linux/tools
Thomas Richter 83868bf71d perf build: Fix installation directory for eBPF
The perf tool build and install is controlled via a Makefile. The
'install' rule creates directories and copies files. Among them are
header files installed in /usr/lib/include/perf/bpf/.

However all listed examples are installing its header files in

  /usr/lib/<tool-name>/...[/include]/header.h

and not in

  /usr/lib/include/<tool-name>/.../header.h.

Background information:

Building the Fedora 28 glibc RPM on s390x and s390 fails on s390 (gcc
-m31) as gcc is not able to find header-files like stdbool.h.

In the glibc.spec file, you can see that glibc is configured with
"--with-headers". In this case, first -nostdinc is added to the CFLAGS
and then further include paths are added via -isystem.  One of those
paths should contain header files like stdbool.h.

In order to get this path, gcc is invoked with:

- on Fedora 28 (with 4.18 kernel):

  $ gcc -print-file-name=include
  /usr/lib/gcc/s390x-redhat-linux/8/include
  $ gcc -m31 -print-file-name=include
  /usr/lib/gcc/s390x-redhat-linux/8/../../../../lib/include
  => If perf is installed, this is: /usr/lib/include
  On my machine this directory is only containing the directory "perf".
  If perf is not installed gcc returns: /usr/lib/gcc/s390x-redhat-linux/8/include

- on Ubuntu 18.04 (with 4.15 kernel):

  $ gcc  -print-file-name=include
  /usr/lib/gcc/s390x-linux-gnu/7/include
  $ gcc -m31 -print-file-name=include
  /usr/lib/gcc/s390x-linux-gnu/7/include
  => gcc returns the correct path even if perf is installed.

In each case, the introduction of the subdirectory /usr/lib/include
leads to the regression that one can not build the glibc RPM for s390
anymore as gcc can not find headers like stdbool.h.

To remedy this install bpf.h to /usr/lib/perf/include/bpf/bpf.h

Output before using the command 'perf test -Fv 40':

  echo '...[bpf-program-source]...' | /usr/bin/clang ... \
		   -I/root/lib/include/perf/bpf ...
                               ^^^^^^^^^^^^
...
  [root@p23lp27 perf]# perf test -F 40
  40: BPF filter                                            :
  40.1: Basic BPF filtering                                 : Ok
  40.2: BPF pinning                                         : Ok
  40.3: BPF prologue generation                             : Ok
  40.4: BPF relocation checker                              : Ok
  [root@p23lp27 perf]#

Output after using command 'perf test -Fv 40':

  echo '...[bpf-program-source]...' | /usr/bin/clang ... \
		 -I/root/lib/perf/include/bpf ...
                             ^^^^^^^^^^^^
...
  [root@p23lp27 perf]# perf test -F 40
  40: BPF filter                                            :
  40.1: Basic BPF filtering                                 : Ok
  40.2: BPF pinning                                         : Ok
  40.3: BPF prologue generation                             : Ok
  40.4: BPF relocation checker                              : Ok
  [root@p23lp27 perf]#

Committer testing:

While the above 'perf test -F 40' (or 'perf test bpf') will allow us
to see that the correct path is now added via -I, to actually test this
we better try to use a bpf script that includes files in the changed
directory.

We have the files that now reside in /root/lib/perf/examples/bpf/ to do
just that:

  # tail -8 /root/lib/perf/examples/bpf/5sec.c
  #include <bpf.h>

  int probe(hrtimer_nanosleep, rqtp->tv_sec)(void *ctx, int err, long sec)
  {
	  return sec == 5;
  }

  license(GPL);
  # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 4
       0.333 (4000.086 ms): sleep/9248 nanosleep(rqtp: 0x7ffc155f3300) = 0
  # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 5
       0.287 (         ): sleep/9659 nanosleep(rqtp: 0x7ffeafe38200) ...
       0.290 (         ): perf_bpf_probe:hrtimer_nanosleep:(ffffffff9911efe0) tv_sec=5
       0.287 (5000.059 ms): sleep/9659  ... [continued]: nanosleep()) = 0
  # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 6
       0.247 (5999.951 ms): sleep/10068 nanosleep(rqtp: 0x7fff2086d900) = 0
  # perf trace -e *sleep -e /root/lib/perf/examples/bpf/5sec.c sleep 5.987
       0.293 (         ): sleep/10489 nanosleep(rqtp: 0x7ffdd4fc10e0) ...
       0.296 (         ): perf_bpf_probe:hrtimer_nanosleep:(ffffffff9911efe0) tv_sec=5
       0.293 (5986.912 ms): sleep/10489  ... [continued]: nanosleep()) = 0
  #

Suggested-by: Stefan Liebler <stli@linux.ibm.com>
Suggested-by: Arnaldo Carvalho de Melo <acme@kernel.org>
Signed-off-by: Thomas Richter <tmricht@linux.ibm.com>
Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Fixes: 1b16fffa38 ("perf llvm-utils: Add bpf include path to clang command line")
Link: http://lkml.kernel.org/r/20180731073254.91090-1-tmricht@linux.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2018-07-31 10:54:50 -03:00
..
accounting
arch Merge remote-tracking branch 'tip/perf/urgent' into perf/core 2018-07-31 09:55:45 -03:00
bpf tools/bpftool: Fix segfault case regarding 'pin' arguments 2018-07-20 10:16:54 +02:00
build tools: build: Use HOSTLDFLAGS with fixdep 2018-07-13 00:48:18 +09:00
cgroup tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
firewire
gpio Linux 4.16-rc5 2018-03-18 17:48:59 +01:00
hv tools: hv: include string.h in hv_fcopy_daemon 2018-03-06 09:57:16 -08:00
iio tools: iio: iio_generic_buffer: allow continuous looping 2018-05-20 14:55:58 +01:00
include tools include uapi: Grab a copy of linux/in.h 2018-07-31 10:52:37 -03:00
kvm/kvm_stat tools/kvm_stat: Remove unused function 2018-03-28 22:47:06 +02:00
laptop tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
leds tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
lib docs: Fix some broken references 2018-06-15 18:10:01 -03:00
memory-model tools/memory-model: Add reference for 'Simplifying ARM concurrency' 2018-05-15 08:11:19 +02:00
nfsd
objtool objtool: Use '.strtab' if '.shstrtab' doesn't exist, to support ORC tables on Clang 2018-07-14 14:59:42 +02:00
pci
pcmcia
perf perf build: Fix installation directory for eBPF 2018-07-31 10:54:50 -03:00
power Merge branch 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux 2018-06-21 00:37:04 +02:00
scripts Kbuild: fix # escaping in .cmd files for future Make 2018-04-11 00:03:02 +09:00
spi tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
testing Various fixes to the tracing infrastructure: 2018-07-27 09:50:33 -07:00
thermal/tmon tools/thermal: tmon: fix for segfault 2018-03-27 09:51:23 +02:00
time
usb tools: usb: ffs-test: Fix build on big endian systems 2018-07-17 10:12:51 +03:00
virtio sg: remove ->sg_magic member 2018-06-29 08:48:06 -06:00
vm mm: mark pages in use for page tables 2018-06-07 17:34:37 -07:00
wmi tools: fix cross-compile var clobbering 2018-02-21 15:35:42 -08:00
Makefile