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5c83eff381
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 '<bpf_prog_load>:' -A20
00000000005b2d70 <bpf_prog_load>:
{
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 <bpf_load_program@plt>
}
$
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Ilya Leoshkevich <iii@linux.ibm.com>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Thomas Richter <tmricht@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/linux-perf-users/YozLKby7ITEtchC9@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.