From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001
From: Fuad Tabba <fuad.tabba@linux.dev>
Date: Tue, 22 Sep 2026 19:14:30 +0100
Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2

__init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2.
PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in
HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host
traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The
kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU
driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a
write from EL0 reaches the trap and takes the host down without a panic
message.

Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already
does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9
bits.

Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9")
Cc: stable@vger.kernel.org
Signed-off-by: Fuad Tabba <fuad.tabba@linux.dev>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Oliver Upton <oupton@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
---
 scripts/selinux/install_policy.sh | 81 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 81 insertions(+)
 create mode 100755 scripts/selinux/install_policy.sh

(limited to 'scripts/selinux/install_policy.sh')

diff --git a/scripts/selinux/install_policy.sh b/scripts/selinux/install_policy.sh
new file mode 100755
index 000000000..77368a73f
--- /dev/null
+++ b/scripts/selinux/install_policy.sh
@@ -0,0 +1,81 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+set -e
+if [ `id -u` -ne 0 ]; then
+	echo "$0: must be root to install the selinux policy"
+	exit 1
+fi
+
+SF=`which setfiles` || {
+	echo "Could not find setfiles"
+	echo "Do you have policycoreutils installed?"
+	exit 1
+}
+
+CP=`which checkpolicy` || {
+	echo "Could not find checkpolicy"
+	echo "Do you have checkpolicy installed?"
+	exit 1
+}
+VERS=`$CP -V | awk '{print $1}'`
+
+ENABLED=`which selinuxenabled` || {
+	echo "Could not find selinuxenabled"
+	echo "Do you have libselinux-utils installed?"
+	exit 1
+}
+
+if selinuxenabled; then
+    echo "SELinux is already enabled"
+    echo "This prevents safely relabeling all files."
+    echo "Boot with selinux=0 on the kernel command-line."
+    exit 1
+fi
+
+cd mdp
+./mdp -m policy.conf file_contexts
+$CP -U allow -M -o policy.$VERS policy.conf
+
+mkdir -p /etc/selinux/dummy/policy
+mkdir -p /etc/selinux/dummy/contexts/files
+
+echo "__default__:user_u:s0" > /etc/selinux/dummy/seusers
+echo "base_r:base_t:s0" > /etc/selinux/dummy/contexts/failsafe_context
+echo "base_r:base_t:s0 base_r:base_t:s0" > /etc/selinux/dummy/default_contexts
+cat > /etc/selinux/dummy/contexts/x_contexts <<EOF
+client * user_u:base_r:base_t:s0
+property * user_u:object_r:base_t:s0
+extension * user_u:object_r:base_t:s0
+selection * user_u:object_r:base_t:s0
+event * user_u:object_r:base_t:s0
+EOF
+touch /etc/selinux/dummy/contexts/virtual_domain_context
+touch /etc/selinux/dummy/contexts/virtual_image_context
+
+cp file_contexts /etc/selinux/dummy/contexts/files
+cp dbus_contexts /etc/selinux/dummy/contexts
+cp policy.$VERS /etc/selinux/dummy/policy
+FC_FILE=/etc/selinux/dummy/contexts/files/file_contexts
+
+if [ ! -d /etc/selinux ]; then
+	mkdir -p /etc/selinux
+fi
+if [ -f /etc/selinux/config ]; then
+    echo "/etc/selinux/config exists, moving to /etc/selinux/config.bak."
+    mv /etc/selinux/config /etc/selinux/config.bak
+fi
+echo "Creating new /etc/selinux/config for dummy policy."
+cat > /etc/selinux/config << EOF
+SELINUX=permissive
+SELINUXTYPE=dummy
+EOF
+
+cd /etc/selinux/dummy/contexts/files
+$SF -F file_contexts /
+
+mounts=`cat /proc/$$/mounts | \
+	grep -E "ext[234]|jfs|xfs|jffs2|gfs2|btrfs|f2fs|ocfs2" | \
+	awk '{ print $2 '}`
+$SF -F file_contexts $mounts
+
+echo "-F" > /.autorelabel
-- 
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