tinoco <rafael.tinoco@aquasec.com> Signed-off-by: Lorenzo Fontana <lorenzo.fontana@elastic.co> Signed-off-by: Leonardo Di Donato <leonardo.didonato@elastic.co> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220215225856.671072-5-mauricio@kinvolk.io
2022-02-15kbuild: replace $(if A,A,B) with $(or A,B)Masahiro Yamada1-2/+2
$(or ...) is available since GNU Make 3.81, and useful to shorten the code in some places. Covert as follows: $(if A,A,B) --> $(or A,B) This patch also converts: $(if A, A, B) --> $(or A, B) Strictly speaking, the latter is not an equivalent conversion because GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B) expands to " A", while $(or A, B) expands to "A". Anyway, preceding spaces are not significant in the code hunks I touched. Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
2022-02-11bpftool: Update versioning scheme, align on libbpf's version numberQuentin Monnet1-4/+2
Since the notion of versions was introduced for bpftool, it has been following the version number of the kernel (using the version number corresponding to the tree in which bpftool's sources are located). The rationale was that bpftool's features are loosely tied to BPF features in the kernel, and that we could defer versioning to the kernel repository itself. But this versioning scheme is confusing today, because a bpftool binary should be able to work with both older and newer kernels, even if some of its recent features won't be available on older systems. Furthermore, if bpftool is ported to other systems in the future, keeping a Linux-based version number is not a good option. Looking at other options, we could either have a totally independent scheme for bpftool, or we could align it on libbpf's version number (with an offset on the major version number, to avoid going backwards). The latter comes with a few drawbacks: - We may want bpftool releases in-between two libbpf versions. We can always append pre-release numbers to distinguish versions, although those won't look as "official" as something with a proper release number. But at the same time, having bpftool with version numbers that look "official" hasn't really been an issue so far. - If no new feature lands in bpftool for some time, we may move from e.g. 6.7.0 to 6.8.0 when libbpf levels up and have two different versions which are in fact the same. - Following libbpf's versioning scheme sounds better than kernel's, but ultimately it doesn't make too much sense either, because even though bpftool uses the lib a lot, its behaviour is not that much conditioned by the internal evolution of the library (or by new APIs that it may not use). Having an independent versioning scheme solves the above, but at the cost of heavier maintenance. Developers will likely forget to increase the numbers when adding features or bug fixes, and we would take the risk of having to send occasional "catch-up" patches just to update the version number. Based on these considerations, this patch aligns bpftool's version number on libbpf's. This is not a perfect solution, but 1) it's certainly an improvement over the current scheme, 2) the issues raised above are all minor at the moment, and 3) we can still move to an independent scheme in the future if we realise we need it. Given that libbpf is currently at version 0.7.0, and bpftool, before this patch, was at 5.16, we use an offset of 6 for the major version, bumping bpftool to 6.7.0. Libbpf does not export its patch number; leave bpftool's patch number at 0 for now. It remains possible to manually override the version number by setting BPFTOOL_VERSION when calling make. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20220210104237.11649-3-quentin@isovalent.com
2021-12-16bpftool: Enable cross-building with clangJean-Philippe Brucker1-6/+7
Cross-building using clang requires passing the "-target" flag rather than using the CROSS_COMPILE prefix. Makefile.include transforms CROSS_COMPILE into CLANG_CROSS_FLAGS, and adds that to CFLAGS. Remove the cross flags for the bootstrap bpftool, and erase the CROSS_COMPILE flag for the bootstrap libbpf. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20211216163842.829836-5-jean-philippe@linaro.org
2021-11-15Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski1-10/+9
Daniel Borkmann says: ==================== pull-request: bpf-next 2021-11-15 We've added 72 non-merge commits during the last 13 day(s) which contain a total of 171 files changed, 2728 insertions(+), 1143 deletions(-). The main changes are: 1) Add btf_type_tag attributes to bring kernel annotations like __user/__rcu to BTF such that BPF verifier will be able to detect misuse, from Yonghong Song. 2) Big batch of libbpf improvements including various fixes, future proofing APIs, and adding a unified, OPTS-based bpf_prog_load() low-level API, from Andrii Nakryiko. 3) Add ingress_ifindex to BPF_SK_LOOKUP program type for selectively applying the programmable socket lookup logic to packets from a given netdev, from Mark Pashmfouroush. 4) Remove the 128M upper JIT limit for BPF programs on arm64 and add selftest to ensure exception handling still works, from Russell King and Alan Maguire. 5) Add a new bpf_find_vma() helper for tracing to map an address to the backing file such as shared library, from Song Liu. 6) Batch of various misc fixes to bpftool, fixing a memory leak in BPF program dump, updating documentation and bash-completion among others, from Quentin Monnet. 7) Deprecate libbpf bpf_program__get_prog_info_linear() API and migrate its users as the API is heavily tailored around perf and is non-generic, from Dave Marchevsky. 8) Enable libbpf's strict mode by default in bpftool and add a --legacy option as an opt-out for more relaxed BPF program requirements, from Stanislav Fomichev. 9) Fix bpftool to use libbpf_get_error() to check for errors, from Hengqi Chen. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (72 commits) bpftool: Use libbpf_get_error() to check error bpftool: Fix mixed indentation in documentation bpftool: Update the lists of names for maps and prog-attach types bpftool: Fix indent in option lists in the documentation bpftool: Remove inclusion of utilities.mak from Makefiles bpftool: Fix memory leak in prog_dump() selftests/bpf: Fix a tautological-constant-out-of-range-compare compiler warning selftests/bpf: Fix an unused-but-set-variable compiler warning bpf: Introduce btf_tracing_ids bpf: Extend BTF_ID_LIST_GLOBAL with parameter for number of IDs bpftool: Enable libbpf's strict mode by default docs/bpf: Update documentation for BTF_KIND_TYPE_TAG support selftests/bpf: Clarify llvm dependency with btf_tag selftest selftests/bpf: Add a C test for btf_type_tag selftests/bpf: Rename progs/tag.c to progs/btf_decl_tag.c selftests/bpf: Test BTF_KIND_DECL_TAG for deduplication selftests/bpf: Add BTF_KIND_TYPE_TAG unit tests selftests/bpf: Test libbpf API function btf__add_type_tag() bpftool: Support BTF_KIND_TYPE_TAG libbpf: Support BTF_KIND_TYPE_TAG ... ==================== Link: https://lore.kernel.org/r/20211115162008.25916-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-15bpftool: Remove inclusion of utilities.mak from MakefilesQuentin Monnet1-1/+0
Bpftool's Makefile, and the Makefile for its documentation, both include scripts/utilities.mak, but they use none of the items defined in this file. Remove the includes. Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211110114632.24537-3-quentin@isovalent.com
2021-11-12bpftool: Normalize compile rules to specify output file lastAndrii Nakryiko1-8/+8
When dealing with verbose Makefile output, it's extremely confusing when compiler invocation commands don't specify -o <output.o> as the last argument. Normalize bpftool's Makefile to do just that, as most other BPF-related Makefiles are already doing that. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211111053624.190580-2-andrii@kernel.org
2021-11-10bpftool: Fix SPDX tag for Makefiles and .gitignoreQuentin Monnet1-1/+1
Bpftool is dual-licensed under GPLv2 and BSD-2-Clause. In commit 907b22365115 ("tools: bpftool: dual license all files") we made sure that all its source files were indeed covered by the two licenses, and that they had the correct SPDX tags. However, bpftool's Makefile, the Makefile for its documentation, and the .gitignore file were skipped at the time (their GPL-2.0-only tag was added later). Let's update the tags. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Tobias Klauser <tklauser@distanz.ch> Acked-by: Joe Stringer <joe@cilium.io> Acked-by: Song Liu <songliubraving@fb.com> Acked-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/bpf/20211105221904.3536-1-quentin@isovalent.com
2021-11-05bpftool: Install libbpf headers for the bootstrap version, tooQuentin Monnet1-10/+22
We recently changed bpftool's Makefile to make it install libbpf's headers locally instead of pulling them from the source directory of the library. Although bpftool needs two versions of libbpf, a "regular" one and a "bootstrap" version, we would only install headers for the regular libbpf build. Given that this build always occurs before the bootstrap build when building bpftool, this is enough to ensure that the bootstrap bpftool will have access to the headers exported through the regular libbpf build. However, this did not account for the case when we only want the bootstrap version of bpftool, through the "bootstrap" target. For example, perf needs the bootstrap version only, to generate BPF skeletons. In that case, when are the headers installed? For some time, the issue has been masked, because we had a step (the installation of headers internal to libbpf) which would depend on the regular build of libbpf and hence trigger the export of the headers, just for the sake of creating a directory. But this changed with commit 8b6c46241c77 ("bpftool: Remove Makefile dep. on $(LIBBPF) for $(LIBBPF_INTERNAL_HDRS)"), where we cleaned up that stage and removed the dependency on the regular libbpf build. As a result, when we only want the bootstrap bpftool version, the regular libbpf is no longer built. The bootstrap libbpf version is built, but headers are not exported, and the bootstrap bpftool build fails because of the missing headers. To fix this, we also install the library headers for the bootstrap version of libbpf, to use them for the bootstrap bpftool and for generating the skeletons. Fixes: f012ade10b34 ("bpftool: Install libbpf headers instead of including the dir") Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Link: https://lore.kernel.org/bpf/20211105015813.6171-1-quentin@isovalent.com
2021-10-26bpftool: Switch to libbpf's hashmap for pinned paths of BPF objectsQuentin Monnet1-4/+4
In order to show pinned paths for BPF programs, maps, or links when listing them with the "-f" option, bpftool creates hash maps to store all relevant paths under the bpffs. So far, it would rely on the kernel implementation (from tools/include/linux/hashtable.h). We can make bpftool rely on libbpf's implementation instead. The motivation is to make bpftool less dependent of kernel headers, to ease the path to a potential out-of-tree mirror, like libbpf has. This commit is the first step of the conversion: the hash maps for pinned paths for programs, maps, and links are converted to libbpf's hashmap.{c,h}. Other hash maps used for the PIDs of process holding references to BPF objects are left unchanged for now. On the build side, this requires adding a dependency to a second header internal to libbpf, and making it a dependency for the bootstrap bpftool version as well. The rest of the changes are a rather straightforward conversion. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-4-quentin@isovalent.com
2021-10-26bpftool: Remove Makefile dep. on $(LIBBPF) for $(LIBBPF_INTERNAL_HDRS)Quentin Monnet1-2/+2
The dependency is only useful to make sure that the $(LIBBPF_HDRS_DIR) directory is created before we try to install locally the required libbpf internal header. Let's create this directory properly instead. This is in preparation of making $(LIBBPF_INTERNAL_HDRS) a dependency to the bootstrap bpftool version, in which case we want no dependency on $(LIBBPF). Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211023205154.6710-2-quentin@isovalent.com
2021-10-20bpftool: Remove useless #include to <perf-sys.h> from map_perf_ring.cQuentin Monnet1-2/+1
The header is no longer needed since the event_pipe implementation was updated to rely on libbpf's perf_buffer. This makes bpftool free of dependencies to perf files, and we can update the Makefile accordingly. Fixes: 9b190f185d2f ("tools/bpftool: switch map event_pipe to libbpf's perf_buffer") Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211020094826.16046-1-quentin@isovalent.com
2021-10-20bpftool: Turn check on zlib from a phony target into a conditional errorQuentin Monnet1-5/+5
One of bpftool's object files depends on zlib. To make sure we do not attempt to build that object when the library is not available, commit d66fa3c70e59 ("tools: bpftool: add feature check for zlib") introduced a feature check to detect whether zlib is present. This check comes as a rule for which the target ("zdep") is a nonexistent file (phony target), which means that the Makefile always attempts to rebuild it. It is mostly harmless. However, one side effect is that, on running again once bpftool is already built, make considers that "something" (the recipe for zdep) was executed, and does not print the usual message "make: Nothing to be done for 'all'", which is a user-friendly indicator that the build went fine. Before, with some level of debugging information: $ make --debug=m [...] Reading makefiles... Auto-detecting system features: ... libbfd: [ on ] ... disassembler-four-args: [ on ] ... zlib: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] Updating makefiles.... Updating goal targets.... File 'all' does not exist. File 'zdep' does not exist. Must remake target 'zdep'. File 'all' does not exist. Must remake target 'all'. Successfully remade target file 'all'. After the patch: $ make --debug=m [...] Auto-detecting system features: ... libbfd: [ on ] ... disassembler-four-args: [ on ] ... zlib: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] Updating makefiles.... Updating goal targets.... File 'all' does not exist. Must remake target 'all'. Successfully remade target file 'all'. make: Nothing to be done for 'all'. (Note the last line, which is not part of make's debug information.) Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20211009210341.6291-4-quentin@isovalent.com
2021-10-20bpftool: Do not FORCE-build libbpfQuentin Monnet1-2/+2
In bpftool's Makefile, libbpf has a FORCE dependency, to make sure we rebuild it in case its source files changed. Let's instead make the rebuild depend on the source files directly, through a call to the "$(wildcard ...)" function. This avoids descending into libbpf's directory if there is nothing to update. Do the same for the bootstrap libbpf version. This results in a slightly faster operation and less verbose output when running make a second time in bpftool's directory. Before: Auto-detecting system features: ... libbfd: [ on ] ... disassembler-four-args: [ on ] ... zlib: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] make[1]: Entering directory '/root/dev/linux/tools/lib/bpf' make[1]: Entering directory '/root/dev/linux/tools/lib/bpf' make[1]: Nothing to be done for 'install_headers'. make[1]: Leaving directory '/root/dev/linux/tools/lib/bpf' make[1]: Leaving directory '/root/dev/linux/tools/lib/bpf' After: Auto-detecting system features: ... libbfd: [ on ] ... disassembler-four-args: [ on ] ... zlib: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] Other ways to clean up the output could be to pass the "-s" option, or to redirect the output to >/dev/null, when calling make recursively to descend into libbpf's directory. However, this would suppress some useful output if something goes wrong during the build. A better alternative would be to pass "--no-print-directory" to the recursive make, but that would still leave us with some noise for "install_headers". Skipping the descent into libbpf's directory if no source file has changed works best, and seems the most logical option overall. Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20211009210341.6291-3-quentin@isovalent.com
2021-10-20bpftool: Fix install for libbpf's internal header(s)Quentin Monnet1-7/+7
We recently updated bpftool's Makefile to make it install the headers from libbpf, instead of pulling them directly from libbpf's directory. There is also an additional header, internal to libbpf, that needs be installed. The way that bpftool's Makefile installs that particular header is currently correct, but would break if we were to modify $(LIBBPF_INTERNAL_HDRS) to make it point to more than one header. Use a static pattern rule instead, so that the Makefile can withstand the addition of other headers to install. The objective is simply to make the Makefile more robust. It should _not_ be read as an invitation to import more internal headers from libbpf into bpftool. Fixes: f012ade10b34 ("bpftool: Install libbpf headers instead of including the dir") Reported-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: John Fastabend <john.fastabend@gmail.com> Link: https://lore.kernel.org/bpf/20211009210341.6291-2-quentin@isovalent.com
2021-10-08bpftool: Add install-bin target to install binary onlyQuentin Monnet1-2/+4
With "make install", bpftool installs its binary and its bash completion file. Usually, this is what we want. But a few components in the kernel repository (namely, BPF iterators and selftests) also install bpftool locally before using it. In such a case, bash completion is not necessary and is just a useless build artifact. Let's add an "install-bin" target to bpftool, to offer a way to install the binary only. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211007194438.34443-13-quentin@isovalent.com
2021-10-08bpftool: Install libbpf headers instead of including the dirQuentin Monnet1-12/+21
Bpftool relies on libbpf, therefore it relies on a number of headers from the library and must be linked against the library. The Makefile for bpftool exposes these objects by adding tools/lib as an include directory ("-I$(srctree)/tools/lib"). This is a working solution, but this is not the cleanest one. The risk is to involuntarily include objects that are not intended to be exposed by the libbpf. The headers needed to compile bpftool should in fact be "installed" from libbpf, with its "install_headers" Makefile target. In addition, there is one header which is internal to the library and not supposed to be used by external applications, but that bpftool uses anyway. Adjust the Makefile in order to install the header files properly before compiling bpftool. Also copy the additional internal header file (nlattr.h), but call it out explicitly. Build (and install headers) in a subdirectory under bpftool/ instead of tools/lib/bpf/. When descending from a parent Makefile, this is configurable by setting the OUTPUT, LIBBPF_OUTPUT and LIBBPF_DESTDIR variables. Also adjust the Makefile for BPF selftests, so as to reuse the (host) libbpf compiled earlier and to avoid compiling a separate version of the library just for bpftool. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211007194438.34443-4-quentin@isovalent.com
2021-09-14libbpf: Make libbpf_version.h non-auto-generatedAndrii Nakryiko1-1/+0
Turn previously auto-generated libbpf_version.h header into a normal header file. This prevents various tricky Makefile integration issues, simplifies the overall build process, but also allows to further extend it with some more versioning-related APIs in the future. To prevent accidental out-of-sync versions as defined by libbpf.map and libbpf_version.h, Makefile checks their consistency at build time. Simultaneously with this change bump libbpf.map to v0.6. Also undo adding libbpf's output directory into include path for kernel/bpf/preload, bpftool, and resolve_btfids, which is not necessary because libbpf_version.h is just a normal header like any other. Fixes: 0b46b7550560 ("libbpf: Add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecations") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210913222309.3220849-1-andrii@kernel.org
2021-09-10libbpf: Add LIBBPF_DEPRECATED_SINCE macro for scheduling API deprecationsQuentin Monnet1-0/+4
Introduce a macro LIBBPF_DEPRECATED_SINCE(major, minor, message) to prepare the deprecation of two API functions. This macro marks functions as deprecated when libbpf's version reaches the values passed as an argument. As part of this change libbpf_version.h header is added with recorded major (LIBBPF_MAJOR_VERSION) and minor (LIBBPF_MINOR_VERSION) libbpf version macros. They are now part of libbpf public API and can be relied upon by user code. libbpf_version.h is installed system-wide along other libbpf public headers. Due to this new build-time auto-generated header, in-kernel applications relying on libbpf (resolve_btfids, bpftool, bpf_preload) are updated to include libbpf's output directory as part of a list of include search paths. Better fix would be to use libbpf's make_install target to install public API headers, but that clean up is left out as a future improvement. The build changes were tested by building kernel (with KBUILD_OUTPUT and O= specified explicitly), bpftool, libbpf, selftests/bpf, and resolve_btfids builds. No problems were detected. Note that because of the constraints of the C preprocessor we have to write a few lines of macro magic for each version used to prepare deprecation (0.6 for now). Also, use LIBBPF_DEPRECATED_SINCE() to schedule deprecation of btf__get_from_id() and btf__load(), which are replaced by btf__load_from_kernel_by_id() and btf__load_into_kernel(), respectively, starting from future libbpf v0.6. This is part of libbpf 1.0 effort ([0]). [0] Closes: https://github.com/libbpf/libbpf/issues/278 Co-developed-by: Quentin Monnet <quentin@isovalent.com> Co-developed-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210908213226.1871016-1-andrii@kernel.org
2021-06-08tools/bpftool: Fix cross-buildJean-Philippe Brucker1-1/+4
When the bootstrap and final bpftool have different architectures, we need to build two distinct disasm.o objects. Add a recipe for the bootstrap disasm.o. After commit d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") cross-building bpftool didn't work anymore, because the bootstrap bpftool was linked using objects from different architectures: $ make O=/tmp/bpftool ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- -C tools/bpf/bpftool/ V=1 [...] aarch64-linux-gnu-gcc ... -c -MMD -o /tmp/bpftool/disasm.o /home/z/src/linux/kernel/bpf/disasm.c gcc ... -c -MMD -o /tmp/bpftool//bootstrap/main.o main.c gcc ... -o /tmp/bpftool//bootstrap/bpftool /tmp/bpftool//bootstrap/main.o ... /tmp/bpftool/disasm.o /usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183) /usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183) /usr/bin/ld: /tmp/bpftool/disasm.o: Relocations in generic ELF (EM: 183) /usr/bin/ld: /tmp/bpftool/disasm.o: error adding symbols: file in wrong format collect2: error: ld returned 1 exit status [...] The final bpftool was built for e.g. arm64, while the bootstrap bpftool, executed on the host, was built for x86. The problem here was that disasm.o linked into the bootstrap bpftool was arm64 rather than x86. With the fix we build two disasm.o, one for the target bpftool in arm64, and one for the bootstrap bpftool in x86. Fixes: d510296d331a ("bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210603170515.1854642-1-jean-philippe@linaro.org
2021-05-19bpftool: Use syscall/loader program in "prog load" and "gen skeleton" command.Alexei Starovoitov1-1/+1
Add -L flag to bpftool to use libbpf gen_trace facility and syscall/loader program for skeleton generation and program loading. "bpftool gen skeleton -L" command will generate a "light skeleton" or "loader skeleton" that is similar to existing skeleton, but has one major difference: $ bpftool gen skeleton lsm.o > lsm.skel.h $ bpftool gen skeleton -L lsm.o > lsm.lskel.h $ diff lsm.skel.h lsm.lskel.h @@ -5,34 +4,34 @@ #define __LSM_SKEL_H__ #include <stdlib.h> -#include <bpf/libbpf.h> +#include <bpf/bpf.h> The light skeleton does not use majority of libbpf infrastructure. It doesn't need libelf. It doesn't parse .o file. It only needs few sys_bpf wrappers. All of them are in bpf/bpf.h file. In future libbpf/bpf.c can be inlined into bpf.h, so not even libbpf.a would be needed to work with light skeleton. "bpftool prog load -L file.o" command is introduced for debugging of syscall/loader program generation. Just like the same command without -L it will try to load the programs from file.o into the kernel. It won't even try to pin them. "bpftool prog load -L -d file.o" command will provide additional debug messages on how syscall/loader program was generated. Also the execution of syscall/loader program will use bpf_trace_printk() for each step of loading BTF, creating maps, and loading programs. The user can do "cat /.../trace_pipe" for further debug. An example of fexit_sleep.lskel.h generated from progs/fexit_sleep.c: struct fexit_sleep { struct bpf_loader_ctx ctx; struct { struct bpf_map_desc bss; } maps; struct { struct bpf_prog_desc nanosleep_fentry; struct bpf_prog_desc nanosleep_fexit; } progs; struct { int nanosleep_fentry_fd; int nanosleep_fexit_fd; } links; struct fexit_sleep__bss { int pid; int fentry_cnt; int fexit_cnt; } *bss; }; Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210514003623.28033-18-alexei.starovoitov@gmail.com
2021-02-23Merge tag 'perf-tools-for-v5.12-2020-02-19' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux Pull perf tool updates from Arnaldo Carvalho de Melo: "New features: - Support instruction latency in 'perf report', with both memory latency (weight) and instruction latency information, users can locate expensive load instructions and understand time spent in different stages. - Extend 'perf c2c' to display the number of loads which were blocked by data or address conflict. - Add 'perf stat' support for L2 topdown events in systems such as Intel's Sapphire rapids server. - Add support for PERF_SAMPLE_CODE_PAGE_SIZE in various tools, as a sort key, for instance: perf report --stdio --sort=comm,symbol,code_page_size - New 'perf daemon' command to run long running sessions while providing a way to control the enablement of events without restarting a traditional 'perf record' session. - Enable counting events for BPF programs in 'perf stat' just like for other targets (tid, cgroup, cpu, etc), e.g.: # perf stat -e ref-cycles,cycles -b 254 -I 1000 1.487903822 115,200 ref-cycles 1.487903822 86,012 cycles 2.489147029 80,560 ref-cycles 2.489147029 73,784 cycles ^C The example above counts 'cycles' and 'ref-cycles' of BPF program of id 254. It is similar to bpftool-prog-profile command, but more flexible. - Support the new layout for PERF_RECORD_MMAP2 to carry the DSO build-id using infrastructure generalised from the eBPF subsystem, removing the need for traversing the perf.data file to collect build-ids at the end of 'perf record' sessions and helping with long running sessions where binaries can get replaced in updates, leading to possible mis-resolution of symbols. - Support filtering by hex address in 'perf script'. - Support DSO filter in 'perf script', like in other perf tools. - Add namespaces support to 'perf inject' - Add support for SDT (Dtrace Style Markers) events on ARM64. perf record: - Fix handling of eventfd() when draining a buffer in 'perf record'. - Improvements to the generation of metadata events for pre-existing threads (mmaps, comm, etc), speeding up the work done at the start of system wide or per CPU 'perf record' sessions. Hardware tracing: - Initial support for tracing KVM with Intel PT. - Intel PT fixes for IPC - Support Intel PT PSB (synchronization packets) events. - Automatically group aux-output events to overcome --filter syntax. - Enable PERF_SAMPLE_DATA_SRC on ARMs SPE. - Update ARM's CoreSight hardware tracing OpenCSD library to v1.0.0. perf annotate TUI: - Fix handling of 'k' ("show line number") hotkey - Fix jump parsing for C++ code. perf probe: - Add protection to avoid endless loop. cgroups: - Avoid reading cgroup mountpoint multiple times, caching it. - Fix handling of cgroup v1/v2 in mixed hierarchy. Symbol resolving: - Add OCaml symbol demangling. - Further fixes for handling PE executables when using perf with Wine and .exe/.dll files. - Fix 'perf unwind' DSO handling. - Resolve symbols against debug file first, to deal with artifacts related to LTO. - Fix gap between kernel end and module start on powerpc. Reporting tools: - The DSO filter shouldn't show samples in unresolved maps. - Improve debuginfod support in various tools. build ids: - Fix 16-byte build ids in 'perf buildid-cache', add a 'perf test' entry for that case. perf test: - Support for PERF_SAMPLE_WEIGHT_STRUCT. - Add test case for PERF_SAMPLE_CODE_PAGE_SIZE. - Shell based tests for 'perf daemon's commands ('start', 'stop, 'reconfig', 'list', etc). - ARM cs-etm 'perf test' fixes. - Add parse-metric memory bandwidth testcase. Compiler related: - Fix 'perf probe' kretprobe issue caused by gcc 11 bug when used with -fpatchable-function-entry. - Fix ARM64 build with gcc 11's -Wformat-overflow. - Fix unaligned access in sample parsing test. - Fix printf conversion specifier for IP addresses on arm64, s390 and powerpc. Arch specific: - Support exposing Performance Monitor Counter SPRs as part of extended regs on powerpc. - Add JSON 'perf stat' metrics for ARM64's imx8mp, imx8mq and imx8mn DDR, fix imx8mm ones. - Fix common and uarch events for ARM64's A76 and Ampere eMag" * tag 'perf-tools-for-v5.12-2020-02-19' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (148 commits) perf buildid-cache: Don't skip 16-byte build-ids perf buildid-cache: Add test for 16-byte build-id perf symbol: Remove redundant libbfd checks perf test: Output the sub testing result in cs-etm perf test: Suppress logs in cs-etm testing perf tools: Fix arm64 build error with gcc-11 perf intel-pt: Add documentation for tracing virtual machines perf intel-pt: Split VM-Entry and VM-Exit branches perf intel-pt: Adjust sample flags for VM-Exit perf intel-pt: Allow for a guest kernel address filter perf intel-pt: Support decoding of guest kernel perf machine: Factor out machine__idle_thread() perf machine: Factor out machines__find_guest() perf intel-pt: Amend decoder to track the NR flag perf intel-pt: Retain the last PIP packet payload as is perf intel_pt: Add vmlaunch and vmresume as branches perf script: Add branch types for VM-Entry and VM-Exit perf auxtrace: Automatically group aux-output events perf test: Fix unaligned access in sample parsing test perf tools: Support arch specific PERF_SAMPLE_WEIGHT_STRUCT processing ...
2021-01-29tools: Factor Clang, LLC and LLVM utils definitionsSedat Dilek1-2/+0
When dealing with BPF/BTF/pahole and DWARF v5 I wanted to build bpftool. While looking into the source code I found duplicate assignments in misc tools for the LLVM eco system, e.g. clang and llvm-objcopy. Move the Clang, LLC and/or LLVM utils definitions to tools/scripts/Makefile.include file and add missing includes where needed. Honestly, I was inspired by the commit c8a950d0d3b9 ("tools: Factor HOSTCC, HOSTLD, HOSTAR definitions"). I tested with bpftool and perf on Debian/testing AMD64 and LLVM/Clang v11.1.0-rc1. Build instructions: [ make and make-options ] MAKE="make V=1" MAKE_OPTS="HOSTCC=clang HOSTCXX=clang++ HOSTLD=ld.lld CC=clang LD=ld.lld LLVM=1 LLVM_IAS=1" MAKE_OPTS="$MAKE_OPTS PAHOLE=/opt/pahole/bin/pahole" [ clean-up ] $MAKE $MAKE_OPTS -C tools/ clean [ bpftool ] $MAKE $MAKE_OPTS -C tools/bpf/bpftool/ [ perf ] PYTHON=python3 $MAKE $MAKE_OPTS -C tools/perf/ I was careful with respecting the user's wish to override custom compiler, linker, GNU/binutils and/or LLVM utils settings. Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Jiri Olsa <jolsa@redhat.com> # tools/build and tools/perf Link: https://lore.kernel.org/bpf/20210128015117.20515-1-sedat.dilek@gmail.com
2021-01-15bpftool: Add Makefile target bootstrapSong Liu1-0/+2
This target is used to only build the bootstrap bpftool, which will be used to generate bpf skeletons for other tools, like perf. Signed-off-by: Song Liu <songliubraving@fb.com> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Acked-by: Namhyung Kim <namhyung@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kernel-team@fb.com Link: http://lore.kernel.org/lkml/20201228174054.907740-2-songliubraving@fb.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2021-01-14tools/bpftool: Add -Wall when building BPF programsIan Rogers1-1/+1
No additional warnings are generated by enabling this, but having it enabled will help avoid regressions. Signed-off-by: Ian Rogers <irogers@google.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20210113223609.3358812-2-irogers@google.com
2020-11-12tools/bpf: Always run the *-clean recipesJean-Philippe Brucker1-2/+2
Make $(LIBBPF)-clean and $(LIBBPF_BOOTSTRAP)-clean .PHONY targets, in case those files exist. And keep consistency within the Makefile by making the directory dependencies order-only. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201112091049.3159055-2-jean-philippe@linaro.org
2020-11-11tools/bpftool: Fix build slowdownJean-Philippe Brucker1-1/+3
Commit ba2fd563b740 ("tools/bpftool: Support passing BPFTOOL_VERSION to make") changed BPFTOOL_VERSION to a recursively expanded variable, forcing it to be recomputed on every expansion of CFLAGS and dramatically slowing down the bpftool build. Restore BPFTOOL_VERSION as a simply expanded variable, guarded by an ifeq(). Fixes: ba2fd563b740 ("tools/bpftool: Support passing BPFTOOL_VERSION to make") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201110164310.2600671-8-jean-philippe@linaro.org
2020-11-11tools/bpftool: Fix cross-buildJean-Philippe Brucker1-8/+26
The bpftool build first creates an intermediate binary, executed on the host, to generate skeletons required by the final build. When cross-building bpftool for an architecture different from the host, the intermediate binary should be built using the host compiler (gcc) and the final bpftool using the cross compiler (e.g. aarch64-linux-gnu-gcc). Generate the intermediate objects into the bootstrap/ directory using the host toolchain. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201110164310.2600671-4-jean-philippe@linaro.org
2020-11-11tools/bpftool: Force clean of out-of-tree buildJean-Philippe Brucker1-3/+5
Cleaning a partial build can fail if the output directory for libbpf wasn't created: $ make -C tools/bpf/bpftool O=/tmp/bpf clean /bin/sh: line 0: cd: /tmp/bpf/libbpf/: No such file or directory tools/scripts/Makefile.include:17: *** output directory "/tmp/bpf/libbpf/" does not exist. Stop. make: *** [Makefile:36: /tmp/bpf/libbpf/libbpf.a-clean] Error 2 As a result make never gets around to clearing the leftover objects. Add the libbpf output directory as clean dependency to ensure clean always succeeds (similarly to the "descend" macro). The directory is later removed by the clean recipe. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20201110164310.2600671-3-jean-philippe@linaro.org