84b04d3e6b
The asm code that creates the initial ID map is rather intricate and hard to follow. This is problematic because it makes adding support for things like LPA2 or WXN more difficult than necessary. Also, it is parameterized like the rest of the MM code to run with a configurable number of levels, which is rather pointless, given that all AArch64 CPUs implement support for 48-bit virtual addressing, and that many systems exist with DRAM located outside of the 39-bit addressable range, which is the only smaller VA size that is widely used, and we need additional tricks to make things work in that combination. So let's bite the bullet, and rip out all the asm macros, and fiddly code, and replace it with a C implementation based on the newly added routines for creating the early kernel VA mappings. And while at it, create the initial ID map based on 48-bit virtual addressing as well, regardless of the number of configured levels for the kernel proper. Note that this code may execute with the MMU and caches disabled, and is therefore not permitted to make unaligned accesses. This shouldn't generally happen in any case for the algorithm as implemented, but to be sure, let's pass -mstrict-align to the compiler just in case. Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Link: https://lore.kernel.org/r/20240214122845.2033971-66-ardb+git@google.com Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
51 lines
1.7 KiB
Makefile
51 lines
1.7 KiB
Makefile
# SPDX-License-Identifier: GPL-2.0
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# Copyright 2022 Google LLC
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KBUILD_CFLAGS := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) -fpie \
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-Os -DDISABLE_BRANCH_PROFILING $(DISABLE_STACKLEAK_PLUGIN) \
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$(DISABLE_LATENT_ENTROPY_PLUGIN) \
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$(call cc-option,-mbranch-protection=none) \
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-I$(srctree)/scripts/dtc/libfdt -fno-stack-protector \
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-include $(srctree)/include/linux/hidden.h \
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-D__DISABLE_EXPORTS -ffreestanding -D__NO_FORTIFY \
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-fno-asynchronous-unwind-tables -fno-unwind-tables \
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$(call cc-option,-fno-addrsig)
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# this code may run with the MMU off so disable unaligned accesses
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CFLAGS_map_range.o += -mstrict-align
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# remove SCS flags from all objects in this directory
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KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_SCS), $(KBUILD_CFLAGS))
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# disable LTO
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KBUILD_CFLAGS := $(filter-out $(CC_FLAGS_LTO), $(KBUILD_CFLAGS))
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GCOV_PROFILE := n
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KASAN_SANITIZE := n
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KCSAN_SANITIZE := n
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UBSAN_SANITIZE := n
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KCOV_INSTRUMENT := n
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hostprogs := relacheck
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quiet_cmd_piobjcopy = $(quiet_cmd_objcopy)
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cmd_piobjcopy = $(cmd_objcopy) && $(obj)/relacheck $(@) $(<)
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$(obj)/%.pi.o: OBJCOPYFLAGS := --prefix-symbols=__pi_ \
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--remove-section=.note.gnu.property
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$(obj)/%.pi.o: $(obj)/%.o $(obj)/relacheck FORCE
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$(call if_changed,piobjcopy)
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# ensure that all the lib- code ends up as __init code and data
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$(obj)/lib-%.pi.o: OBJCOPYFLAGS += --prefix-alloc-sections=.init
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$(obj)/lib-%.o: $(srctree)/lib/%.c FORCE
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$(call if_changed_rule,cc_o_c)
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obj-y := idreg-override.pi.o \
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map_kernel.pi.o map_range.pi.o \
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lib-fdt.pi.o lib-fdt_ro.pi.o
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obj-$(CONFIG_RELOCATABLE) += relocate.pi.o
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obj-$(CONFIG_RANDOMIZE_BASE) += kaslr_early.pi.o
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obj-$(CONFIG_UNWIND_PATCH_PAC_INTO_SCS) += patch-scs.pi.o
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extra-y := $(patsubst %.pi.o,%.o,$(obj-y))
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