arch/arm64/Kconfig.debug

   1 menu "Kernel hacking"
   2
   3 source "lib/Kconfig.debug"
   4
   5 config ARM64_PTDUMP_CORE
   6         def_bool n
   7
   8 config ARM64_PTDUMP_DEBUGFS
   9         bool "Export kernel pagetable layout to userspace via debugfs"
  10         depends on DEBUG_KERNEL
  11         select ARM64_PTDUMP_CORE
  12         select DEBUG_FS
  13         help
  14           Say Y here if you want to show the kernel pagetable layout in a
  15           debugfs file. This information is only useful for kernel developers
  16           who are working in architecture specific areas of the kernel.
  17           It is probably not a good idea to enable this feature in a production
  18           kernel.
  19
  20           If in doubt, say N.
  21
  22 config PID_IN_CONTEXTIDR
  23         bool "Write the current PID to the CONTEXTIDR register"
  24         help
  25           Enabling this option causes the kernel to write the current PID to
  26           the CONTEXTIDR register, at the expense of some additional
  27           instructions during context switch. Say Y here only if you are
  28           planning to use hardware trace tools with this kernel.
  29
  30 config ARM64_RANDOMIZE_TEXT_OFFSET
  31         bool "Randomize TEXT_OFFSET at build time"
  32         help
  33           Say Y here if you want the image load offset (AKA TEXT_OFFSET)
  34           of the kernel to be randomized at build-time. When selected,
  35           this option will cause TEXT_OFFSET to be randomized upon any
  36           build of the kernel, and the offset will be reflected in the
  37           text_offset field of the resulting Image. This can be used to
  38           fuzz-test bootloaders which respect text_offset.
  39
  40           This option is intended for bootloader and/or kernel testing
  41           only. Bootloaders must make no assumptions regarding the value
  42           of TEXT_OFFSET and platforms must not require a specific
  43           value.
  44
  45 config DEBUG_WX
  46         bool "Warn on W+X mappings at boot"
  47         select ARM64_PTDUMP_CORE
  48         ---help---
  49           Generate a warning if any W+X mappings are found at boot.
  50
  51           This is useful for discovering cases where the kernel is leaving
  52           W+X mappings after applying NX, as such mappings are a security risk.
  53           This check also includes UXN, which should be set on all kernel
  54           mappings.
  55
  56           Look for a message in dmesg output like this:
  57
  58             arm64/mm: Checked W+X mappings: passed, no W+X pages found.
  59
  60           or like this, if the check failed:
  61
  62             arm64/mm: Checked W+X mappings: FAILED, <N> W+X pages found.
  63
  64           Note that even if the check fails, your kernel is possibly
  65           still fine, as W+X mappings are not a security hole in
  66           themselves, what they do is that they make the exploitation
  67           of other unfixed kernel bugs easier.
  68
  69           There is no runtime or memory usage effect of this option
  70           once the kernel has booted up - it's a one time check.
  71
  72           If in doubt, say "Y".
  73
  74 config DEBUG_ALIGN_RODATA
  75         depends on STRICT_KERNEL_RWX
  76         bool "Align linker sections up to SECTION_SIZE"
  77         help
  78           If this option is enabled, sections that may potentially be marked as
  79           read only or non-executable will be aligned up to the section size of
  80           the kernel. This prevents sections from being split into pages and
  81           avoids a potential TLB penalty. The downside is an increase in
  82           alignment and potentially wasted space. Turn on this option if
  83           performance is more important than memory pressure.
  84
  85           If in doubt, say N.
  86
  87 config DEBUG_EFI
  88         depends on EFI && DEBUG_INFO
  89         bool "UEFI debugging"
  90         help
  91           Enable this option to include EFI specific debugging features into
  92           the kernel that are only useful when using a debug build of the
  93           UEFI firmware
  94
  95 config ARM64_RELOC_TEST
  96         depends on m
  97         tristate "Relocation testing module"
  98
  99 source "drivers/hwtracing/coresight/Kconfig"
 100
 101 endmenu