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