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, 52 insertions, 0 deletions

diff --git a/scripts/Makefile.debug b/scripts/Makefile.debug
new file mode 100644
index 000000000..107db997c
--- /dev/null
+++ b/scripts/Makefile.debug
@@ -0,0 +1,52 @@
+DEBUG_CFLAGS	:=
+DEBUG_RUSTFLAGS	:=
+
+debug-flags-y	:= -g
+
+ifdef CONFIG_DEBUG_INFO_SPLIT
+DEBUG_CFLAGS	+= -gsplit-dwarf
+endif
+
+debug-flags-$(CONFIG_DEBUG_INFO_DWARF4)	+= -gdwarf-4
+debug-flags-$(CONFIG_DEBUG_INFO_DWARF5)	+= -gdwarf-5
+ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_AS_IS_GNU),yy)
+# Clang does not pass -g or -gdwarf-* option down to GAS.
+# Add -Wa, prefix to explicitly specify the flags.
+KBUILD_AFLAGS	+= $(addprefix -Wa$(comma), $(debug-flags-y))
+endif
+DEBUG_CFLAGS	+= $(debug-flags-y)
+KBUILD_AFLAGS	+= $(debug-flags-y)
+
+ifdef CONFIG_DEBUG_INFO_DWARF4
+DEBUG_RUSTFLAGS	+= -Zdwarf-version=4
+else ifdef CONFIG_DEBUG_INFO_DWARF5
+DEBUG_RUSTFLAGS	+= -Zdwarf-version=5
+endif
+
+ifdef CONFIG_DEBUG_INFO_REDUCED
+DEBUG_CFLAGS	+= -fno-var-tracking
+DEBUG_RUSTFLAGS	+= -Cdebuginfo=1
+ifdef CONFIG_CC_IS_GCC
+DEBUG_CFLAGS	+= -femit-struct-debug-baseonly
+endif
+else
+DEBUG_RUSTFLAGS	+= -Cdebuginfo=2
+endif
+
+ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZLIB
+DEBUG_CFLAGS	+= -gz=zlib
+DEBUG_RUSTFLAGS	+= -Zdebuginfo-compression=zlib
+KBUILD_AFLAGS	+= -gz=zlib
+KBUILD_LDFLAGS	+= --compress-debug-sections=zlib
+else ifdef CONFIG_DEBUG_INFO_COMPRESSED_ZSTD
+DEBUG_CFLAGS	+= -gz=zstd
+DEBUG_RUSTFLAGS	+= -Zdebuginfo-compression=zstd
+KBUILD_AFLAGS	+= -gz=zstd
+KBUILD_LDFLAGS	+= --compress-debug-sections=zstd
+endif
+
+KBUILD_CFLAGS	+= $(DEBUG_CFLAGS)
+export DEBUG_CFLAGS
+
+KBUILD_RUSTFLAGS += $(DEBUG_RUSTFLAGS)
+export DEBUG_RUSTFLAGS