leandrof/linux
1
0
Fork 0
forked from Minki/linux
Code Issues Pull Requests Packages Projects Releases Wiki Activity
mainlining shenanigans
1,088,633 Commits 2 Branches 0 Tags 5.1 GiB
C 97.7%
Assembly 1.1%
Shell 0.4%
Makefile 0.3%
Python 0.2%
Other 0.1%
19bef63f95
Go to file
Prakruthi Deepak Heragu 19bef63f95 arm64: paravirt: Use RCU read locks to guard stolen_time 
During hotplug, the stolen time data structure is unmapped and memset.
There is a possibility of the timer IRQ being triggered before memset
and stolen time is getting updated as part of this timer IRQ handler. This
causes the below crash in timer handler -

  [ 3457.473139][    C5] Unable to handle kernel paging request at virtual address ffffffc03df05148
  ...
  [ 3458.154398][    C5] Call trace:
  [ 3458.157648][    C5]  para_steal_clock+0x30/0x50
  [ 3458.162319][    C5]  irqtime_account_process_tick+0x30/0x194
  [ 3458.168148][    C5]  account_process_tick+0x3c/0x280
  [ 3458.173274][    C5]  update_process_times+0x5c/0xf4
  [ 3458.178311][    C5]  tick_sched_timer+0x180/0x384
  [ 3458.183164][    C5]  __run_hrtimer+0x160/0x57c
  [ 3458.187744][    C5]  hrtimer_interrupt+0x258/0x684
  [ 3458.192698][    C5]  arch_timer_handler_virt+0x5c/0xa0
  [ 3458.198002][    C5]  handle_percpu_devid_irq+0xdc/0x414
  [ 3458.203385][    C5]  handle_domain_irq+0xa8/0x168
  [ 3458.208241][    C5]  gic_handle_irq.34493+0x54/0x244
  [ 3458.213359][    C5]  call_on_irq_stack+0x40/0x70
  [ 3458.218125][    C5]  do_interrupt_handler+0x60/0x9c
  [ 3458.223156][    C5]  el1_interrupt+0x34/0x64
  [ 3458.227560][    C5]  el1h_64_irq_handler+0x1c/0x2c
  [ 3458.232503][    C5]  el1h_64_irq+0x7c/0x80
  [ 3458.236736][    C5]  free_vmap_area_noflush+0x108/0x39c
  [ 3458.242126][    C5]  remove_vm_area+0xbc/0x118
  [ 3458.246714][    C5]  vm_remove_mappings+0x48/0x2a4
  [ 3458.251656][    C5]  __vunmap+0x154/0x278
  [ 3458.255796][    C5]  stolen_time_cpu_down_prepare+0xc0/0xd8
  [ 3458.261542][    C5]  cpuhp_invoke_callback+0x248/0xc34
  [ 3458.266842][    C5]  cpuhp_thread_fun+0x1c4/0x248
  [ 3458.271696][    C5]  smpboot_thread_fn+0x1b0/0x400
  [ 3458.276638][    C5]  kthread+0x17c/0x1e0
  [ 3458.280691][    C5]  ret_from_fork+0x10/0x20

As a fix, introduce rcu lock to update stolen time structure.

Fixes: 75df529bec ("arm64: paravirt: Initialize steal time when cpu is online")
Cc: stable@vger.kernel.org
Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Prakruthi Deepak Heragu <quic_pheragu@quicinc.com>
Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
Reviewed-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Link: https://lore.kernel.org/r/20220513174654.362169-1-quic_eberman@quicinc.com
Signed-off-by: Will Deacon <will@kernel.org>
2022-05-17 14:23:37 +01:00
arch arm64: paravirt: Use RCU read locks to guard stolen_time 2022-05-17 14:23:37 +01:00
block for-5.18/block-2022-04-01 2022-04-01 16:20:00 -07:00
certs Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
crypto for-5.18/64bit-pi-2022-03-25 2022-03-26 12:01:35 -07:00
Documentation arm64: Enable repeat tlbi workaround on KRYO4XX gold CPUs 2022-05-12 13:15:38 +01:00
drivers arm_pmu: Validate single/group leader events 2022-04-13 11:48:45 +01:00
fs Updates to Tracing: 2022-04-03 12:26:01 -07:00
include elf: Fix the arm64 MTE ELF segment name and value 2022-04-28 11:37:06 +01:00
init Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
ipc fs: allocate inode by using alloc_inode_sb() 2022-03-22 15:57:03 -07:00
kernel Updates to Tracing: 2022-04-03 12:26:01 -07:00
lib for-5.18/block-2022-04-01 2022-04-01 16:20:00 -07:00
LICENSES LICENSES/LGPL-2.1: Add LGPL-2.1-or-later as valid identifiers 2021-12-16 14:33:10 +01:00
mm Filesystem/VFS changes for 5.18, part two 2022-04-01 13:50:50 -07:00
net Networking fixes for 5.18-rc1 and rethook patches. 2022-03-31 11:23:31 -07:00
samples dma-mapping updates for Linux 5.18 2022-03-29 08:50:14 -07:00
scripts modpost: restore the warning message for missing symbol versions 2022-04-03 03:11:51 +09:00
security hardening updates for v5.18-rc1-fix1 2022-03-31 11:43:01 -07:00
sound sound fixes for 5.18-rc1 2022-04-01 10:32:46 -07:00
tools A set of x86 fixes and updates: 2022-04-03 12:15:47 -07:00
usr Kbuild updates for v5.18 2022-03-31 11:59:03 -07:00
virt KVM: Remove dirty handling from gfn_to_pfn_cache completely 2022-04-02 05:34:41 -04:00
.clang-format genirq/msi: Make interrupt allocation less convoluted 2021-12-16 22:22:20 +01:00
.cocciconfig
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: update Kirill's email 2022-04-01 11:46:09 -07:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: replace a Microchip AT91 maintainer 2022-02-09 11:30:01 +01:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS chrome platform changes for 5.18 2022-04-02 10:44:18 -07:00
Makefile Linux 5.18-rc1 2022-04-03 14:08:21 -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.