<feed xmlns='http://www.w3.org/2005/Atom'>
<title>user/sven/linux.git/include, branch v5.13.1</title>
<subtitle>Linux Kernel
</subtitle>
<id>https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.13.1</id>
<link rel='self' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/atom?h=v5.13.1'/>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/'/>
<updated>2021-06-27T20:32:54Z</updated>
<entry>
<title>Revert "signal: Allow tasks to cache one sigqueue struct"</title>
<updated>2021-06-27T20:32:54Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-06-27T20:32:54Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=b4b27b9eed8ebdbf9f3046197d29d733c8c944f3'/>
<id>urn:sha1:b4b27b9eed8ebdbf9f3046197d29d733c8c944f3</id>
<content type='text'>
This reverts commits 4bad58ebc8bc4f20d89cff95417c9b4674769709 (and
399f8dd9a866e107639eabd3c1979cd526ca3a98, which tried to fix it).

I do not believe these are correct, and I'm about to release 5.13, so am
reverting them out of an abundance of caution.

The locking is odd, and appears broken.

On the allocation side (in __sigqueue_alloc()), the locking is somewhat
straightforward: it depends on sighand-&gt;siglock.  Since one caller
doesn't hold that lock, it further then tests 'sigqueue_flags' to avoid
the case with no locks held.

On the freeing side (in sigqueue_cache_or_free()), there is no locking
at all, and the logic instead depends on 'current' being a single
thread, and not able to race with itself.

To make things more exciting, there's also the data race between freeing
a signal and allocating one, which is handled by using WRITE_ONCE() and
READ_ONCE(), and being mutually exclusive wrt the initial state (ie
freeing will only free if the old state was NULL, while allocating will
obviously only use the value if it was non-NULL, so only one or the
other will actually act on the value).

However, while the free-&gt;alloc paths do seem mutually exclusive thanks
to just the data value dependency, it's not clear what the memory
ordering constraints are on it.  Could writes from the previous
allocation possibly be delayed and seen by the new allocation later,
causing logical inconsistencies?

So it's all very exciting and unusual.

And in particular, it seems that the freeing side is incorrect in
depending on "current" being single-threaded.  Yes, 'current' is a
single thread, but in the presense of asynchronous events even a single
thread can have data races.

And such asynchronous events can and do happen, with interrupts causing
signals to be flushed and thus free'd (for example - sending a
SIGCONT/SIGSTOP can happen from interrupt context, and can flush
previously queued process control signals).

So regardless of all the other questions about the memory ordering and
locking for this new cached allocation, the sigqueue_cache_or_free()
assumptions seem to be fundamentally incorrect.

It may be that people will show me the errors of my ways, and tell me
why this is all safe after all.  We can reinstate it if so.  But my
current belief is that the WRITE_ONCE() that sets the cached entry needs
to be a smp_store_release(), and the READ_ONCE() that finds a cached
entry needs to be a smp_load_acquire() to handle memory ordering
correctly.

And the sequence in sigqueue_cache_or_free() would need to either use a
lock or at least be interrupt-safe some way (perhaps by using something
like the percpu 'cmpxchg': it doesn't need to be SMP-safe, but like the
percpu operations it needs to be interrupt-safe).

Fixes: 399f8dd9a866 ("signal: Prevent sigqueue caching after task got released")
Fixes: 4bad58ebc8bc ("signal: Allow tasks to cache one sigqueue struct")
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Oleg Nesterov &lt;oleg@redhat.com&gt;
Cc: Christian Brauner &lt;christian.brauner@ubuntu.com&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>Merge branch 'akpm' (patches from Andrew)</title>
<updated>2021-06-25T18:05:03Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-06-25T18:05:03Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=7ce32ac6fb2fc73584b567c73ae0c47528954ec6'/>
<id>urn:sha1:7ce32ac6fb2fc73584b567c73ae0c47528954ec6</id>
<content type='text'>
Merge misc fixes from Andrew Morton:
 "24 patches, based on 4a09d388f2ab382f217a764e6a152b3f614246f6.

  Subsystems affected by this patch series: mm (thp, vmalloc, hugetlb,
  memory-failure, and pagealloc), nilfs2, kthread, MAINTAINERS, and
  mailmap"

* emailed patches from Andrew Morton &lt;akpm@linux-foundation.org&gt;: (24 commits)
  mailmap: add Marek's other e-mail address and identity without diacritics
  MAINTAINERS: fix Marek's identity again
  mm/page_alloc: do bulk array bounds check after checking populated elements
  mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array
  mm/hwpoison: do not lock page again when me_huge_page() successfully recovers
  mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned
  mm/memory-failure: use a mutex to avoid memory_failure() races
  mm, futex: fix shared futex pgoff on shmem huge page
  kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync()
  kthread_worker: split code for canceling the delayed work timer
  mm/vmalloc: unbreak kasan vmalloc support
  KVM: s390: prepare for hugepage vmalloc
  mm/vmalloc: add vmalloc_no_huge
  nilfs2: fix memory leak in nilfs_sysfs_delete_device_group
  mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk()
  mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes
  mm: page_vma_mapped_walk(): get vma_address_end() earlier
  mm: page_vma_mapped_walk(): use goto instead of while (1)
  mm: page_vma_mapped_walk(): add a level of indentation
  mm: page_vma_mapped_walk(): crossing page table boundary
  ...
</content>
</entry>
<entry>
<title>userfaultfd: uapi: fix UFFDIO_CONTINUE ioctl request definition</title>
<updated>2021-06-25T17:53:26Z</updated>
<author>
<name>Gleb Fotengauer-Malinovskiy</name>
<email>glebfm@altlinux.org</email>
</author>
<published>2021-06-25T17:36:55Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=808e9df477757955a9644ca323010339be0c40ee'/>
<id>urn:sha1:808e9df477757955a9644ca323010339be0c40ee</id>
<content type='text'>
This ioctl request reads from uffdio_continue structure written by
userspace which justifies _IOC_WRITE flag.  It also writes back to that
structure which justifies _IOC_READ flag.

See NOTEs in include/uapi/asm-generic/ioctl.h for more information.

Fixes: f619147104c8 ("userfaultfd: add UFFDIO_CONTINUE ioctl")
Signed-off-by: Gleb Fotengauer-Malinovskiy &lt;glebfm@altlinux.org&gt;
Acked-by: Peter Xu &lt;peterx@redhat.com&gt;
Reviewed-by: Axel Rasmussen &lt;axelrasmussen@google.com&gt;
Reviewed-by: Dmitry V. Levin &lt;ldv@altlinux.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>Merge tag 'ceph-for-5.13-rc8' of https://github.com/ceph/ceph-client</title>
<updated>2021-06-25T16:50:30Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-06-25T16:50:30Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=edf54d9d0ae0a230199a58e57b46c2d4b37a1462'/>
<id>urn:sha1:edf54d9d0ae0a230199a58e57b46c2d4b37a1462</id>
<content type='text'>
Pull ceph fixes from Ilya Dryomov:
 "Two regression fixes from the merge window: one in the auth code
  affecting old clusters and one in the filesystem for proper
  propagation of MDS request errors.

  Also included a locking fix for async creates, marked for stable"

* tag 'ceph-for-5.13-rc8' of https://github.com/ceph/ceph-client:
  libceph: set global_id as soon as we get an auth ticket
  libceph: don't pass result into ac-&gt;ops-&gt;handle_reply()
  ceph: fix error handling in ceph_atomic_open and ceph_lookup
  ceph: must hold snap_rwsem when filling inode for async create
</content>
</entry>
<entry>
<title>mm, futex: fix shared futex pgoff on shmem huge page</title>
<updated>2021-06-25T02:40:54Z</updated>
<author>
<name>Hugh Dickins</name>
<email>hughd@google.com</email>
</author>
<published>2021-06-25T01:39:52Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=fe19bd3dae3d15d2fbfdb3de8839a6ea0fe94264'/>
<id>urn:sha1:fe19bd3dae3d15d2fbfdb3de8839a6ea0fe94264</id>
<content type='text'>
If more than one futex is placed on a shmem huge page, it can happen
that waking the second wakes the first instead, and leaves the second
waiting: the key's shared.pgoff is wrong.

When 3.11 commit 13d60f4b6ab5 ("futex: Take hugepages into account when
generating futex_key"), the only shared huge pages came from hugetlbfs,
and the code added to deal with its exceptional page-&gt;index was put into
hugetlb source.  Then that was missed when 4.8 added shmem huge pages.

page_to_pgoff() is what others use for this nowadays: except that, as
currently written, it gives the right answer on hugetlbfs head, but
nonsense on hugetlbfs tails.  Fix that by calling hugetlbfs-specific
hugetlb_basepage_index() on PageHuge tails as well as on head.

Yes, it's unconventional to declare hugetlb_basepage_index() there in
pagemap.h, rather than in hugetlb.h; but I do not expect anything but
page_to_pgoff() ever to need it.

[akpm@linux-foundation.org: give hugetlb_basepage_index() prototype the correct scope]

Link: https://lkml.kernel.org/r/b17d946b-d09-326e-b42a-52884c36df32@google.com
Fixes: 800d8c63b2e9 ("shmem: add huge pages support")
Reported-by: Neel Natu &lt;neelnatu@google.com&gt;
Signed-off-by: Hugh Dickins &lt;hughd@google.com&gt;
Reviewed-by: Matthew Wilcox (Oracle) &lt;willy@infradead.org&gt;
Acked-by: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: "Kirill A. Shutemov" &lt;kirill.shutemov@linux.intel.com&gt;
Cc: Zhang Yi &lt;wetpzy@gmail.com&gt;
Cc: Mel Gorman &lt;mgorman@techsingularity.net&gt;
Cc: Mike Kravetz &lt;mike.kravetz@oracle.com&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Darren Hart &lt;dvhart@infradead.org&gt;
Cc: Davidlohr Bueso &lt;dave@stgolabs.net&gt;
Cc: &lt;stable@vger.kernel.org&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>mm/vmalloc: add vmalloc_no_huge</title>
<updated>2021-06-25T02:40:53Z</updated>
<author>
<name>Claudio Imbrenda</name>
<email>imbrenda@linux.ibm.com</email>
</author>
<published>2021-06-25T01:39:36Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=15a64f5a8870b5610b616a4aa753262dfaa5d76e'/>
<id>urn:sha1:15a64f5a8870b5610b616a4aa753262dfaa5d76e</id>
<content type='text'>
Patch series "mm: add vmalloc_no_huge and use it", v4.

Add vmalloc_no_huge() and export it, so modules can allocate memory with
small pages.

Use the newly added vmalloc_no_huge() in KVM on s390 to get around a
hardware limitation.

This patch (of 2):

Commit 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings") added
support for hugepage vmalloc mappings, it also added the flag
VM_NO_HUGE_VMAP for __vmalloc_node_range to request the allocation to be
performed with 0-order non-huge pages.

This flag is not accessible when calling vmalloc, the only option is to
call directly __vmalloc_node_range, which is not exported.

This means that a module can't vmalloc memory with small pages.

Case in point: KVM on s390x needs to vmalloc a large area, and it needs
to be mapped with non-huge pages, because of a hardware limitation.

This patch adds the function vmalloc_no_huge, which works like vmalloc,
but it is guaranteed to always back the mapping using small pages.  This
new function is exported, therefore it is usable by modules.

[akpm@linux-foundation.org: whitespace fixes, per Christoph]

Link: https://lkml.kernel.org/r/20210614132357.10202-1-imbrenda@linux.ibm.com
Link: https://lkml.kernel.org/r/20210614132357.10202-2-imbrenda@linux.ibm.com
Fixes: 121e6f3258fe3 ("mm/vmalloc: hugepage vmalloc mappings")
Signed-off-by: Claudio Imbrenda &lt;imbrenda@linux.ibm.com&gt;
Reviewed-by: Uladzislau Rezki (Sony) &lt;urezki@gmail.com&gt;
Acked-by: Nicholas Piggin &lt;npiggin@gmail.com&gt;
Reviewed-by: David Hildenbrand &lt;david@redhat.com&gt;
Acked-by: David Rientjes &lt;rientjes@google.com&gt;
Cc: Uladzislau Rezki (Sony) &lt;urezki@gmail.com&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Ingo Molnar &lt;mingo@redhat.com&gt;
Cc: Christoph Hellwig &lt;hch@infradead.org&gt;
Cc: Cornelia Huck &lt;cohuck@redhat.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
</entry>
<entry>
<title>libceph: set global_id as soon as we get an auth ticket</title>
<updated>2021-06-24T19:03:17Z</updated>
<author>
<name>Ilya Dryomov</name>
<email>idryomov@gmail.com</email>
</author>
<published>2021-06-21T10:17:40Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=03af4c7bad8ca59143bca488b90b3775d10d7f94'/>
<id>urn:sha1:03af4c7bad8ca59143bca488b90b3775d10d7f94</id>
<content type='text'>
Commit 61ca49a9105f ("libceph: don't set global_id until we get an
auth ticket") delayed the setting of global_id too much.  It is set
only after all tickets are received, but in pre-nautilus clusters an
auth ticket and the service tickets are obtained in separate steps
(for a total of three MAuth replies).  When the service tickets are
requested, global_id is used to build an authorizer; if global_id is
still 0 we never get them and fail to establish the session.

Moving the setting of global_id into protocol implementations.  This
way global_id can be set exactly when an auth ticket is received, not
sooner nor later.

Fixes: 61ca49a9105f ("libceph: don't set global_id until we get an auth ticket")
Signed-off-by: Ilya Dryomov &lt;idryomov@gmail.com&gt;
Reviewed-by: Jeff Layton &lt;jlayton@kernel.org&gt;
</content>
</entry>
<entry>
<title>libceph: don't pass result into ac-&gt;ops-&gt;handle_reply()</title>
<updated>2021-06-24T19:03:16Z</updated>
<author>
<name>Ilya Dryomov</name>
<email>idryomov@gmail.com</email>
</author>
<published>2021-06-21T09:53:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=3c0d0894320cc517fda657c69939cd0313d0b4e2'/>
<id>urn:sha1:3c0d0894320cc517fda657c69939cd0313d0b4e2</id>
<content type='text'>
There is no result to pass in msgr2 case because authentication
failures are reported through auth_bad_method frame and in MAuth
case an error is returned immediately.

Signed-off-by: Ilya Dryomov &lt;idryomov@gmail.com&gt;
Reviewed-by: Jeff Layton &lt;jlayton@kernel.org&gt;
</content>
</entry>
<entry>
<title>locking/lockdep: Improve noinstr vs errors</title>
<updated>2021-06-22T11:56:43Z</updated>
<author>
<name>Peter Zijlstra</name>
<email>peterz@infradead.org</email>
</author>
<published>2021-06-21T11:12:38Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=49faa77759b211fff344898edc23bb780707fff5'/>
<id>urn:sha1:49faa77759b211fff344898edc23bb780707fff5</id>
<content type='text'>
Better handle the failure paths.

  vmlinux.o: warning: objtool: debug_locks_off()+0x23: call to console_verbose() leaves .noinstr.text section
  vmlinux.o: warning: objtool: debug_locks_off()+0x19: call to __kasan_check_write() leaves .noinstr.text section

  debug_locks_off+0x19/0x40:
  instrument_atomic_write at include/linux/instrumented.h:86
  (inlined by) __debug_locks_off at include/linux/debug_locks.h:17
  (inlined by) debug_locks_off at lib/debug_locks.c:41

Fixes: 6eebad1ad303 ("lockdep: __always_inline more for noinstr")
Signed-off-by: Peter Zijlstra (Intel) &lt;peterz@infradead.org&gt;
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
Link: https://lore.kernel.org/r/20210621120120.784404944@infradead.org
</content>
</entry>
<entry>
<title>Merge tag 'net-5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2021-06-19T01:55:29Z</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2021-06-19T01:55:29Z</published>
<link rel='alternate' type='text/html' href='https://git.stealer.net/cgit.cgi/user/sven/linux.git/commit/?id=9ed13a17e38e0537e24d9b507645002bf8d0201f'/>
<id>urn:sha1:9ed13a17e38e0537e24d9b507645002bf8d0201f</id>
<content type='text'>
Pull networking fixes from Jakub Kicinski:
 "Networking fixes for 5.13-rc7, including fixes from wireless, bpf,
  bluetooth, netfilter and can.

  Current release - regressions:

   - mlxsw: spectrum_qdisc: Pass handle, not band number to find_class()
     to fix modifying offloaded qdiscs

   - lantiq: net: fix duplicated skb in rx descriptor ring

   - rtnetlink: fix regression in bridge VLAN configuration, empty info
     is not an error, bot-generated "fix" was not needed

   - libbpf: s/rx/tx/ typo on umem-&gt;rx_ring_setup_done to fix umem
     creation

  Current release - new code bugs:

   - ethtool: fix NULL pointer dereference during module EEPROM dump via
     the new netlink API

   - mlx5e: don't update netdev RQs with PTP-RQ, the special purpose
     queue should not be visible to the stack

   - mlx5e: select special PTP queue only for SKBTX_HW_TSTAMP skbs

   - mlx5e: verify dev is present in get devlink port ndo, avoid a panic

  Previous releases - regressions:

   - neighbour: allow NUD_NOARP entries to be force GCed

   - further fixes for fallout from reorg of WiFi locking (staging:
     rtl8723bs, mac80211, cfg80211)

   - skbuff: fix incorrect msg_zerocopy copy notifications

   - mac80211: fix NULL ptr deref for injected rate info

   - Revert "net/mlx5: Arm only EQs with EQEs" it may cause missed IRQs

  Previous releases - always broken:

   - bpf: more speculative execution fixes

   - netfilter: nft_fib_ipv6: skip ipv6 packets from any to link-local

   - udp: fix race between close() and udp_abort() resulting in a panic

   - fix out of bounds when parsing TCP options before packets are
     validated (in netfilter: synproxy, tc: sch_cake and mptcp)

   - mptcp: improve operation under memory pressure, add missing
     wake-ups

   - mptcp: fix double-lock/soft lookup in subflow_error_report()

   - bridge: fix races (null pointer deref and UAF) in vlan tunnel
     egress

   - ena: fix DMA mapping function issues in XDP

   - rds: fix memory leak in rds_recvmsg

  Misc:

   - vrf: allow larger MTUs

   - icmp: don't send out ICMP messages with a source address of 0.0.0.0

   - cdc_ncm: switch to eth%d interface naming"

* tag 'net-5.13-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (139 commits)
  net: ethernet: fix potential use-after-free in ec_bhf_remove
  selftests/net: Add icmp.sh for testing ICMP dummy address responses
  icmp: don't send out ICMP messages with a source address of 0.0.0.0
  net: ll_temac: Avoid ndo_start_xmit returning NETDEV_TX_BUSY
  net: ll_temac: Fix TX BD buffer overwrite
  net: ll_temac: Add memory-barriers for TX BD access
  net: ll_temac: Make sure to free skb when it is completely used
  MAINTAINERS: add Guvenc as SMC maintainer
  bnxt_en: Call bnxt_ethtool_free() in bnxt_init_one() error path
  bnxt_en: Fix TQM fastpath ring backing store computation
  bnxt_en: Rediscover PHY capabilities after firmware reset
  cxgb4: fix wrong shift.
  mac80211: handle various extensible elements correctly
  mac80211: reset profile_periodicity/ema_ap
  cfg80211: avoid double free of PMSR request
  cfg80211: make certificate generation more robust
  mac80211: minstrel_ht: fix sample time check
  net: qed: Fix memcpy() overflow of qed_dcbx_params()
  net: cdc_eem: fix tx fixup skb leak
  net: hamradio: fix memory leak in mkiss_close
  ...
</content>
</entry>
</feed>
