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authorFuad Tabba <fuad.tabba@linux.dev>2026-09-22 19:14:30 +0100
committerWill Deacon <will@kernel.org>2026-09-23 12:34:30 +0000
commit2bc6b218717b9d08f466f88209251d54bc09b207 (patch)
treecb91c941eccb15f94cbec4e96aa3a9c8736b5d66 /scripts/Makefile.autofdo
downloadlinux-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.autofdo')
-rw-r--r--scripts/Makefile.autofdo28
1 files changed, 28 insertions, 0 deletions
diff --git a/scripts/Makefile.autofdo b/scripts/Makefile.autofdo
new file mode 100644
index 000000000..1442043da
--- /dev/null
+++ b/scripts/Makefile.autofdo
@@ -0,0 +1,28 @@
+# SPDX-License-Identifier: GPL-2.0
+
+# Enable available and selected Clang AutoFDO features.
+
+CFLAGS_AUTOFDO_CLANG := -fdebug-info-for-profiling -mllvm -enable-fs-discriminator=true -mllvm -improved-fs-discriminator=true
+RUSTFLAGS_AUTOFDO_CLANG := $(if $(call rustc-min-version,109800),-Zdebuginfo-for-profiling,-Zdebug-info-for-profiling) -Cllvm-args=-enable-fs-discriminator=true -Cllvm-args=-improved-fs-discriminator=true
+
+ifndef CONFIG_DEBUG_INFO
+ CFLAGS_AUTOFDO_CLANG += -gmlt
+ RUSTFLAGS_AUTOFDO_CLANG += -Cdebuginfo=line-tables-only
+endif
+
+ifdef CLANG_AUTOFDO_PROFILE
+ CFLAGS_AUTOFDO_CLANG += -fprofile-sample-use=$(CLANG_AUTOFDO_PROFILE) -ffunction-sections
+ CFLAGS_AUTOFDO_CLANG += -fsplit-machine-functions
+ RUSTFLAGS_AUTOFDO_CLANG += -Zprofile-sample-use=$(CLANG_AUTOFDO_PROFILE) -Zfunction-sections=y
+ RUSTFLAGS_AUTOFDO_CLANG += -Cllvm-args=-split-machine-functions
+endif
+
+ifdef CONFIG_LTO_CLANG_THIN
+ ifdef CLANG_AUTOFDO_PROFILE
+ KBUILD_LDFLAGS += --lto-sample-profile=$(CLANG_AUTOFDO_PROFILE)
+ endif
+ KBUILD_LDFLAGS += --mllvm=-enable-fs-discriminator=true --mllvm=-improved-fs-discriminator=true -plugin-opt=thinlto
+ KBUILD_LDFLAGS += -plugin-opt=-split-machine-functions
+endif
+
+export CFLAGS_AUTOFDO_CLANG RUSTFLAGS_AUTOFDO_CLANG