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, 53 insertions, 0 deletions

diff --git a/scripts/include/xalloc.h b/scripts/include/xalloc.h
new file mode 100644
index 000000000..cdadb07d0
--- /dev/null
+++ b/scripts/include/xalloc.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef XALLOC_H
+#define XALLOC_H
+
+#include <stdlib.h>
+#include <string.h>
+
+static inline void *xmalloc(size_t size)
+{
+	void *p = malloc(size);
+
+	if (!p)
+		exit(1);
+	return p;
+}
+
+static inline void *xcalloc(size_t nmemb, size_t size)
+{
+	void *p = calloc(nmemb, size);
+
+	if (!p)
+		exit(1);
+	return p;
+}
+
+static inline void *xrealloc(void *p, size_t size)
+{
+	p = realloc(p, size);
+	if (!p)
+		exit(1);
+	return p;
+}
+
+static inline char *xstrdup(const char *s)
+{
+	char *p = strdup(s);
+
+	if (!p)
+		exit(1);
+	return p;
+}
+
+static inline char *xstrndup(const char *s, size_t n)
+{
+	char *p = strndup(s, n);
+
+	if (!p)
+		exit(1);
+	return p;
+}
+
+#endif /* XALLOC_H */