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Gaurav Batra 802b13b79a powerpc/pseries/iommu: LPAR panics during boot up with a frozen PE
[ Upstream commit 49a940dbdc3107fecd5e6d3063dc07128177e058 ]

At the time of LPAR boot up, partition firmware provides Open Firmware
property ibm,dma-window for the PE. This property is provided on the PCI
bus the PE is attached to.

There are execptions where the partition firmware might not provide this
property for the PE at the time of LPAR boot up. One of the scenario is
where the firmware has frozen the PE due to some error condition. This
PE is frozen for 24 hours or unless the whole system is reinitialized.

Within this time frame, if the LPAR is booted, the frozen PE will be
presented to the LPAR but ibm,dma-window property could be missing.

Today, under these circumstances, the LPAR oopses with NULL pointer
dereference, when configuring the PCI bus the PE is attached to.

  BUG: Kernel NULL pointer dereference on read at 0x000000c8
  Faulting instruction address: 0xc0000000001024c0
  Oops: Kernel access of bad area, sig: 7 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  Supported: Yes
  CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.4.0-150600.9-default #1
  Hardware name: IBM,9043-MRX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NM1060_023) hv:phyp pSeries
  NIP:  c0000000001024c0 LR: c0000000001024b0 CTR: c000000000102450
  REGS: c0000000037db5c0 TRAP: 0300   Not tainted  (6.4.0-150600.9-default)
  MSR:  8000000002009033 <SF,VEC,EE,ME,IR,DR,RI,LE>  CR: 28000822  XER: 00000000
  CFAR: c00000000010254c DAR: 00000000000000c8 DSISR: 00080000 IRQMASK: 0
  ...
  NIP [c0000000001024c0] pci_dma_bus_setup_pSeriesLP+0x70/0x2a0
  LR [c0000000001024b0] pci_dma_bus_setup_pSeriesLP+0x60/0x2a0
  Call Trace:
    pci_dma_bus_setup_pSeriesLP+0x60/0x2a0 (unreliable)
    pcibios_setup_bus_self+0x1c0/0x370
    __of_scan_bus+0x2f8/0x330
    pcibios_scan_phb+0x280/0x3d0
    pcibios_init+0x88/0x12c
    do_one_initcall+0x60/0x320
    kernel_init_freeable+0x344/0x3e4
    kernel_init+0x34/0x1d0
    ret_from_kernel_user_thread+0x14/0x1c

Fixes: b1fc44eaa9 ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window")
Signed-off-by: Gaurav Batra <gbatra@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240422205141.10662-1-gbatra@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 12:02:08 +02:00
Documentation mm, treewide: introduce NR_PAGE_ORDERS 2024-05-02 16:32:41 +02:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
arch powerpc/pseries/iommu: LPAR panics during boot up with a frozen PE 2024-05-17 12:02:08 +02:00
block block: fix q->blkg_list corruption during disk rebind 2024-04-17 11:19:28 +02:00
certs certs: Reference revocation list for all keyrings 2023-08-17 20:12:41 +00:00
crypto crypto: jitter - fix CRYPTO_JITTERENTROPY help text 2024-03-26 18:19:52 -04:00
drivers clk: sunxi-ng: h6: Reparent CPUX during PLL CPUX rate change 2024-05-17 12:02:08 +02:00
fs nfs: Handle error of rpc_proc_register() in nfs_net_init(). 2024-05-17 12:01:58 +02:00
include net: gro: fix udp bad offset in socket lookup by adding {inner_}network_offset to napi_gro_cb 2024-05-17 12:02:07 +02:00
init rust: make mutually exclusive with CFI_CLANG 2024-05-02 16:32:42 +02:00
io_uring io_uring: Fix io_cqring_wait() not restoring sigmask on get_timespec64() failure 2024-04-27 17:11:30 +02:00
ipc Add x86 shadow stack support 2023-08-31 12:20:12 -07:00
kernel bpf: Fix a verifier verbose message 2024-05-17 12:02:00 +02:00
lib Fix a potential infinite loop in extract_user_to_sg() 2024-05-17 12:02:02 +02:00
mm mm: turn folio_test_hugetlb into a PageType 2024-05-02 16:32:47 +02:00
net net: gro: add flush check in udp_gro_receive_segment 2024-05-17 12:02:07 +02:00
rust rust: kernel: require `Send` for `Module` implementations 2024-05-17 12:01:56 +02:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-23 09:24:47 +01:00
scripts kbuild: rust: force `alloc` extern to allow "empty" Rust files 2024-05-02 16:32:42 +02:00
security selinux: avoid dereference of garbage after mount failure 2024-04-10 16:35:48 +02:00
sound ALSA: hda: intel-sdw-acpi: fix usage of device_get_named_child_node() 2024-05-17 12:02:05 +02:00
tools selftests/seccomp: Handle EINVAL on unshare(CLONE_NEWPID) 2024-05-02 16:32:42 +02:00
usr initramfs: Encode dependency on KBUILD_BUILD_TIMESTAMP 2023-06-06 17:54:49 +09:00
virt KVM: Always flush async #PF workqueue when vCPU is being destroyed 2024-04-03 15:28:18 +02:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: rename binkernel.spec to kernel.spec 2023-07-25 00:59:33 +09:00
.mailmap 20 hotfixes. 12 are cc:stable and the remainder address post-6.5 issues 2023-10-24 09:52:16 -10:00
.rustfmt.toml rust: add `.rustfmt.toml` 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
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MAINTAINERS ALSA: scarlett2: Rename scarlett_gen2 to scarlett2 2024-04-27 17:11:36 +02:00
Makefile Linux 6.6.30 2024-05-02 16:32:50 +02:00
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.