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John Donnelly 160c63f909 iommu/vt-d: Fix panic after kexec -p for kdump
This cures a panic on restart after a kexec operation on 5.3 and 5.4
kernels.

The underlying state of the iommu registers (iommu->flags &
VTD_FLAG_TRANS_PRE_ENABLED) on a restart results in a domain being marked as
"DEFER_DEVICE_DOMAIN_INFO" that produces an Oops in identity_mapping().

[   43.654737] BUG: kernel NULL pointer dereference, address:
0000000000000056
[   43.655720] #PF: supervisor read access in kernel mode
[   43.655720] #PF: error_code(0x0000) - not-present page
[   43.655720] PGD 0 P4D 0
[   43.655720] Oops: 0000 [#1] SMP PTI
[   43.655720] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.3.2-1940.el8uek.x86_64 #1
[   43.655720] Hardware name: Oracle Corporation ORACLE SERVER
X5-2/ASM,MOTHERBOARD,1U, BIOS 30140300 09/20/2018
[   43.655720] RIP: 0010:iommu_need_mapping+0x29/0xd0
[   43.655720] Code: 00 0f 1f 44 00 00 48 8b 97 70 02 00 00 48 83 fa ff
74 53 48 8d 4a ff b8 01 00 00 00 48 83 f9 fd 76 01 c3 48 8b 35 7f 58 e0
01 <48> 39 72 58 75 f2 55 48 89 e5 41 54 53 48 8b 87 28 02 00 00 4c 8b
[   43.655720] RSP: 0018:ffffc9000001b9b0 EFLAGS: 00010246
[   43.655720] RAX: 0000000000000001 RBX: 0000000000001000 RCX:
fffffffffffffffd
[   43.655720] RDX: fffffffffffffffe RSI: ffff8880719b8000 RDI:
ffff8880477460b0
[   43.655720] RBP: ffffc9000001b9e8 R08: 0000000000000000 R09:
ffff888047c01700
[   43.655720] R10: 00002194036fc692 R11: 0000000000000000 R12:
0000000000000000
[   43.655720] R13: ffff8880477460b0 R14: 0000000000000cc0 R15:
ffff888072d2b558
[   43.655720] FS:  0000000000000000(0000) GS:ffff888071c00000(0000)
knlGS:0000000000000000
[   43.655720] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   43.655720] CR2: 0000000000000056 CR3: 000000007440a002 CR4:
00000000001606b0
[   43.655720] Call Trace:
[   43.655720]  ? intel_alloc_coherent+0x2a/0x180
[   43.655720]  ? __schedule+0x2c2/0x650
[   43.655720]  dma_alloc_attrs+0x8c/0xd0
[   43.655720]  dma_pool_alloc+0xdf/0x200
[   43.655720]  ehci_qh_alloc+0x58/0x130
[   43.655720]  ehci_setup+0x287/0x7ba
[   43.655720]  ? _dev_info+0x6c/0x83
[   43.655720]  ehci_pci_setup+0x91/0x436
[   43.655720]  usb_add_hcd.cold.48+0x1d4/0x754
[   43.655720]  usb_hcd_pci_probe+0x2bc/0x3f0
[   43.655720]  ehci_pci_probe+0x39/0x40
[   43.655720]  local_pci_probe+0x47/0x80
[   43.655720]  pci_device_probe+0xff/0x1b0
[   43.655720]  really_probe+0xf5/0x3a0
[   43.655720]  driver_probe_device+0xbb/0x100
[   43.655720]  device_driver_attach+0x58/0x60
[   43.655720]  __driver_attach+0x8f/0x150
[   43.655720]  ? device_driver_attach+0x60/0x60
[   43.655720]  bus_for_each_dev+0x74/0xb0
[   43.655720]  driver_attach+0x1e/0x20
[   43.655720]  bus_add_driver+0x151/0x1f0
[   43.655720]  ? ehci_hcd_init+0xb2/0xb2
[   43.655720]  ? do_early_param+0x95/0x95
[   43.655720]  driver_register+0x70/0xc0
[   43.655720]  ? ehci_hcd_init+0xb2/0xb2
[   43.655720]  __pci_register_driver+0x57/0x60
[   43.655720]  ehci_pci_init+0x6a/0x6c
[   43.655720]  do_one_initcall+0x4a/0x1fa
[   43.655720]  ? do_early_param+0x95/0x95
[   43.655720]  kernel_init_freeable+0x1bd/0x262
[   43.655720]  ? rest_init+0xb0/0xb0
[   43.655720]  kernel_init+0xe/0x110
[   43.655720]  ret_from_fork+0x24/0x50

Fixes: 8af46c784e ("iommu/vt-d: Implement is_attach_deferred iommu ops entry")
Cc: stable@vger.kernel.org # v5.3+

Signed-off-by: John Donnelly <john.p.donnelly@oracle.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2019-10-30 10:30:22 +01:00
arch Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-10-27 07:14:40 -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 ARM: SoC fixes 2019-10-25 16:00:47 -04:00
drivers iommu/vt-d: Fix panic after kexec -p for kdump 2019-10-30 10:30:22 +01:00
fs Seven cifs/smb3 fixes, including three for stable 2019-10-27 06:41:52 -04:00
include Driver core fix for 5.4-rc5 2019-10-26 15:23:08 -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 Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-10-27 07:04:22 -04:00
lib lib/vdso: Make clock_getres() POSIX compliant again 2019-10-23 14:48:23 +02:00
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 Modules fixes for v5.4-rc5 2019-10-25 16:11:55 -04:00
security selinux/stable-5.4 PR 20191007 2019-10-08 10:51:37 -07:00
sound ALSA: hda: Add Tigerlake/Jasperlake PCI ID 2019-10-23 06:28:50 +02:00
tools Merge branch 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2019-10-27 06:59:34 -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 #2 2019-10-22 13:31:29 +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 A few MIPS fixes: 2019-10-26 19:43:12 -04:00
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 A few MIPS fixes: 2019-10-26 19:43:12 -04:00
Makefile Linux 5.4-rc5 2019-10-27 13:19:19 -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.