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Arnaldo Carvalho de Melo a88f70de1b perf build: Remove libaudit from the default feature checks
Ingo reported that the libaudit was always appearing as OFF:

  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                      libaudit: [ OFF ]

And everything seemed to work, i.e. we were checking for a feature that
we don't use, causing confusion for people building perf, so work to
remove that nuisance while making sure that it works when an arch
doesn't provide the alternative method to generate the syscall id/name
conversion tables.

Longer explanation of the new modus operandi:

  $ make -C tools/perf O=/tmp/build/perf NO_SYSCALL_TABLE=1
  <SNIP>
  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                        libbfd: [ on  ]
  ...                        libcap: [ on  ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ on  ]
  ...        numa_num_possible_cpus: [ on  ]
  ...                       libperl: [ on  ]
  ...                     libpython: [ on  ]
  ...                     libcrypto: [ on  ]
  ...                     libunwind: [ on  ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ on  ]
  ...                     get_cpuid: [ on  ]
  ...                           bpf: [ on  ]
  ...                        libaio: [ on  ]
  ...                       libzstd: [ on  ]
  ...        disassembler-four-args: [ on  ]

  Makefile.config:665: No libaudit.h found, disables 'trace' tool, please install audit-libs-devel or libaudit-dev
    GEN      /tmp/build/perf/common-cmds.h
    MKDIR    /tmp/build/perf/fd/
    MKDIR    /tmp/build/perf/fs/
  <SNIP>
  $

The libaudit test is forced and it fails when audit-libs-devel isn't available:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output
  test-libaudit.c:2:10: fatal error: libaudit.h: No such file or directory
      2 | #include <libaudit.h>
        |          ^~~~~~~~~~~~
  compilation terminated.
  $

If we install audit-libs-devel and rebuild it continues not to be shown as OFF
in the main auto-detection summary, but again gets tested and this time:

  $ rpm -q audit-libs-devel
  audit-libs-devel-3.0-0.15.20191104git1c2f876.fc31.x86_64
  $

The make output for the feature detection comes clean:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output

And the feature detection binary is successfully built and is dynamicly linked
with libaudit:

  $ ldd /tmp/build/perf/feature/test-libaudit.bin | grep audit
  	libaudit.so.1 => /lib64/libaudit.so.1 (0x00007f5bf5177000)
  $

As well as the resulting perf binary:

  $ ldd /tmp/build/perf/perf | grep audit
  	libaudit.so.1 => /lib64/libaudit.so.1 (0x00007fad511c7000)
  $

And 'perf trace' works using the libaudit method:

  $ sudo /tmp/build/perf/perf trace -e nanosleep sleep 1
       0.000 (1000.067 ms): sleep/281872 nanosleep(rqtp: 0x7ffedbbe69d0) = 0
  $

If we leave audit-libs-devel installed but don't disable the use of the best
method, the one using SYSCALL_TABLE, the default for architectures that provide
the script to build the syscall id/name mapping using the .tbl files copied
from the kernel sources, we get:

  $ rm -rf /tmp/build/perf ; mkdir -p /tmp/build/perf
  $ make -C tools/perf O=/tmp/build/perf
  Auto-detecting system features:
  ...                         dwarf: [ on  ]
  ...            dwarf_getlocations: [ on  ]
  ...                         glibc: [ on  ]
  ...                          gtk2: [ on  ]
  ...                        libbfd: [ on  ]
  ...                        libcap: [ on  ]
  ...                        libelf: [ on  ]
  ...                       libnuma: [ on  ]
  ...        numa_num_possible_cpus: [ on  ]
  ...                       libperl: [ on  ]
  ...                     libpython: [ on  ]
  ...                     libcrypto: [ on  ]
  ...                     libunwind: [ on  ]
  ...            libdw-dwarf-unwind: [ on  ]
  ...                          zlib: [ on  ]
  ...                          lzma: [ on  ]
  ...                     get_cpuid: [ on  ]
  ...                           bpf: [ on  ]
  ...                        libaio: [ on  ]
  ...                       libzstd: [ on  ]
  ...        disassembler-four-args: [ on  ]

    GEN      /tmp/build/perf/common-cmds.h
  <SNIP>
  $

Again, no mention of libaudit being on or OFF and:

  $ cat /tmp/build/perf/feature/test-libaudit.make.output
  cat: /tmp/build/perf/feature/test-libaudit.make.output: No such file or directory
  $

We didn't even bother checking for its availability, slightly speeding up the
build process and:

  $ ldd /tmp/build/perf/perf | grep libaudit
  $

We don't link with it, also:

  $ sudo /tmp/build/perf/perf trace -e nanosleep sleep 1
       0.000 (1000.053 ms): sleep/299125 nanosleep(rqtp: 0x7ffc24611b50) = 0
  $

And globs become available:

  $ sudo /tmp/build/perf/perf trace -e *sleep sleep 1
       0.000 (1000.072 ms): sleep/299136 nanosleep(rqtp: 0x7ffe7a3c4ff0) = 0
  $

Reported-by: Ingo Molnar <mingo@kernel.org>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-05-29 16:51:13 -03:00
arch perf/x86/rapl: Add AMD Fam17h RAPL support 2020-05-28 07:58:56 +02:00
block bdi: use bdi_dev_name() to get device name 2020-05-09 16:07:39 -06:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto gcc-10: avoid shadowing standard library 'free()' in crypto 2020-05-09 15:58:04 -07:00
Documentation Linux 5.7-rc7 2020-05-28 07:58:12 +02:00
drivers Linux 5.7-rc7 2020-05-28 07:58:12 +02:00
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-23 17:16:18 -07:00
include Linux 5.7-rc7 2020-05-28 07:58:12 +02:00
init A single fix for early boot crashes of kernels built with gcc10 and 2020-05-17 11:08:29 -07:00
ipc ipc/util.c: sysvipc_find_ipc() incorrectly updates position index 2020-05-14 10:00:35 -07:00
kernel Linux 5.7-rc7 2020-05-28 07:58:12 +02:00
lib vsprintf: don't obfuscate NULL and error pointers 2020-05-19 11:35:38 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm z3fold: fix use-after-free when freeing handles 2020-05-23 10:26:32 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-23 17:16:18 -07:00
samples Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-05-15 13:10:06 -07:00
scripts scripts/gdb: repair rb_first() and rb_last() 2020-05-07 19:27:20 -07:00
security Linux 5.7-rc7 2020-05-28 07:58:12 +02:00
sound sound fixes for 5.7-rc7 2020-05-22 09:22:22 -07:00
tools perf build: Remove libaudit from the default feature checks 2020-05-29 16:51:13 -03:00
usr kbuild: fix comment about missing include guard detection 2020-04-11 12:09:48 +09:00
virt KVM: Introduce kvm_make_all_cpus_request_except() 2020-05-08 07:44:32 -04:00
.clang-format clang-format: Update with the latest for_each macro list 2020-04-18 13:49:33 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
.mailmap i2c: use my kernel.org address from now on 2020-05-05 16:29:09 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Hand MIPS over to Thomas 2020-02-24 22:43:18 -08:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS Merge branch 'akpm' (patches from Andrew) 2020-05-23 11:21:47 -07:00
Makefile Linux 5.7-rc7 2020-05-24 15:32:54 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.