kernel/linux.git/tools/bpf/bpftool/Makefile, branch v6.12.80

bpftool: Fix make dependencies for vmlinux.h

2024-05-18T17:46:16+00:00

With pre-generated vmlinux.h there is no dependency on neither vmlinux nor bootstrap bpftool. Define dependencies separately for both modes. This avoids needless rebuilds in some corner cases. Suggested-by: Jan Stancek Signed-off-by: Artem Savkov Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20240513112658.43691-1-asavkov@redhat.com Signed-off-by: Alexei Starovoitov

bpftool, selftests/hid/bpf: Fix 29 clang warnings

2024-05-06T21:39:36+00:00

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 Signed-off-by: John Hubbard Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20240505230054.13813-1-jhubbard@nvidia.com

bpftool: Clean up HOST_CFLAGS, HOST_LDFLAGS for bootstrap bpftool

2024-03-21T06:33:49+00:00

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 Signed-off-by: Quentin Monnet Acked-by: Jiri Olsa Message-ID: <20240320014103.45641-1-qmo@kernel.org> Signed-off-by: Alexei Starovoitov

bpftool: Remove unnecessary source files from bootstrap version

2024-03-20T06:17:55+00:00

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 Message-ID: <20240320013457.44808-1-qmo@kernel.org> Signed-off-by: Alexei Starovoitov

bpf: Replace deprecated -target with --target= for Clang

2023-06-29T13:46:17+00:00

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 Signed-off-by: Daniel Borkmann Acked-by: Yonghong Song Acked-by: Quentin Monnet Link: https://github.com/llvm/llvm-project/commit/274b6f0c87a6a1798de0a68135afc7f95def6277 Link: https://lore.kernel.org/bpf/20230624001856.1903733-1-maskray@google.com

bpftool: Always disable stack protection for BPF objects

2023-01-13T15:44:21+00:00

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 Signed-off-by: Daniel Borkmann Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/74cd9d2e-6052-312a-241e-2b514a75c92c@applied-asynchrony.com

bpftool: Add missing quotes to libbpf bootstrap submake vars

2023-01-10T22:12:47+00:00

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 Signed-off-by: Daniel Borkmann Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20230110014504.3120711-1-james.hilliard1@gmail.com

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-01-05T23:34:11+00:00

No conflicts. Signed-off-by: Jakub Kicinski

bpftool: Fix linkage with statically built libllvm

2022-12-22T19:09:43+00:00

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 Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20221222102627.1643709-1-aspsk@isovalent.com

bpf: makefiles: Do not generate empty vmlinux.h

2022-12-21T00:09:39+00:00

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 Signed-off-by: Andrii Nakryiko Acked-by: Quentin Monnet Link: https://lore.kernel.org/bpf/20221217223509.88254-3-changbin.du@gmail.com