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, 30 insertions, 0 deletions

diff --git a/scripts/extract-fwblobs b/scripts/extract-fwblobs
new file mode 100755
index 000000000..53729124e
--- /dev/null
+++ b/scripts/extract-fwblobs
@@ -0,0 +1,30 @@
+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# -----------------------------------------------------------------------------
+# Extracts the vmlinux built-in firmware blobs - requires a non-stripped image
+# -----------------------------------------------------------------------------
+
+if [ -z "$1" ]; then
+	echo "Must provide a non-stripped vmlinux as argument"
+	exit 1
+fi
+
+read -r RD_ADDR_HEX RD_OFF_HEX <<< "$( readelf -SW "$1" |\
+grep -w rodata | awk '{print "0x"$5" 0x"$6}' )"
+
+FW_SYMS="$(readelf -sW "$1" |\
+awk -n '/fw_end/ { end=$2 ; print name " 0x" start " 0x" end; } { start=$2; name=$8; }')"
+
+while IFS= read -r entry; do
+	read -r FW_NAME FW_ADDR_ST_HEX FW_ADDR_END_HEX <<< "$entry"
+
+	# Notice kernel prepends _fw_ and appends _bin to the FW name
+	# in rodata; hence we hereby filter that out.
+	FW_NAME=${FW_NAME:4:-4}
+
+	FW_OFFSET="$(printf "%d" $((FW_ADDR_ST_HEX - RD_ADDR_HEX + RD_OFF_HEX)))"
+	FW_SIZE="$(printf "%d" $((FW_ADDR_END_HEX - FW_ADDR_ST_HEX)))"
+
+	dd if="$1" of="./${FW_NAME}" bs="${FW_SIZE}" count=1 iflag=skip_bytes skip="${FW_OFFSET}"
+done <<< "${FW_SYMS}"