xref: /openbmc/linux/arch/arm64/Kconfig.debug (revision 5a170e9e)
1
2config ARM64_PTDUMP_CORE
3	def_bool n
4
5config ARM64_PTDUMP_DEBUGFS
6	bool "Export kernel pagetable layout to userspace via debugfs"
7	depends on DEBUG_KERNEL
8	select ARM64_PTDUMP_CORE
9	select DEBUG_FS
10        help
11	  Say Y here if you want to show the kernel pagetable layout in a
12	  debugfs file. This information is only useful for kernel developers
13	  who are working in architecture specific areas of the kernel.
14	  It is probably not a good idea to enable this feature in a production
15	  kernel.
16
17	  If in doubt, say N.
18
19config PID_IN_CONTEXTIDR
20	bool "Write the current PID to the CONTEXTIDR register"
21	help
22	  Enabling this option causes the kernel to write the current PID to
23	  the CONTEXTIDR register, at the expense of some additional
24	  instructions during context switch. Say Y here only if you are
25	  planning to use hardware trace tools with this kernel.
26
27config ARM64_RANDOMIZE_TEXT_OFFSET
28	bool "Randomize TEXT_OFFSET at build time"
29	help
30	  Say Y here if you want the image load offset (AKA TEXT_OFFSET)
31	  of the kernel to be randomized at build-time. When selected,
32	  this option will cause TEXT_OFFSET to be randomized upon any
33	  build of the kernel, and the offset will be reflected in the
34	  text_offset field of the resulting Image. This can be used to
35	  fuzz-test bootloaders which respect text_offset.
36
37	  This option is intended for bootloader and/or kernel testing
38	  only. Bootloaders must make no assumptions regarding the value
39	  of TEXT_OFFSET and platforms must not require a specific
40	  value.
41
42config DEBUG_WX
43	bool "Warn on W+X mappings at boot"
44	select ARM64_PTDUMP_CORE
45	---help---
46	  Generate a warning if any W+X mappings are found at boot.
47
48	  This is useful for discovering cases where the kernel is leaving
49	  W+X mappings after applying NX, as such mappings are a security risk.
50	  This check also includes UXN, which should be set on all kernel
51	  mappings.
52
53	  Look for a message in dmesg output like this:
54
55	    arm64/mm: Checked W+X mappings: passed, no W+X pages found.
56
57	  or like this, if the check failed:
58
59	    arm64/mm: Checked W+X mappings: FAILED, <N> W+X pages found.
60
61	  Note that even if the check fails, your kernel is possibly
62	  still fine, as W+X mappings are not a security hole in
63	  themselves, what they do is that they make the exploitation
64	  of other unfixed kernel bugs easier.
65
66	  There is no runtime or memory usage effect of this option
67	  once the kernel has booted up - it's a one time check.
68
69	  If in doubt, say "Y".
70
71config DEBUG_ALIGN_RODATA
72	depends on STRICT_KERNEL_RWX
73	bool "Align linker sections up to SECTION_SIZE"
74	help
75	  If this option is enabled, sections that may potentially be marked as
76	  read only or non-executable will be aligned up to the section size of
77	  the kernel. This prevents sections from being split into pages and
78	  avoids a potential TLB penalty. The downside is an increase in
79	  alignment and potentially wasted space. Turn on this option if
80	  performance is more important than memory pressure.
81
82	  If in doubt, say N.
83
84config DEBUG_EFI
85	depends on EFI && DEBUG_INFO
86	bool "UEFI debugging"
87	help
88	  Enable this option to include EFI specific debugging features into
89	  the kernel that are only useful when using a debug build of the
90	  UEFI firmware
91
92config ARM64_RELOC_TEST
93	depends on m
94	tristate "Relocation testing module"
95
96source "drivers/hwtracing/coresight/Kconfig"
97