linux/tools
Wang Nan 4a4f66a1a7 perf llvm: Pass LINUX_VERSION_CODE to BPF program when compiling
Arnaldo suggests to make LINUX_VERSION_CODE works like __func__ and
__FILE__ so user don't need to care setting right linux version too
much. In this patch, perf llvm transfers LINUX_VERSION_CODE macro
through clang cmdline.

[1] http://lkml.kernel.org/r/20151029223744.GK2923@kernel.org

Committer notes:

Before, forgetting to update the version:

  # uname -r
  4.3.0-rc1+
  # cat bpf.c
  __attribute__((section("fork=_do_fork"), used))
  int fork(void *ctx)
  {
          return 1;
  }

  char _license[] __attribute__((section("license"), used)) = "GPL";
  int _version __attribute__((section("version"), used)) = 0x40200;
  #
  # perf record -e bpf.c sleep 1
  event syntax error: 'bpf.c'
                       \___ Invalid argument: Are you root and runing a CONFIG_BPF_SYSCALL kernel?

  (add -v to see detail)
  Run 'perf list' for a list of valid events

   Usage: perf record [<options>] [<command>]
      or: perf record [<options>] -- <command> [<options>]

      -e, --event <event>   event selector. use 'perf list' to list available events
 #

After:

  # grep version bpf.c
  int _version __attribute__((section("version"), used)) = LINUX_VERSION_CODE;
  # perf record -e bpf.c sleep 1
  [ perf record: Woken up 1 times to write data ]
  [ perf record: Captured and wrote 0.017 MB perf.data ]
  # perf evlist -v
  perf_bpf_probe:fork: type: 2, size: 112, config: 0x5ee, { sample_period,
  sample_freq }: 1, sample_type: IP|TID|TIME|CPU|PERIOD|RAW, disabled: 1,
  inherit: 1, mmap: 1, comm: 1, enable_on_exec: 1, task: 1, sample_id_all:
  1, exclude_guest: 1, mmap2: 1, comm_exec: 1
  #

Suggested-and-Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Wang Nan <wangnan0@huawei.com>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Zefan Li <lizefan@huawei.com>
Cc: pi3orama@163.com
Link: http://lkml.kernel.org/r/1446636007-239722-3-git-send-email-wangnan0@huawei.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2015-11-05 12:47:50 -03:00
..
arch tools include: Add basic atomic.h implementation from the kernel sources 2015-05-08 16:11:05 -03:00
build tools build: Fix libiberty feature detection 2015-10-29 17:46:35 -03:00
cgroup
firewire
hv tools: hv: add a python script lsvmbus to list VMBus devices 2015-08-05 11:44:29 -07:00
iio iio: lsiio: fix error code handling error 2015-08-12 19:26:22 +01:00
include tools include: Fix strict-aliasing rules breakage 2015-10-13 11:43:16 -03:00
laptop/freefall Move freefall program from Documentation/ to tools/ 2015-06-08 16:42:07 -06:00
lguest tools/lguest: Clean up include dir 2015-08-26 06:12:35 +02:00
lib tools lib bpf: Fix compiler warning on CentOS 6 2015-11-03 12:13:31 -03:00
net bpf_jit_disasm: also support reading jit dump from file 2015-07-31 15:13:14 -07:00
nfsd
perf perf llvm: Pass LINUX_VERSION_CODE to BPF program when compiling 2015-11-05 12:47:50 -03:00
power tools/power turbosat: update version number 2015-09-26 09:49:55 -04:00
scripts
testing membarrier: clean up selftest 2015-09-22 15:09:53 -07:00
thermal/tmon tools/thermal: tmon: fixed the 'make install' command 2015-05-09 13:36:58 +08:00
time
usb
virtio tools/virtio: propagate V=X to kernel build 2015-09-16 12:48:07 +03:00
vm tools vm: Fix build due to removal of tools/lib/api/fs/debugfs.h 2015-09-22 22:42:39 -03:00
Makefile Staging driver patches for 4.2-rc1 2015-06-26 15:46:08 -07:00