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, 73 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/stat.h b/include/uapi/asm-generic/stat.h
new file mode 100644
index 000000000..0d962ecd1
--- /dev/null
+++ b/include/uapi/asm-generic/stat.h
@@ -0,0 +1,73 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef __ASM_GENERIC_STAT_H
+#define __ASM_GENERIC_STAT_H
+
+/*
+ * Everybody gets this wrong and has to stick with it for all
+ * eternity. Hopefully, this version gets used by new architectures
+ * so they don't fall into the same traps.
+ *
+ * stat64 is copied from powerpc64, with explicit padding added.
+ * stat is the same structure layout on 64-bit, without the 'long long'
+ * types.
+ *
+ * By convention, 64 bit architectures use the stat interface, while
+ * 32 bit architectures use the stat64 interface. Note that we don't
+ * provide an __old_kernel_stat here, which new architecture should
+ * not have to start with.
+ */
+
+#include <asm/bitsperlong.h>
+
+#define STAT_HAVE_NSEC 1
+
+struct stat {
+	unsigned long	st_dev;		/* Device.  */
+	unsigned long	st_ino;		/* File serial number.  */
+	unsigned int	st_mode;	/* File mode.  */
+	unsigned int	st_nlink;	/* Link count.  */
+	unsigned int	st_uid;		/* User ID of the file's owner.  */
+	unsigned int	st_gid;		/* Group ID of the file's group. */
+	unsigned long	st_rdev;	/* Device number, if device.  */
+	unsigned long	__pad1;
+	long		st_size;	/* Size of file, in bytes.  */
+	int		st_blksize;	/* Optimal block size for I/O.  */
+	int		__pad2;
+	long		st_blocks;	/* Number 512-byte blocks allocated. */
+	long		st_atime;	/* Time of last access.  */
+	unsigned long	st_atime_nsec;
+	long		st_mtime;	/* Time of last modification.  */
+	unsigned long	st_mtime_nsec;
+	long		st_ctime;	/* Time of last status change.  */
+	unsigned long	st_ctime_nsec;
+	unsigned int	__unused4;
+	unsigned int	__unused5;
+};
+
+/* This matches struct stat64 in glibc2.1. Only used for 32 bit. */
+#if __BITS_PER_LONG != 64 || defined(__ARCH_WANT_STAT64)
+struct stat64 {
+	unsigned long long st_dev;	/* Device.  */
+	unsigned long long st_ino;	/* File serial number.  */
+	unsigned int	st_mode;	/* File mode.  */
+	unsigned int	st_nlink;	/* Link count.  */
+	unsigned int	st_uid;		/* User ID of the file's owner.  */
+	unsigned int	st_gid;		/* Group ID of the file's group. */
+	unsigned long long st_rdev;	/* Device number, if device.  */
+	unsigned long long __pad1;
+	long long	st_size;	/* Size of file, in bytes.  */
+	int		st_blksize;	/* Optimal block size for I/O.  */
+	int		__pad2;
+	long long	st_blocks;	/* Number 512-byte blocks allocated. */
+	int		st_atime;	/* Time of last access.  */
+	unsigned int	st_atime_nsec;
+	int		st_mtime;	/* Time of last modification.  */
+	unsigned int	st_mtime_nsec;
+	int		st_ctime;	/* Time of last status change.  */
+	unsigned int	st_ctime_nsec;
+	unsigned int	__unused4;
+	unsigned int	__unused5;
+};
+#endif
+
+#endif /* __ASM_GENERIC_STAT_H */