commit f6537f2f0eba4eba3354e48dbe3047db6d8b6254 upstream.

This patch uses CONFIG_PAGE_OFFSET to filter symbols which
are not in kernel address space because these symbols are
generally for generating code purpose and can't be run at
kernel mode, so we needn't keep them in /proc/kallsyms.

For example, on ARM there are some symbols which may be
linked in relocatable code section, then perf can't parse
symbols any more from /proc/kallsyms, this patch fixes the
problem (introduced b9b32bf70f2fb710b07c94e13afbc729afe221da)

Cc: Russell King <linux@arm.linux.org.uk>
Cc: linux-arm-kernel@lists.infradead.org
Cc: Michal Marek <mmarek@suse.cz>
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

We have CONFIG_SYMBOL_PREFIX, which three archs define to the string
"_".  But Al Viro broke this in "consolidate cond_syscall and
SYSCALL_ALIAS declarations" (in linux-next), and he's not the first to
do so.

Using CONFIG_SYMBOL_PREFIX is awkward, since we usually just want to
prefix it so something.  So various places define helpers which are
defined to nothing if CONFIG_SYMBOL_PREFIX isn't set:

1) include/asm-generic/unistd.h defines __SYMBOL_PREFIX.
2) include/asm-generic/vmlinux.lds.h defines VMLINUX_SYMBOL(sym)
3) include/linux/export.h defines MODULE_SYMBOL_PREFIX.
4) include/linux/kernel.h defines SYMBOL_PREFIX (which differs from #7)
5) kernel/modsign_certificate.S defines ASM_SYMBOL(sym)
6) scripts/modpost.c defines MODULE_SYMBOL_PREFIX
7) scripts/Makefile.lib defines SYMBOL_PREFIX on the commandline if
   CONFIG_SYMBOL_PREFIX is set, so that we have a non-string version
   for pasting.

(arch/h8300/include/asm/linkage.h defines SYMBOL_NAME(), too).

Let's solve this properly:
1) No more generic prefix, just CONFIG_HAVE_UNDERSCORE_SYMBOL_PREFIX.
2) Make linux/export.h usable from asm.
3) Define VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR().
4) Make everyone use them.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: James Hogan <james.hogan@imgtec.com>
Tested-by: James Hogan <james.hogan@imgtec.com> (metag)

The shell '.' command is not required to search the current directory as
a fallback and in fact newer versions of bash in sh-mode do not do this.
Force reading the file from the current directory if $KCONFIG_CONFIG
contains no '/'.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Michal Marek <mmarek@suse.cz>

Its possible to superseed the config file with KCONFIG_CONFIG and have
completely no .config in the tree. The current script is sourcing
.config in every case, so the kernel will never build succesfully. This
patch fixes that issue by sourcing KCONFIG_CONFIG instead.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>

Pull blackfin updates from Bob Liu:
 "One kbuild and a smp build fix."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lliubbo/blackfin:
  kbuild: add symbol prefix arg to kallsyms
  blackfin: smp: adapt to generic smp helpers

Commit 1f2bfbd00e466ff3489b2ca5cc75b1cccd14c123 ("kbuild: link of
vmlinux moved to a script") introduced in v3.5-rc1 broke kallsyms on
architectures which have symbol prefixes.

The --symbol-prefix argument used to be added to the KALLSYMS command
line from the architecture Makefile, however this isn't picked up by the
new scripts/link-vmlinux.sh. This resulted in symbols like
kallsyms_addresses being added which weren't correctly overriding the
weak symbols such as _kallsyms_addresses. These could then trigger
BUG_ONs in kallsyms code.

This is fixed by removing the KALLSYMS addition from the architecture
Makefile, and using CONFIG_SYMBOL_PREFIX in the link-vmlinux.sh script
to determine whether to add the --symbol-prefix argument.

Signed-off-by: James Hogan <james.hogan@imgtec.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>

Reported-by: Jan Engelhardt <jengelh@inai.de>
Signed-off-by: Michal Marek <mmarek@suse.cz>

... at least in the top-level Makefile and scripts/link-vmlinux.sh.
There are some more instances of the 'echo <error>; exit 1' pattern in
some arch Makefiles and kconfig.

Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>

Pull kbuild updates from Michal Marek.

Fixed up nontrivial merge conflict in Makefile as per Stephen Rothwell
and linux-next (and trivial arch/sparc/Makefile changes due to removed
sparc32 logic).

* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
  mips: Fix KBUILD_CPPFLAGS definition
  kbuild: fix ia64 link
  kbuild: document KBUILD_LDS, KBUILD_VMLINUX_{INIT,MAIN} and LDFLAGS_vmlinux
  kbuild: link of vmlinux moved to a script
  kbuild: refactor final link of sparc32
  kbuild: drop unused KBUILD_VMLINUX_OBJS from top-level Makefile
  kbuild: Makefile: remove unnecessary check for m68knommu ARCH

ia64 build failed like this:

  CC      init/version.o
  LD      init/built-in.o
  KSYM    .tmp_kallsyms1.o
ld: .tmp_kallsyms1.o: linking constant-gp files with non-constant-gp files
ld: failed to merge target specific data of file .tmp_kallsyms1.o
make: *** [vmlinux] Error 1

This was introduced when link of vmlinux was migrated to a script.
Add missing option to as to fix this.

Reported-by: Tony Luck <tony.luck@gmail.com>
Tested-by: Tony Luck <tony.luck@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Michal Marek <mmarek@suse.cz>