linux-stable.git/include/linux/mm_types.h, branch v5.0.4

mm: introduce common STRUCT_PAGE_MAX_SHIFT define

2018-12-14T23:05:45+00:00

This define is used by arm64 to calculate the size of the vmemmap
region.  It is defined as the log2 of the upper bound on the size of a
struct page.

We move it into mm_types.h so it can be defined properly instead of set
and checked with a build bug.  This also allows us to use the same
define for riscv.

Link: http://lkml.kernel.org/r/20181107205433.3875-2-logang@deltatee.com
Signed-off-by: Logan Gunthorpe 
Acked-by: Will Deacon 
Acked-by: Andrew Morton 
Acked-by: Ard Biesheuvel 
Acked-by: Catalin Marinas 
Cc: Arnd Bergmann 
Cc: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: get rid of vmacache_flush_all() entirely

2018-09-14T01:18:04+00:00

Jann Horn points out that the vmacache_flush_all() function is not only
potentially expensive, it's buggy too.  It also happens to be entirely
unnecessary, because the sequence number overflow case can be avoided by
simply making the sequence number be 64-bit.  That doesn't even grow the
data structures in question, because the other adjacent fields are
already 64-bit.

So simplify the whole thing by just making the sequence number overflow
case go away entirely, which gets rid of all the complications and makes
the code faster too.  Win-win.

[ Oleg Nesterov points out that the VMACACHE_FULL_FLUSHES statistics
  also just goes away entirely with this ]

Reported-by: Jann Horn 
Suggested-by: Will Deacon 
Acked-by: Davidlohr Bueso 
Cc: Oleg Nesterov 
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds

Merge tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2018-08-17T18:32:50+00:00

Pull powerpc updates from Michael Ellerman:
 "Notable changes:

   - A fix for a bug in our page table fragment allocator, where a page
     table page could be freed and reallocated for something else while
     still in use, leading to memory corruption etc. The fix reuses
     pt_mm in struct page (x86 only) for a powerpc only refcount.

   - Fixes to our pkey support. Several are user-visible changes, but
     bring us in to line with x86 behaviour and/or fix outright bugs.
     Thanks to Florian Weimer for reporting many of these.

   - A series to improve the hvc driver & related OPAL console code,
     which have been seen to cause hardlockups at times. The hvc driver
     changes in particular have been in linux-next for ~month.

   - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y.

   - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in
     use anywhere other than as a paper weight.

   - An optimised memcmp implementation using Power7-or-later VMX
     instructions

   - Support for barrier_nospec on some NXP CPUs.

   - Support for flushing the count cache on context switch on some IBM
     CPUs (controlled by firmware), as a Spectre v2 mitigation.

   - A series to enhance the information we print on unhandled signals
     to bring it into line with other arches, including showing the
     offending VMA and dumping the instructions around the fault.

  Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey
  Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan,
  Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski,
  Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng,
  Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph
  Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave
  Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer,
  Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand,
  Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel
  Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh
  Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues,
  Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha,
  Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul
  Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza
  Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood,
  Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago
  Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat
  Rao, zhong jiang"

* tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits)
  powerpc/mm/book3s/radix: Add mapping statistics
  powerpc/uaccess: Enable get_user(u64, *p) on 32-bit
  powerpc/mm/hash: Remove unnecessary do { } while(0) loop
  powerpc/64s: move machine check SLB flushing to mm/slb.c
  powerpc/powernv/idle: Fix build error
  powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range
  powerpc/mm: remove warning about ‘type’ being set
  powerpc/32: Include setup.h header file to fix warnings
  powerpc: Move `path` variable inside DEBUG_PROM
  powerpc/powermac: Make some functions static
  powerpc/powermac: Remove variable x that's never read
  cxl: remove a dead branch
  powerpc/powermac: Add missing include of header pmac.h
  powerpc/kexec: Use common error handling code in setup_new_fdt()
  powerpc/xmon: Add address lookup for percpu symbols
  powerpc/mm: remove huge_pte_offset_and_shift() prototype
  powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled
  powerpc/pseries: Fix endianness while restoring of r3 in MCE handler.
  powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements
  powerpc/fadump: handle crash memory ranges array index overflow
  ...

powerpc/64s: Fix page table fragment refcount race vs speculative references

2018-08-07T14:32:32+00:00

The page table fragment allocator uses the main page refcount racily
with respect to speculative references. A customer observed a BUG due
to page table page refcount underflow in the fragment allocator. This
can be caused by the fragment allocator set_page_count stomping on a
speculative reference, and then the speculative failure handler
decrements the new reference, and the underflow eventually pops when
the page tables are freed.

Fix this by using a dedicated field in the struct page for the page
table fragment allocator.

Fixes: 5c1f6ee9a31c ("powerpc: Reduce PTE table memory wastage")
Cc: stable@vger.kernel.org # v3.10+
Reviewed-by: Aneesh Kumar K.V 
Signed-off-by: Nicholas Piggin 
Signed-off-by: Michael Ellerman

mm: Allocate the mm_cpumask (mm->cpu_bitmap[]) dynamically based on nr_cpu_ids

2018-07-17T07:35:30+00:00

The mm_struct always contains a cpumask bitmap, regardless of
CONFIG_CPUMASK_OFFSTACK. That means the first step can be to
simplify things, and simply have one bitmask at the end of the
mm_struct for the mm_cpumask.

This does necessitate moving everything else in mm_struct into
an anonymous sub-structure, which can be randomized when struct
randomization is enabled.

The second step is to determine the correct size for the
mm_struct slab object from the size of the mm_struct
(excluding the CPU bitmap) and the size the cpumask.

For init_mm we can simply allocate the maximum size this
kernel is compiled for, since we only have one init_mm
in the system, anyway.

Pointer magic by Mike Galbraith, to evade -Wstringop-overflow
getting confused by the dynamically sized array.

Tested-by: Song Liu 
Signed-off-by: Rik van Riel 
Signed-off-by: Mike Galbraith 
Signed-off-by: Rik van Riel 
Acked-by: Dave Hansen 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: kernel-team@fb.com
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20180716190337.26133-2-riel@surriel.com
Signed-off-by: Ingo Molnar

mm: add hmm_data to struct page

2018-06-08T00:34:37+00:00

Make hmm_data an explicit member of the struct page union.

Link: http://lkml.kernel.org/r/20180518194519.3820-14-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: "Kirill A . Shutemov" 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: add pt_mm to struct page

2018-06-08T00:34:37+00:00

For pgd page table pages, x86 overloads the page->index field to store a
pointer to the mm_struct.  Rename this to pt_mm so it's visible to other
users.

Link: http://lkml.kernel.org/r/20180518194519.3820-13-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: "Kirill A . Shutemov" 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: improve struct page documentation

2018-06-08T00:34:37+00:00

Rewrite the documentation to describe what you can use in struct page
rather than what you can't.

Link: http://lkml.kernel.org/r/20180518194519.3820-12-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Reviewed-by: Randy Dunlap 
Acked-by: Vlastimil Babka 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: "Kirill A . Shutemov" 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: combine LRU and main union in struct page

2018-06-08T00:34:37+00:00

This gives us five words of space in a single union in struct page.  The
compound_mapcount moves position (from offset 24 to offset 20) on 64-bit
systems, but that does not seem likely to cause any trouble.

Link: http://lkml.kernel.org/r/20180518194519.3820-11-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Acked-by: Kirill A. Shutemov 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: move lru union within struct page

2018-06-08T00:34:37+00:00

Since the LRU is two words, this does not affect the double-word alignment
of SLUB's freelist.

Link: http://lkml.kernel.org/r/20180518194519.3820-10-willy@infradead.org
Signed-off-by: Matthew Wilcox 
Acked-by: Vlastimil Babka 
Acked-by: Kirill A. Shutemov 
Cc: Christoph Lameter 
Cc: Dave Hansen 
Cc: Jérôme Glisse 
Cc: Lai Jiangshan 
Cc: Martin Schwidefsky 
Cc: Pekka Enberg 
Cc: Randy Dunlap 
Cc: Andrey Ryabinin 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds