arm64/boot: Disable trapping of PMZR_EL0 writes to EL2grafted

__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>

1 files changed, 27 insertions, 0 deletions

diff --git a/scripts/mkcompile_h b/scripts/mkcompile_h
new file mode 100755
index 000000000..2596f78e5
--- /dev/null
+++ b/scripts/mkcompile_h
@@ -0,0 +1,27 @@
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+UTS_MACHINE=$1
+CC_VERSION="$2"
+LD=$3
+
+if test -z "$KBUILD_BUILD_USER"; then
+	LINUX_COMPILE_BY=$(whoami | sed 's/\\/\\\\/')
+else
+	LINUX_COMPILE_BY=$KBUILD_BUILD_USER
+fi
+if test -z "$KBUILD_BUILD_HOST"; then
+	LINUX_COMPILE_HOST=`uname -n`
+else
+	LINUX_COMPILE_HOST=$KBUILD_BUILD_HOST
+fi
+
+LD_VERSION=$(LC_ALL=C $LD -v | head -n1 |
+		sed -e 's/(compatible with [^)]*)//' -e 's/[[:space:]]*$//')
+
+cat <<EOF
+#define UTS_MACHINE		"${UTS_MACHINE}"
+#define LINUX_COMPILE_BY	"${LINUX_COMPILE_BY}"
+#define LINUX_COMPILE_HOST	"${LINUX_COMPILE_HOST}"
+#define LINUX_COMPILER		"${CC_VERSION}, ${LD_VERSION}"
+EOF