No description
  • C 98.2%
  • Assembly 1%
  • Makefile 0.3%
  • Shell 0.2%
  • Python 0.1%
Find a file
Repository files (latest commit first)
Filename Latest commit message Latest commit date
Juergen Gross a856531951 xen: make xen_qlock_wait() nestable
xen_qlock_wait() isn't safe for nested calls due to interrupts. A call
of xen_qlock_kick() might be ignored in case a deeper nesting level
was active right before the call of xen_poll_irq():

CPU 1:                                   CPU 2:
spin_lock(lock1)
                                         spin_lock(lock1)
                                         -> xen_qlock_wait()
                                            -> xen_clear_irq_pending()
                                            Interrupt happens
spin_unlock(lock1)
-> xen_qlock_kick(CPU 2)
spin_lock_irqsave(lock2)
                                         spin_lock_irqsave(lock2)
                                         -> xen_qlock_wait()
                                            -> xen_clear_irq_pending()
                                               clears kick for lock1
                                            -> xen_poll_irq()
spin_unlock_irq_restore(lock2)
-> xen_qlock_kick(CPU 2)
                                            wakes up
                                         spin_unlock_irq_restore(lock2)
                                         IRET
                                           resumes in xen_qlock_wait()
                                           -> xen_poll_irq()
                                           never wakes up

The solution is to disable interrupts in xen_qlock_wait() and not to
poll for the irq in case xen_qlock_wait() is called in nmi context.

Cc: stable@vger.kernel.org
Cc: Waiman.Long@hp.com
Cc: peterz@infradead.org
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
2018-10-24 10:18:04 +02:00
arch xen: make xen_qlock_wait() nestable 2018-10-24 10:18:04 +02:00
block for-4.20/block-20181021 2018-10-22 17:46:08 +01:00
certs
crypto Revert "net: simplify sock_poll_wait" 2018-10-23 10:57:06 -07:00
Documentation Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-10-24 06:47:44 +01:00
drivers xen/balloon: Grammar s/Is it/It is/ 2018-10-24 10:17:16 +02:00
firmware
fs Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-10-24 06:47:44 +01:00
include Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-10-24 06:47:44 +01:00
init Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 15:00:03 +01:00
ipc
kernel Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-10-24 06:47:44 +01:00
lib Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-10-24 06:47:44 +01:00
LICENSES
mm Merge branch 'x86-mm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 17:05:28 +01:00
net tcp: add tcp_reset_xmit_timer() helper 2018-10-23 19:42:44 -07:00
samples
scripts Merge branch 'parisc-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2018-10-23 20:02:03 +01:00
security
sound Merge branch 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 13:32:18 +01:00
tools Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-10-24 06:47:44 +01:00
usr
virt arm64 updates for 4.20: 2018-10-22 17:30:06 +01:00
.clang-format
.cocciconfig
.get_maintainer.ignore
.gitattributes
.gitignore
.mailmap
COPYING
CREDITS
Kbuild
Kconfig
MAINTAINERS Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2018-10-24 06:47:44 +01:00
Makefile Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-23 13:08:53 +01:00
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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.