menu "Kernel hacking"

config TRACE_IRQFLAGS_SUPPORT
	def_bool n

source "lib/Kconfig.debug"

config STRICT_DEVMEM
	bool "Filter access to /dev/mem"
	help
	  If this option is disabled, you allow userspace (root) access to all
	  of memory, including kernel and userspace memory. Accidental
	  access to this is obviously disastrous, but specific access can
	  be used by people debugging the kernel. Note that with PAT support
	  enabled, even in this case there are restrictions on /dev/mem
	  use due to the cache aliasing requirements.

	  If this option is switched on, the /dev/mem file only allows
	  userspace access to PCI space and the BIOS code and data regions.
	  This is sufficient for dosemu and X and all common users of
	  /dev/mem.

	  If in doubt, say Y.

config EARLY_PRINTK
	bool "Early printk" if EMBEDDED
	default y
	help
	  Write kernel log output directly into the VGA buffer or to a serial
	  port.

	  This is useful for kernel debugging when your machine crashes very
	  early before the console code is initialized. For normal operation
	  it is not recommended because it looks ugly and doesn't cooperate
	  with klogd/syslogd or the X server. You should normally N here,
	  unless you want to debug such a crash.

config DEBUG_STACKOVERFLOW
	bool "Check for stack overflows"
	depends on DEBUG_KERNEL
	help
	  This option will cause messages to be printed if free stack space
	  drops below a certain limit.

config DEBUG_STACK_USAGE
	bool "Stack utilization instrumentation"
	depends on DEBUG_KERNEL
	help
	  Enables the display of the minimum amount of free stack which each
	  task has ever had available in the sysrq-T and sysrq-P debug output.

	  This option will slow down process creation somewhat.

config DEBUG_PAGEALLOC
	bool "Debug page memory allocations"
	depends on DEBUG_KERNEL
	help
	  Unmap pages from the kernel linear mapping after free_pages().
	  This results in a large slowdown, but helps to find certain types
	  of memory corruptions.


config X86_PTDUMP
	bool "Export kernel pagetable layout to userspace via debugfs"
	depends on DEBUG_KERNEL
	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 DEBUG_NX_TEST
	tristate "Testcase for the NX non-executable stack feature"
	depends on DEBUG_KERNEL && m
	help
	  This option enables a testcase for the CPU NX capability
	  and the software setup of this feature.
	  If in doubt, say "N"

config 16KSTACKS
	bool "Use 16Kb for kernel stacks instead of 8Kb"
	help
	  If you say Y here the kernel will use a  16Kb stacksize for the
	  kernel stack attached to each process/thread. The default is 8K.
	  This increases the resident kernel footprint and will cause less
	  threads to run on the system and also increase the pressure
	  on the VM subsystem for higher order allocations.

config MMIOTRACE
	bool "Memory mapped IO tracing"
	depends on DEBUG_KERNEL && PCI
	select TRACING
	select MMIOTRACE_HOOKS
	help
	  Mmiotrace traces Memory Mapped I/O access and is meant for
	  debugging and reverse engineering. It is called from the ioremap
	  implementation and works via page faults. Tracing is disabled by
	  default and can be enabled at run-time.

	  See Documentation/tracers/mmiotrace.txt.
	  If you are not helping to develop drivers, say N.

config OPTIMIZE_INLINING
	bool "Allow gcc to uninline functions marked 'inline'"
	help
	  This option determines if the kernel forces gcc to inline the functions
	  developers have marked 'inline'. Doing so takes away freedom from gcc to
	  do what it thinks is best, which is desirable for the gcc 3.x series of
	  compilers. The gcc 4.x series have a rewritten inlining algorithm and
	  disabling this option will generate a smaller kernel there. Hopefully
	  this algorithm is so good that allowing gcc4 to make the decision can
	  become the default in the future, until then this option is there to
	  test gcc for this.

	  If unsure, say N.

endmenu