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, 51 insertions, 0 deletions

diff --git a/include/trace/events/fsnotify.h b/include/trace/events/fsnotify.h
new file mode 100644
index 000000000..341bbd57a
--- /dev/null
+++ b/include/trace/events/fsnotify.h
@@ -0,0 +1,51 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#undef TRACE_SYSTEM
+#define TRACE_SYSTEM fsnotify
+
+#if !defined(_TRACE_FSNOTIFY_H) || defined(TRACE_HEADER_MULTI_READ)
+#define _TRACE_FSNOTIFY_H
+
+#include <linux/tracepoint.h>
+
+#include <trace/misc/fsnotify.h>
+
+TRACE_EVENT(fsnotify,
+	TP_PROTO(__u32 mask, const void *data, int data_type,
+		 struct inode *dir, const struct qstr *file_name,
+		 struct inode *inode, u32 cookie),
+
+	TP_ARGS(mask, data, data_type, dir, file_name, inode, cookie),
+
+	TP_STRUCT__entry(
+		__field(__u32, mask)
+		__field(unsigned long, dir_ino)
+		__field(unsigned long, ino)
+		__field(dev_t, s_dev)
+		__field(int, data_type)
+		__field(u32, cookie)
+		__string(file_name, file_name ? (const char *)file_name->name : "")
+	),
+
+	TP_fast_assign(
+		__entry->mask = mask;
+		__entry->dir_ino = dir ? dir->i_ino : 0;
+		__entry->ino = inode ? inode->i_ino : 0;
+		__entry->s_dev = dir ? dir->i_sb->s_dev :
+				 inode ? inode->i_sb->s_dev : 0;
+		__entry->data_type = data_type;
+		__entry->cookie = cookie;
+		__assign_str(file_name);
+	),
+
+	TP_printk("dev=%d:%d dir=%lu ino=%lu data_type=%d cookie=0x%x mask=0x%x %s name=%s",
+		  MAJOR(__entry->s_dev), MINOR(__entry->s_dev),
+		  __entry->dir_ino, __entry->ino,
+		  __entry->data_type, __entry->cookie,
+		  __entry->mask, show_fsnotify_mask(__entry->mask),
+		  __get_str(file_name))
+);
+
+#endif /* _TRACE_FSNOTIFY_H */
+
+/* This part must be outside protection */
+#include <trace/define_trace.h>