Very similar to VM_BUG_ON_PAGE and VM_BUG_ON_VMA, dump struct_mm when the
bug is hit.

[akpm@linux-foundation.org: coding-style fixes]
[mhocko@suse.cz: fix build]
[mhocko@suse.cz: fix build some more]
[akpm@linux-foundation.org: do strange things to avoid doing strange things for the comma separators]
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Cc: Dave Jones <davej@redhat.com>
Signed-off-by: NMichal Hocko <mhocko@suse.cz>
Cc: Valdis Kletnieks <Valdis.Kletnieks@vt.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Very similar to VM_BUG_ON_PAGE but dumps VMA information instead.
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Introduce a helper to dump information about a VMA, this also makes
dump_page_flags more generic and re-uses that so the output looks very
similar to dump_page:

[   61.903437] vma ffff88070f88be00 start 00007fff25970000 end 00007fff25992000
[   61.903437] next ffff88070facd600 prev ffff88070face400 mm ffff88070fade000
[   61.903437] prot 8000000000000025 anon_vma ffff88070fa1e200 vm_ops           (null)
[   61.903437] pgoff 7ffffffdd file           (null) private_data           (null)
[   61.909129] flags: 0x100173(read|write|mayread|maywrite|mayexec|growsdown|account)

[akpm@linux-foundation.org: make dump_vma() require CONFIG_DEBUG_VM]
[swarren@nvidia.com: fix dump_vma() compilation]
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Reviewed-by: NNaoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Hugh Dickins <hughd@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michel Lespinasse <walken@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

It was missing...

Cc: Konstantin Khlebnikov <koct9i@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
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 recently added a patch to let folks pass a "reason" string dump_page()
which gets dumped out along with the page's data.  This essentially
saves the bug-reader a trip in to the source to figure out why we
BUG_ON()'d.

The new VM_BUG_ON_PAGE() passes in NULL for "reason".  It seems like we
might as well pass the BUG_ON() condition if we have it.  This will
bloat kernels a bit with ~160 new strings, but this is all under a
debugging option anyway.

	page:ffffea0008560280 count:1 mapcount:0 mapping:(null) index:0x0
	page flags: 0xbfffc0000000001(locked)
	page dumped because: VM_BUG_ON_PAGE(PageLocked(page))
	------------[ cut here ]------------
	kernel BUG at /home/davehans/linux.git/mm/filemap.c:464!
	invalid opcode: 0000 [#1] SMP
	CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #251
	Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
	...

[akpm@linux-foundation.org: include stringify.h]
Signed-off-by: NDave Hansen <dave.hansen@linux.intel.com>
Acked-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NDavidlohr Bueso <davidlohr@hp.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

WARN_ON() and WARN_ON_ONCE(), dependent on CONFIG_DEBUG_VM

Cc: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

I tried to use 'dump_page(page, __func__)' for debugging, but it triggers
warning:

  warning: passing argument 2 of `dump_page' discards `const' qualifier from pointer target type [enabled by default]

Let's convert 'reason' to 'const char *' in dump_page() and friends: we
shouldn't modify it anyway.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Most of the VM_BUG_ON assertions are performed on a page.  Usually, when
one of these assertions fails we'll get a BUG_ON with a call stack and
the registers.

I've recently noticed based on the requests to add a small piece of code
that dumps the page to various VM_BUG_ON sites that the page dump is
quite useful to people debugging issues in mm.

This patch adds a VM_BUG_ON_PAGE(cond, page) which beyond doing what
VM_BUG_ON() does, also dumps the page before executing the actual
BUG_ON.

[akpm@linux-foundation.org: fix up includes]
Signed-off-by: NSasha Levin <sasha.levin@oracle.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Even if CONFIG_DEBUG_VM=n gcc genereates code for some VM_BUG_ON()

for example VM_BUG_ON(!PageCompound(page) || !PageHead(page)); in
do_huge_pmd_wp_page() generates 114 bytes of code.

But they mostly disappears when I split this VM_BUG_ON into two:

  -VM_BUG_ON(!PageCompound(page) || !PageHead(page));
  +VM_BUG_ON(!PageCompound(page));
  +VM_BUG_ON(!PageHead(page));

weird... but anyway after this patch code disappears completely.

  add/remove: 0/0 grow/shrink: 7/97 up/down: 135/-1784 (-1649)
Signed-off-by: NKonstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No real bugs, just some dead code and some fixups.
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

kbuild.h forces include of autoconf.h on the
commandline using -include - so we do not need to
include the file explicit.
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>
Signed-off-by: NMichal Marek <mmarek@suse.cz>

Signed-off-by: NIngo Molnar <mingo@elte.hu>

Add some (configurable) expensive sanity checking to catch wrong address
translations on x86.

- create linux/mmdebug.h file to be able include this file in
  asm headers to not get unsolvable loops in header files
- __phys_addr on x86_32 became a function in ioremap.c since
  PAGE_OFFSET, is_vmalloc_addr and VMALLOC_* non-constasts are undefined
  if declared in page_32.h
- add __phys_addr_const for initializing doublefault_tss.__cr3

Tested on 386, 386pae, x86_64 and x86_64 numa=fake=2.

Contains Andi's enable numa virtual address debug patch.
Signed-off-by: NJiri Slaby <jirislaby@gmail.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: NIngo Molnar <mingo@elte.hu>