linux-dev/tools/build, branch linus/master

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

2022-05-26T15:36:56Z

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

2022-05-26T14:02:02Z

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

2022-05-26T14:02:02Z

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

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

2022-05-26T14:02:02Z

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 ':' -A20 00000000005b2dc0 : { 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 } 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 $ 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_prog_load() to handle older libbpf versions

2022-05-26T14:02:02Z

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 ':' -A20 00000000005b2d70 : { 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 } $ 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: Fix btf__load_from_kernel_by_id() feature check

2022-05-26T14:02:02Z

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 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: Fix check for btf__load_from_kernel_by_id() in libbpf

2022-05-20T12:45:41Z

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 00000000005ba180 : #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, &btf); 5ba197: 48 8d 75 f0 lea -0x10(%rbp),%rsi 5ba19b: e8 a0 57 e5 ff call 40f940 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 } Fixes: 218e7b775d368f38 ("perf bpf: Provide a weak btf__load_from_kernel_by_id() for older libbpf versions") Reported-by: Avi Kivity Link: https://lore.kernel.org/linux-perf-users/f0add43b-3de5-20c5-22c4-70aff4af959f@scylladb.com Cc: Adrian Hunter Cc: Ian Rogers Cc: Jiri Olsa Cc: Namhyung Kim Link: https://lore.kernel.org/linux-perf-users/YobjjFOblY4Xvwo7@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools build: Filter out options and warnings not supported by clang

2022-04-09T15:34:16Z

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>>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: acme> And then get to the problems at the end of this message, which seem acme> similar to the problem described here: acme> acme> From Nathan Chancellor <> acme> Subject [PATCH] mwifiex: Remove unnecessary braces from HostCmd_SET_SEQ_NO_BSS_INFO acme> acme> https://lkml.org/lkml/2020/9/1/135 acme> acme> So perhaps in this case its better to disable that acme> -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. Based-on-a-patch-by: Sedat Dilek Tested-by: Sedat Dilek # Debian/Selfmade LLVM-14 (x86-64) Cc: Adrian Hunter Cc: Fangrui Song Cc: Florian Fainelli Cc: Ian Rogers Cc: Jiri Olsa Cc: John Keeping Cc: Leo Yan Cc: Michael Petlan Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Link: http://lore.kernel.org/lkml/YkxWcYzph5pC1EK8@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

tools build: Use $(shell ) instead of `` to get embedded libperl's ccopts

2022-04-09T15:33:38Z

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 # Debian/Selfmade LLVM-14 (x86-64) Cc: Adrian Hunter Cc: Fangrui Song Cc: Florian Fainelli Cc: Ian Rogers Cc: Jiri Olsa Cc: John Keeping Cc: Leo Yan Cc: Michael Petlan Cc: Namhyung Kim Cc: Nathan Chancellor Cc: Nick Desaulniers Link: http://lore.kernel.org/lkml/YktYX2OnLtyobRYD@kernel.org Signed-off-by: Arnaldo Carvalho de Melo

kbuild: replace $(if A,A,B) with $(or A,B)

2022-02-15T03:25:56Z

$(or ...) is available since GNU Make 3.81, and useful to shorten the code in some places. Covert as follows: $(if A,A,B) --> $(or A,B) This patch also converts: $(if A, A, B) --> $(or A, B) Strictly speaking, the latter is not an equivalent conversion because GNU Make keeps spaces after commas; if A is not empty, $(if A, A, B) expands to " A", while $(or A, B) expands to "A". Anyway, preceding spaces are not significant in the code hunks I touched. Signed-off-by: Masahiro Yamada Reviewed-by: Nicolas Schier

linux-dev/tools/build, branch linus/master

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

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

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

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

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

perf build: Fix btf__load_from_kernel_by_id() feature check

perf build: Fix check for btf__load_from_kernel_by_id() in libbpf

tools build: Filter out options and warnings not supported by clang

tools build: Use $(shell ) instead of `` to get embedded libperl's ccopts

kbuild: replace $(if A,A,B) with $(or A,B)

perf build: Stop using weak btfraw_data() to handle older libbpf versions