linux.git/mm/util.c, branch v5.8

mmap locking API: convert mmap_sem comments

2020-06-09T16:39:14+00:00

Convert comments that reference mmap_sem to reference mmap_lock instead.

[akpm@linux-foundation.org: fix up linux-next leftovers]
[akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil]
[akpm@linux-foundation.org: more linux-next fixups, per Michel]

Signed-off-by: Michel Lespinasse 
Signed-off-by: Andrew Morton 
Reviewed-by: Vlastimil Babka 
Reviewed-by: Daniel Jordan 
Cc: Davidlohr Bueso 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jason Gunthorpe 
Cc: Jerome Glisse 
Cc: John Hubbard 
Cc: Laurent Dufour 
Cc: Liam Howlett 
Cc: Matthew Wilcox 
Cc: Peter Zijlstra 
Cc: Ying Han 
Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com
Signed-off-by: Linus Torvalds

mmap locking API: add mmap_assert_locked() and mmap_assert_write_locked()

2020-06-09T16:39:14+00:00

Add new APIs to assert that mmap_sem is held.

Using this instead of rwsem_is_locked and lockdep_assert_held[_write]
makes the assertions more tolerant of future changes to the lock type.

Signed-off-by: Michel Lespinasse 
Signed-off-by: Andrew Morton 
Reviewed-by: Vlastimil Babka 
Reviewed-by: Daniel Jordan 
Cc: Davidlohr Bueso 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jason Gunthorpe 
Cc: Jerome Glisse 
Cc: John Hubbard 
Cc: Laurent Dufour 
Cc: Liam Howlett 
Cc: Matthew Wilcox 
Cc: Peter Zijlstra 
Cc: Ying Han 
Link: http://lkml.kernel.org/r/20200520052908.204642-10-walken@google.com
Signed-off-by: Linus Torvalds

mmap locking API: use coccinelle to convert mmap_sem rwsem call sites

2020-06-09T16:39:14+00:00

This change converts the existing mmap_sem rwsem calls to use the new mmap
locking API instead.

The change is generated using coccinelle with the following rule:

// spatch --sp-file mmap_lock_api.cocci --in-place --include-headers --dir .

@@
expression mm;
@@
(
-init_rwsem
+mmap_init_lock
|
-down_write
+mmap_write_lock
|
-down_write_killable
+mmap_write_lock_killable
|
-down_write_trylock
+mmap_write_trylock
|
-up_write
+mmap_write_unlock
|
-downgrade_write
+mmap_write_downgrade
|
-down_read
+mmap_read_lock
|
-down_read_killable
+mmap_read_lock_killable
|
-down_read_trylock
+mmap_read_trylock
|
-up_read
+mmap_read_unlock
)
-(&mm->mmap_sem)
+(mm)

Signed-off-by: Michel Lespinasse 
Signed-off-by: Andrew Morton 
Reviewed-by: Daniel Jordan 
Reviewed-by: Laurent Dufour 
Reviewed-by: Vlastimil Babka 
Cc: Davidlohr Bueso 
Cc: David Rientjes 
Cc: Hugh Dickins 
Cc: Jason Gunthorpe 
Cc: Jerome Glisse 
Cc: John Hubbard 
Cc: Liam Howlett 
Cc: Matthew Wilcox 
Cc: Peter Zijlstra 
Cc: Ying Han 
Link: http://lkml.kernel.org/r/20200520052908.204642-5-walken@google.com
Signed-off-by: Linus Torvalds

mm: add kvfree_sensitive() for freeing sensitive data objects

2020-06-05T02:06:22+00:00

For kvmalloc'ed data object that contains sensitive information like
cryptographic keys, we need to make sure that the buffer is always cleared
before freeing it.  Using memset() alone for buffer clearing may not
provide certainty as the compiler may compile it away.  To be sure, the
special memzero_explicit() has to be used.

This patch introduces a new kvfree_sensitive() for freeing those sensitive
data objects allocated by kvmalloc().  The relevant places where
kvfree_sensitive() can be used are modified to use it.

Fixes: 4f0882491a14 ("KEYS: Avoid false positive ENOMEM error on key read")
Suggested-by: Linus Torvalds 
Signed-off-by: Waiman Long 
Signed-off-by: Andrew Morton 
Reviewed-by: Eric Biggers 
Acked-by: David Howells 
Cc: Jarkko Sakkinen 
Cc: James Morris 
Cc: "Serge E. Hallyn" 
Cc: Joe Perches 
Cc: Matthew Wilcox 
Cc: David Rientjes 
Cc: Uladzislau Rezki 
Link: http://lkml.kernel.org/r/20200407200318.11711-1-longman@redhat.com
Signed-off-by: Linus Torvalds

mm/util.c: remove the VM_WARN_ONCE for vm_committed_as underflow check

2020-06-05T02:06:20+00:00

This check was added by commit 82f71ae4a2b8 ("mm: catch memory
commitment underflow") in 2014 to have a safety check for issues which
have been fixed.  And there has been few report caught by it, as
described in its commit log:

: This shouldn't happen any more - the previous two patches fixed
: the committed_as underflow issues.

But it was really found by Qian Cai when he used the LTP memory stress
suite to test a RFC patchset, which tries to improve scalability of
per-cpu counter 'vm_committed_as', by chosing a bigger 'batch' number for
loose overcommit policies (OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS), while
keeping current number for OVERCOMMIT_NEVER.

With that patchset, when system firstly uses a loose policy, the
'vm_committed_as' count could be a big negative value, as its big 'batch'
number allows a big deviation, then when the policy is changed to
OVERCOMMIT_NEVER, the 'batch' will be decreased to a much smaller value,
thus hits this WARN check.

To mitigate this, one proposed solution is to queue work on all online
CPUs to do a local sync for 'vm_committed_as' when changing policy to
OVERCOMMIT_NEVER, plus some global syncing to garante the case won't be
hit.

But this solution is costy and slow, given this check hasn't shown real
trouble or benefit, simply drop it from one hot path of MM.  And perf
stats does show some tiny saving for removing it.

Reported-by: Qian Cai 
Signed-off-by: Feng Tang 
Signed-off-by: Andrew Morton 
Reviewed-by: Qian Cai 
Acked-by: Michal Hocko 
Cc: Konstantin Khlebnikov 
Cc: Andi Kleen 
Cc: Johannes Weiner 
Cc: Matthew Wilcox 
Cc: Mel Gorman 
Cc: Kees Cook 
Link: http://lkml.kernel.org/r/20200603094804.GB89848@shbuild999.sh.intel.com
Signed-off-by: Linus Torvalds

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next

2020-06-03T23:27:18+00:00

Pull networking updates from David Miller:

 1) Allow setting bluetooth L2CAP modes via socket option, from Luiz
    Augusto von Dentz.

 2) Add GSO partial support to igc, from Sasha Neftin.

 3) Several cleanups and improvements to r8169 from Heiner Kallweit.

 4) Add IF_OPER_TESTING link state and use it when ethtool triggers a
    device self-test. From Andrew Lunn.

 5) Start moving away from custom driver versions, use the globally
    defined kernel version instead, from Leon Romanovsky.

 6) Support GRO vis gro_cells in DSA layer, from Alexander Lobakin.

 7) Allow hard IRQ deferral during NAPI, from Eric Dumazet.

 8) Add sriov and vf support to hinic, from Luo bin.

 9) Support Media Redundancy Protocol (MRP) in the bridging code, from
    Horatiu Vultur.

10) Support netmap in the nft_nat code, from Pablo Neira Ayuso.

11) Allow UDPv6 encapsulation of ESP in the ipsec code, from Sabrina
    Dubroca. Also add ipv6 support for espintcp.

12) Lots of ReST conversions of the networking documentation, from Mauro
    Carvalho Chehab.

13) Support configuration of ethtool rxnfc flows in bcmgenet driver,
    from Doug Berger.

14) Allow to dump cgroup id and filter by it in inet_diag code, from
    Dmitry Yakunin.

15) Add infrastructure to export netlink attribute policies to
    userspace, from Johannes Berg.

16) Several optimizations to sch_fq scheduler, from Eric Dumazet.

17) Fallback to the default qdisc if qdisc init fails because otherwise
    a packet scheduler init failure will make a device inoperative. From
    Jesper Dangaard Brouer.

18) Several RISCV bpf jit optimizations, from Luke Nelson.

19) Correct the return type of the ->ndo_start_xmit() method in several
    drivers, it's netdev_tx_t but many drivers were using
    'int'. From Yunjian Wang.

20) Add an ethtool interface for PHY master/slave config, from Oleksij
    Rempel.

21) Add BPF iterators, from Yonghang Song.

22) Add cable test infrastructure, including ethool interfaces, from
    Andrew Lunn. Marvell PHY driver is the first to support this
    facility.

23) Remove zero-length arrays all over, from Gustavo A. R. Silva.

24) Calculate and maintain an explicit frame size in XDP, from Jesper
    Dangaard Brouer.

25) Add CAP_BPF, from Alexei Starovoitov.

26) Support terse dumps in the packet scheduler, from Vlad Buslov.

27) Support XDP_TX bulking in dpaa2 driver, from Ioana Ciornei.

28) Add devm_register_netdev(), from Bartosz Golaszewski.

29) Minimize qdisc resets, from Cong Wang.

30) Get rid of kernel_getsockopt and kernel_setsockopt in order to
    eliminate set_fs/get_fs calls. From Christoph Hellwig.

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (2517 commits)
  selftests: net: ip_defrag: ignore EPERM
  net_failover: fixed rollback in net_failover_open()
  Revert "tipc: Fix potential tipc_aead refcnt leak in tipc_crypto_rcv"
  Revert "tipc: Fix potential tipc_node refcnt leak in tipc_rcv"
  vmxnet3: allow rx flow hash ops only when rss is enabled
  hinic: add set_channels ethtool_ops support
  selftests/bpf: Add a default $(CXX) value
  tools/bpf: Don't use $(COMPILE.c)
  bpf, selftests: Use bpf_probe_read_kernel
  s390/bpf: Use bcr 0,%0 as tail call nop filler
  s390/bpf: Maintain 8-byte stack alignment
  selftests/bpf: Fix verifier test
  selftests/bpf: Fix sample_cnt shared between two threads
  bpf, selftests: Adapt cls_redirect to call csum_level helper
  bpf: Add csum_level helper for fixing up csum levels
  bpf: Fix up bpf_skb_adjust_room helper's skb csum setting
  sfc: add missing annotation for efx_ef10_try_update_nic_stats_vf()
  crypto/chtls: IPv6 support for inline TLS
  Crypto/chcr: Fixes a coccinile check error
  Crypto/chcr: Fixes compilations warnings
  ...

mm: remove __vmalloc_node_flags_caller

2020-06-02T17:59:11+00:00

Just use __vmalloc_node instead which gets and extra argument.  To be able
to to use __vmalloc_node in all caller make it available outside of
vmalloc and implement it in nommu.c.

[akpm@linux-foundation.org: fix nommu build]
Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Acked-by: Peter Zijlstra (Intel) 
Cc: Christian Borntraeger 
Cc: Christophe Leroy 
Cc: Daniel Vetter 
Cc: David Airlie 
Cc: Gao Xiang 
Cc: Greg Kroah-Hartman 
Cc: Haiyang Zhang 
Cc: Johannes Weiner 
Cc: "K. Y. Srinivasan" 
Cc: Laura Abbott 
Cc: Mark Rutland 
Cc: Michael Kelley 
Cc: Minchan Kim 
Cc: Nitin Gupta 
Cc: Robin Murphy 
Cc: Sakari Ailus 
Cc: Stephen Hemminger 
Cc: Sumit Semwal 
Cc: Wei Liu 
Cc: Benjamin Herrenschmidt 
Cc: Catalin Marinas 
Cc: Heiko Carstens 
Cc: Paul Mackerras 
Cc: Vasily Gorbik 
Cc: Will Deacon 
Cc: Stephen Rothwell 
Link: http://lkml.kernel.org/r/20200414131348.444715-25-hch@lst.de
Signed-off-by: Linus Torvalds

sysctl: pass kernel pointers to ->proc_handler

2020-04-27T06:07:40+00:00

Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig 
Acked-by: Andrey Ignatov 
Signed-off-by: Al Viro

mm/mmap.c: rb_parent is not necessary in __vma_link_list()

2019-12-01T14:29:19+00:00

Now we use rb_parent to get next, while this is not necessary.

When prev is NULL, this means vma should be the first element in the list.
Then next should be current first one (mm->mmap), no matter whether we
have parent or not.

After removing it, the code shows the beauty of symmetry.

Link: http://lkml.kernel.org/r/20190813032656.16625-1-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang 
Acked-by: Andrew Morton 
Cc: Mel Gorman 
Cc: Vlastimil Babka 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm/mmap.c: extract __vma_unlink_list() as counterpart for __vma_link_list()

2019-12-01T14:29:19+00:00

Just make the code a little easier to read.

Link: http://lkml.kernel.org/r/20191006012636.31521-3-richardw.yang@linux.intel.com
Signed-off-by: Wei Yang 
Cc: Christoph Hellwig 
Cc: Matthew Wilcox (Oracle) 
Cc: Mel Gorman 
Cc: Oscar Salvador 
Cc: Vlastimil Babka 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds