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, 124 insertions, 0 deletions

diff --git a/drivers/dma-buf/sync_debug.c b/drivers/dma-buf/sync_debug.c
new file mode 100644
index 000000000..9e5d662cd
--- /dev/null
+++ b/drivers/dma-buf/sync_debug.c
@@ -0,0 +1,124 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Sync File validation framework and debug information
+ *
+ * Copyright (C) 2012 Google, Inc.
+ */
+
+#include <linux/debugfs.h>
+#include "sync_debug.h"
+
+static struct dentry *dbgfs;
+
+static LIST_HEAD(sync_timeline_list_head);
+static DEFINE_SPINLOCK(sync_timeline_list_lock);
+
+void sync_timeline_debug_add(struct sync_timeline *obj)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sync_timeline_list_lock, flags);
+	list_add_tail(&obj->sync_timeline_list, &sync_timeline_list_head);
+	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+}
+
+void sync_timeline_debug_remove(struct sync_timeline *obj)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&sync_timeline_list_lock, flags);
+	list_del(&obj->sync_timeline_list);
+	spin_unlock_irqrestore(&sync_timeline_list_lock, flags);
+}
+
+static const char *sync_status_str(int status)
+{
+	if (status < 0)
+		return "error";
+
+	if (status > 0)
+		return "signaled";
+
+	return "active";
+}
+
+static void sync_print_fence(struct seq_file *s,
+			     struct dma_fence *fence, bool show)
+{
+	struct sync_timeline *parent = dma_fence_parent(fence);
+	int status;
+
+	status = dma_fence_get_status_locked(fence);
+
+	seq_printf(s, "  %s%sfence %s",
+		   show ? parent->name : "",
+		   show ? "_" : "",
+		   sync_status_str(status));
+
+	if (test_bit(DMA_FENCE_FLAG_TIMESTAMP_BIT, &fence->flags)) {
+		struct timespec64 ts64 =
+			ktime_to_timespec64(fence->timestamp);
+
+		seq_printf(s, "@%ptSp", &ts64);
+	}
+
+	seq_printf(s, ": %lld", fence->seqno);
+	seq_printf(s, " / %d", parent->value);
+	seq_putc(s, '\n');
+}
+
+static void sync_print_obj(struct seq_file *s, struct sync_timeline *obj)
+{
+	struct list_head *pos;
+
+	seq_printf(s, "%s: %d\n", obj->name, obj->value);
+
+	spin_lock(&obj->lock); /* Caller already disabled IRQ. */
+	list_for_each(pos, &obj->pt_list) {
+		struct sync_pt *pt = container_of(pos, struct sync_pt, link);
+		sync_print_fence(s, &pt->base, false);
+	}
+	spin_unlock(&obj->lock);
+}
+
+static int sync_info_debugfs_show(struct seq_file *s, void *unused)
+{
+	struct list_head *pos;
+
+	seq_puts(s, "objs:\n--------------\n");
+
+	spin_lock_irq(&sync_timeline_list_lock);
+	list_for_each(pos, &sync_timeline_list_head) {
+		struct sync_timeline *obj =
+			container_of(pos, struct sync_timeline,
+				     sync_timeline_list);
+
+		sync_print_obj(s, obj);
+		seq_putc(s, '\n');
+	}
+	spin_unlock_irq(&sync_timeline_list_lock);
+
+	seq_puts(s, "fences:\n--------------\n");
+
+	return 0;
+}
+
+DEFINE_SHOW_ATTRIBUTE(sync_info_debugfs);
+
+static __init int sync_debugfs_init(void)
+{
+	dbgfs = debugfs_create_dir("sync", NULL);
+
+	/*
+	 * The debugfs files won't ever get removed and thus, there is
+	 * no need to protect it against removal races. The use of
+	 * debugfs_create_file_unsafe() is actually safe here.
+	 */
+	debugfs_create_file_unsafe("info", 0444, dbgfs, NULL,
+				   &sync_info_debugfs_fops);
+	debugfs_create_file_unsafe("sw_sync", 0644, dbgfs, NULL,
+				   &sw_sync_debugfs_fops);
+
+	return 0;
+}
+late_initcall(sync_debugfs_init);