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On ia64 and ppc64, function pointers do not point to the
entry address of the function, but to the address of a
function descriptor (which contains the entry address and misc
data).

Since the kprobes code passes the function pointer stored
by NOKPROBE_SYMBOL() to kallsyms_lookup_size_offset() for
initalizing its blacklist, it fails and reports many errors,
such as:

  Failed to find blacklist 0001013168300000
  Failed to find blacklist 0001013000f0a000
  [...]

To fix this bug, use arch_deref_entry_point() to get the
function entry address for kallsyms_lookup_size_offset()
instead of the raw function pointer.

Suzuki also pointed out that blacklist entries should also
be updated as well.
Reported-by: Tony Luck <tony.luck@gmail.com>
Fixed-by: Suzuki K. Poulose <suzuki@in.ibm.com>
Tested-by: Tony Luck <tony.luck@intel.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (for powerpc)
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: sparse@chrisli.org
Cc: Paul Mackerras <paulus@samba.org>
Cc: akataria@vmware.com
Cc: anil.s.keshavamurthy@intel.com
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Kevin Hao <haokexin@gmail.com>
Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: rdunlap@infradead.org
Cc: dl9pf@gmx.de
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20140717114411.13401.2632.stgit@kbuild-fedora.novalocal

Signed-off-by: Ingo Molnar <mingo@kernel.org>