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| author | Fuad Tabba <fuad.tabba@linux.dev> | 2026-09-22 19:14:30 +0100 |
|---|---|---|
| committer | Will Deacon <will@kernel.org> | 2026-09-23 12:34:30 +0000 |
| commit | 2bc6b218717b9d08f466f88209251d54bc09b207 (patch) | |
| tree | cb91c941eccb15f94cbec4e96aa3a9c8736b5d66 /scripts/Makefile.kstack_erase | |
| download | linux-stable-2bc6b218717b9d08f466f88209251d54bc09b207.tar.gz linux-stable-2bc6b218717b9d08f466f88209251d54bc09b207.zip | |
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>
Diffstat (limited to 'scripts/Makefile.kstack_erase')
| -rw-r--r-- | scripts/Makefile.kstack_erase | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/scripts/Makefile.kstack_erase b/scripts/Makefile.kstack_erase new file mode 100644 index 000000000..ee7e4ef7b --- /dev/null +++ b/scripts/Makefile.kstack_erase @@ -0,0 +1,21 @@ +# SPDX-License-Identifier: GPL-2.0 + +ifdef CONFIG_GCC_PLUGIN_STACKLEAK +kstack-erase-cflags-y += -fplugin=$(objtree)/scripts/gcc-plugins/stackleak_plugin.so +kstack-erase-cflags-y += -fplugin-arg-stackleak_plugin-track-min-size=$(CONFIG_KSTACK_ERASE_TRACK_MIN_SIZE) +kstack-erase-cflags-y += -fplugin-arg-stackleak_plugin-arch=$(SRCARCH) +kstack-erase-cflags-$(CONFIG_GCC_PLUGIN_STACKLEAK_VERBOSE) += -fplugin-arg-stackleak_plugin-verbose +DISABLE_KSTACK_ERASE := -fplugin-arg-stackleak_plugin-disable +endif + +ifdef CONFIG_CC_IS_CLANG +kstack-erase-cflags-y += -fsanitize-coverage=stack-depth +kstack-erase-cflags-y += -fsanitize-coverage-stack-depth-callback-min=$(CONFIG_KSTACK_ERASE_TRACK_MIN_SIZE) +DISABLE_KSTACK_ERASE := -fno-sanitize-coverage=stack-depth +endif + +KSTACK_ERASE_CFLAGS := $(kstack-erase-cflags-y) + +export KSTACK_ERASE_CFLAGS DISABLE_KSTACK_ERASE + +KBUILD_CFLAGS += $(KSTACK_ERASE_CFLAGS) |