For the cases that some kernel (module) path stamps the crash reserved
memory(already mapped by the kernel) where has been loaded the second
kernel data, the kdump kernel will probably fail to boot when panic
happens (or even not happens) leaving the culprit at large, this is
unacceptable.

The patch introduces a mechanism for detecting such cases:

1) After each crash kexec loading, it simply marks the reserved memory
   regions readonly since we no longer access it after that.  When someone
   stamps the region, the first kernel will panic and trigger the kdump.
   The weak arch_kexec_protect_crashkres() is introduced to do the actual
   protection.

2) To allow multiple loading, once 1) was done we also need to remark
   the reserved memory to readwrite each time a system call related to
   kdump is made.  The weak arch_kexec_unprotect_crashkres() is introduced
   to do the actual protection.

The architecture can make its specific implementation by overriding
arch_kexec_protect_crashkres() and arch_kexec_unprotect_crashkres().
Signed-off-by: NXunlei Pang <xlpang@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Minfei Huang <mhuang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

remove_arg_zero() does free_arg_page() for no reason.  This was needed
before and only if CONFIG_MMU=y: see commit 4fc75ff4 ("exec: fix
remove_arg_zero"), install_arg_page() was called for every page != NULL
in bprm->page[] array.  Today install_arg_page() has already gone and
free_arg_page() is nop after another commit b6a2fea3 ("mm: variable
length argument support").

CONFIG_MMU=n does free_arg_pages() in free_bprm() and thus it doesn't
need remove_arg_zero()->free_arg_page() too; apart from get_arg_page()
it never checks if the page in bprm->page[] was allocated or not, so the
"extra" non-freed page is fine.  OTOH, this free_arg_page() can add the
minor pessimization, the caller is going to do copy_strings_kernel()
right after remove_arg_zero() which will likely need to re-allocate the
same page again.

And as Hujunjie pointed out, the "offset == PAGE_SIZE" check is wrong
because we are going to increment bprm->p once again before return, so
CONFIG_MMU=n "leaks" the page anyway if '0' is the final byte in this
page.

NOTE: remove_arg_zero() assumes that argv[0] is null-terminated but this
is not necessarily true.  copy_strings() does "len = strnlen_user(...)",
then copy_from_user(len) but another thread or debuger can overwrite the
trailing '0' in between.  Afaics nothing really bad can happen because
we must always have the null-terminated bprm->filename copied by the 1st
copy_strings_kernel(), but perhaps we should change this code to check
"bprm->p < bprm->exec" anyway, and/or change copy_strings() to ensure
that the last byte in string is always zero.

Link: http://lkml.kernel.org/r/20160517155335.GA31435@redhat.comSigned-off-by: NOleg Nesterov <oleg@redhat.com>
Reported by: hujunjie <jj.net@163.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Linux preallocates the task structs of the idle tasks for all possible
CPUs.  This currently means they all end up on node 0.  This also
implies that the cache line of MWAIT, which is around the flags field in
the task struct, are all located in node 0.

We see a noticeable performance improvement on Knights Landing CPUs when
the cache lines used for MWAIT are located in the local nodes of the
CPUs using them.  I would expect this to give a (likely slight)
improvement on other systems too.

The patch implements placing the idle task in the node of its CPUs, by
passing the right target node to copy_process()

[akpm@linux-foundation.org: use NUMA_NO_NODE, not a bare -1]
Link: http://lkml.kernel.org/r/1463492694-15833-1-git-send-email-andi@firstfloor.orgSigned-off-by: NAndi Kleen <ak@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

All the users of siginmask() must ensure that sig < SIGRTMIN.  sig_fatal()
doesn't and this is wrong:

	UBSAN: Undefined behaviour in kernel/signal.c:911:6
	shift exponent 32 is too large for 32-bit type 'long unsigned int'

the patch doesn't add the neccesary check to sig_fatal(), it moves the
check into siginmask() and updates other callers.

Link: http://lkml.kernel.org/r/20160517195052.GA15187@redhat.comReported-by: NMeelis Roos <mroos@linux.ee>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Use pr_<level> instead of printk(KERN_<LEVEL> ).
Signed-off-by: NWang Xiaoqiang <wangxq10@lzu.edu.cn>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Currently the size of "struct signal_struct"->oom_flags member is
sizeof(unsigned) bytes, but only one flag OOM_FLAG_ORIGIN which is
updated by current thread is defined.  We can convert OOM_FLAG_ORIGIN
into a bool, and reuse the saved bytes for updating from the OOM killer
and/or the OOM reaper thread.

By the way, do we care about a race window between run_store() and
swapoff() because it would be theoretically possible that two threads
sharing the "struct signal_struct" concurrently call respective
functions? If we care, we can make oom_flags an atomic_t.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I see no reason why waitid() can't support other linux-specific flags
allowed in sys_wait4().

In particular this change can help if we reconsider the previous change
("wait/ptrace: assume __WALL if the child is traced") which adds the
"automagical" __WALL for debugger.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: <syzkaller@googlegroups.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The following program (simplified version of generated by syzkaller)

	#include <pthread.h>
	#include <unistd.h>
	#include <sys/ptrace.h>
	#include <stdio.h>
	#include <signal.h>

	void *thread_func(void *arg)
	{
		ptrace(PTRACE_TRACEME, 0,0,0);
		return 0;
	}

	int main(void)
	{
		pthread_t thread;

		if (fork())
			return 0;

		while (getppid() != 1)
			;

		pthread_create(&thread, NULL, thread_func, NULL);
		pthread_join(thread, NULL);
		return 0;
	}

creates an unreapable zombie if /sbin/init doesn't use __WALL.

This is not a kernel bug, at least in a sense that everything works as
expected: debugger should reap a traced sub-thread before it can reap the
leader, but without __WALL/__WCLONE do_wait() ignores sub-threads.

Unfortunately, it seems that /sbin/init in most (all?) distributions
doesn't use it and we have to change the kernel to avoid the problem.
Note also that most init's use sys_waitid() which doesn't allow __WALL, so
the necessary user-space fix is not that trivial.

This patch just adds the "ptrace" check into eligible_child().  To some
degree this matches the "tsk->ptrace" in exit_notify(), ->exit_signal is
mostly ignored when the tracee reports to debugger.  Or WSTOPPED, the
tracer doesn't need to set this flag to wait for the stopped tracee.

This obviously means the user-visible change: __WCLONE and __WALL no
longer have any meaning for debugger.  And I can only hope that this won't
break something, but at least strace/gdb won't suffer.

We could make a more conservative change.  Say, we can take __WCLONE into
account, or !thread_group_leader().  But it would be nice to not
complicate these historical/confusing checks.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Reported-by: NDmitry Vyukov <dvyukov@google.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Jan Kratochvil <jan.kratochvil@redhat.com>
Cc: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Cc: Pedro Alves <palves@redhat.com>
Cc: Roland McGrath <roland@hack.frob.com>
Cc: <syzkaller@googlegroups.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes block comments with proper formatting to eliminate the
following checkpatch.pl warnings:

  "WARNING: Block comments use * on subsequent lines"
  "WARNING: Block comments use a trailing */ on a separate line"

Link: http://lkml.kernel.org/r/1462886671-3521-8-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes checkpatch.pl warning "WARNING: Single statement macros
should not use a do {} while (0) loop".

Link: http://lkml.kernel.org/r/1462886671-3521-7-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes the checkpatch.pl warning that suggests else is not
generally useful after a break or return.

Link: http://lkml.kernel.org/r/1462886671-3521-6-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to
bare use of 'unsigned'".

Link: http://lkml.kernel.org/r/1462886671-3521-5-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes checkpatch.pl warning "WARNING: suspect code indent for
conditional statements".

Link: http://lkml.kernel.org/r/1462886671-3521-4-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes the checkpatch.pl warning "WARNING: space prohibited before
semicolon" at nilfs_store_magic_and_option().

Link: http://lkml.kernel.org/r/1462886671-3521-3-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This updates call sites of nilfs_warning() and nilfs_error() so that they
don't add a duplicate newline.  These output functions are already
designed to add a trailing newline to the message.

Link: http://lkml.kernel.org/r/1462886671-3521-2-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Remove trailing semicolons from macros, as suggested by checkpatch.pl.

Link: http://lkml.kernel.org/r/1461935747-10380-12-git-send-email-konishi.ryusuke@lab.ntt.co.jp
[konishi.ryusuke@lab.ntt.co.jp: fix style issues]
  Link: http://lkml.kernel.org/r/20160509.231703.1481729973362188932.konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Clean up checkpatch.pl warnings "WARNING: Missing a blank line after
declarations" from nilfs2.

Link: http://lkml.kernel.org/r/1461935747-10380-11-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This fixes the following checkpatch.pl warning:

  WARNING: __packed is preferred over __attribute__((packed))
  #23: FILE: export.h:23:
  +} __attribute__ ((packed));

Link: http://lkml.kernel.org/r/1461935747-10380-10-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Refactor nilfs_clear_inode() and nilfs_i_callback() so that cleanup
code or resource deallocation related to metadata file will be moved
out to mdt.c.

Link: http://lkml.kernel.org/r/1461935747-10380-9-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

nilfs_mdt_mark_block_dirty() can be replaced with primary functions
like nilfs_mdt_get_block() and mark_buffer_dirty(), and it's used only
by nilfs_ioctl_mark_blocks_dirty().

This gets rid of the function to simplify the interface of metadata
file.

Link: http://lkml.kernel.org/r/1461935747-10380-8-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

To respond to a certain developer's request, this explicitly state that
developers can reimplement the nilfs2 design for other operating systems
to share data stored in that format.

Link: http://lkml.kernel.org/r/1461935747-10380-7-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Add nilfs.osdn.jp as the second web site of nilfs project.

Link: http://lkml.kernel.org/r/1461935747-10380-6-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

E-mail addresses of osrg.net domain are no longer available.  This
removes them from authorship notices and prevents reporters from being
confused.

Link: http://lkml.kernel.org/r/1461935747-10380-5-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This removes the extra paragraph which mentions FSF address in GPL
notices from source code of nilfs2 and avoids the checkpatch.pl error
related to it.

Link: http://lkml.kernel.org/r/1461935747-10380-4-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix checkpatch.pl error "ERROR: space prohibited before that ','
(ctx:WxW)" at nilfs_sufile_set_suinfo().

This also fixes checkpatch.pl warning "WARNING: Prefer 'unsigned int' to
bare use of 'unsigned'" at nilfs_sufile_set_suinfo() and
nilfs_sufile_get_suinfo().

Link: http://lkml.kernel.org/r/1461935747-10380-3-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix the following checkpatch.pl error and warnings:

  ERROR: code indent should use tabs where possible
  #1317: FILE: super.c:1317:
  + ^I^Is_new = true;$

  WARNING: please, no space before tabs
  #1317: FILE: super.c:1317:
  + ^I^Is_new = true;$

  WARNING: please, no spaces at the start of a line
  #1317: FILE: super.c:1317:
  + ^I^Is_new = true;$

Link: http://lkml.kernel.org/r/1461935747-10380-2-git-send-email-konishi.ryusuke@lab.ntt.co.jpSigned-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The nilfs_sc_operations structures are never modified, so declare them
as const.

Done with the help of Coccinelle.
Signed-off-by: NJulia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bh is reinitialized by sb_bread() so no need to init it
with NULL in the beginning of befs_bread()

Link: http://lkml.kernel.org/r/88481760b43226fac16adb1f1e68897e47d8235c.1462841692.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bh is reinitialized by sb_bread() so no need to init it
with NULL in the beginning of befs_bread_iaddr()

Link: http://lkml.kernel.org/r/586d2639d729345b9c07aac10ba713d8ceb8745a.1462841692.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

befs_ino is reinitialized by BEFS_I() so no need to init it
with NULL in the beginning of befs_iget()

Link: http://lkml.kernel.org/r/a5c02445e436629c4d4ba1b65d91501878942f58.1462842887.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

raw_inode is reinitialized to bh->b_data so no need to init it
with NULL in the beginning of befs_iget()

Link: http://lkml.kernel.org/r/0a66baaaacb6b7e5fcea5b31b57b649261152281.1462842887.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bh is reinitialized by befs_bread() so no need to init it
with NULL in the beginning of befs_iget()

Link: http://lkml.kernel.org/r/38d62b1469bc3b316ba6b81fd8e26fc66fdd713b.1462842886.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

inode is reinitialized by befs_iget() so no need to init it
with NULL in the beginning of befs_lookup()

Link: http://lkml.kernel.org/r/03d7e46890aef94078130bed97c4f8f8ae9ea2b2.1462842886.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

iaddr_array is unconditionally initialized to NULL in
befs_find_brun_dblindirect().

Link: http://lkml.kernel.org/r/940def273e30ef37957fba9da6981a10fb3c9741.1462649034.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bh is reinitialized by befs_read_datastream() so no need to init it
with NULL in the beginning of befs_read_lsymlink().

Link: http://lkml.kernel.org/r/e22f279bceb8d026af048952e02ba98925b21c92.1462649034.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

bh is reinitialized by befs_bread_iaddr() so no need to init it
with NULL in the beginning of befs_read_datastream().

Link: http://lkml.kernel.org/r/81e1f70187db34d195c8e42b1ff78be6a71c0060.1462649034.git.salah.triki@acm.orgSigned-off-by: NSalah Triki <salah.triki@acm.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

mem_cgroup_oom may be invoked multiple times while a process is handling
a page fault, in which case current->memcg_in_oom will be overwritten
leaking the previously taken css reference.

Link: http://lkml.kernel.org/r/1464019330-7579-1-git-send-email-vdavydov@virtuozzo.comSigned-off-by: NVladimir Davydov <vdavydov@virtuozzo.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

CONFIG_MIPS32_N32=y but CONFIG_BINFMT_ELF disabled results in the
following linker errors:

  arch/mips/built-in.o: In function `elf_core_dump':
  binfmt_elfn32.c:(.text+0x23dbc): undefined reference to `elf_core_extra_phdrs'
  binfmt_elfn32.c:(.text+0x246e4): undefined reference to `elf_core_extra_data_size'
  binfmt_elfn32.c:(.text+0x248d0): undefined reference to `elf_core_write_extra_phdrs'
  binfmt_elfn32.c:(.text+0x24ac4): undefined reference to `elf_core_write_extra_data'

CONFIG_MIPS32_O32=y but CONFIG_BINFMT_ELF disabled results in the following
linker errors:

  arch/mips/built-in.o: In function `elf_core_dump':
  binfmt_elfo32.c:(.text+0x28a04): undefined reference to `elf_core_extra_phdrs'
  binfmt_elfo32.c:(.text+0x29330): undefined reference to `elf_core_extra_data_size'
  binfmt_elfo32.c:(.text+0x2951c): undefined reference to `elf_core_write_extra_phdrs'
  binfmt_elfo32.c:(.text+0x29710): undefined reference to `elf_core_write_extra_data'

This is because binfmt_elfn32 and binfmt_elfo32 are using symbols from
elfcore but for these configurations elfcore will not be built.

Fixed by making elfcore selectable by a separate config symbol which
unlike the current mechanism can also be used from other directories
than kernel/, then having each flavor of ELF that relies on elfcore.o,
select it in Kconfig, including CONFIG_MIPS32_N32 and CONFIG_MIPS32_O32
which fixes this issue.

Link: http://lkml.kernel.org/r/20160520141705.GA1913@linux-mips.orgSigned-off-by: NRalf Baechle <ralf@linux-mips.org>
Reviewed-by: NJames Hogan <james.hogan@imgtec.com>
Cc: "Maciej W. Rozycki" <macro@linux-mips.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

m32r allmodconfig build was failing with the error:

  ERROR: "smp_flush_cache_all" [drivers/misc/lkdtm.ko] undefined!

lkdtm driver at drivers/misc is using flush_icache_range() which for
m32r is defined as smp_flush_cache_all() if CONFIG_SMP is defined.  But
as smp_flush_cache_all() was not exported so the build was failing with
the error of undefined symbol.

Link: http://lkml.kernel.org/r/1464001182-8329-1-git-send-email-sudipm.mukherjee@gmail.comSigned-off-by: NSudip Mukherjee <sudip.mukherjee@codethink.co.uk>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Pull motr tracing updates from Steven Rostedt:
 "Three more changes.

   - I forgot that I had another selftest to stress test the ftrace
     instance creation.  It was actually suppose to go into the 4.6
     merge window, but I never committed it.  I almost forgot about it
     again, but noticed it was missing from your tree.

   - Soumya PN sent me a clean up patch to not disable interrupts when
     taking the tasklist_lock for read, as it's unnecessary because that
     lock is never taken for write in irq context.

   - Newer gcc's can cause the jump in the function_graph code to the
     global ftrace_stub label to be a short jump instead of a long one.
     As that jump is dynamically converted to jump to the trace code to
     do function graph tracing, and that conversion expects a long jump
     it can corrupt the ftrace_stub itself (it's directly after that
     call).  One way to prevent gcc from using a short jump is to
     declare the ftrace_stub as a weak function, which we do here to
     keep gcc from optimizing too much"

* tag 'trace-v4.7-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  ftrace/x86: Set ftrace_stub to weak to prevent gcc from using short jumps to it
  ftrace: Don't disable irqs when taking the tasklist_lock read_lock
  ftracetest: Add instance created, delete, read and enable event test