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Willem de Bruijn 001e465f09 bonding: update nest level on unlink
A network device stack with multiple layers of bonding devices can
trigger a false positive lockdep warning. Adding lockdep nest levels
fixes this. Update the level on both enslave and unlink, to avoid the
following series of events ..

    ip netns add test
    ip netns exec test bash
    ip link set dev lo addr 00:11:22:33:44:55
    ip link set dev lo down

    ip link add dev bond1 type bond
    ip link add dev bond2 type bond

    ip link set dev lo master bond1
    ip link set dev bond1 master bond2

    ip link set dev bond1 nomaster
    ip link set dev bond2 master bond1

.. from still generating a splat:

    [  193.652127] ======================================================
    [  193.658231] WARNING: possible circular locking dependency detected
    [  193.664350] 4.20.0 #8 Not tainted
    [  193.668310] ------------------------------------------------------
    [  193.674417] ip/15577 is trying to acquire lock:
    [  193.678897] 00000000a40e3b69 (&(&bond->stats_lock)->rlock#3/3){+.+.}, at: bond_get_stats+0x58/0x290
    [  193.687851]
    	       but task is already holding lock:
    [  193.693625] 00000000807b9d9f (&(&bond->stats_lock)->rlock#2/2){+.+.}, at: bond_get_stats+0x58/0x290

    [..]

    [  193.851092]        lock_acquire+0xa7/0x190
    [  193.855138]        _raw_spin_lock_nested+0x2d/0x40
    [  193.859878]        bond_get_stats+0x58/0x290
    [  193.864093]        dev_get_stats+0x5a/0xc0
    [  193.868140]        bond_get_stats+0x105/0x290
    [  193.872444]        dev_get_stats+0x5a/0xc0
    [  193.876493]        rtnl_fill_stats+0x40/0x130
    [  193.880797]        rtnl_fill_ifinfo+0x6c5/0xdc0
    [  193.885271]        rtmsg_ifinfo_build_skb+0x86/0xe0
    [  193.890091]        rtnetlink_event+0x5b/0xa0
    [  193.894320]        raw_notifier_call_chain+0x43/0x60
    [  193.899225]        netdev_change_features+0x50/0xa0
    [  193.904044]        bond_compute_features.isra.46+0x1ab/0x270
    [  193.909640]        bond_enslave+0x141d/0x15b0
    [  193.913946]        do_set_master+0x89/0xa0
    [  193.918016]        do_setlink+0x37c/0xda0
    [  193.921980]        __rtnl_newlink+0x499/0x890
    [  193.926281]        rtnl_newlink+0x48/0x70
    [  193.930238]        rtnetlink_rcv_msg+0x171/0x4b0
    [  193.934801]        netlink_rcv_skb+0xd1/0x110
    [  193.939103]        rtnetlink_rcv+0x15/0x20
    [  193.943151]        netlink_unicast+0x3b5/0x520
    [  193.947544]        netlink_sendmsg+0x2fd/0x3f0
    [  193.951942]        sock_sendmsg+0x38/0x50
    [  193.955899]        ___sys_sendmsg+0x2ba/0x2d0
    [  193.960205]        __x64_sys_sendmsg+0xad/0x100
    [  193.964687]        do_syscall_64+0x5a/0x460
    [  193.968823]        entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 7e2556e400 ("bonding: avoid lockdep confusion in bond_get_stats()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-01-10 16:49:39 -05:00
arch Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
block for-4.21/block-20190102 2019-01-02 18:49:58 -08:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto Kconfig updates for v4.21 2018-12-29 13:03:29 -08:00
Documentation bpf, doc: update design qa to reflect kern_version requirement 2019-01-07 15:52:00 -08:00
drivers bonding: update nest level on unlink 2019-01-10 16:49:39 -05:00
firmware firmware: refactor firmware/Makefile 2018-12-23 10:10:32 +09:00
fs Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
include ptp: uapi: change _IOW to IOWR in PTP_SYS_OFFSET_EXTENDED definition 2019-01-08 16:22:56 -05:00
init Merge tag 'devicetree-for-4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux 2018-12-28 20:08:34 -08:00
ipc ipc: IPCMNI limit check for semmni 2018-10-31 08:54:14 -07:00
kernel bpf: fix sanitation of alu op with pointer / scalar type from different paths 2019-01-05 21:32:38 -08:00
lib Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
LICENSES This is a fairly typical cycle for documentation. There's some welcome 2018-10-24 18:01:11 +01:00
mm Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
net ipv6: fix kernel-infoleak in ipv6_local_error() 2019-01-10 09:36:41 -05:00
samples selftests/bpf: fix incorrect users of create_and_get_cgroup 2019-01-07 13:15:55 -08:00
scripts Tracing changes for v4.21: 2018-12-31 11:46:59 -08:00
security Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
sound Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
tools selftests: forwarding: Add a test for VLAN deletion 2019-01-08 16:53:54 -05:00
usr user/Makefile: Fix typo and capitalization in comment section 2018-12-11 00:18:03 +09:00
virt Remove 'type' argument from access_ok() function 2019-01-03 18:57:57 -08:00
.clang-format page cache: Convert find_get_pages_contig to XArray 2018-10-21 10:46:34 -04:00
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.gitignore kbuild: Add support for DT binding schema checks 2018-12-13 09:41:32 -06:00
.mailmap Merge tag 'nand/for-4.21' of git://git.infradead.org/linux-mtd into mtd/next 2018-12-18 19:59:16 +01:00
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Kbuild kbuild: remove unused cmd_gentimeconst 2018-12-25 00:10:30 +09:00
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MAINTAINERS Merge branch 'for-linus-4.21-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2019-01-02 18:39:22 -08:00
Makefile Kbuild updates for v4.21 2018-12-29 12:03:17 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.