linux-stable.git/include/linux/mm_types.h, branch v4.11.2

mm/headers, sched/headers: Move task related MM types from to

2017-03-03T00:43:48+00:00

Separate all the MM types that are embedded directly in 'struct task_struct'
into the  header.

The goal is to include this header in , not the full 
header, to reduce the size, complexity and coupling of .

(This patch does not change  yet.)

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

sched/headers: Move the 'init_mm' declaration from to

2017-03-03T00:43:39+00:00

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

mm/headers, sched/headers: Prepare to split out of

2017-03-02T07:42:37+00:00

We are going to separate all the MM types that are embedded directly in 'struct task_struct'
into the new  header.

Create a new  that only contains some includes from mm_types.h itself.

This should be trivially correct and easy to bisect to.

(This patch does not materially move the types yet.)

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

mm/vmacache, sched/headers: Introduce 'struct vmacache' and move it from to

2017-03-02T07:42:25+00:00

The  header includes various vmacache related defines,
which are arguably misplaced.

Move them to mm_types.h and minimize the sched.h impact by putting
all task vmacache state into a new 'struct vmacache' structure.

No change in functionality.

Acked-by: Linus Torvalds 
Cc: Mike Galbraith 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar

mm: clarify mm_struct.mm_{users,count} documentation

2017-02-28T02:43:48+00:00

Clarify documentation relating to mm_users and mm_count, and switch to
kernel-doc syntax.

Link: http://lkml.kernel.org/r/20161218123229.22952-4-vegard.nossum@oracle.com
Signed-off-by: Vegard Nossum 
Acked-by: Michal Hocko 
Acked-by: Peter Zijlstra (Intel) 
Acked-by: David Rientjes 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

2016-12-18T19:12:53+00:00

Pull x86 fixes and cleanups from Thomas Gleixner:
 "This set of updates contains:

   - Robustification for the logical package managment. Cures the AMD
     and virtualization issues.

   - Put the correct start_cpu() return address on the stack of the idle
     task.

   - Fixups for the fallout of the nodeid <-> cpuid persistent mapping
     modifciations

   - Move the x86/MPX specific mm_struct member to the arch specific
     mm_context where it belongs

   - Cleanups for C89 struct initializers and useless function
     arguments"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/floppy: Use designated initializers
  x86/mpx: Move bd_addr to mm_context_t
  x86/mm: Drop unused argument 'removed' from sync_global_pgds()
  ACPI/NUMA: Do not map pxm to node when NUMA is turned off
  x86/acpi: Use proper macro for invalid node
  x86/smpboot: Prevent false positive out of bounds cpumask access warning
  x86/boot/64: Push correct start_cpu() return address
  x86/boot/64: Use 'push' instead of 'call' in start_cpu()
  x86/smpboot: Make logical package management more robust

x86/mpx: Move bd_addr to mm_context_t

2016-12-17T11:29:56+00:00

Currently bd_addr lives in mm_struct, which is otherwise architecture
independent. Architecture-specific data is supposed to live within
mm_context_t (itself contained in mm_struct).

Other x86-specific context like the pkey accounting data lives in
mm_context_t, and there's no readon the MPX data can't also live there.
So as to keep the arch-specific data togather, and to set a good example
for others, this patch moves bd_addr into x86's mm_context_t.

Signed-off-by: Mark Rutland 
Acked-by: Dave Hansen 
Cc: Andrew Morton 
Link: http://lkml.kernel.org/r/1481892055-24596-1-git-send-email-mark.rutland@arm.com
Signed-off-by: Thomas Gleixner

mm: Add a user_ns owner to mm_struct and fix ptrace permission checks

2016-11-22T17:49:48+00:00

During exec dumpable is cleared if the file that is being executed is
not readable by the user executing the file.  A bug in
ptrace_may_access allows reading the file if the executable happens to
enter into a subordinate user namespace (aka clone(CLONE_NEWUSER),
unshare(CLONE_NEWUSER), or setns(fd, CLONE_NEWUSER).

This problem is fixed with only necessary userspace breakage by adding
a user namespace owner to mm_struct, captured at the time of exec, so
it is clear in which user namespace CAP_SYS_PTRACE must be present in
to be able to safely give read permission to the executable.

The function ptrace_may_access is modified to verify that the ptracer
has CAP_SYS_ADMIN in task->mm->user_ns instead of task->cred->user_ns.
This ensures that if the task changes it's cred into a subordinate
user namespace it does not become ptraceable.

The function ptrace_attach is modified to only set PT_PTRACE_CAP when
CAP_SYS_PTRACE is held over task->mm->user_ns.  The intent of
PT_PTRACE_CAP is to be a flag to note that whatever permission changes
the task might go through the tracer has sufficient permissions for
it not to be an issue.  task->cred->user_ns is always the same
as or descendent of mm->user_ns.  Which guarantees that having
CAP_SYS_PTRACE over mm->user_ns is the worst case for the tasks
credentials.

To prevent regressions mm->dumpable and mm->user_ns are not considered
when a task has no mm.  As simply failing ptrace_may_attach causes
regressions in privileged applications attempting to read things
such as /proc//stat

Cc: stable@vger.kernel.org
Acked-by: Kees Cook 
Tested-by: Cyrill Gorcunov 
Fixes: 8409cca70561 ("userns: allow ptrace from non-init user namespaces")
Signed-off-by: "Eric W. Biederman"

kernel, oom: fix potential pgd_lock deadlock from __mmdrop

2016-10-08T01:46:27+00:00

Lockdep complains that __mmdrop is not safe from the softirq context:

  =================================
  [ INFO: inconsistent lock state ]
  4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949 Tainted: G        W
  ---------------------------------
  inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
  swapper/1/0 [HC0[0]:SC1[1]:HE1:SE0] takes:
   (pgd_lock){+.?...}, at: pgd_free+0x19/0x6b
  {SOFTIRQ-ON-W} state was registered at:
     __lock_acquire+0xa06/0x196e
     lock_acquire+0x139/0x1e1
     _raw_spin_lock+0x32/0x41
     __change_page_attr_set_clr+0x2a5/0xacd
     change_page_attr_set_clr+0x16f/0x32c
     set_memory_nx+0x37/0x3a
     free_init_pages+0x9e/0xc7
     alternative_instructions+0xa2/0xb3
     check_bugs+0xe/0x2d
     start_kernel+0x3ce/0x3ea
     x86_64_start_reservations+0x2a/0x2c
     x86_64_start_kernel+0x17a/0x18d
  irq event stamp: 105916
  hardirqs last  enabled at (105916): free_hot_cold_page+0x37e/0x390
  hardirqs last disabled at (105915): free_hot_cold_page+0x2c1/0x390
  softirqs last  enabled at (105878): _local_bh_enable+0x42/0x44
  softirqs last disabled at (105879): irq_exit+0x6f/0xd1

  other info that might help us debug this:
   Possible unsafe locking scenario:

         CPU0
         ----
    lock(pgd_lock);
    
      lock(pgd_lock);

   *** DEADLOCK ***

  1 lock held by swapper/1/0:
   #0:  (rcu_callback){......}, at: rcu_process_callbacks+0x390/0x800

  stack backtrace:
  CPU: 1 PID: 0 Comm: swapper/1 Tainted: G        W       4.6.0-oomfortification2-00011-geeb3eadeab96-dirty #949
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Debian-1.8.2-1 04/01/2014
  Call Trace:
   
    print_usage_bug.part.25+0x259/0x268
    mark_lock+0x381/0x567
    __lock_acquire+0x993/0x196e
    lock_acquire+0x139/0x1e1
    _raw_spin_lock+0x32/0x41
    pgd_free+0x19/0x6b
    __mmdrop+0x25/0xb9
    __put_task_struct+0x103/0x11e
    delayed_put_task_struct+0x157/0x15e
    rcu_process_callbacks+0x660/0x800
    __do_softirq+0x1ec/0x4d5
    irq_exit+0x6f/0xd1
    smp_apic_timer_interrupt+0x42/0x4d
    apic_timer_interrupt+0x8e/0xa0
   
    arch_cpu_idle+0xf/0x11
    default_idle_call+0x32/0x34
    cpu_startup_entry+0x20c/0x399
    start_secondary+0xfe/0x101

More over commit a79e53d85683 ("x86/mm: Fix pgd_lock deadlock") was
explicit about pgd_lock not to be called from the irq context.  This
means that __mmdrop called from free_signal_struct has to be postponed
to a user context.  We already have a similar mechanism for mmput_async
so we can use it here as well.  This is safe because mm_count is pinned
by mm_users.

This fixes bug introduced by "oom: keep mm of the killed task available"

Link: http://lkml.kernel.org/r/1472119394-11342-5-git-send-email-mhocko@kernel.org
Signed-off-by: Michal Hocko 
Cc: Tetsuo Handa 
Cc: Oleg Nesterov 
Cc: David Rientjes 
Cc: Vladimir Davydov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm, vmscan: move lru_lock to the node

2016-07-28T23:07:41+00:00

Node-based reclaim requires node-based LRUs and locking.  This is a
preparation patch that just moves the lru_lock to the node so later
patches are easier to review.  It is a mechanical change but note this
patch makes contention worse because the LRU lock is hotter and direct
reclaim and kswapd can contend on the same lock even when reclaiming
from different zones.

Link: http://lkml.kernel.org/r/1467970510-21195-3-git-send-email-mgorman@techsingularity.net
Signed-off-by: Mel Gorman 
Reviewed-by: Minchan Kim 
Acked-by: Johannes Weiner 
Acked-by: Vlastimil Babka 
Cc: Hillf Danton 
Cc: Joonsoo Kim 
Cc: Michal Hocko 
Cc: Rik van Riel 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds