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John Garry 130f4caf14 libata: Ensure ata_port probe has completed before detach
With CONFIG_DEBUG_TEST_DRIVER_REMOVE set, we may find the following WARN:

[   23.452574] ------------[ cut here ]------------
[   23.457190] WARNING: CPU: 59 PID: 1 at drivers/ata/libata-core.c:6676 ata_host_detach+0x15c/0x168
[   23.466047] Modules linked in:
[   23.469092] CPU: 59 PID: 1 Comm: swapper/0 Not tainted 5.4.0-rc1-00010-g5b83fd27752b-dirty #296
[   23.477776] Hardware name: Huawei D06 /D06, BIOS Hisilicon D06 UEFI RC0 - V1.16.01 03/15/2019
[   23.486286] pstate: a0c00009 (NzCv daif +PAN +UAO)
[   23.491065] pc : ata_host_detach+0x15c/0x168
[   23.495322] lr : ata_host_detach+0x88/0x168
[   23.499491] sp : ffff800011cabb50
[   23.502792] x29: ffff800011cabb50 x28: 0000000000000007
[   23.508091] x27: ffff80001137f068 x26: ffff8000112c0c28
[   23.513390] x25: 0000000000003848 x24: ffff0023ea185300
[   23.518689] x23: 0000000000000001 x22: 00000000000014c0
[   23.523987] x21: 0000000000013740 x20: ffff0023bdc20000
[   23.529286] x19: 0000000000000000 x18: 0000000000000004
[   23.534584] x17: 0000000000000001 x16: 00000000000000f0
[   23.539883] x15: ffff0023eac13790 x14: ffff0023eb76c408
[   23.545181] x13: 0000000000000000 x12: ffff0023eac13790
[   23.550480] x11: ffff0023eb76c228 x10: 0000000000000000
[   23.555779] x9 : ffff0023eac13798 x8 : 0000000040000000
[   23.561077] x7 : 0000000000000002 x6 : 0000000000000001
[   23.566376] x5 : 0000000000000002 x4 : 0000000000000000
[   23.571674] x3 : ffff0023bf08a0bc x2 : 0000000000000000
[   23.576972] x1 : 3099674201f72700 x0 : 0000000000400284
[   23.582272] Call trace:
[   23.584706]  ata_host_detach+0x15c/0x168
[   23.588616]  ata_pci_remove_one+0x10/0x18
[   23.592615]  ahci_remove_one+0x20/0x40
[   23.596356]  pci_device_remove+0x3c/0xe0
[   23.600267]  really_probe+0xdc/0x3e0
[   23.603830]  driver_probe_device+0x58/0x100
[   23.608000]  device_driver_attach+0x6c/0x90
[   23.612169]  __driver_attach+0x84/0xc8
[   23.615908]  bus_for_each_dev+0x74/0xc8
[   23.619730]  driver_attach+0x20/0x28
[   23.623292]  bus_add_driver+0x148/0x1f0
[   23.627115]  driver_register+0x60/0x110
[   23.630938]  __pci_register_driver+0x40/0x48
[   23.635199]  ahci_pci_driver_init+0x20/0x28
[   23.639372]  do_one_initcall+0x5c/0x1b0
[   23.643199]  kernel_init_freeable+0x1a4/0x24c
[   23.647546]  kernel_init+0x10/0x108
[   23.651023]  ret_from_fork+0x10/0x18
[   23.654590] ---[ end trace 634a14b675b71c13 ]---

With KASAN also enabled, we may also get many use-after-free reports.

The issue is that when CONFIG_DEBUG_TEST_DRIVER_REMOVE is set, we may
attempt to detach the ata_port before it has been probed.

This is because the ata_ports are async probed, meaning that there is no
guarantee that the ata_port has probed prior to detach. When the ata_port
does probe in this scenario, we get all sorts of issues as the detach may
have already happened.

Fix by ensuring synchronisation with async_synchronize_full(). We could
alternatively use the cookie returned from the ata_port probe
async_schedule() call, but that means managing the cookie, so more
complicated.

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-31 13:18:54 -06:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-10-20 06:31:14 -04:00
block blk-rq-qos: fix first node deletion of rq_qos_del() 2019-10-15 10:13:13 -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
Documentation Merge branch 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-10-20 06:27:54 -04:00
drivers libata: Ensure ata_port probe has completed before detach 2019-10-31 13:18:54 -06:00
fs Merge branch 'akpm' (patches from Andrew) 2019-10-19 06:53:59 -04:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
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 Kbuild fixes for v5.4 (2nd) 2019-10-20 12:36:57 -04:00
lib copy-struct-from-user-v5.4-rc4 2019-10-18 18:19:04 -04:00
LICENSES LICENSES: Rename other to deprecated 2019-05-03 06:34:32 -06:00
mm mm/thp: allow dropping THP from page cache 2019-10-19 06:32:33 -04:00
net Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
samples samples/bpf: Add a workaround for asm_inline 2019-10-03 17:37:11 +02:00
scripts Kbuild fixes for v5.4 (2nd) 2019-10-20 12:36:57 -04:00
security selinux/stable-5.4 PR 20191007 2019-10-08 10:51:37 -07:00
sound ALSA: hda - Force runtime PM on Nvidia HDMI codecs 2019-10-17 17:45:32 +02:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
usr kbuild: update compile-test header list for v5.4-rc2 2019-10-05 15:29:49 +09:00
virt KVM/arm fixes for 5.4, take #1 2019-10-03 12:08:50 +02:00
.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 .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.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 MAINTAINERS: Remove Simon as Renesas SoC Co-Maintainer 2019-10-10 08:12:51 -07:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2019-10-19 17:09:11 -04:00
Makefile Linux 5.4-rc4 2019-10-20 15:56:22 -04:00
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.