1menu "Kernel hacking"
2
3source "lib/Kconfig.debug"
4
5config FRAME_POINTER
6	bool
7	default y
8
9config 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
21config 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
35config 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
43config 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
58config 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
69config 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
79config DEBUG_ALIGN_RODATA
80	depends on DEBUG_RODATA && !ARM64_64K_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
92source "drivers/hwtracing/coresight/Kconfig"
93
94endmenu
95