source "lib/Kconfig.debug"
-config NONPROMISC_DEVMEM
- bool "Disable promiscuous /dev/mem"
+config STRICT_DEVMEM
+ bool "Filter access to /dev/mem"
help
- The /dev/mem file by default 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. With this config
- option, you allow userspace access to all of memory, including
- kernel and userspace memory. Accidental access to this is
- obviously disasterous, but specific access can be used by people
- debugging the kernel.
+ 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
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
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
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
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
- default n
-
-config MMIOTRACE
- tristate "Memory mapped IO tracing"
- depends on DEBUG_KERNEL && RELAY && DEBUG_FS
- select MMIOTRACE_HOOKS
- default n
- help
- This will build a kernel module called mmiotrace.
- Making this a built-in is heavily discouraged.
-
- Mmiotrace traces Memory Mapped I/O access and is meant for debugging
- and reverse engineering. The kernel module offers wrapped
- versions of the ioremap family of functions. The driver to be traced
- must be modified to call these wrappers. A user space program is
- required to collect the MMIO data.
-
- See http://nouveau.freedesktop.org/wiki/MmioTrace
- If you are not helping to develop drivers, say N.
-
-config MMIOTRACE_TEST
- tristate "Test module for mmiotrace"
- depends on MMIOTRACE && m
- default n
- 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.
+config HAVE_MMIOTRACE_SUPPORT
+ def_bool y
#
# IO delay types:
config OPTIMIZE_INLINING
bool "Allow gcc to uninline functions marked 'inline'"
- depends on BROKEN
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.
+ 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.
endmenu