This reverts commit 079787f2.

Below commit already resolve a cross build problem.
I have been noticed this too lately.

    commit 3c4797d4
    Author: Rabin Vincent <rabin@rab.in>
    Date:   Fri May 17 22:27:44 2013 +0200

    tools lib lk: Respect CROSS_COMPILE

    Make lk use CROSS_COMPILE, in order to be able to cross compile perf
    again.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1373936614-22224-1-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Since libelf sometimes uses libpthread, we have to list that after -lelf
when someone tries to build statically.  Else things go boom:

Makefile:479: *** No libelf.h/libelf found, please install \
	libelf-dev/elfutils-libelf-devel.  Stop.

Similarly, the -ldw test fails as it often uses -lz:

Makefile:462: No libdw.h found or old libdw.h found or elfutils is older \
	than 0.138, disables dwarf support. Please install new elfutils-devel/libdw-dev

And if we add debugging to try-cc, we see:
+ echo '#include <dwarf.h>

int main(void)
{
        Dwarf *dbg = dwarf_begin(0, DWARF_C_READ);
        return (long)dbg;
}'
+ i686-pc-linux-gnu-gcc -x c - -O2 -pipe -march=atom -mtune=atom -mfpmath=sse -g \
	-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE \
	-ldw -lelf -static -lpthread -lrt -lelf -lm -o .24368
/usr/lib/libdw.a(dwarf_begin_elf.o):function check_section.isra.1: error: undefined reference to 'inflateInit_'
/usr/lib/libdw.a(dwarf_begin_elf.o):function check_section.isra.1: error: undefined reference to 'inflate'
/usr/lib/libdw.a(dwarf_begin_elf.o):function check_section.isra.1: error: undefined reference to 'inflateReset'
/usr/lib/libdw.a(dwarf_begin_elf.o):function check_section.isra.1: error: undefined reference to 'inflateEnd'

+ echo '#include <libelf.h>

int main(void)
{
        Elf *elf = elf_begin(0, ELF_C_READ, 0);
        return (long)elf;
}'
+ i686-pc-linux-gnu-gcc -x c - -O2 -pipe -march=atom -mtune=atom -mfpmath=sse -g \
	-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64 -D_GNU_SOURCE \
	-static -lpthread -lrt -lelf -lm -o .19216
/usr/lib/libelf.a(elf_begin.o):function file_read_elf: error: undefined reference to 'pthread_rwlock_init'
/usr/lib/libelf.a(elf_begin.o):function __libelf_read_mmaped_file: error: undefined reference to 'pthread_rwlock_init'
/usr/lib/libelf.a(elf_begin.o):function __libelf_read_mmaped_file: error: undefined reference to 'pthread_rwlock_init'
/usr/lib/libelf.a(elf_begin.o):function read_file: error: undefined reference to 'pthread_rwlock_init'
/usr/lib/libelf.a(elf_begin.o):function lock_dup_elf.8072: error: undefined reference to 'pthread_rwlock_unlock'
/usr/lib/libelf.a(elf_begin.o):function lock_dup_elf.8072: error: undefined reference to 'pthread_rwlock_wrlock'
/usr/lib/libelf.a(elf_begin.o):function elf_begin: error: undefined reference to 'pthread_rwlock_rdlock'
/usr/lib/libelf.a(elf_begin.o):function elf_begin: error: undefined reference to 'pthread_rwlock_unlock'
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1368073064-18276-1-git-send-email-vapier@gentoo.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Currently, lib lk doesn't use CROSS_COMPILE environment variable, so
cross build always fails.

This is a quick fix for this problem.
Signed-off-by: NJoonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1371603750-15053-2-git-send-email-iamjoonsoo.kim@lge.comSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Make lk use CROSS_COMPILE, in order to be able to cross compile perf
again.
Signed-off-by: NRabin Vincent <rabin@rab.in>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Borislav Petkov <bp@suse.de>
Link: http://lkml.kernel.org/r/1368822464-4887-1-git-send-email-rabin@rab.inSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

Jiri Olsa triggers the following build error:

    SUBDIR ../lib/lk/
    CC debugfs.o
In file included from /usr/include/errno.h:29:0,
                 from debugfs.c:1:
/usr/include/features.h:314:4: error: #warning _FORTIFY_SOURCE requires compiling with optimization (-O) [-Werror=cpp]

This is because enabling buffer overflow checks through _FORTIFY_SOURCE
require compiler optimizations to be enabled too. However, those are
not. Enable them by simply copying the perf optimization level. It can
be expanded later if we want to support debug builds, etc.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Reported-by: NJiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1362338733-8718-1-git-send-email-bp@alien8.deSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

This introduces the tools/lib/lk library, that will gradually have the
routines that now are used in tools/perf/ and other tools and that can
be shared.

Start by carving out debugfs routines for general use.
Signed-off-by: NBorislav Petkov <bp@suse.de>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1361374353-30385-5-git-send-email-bp@alien8.de
[ committer note: Add tools/lib/lk/ to perf's MANIFEST so that its tarballs continue to build ]
Signed-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>