a83829f56c
pvclock_gtod_sync_lock can be taken with interrupts disabled if the preempt notifier calls get_kvmclock_ns to update the Xen runstate information: spin_lock include/linux/spinlock.h:354 [inline] get_kvmclock_ns+0x25/0x390 arch/x86/kvm/x86.c:2587 kvm_xen_update_runstate+0x3d/0x2c0 arch/x86/kvm/xen.c:69 kvm_xen_update_runstate_guest+0x74/0x320 arch/x86/kvm/xen.c:100 kvm_xen_runstate_set_preempted arch/x86/kvm/xen.h:96 [inline] kvm_arch_vcpu_put+0x2d8/0x5a0 arch/x86/kvm/x86.c:4062 So change the users of the spinlock to spin_lock_irqsave and spin_unlock_irqrestore. Reported-by: syzbot+b282b65c2c68492df769@syzkaller.appspotmail.com Fixes: 30b5c851af79 ("KVM: x86/xen: Add support for vCPU runstate information") Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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.