17 Oct, 2020
1 commit
-
Memory allocated with kstrdup_const() must not be passed to regular
krealloc() as it is not aware of the possibility of the chunk residing in
.rodata. Since there are no potential users of krealloc_const() at the
moment, let's just update the doc to make it explicit.Signed-off-by: Bartosz Golaszewski
Signed-off-by: Andrew Morton
Reviewed-by: Andrew Morton
Link: http://lkml.kernel.org/r/20200817173927.23389-1-brgl@bgdev.pl
Signed-off-by: Linus Torvalds
04 Sep, 2020
1 commit
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When the Memory Tagging Extension is enabled, two pages are identical
only if both their data and tags are identical.Make the generic memcmp_pages() a __weak function and add an
arm64-specific implementation which returns non-zero if any of the two
pages contain valid MTE tags (PG_mte_tagged set). There isn't much
benefit in comparing the tags of two pages since these are normally used
for heap allocations and likely to differ anyway.Co-developed-by: Vincenzo Frascino
Signed-off-by: Vincenzo Frascino
Signed-off-by: Catalin Marinas
Cc: Will Deacon
08 Aug, 2020
3 commits
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The current split between do_mmap() and do_mmap_pgoff() was introduced in
commit 1fcfd8db7f82 ("mm, mpx: add "vm_flags_t vm_flags" arg to
do_mmap_pgoff()") to support MPX.The wrapper function do_mmap_pgoff() always passed 0 as the value of the
vm_flags argument to do_mmap(). However, MPX support has subsequently
been removed from the kernel and there were no more direct callers of
do_mmap(); all calls were going via do_mmap_pgoff().Simplify the code by removing do_mmap_pgoff() and changing all callers to
directly call do_mmap(), which now no longer takes a vm_flags argument.Signed-off-by: Peter Collingbourne
Signed-off-by: Andrew Morton
Reviewed-by: Andrew Morton
Reviewed-by: David Hildenbrand
Link: http://lkml.kernel.org/r/20200727194109.1371462-1-pcc@google.com
Signed-off-by: Linus Torvalds -
When checking a performance change for will-it-scale scalability mmap test
[1], we found very high lock contention for spinlock of percpu counter
'vm_committed_as':94.14% 0.35% [kernel.kallsyms] [k] _raw_spin_lock_irqsave
48.21% _raw_spin_lock_irqsave;percpu_counter_add_batch;__vm_enough_memory;mmap_region;do_mmap;
45.91% _raw_spin_lock_irqsave;percpu_counter_add_batch;__do_munmap;Actually this heavy lock contention is not always necessary. The
'vm_committed_as' needs to be very precise when the strict
OVERCOMMIT_NEVER policy is set, which requires a rather small batch number
for the percpu counter.So keep 'batch' number unchanged for strict OVERCOMMIT_NEVER policy, and
lift it to 64X for OVERCOMMIT_ALWAYS and OVERCOMMIT_GUESS policies. Also
add a sysctl handler to adjust it when the policy is reconfigured.Benchmark with the same testcase in [1] shows 53% improvement on a 8C/16T
desktop, and 2097%(20X) on a 4S/72C/144T server. We tested with test
platforms in 0day (server, desktop and laptop), and 80%+ platforms shows
improvements with that test. And whether it shows improvements depends on
if the test mmap size is bigger than the batch number computed.And if the lift is 16X, 1/3 of the platforms will show improvements,
though it should help the mmap/unmap usage generally, as Michal Hocko
mentioned:: I believe that there are non-synthetic worklaods which would benefit from
: a larger batch. E.g. large in memory databases which do large mmaps
: during startups from multiple threads.[1] https://lore.kernel.org/lkml/20200305062138.GI5972@shao2-debian/
Signed-off-by: Feng Tang
Signed-off-by: Andrew Morton
Acked-by: Michal Hocko
Cc: Matthew Wilcox (Oracle)
Cc: Johannes Weiner
Cc: Mel Gorman
Cc: Qian Cai
Cc: Kees Cook
Cc: Andi Kleen
Cc: Tim Chen
Cc: Dave Hansen
Cc: Huang Ying
Cc: Christoph Lameter
Cc: Dennis Zhou
Cc: Haiyang Zhang
Cc: kernel test robot
Cc: "K. Y. Srinivasan"
Cc: Tejun Heo
Link: http://lkml.kernel.org/r/1589611660-89854-4-git-send-email-feng.tang@intel.com
Link: http://lkml.kernel.org/r/1592725000-73486-4-git-send-email-feng.tang@intel.com
Link: http://lkml.kernel.org/r/1594389708-60781-5-git-send-email-feng.tang@intel.com
Signed-off-by: Linus Torvalds -
percpu_counter_sum_positive() will provide more accurate info.
As with percpu_counter_read_positive(), in worst case the deviation could
be 'batch * nr_cpus', which is totalram_pages/256 for now, and will be
more when the batch gets enlarged.Its time cost is about 800 nanoseconds on a 2C/4T platform and 2~3
microseconds on a 2S/36C/72T Skylake server in normal case, and in worst
case where vm_committed_as's spinlock is under severe contention, it costs
30~40 microseconds for the 2S/36C/72T Skylake sever, which should be fine
for its only two users: /proc/meminfo and HyperV balloon driver's status
trace per second.Signed-off-by: Feng Tang
Signed-off-by: Andrew Morton
Acked-by: Michal Hocko # for /proc/meminfo
Cc: "K. Y. Srinivasan"
Cc: Haiyang Zhang
Cc: Matthew Wilcox (Oracle)
Cc: Johannes Weiner
Cc: Mel Gorman
Cc: Qian Cai
Cc: Andi Kleen
Cc: Tim Chen
Cc: Dave Hansen
Cc: Huang Ying
Cc: Christoph Lameter
Cc: Dennis Zhou
Cc: Kees Cook
Cc: kernel test robot
Cc: Tejun Heo
Link: http://lkml.kernel.org/r/1592725000-73486-3-git-send-email-feng.tang@intel.com
Link: http://lkml.kernel.org/r/1594389708-60781-3-git-send-email-feng.tang@intel.com
Signed-off-by: Linus Torvalds
10 Jun, 2020
3 commits
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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 -
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 -
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
05 Jun, 2020
2 commits
-
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 -
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
04 Jun, 2020
1 commit
-
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
...
03 Jun, 2020
1 commit
-
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
27 Apr, 2020
1 commit
-
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
01 Dec, 2019
2 commits
-
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 -
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
25 Sep, 2019
5 commits
-
This commits selects ARCH_HAS_ELF_RANDOMIZE when an arch uses the generic
topdown mmap layout functions so that this security feature is on by
default.Note that this commit also removes the possibility for arm64 to have elf
randomization and no MMU: without MMU, the security added by randomization
is worth nothing.Link: http://lkml.kernel.org/r/20190730055113.23635-6-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti
Acked-by: Catalin Marinas
Acked-by: Kees Cook
Reviewed-by: Christoph Hellwig
Reviewed-by: Luis Chamberlain
Cc: Albert Ou
Cc: Alexander Viro
Cc: Christoph Hellwig
Cc: James Hogan
Cc: Palmer Dabbelt
Cc: Paul Burton
Cc: Ralf Baechle
Cc: Russell King
Cc: Will Deacon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
arm64 handles top-down mmap layout in a way that can be easily reused by
other architectures, so make it available in mm. It then introduces a new
config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other
architectures to benefit from those functions. Note that this new config
depends on MMU being enabled, if selected without MMU support, a warning
will be thrown.Link: http://lkml.kernel.org/r/20190730055113.23635-5-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti
Suggested-by: Christoph Hellwig
Acked-by: Catalin Marinas
Acked-by: Kees Cook
Reviewed-by: Christoph Hellwig
Reviewed-by: Luis Chamberlain
Cc: Albert Ou
Cc: Alexander Viro
Cc: James Hogan
Cc: Palmer Dabbelt
Cc: Paul Burton
Cc: Ralf Baechle
Cc: Russell King
Cc: Will Deacon
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch series "Provide generic top-down mmap layout functions", v6.
This series introduces generic functions to make top-down mmap layout
easily accessible to architectures, in particular riscv which was the
initial goal of this series. The generic implementation was taken from
arm64 and used successively by arm, mips and finally riscv.Note that in addition the series fixes 2 issues:
- stack randomization was taken into account even if not necessary.
- [1] fixed an issue with mmap base which did not take into account
randomization but did not report it to arm and mips, so by moving arm64
into a generic library, this problem is now fixed for both
architectures.This work is an effort to factorize architecture functions to avoid code
duplication and oversights as in [1].[1]: https://www.mail-archive.com/linux-kernel@vger.kernel.org/msg1429066.html
This patch (of 14):
This preparatory commit moves this function so that further introduction
of generic topdown mmap layout is contained only in mm/util.c.Link: http://lkml.kernel.org/r/20190730055113.23635-2-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti
Acked-by: Kees Cook
Reviewed-by: Christoph Hellwig
Reviewed-by: Luis Chamberlain
Cc: Russell King
Cc: Catalin Marinas
Cc: Will Deacon
Cc: Ralf Baechle
Cc: Paul Burton
Cc: James Hogan
Cc: Palmer Dabbelt
Cc: Albert Ou
Cc: Alexander Viro
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch series "THP aware uprobe", v13.
This patchset makes uprobe aware of THPs.
Currently, when uprobe is attached to text on THP, the page is split by
FOLL_SPLIT. As a result, uprobe eliminates the performance benefit of
THP.This set makes uprobe THP-aware. Instead of FOLL_SPLIT, we introduces
FOLL_SPLIT_PMD, which only split PMD for uprobe.After all uprobes within the THP are removed, the PTE-mapped pages are
regrouped as huge PMD.This set (plus a few THP patches) is also available at
https://github.com/liu-song-6/linux/tree/uprobe-thp
This patch (of 6):
Move memcmp_pages() to mm/util.c and pages_identical() to mm.h, so that we
can use them in other files.Link: http://lkml.kernel.org/r/20190815164525.1848545-2-songliubraving@fb.com
Signed-off-by: Song Liu
Acked-by: Kirill A. Shutemov
Reviewed-by: Oleg Nesterov
Cc: Johannes Weiner
Cc: Matthew Wilcox
Cc: William Kucharski
Cc: Srikar Dronamraju
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Replace 1 << compound_order(page) with compound_nr(page). Minor
improvements in readability.Link: http://lkml.kernel.org/r/20190721104612.19120-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle)
Reviewed-by: Andrew Morton
Reviewed-by: Ira Weiny
Acked-by: Kirill A. Shutemov
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Jul, 2019
1 commit
-
locked_vm accounting is done roughly the same way in five places, so
unify them in a helper.Include the helper's caller in the debug print to distinguish between
callsites.Error codes stay the same, so user-visible behavior does too. The one
exception is that the -EPERM case in tce_account_locked_vm is removed
because Alexey has never seen it triggered.[daniel.m.jordan@oracle.com: v3]
Link: http://lkml.kernel.org/r/20190529205019.20927-1-daniel.m.jordan@oracle.com
[sfr@canb.auug.org.au: fix mm/util.c]
Link: http://lkml.kernel.org/r/20190524175045.26897-1-daniel.m.jordan@oracle.com
Signed-off-by: Daniel Jordan
Signed-off-by: Stephen Rothwell
Tested-by: Alexey Kardashevskiy
Acked-by: Alex Williamson
Cc: Alan Tull
Cc: Alex Williamson
Cc: Benjamin Herrenschmidt
Cc: Christoph Lameter
Cc: Christophe Leroy
Cc: Davidlohr Bueso
Cc: Jason Gunthorpe
Cc: Mark Rutland
Cc: Michael Ellerman
Cc: Moritz Fischer
Cc: Paul Mackerras
Cc: Steve Sistare
Cc: Wu Hao
Cc: Ira Weiny
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
13 Jul, 2019
1 commit
-
Always build mm/gup.c so that we don't have to provide separate nommu
stubs. Also merge the get_user_pages_fast and __get_user_pages_fast stubs
when HAVE_FAST_GUP into the main implementations, which will never call
the fast path if HAVE_FAST_GUP is not set.This also ensures the new put_user_pages* helpers are available for nommu,
as those are currently missing, which would create a problem as soon as we
actually grew users for it.Link: http://lkml.kernel.org/r/20190625143715.1689-13-hch@lst.de
Signed-off-by: Christoph Hellwig
Cc: Andrey Konovalov
Cc: Benjamin Herrenschmidt
Cc: David Miller
Cc: James Hogan
Cc: Jason Gunthorpe
Cc: Khalid Aziz
Cc: Michael Ellerman
Cc: Nicholas Piggin
Cc: Paul Burton
Cc: Paul Mackerras
Cc: Ralf Baechle
Cc: Rich Felker
Cc: Yoshinori Sato
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
02 Jun, 2019
1 commit
-
The commit a3b609ef9f8b ("proc read mm's {arg,env}_{start,end} with mmap
semaphore taken.") added synchronization of reading argument/environment
boundaries under mmap_sem. Later commit 88aa7cc688d4 ("mm: introduce
arg_lock to protect arg_start|end and env_start|end in mm_struct") avoided
the coarse use of mmap_sem in similar situations. But there still
remained two places that (mis)use mmap_sem.get_cmdline should also use arg_lock instead of mmap_sem when it reads the
boundaries.The second place that should use arg_lock is in prctl_set_mm. By
protecting the boundaries fields with the arg_lock, we can downgrade
mmap_sem to reader lock (analogous to what we already do in
prctl_set_mm_map).[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/20190502125203.24014-3-mkoutny@suse.com
Fixes: 88aa7cc688d4 ("mm: introduce arg_lock to protect arg_start|end and env_start|end in mm_struct")
Signed-off-by: Michal Koutný
Signed-off-by: Laurent Dufour
Co-developed-by: Laurent Dufour
Reviewed-by: Cyrill Gorcunov
Acked-by: Michal Hocko
Cc: Yang Shi
Cc: Mateusz Guzik
Cc: Kirill Tkhai
Cc: Konstantin Khlebnikov
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
21 May, 2019
1 commit
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Add SPDX license identifiers to all files which:
- Have no license information of any form
- Have EXPORT_.*_SYMBOL_GPL inside which was used in the
initial scan/conversion to ignore the fileThese files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:GPL-2.0-only
Signed-off-by: Thomas Gleixner
Signed-off-by: Greg Kroah-Hartman
15 May, 2019
2 commits
-
With the default overcommit==guess we occasionally run into mmap
rejections despite plenty of memory that would get dropped under
pressure but just isn't accounted reclaimable. One example of this is
dying cgroups pinned by some page cache. A previous case was auxiliary
path name memory associated with dentries; we have since annotated
those allocations to avoid overcommit failures (see d79f7aa496fc ("mm:
treat indirectly reclaimable memory as free in overcommit logic")).But trying to classify all allocated memory reliably as reclaimable
and unreclaimable is a bit of a fool's errand. There could be a myriad
of dependencies that constantly change with kernel versions.It becomes even more questionable of an effort when considering how
this estimate of available memory is used: it's not compared to the
system-wide allocated virtual memory in any way. It's not even
compared to the allocating process's address space. It's compared to
the single allocation request at hand!So we have an elaborate left-hand side of the equation that tries to
assess the exact breathing room the system has available down to a
page - and then compare it to an isolated allocation request with no
additional context. We could fail an allocation of N bytes, but for
two allocations of N/2 bytes we'd do this elaborate dance twice in a
row and then still let N bytes of virtual memory through. This doesn't
make a whole lot of sense.Let's take a step back and look at the actual goal of the
heuristic. From the documentation:Heuristic overcommit handling. Obvious overcommits of address
space are refused. Used for a typical system. It ensures a
seriously wild allocation fails while allowing overcommit to
reduce swap usage. root is allowed to allocate slightly more
memory in this mode. This is the default.If all we want to do is catch clearly bogus allocation requests
irrespective of the general virtual memory situation, the physical
memory counter-part doesn't need to be that complicated, either.When in GUESS mode, catch wild allocations by comparing their request
size to total amount of ram and swap in the system.Link: http://lkml.kernel.org/r/20190412191418.26333-1-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner
Acked-by: Roman Gushchin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
To facilitate additional options to get_user_pages_fast() change the
singular write parameter to be gup_flags.This patch does not change any functionality. New functionality will
follow in subsequent patches.Some of the get_user_pages_fast() call sites were unchanged because they
already passed FOLL_WRITE or 0 for the write parameter.NOTE: It was suggested to change the ordering of the get_user_pages_fast()
arguments to ensure that callers were converted. This breaks the current
GUP call site convention of having the returned pages be the final
parameter. So the suggestion was rejected.Link: http://lkml.kernel.org/r/20190328084422.29911-4-ira.weiny@intel.com
Link: http://lkml.kernel.org/r/20190317183438.2057-4-ira.weiny@intel.com
Signed-off-by: Ira Weiny
Reviewed-by: Mike Marshall
Cc: Aneesh Kumar K.V
Cc: Benjamin Herrenschmidt
Cc: Borislav Petkov
Cc: Dan Williams
Cc: "David S. Miller"
Cc: Heiko Carstens
Cc: Ingo Molnar
Cc: James Hogan
Cc: Jason Gunthorpe
Cc: John Hubbard
Cc: "Kirill A. Shutemov"
Cc: Martin Schwidefsky
Cc: Michal Hocko
Cc: Paul Mackerras
Cc: Peter Zijlstra
Cc: Ralf Baechle
Cc: Rich Felker
Cc: Thomas Gleixner
Cc: Yoshinori Sato
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Apr, 2019
1 commit
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The kerneldoc misdescribes strndup_user()'s return value.
Cc: Dan Carpenter
Cc: Timur Tabi
Cc: Mihai Caraman
Cc: Kumar Gala
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
06 Mar, 2019
1 commit
-
Many kernel-doc comments in mm/ have the return value descriptions
either misformatted or omitted at all which makes kernel-doc script
unhappy:$ make V=1 htmldocs
...
./mm/util.c:36: info: Scanning doc for kstrdup
./mm/util.c:41: warning: No description found for return value of 'kstrdup'
./mm/util.c:57: info: Scanning doc for kstrdup_const
./mm/util.c:66: warning: No description found for return value of 'kstrdup_const'
./mm/util.c:75: info: Scanning doc for kstrndup
./mm/util.c:83: warning: No description found for return value of 'kstrndup'
...Fixing the formatting and adding the missing return value descriptions
eliminates ~100 such warnings.Link: http://lkml.kernel.org/r/1549549644-4903-4-git-send-email-rppt@linux.ibm.com
Signed-off-by: Mike Rapoport
Reviewed-by: Andrew Morton
Cc: Jonathan Corbet
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
22 Feb, 2019
1 commit
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memdump_user usually gets fed unchecked userspace input. Blasting a
full backtrace into dmesg every time is a bit excessive - I'm not sure
on the kernel rule in general, but at least in drm we're trying not to
let unpriviledge userspace spam the logs freely. Definitely not entire
warning backtraces.It also means more filtering for our CI, because our testsuite exercises
these corner cases and so hits these a lot.Link: http://lkml.kernel.org/r/20190220204058.11676-1-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter
Reviewed-by: Andrew Morton
Acked-by: Michal Hocko
Reviewed-by: Kees Cook
Cc: Mike Rapoport
Cc: Roman Gushchin
Cc: Vlastimil Babka
Cc: Jan Stancek
Cc: Andrey Ryabinin
Cc: "Michael S. Tsirkin"
Cc: Huang Ying
Cc: Bartosz Golaszewski
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
09 Jan, 2019
1 commit
-
LTP proc01 testcase has been observed to rarely trigger crashes
on arm64:
page_mapped+0x78/0xb4
stable_page_flags+0x27c/0x338
kpageflags_read+0xfc/0x164
proc_reg_read+0x7c/0xb8
__vfs_read+0x58/0x178
vfs_read+0x90/0x14c
SyS_read+0x60/0xc0The issue is that page_mapped() assumes that if compound page is not
huge, then it must be THP. But if this is 'normal' compound page
(COMPOUND_PAGE_DTOR), then following loop can keep running (for
HPAGE_PMD_NR iterations) until it tries to read from memory that isn't
mapped and triggers a panic:for (i = 0; i < hpage_nr_pages(page); i++) {
if (atomic_read(&page[i]._mapcount) >= 0)
return true;
}I could replicate this on x86 (v4.20-rc4-98-g60b548237fed) only
with a custom kernel module [1] which:
- allocates compound page (PAGEC) of order 1
- allocates 2 normal pages (COPY), which are initialized to 0xff (to
satisfy _mapcount >= 0)
- 2 PAGEC page structs are copied to address of first COPY page
- second page of COPY is marked as not present
- call to page_mapped(COPY) now triggers fault on access to 2nd COPY
page at offset 0x30 (_mapcount)[1] https://github.com/jstancek/reproducers/blob/master/kernel/page_mapped_crash/repro.c
Fix the loop to iterate for "1 << compound_order" pages.
Kirrill said "IIRC, sound subsystem can producuce custom mapped compound
pages".Link: http://lkml.kernel.org/r/c440d69879e34209feba21e12d236d06bc0a25db.1543577156.git.jstancek@redhat.com
Fixes: e1534ae95004 ("mm: differentiate page_mapped() from page_mapcount() for compound pages")
Signed-off-by: Jan Stancek
Debugged-by: Laszlo Ersek
Suggested-by: "Kirill A. Shutemov"
Acked-by: Michal Hocko
Acked-by: Kirill A. Shutemov
Reviewed-by: David Hildenbrand
Reviewed-by: Andrea Arcangeli
Cc:
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
29 Dec, 2018
1 commit
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totalram_pages and totalhigh_pages are made static inline function.
Main motivation was that managed_page_count_lock handling was complicating
things. It was discussed in length here,
https://lore.kernel.org/patchwork/patch/995739/#1181785 So it seemes
better to remove the lock and convert variables to atomic, with preventing
poteintial store-to-read tearing as a bonus.[akpm@linux-foundation.org: coding style fixes]
Link: http://lkml.kernel.org/r/1542090790-21750-4-git-send-email-arunks@codeaurora.org
Signed-off-by: Arun KS
Suggested-by: Michal Hocko
Suggested-by: Vlastimil Babka
Reviewed-by: Konstantin Khlebnikov
Reviewed-by: Pavel Tatashin
Acked-by: Michal Hocko
Acked-by: Vlastimil Babka
Cc: David Hildenbrand
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Oct, 2018
2 commits
-
vfree() might sleep if called not in interrupt context. So does kvfree()
too. Fix misleading kvfree()'s comment about allowed context.Link: http://lkml.kernel.org/r/20180914130512.10394-1-aryabinin@virtuozzo.com
Fixes: 04b8e946075d ("mm/util.c: improve kvfree() kerneldoc")
Signed-off-by: Andrey Ryabinin
Reviewed-by: Andrew Morton
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
The vmstat counter NR_INDIRECTLY_RECLAIMABLE_BYTES was introduced by
commit eb59254608bc ("mm: introduce NR_INDIRECTLY_RECLAIMABLE_BYTES") with
the goal of accounting objects that can be reclaimed, but cannot be
allocated via a SLAB_RECLAIM_ACCOUNT cache. This is now possible via
kmalloc() with __GFP_RECLAIMABLE flag, and the dcache external names user
is converted.The counter is however still useful for accounting direct page allocations
(i.e. not slab) with a shrinker, such as the ION page pool. So keep it,
and:- change granularity to pages to be more like other counters; sub-page
allocations should be able to use kmalloc
- rename the counter to NR_KERNEL_MISC_RECLAIMABLE
- expose the counter again in vmstat as "nr_kernel_misc_reclaimable"; we can
again remove the check for not printing "hidden" countersLink: http://lkml.kernel.org/r/20180731090649.16028-5-vbabka@suse.cz
Signed-off-by: Vlastimil Babka
Acked-by: Christoph Lameter
Acked-by: Roman Gushchin
Cc: Vijayanand Jitta
Cc: Laura Abbott
Cc: Sumit Semwal
Cc: David Rientjes
Cc: Johannes Weiner
Cc: Joonsoo Kim
Cc: Matthew Wilcox
Cc: Mel Gorman
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
16 Oct, 2018
1 commit
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Export this routine so that we can use it later in devm_kstrdup_const()
and devm_kfree().Signed-off-by: Bartosz Golaszewski
Reviewed-by: Bjorn Andersson
Acked-by: Mike Rapoport
Acked-by: Rasmus Villemoes
Reviewed-by: Geert Uytterhoeven
Reviewed-by: Andy Shevchenko
Signed-off-by: Greg Kroah-Hartman
05 Sep, 2018
1 commit
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Scooped from an email from Matthew.
Cc: Mike Rapoport
Cc: Jonathan Corbet
Cc: Matthew Wilcox
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
24 Aug, 2018
2 commits
-
Link: http://lkml.kernel.org/r/1532626360-16650-3-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport
Reviewed-by: Andrew Morton
Cc: Jonathan Corbet
Cc: Matthew Wilcox
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Patch series "memory management documentation updates", v3.
Here are several updates to the mm documentation.
Aside from really minor changes in the first three patches, the updates
are:* move the documentation of kstrdup and friends to "String Manipulation"
section
* split memory management API into a separate .rst file
* adjust formating of the GFP flags description and include it in the
reference documentation.This patch (of 7):
The description of the strndup_user function misses '*' character at the
beginning of the comment to be proper kernel-doc. Add the missing
character.Link: http://lkml.kernel.org/r/1532626360-16650-2-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport
Reviewed-by: Andrew Morton
Cc: Jonathan Corbet
Cc: Matthew Wilcox
Cc: Michal Hocko
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
08 Jun, 2018
1 commit
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kvmalloc warned about incompatible gfp_mask to catch abusers (mostly
GFP_NOFS) with an intention that this will motivate authors of the code
to fix those. Linus argues that this just motivates people to do even
more hacks likeif (gfp == GFP_KERNEL)
kvmalloc
else
kmallocI haven't seen this happening much (Linus pointed to bucket_lock special
cases an atomic allocation but my git foo hasn't found much more) but it
is true that we can grow those in future. Therefore Linus suggested to
simply not fallback to vmalloc for incompatible gfp flags and rather
stick with the kmalloc path.Link: http://lkml.kernel.org/r/20180601115329.27807-1-mhocko@kernel.org
Signed-off-by: Michal Hocko
Suggested-by: Linus Torvalds
Cc: Tom Herbert
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Apr, 2018
2 commits
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Mike Rapoport says:
These patches convert files in Documentation/vm to ReST format, add an
initial index and link it to the top level documentation.There are no contents changes in the documentation, except few spelling
fixes. The relatively large diffstat stems from the indentation and
paragraph wrapping changes.I've tried to keep the formatting as consistent as possible, but I could
miss some places that needed markup and add some markup where it was not
necessary.[jc: significant conflicts in vm/hmm.rst]
-
Signed-off-by: Mike Rapoport
Signed-off-by: Jonathan Corbet
