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Jason Gunthorpe 1524b12a6e RDMA/mlx5: Use irq xarray locking for mkey_table
The mkey_table xarray is touched by the reg_mr_callback() function which
is called from a hard irq. Thus all other uses of xa_lock must use the
_irq variants.

  WARNING: inconsistent lock state
  5.4.0-rc1 #12 Not tainted
  --------------------------------
  inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage.
  python3/343 [HC0[0]:SC0[0]:HE1:SE1] takes:
  ffff888182be1d40 (&(&xa->xa_lock)->rlock#3){?.-.}, at: xa_erase+0x12/0x30
  {IN-HARDIRQ-W} state was registered at:
    lock_acquire+0xe1/0x200
    _raw_spin_lock_irqsave+0x35/0x50
    reg_mr_callback+0x2dd/0x450 [mlx5_ib]
    mlx5_cmd_exec_cb_handler+0x2c/0x70 [mlx5_core]
    mlx5_cmd_comp_handler+0x355/0x840 [mlx5_core]
   [..]

   Possible unsafe locking scenario:

         CPU0
         ----
    lock(&(&xa->xa_lock)->rlock#3);
    <Interrupt>
      lock(&(&xa->xa_lock)->rlock#3);

   *** DEADLOCK ***

  2 locks held by python3/343:
   #0: ffff88818eb4bd38 (&uverbs_dev->disassociate_srcu){....}, at: ib_uverbs_ioctl+0xe5/0x1e0 [ib_uverbs]
   #1: ffff888176c76d38 (&file->hw_destroy_rwsem){++++}, at: uobj_destroy+0x2d/0x90 [ib_uverbs]

  stack backtrace:
  CPU: 3 PID: 343 Comm: python3 Not tainted 5.4.0-rc1 #12
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
  Call Trace:
   dump_stack+0x86/0xca
   print_usage_bug.cold.50+0x2e5/0x355
   mark_lock+0x871/0xb50
   ? match_held_lock+0x20/0x250
   ? check_usage_forwards+0x240/0x240
   __lock_acquire+0x7de/0x23a0
   ? __kasan_check_read+0x11/0x20
   ? mark_lock+0xae/0xb50
   ? mark_held_locks+0xb0/0xb0
   ? find_held_lock+0xca/0xf0
   lock_acquire+0xe1/0x200
   ? xa_erase+0x12/0x30
   _raw_spin_lock+0x2a/0x40
   ? xa_erase+0x12/0x30
   xa_erase+0x12/0x30
   mlx5_ib_dealloc_mw+0x55/0xa0 [mlx5_ib]
   uverbs_dealloc_mw+0x3c/0x70 [ib_uverbs]
   uverbs_free_mw+0x1a/0x20 [ib_uverbs]
   destroy_hw_idr_uobject+0x49/0xa0 [ib_uverbs]
   [..]

Fixes: 0417791536 ("RDMA/mlx5: Add missing synchronize_srcu() for MW cases")
Link: https://lore.kernel.org/r/20191024234910.GA9038@ziepe.ca
Acked-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2019-10-28 14:08:48 -03:00
Documentation Documentation/process update for 5.4-rc1 2019-09-29 19:52:52 -07:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
arch csky-for-linus-5.4-rc1: arch/csky patches for 5.4-rc1 2019-09-30 10:16:17 -07:00
block block: fix null pointer dereference in blk_mq_rq_timed_out() 2019-09-27 07:01:25 -06:00
certs PKCS#7: Refactor verify_pkcs7_signature() 2019-08-05 18:40:18 -04:00
crypto Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
drivers RDMA/mlx5: Use irq xarray locking for mkey_table 2019-10-28 14:08:48 -03:00
fs for-5.4-rc1-tag 2019-09-30 10:25:24 -07:00
include RDMA/uverbs: Prevent potential underflow 2019-10-22 15:05:36 -03:00
init Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
ipc ipc/sem.c: convert to use built-in RCU list checking 2019-09-25 17:51:41 -07:00
kernel A few more tracing fixes: 2019-09-30 09:29:53 -07:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-28 17:47:33 -07:00
mm Merge branch 'hugepage-fallbacks' (hugepatch patches from David Rientjes) 2019-09-28 14:26:47 -07:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-28 17:47:33 -07:00
samples rpmsg updates for v5.4 2019-09-22 10:58:15 -07:00
scripts Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2019-09-27 19:37:27 -07:00
security Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2019-09-28 08:14:15 -07:00
sound sound fixes for 5.4-rc1 2019-09-24 16:46:16 -07:00
tools A few more tracing fixes: 2019-09-30 09:29:53 -07:00
usr Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-09-28 17:47:33 -07:00
virt * s390: ioctl hardening, selftests 2019-09-18 09:49:13 -07:00
.clang-format clang-format: Update with the latest for_each macro list 2019-08-31 10:00:51 +02:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes
.gitignore Modules updates for v5.4 2019-09-22 10:34:46 -07:00
.mailmap Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next 2019-09-18 12:34:53 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS CREDITS: Update email address 2019-09-13 17:21:38 +03:00
Kbuild kbuild: do not descend to ./Kbuild when cleaning 2019-08-21 21:03:58 +09:00
Kconfig docs: kbuild: convert docs to ReST and rename to *.rst 2019-06-14 14:21:21 -06:00
MAINTAINERS ARM SCMI fixes for v5.4 2019-09-29 11:20:41 -07:00
Makefile Linux 5.4-rc1 2019-09-30 10:35:40 -07:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

README

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.