linux.git/include/linux, branch v5.5-rc5

mm/memory_hotplug: shrink zones when offlining memory

2020-01-04T21:55:08+00:00

We currently try to shrink a single zone when removing memory.  We use
the zone of the first page of the memory we are removing.  If that
memmap was never initialized (e.g., memory was never onlined), we will
read garbage and can trigger kernel BUGs (due to a stale pointer):

    BUG: unable to handle page fault for address: 000000000000353d
    #PF: supervisor write access in kernel mode
    #PF: error_code(0x0002) - not-present page
    PGD 0 P4D 0
    Oops: 0002 [#1] SMP PTI
    CPU: 1 PID: 7 Comm: kworker/u8:0 Not tainted 5.3.0-rc5-next-20190820+ #317
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.4
    Workqueue: kacpi_hotplug acpi_hotplug_work_fn
    RIP: 0010:clear_zone_contiguous+0x5/0x10
    Code: 48 89 c6 48 89 c3 e8 2a fe ff ff 48 85 c0 75 cf 5b 5d c3 c6 85 fd 05 00 00 01 5b 5d c3 0f 1f 840
    RSP: 0018:ffffad2400043c98 EFLAGS: 00010246
    RAX: 0000000000000000 RBX: 0000000200000000 RCX: 0000000000000000
    RDX: 0000000000200000 RSI: 0000000000140000 RDI: 0000000000002f40
    RBP: 0000000140000000 R08: 0000000000000000 R09: 0000000000000001
    R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000140000
    R13: 0000000000140000 R14: 0000000000002f40 R15: ffff9e3e7aff3680
    FS:  0000000000000000(0000) GS:ffff9e3e7bb00000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: 000000000000353d CR3: 0000000058610000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
    Call Trace:
     __remove_pages+0x4b/0x640
     arch_remove_memory+0x63/0x8d
     try_remove_memory+0xdb/0x130
     __remove_memory+0xa/0x11
     acpi_memory_device_remove+0x70/0x100
     acpi_bus_trim+0x55/0x90
     acpi_device_hotplug+0x227/0x3a0
     acpi_hotplug_work_fn+0x1a/0x30
     process_one_work+0x221/0x550
     worker_thread+0x50/0x3b0
     kthread+0x105/0x140
     ret_from_fork+0x3a/0x50
    Modules linked in:
    CR2: 000000000000353d

Instead, shrink the zones when offlining memory or when onlining failed.
Introduce and use remove_pfn_range_from_zone(() for that.  We now
properly shrink the zones, even if we have DIMMs whereby

 - Some memory blocks fall into no zone (never onlined)

 - Some memory blocks fall into multiple zones (offlined+re-onlined)

 - Multiple memory blocks that fall into different zones

Drop the zone parameter (with a potential dubious value) from
__remove_pages() and __remove_section().

Link: http://lkml.kernel.org/r/20191006085646.5768-6-david@redhat.com
Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online")	[visible after d0dc12e86b319]
Signed-off-by: David Hildenbrand 
Reviewed-by: Oscar Salvador 
Cc: Michal Hocko 
Cc: "Matthew Wilcox (Oracle)" 
Cc: "Aneesh Kumar K.V" 
Cc: Pavel Tatashin 
Cc: Greg Kroah-Hartman 
Cc: Dan Williams 
Cc: Logan Gunthorpe 
Cc: 	[5.0+]
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

Merge tag 'dmaengine-fix-5.5-rc5' of git://git.infradead.org/users/vkoul/slave-dma

2020-01-04T18:49:15+00:00

Pull dmaengine fixes from Vinod Koul:
 "A bunch of fixes for:

   - uninitialized dma_slave_caps access

   - virt-dma use after free in vchan_complete()

   - driver fixes for ioat, k3dma and jz4780"

* tag 'dmaengine-fix-5.5-rc5' of git://git.infradead.org/users/vkoul/slave-dma:
  ioat: ioat_alloc_ring() failure handling.
  dmaengine: virt-dma: Fix access after free in vchan_complete()
  dmaengine: k3dma: Avoid null pointer traversal
  dmaengine: dma-jz4780: Also break descriptor chains on JZ4725B
  dmaengine: Fix access to uninitialized dma_slave_caps

Merge tag 'block-5.5-20200103' of git://git.kernel.dk/linux-block

2020-01-03T20:11:30+00:00

Pull block fixes from Jens Axboe:
 "Three fixes in here:

   - Fix for a missing split on default memory boundary mask (4G) (Ming)

   - Fix for multi-page read bio truncate (Ming)

   - Fix for null_blk zone close request handling (Damien)"

* tag 'block-5.5-20200103' of git://git.kernel.dk/linux-block:
  null_blk: Fix REQ_OP_ZONE_CLOSE handling
  block: fix splitting segments on boundary masks
  block: add bio_truncate to fix guard_bio_eod

Merge tag 'sizeof_field-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

2020-01-03T01:04:43+00:00

Pull final sizeof_field conversion from Kees Cook:
 "Remove now unused FIELD_SIZEOF() macro (Kees Cook)"

* tag 'sizeof_field-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  kernel.h: Remove unused FIELD_SIZEOF()

Revert "fs: remove ksys_dup()"

2020-01-03T00:15:33+00:00

This reverts commit 8243186f0cc7 ("fs: remove ksys_dup()") and the
subsequent fix for it in commit 2d3145f8d280 ("early init: fix error
handling when opening /dev/console").

Trying to use filp_open() and f_dupfd() instead of pseudo-syscalls
caused more trouble than what is worth it: it requires accessing vfs
internals and it turns out there were other bugs in it too.

In particular, the file reference counting was wrong - because unlike
the original "open+2*dup" sequence it used "filp_open+3*f_dupfd" and
thus had an extra leaked file reference.

That in turn then caused odd problems with Androidx86 long after boot
becaue of how the extra reference to the console kept the session active
even after all file descriptors had been closed.

Reported-by: youling 257 
Cc: Arvind Sankar 
Cc: Al Viro 
Signed-off-by: Dominik Brodowski 
Signed-off-by: Linus Torvalds

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

2019-12-31T19:14:58+00:00

Pull networking fixes from David Miller:

 1) Fix big endian overflow in nf_flow_table, from Arnd Bergmann.

 2) Fix port selection on big endian in nft_tproxy, from Phil Sutter.

 3) Fix precision tracking for unbound scalars in bpf verifier, from
    Daniel Borkmann.

 4) Fix integer overflow in socket rcvbuf check in UDP, from Antonio
    Messina.

 5) Do not perform a neigh confirmation during a pmtu update over a
    tunnel, from Hangbin Liu.

 6) Fix DMA mapping leak in dpaa_eth driver, from Madalin Bucur.

 7) Various PTP fixes for sja1105 dsa driver, from Vladimir Oltean.

 8) Add missing to dummy definition of of_mdiobus_child_is_phy(), from
    Geert Uytterhoeven

* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (54 commits)
  hsr: fix slab-out-of-bounds Read in hsr_debugfs_rename()
  net/sched: add delete_empty() to filters and use it in cls_flower
  tcp: Fix highest_sack and highest_sack_seq
  ptp: fix the race between the release of ptp_clock and cdev
  net: dsa: sja1105: Reconcile the meaning of TPID and TPID2 for E/T and P/Q/R/S
  Documentation: net: dsa: sja1105: Remove text about taprio base-time limitation
  net: dsa: sja1105: Remove restriction of zero base-time for taprio offload
  net: dsa: sja1105: Really make the PTP command read-write
  net: dsa: sja1105: Take PTP egress timestamp by port, not mgmt slot
  cxgb4/cxgb4vf: fix flow control display for auto negotiation
  mlxsw: spectrum: Use dedicated policer for VRRP packets
  mlxsw: spectrum_router: Skip loopback RIFs during MAC validation
  net: stmmac: dwmac-meson8b: Fix the RGMII TX delay on Meson8b/8m2 SoCs
  net/sched: act_mirred: Pull mac prior redir to non mac_header_xmit device
  net_sched: sch_fq: properly set sk->sk_pacing_status
  bnx2x: Fix accounting of vlan resources among the PFs
  bnx2x: Use appropriate define for vlan credit
  of: mdio: Add missing inline to of_mdiobus_child_is_phy() dummy
  net: phy: aquantia: add suspend / resume ops for AQR105
  dpaa_eth: fix DMA mapping leak
  ...

ptp: fix the race between the release of ptp_clock and cdev

2019-12-31T04:19:27+00:00

In a case when a ptp chardev (like /dev/ptp0) is open but an underlying
device is removed, closing this file leads to a race. This reproduces
easily in a kvm virtual machine:

ts# cat openptp0.c
int main() { ... fp = fopen("/dev/ptp0", "r"); ... sleep(10); }
ts# uname -r
5.5.0-rc3-46cf053e
ts# cat /proc/cmdline
... slub_debug=FZP
ts# modprobe ptp_kvm
ts# ./openptp0 &
[1] 670
opened /dev/ptp0, sleeping 10s...
ts# rmmod ptp_kvm
ts# ls /dev/ptp*
ls: cannot access '/dev/ptp*': No such file or directory
ts# ...woken up
[   48.010809] general protection fault: 0000 [#1] SMP
[   48.012502] CPU: 6 PID: 658 Comm: openptp0 Not tainted 5.5.0-rc3-46cf053e #25
[   48.014624] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), ...
[   48.016270] RIP: 0010:module_put.part.0+0x7/0x80
[   48.017939] RSP: 0018:ffffb3850073be00 EFLAGS: 00010202
[   48.018339] RAX: 000000006b6b6b6b RBX: 6b6b6b6b6b6b6b6b RCX: ffff89a476c00ad0
[   48.018936] RDX: fffff65a08d3ea08 RSI: 0000000000000247 RDI: 6b6b6b6b6b6b6b6b
[   48.019470] ...                                              ^^^ a slub poison
[   48.023854] Call Trace:
[   48.024050]  __fput+0x21f/0x240
[   48.024288]  task_work_run+0x79/0x90
[   48.024555]  do_exit+0x2af/0xab0
[   48.024799]  ? vfs_write+0x16a/0x190
[   48.025082]  do_group_exit+0x35/0x90
[   48.025387]  __x64_sys_exit_group+0xf/0x10
[   48.025737]  do_syscall_64+0x3d/0x130
[   48.026056]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
[   48.026479] RIP: 0033:0x7f53b12082f6
[   48.026792] ...
[   48.030945] Modules linked in: ptp i6300esb watchdog [last unloaded: ptp_kvm]
[   48.045001] Fixing recursive fault but reboot is needed!

This happens in:

static void __fput(struct file *file)
{   ...
    if (file->f_op->release)
        file->f_op->release(inode, file); <<< cdev is kfree'd here
    if (unlikely(S_ISCHR(inode->i_mode) && inode->i_cdev != NULL &&
             !(mode & FMODE_PATH))) {
        cdev_put(inode->i_cdev); <<< cdev fields are accessed here

Namely:

__fput()
  posix_clock_release()
    kref_put(&clk->kref, delete_clock) <<< the last reference
      delete_clock()
        delete_ptp_clock()
          kfree(ptp) <<< cdev is embedded in ptp
  cdev_put
    module_put(p->owner) <<< *p is kfree'd, bang!

Here cdev is embedded in posix_clock which is embedded in ptp_clock.
The race happens because ptp_clock's lifetime is controlled by two
refcounts: kref and cdev.kobj in posix_clock. This is wrong.

Make ptp_clock's sysfs device a parent of cdev with cdev_device_add()
created especially for such cases. This way the parent device with its
ptp_clock is not released until all references to the cdev are released.
This adds a requirement that an initialized but not exposed struct
device should be provided to posix_clock_register() by a caller instead
of a simple dev_t.

This approach was adopted from the commit 72139dfa2464 ("watchdog: Fix
the race between the release of watchdog_core_data and cdev"). See
details of the implementation in the commit 233ed09d7fda ("chardev: add
helper function to register char devs with a struct device").

Link: https://lore.kernel.org/linux-fsdevel/20191125125342.6189-1-vdronov@redhat.com/T/#u
Analyzed-by: Stephen Johnston 
Analyzed-by: Vern Lovejoy 
Signed-off-by: Vladis Dronov 
Acked-by: Richard Cochran 
Signed-off-by: David S. Miller

kernel.h: Remove unused FIELD_SIZEOF()

2019-12-30T20:01:56+00:00

Now that all callers of FIELD_SIZEOF() have been converted to
sizeof_field(), remove the unused prior macro.

Signed-off-by: Kees Cook

block: add bio_truncate to fix guard_bio_eod

2019-12-28T16:44:56+00:00

Some filesystem, such as vfat, may send bio which crosses device boundary,
and the worse thing is that the IO request starting within device boundaries
can contain more than one segment past EOD.

Commit dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors")
tries to fix this issue by returning -EIO for this situation. However,
this way lets fs user code lose chance to handle -EIO, then sync_inodes_sb()
may hang for ever.

Also the current truncating on last segment is dangerous by updating the
last bvec, given bvec table becomes not immutable any more, and fs bio
users may not retrieve the truncated pages via bio_for_each_segment_all() in
its .end_io callback.

Fixes this issue by supporting multi-segment truncating. And the
approach is simpler:

- just update bio size since block layer can make correct bvec with
the updated bio size. Then bvec table becomes really immutable.

- zero all truncated segments for read bio

Cc: Carlos Maiolino 
Cc: linux-fsdevel@vger.kernel.org
Fixed-by: dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors")
Reported-by: syzbot+2b9e54155c8c25d8d165@syzkaller.appspotmail.com
Signed-off-by: Ming Lei 
Signed-off-by: Jens Axboe

of: mdio: Add missing inline to of_mdiobus_child_is_phy() dummy

2019-12-26T23:17:26+00:00

If CONFIG_OF_MDIO=n:

    drivers/net/phy/mdio_bus.c:23:
    include/linux/of_mdio.h:58:13: warning: ‘of_mdiobus_child_is_phy’ defined but not used [-Wunused-function]
     static bool of_mdiobus_child_is_phy(struct device_node *child)
		 ^~~~~~~~~~~~~~~~~~~~~~~

Fix this by adding the missing "inline" keyword.

Fixes: 0aa4d016c043d16a ("of: mdio: export of_mdiobus_child_is_phy")
Signed-off-by: Geert Uytterhoeven 
Reviewed-by: Andrew Lunn 
Acked-by: Borislav Petkov 
Signed-off-by: David S. Miller