tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
1config HAVE_ARCH_KMEMCHECK
2 bool
3
4menuconfig KMEMCHECK
5 bool "kmemcheck: trap use of uninitialized memory"
6 depends on DEBUG_KERNEL
7 depends on !X86_USE_3DNOW
8 depends on SLUB || SLAB
9 depends on !CC_OPTIMIZE_FOR_SIZE
10 depends on !FUNCTION_TRACER
11 select FRAME_POINTER
12 select STACKTRACE
13 default n
14 help
15 This option enables tracing of dynamically allocated kernel memory
16 to see if memory is used before it has been given an initial value.
17 Be aware that this requires half of your memory for bookkeeping and
18 will insert extra code at *every* read and write to tracked memory
19 thus slow down the kernel code (but user code is unaffected).
20
21 The kernel may be started with kmemcheck=0 or kmemcheck=1 to disable
22 or enable kmemcheck at boot-time. If the kernel is started with
23 kmemcheck=0, the large memory and CPU overhead is not incurred.
24
25choice
26 prompt "kmemcheck: default mode at boot"
27 depends on KMEMCHECK
28 default KMEMCHECK_ONESHOT_BY_DEFAULT
29 help
30 This option controls the default behaviour of kmemcheck when the
31 kernel boots and no kmemcheck= parameter is given.
32
33config KMEMCHECK_DISABLED_BY_DEFAULT
34 bool "disabled"
35 depends on KMEMCHECK
36
37config KMEMCHECK_ENABLED_BY_DEFAULT
38 bool "enabled"
39 depends on KMEMCHECK
40
41config KMEMCHECK_ONESHOT_BY_DEFAULT
42 bool "one-shot"
43 depends on KMEMCHECK
44 help
45 In one-shot mode, only the first error detected is reported before
46 kmemcheck is disabled.
47
48endchoice
49
50config KMEMCHECK_QUEUE_SIZE
51 int "kmemcheck: error queue size"
52 depends on KMEMCHECK
53 default 64
54 help
55 Select the maximum number of errors to store in the queue. Since
56 errors can occur virtually anywhere and in any context, we need a
57 temporary storage area which is guarantueed not to generate any
58 other faults. The queue will be emptied as soon as a tasklet may
59 be scheduled. If the queue is full, new error reports will be
60 lost.
61
62config KMEMCHECK_SHADOW_COPY_SHIFT
63 int "kmemcheck: shadow copy size (5 => 32 bytes, 6 => 64 bytes)"
64 depends on KMEMCHECK
65 range 2 8
66 default 5
67 help
68 Select the number of shadow bytes to save along with each entry of
69 the queue. These bytes indicate what parts of an allocation are
70 initialized, uninitialized, etc. and will be displayed when an
71 error is detected to help the debugging of a particular problem.
72
73config KMEMCHECK_PARTIAL_OK
74 bool "kmemcheck: allow partially uninitialized memory"
75 depends on KMEMCHECK
76 default y
77 help
78 This option works around certain GCC optimizations that produce
79 32-bit reads from 16-bit variables where the upper 16 bits are
80 thrown away afterwards. This may of course also hide some real
81 bugs.
82
83config KMEMCHECK_BITOPS_OK
84 bool "kmemcheck: allow bit-field manipulation"
85 depends on KMEMCHECK
86 default n
87 help
88 This option silences warnings that would be generated for bit-field
89 accesses where not all the bits are initialized at the same time.
90 This may also hide some real bugs.
91