KVM: arm64: Return early from trace helpers when KVM isn't available

Browse source

When Linux is booted at EL1, host_data_ptr() resolves to the nVHE
hypervisor's copy of host data. When hyp mode isn't available for
KVM the nVHE percpu bases remain uninitialized. Consequently, any usage
of host_data_ptr() will result in a NULL dereference which has been
observed in KVM's trace filtering helpers.

Add an early return to the trace filtering helpers if KVM isn't
initialized, avoiding the NULL dereference. Take this opportunity
to move the TRBE-skipping checks to a common helper.

Fixes: 054b88391b ("KVM: arm64: Support trace filtering for guests")
Signed-off-by: Yingchao Deng <yingchao.deng@oss.qualcomm.com>
Reviewed-by: James Clark <james.clark@linaro.org>
[maz: repainted the helpers to be readable, and the commit message
 with Oliver's suggestion]
Signed-off-by: Marc Zyngier <maz@kernel.org>

...

This commit is contained in:

Yingchao Deng 2025-09-02 11:48:25 +08:00 • committed by Marc Zyngier

parent 2ba972bf71

commit 27d2b47eef

1 changed files with 11 additions and 11 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

22

arch/arm64/kvm/debug.c

View file