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 X86_VERBOSE_BOOTUP
+ bool "Enable verbose x86 bootup info messages"
+ default y
+ help
+ Enables the informational output from the decompression stage
+ (e.g. bzImage) of the boot. If you disable this you will still
+ see errors. Disable this if you want silent bootup.
+
config EARLY_PRINTK
bool "Early printk" if EMBEDDED
default y
with klogd/syslogd or the X server. You should normally N here,
unless you want to debug such a crash.
+config EARLY_PRINTK_DBGP
+ bool "Early printk via EHCI debug port"
+ default n
+ depends on EARLY_PRINTK && PCI
+ help
+ Write kernel log output directly into the EHCI debug 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. You need usb debug device.
+
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
This option will slow down process creation somewhat.
-comment "Page alloc debug is incompatible with Software Suspend on i386"
- depends on DEBUG_KERNEL && HIBERNATION
- depends on X86_32
-
config DEBUG_PAGEALLOC
bool "Debug page memory allocations"
- depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS
+ 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
config DEBUG_PER_CPU_MAPS
bool "Debug access to per_cpu maps"
depends on DEBUG_KERNEL
- depends on X86_64_SMP
+ depends on X86_SMP
default n
help
Say Y to verify that the per_cpu map being accessed has
Say N if unsure.
+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_RODATA
bool "Write protect kernel read-only data structures"
default y
data. This is recommended so that we can catch kernel bugs sooner.
If in doubt, say "Y".
+config DIRECT_GBPAGES
+ bool "Enable gbpages-mapped kernel pagetables"
+ depends on DEBUG_KERNEL && EXPERIMENTAL && X86_64
+ help
+ Enable gigabyte pages support (if the CPU supports it). This can
+ improve the kernel's performance a tiny bit by reducing TLB
+ pressure.
+
+ This is experimental code.
+
+ If in doubt, say "N".
+
+config DEBUG_RODATA_TEST
+ bool "Testcase for the DEBUG_RODATA feature"
+ depends on DEBUG_RODATA
+ help
+ This option enables a testcase for the DEBUG_RODATA
+ feature as well as for the change_page_attr() infrastructure.
+ 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 4KSTACKS
bool "Use 4Kb for kernel stacks instead of 8Kb"
- depends on DEBUG_KERNEL
depends on X86_32
help
If you say Y here the kernel will use a 4Kb stacksize for the
on the VM subsystem for higher order allocations. This option
will also use IRQ stacks to compensate for the reduced stackspace.
-config X86_FIND_SMP_CONFIG
- def_bool y
- depends on X86_LOCAL_APIC || X86_VOYAGER
- depends on X86_32
-
-config X86_MPPARSE
- def_bool y
- depends on (X86_32 && (X86_LOCAL_APIC && !X86_VISWS)) || X86_64
-
config DOUBLEFAULT
default y
bool "Enable doublefault exception handler" if EMBEDDED
Add a simple leak tracer to the IOMMU code. This is useful when you
are debugging a buggy device driver that leaks IOMMU mappings.
+config MMIOTRACE_HOOKS
+ bool
+
+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 MMIOTRACE_TEST
+ tristate "Test module for mmiotrace"
+ depends on MMIOTRACE && m
+ help
+ This is a dumb module for testing mmiotrace. It is very dangerous
+ as it will write garbage to IO memory starting at a given address.
+ However, it should be safe to use on e.g. unused portion of VRAM.
+
+ Say N, unless you absolutely know what you are doing.
+
#
# IO delay types:
#
choice
prompt "IO delay type"
- default IO_DELAY_0XED
+ default IO_DELAY_0X80
config IO_DELAY_0X80
bool "port 0x80 based port-IO delay [recommended]"
This option will cause struct boot_params to be exported via debugfs.
config CPA_DEBUG
- bool "CPA self test code"
+ bool "CPA self-test code"
depends on DEBUG_KERNEL
help
- Do change_page_attr self tests at boot.
+ Do change_page_attr() self-tests every 30 seconds.
+
+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
+