[linux-2.6-block.git] / arch / arm64 / 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"
Commit	Line	Data
8c2c3df3	1
4ddb9bf8 LA	2	config ARM64_PTDUMP_CORE
	3	def_bool n
	4
	5	config ARM64_PTDUMP_DEBUGFS
c9465b4e LA	6	bool "Export kernel pagetable layout to userspace via debugfs"
c9465b4e LA	7	depends on DEBUG_KERNEL
4ddb9bf8	8	select ARM64_PTDUMP_CORE
c9465b4e LA	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.
604c8e67 MR	16
604c8e67 MR	17	If in doubt, say N.
c9465b4e	18
ec45d1cf WD	19	config 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
da57a369 MR	27	config 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
1404d6f1 LA	42	config 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
da141706	71	config DEBUG_ALIGN_RODATA
0f5bf6d0	72	depends on STRICT_KERNEL_RWX
da141706 LA	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
604c8e67	82	If in doubt, say N.
da141706	83
757b435a AB	84	config 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
214fad55 AB	92	config ARM64_RELOC_TEST
	93	depends on m
	94	tristate "Relocation testing module"
	95
01081f5a	96	source "drivers/hwtracing/coresight/Kconfig"