kmemcheck: make kconfig accessible for other architectures
The Kconfig options of kmemcheck are hidden under arch/x86 which makes porting
to other architectures harder. To fix that, move the Kconfig bits to
lib/Kconfig.kmemcheck and introduce a CONFIG_HAVE_ARCH_KMEMCHECK config option
that architectures can define.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
[rebased for mainline inclusion]
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
diff --git a/lib/Kconfig.kmemcheck b/lib/Kconfig.kmemcheck
new file mode 100644
index 0000000..603c81b
--- /dev/null
+++ b/lib/Kconfig.kmemcheck
@@ -0,0 +1,91 @@
+config HAVE_ARCH_KMEMCHECK
+ bool
+
+menuconfig KMEMCHECK
+ bool "kmemcheck: trap use of uninitialized memory"
+ depends on DEBUG_KERNEL
+ depends on !X86_USE_3DNOW
+ depends on SLUB || SLAB
+ depends on !CC_OPTIMIZE_FOR_SIZE
+ depends on !FUNCTION_TRACER
+ select FRAME_POINTER
+ select STACKTRACE
+ default n
+ help
+ This option enables tracing of dynamically allocated kernel memory
+ to see if memory is used before it has been given an initial value.
+ Be aware that this requires half of your memory for bookkeeping and
+ will insert extra code at *every* read and write to tracked memory
+ thus slow down the kernel code (but user code is unaffected).
+
+ The kernel may be started with kmemcheck=0 or kmemcheck=1 to disable
+ or enable kmemcheck at boot-time. If the kernel is started with
+ kmemcheck=0, the large memory and CPU overhead is not incurred.
+
+choice
+ prompt "kmemcheck: default mode at boot"
+ depends on KMEMCHECK
+ default KMEMCHECK_ONESHOT_BY_DEFAULT
+ help
+ This option controls the default behaviour of kmemcheck when the
+ kernel boots and no kmemcheck= parameter is given.
+
+config KMEMCHECK_DISABLED_BY_DEFAULT
+ bool "disabled"
+ depends on KMEMCHECK
+
+config KMEMCHECK_ENABLED_BY_DEFAULT
+ bool "enabled"
+ depends on KMEMCHECK
+
+config KMEMCHECK_ONESHOT_BY_DEFAULT
+ bool "one-shot"
+ depends on KMEMCHECK
+ help
+ In one-shot mode, only the first error detected is reported before
+ kmemcheck is disabled.
+
+endchoice
+
+config KMEMCHECK_QUEUE_SIZE
+ int "kmemcheck: error queue size"
+ depends on KMEMCHECK
+ default 64
+ help
+ Select the maximum number of errors to store in the queue. Since
+ errors can occur virtually anywhere and in any context, we need a
+ temporary storage area which is guarantueed not to generate any
+ other faults. The queue will be emptied as soon as a tasklet may
+ be scheduled. If the queue is full, new error reports will be
+ lost.
+
+config KMEMCHECK_SHADOW_COPY_SHIFT
+ int "kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)"
+ depends on KMEMCHECK
+ range 2 8
+ default 5
+ help
+ Select the number of shadow bytes to save along with each entry of
+ the queue. These bytes indicate what parts of an allocation are
+ initialized, uninitialized, etc. and will be displayed when an
+ error is detected to help the debugging of a particular problem.
+
+config KMEMCHECK_PARTIAL_OK
+ bool "kmemcheck: allow partially uninitialized memory"
+ depends on KMEMCHECK
+ default y
+ help
+ This option works around certain GCC optimizations that produce
+ 32-bit reads from 16-bit variables where the upper 16 bits are
+ thrown away afterwards. This may of course also hide some real
+ bugs.
+
+config KMEMCHECK_BITOPS_OK
+ bool "kmemcheck: allow bit-field manipulation"
+ depends on KMEMCHECK
+ default n
+ help
+ This option silences warnings that would be generated for bit-field
+ accesses where not all the bits are initialized at the same time.
+ This may also hide some real bugs.
+