KVM: arm64: vgic: Don't acquire its_lock before config_lock

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commit 49e5d16b6f upstream.

commit f003277311 ("KVM: arm64: Use config_lock to protect vgic
state") was meant to rectify a longstanding lock ordering issue in KVM
where the kvm->lock is taken while holding vcpu->mutex. As it so
happens, the aforementioned commit introduced yet another locking issue
by acquiring the its_lock before acquiring the config lock.

This is obviously wrong, especially considering that the lock ordering
is well documented in vgic.c. Reshuffle the locks once more to take the
config_lock before the its_lock. While at it, sprinkle in the lockdep
hinting that has become popular as of late to keep lockdep apprised of
our ordering.

Cc: stable@vger.kernel.org
Fixes: f003277311 ("KVM: arm64: Use config_lock to protect vgic state")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230412062733.988229-1-oliver.upton@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

...

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Oliver Upton 2023-04-12 06:27:33 +00:00 • committed by Greg Kroah-Hartman

parent 569f33c3c2

commit 5bd77c2393

1 changed files with 12 additions and 3 deletions

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arch/arm64/kvm/vgic/vgic-its.c

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