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8ba62d3794
Always handle TIF_NOTIFY_SIGNAL in get_signal. With commit 35d0b389f3
("task_work: unconditionally run task_work from get_signal()") always
calling task_work_run all of the work of tracehook_notify_signal is
already happening except clearing TIF_NOTIFY_SIGNAL.
Factor clear_notify_signal out of tracehook_notify_signal and use it in
get_signal so that get_signal only needs one call of task_work_run.
To keep the semantics in sync update xfer_to_guest_mode_work (which
does not call get_signal) to call tracehook_notify_signal if either
_TIF_SIGPENDING or _TIF_NOTIFY_SIGNAL.
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lkml.kernel.org/r/20220309162454.123006-8-ebiederm@xmission.com
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
52 lines
1.2 KiB
C
52 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_SIGPENDING | _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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