arch/arm64/Kconfig.debug

   1 menu "Kernel hacking"
   2
   3 source "lib/Kconfig.debug"
   4
   5 config FRAME_POINTER
   6         bool
   7         default y
   8
   9 config ARM64_PTDUMP
  10         bool "Export kernel pagetable layout to userspace via debugfs"
  11         depends on DEBUG_KERNEL
  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           If in doubt, say "N"
  20
  21 config STRICT_DEVMEM
  22         bool "Filter access to /dev/mem"
  23         depends on MMU
  24         help
  25           If this option is disabled, you allow userspace (root) access to all
  26           of memory, including kernel and userspace memory. Accidental
  27           access to this is obviously disastrous, but specific access can
  28           be used by people debugging the kernel.
  29
  30           If this option is switched on, the /dev/mem file only allows
  31           userspace access to memory mapped peripherals.
  32
  33           If in doubt, say Y.
  34
  35 config PID_IN_CONTEXTIDR
  36         bool "Write the current PID to the CONTEXTIDR register"
  37         help
  38           Enabling this option causes the kernel to write the current PID to
  39           the CONTEXTIDR register, at the expense of some additional
  40           instructions during context switch. Say Y here only if you are
  41           planning to use hardware trace tools with this kernel.
  42
  43 config ARM64_RANDOMIZE_TEXT_OFFSET
  44         bool "Randomize TEXT_OFFSET at build time"
  45         help
  46           Say Y here if you want the image load offset (AKA TEXT_OFFSET)
  47           of the kernel to be randomized at build-time. When selected,
  48           this option will cause TEXT_OFFSET to be randomized upon any
  49           build of the kernel, and the offset will be reflected in the
  50           text_offset field of the resulting Image. This can be used to
  51           fuzz-test bootloaders which respect text_offset.
  52
  53           This option is intended for bootloader and/or kernel testing
  54           only. Bootloaders must make no assumptions regarding the value
  55           of TEXT_OFFSET and platforms must not require a specific
  56           value.
  57
  58 config DEBUG_SET_MODULE_RONX
  59         bool "Set loadable kernel module data as NX and text as RO"
  60         depends on MODULES
  61         help
  62           This option helps catch unintended modifications to loadable
  63           kernel module's text and read-only data. It also prevents execution
  64           of module data. Such protection may interfere with run-time code
  65           patching and dynamic kernel tracing - and they might also protect
  66           against certain classes of kernel exploits.
  67           If in doubt, say "N".
  68
  69 config DEBUG_RODATA
  70         bool "Make kernel text and rodata read-only"
  71         help
  72           If this is set, kernel text and rodata will be made read-only. This
  73           is to help catch accidental or malicious attempts to change the
  74           kernel's executable code. Additionally splits rodata from kernel
  75           text so it can be made explicitly non-executable.
  76
  77           If in doubt, say Y
  78
  79 config DEBUG_ALIGN_RODATA
  80         depends on DEBUG_RODATA && ARM64_4K_PAGES
  81         bool "Align linker sections up to SECTION_SIZE"
  82         help
  83           If this option is enabled, sections that may potentially be marked as
  84           read only or non-executable will be aligned up to the section size of
  85           the kernel. This prevents sections from being split into pages and
  86           avoids a potential TLB penalty. The downside is an increase in
  87           alignment and potentially wasted space. Turn on this option if
  88           performance is more important than memory pressure.
  89
  90           If in doubt, say N
  91
  92 source "drivers/hwtracing/coresight/Kconfig"
  93
  94 endmenu