982be47751
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 '<btf__raw_data>:' -A20
00000000005b3050 <btf__raw_data>:
{
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 <btf__raw_data+0x2c>
}
5b3076: c9 leave
return btf__get_raw_data(btf_ro, size);
5b3077: e9 14 99 e5 ff jmp 40c990 <btf__get_raw_data@plt>
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 <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.