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, 62 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/resource.h b/include/uapi/asm-generic/resource.h
new file mode 100644
index 000000000..f12db7a0d
--- /dev/null
+++ b/include/uapi/asm-generic/resource.h
@@ -0,0 +1,62 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_ASM_GENERIC_RESOURCE_H
+#define _UAPI_ASM_GENERIC_RESOURCE_H
+
+/*
+ * Resource limit IDs
+ *
+ * ( Compatibility detail: there are architectures that have
+ *   a different rlimit ID order in the 5-9 range and want
+ *   to keep that order for binary compatibility. The reasons
+ *   are historic and all new rlimits are identical across all
+ *   arches. If an arch has such special order for some rlimits
+ *   then it defines them prior including asm-generic/resource.h. )
+ */
+
+#define RLIMIT_CPU		0	/* CPU time in sec */
+#define RLIMIT_FSIZE		1	/* Maximum filesize */
+#define RLIMIT_DATA		2	/* max data size */
+#define RLIMIT_STACK		3	/* max stack size */
+#define RLIMIT_CORE		4	/* max core file size */
+
+#ifndef RLIMIT_RSS
+# define RLIMIT_RSS		5	/* max resident set size */
+#endif
+
+#ifndef RLIMIT_NPROC
+# define RLIMIT_NPROC		6	/* max number of processes */
+#endif
+
+#ifndef RLIMIT_NOFILE
+# define RLIMIT_NOFILE		7	/* max number of open files */
+#endif
+
+#ifndef RLIMIT_MEMLOCK
+# define RLIMIT_MEMLOCK		8	/* max locked-in-memory address space */
+#endif
+
+#ifndef RLIMIT_AS
+# define RLIMIT_AS		9	/* address space limit */
+#endif
+
+#define RLIMIT_LOCKS		10	/* maximum file locks held */
+#define RLIMIT_SIGPENDING	11	/* max number of pending signals */
+#define RLIMIT_MSGQUEUE		12	/* maximum bytes in POSIX mqueues */
+#define RLIMIT_NICE		13	/* max nice prio allowed to raise to
+					   0-39 for nice level 19 .. -20 */
+#define RLIMIT_RTPRIO		14	/* maximum realtime priority */
+#define RLIMIT_RTTIME		15	/* timeout for RT tasks in us */
+#define RLIM_NLIMITS		16
+
+/*
+ * SuS says limits have to be unsigned.
+ * Which makes a ton more sense anyway.
+ *
+ * Some architectures override this (for compatibility reasons):
+ */
+#ifndef RLIM_INFINITY
+# define RLIM_INFINITY		(~0UL)
+#endif
+
+
+#endif /* _UAPI_ASM_GENERIC_RESOURCE_H */