linux.git/tools/build/feature/Makefile, branch v6.5

perf build: Fix broken feature check for libtracefs due to external lib changes

2023-07-11T16:17:05+00:00

The perf build process auto-detects features and packages already
installed for its build. This is done in directory tools/build/feature.
This directory contains small sample programs. When they successfully
compile the necessary prereqs in form of libraries and header files are
present.

Such a check is also done for libtracefs. And this check fails:

Output before:
 # rm -f test-libtracefs.bin; make test-libtracefs.bin
 gcc  -MD -Wall -Werror -o test-libtracefs.bin test-libtracefs.c \
	 > test-libtracefs.make.output 2>&1 -ltracefs
 make: *** [Makefile:211: test-libtracefs.bin] Error 1
 # cat test-libtracefs.make.output
 In file included from test-libtracefs.c:2:
 /usr/include/tracefs/tracefs.h:11:10: fatal error: \
	 event-parse.h: No such file or directory
   11 | #include 
      |          ^~~~~~~~~~~~~~~
 compilation terminated.
 #

The root cause of this compile error is commit 880885d9c22e
("libtracefs: Remove "traceevent/" from referencing libtraceevent
headers") in the libtracefs project hosted here:
https://git.kernel.org/pub/scm/libs/libtrace/libtracefs.git/

That mentioned patch removes the traceevent/ directory name from
the include statement, causing the file not to be included even
when the libtraceevent-devel package is installed. This package contains
the file referred to in tracefs/tracefs.h:

 # rpm -ql libtraceevent-devel
 /usr/include/traceevent
 /usr/include/traceevent/event-parse.h  <----- here
 /usr/include/traceevent/event-utils.h
 /usr/include/traceevent/kbuffer.h
 /usr/include/traceevent/trace-seq.h
 /usr/lib64/libtraceevent.so
 /usr/lib64/pkgconfig/libtraceevent.pc
 #

With this patch the compile succeeds.

Output after:
 # rm -f test-libtracefs.bin; make test-libtracefs.bin
 gcc  -MD -Wall -Werror -o test-libtracefs.bin test-libtracefs.c \
	 > test-libtracefs.make.output 2>&1 -I/usr/include/traceevent -ltracefs
 #

Committer testing:

  $ make -k BUILD_BPF_SKEL=1 CORESIGHT=1 O=/tmp/build/perf-tools -C tools/perf install-bin

Before:

  $ cat /tmp/build/perf-tools/feature/test-libtracefs.make.output
  In file included from test-libtracefs.c:2:
  /usr/include/tracefs/tracefs.h:11:10: fatal error: event-parse.h: No such file or directory
     11 | #include 
        |          ^~~~~~~~~~~~~~~
  compilation terminated.
  $
  $ grep -i tracefs /tmp/build/perf-tools/FEATURE-DUMP
  feature-libtracefs=0
  $

After:

  $ cat /tmp/build/perf-tools/feature/test-libtracefs.make.output
  $
  $ grep -i tracefs /tmp/build/perf-tools/FEATURE-DUMP
  feature-libtracefs=1
  $

Signed-off-by: Thomas Richter 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Heiko Carstens 
Cc: Jiri Olsa 
Cc: Steven Rostedt (VMware) 
Cc: Sumanth Korikkar 
Cc: Sven Schnelle 
Cc: Vasily Gorbik 
Link: https://lore.kernel.org/r/20230711135338.397473-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo

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 build: Remove libbpf pre-1.0 feature tests

2023-03-14T11:29:45+00:00

The feature tests were necessary for libbpf pre-1.0, but as the libbpf
implies at least 1.0 we can remove these now.

Committer notes:

Modified tools/perf/Makefile.config to better reflect the reason for
failure when the libbpf present is < 1.0 and LIBBPF_DYNAMIC=1 was asked
for.

Signed-off-by: Ian Rogers 
Acked-by: Jiri Olsa 
Tested-by: Jiri Olsa 
Cc: Adrian Hunter 
Cc: Alexander Shishkin 
Cc: Andres Freund 
Cc: Andrii Nakryiko 
Cc: Christy Lee 
Cc: Ingo Molnar 
Cc: Mark Rutland 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Quentin Monnet 
Cc: Roberto Sassu 
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230116010115.490713-2-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: Retry detection of bfd-related features

2022-08-10T13:44:01+00:00

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

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 btfraw_data() to handle older libbpf versions

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

By adding a feature test for btf__raw_data() 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-btf__raw_data.make.output
  test-libbpf-btf__raw_data.c: In function ‘main’:
  test-libbpf-btf__raw_data.c:6:9: error: implicit declaration of function ‘btf__raw_data’; did you mean ‘btf__get_raw_data’? [-Werror=implicit-function-declaration]
      6 |         btf__raw_data(NULL /* btf_ro */, NULL /* size */);
        |         ^~~~~~~~~~~~~
        |         btf__get_raw_data
  cc1: all warnings being treated as errors
  $ objdump -dS /tmp/build/perf/perf | grep ':' -A20
  00000000005b3050 :
  {
    5b3050:	55                   	push   %rbp
    5b3051:	48 89 e5             	mov    %rsp,%rbp
    5b3054:	48 83 ec 10          	sub    $0x10,%rsp
    5b3058:	64 48 8b 04 25 28 00 	mov    %fs:0x28,%rax
    5b305f:	00 00
    5b3061:	48 89 45 f8          	mov    %rax,-0x8(%rbp)
    5b3065:	31 c0                	xor    %eax,%eax
	  return btf__get_raw_data(btf_ro, size);
    5b3067:	48 8b 45 f8          	mov    -0x8(%rbp),%rax
    5b306b:	64 48 2b 04 25 28 00 	sub    %fs:0x28,%rax
    5b3072:	00 00
    5b3074:	75 06                	jne    5b307c 
  }
    5b3076:	c9                   	leave
	  return btf__get_raw_data(btf_ro, size);
    5b3077:	e9 14 99 e5 ff       	jmp    40c990 
    5b307c:	e8 af a7 e5 ff       	call   40d830 <__stack_chk_fail@plt>
    5b3081:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
    5b3088:	00 00 00 00
    $

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

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