<feed xmlns='http://www.w3.org/2005/Atom'>
<title>kernel/linux.git/tools/build/feature, branch v5.19</title>
<subtitle>Linux kernel stable tree (mirror)</subtitle>
<id>https://git.radix-linux.su/kernel/linux.git/atom?h=v5.19</id>
<link rel='self' href='https://git.radix-linux.su/kernel/linux.git/atom?h=v5.19'/>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/'/>
<updated>2022-05-26T15:36:56+00:00</updated>
<entry>
<title>perf build: Stop using __weak bpf_map_create() to handle older libbpf versions</title>
<updated>2022-05-26T15:36:56+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-05-26T14:48:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=df76e0038370d364d4b2154fa7ddbbccc29f629f'/>
<id>urn:sha1:df76e0038370d364d4b2154fa7ddbbccc29f629f</id>
<content type='text'>
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 '&lt;bpf_map_create&gt;:' -A20
  000000000058b290 &lt;bpf_map_create&gt;:
  {
    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 &lt;bpf_map_create+0x36&gt;
  }
    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 &lt;andrii@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Song Liu &lt;songliubraving@fb.com&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: http://lore.kernel.org/linux-perf-users/Yo+XvQNKL4K5khl2@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf build: Stop using __weak btf__raw_data() to handle older libbpf versions</title>
<updated>2022-05-26T14:02:02+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-05-24T11:16:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=982be4775164d4780d9c6a2f38b365f5b5bd16d4'/>
<id>urn:sha1:982be4775164d4780d9c6a2f38b365f5b5bd16d4</id>
<content type='text'>
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 '&lt;btf__raw_data&gt;:' -A20
  00000000005b3050 &lt;btf__raw_data&gt;:
  {
    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 &lt;btf__raw_data+0x2c&gt;
  }
    5b3076:	c9                   	leave
	  return btf__get_raw_data(btf_ro, size);
    5b3077:	e9 14 99 e5 ff       	jmp    40c990 &lt;btf__get_raw_data@plt&gt;
    5b307c:	e8 af a7 e5 ff       	call   40d830 &lt;__stack_chk_fail@plt&gt;
    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 &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf build: Stop using __weak bpf_object__next_map() to handle older libbpf versions</title>
<updated>2022-05-26T14:02:02+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-05-24T11:13:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=739c9180cfa487cc92e2721e224564e4672c578e'/>
<id>urn:sha1:739c9180cfa487cc92e2721e224564e4672c578e</id>
<content type='text'>
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 '&lt;bpf_object__next_map&gt;:' -A20
  00000000005b2e00 &lt;bpf_object__next_map&gt;:
  {
    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 &lt;bpf_object__next_map+0x35&gt;
  }
    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 &lt;bpf_map__next@plt&gt;
  $

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf build: Stop using __weak bpf_object__next_program() to handle older libbpf versions</title>
<updated>2022-05-26T14:02:02+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-05-24T11:09:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=8916d72554e5f06df5ba17bfabc87c7977294ba4'/>
<id>urn:sha1:8916d72554e5f06df5ba17bfabc87c7977294ba4</id>
<content type='text'>
By adding a feature test for bpf_object__next_program() 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_program.make.output
  test-libbpf-bpf_object__next_program.c: In function ‘main’:
  test-libbpf-bpf_object__next_program.c:6:9: error: implicit declaration of function ‘bpf_object__next_program’; did you mean ‘bpf_object__unpin_programs’? [-Werror=implicit-function-declaration]
      6 |         bpf_object__next_program(NULL /* obj */, NULL /* prev */);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~
        |         bpf_object__unpin_programs
  cc1: all warnings being treated as errors
  $
  $ objdump -dS /tmp/build/perf/perf | grep '&lt;bpf_object__next_program&gt;:' -A20
  00000000005b2dc0 &lt;bpf_object__next_program&gt;:
  {
    5b2dc0:	55                   	push   %rbp
    5b2dc1:	48 89 e5             	mov    %rsp,%rbp
    5b2dc4:	48 83 ec 10          	sub    $0x10,%rsp
    5b2dc8:	64 48 8b 04 25 28 00 	mov    %fs:0x28,%rax
    5b2dcf:	00 00
    5b2dd1:	48 89 45 f8          	mov    %rax,-0x8(%rbp)
    5b2dd5:	31 c0                	xor    %eax,%eax
	  return bpf_program__next(prev, obj);
    5b2dd7:	48 8b 45 f8          	mov    -0x8(%rbp),%rax
    5b2ddb:	64 48 2b 04 25 28 00 	sub    %fs:0x28,%rax
    5b2de2:	00 00
    5b2de4:	75 0f                	jne    5b2df5 &lt;bpf_object__next_program+0x35&gt;
  }
    5b2de6:	c9                   	leave
    5b2de7:	49 89 f8             	mov    %rdi,%r8
    5b2dea:	48 89 f7             	mov    %rsi,%rdi
	  return bpf_program__next(prev, obj);
    5b2ded:	4c 89 c6             	mov    %r8,%rsi
    5b2df0:	e9 3b b4 e5 ff       	jmp    40e230 &lt;bpf_program__next@plt&gt;
    $

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf build: Stop using __weak bpf_prog_load() to handle older libbpf versions</title>
<updated>2022-05-26T14:02:02+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-05-24T11:04:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=5c83eff38194ab2c69a7dc1a64a0a3683f0a3c3a'/>
<id>urn:sha1:5c83eff38194ab2c69a7dc1a64a0a3683f0a3c3a</id>
<content type='text'>
By adding a feature test for bpf_prog_load() 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_prog_load.make.output
  test-libbpf-bpf_prog_load.c: In function ‘main’:
  test-libbpf-bpf_prog_load.c:6:16: error: implicit declaration of function ‘bpf_prog_load’ [-Werror=implicit-function-declaration]
      6 |         return bpf_prog_load(0 /* prog_type */, NULL /* prog_name */,
        |                ^~~~~~~~~~~~~
  cc1: all warnings being treated as errors
  $

  $ objdump -dS /tmp/build/perf/perf | grep '&lt;bpf_prog_load&gt;:' -A20
  00000000005b2d70 &lt;bpf_prog_load&gt;:
  {
    5b2d70:	55                   	push   %rbp
    5b2d71:	48 89 ce             	mov    %rcx,%rsi
    5b2d74:	4c 89 c8             	mov    %r9,%rax
    5b2d77:	49 89 d2             	mov    %rdx,%r10
    5b2d7a:	4c 89 c2             	mov    %r8,%rdx
    5b2d7d:	48 89 e5             	mov    %rsp,%rbp
    5b2d80:	48 83 ec 18          	sub    $0x18,%rsp
    5b2d84:	64 48 8b 0c 25 28 00 	mov    %fs:0x28,%rcx
    5b2d8b:	00 00
    5b2d8d:	48 89 4d f8          	mov    %rcx,-0x8(%rbp)
    5b2d91:	31 c9                	xor    %ecx,%ecx
  	return bpf_load_program(prog_type, insns, insn_cnt, license,
    5b2d93:	41 8b 49 5c          	mov    0x5c(%r9),%ecx
    5b2d97:	51                   	push   %rcx
    5b2d98:	4d 8b 49 60          	mov    0x60(%r9),%r9
    5b2d9c:	4c 89 d1             	mov    %r10,%rcx
    5b2d9f:	44 8b 40 1c          	mov    0x1c(%rax),%r8d
    5b2da3:	e8 f8 aa e5 ff       	call   40d8a0 &lt;bpf_load_program@plt&gt;
  }
  $

Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Tested-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf build: Fix btf__load_from_kernel_by_id() feature check</title>
<updated>2022-05-26T14:02:02+00:00</updated>
<author>
<name>Jiri Olsa</name>
<email>jolsa@kernel.org</email>
</author>
<published>2022-05-24T12:06:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=73534617dfa3c4cd95fe5ffaeff5315e9ffc2de6'/>
<id>urn:sha1:73534617dfa3c4cd95fe5ffaeff5315e9ffc2de6</id>
<content type='text'>
The btf__load_from_kernel_by_id() only takes one arg, not two.

Committer notes:

I tested it just with an older libbpf, one where
btf__load_from_kernel_by_id() wasn't introduced yet.

A test with a newer dynamic libbpf would fail because the
btf__load_from_kernel_by_id() is there, but takes just one arg.

Fixes: 0ae065a5d265bc5a ("perf build: Fix check for btf__load_from_kernel_by_id() in libbpf")
Signed-off-by: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Heiko Carstens &lt;hca@linux.ibm.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Ilya Leoshkevich &lt;iii@linux.ibm.com&gt;
Cc: Sumanth Korikkar &lt;sumanthk@linux.ibm.com&gt;
Cc: Sven Schnelle &lt;svens@linux.ibm.com&gt;
Cc: Thomas Richter &lt;tmricht@linux.ibm.com&gt;
Cc: Vasily Gorbik &lt;gor@linux.ibm.com&gt;
Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>perf build: Fix check for btf__load_from_kernel_by_id() in libbpf</title>
<updated>2022-05-20T12:45:41+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-05-20T00:25:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=0ae065a5d265bc5ada13e350015458e0c5e5c351'/>
<id>urn:sha1:0ae065a5d265bc5ada13e350015458e0c5e5c351</id>
<content type='text'>
Avi Kivity reported a problem where the __weak
btf__load_from_kernel_by_id() in tools/perf/util/bpf-event.c was being
used and it called btf__get_from_id() in tools/lib/bpf/btf.c that in
turn called back to btf__load_from_kernel_by_id(), resulting in an
endless loop.

Fix this by adding a feature test to check if
btf__load_from_kernel_by_id() is available when building perf with
LIBBPF_DYNAMIC=1, and if not then provide the fallback to the old
btf__get_from_id(), that doesn't call back to btf__load_from_kernel_by_id()
since at that time it didn't exist at all.

Tested on Fedora 35 where we have libbpf-devel 0.4.0 with LIBBPF_DYNAMIC
where we don't have btf__load_from_kernel_by_id() and thus its feature
test fail, not defining HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID:

  $ cat /tmp/build/perf-urgent/feature/test-libbpf-btf__load_from_kernel_by_id.make.output
  test-libbpf-btf__load_from_kernel_by_id.c: In function ‘main’:
  test-libbpf-btf__load_from_kernel_by_id.c:6:16: error: implicit declaration of function ‘btf__load_from_kernel_by_id’ [-Werror=implicit-function-declaration]
      6 |         return btf__load_from_kernel_by_id(20151128, NULL);
        |                ^~~~~~~~~~~~~~~~~~~~~~~~~~~
  cc1: all warnings being treated as errors
  $

  $ nm /tmp/build/perf-urgent/perf | grep btf__load_from_kernel_by_id
  00000000005ba180 T btf__load_from_kernel_by_id
  $

  $ objdump --disassemble=btf__load_from_kernel_by_id -S /tmp/build/perf-urgent/perf

  /tmp/build/perf-urgent/perf:     file format elf64-x86-64
  &lt;SNIP&gt;
  00000000005ba180 &lt;btf__load_from_kernel_by_id&gt;:
  #include "record.h"
  #include "util/synthetic-events.h"

  #ifndef HAVE_LIBBPF_BTF__LOAD_FROM_KERNEL_BY_ID
  struct btf *btf__load_from_kernel_by_id(__u32 id)
  {
    5ba180:	55                   	push   %rbp
    5ba181:	48 89 e5             	mov    %rsp,%rbp
    5ba184:	48 83 ec 10          	sub    $0x10,%rsp
    5ba188:	64 48 8b 04 25 28 00 	mov    %fs:0x28,%rax
    5ba18f:	00 00
    5ba191:	48 89 45 f8          	mov    %rax,-0x8(%rbp)
    5ba195:	31 c0                	xor    %eax,%eax
         struct btf *btf;
  #pragma GCC diagnostic push
  #pragma GCC diagnostic ignored "-Wdeprecated-declarations"
         int err = btf__get_from_id(id, &amp;btf);
    5ba197:	48 8d 75 f0          	lea    -0x10(%rbp),%rsi
    5ba19b:	e8 a0 57 e5 ff       	call   40f940 &lt;btf__get_from_id@plt&gt;
    5ba1a0:	89 c2                	mov    %eax,%edx
  #pragma GCC diagnostic pop

         return err ? ERR_PTR(err) : btf;
    5ba1a2:	48 98                	cltq
    5ba1a4:	85 d2                	test   %edx,%edx
    5ba1a6:	48 0f 44 45 f0       	cmove  -0x10(%rbp),%rax
  }
  &lt;SNIP&gt;

Fixes: 218e7b775d368f38 ("perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions")
Reported-by: Avi Kivity &lt;avi@scylladb.com&gt;
Link: https://lore.kernel.org/linux-perf-users/f0add43b-3de5-20c5-22c4-70aff4af959f@scylladb.com
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Link: https://lore.kernel.org/linux-perf-users/YobjjFOblY4Xvwo7@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>tools build: Filter out options and warnings not supported by clang</title>
<updated>2022-04-09T15:34:16+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-04-05T13:33:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=41caff459a5b956b3e23ba9ca759dd0629ad3dda'/>
<id>urn:sha1:41caff459a5b956b3e23ba9ca759dd0629ad3dda</id>
<content type='text'>
These make the feature check fail when using clang, so remove them just
like is done in tools/perf/Makefile.config to build perf itself.

Adding -Wno-compound-token-split-by-macro to tools/perf/Makefile.config
when building with clang is also necessary to avoid these warnings
turned into errors (-Werror):

    CC      /tmp/build/perf/util/scripting-engines/trace-event-perl.o
  In file included from util/scripting-engines/trace-event-perl.c:35:
  In file included from /usr/lib64/perl5/CORE/perl.h:4085:
  In file included from /usr/lib64/perl5/CORE/hv.h:659:
  In file included from /usr/lib64/perl5/CORE/hv_func.h:34:
  In file included from /usr/lib64/perl5/CORE/sbox32_hash.h:4:
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: error: '(' and '{' tokens introducing statement expression appear in different macro expansion contexts [-Werror,-Wcompound-token-split-by-macro]
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:80:38: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
  #define ZAPHOD32_SCRAMBLE32(v,prime) STMT_START {  \
                                       ^~~~~~~~~~
  /usr/lib64/perl5/CORE/perl.h:737:29: note: expanded from macro 'STMT_START'
  #   define STMT_START   (void)( /* gcc supports "({ STATEMENTS; })" */
                                ^
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: note: '{' token is here
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:80:49: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
  #define ZAPHOD32_SCRAMBLE32(v,prime) STMT_START {  \
                                                  ^
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: error: '}' and ')' tokens terminating statement expression appear in different macro expansion contexts [-Werror,-Wcompound-token-split-by-macro]
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:87:41: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
      v ^= (v&gt;&gt;23);                       \
                                          ^
  /usr/lib64/perl5/CORE/zaphod32_hash.h:150:5: note: ')' token is here
      ZAPHOD32_SCRAMBLE32(state[0],0x9fade23b);
      ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
  /usr/lib64/perl5/CORE/zaphod32_hash.h:88:3: note: expanded from macro 'ZAPHOD32_SCRAMBLE32'
  } STMT_END
    ^~~~~~~~
  /usr/lib64/perl5/CORE/perl.h:738:21: note: expanded from macro 'STMT_END'
  #   define STMT_END     )
                          ^

Please refer to the discussion on the Link: tag below, where Nathan
clarifies the situation:

&lt;quote&gt;
acme&gt; And then get to the problems at the end of this message, which seem
acme&gt; similar to the problem described here:
acme&gt;
acme&gt; From  Nathan Chancellor &lt;&gt;
acme&gt; Subject	[PATCH] mwifiex: Remove unnecessary braces from HostCmd_SET_SEQ_NO_BSS_INFO
acme&gt;
acme&gt; https://lkml.org/lkml/2020/9/1/135
acme&gt;
acme&gt; So perhaps in this case its better to disable that
acme&gt; -Werror,-Wcompound-token-split-by-macro when building with clang?

Yes, I think that is probably the best solution. As far as I can tell,
at least in this file and context, the warning appears harmless, as the
"create a GNU C statement expression from two different macros" is very
much intentional, based on the presence of PERL_USE_GCC_BRACE_GROUPS.
The warning is fixed in upstream Perl by just avoiding creating GNU C
statement expressions using STMT_START and STMT_END:

  https://github.com/Perl/perl5/issues/18780
  https://github.com/Perl/perl5/pull/18984

If I am reading the source code correctly, an alternative to disabling
the warning would be specifying -DPERL_GCC_BRACE_GROUPS_FORBIDDEN but it
seems like that might end up impacting more than just this site,
according to the issue discussion above.
&lt;/quote&gt;

Based-on-a-patch-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt;
Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt; # Debian/Selfmade LLVM-14 (x86-64)
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Fangrui Song &lt;maskray@google.com&gt;
Cc: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Keeping &lt;john@metanate.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Link: http://lore.kernel.org/lkml/YkxWcYzph5pC1EK8@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>tools build: Use $(shell ) instead of `` to get embedded libperl's ccopts</title>
<updated>2022-04-09T15:33:38+00:00</updated>
<author>
<name>Arnaldo Carvalho de Melo</name>
<email>acme@redhat.com</email>
</author>
<published>2022-04-04T20:28:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=541f695cbcb6932c22638b06e0cbe1d56177e2e9'/>
<id>urn:sha1:541f695cbcb6932c22638b06e0cbe1d56177e2e9</id>
<content type='text'>
Just like its done for ldopts and for both in tools/perf/Makefile.config.

Using `` to initialize PERL_EMBED_CCOPTS somehow precludes using:

  $(filter-out SOMETHING_TO_FILTER,$(PERL_EMBED_CCOPTS))

And we need to do it to allow for building with versions of clang where
some gcc options selected by distros are not available.

Tested-by: Sedat Dilek &lt;sedat.dilek@gmail.com&gt; # Debian/Selfmade LLVM-14 (x86-64)
Cc: Adrian Hunter &lt;adrian.hunter@intel.com&gt;
Cc: Fangrui Song &lt;maskray@google.com&gt;
Cc: Florian Fainelli &lt;f.fainelli@gmail.com&gt;
Cc: Ian Rogers &lt;irogers@google.com&gt;
Cc: Jiri Olsa &lt;jolsa@kernel.org&gt;
Cc: John Keeping &lt;john@metanate.com&gt;
Cc: Leo Yan &lt;leo.yan@linaro.org&gt;
Cc: Michael Petlan &lt;mpetlan@redhat.com&gt;
Cc: Namhyung Kim &lt;namhyung@kernel.org&gt;
Cc: Nathan Chancellor &lt;nathan@kernel.org&gt;
Cc: Nick Desaulniers &lt;ndesaulniers@google.com&gt;
Link: http://lore.kernel.org/lkml/YktYX2OnLtyobRYD@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo &lt;acme@redhat.com&gt;
</content>
</entry>
<entry>
<title>Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next</title>
<updated>2021-12-10T23:56:13+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2021-12-10T23:56:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.radix-linux.su/kernel/linux.git/commit/?id=be3158290db8376f49a92d30791dd8899f748aed'/>
<id>urn:sha1:be3158290db8376f49a92d30791dd8899f748aed</id>
<content type='text'>
Andrii Nakryiko says:

====================
bpf-next 2021-12-10 v2

We've added 115 non-merge commits during the last 26 day(s) which contain
a total of 182 files changed, 5747 insertions(+), 2564 deletions(-).

The main changes are:

1) Various samples fixes, from Alexander Lobakin.

2) BPF CO-RE support in kernel and light skeleton, from Alexei Starovoitov.

3) A batch of new unified APIs for libbpf, logging improvements, version
   querying, etc. Also a batch of old deprecations for old APIs and various
   bug fixes, in preparation for libbpf 1.0, from Andrii Nakryiko.

4) BPF documentation reorganization and improvements, from Christoph Hellwig
   and Dave Tucker.

5) Support for declarative initialization of BPF_MAP_TYPE_PROG_ARRAY in
   libbpf, from Hengqi Chen.

6) Verifier log fixes, from Hou Tao.

7) Runtime-bounded loops support with bpf_loop() helper, from Joanne Koong.

8) Extend branch record capturing to all platforms that support it,
   from Kajol Jain.

9) Light skeleton codegen improvements, from Kumar Kartikeya Dwivedi.

10) bpftool doc-generating script improvements, from Quentin Monnet.

11) Two libbpf v0.6 bug fixes, from Shuyi Cheng and Vincent Minet.

12) Deprecation warning fix for perf/bpf_counter, from Song Liu.

13) MAX_TAIL_CALL_CNT unification and MIPS build fix for libbpf,
    from Tiezhu Yang.

14) BTF_KING_TYPE_TAG follow-up fixes, from Yonghong Song.

15) Selftests fixes and improvements, from Ilya Leoshkevich, Jean-Philippe
    Brucker, Jiri Olsa, Maxim Mikityanskiy, Tirthendu Sarkar, Yucong Sun,
    and others.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (115 commits)
  libbpf: Add "bool skipped" to struct bpf_map
  libbpf: Fix typo in btf__dedup@LIBBPF_0.0.2 definition
  bpftool: Switch bpf_object__load_xattr() to bpf_object__load()
  selftests/bpf: Remove the only use of deprecated bpf_object__load_xattr()
  selftests/bpf: Add test for libbpf's custom log_buf behavior
  selftests/bpf: Replace all uses of bpf_load_btf() with bpf_btf_load()
  libbpf: Deprecate bpf_object__load_xattr()
  libbpf: Add per-program log buffer setter and getter
  libbpf: Preserve kernel error code and remove kprobe prog type guessing
  libbpf: Improve logging around BPF program loading
  libbpf: Allow passing user log setting through bpf_object_open_opts
  libbpf: Allow passing preallocated log_buf when loading BTF into kernel
  libbpf: Add OPTS-based bpf_btf_load() API
  libbpf: Fix bpf_prog_load() log_buf logic for log_level 0
  samples/bpf: Remove unneeded variable
  bpf: Remove redundant assignment to pointer t
  selftests/bpf: Fix a compilation warning
  perf/bpf_counter: Use bpf_map_create instead of bpf_create_map
  samples: bpf: Fix 'unknown warning group' build warning on Clang
  samples: bpf: Fix xdp_sample_user.o linking with Clang
  ...
====================

Link: https://lore.kernel.org/r/20211210234746.2100561-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
</entry>
</feed>
