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Arnaldo Carvalho de Melo 6276594115 perf llvm: Fix script used to obtain kernel make directives to work with new kbuild
Before this patch:

  # ./perf test 39 41
  39: LLVM search and compile                               :
  39.1: Basic BPF llvm compile                              : Ok
  39.2: kbuild searching                                    : FAILED!
  39.3: Compile source for BPF prologue generation          : Skip
  39.4: Compile source for BPF relocation                   : Skip
  41: BPF filter                                            :
  41.1: Basic BPF filtering                                 : Ok
  41.2: BPF pinning                                         : Ok
  41.3: BPF prologue generation                             : FAILED!
  41.4: BPF relocation checker                              : Skip
  #

Using 'perf test -v' for these tests shows that it is not finding
uapi/linux/fs.h, which ends up being because we don't setup the right header
path. Fix it.

After this patch:

  # perf test 39 41
  39: LLVM search and compile                               :
  39.1: Basic BPF llvm compile                              : Ok
  39.2: kbuild searching                                    : Ok
  39.3: Compile source for BPF prologue generation          : Ok
  39.4: Compile source for BPF relocation                   : Ok
  41: BPF filter                                            :
  41.1: Basic BPF filtering                                 : Ok
  41.2: BPF pinning                                         : Ok
  41.3: BPF prologue generation                             : Ok
  41.4: BPF relocation checker                              : Ok
  #

Longer description:

In llvm-utils.c we use some techniques to obtain the kbuild make
directives and that recently stopped working as now 'ar' gets called and
expects to find the dummy.o used to echo these variables:

  $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS)

Add the $(CC) line to satisfy that, making sure this works with all
kernels, i.e. preserving the temp directory and files in it used for
this technique we can see that it works everywhere:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ clean
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 4
  drwx------.  2 root root   80 Feb 14 09:42 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:42 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  #
  # cat /tmp/tmp.qgaFHgxjZ4/Makefile
  obj-y := dummy.o
  $(obj)/%.o: $(src)/%.c
          @echo -n "$(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS)"
          $(CC) -c -o $@ $<
  #

Then build with an old kernel Makefile:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ dummy.o
  -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/9/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h
  #
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 8
  drwx------.  2 root root  100 Feb 14 09:43 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:43 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  936 Feb 14 09:43 dummy.o
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  #

And a new one:

  # make -s -C /lib/modules/5.4.18-100.fc30.x86_64/build M=/tmp/tmp.qgaFHgxjZ4/ clean
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 4
  drwx------.  2 root root   80 Feb 14 09:43 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:43 ..
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  # make -s -C /lib/modules/5.6.0-rc1+/build M=/tmp/tmp.qgaFHgxjZ4/ dummy.o
   -nostdinc -isystem /usr/lib/gcc/x86_64-redhat-linux/9/include -I/home/acme/git/linux/arch/x86/include -I./arch/x86/include/generated -I/home/acme/git/linux/include -I./include -I/home/acme/git/linux/arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I/home/acme/git/linux/include/uapi -I./include/generated/uapi -include /home/acme/git/linux/include/linux/kconfig.h
  #
  # ls -la /tmp/tmp.qgaFHgxjZ4/
  total 16
  drwx------.  2 root root  160 Feb 14 09:44 .
  drwxrwxrwt. 47 root root 1200 Feb 14 09:44 ..
  -rw-r--r--.  1 root root  158 Feb 14 09:44 built-in.a
  -rw-r--r--.  1 root root  149 Feb 14 09:44 .built-in.a.cmd
  -rw-r--r--.  1 root root    0 Feb 13 17:14 dummy.c
  -rw-r--r--.  1 root root  936 Feb 14 09:44 dummy.o
  -rw-r--r--.  1 root root  121 Feb 13 17:14 Makefile
  -rw-r--r--.  1 root root    0 Feb 14 09:44 modules.order
  #

Reported-by: Thomas Richter <tmricht@linux.ibm.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: He Kuang <hekuang@huawei.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: Zefan Li <lizefan@huawei.com>
Link: https://www.spinics.net/lists/linux-perf-users/msg10600.html
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2020-02-14 10:06:00 -03:00
arch Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
block block-5.6-2020-02-05 2020-02-06 06:15:23 +00:00
certs certs: Add wrapper function to check blacklisted binary hash 2019-11-12 12:25:50 +11:00
crypto treewide: remove redundant IS_ERR() before error code check 2020-02-04 03:05:27 +00:00
Documentation Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
drivers Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
fs Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
include fs: New zonefs file system 2020-02-09 15:51:46 -08:00
init Tracing updates: 2020-02-06 07:12:11 +00:00
ipc proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
kernel Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
lib Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
net Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
samples Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
scripts Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
security Merge branch 'merge.nfs-fs_parse.1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-02-08 13:26:41 -08:00
sound sound fixes for 5.6-rc1 2020-02-06 14:15:01 +00:00
tools perf llvm: Fix script used to obtain kernel make directives to work with new kbuild 2020-02-14 10:06:00 -03:00
usr Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
virt KVM: fix overflow of zero page refcount with ksm running 2020-02-05 15:27:46 +01:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.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 modpost: dump missing namespaces into a single modules.nsdeps file 2019-11-11 20:10:01 +09:00
.mailmap A handful of small documentation fixes that wandered in. 2020-02-07 13:03:10 -08:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS open: introduce openat2(2) syscall 2020-01-18 09:19:18 -05:00
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 fs: New zonefs file system 2020-02-09 15:51:46 -08:00
Makefile Linux 5.6-rc1 2020-02-09 16:08:48 -08:00
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.