| 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 |
| |
