kernel/linux.git/tools/build/Makefile.feature, branch v6.6.131

tools build: Add a feature test for scandirat(), that is not implemented so far in musl and uclibc

2023-04-04T16:18:17+00:00

We use it just when listing tracepoint events, and for root, so just emit a warning about it to get users to ask the library maintainers to implement it, as suggested in this systemd ticket: https://github.com/systemd/casync/issues/129 Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/lkml/ZCwv4z5Dh%2FdHUMG6@kernel.org/ Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add feature test for abi::__cxa_demangle

2023-03-14T11:29:46+00:00

cxxabi.h is part of libsdtc++ and LLVM's libcxx, providing abi::__cxa_demangle a portable C++ demangler. Add a feature test to detect that the function is available. Signed-off-by: Ian Rogers Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Andres Freund Cc: Ingo Molnar Cc: Jiri Olsa Cc: Leo Yan Cc: Mark Rutland Cc: Martin Liška Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Pavithra Gurushankar Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Roberto Sassu Cc: Stephane Eranian Cc: Tiezhu Yang Cc: Tom Rix Cc: Yang Jihong Cc: llvm@lists.linux.dev Link: https://lore.kernel.org/r/20230311065753.3012826-2-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo

perf bpf: Fix build with libbpf 0.7.0 by checking if bpf_program__set_insns() is available

2022-10-25T20:40:48+00:00

During the transition to libbpf 1.0 some functions that perf used were deprecated and finally removed from libbpf, so bpf_program__set_insns() was introduced for perf to continue to use its bpf loader. But when build with LIBBPF_DYNAMIC=1 we now need to check if that function is available so that perf can build with older libbpf versions, even if the end result is emitting a warning to the user that the use of the perf BPF loader requires a newer libbpf, since bpf_program__set_insns() touches libbpf objects internal state. This affects only 'perf trace' when using bpf C code or pre-compiled bytecode as an event. Noticed on RHEL9, that has libbpf 0.7.0, where bpf_program__set_insns() isn't available. Signed-off-by: Arnaldo Carvalho de Melo

tools build: Display logical OR of a feature flavors

2022-10-04T11:55:19+00:00

Sometimes, features are simply different flavors of another feature, to properly detect the exact dependencies needed by different Linux distributions. For example, libbfd has three flavors: libbfd if the distro does not require any additional dependency; libbfd-liberty if it requires libiberty; libbfd-liberty-z if it requires libiberty and libz. It might not be clear to the user whether a feature has been successfully detected or not, given that some of its flavors will be set to OFF, others to ON. Instead, display only the feature main flavor if not in verbose mode (VF != 1), and set it to ON if at least one of its flavors has been successfully detected (logical OR), OFF otherwise. Omit the other flavors. Accomplish that by declaring a FEATURE_GROUP_MEMBERS- variable, with the list of the other flavors as variable value. For now, do it just for libbfd. In verbose mode, of if no group is defined for a feature, show the feature detection result as before. Committer testing: Collecting the output from: $ make -C tools/bpf/bpftool/ clean $ make -C tools/bpf/bpftool/ |& grep "Auto-detecting system features" -A10 $ diff -u before after --- before 2022-08-18 10:06:40.422086966 -0300 +++ after 2022-08-18 10:07:59.202138282 -0300 @@ -1,6 +1,4 @@ Auto-detecting system features: ... libbfd: [ on ] -... libbfd-liberty: [ on ] -... libbfd-liberty-z: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] $ Signed-off-by: Roberto Sassu Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Quentin Monnet Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20220818120957.319995-3-roberto.sassu@huaweicloud.com Signed-off-by: Arnaldo Carvalho de Melo

tools build: Increment room for feature name in feature detection output

2022-10-04T11:55:19+00:00

Since now there are features with a long name, increase the room for them, so that fields are correctly aligned. Signed-off-by: Roberto Sassu Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Quentin Monnet Cc: bpf@vger.kernel.org Link: https://lore.kernel.org/r/20220818120957.319995-2-roberto.sassu@huaweicloud.com Signed-off-by: Arnaldo Carvalho de Melo

tools build: Fix feature detection output due to eval expansion

2022-10-04T11:55:19+00:00

As the first eval expansion is used only to generate Makefile statements, messages should not be displayed at this stage, as for example conditional expressions are not evaluated. It can be seen for example in the output of feature detection for bpftool, where the number of detected features does not change, despite turning on the verbose mode (VF = 1) and there are additional features to display. Fix this issue by escaping the $ before $(info) statements, to ensure that messages are printed only when the function containing them is actually executed, and not when it is expanded. In addition, move the $(info) statement out of feature_print_status, due to the fact that is called both inside and outside an eval context, and place it to the caller so that the $ can be escaped when necessary. For symmetry, move the $(info) statement also out of feature_print_text, and place it to the caller. Force the TMP variable evaluation in verbose mode, to display the features in FEATURE_TESTS that are not in FEATURE_DISPLAY. Reorder perf feature detection messages (first non-verbose, then verbose ones) by moving the call to feature_display_entries earlier, before the VF environment variable check. Also, remove the newline from that function, as perf might display additional messages. Move the newline to perf Makefile, and display another one if displaying the detection result is not deferred as in the case of bpftool. Committer testing: Collecting the output from: $ make VF=1 -C tools/bpf/bpftool/ |& grep "Auto-detecting system features" -A20 $ diff -u before after --- before 2022-08-18 09:59:55.460529231 -0300 +++ after 2022-08-18 10:01:11.182517282 -0300 @@ -4,3 +4,5 @@ ... libbfd-liberty-z: [ on ] ... libcap: [ on ] ... clang-bpf-co-re: [ on ] +... disassembler-four-args: [ on ] +... disassembler-init-styled: [ OFF ] $ Fixes: 0afc5cad387db560 ("perf build: Separate feature make support into config/Makefile.feature") Signed-off-by: Roberto Sassu Tested-by: Arnaldo Carvalho de Melo Cc: Alexander Shishkin Cc: bpf@vger.kernel.org Cc: Ingo Molnar Cc: Jiri Olsa Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Quentin Monnet Link: https://lore.kernel.org/r/20220818120957.319995-1-roberto.sassu@huaweicloud.com Signed-off-by: Arnaldo Carvalho de Melo

tools build: Don't display disassembler-four-args feature test

2022-08-01T18:29:28+00:00

The feature check does not seem important enough to display. Suggested by Jiri Olsa. Signed-off-by: Andres Freund Acked-by: Quentin Monnet Tested-by: Arnaldo Carvalho de Melo Cc: Alexei Starovoitov Cc: Ben Hutchings Cc: Jiri Olsa Cc: Quentin Monnet Cc: Sedat Dilek Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de Link: https://lore.kernel.org/r/20220801013834.156015-3-andres@anarazel.de Signed-off-by: Arnaldo Carvalho de Melo

tools build: Add feature test for init_disassemble_info API changes

2022-08-01T18:29:10+00:00

binutils changed the signature of init_disassemble_info(), which now causes compilation failures for tools/{perf,bpf}, e.g. on debian unstable. Relevant binutils commit: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=60a3da00bd5407f07 This commit adds a feature test to detect the new signature. Subsequent commits will use it to fix the build failures. Signed-off-by: Andres Freund Acked-by: Quentin Monnet Cc: Alexei Starovoitov Cc: Ben Hutchings Cc: Jiri Olsa Cc: Quentin Monnet Cc: Sedat Dilek Cc: bpf@vger.kernel.org Link: http://lore.kernel.org/lkml/20220622181918.ykrs5rsnmx3og4sv@alap3.anarazel.de Link: https://lore.kernel.org/r/20220801013834.156015-2-andres@anarazel.de Signed-off-by: Arnaldo Carvalho de Melo

perf build: Stop using __weak bpf_map_create() to handle older libbpf versions

2022-05-26T15:36:56+00:00

By adding a feature test for bpf_map_create() and providing a fallback if it isn't present in older versions of libbpf. This also fixes the build with torvalds/master at this point: $ git log --oneline -5 torvalds/master babf0bb978e3c9fc (torvalds/master) Merge tag 'xfs-5.19-for-linus' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux e375780b631a5fc2 Merge tag 'fsnotify_for_v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 8b728edc5be16179 Merge tag 'fs_for_v5.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 3f306ea2e18568f6 Merge tag 'dma-mapping-5.19-2022-05-25' of git://git.infradead.org/users/hch/dma-mapping fbe86daca0ba878b Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi $ Coping with: $ git log --oneline -2 d16495a982324f75 d16495a982324f75 libbpf: remove bpf_create_map*() APIs e2371b1632b1c61c libbpf: start 1.0 development cycle $ As the __weak function fails to build as it calls the now removed bpf_create_map() API. Testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ $ make -C tools/perf BUILD_BPF_SKEL=1 LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-bpf_map_create.make.output test-libbpf-bpf_map_create.c: In function ‘main’: test-libbpf-bpf_map_create.c:6:16: error: implicit declaration of function ‘bpf_map_create’; did you mean ‘bpf_map_freeze’? [-Werror=implicit-function-declaration] 6 | return bpf_map_create(0 /* map_type */, NULL /* map_name */, 0, /* key_size */, | ^~~~~~~~~~~~~~ | bpf_map_freeze test-libbpf-bpf_map_create.c:6:87: error: expected expression before ‘,’ token 6 | return bpf_map_create(0 /* map_type */, NULL /* map_name */, 0, /* key_size */, | ^ cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf | grep ':' -A20 000000000058b290 : { 58b290: 55 push %rbp 58b291: 48 89 e5 mov %rsp,%rbp 58b294: 48 83 ec 10 sub $0x10,%rsp 58b298: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 58b29f: 00 00 58b2a1: 48 89 45 f8 mov %rax,-0x8(%rbp) 58b2a5: 31 c0 xor %eax,%eax return bpf_create_map(map_type, key_size, value_size, max_entries, 0); 58b2a7: 48 8b 45 f8 mov -0x8(%rbp),%rax 58b2ab: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 58b2b2: 00 00 58b2b4: 75 10 jne 58b2c6 } 58b2b6: c9 leave 58b2b7: 89 d6 mov %edx,%esi 58b2b9: 89 ca mov %ecx,%edx 58b2bb: 44 89 c1 mov %r8d,%ecx return bpf_create_map(map_type, key_size, value_size, max_entries, 0); 58b2be: 45 31 c0 xor %r8d,%r8d $ Cc: Andrii Nakryiko Cc: Heiko Carstens Cc: Ian Rogers Cc: Ilya Leoshkevich Cc: Jiri Olsa Cc: Song Liu Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Thomas Richter Cc: Vasily Gorbik Link: http://lore.kernel.org/linux-perf-users/Yo+XvQNKL4K5khl2@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

perf build: Stop using __weak bpf_object__next_map() to handle older libbpf versions

2022-05-26T14:02:02+00:00

By adding a feature test for bpf_object__next_map() and providing a fallback if it isn't present in older versions of libbpf. Committer testing: $ rpm -q libbpf-devel libbpf-devel-0.4.0-2.fc35.x86_64 $ make -C tools/perf LIBBPF_DYNAMIC=1 O=/tmp/build/perf install-bin $ cat /tmp/build/perf/feature/test-libbpf-bpf_object__next_map.make.output test-libbpf-bpf_object__next_map.c: In function ‘main’: test-libbpf-bpf_object__next_map.c:6:9: error: implicit declaration of function ‘bpf_object__next_map’; did you mean ‘bpf_object__next’? [-Werror=implicit-function-declaration] 6 | bpf_object__next_map(NULL /* obj */, NULL /* prev */); | ^~~~~~~~~~~~~~~~~~~~ | bpf_object__next cc1: all warnings being treated as errors $ $ objdump -dS /tmp/build/perf/perf | grep ':' -A20 00000000005b2e00 : { 5b2e00: 55 push %rbp 5b2e01: 48 89 e5 mov %rsp,%rbp 5b2e04: 48 83 ec 10 sub $0x10,%rsp 5b2e08: 64 48 8b 04 25 28 00 mov %fs:0x28,%rax 5b2e0f: 00 00 5b2e11: 48 89 45 f8 mov %rax,-0x8(%rbp) 5b2e15: 31 c0 xor %eax,%eax return bpf_map__next(prev, obj); 5b2e17: 48 8b 45 f8 mov -0x8(%rbp),%rax 5b2e1b: 64 48 2b 04 25 28 00 sub %fs:0x28,%rax 5b2e22: 00 00 5b2e24: 75 0f jne 5b2e35 } 5b2e26: c9 leave 5b2e27: 49 89 f8 mov %rdi,%r8 5b2e2a: 48 89 f7 mov %rsi,%rdi return bpf_map__next(prev, obj); 5b2e2d: 4c 89 c6 mov %r8,%rsi 5b2e30: e9 cb b1 e5 ff jmp 40e000 $ Signed-off-by: Jiri Olsa Tested-by: Arnaldo Carvalho de Melo Cc: Heiko Carstens Cc: Ian Rogers Cc: Ilya Leoshkevich Cc: Sumanth Korikkar Cc: Sven Schnelle Cc: Thomas Richter Cc: Vasily Gorbik Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava Signed-off-by: Arnaldo Carvalho de Melo