linux-dev/tools/build, branch master

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

2022-10-25T20:40:48Z

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

2022-10-04T11:55:19Z

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

2022-10-04T11:55:19Z

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

2022-10-04T11:55:19Z

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: Switch to new openssl API for test-libcrypto

2022-08-10T13:44:02Z

Switch to new EVP API for detecting libcrypto, as Fedora 36 returns an error when it encounters the deprecated function MD5_Init() and the others. The error would be interpreted as missing libcrypto, while in reality it is not. Fixes: 6e8ccb4f624a73c5 ("tools/bpf: properly account for libbfd variations") Signed-off-by: Roberto Sassu Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: bpf@vger.kernel.org Cc: Daniel Borkmann Cc: Ingo Molnar Cc: John Fastabend Cc: KP Singh Cc: llvm@lists.linux.dev Cc: Martin KaFai Lau Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Nick Terrell Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Song Liu Cc: Stanislav Fomichev Link: https://lore.kernel.org/r/20220719170555.2576993-4-roberto.sassu@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

Revert "perf build: Suppress openssl v3 deprecation warnings in libcrypto feature test"

2022-08-10T13:44:02Z

This reverts commit 10fef869a58e37ec649b61eddab545f2da57a79b. Because a proper fix was submitted. Signed-off-by: Arnaldo Carvalho de Melo

tools, build: Retry detection of bfd-related features

2022-08-10T13:44:01Z

While separate features have been defined to determine which linking flags are required to use libbfd depending on the distribution (libbfd, libbfd-liberty and libbfd-liberty-z), the same has not been done for other features requiring linking to libbfd. For example, disassembler-four-args requires linking to libbfd too, but it should use the right linking flags. If not all the required ones are specified, e.g. -liberty, detection will always fail even if the feature is available. Instead of creating new features, similarly to libbfd, simply retry detection with the different set of flags until detection succeeds (or fails, if the libraries are missing). In this way, feature detection is transparent for the users of this building mechanism (e.g. perf), and those users don't have for example to set an appropriate value for the FEATURE_CHECK_LDFLAGS-disassembler-four-args variable. The number of retries and features for which the retry mechanism is implemented is low enough to make the increase in the complexity of Makefile negligible. Tested with perf and bpftool on Ubuntu 20.04.4 LTS, Fedora 36 and openSUSE Tumbleweed. Committer notes: Do the retry for disassembler-init-styled as well. Signed-off-by: Roberto Sassu Cc: Alexei Starovoitov Cc: Andres Freund Cc: Andrii Nakryiko Cc: Daniel Borkmann Cc: Ingo Molnar Cc: John Fastabend Cc: KP Singh Cc: Martin KaFai Lau Cc: Nathan Chancellor Cc: Nick Desaulniers Cc: Nick Terrell Cc: Peter Zijlstra Cc: Quentin Monnet Cc: Song Liu Cc: Stanislav Fomichev Cc: bpf@vger.kernel.org Cc: llvm@lists.linux.dev Link: https://lore.kernel.org/r/20220719170555.2576993-1-roberto.sassu@huawei.com Signed-off-by: Arnaldo Carvalho de Melo

perf build: Suppress openssl v3 deprecation warnings in libcrypto feature test

2022-08-02T19:32:28Z

With OpenSSL v3 installed, the libcrypto feature check fails as it use the deprecated MD5_* API (and is compiled with -Werror). The error message is as follows. $ make tools/perf ``` Makefile.config:778: No libcrypto.h found, disables jitted code injection, please install openssl-devel or libssl-dev Auto-detecting system features: ... dwarf: [ on ] ... dwarf_getlocations: [ on ] ... glibc: [ on ] ... libbfd: [ on ] ... libbfd-buildid: [ on ] ... libcap: [ on ] ... libelf: [ on ] ... libnuma: [ on ] ... numa_num_possible_cpus: [ on ] ... libperl: [ on ] ... libpython: [ on ] ... libcrypto: [ OFF ] ... libunwind: [ on ] ... libdw-dwarf-unwind: [ on ] ... zlib: [ on ] ... lzma: [ on ] ... get_cpuid: [ on ] ... bpf: [ on ] ... libaio: [ on ] ... libzstd: [ on ] ... disassembler-four-args: [ on ] ``` This is very confusing because the suggested library (on my Ubuntu 20.04 it is libssl-dev) is already installed. As the test only checks for the presence of libcrypto, this commit suppresses the deprecation warning to allow the test to pass. Signed-off-by: Zixuan Tan Cc: Alexei Starovoitov Cc: Andrii Nakryiko Cc: Daniel Borkmann Cc: John Fastabend Cc: KP Singh Cc: Martin KaFai Lau Cc: Nick Terrell Cc: Song Liu Cc: Yonghong Song Cc: bpf@vger.kernel.org Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20220625153439.513559-1-tanzixuan.me@gmail.com Signed-off-by: Arnaldo Carvalho de Melo

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

2022-08-01T18:29:28Z

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

2022-08-01T18:29:10Z

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