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 && DEBUG_KERNEL && X86_32
+ bool "Early printk" if EMBEDDED
default y
- help
+ ---help---
Write kernel log output directly into the VGA buffer or to a serial
port.
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"
+ 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
- help
+ ---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
+ ---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.
-comment "Page alloc debug is incompatible with Software Suspend on i386"
- depends on DEBUG_KERNEL && HIBERNATION
- depends on X86_32
+config DEBUG_PER_CPU_MAPS
+ bool "Debug access to per_cpu maps"
+ depends on DEBUG_KERNEL
+ depends on SMP
+ ---help---
+ Say Y to verify that the per_cpu map being accessed has
+ been setup. Adds a fair amount of code to kernel memory
+ and decreases performance.
-config DEBUG_PAGEALLOC
- bool "Debug page memory allocations"
- depends on DEBUG_KERNEL && !HIBERNATION && !HUGETLBFS
- depends on X86_32
- 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.
+ 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
depends on DEBUG_KERNEL
- help
+ ---help---
Mark the kernel read-only data as write-protected in the pagetables,
in order to catch accidental (and incorrect) writes to such const
- data. This option may have a slight performance impact because a
- portion of the kernel code won't be covered by a 2MB TLB anymore.
- If in doubt, say "N".
+ data. This is recommended so that we can catch kernel bugs sooner.
+ If in doubt, say "Y".
+
+config DEBUG_RODATA_TEST
+ bool "Testcase for the DEBUG_RODATA feature"
+ depends on DEBUG_RODATA
+ default y
+ ---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
+ ---help---
If you say Y here the kernel will use a 4Kb stacksize for the
kernel stack attached to each process/thread. This facilitates
running more threads on a system and also reduces the pressure
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
depends on X86_32
- help
+ ---help---
This option allows trapping of rare doublefault exceptions that
would otherwise cause a system to silently reboot. Disabling this
option saves about 4k and might cause you much additional grey
bool "Enable IOMMU debugging"
depends on GART_IOMMU && DEBUG_KERNEL
depends on X86_64
- help
+ ---help---
Force the IOMMU to on even when you have less than 4GB of
memory and add debugging code. On overflow always panic. And
allow to enable IOMMU leak tracing. Can be disabled at boot
options. See Documentation/x86_64/boot-options.txt for more
details.
+config IOMMU_STRESS
+ bool "Enable IOMMU stress-test mode"
+ ---help---
+ This option disables various optimizations in IOMMU related
+ code to do real stress testing of the IOMMU code. This option
+ will cause a performance drop and should only be enabled for
+ testing.
+
config IOMMU_LEAK
bool "IOMMU leak tracing"
- depends on DEBUG_KERNEL
- depends on IOMMU_DEBUG
- help
+ depends on IOMMU_DEBUG && DMA_API_DEBUG
+ ---help---
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 HAVE_MMIOTRACE_SUPPORT
+ def_bool y
+
+config X86_DECODER_SELFTEST
+ bool "x86 instruction decoder selftest"
+ depends on DEBUG_KERNEL && KPROBES
+ ---help---
+ Perform x86 instruction decoder selftests at build time.
+ This option is useful for checking the sanity of x86 instruction
+ decoder code.
+ If unsure, say "N".
+
#
# 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]"
- help
+ ---help---
This is the traditional Linux IO delay used for in/out_p.
It is the most tested hence safest selection here.
config IO_DELAY_0XED
bool "port 0xed based port-IO delay"
- help
+ ---help---
Use port 0xed as the IO delay. This frees up port 0x80 which is
often used as a hardware-debug port.
config IO_DELAY_UDELAY
bool "udelay based port-IO delay"
- help
+ ---help---
Use udelay(2) as the IO delay method. This provides the delay
while not having any side-effect on the IO port space.
config IO_DELAY_NONE
bool "no port-IO delay"
- help
+ ---help---
No port-IO delay. Will break on old boxes that require port-IO
delay for certain operations. Should work on most new machines.
default IO_DELAY_TYPE_NONE
endif
+config DEBUG_BOOT_PARAMS
+ bool "Debug boot parameters"
+ depends on DEBUG_KERNEL
+ depends on DEBUG_FS
+ ---help---
+ This option will cause struct boot_params to be exported via debugfs.
+
+config CPA_DEBUG
+ bool "CPA self-test code"
+ depends on DEBUG_KERNEL
+ ---help---
+ 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
+ enabling this option will generate a smaller kernel there. Hopefully
+ this algorithm is so good that allowing gcc 4.x and above to make the
+ decision will become the default in the future. Until then this option
+ is there to test gcc for this.
+
+ If unsure, say N.
+
+config DEBUG_STRICT_USER_COPY_CHECKS
+ bool "Strict copy size checks"
+ depends on DEBUG_KERNEL && !TRACE_BRANCH_PROFILING
+ ---help---
+ Enabling this option turns a certain set of sanity checks for user
+ copy operations into compile time failures.
+
+ The copy_from_user() etc checks are there to help test if there
+ are sufficient security checks on the length argument of
+ the copy operation, by having gcc prove that the argument is
+ within bounds.
+
+ If unsure, or if you run an older (pre 4.4) gcc, say N.
+
endmenu
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff