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, 45 insertions, 0 deletions

diff --git a/drivers/hid/hid-macally.c b/drivers/hid/hid-macally.c
new file mode 100644
index 000000000..fe7576458
--- /dev/null
+++ b/drivers/hid/hid-macally.c
@@ -0,0 +1,45 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ *  HID driver for quirky Macally devices
+ *
+ *  Copyright (c) 2019 Alex Henrie <alexhenrie24@gmail.com>
+ */
+
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+MODULE_AUTHOR("Alex Henrie <alexhenrie24@gmail.com>");
+MODULE_DESCRIPTION("Macally devices");
+MODULE_LICENSE("GPL");
+
+/*
+ * The Macally ikey keyboard says that its logical and usage maximums are both
+ * 101, but the power key is 102 and the equals key is 103
+ */
+static const __u8 *macally_report_fixup(struct hid_device *hdev, __u8 *rdesc,
+					unsigned int *rsize)
+{
+	if (*rsize >= 60 && rdesc[53] == 0x65 && rdesc[59] == 0x65) {
+		hid_info(hdev,
+			"fixing up Macally ikey keyboard report descriptor\n");
+		rdesc[53] = rdesc[59] = 0x67;
+	}
+	return rdesc;
+}
+
+static const struct hid_device_id macally_id_table[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_SOLID_YEAR,
+			 USB_DEVICE_ID_MACALLY_IKEY_KEYBOARD) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, macally_id_table);
+
+static struct hid_driver macally_driver = {
+	.name			= "macally",
+	.id_table		= macally_id_table,
+	.report_fixup		= macally_report_fixup,
+};
+
+module_hid_driver(macally_driver);