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![Ard Biesheuvel](/assets/img/avatar_default.png)
This module tests the module loader's ELF relocation processing routines. When loaded, it logs output like below. Relocation test: ------------------------------------------------------- R_AARCH64_ABS64 0xffff880000cccccc pass R_AARCH64_ABS32 0x00000000f800cccc pass R_AARCH64_ABS16 0x000000000000f8cc pass R_AARCH64_MOVW_SABS_Gn 0xffff880000cccccc pass R_AARCH64_MOVW_UABS_Gn 0xffff880000cccccc pass R_AARCH64_ADR_PREL_LO21 0xffffff9cf4d1a400 pass R_AARCH64_PREL64 0xffffff9cf4d1a400 pass R_AARCH64_PREL32 0xffffff9cf4d1a400 pass R_AARCH64_PREL16 0xffffff9cf4d1a400 pass Acked-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
101 lines
3.4 KiB
Text
101 lines
3.4 KiB
Text
menu "Kernel hacking"
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source "lib/Kconfig.debug"
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config ARM64_PTDUMP_CORE
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def_bool n
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config ARM64_PTDUMP_DEBUGFS
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bool "Export kernel pagetable layout to userspace via debugfs"
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depends on DEBUG_KERNEL
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select ARM64_PTDUMP_CORE
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select DEBUG_FS
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help
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Say Y here if you want to show the kernel pagetable layout in a
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debugfs file. This information is only useful for kernel developers
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who are working in architecture specific areas of the kernel.
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It is probably not a good idea to enable this feature in a production
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kernel.
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If in doubt, say N.
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config PID_IN_CONTEXTIDR
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bool "Write the current PID to the CONTEXTIDR register"
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help
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Enabling this option causes the kernel to write the current PID to
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the CONTEXTIDR register, at the expense of some additional
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instructions during context switch. Say Y here only if you are
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planning to use hardware trace tools with this kernel.
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config ARM64_RANDOMIZE_TEXT_OFFSET
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bool "Randomize TEXT_OFFSET at build time"
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help
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Say Y here if you want the image load offset (AKA TEXT_OFFSET)
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of the kernel to be randomized at build-time. When selected,
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this option will cause TEXT_OFFSET to be randomized upon any
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build of the kernel, and the offset will be reflected in the
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text_offset field of the resulting Image. This can be used to
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fuzz-test bootloaders which respect text_offset.
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This option is intended for bootloader and/or kernel testing
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only. Bootloaders must make no assumptions regarding the value
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of TEXT_OFFSET and platforms must not require a specific
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value.
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config DEBUG_WX
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bool "Warn on W+X mappings at boot"
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select ARM64_PTDUMP_CORE
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---help---
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Generate a warning if any W+X mappings are found at boot.
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This is useful for discovering cases where the kernel is leaving
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W+X mappings after applying NX, as such mappings are a security risk.
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This check also includes UXN, which should be set on all kernel
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mappings.
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Look for a message in dmesg output like this:
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arm64/mm: Checked W+X mappings: passed, no W+X pages found.
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or like this, if the check failed:
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arm64/mm: Checked W+X mappings: FAILED, <N> W+X pages found.
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Note that even if the check fails, your kernel is possibly
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still fine, as W+X mappings are not a security hole in
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themselves, what they do is that they make the exploitation
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of other unfixed kernel bugs easier.
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There is no runtime or memory usage effect of this option
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once the kernel has booted up - it's a one time check.
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If in doubt, say "Y".
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config DEBUG_ALIGN_RODATA
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depends on STRICT_KERNEL_RWX
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bool "Align linker sections up to SECTION_SIZE"
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help
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If this option is enabled, sections that may potentially be marked as
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read only or non-executable will be aligned up to the section size of
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the kernel. This prevents sections from being split into pages and
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avoids a potential TLB penalty. The downside is an increase in
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alignment and potentially wasted space. Turn on this option if
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performance is more important than memory pressure.
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If in doubt, say N.
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config DEBUG_EFI
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depends on EFI && DEBUG_INFO
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bool "UEFI debugging"
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help
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Enable this option to include EFI specific debugging features into
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the kernel that are only useful when using a debug build of the
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UEFI firmware
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config ARM64_RELOC_TEST
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depends on m
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tristate "Relocation testing module"
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source "drivers/hwtracing/coresight/Kconfig"
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endmenu
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