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6ce895128b
Some thread flags can be set remotely, and so even when IRQs are disabled, the flags can change under our feet. Generally this is unlikely to cause a problem in practice, but it is somewhat unsound, and KCSAN will legitimately warn that there is a data race. To avoid such issues, a snapshot of the flags has to be taken prior to using them. Some places already use READ_ONCE() for that, others do not. Convert them all to the new flag accessor helpers. Signed-off-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Paul E. McKenney <paulmck@kernel.org> Link: https://lore.kernel.org/r/20211129130653.2037928-3-mark.rutland@arm.com
53 lines
1.2 KiB
C
53 lines
1.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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#include <linux/entry-kvm.h>
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#include <linux/kvm_host.h>
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static int xfer_to_guest_mode_work(struct kvm_vcpu *vcpu, unsigned long ti_work)
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{
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do {
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int ret;
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if (ti_work & _TIF_NOTIFY_SIGNAL)
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tracehook_notify_signal();
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if (ti_work & _TIF_SIGPENDING) {
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kvm_handle_signal_exit(vcpu);
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return -EINTR;
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}
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if (ti_work & _TIF_NEED_RESCHED)
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schedule();
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if (ti_work & _TIF_NOTIFY_RESUME)
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tracehook_notify_resume(NULL);
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ret = arch_xfer_to_guest_mode_handle_work(vcpu, ti_work);
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if (ret)
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return ret;
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ti_work = read_thread_flags();
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} while (ti_work & XFER_TO_GUEST_MODE_WORK || need_resched());
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return 0;
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}
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int xfer_to_guest_mode_handle_work(struct kvm_vcpu *vcpu)
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{
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unsigned long ti_work;
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/*
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* This is invoked from the outer guest loop with interrupts and
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* preemption enabled.
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*
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* KVM invokes xfer_to_guest_mode_work_pending() with interrupts
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* disabled in the inner loop before going into guest mode. No need
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* to disable interrupts here.
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*/
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ti_work = read_thread_flags();
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if (!(ti_work & XFER_TO_GUEST_MODE_WORK))
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return 0;
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return xfer_to_guest_mode_work(vcpu, ti_work);
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}
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EXPORT_SYMBOL_GPL(xfer_to_guest_mode_handle_work);
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