1 # SPDX-License-Identifier: GPL-2.0-only
4 menu "printk and dmesg options"
7 bool "Show timing information on printks"
10 Selecting this option causes time stamps of the printk()
11 messages to be added to the output of the syslog() system
12 call and at the console.
14 The timestamp is always recorded internally, and exported
15 to /dev/kmsg. This flag just specifies if the timestamp should
16 be included, not that the timestamp is recorded.
18 The behavior is also controlled by the kernel command line
19 parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
22 bool "Show caller information on printks"
25 Selecting this option causes printk() to add a caller "thread id" (if
26 in task context) or a caller "processor id" (if not in task context)
29 This option is intended for environments where multiple threads
30 concurrently call printk() for many times, for it is difficult to
31 interpret without knowing where these lines (or sometimes individual
32 line which was divided into multiple lines due to race) came from.
34 Since toggling after boot makes the code racy, currently there is
35 no option to enable/disable at the kernel command line parameter or
38 config CONSOLE_LOGLEVEL_DEFAULT
39 int "Default console loglevel (1-15)"
43 Default loglevel to determine what will be printed on the console.
45 Setting a default here is equivalent to passing in loglevel=<x> in
46 the kernel bootargs. loglevel=<x> continues to override whatever
47 value is specified here as well.
49 Note: This does not affect the log level of un-prefixed printk()
50 usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
53 config CONSOLE_LOGLEVEL_QUIET
54 int "quiet console loglevel (1-15)"
58 loglevel to use when "quiet" is passed on the kernel commandline.
60 When "quiet" is passed on the kernel commandline this loglevel
61 will be used as the loglevel. IOW passing "quiet" will be the
62 equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
64 config MESSAGE_LOGLEVEL_DEFAULT
65 int "Default message log level (1-7)"
69 Default log level for printk statements with no specified priority.
71 This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
72 that are auditing their logs closely may want to set it to a lower
75 Note: This does not affect what message level gets printed on the console
76 by default. To change that, use loglevel=<x> in the kernel bootargs,
77 or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
79 config BOOT_PRINTK_DELAY
80 bool "Delay each boot printk message by N milliseconds"
81 depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
83 This build option allows you to read kernel boot messages
84 by inserting a short delay after each one. The delay is
85 specified in milliseconds on the kernel command line,
88 It is likely that you would also need to use "lpj=M" to preset
89 the "loops per jiffie" value.
90 See a previous boot log for the "lpj" value to use for your
91 system, and then set "lpj=M" before setting "boot_delay=N".
92 NOTE: Using this option may adversely affect SMP systems.
93 I.e., processors other than the first one may not boot up.
94 BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
95 what it believes to be lockup conditions.
98 bool "Enable dynamic printk() support"
101 depends on (DEBUG_FS || PROC_FS)
102 select DYNAMIC_DEBUG_CORE
105 Compiles debug level messages into the kernel, which would not
106 otherwise be available at runtime. These messages can then be
107 enabled/disabled based on various levels of scope - per source file,
108 function, module, format string, and line number. This mechanism
109 implicitly compiles in all pr_debug() and dev_dbg() calls, which
110 enlarges the kernel text size by about 2%.
112 If a source file is compiled with DEBUG flag set, any
113 pr_debug() calls in it are enabled by default, but can be
114 disabled at runtime as below. Note that DEBUG flag is
115 turned on by many CONFIG_*DEBUG* options.
119 Dynamic debugging is controlled via the 'dynamic_debug/control' file,
120 which is contained in the 'debugfs' filesystem or procfs.
121 Thus, the debugfs or procfs filesystem must first be mounted before
122 making use of this feature.
123 We refer the control file as: <debugfs>/dynamic_debug/control. This
124 file contains a list of the debug statements that can be enabled. The
125 format for each line of the file is:
127 filename:lineno [module]function flags format
129 filename : source file of the debug statement
130 lineno : line number of the debug statement
131 module : module that contains the debug statement
132 function : function that contains the debug statement
133 flags : '=p' means the line is turned 'on' for printing
134 format : the format used for the debug statement
138 nullarbor:~ # cat <debugfs>/dynamic_debug/control
139 # filename:lineno [module]function flags format
140 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
141 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
142 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
146 // enable the message at line 1603 of file svcsock.c
147 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
148 <debugfs>/dynamic_debug/control
150 // enable all the messages in file svcsock.c
151 nullarbor:~ # echo -n 'file svcsock.c +p' >
152 <debugfs>/dynamic_debug/control
154 // enable all the messages in the NFS server module
155 nullarbor:~ # echo -n 'module nfsd +p' >
156 <debugfs>/dynamic_debug/control
158 // enable all 12 messages in the function svc_process()
159 nullarbor:~ # echo -n 'func svc_process +p' >
160 <debugfs>/dynamic_debug/control
162 // disable all 12 messages in the function svc_process()
163 nullarbor:~ # echo -n 'func svc_process -p' >
164 <debugfs>/dynamic_debug/control
166 See Documentation/admin-guide/dynamic-debug-howto.rst for additional
169 config DYNAMIC_DEBUG_CORE
170 bool "Enable core function of dynamic debug support"
172 depends on (DEBUG_FS || PROC_FS)
174 Enable core functional support of dynamic debug. It is useful
175 when you want to tie dynamic debug to your kernel modules with
176 DYNAMIC_DEBUG_MODULE defined for each of them, especially for
177 the case of embedded system where the kernel image size is
178 sensitive for people.
180 config SYMBOLIC_ERRNAME
181 bool "Support symbolic error names in printf"
184 If you say Y here, the kernel's printf implementation will
185 be able to print symbolic error names such as ENOSPC instead
186 of the number 28. It makes the kernel image slightly larger
187 (about 3KB), but can make the kernel logs easier to read.
189 config DEBUG_BUGVERBOSE
190 bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
191 depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
194 Say Y here to make BUG() panics output the file name and line number
195 of the BUG call as well as the EIP and oops trace. This aids
196 debugging but costs about 70-100K of memory.
198 endmenu # "printk and dmesg options"
200 menu "Compile-time checks and compiler options"
203 bool "Compile the kernel with debug info"
204 depends on DEBUG_KERNEL && !COMPILE_TEST
206 If you say Y here the resulting kernel image will include
207 debugging info resulting in a larger kernel image.
208 This adds debug symbols to the kernel and modules (gcc -g), and
209 is needed if you intend to use kernel crashdump or binary object
210 tools like crash, kgdb, LKCD, gdb, etc on the kernel.
211 Say Y here only if you plan to debug the kernel.
215 config DEBUG_INFO_REDUCED
216 bool "Reduce debugging information"
217 depends on DEBUG_INFO
219 If you say Y here gcc is instructed to generate less debugging
220 information for structure types. This means that tools that
221 need full debugging information (like kgdb or systemtap) won't
222 be happy. But if you merely need debugging information to
223 resolve line numbers there is no loss. Advantage is that
224 build directory object sizes shrink dramatically over a full
225 DEBUG_INFO build and compile times are reduced too.
226 Only works with newer gcc versions.
228 config DEBUG_INFO_COMPRESSED
229 bool "Compressed debugging information"
230 depends on DEBUG_INFO
231 depends on $(cc-option,-gz=zlib)
232 depends on $(ld-option,--compress-debug-sections=zlib)
234 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
235 5.0+, binutils 2.26+, and zlib.
237 Users of dpkg-deb via scripts/package/builddeb may find an increase in
238 size of their debug .deb packages with this config set, due to the
239 debug info being compressed with zlib, then the object files being
240 recompressed with a different compression scheme. But this is still
241 preferable to setting $KDEB_COMPRESS to "none" which would be even
244 config DEBUG_INFO_SPLIT
245 bool "Produce split debuginfo in .dwo files"
246 depends on DEBUG_INFO
247 depends on $(cc-option,-gsplit-dwarf)
249 Generate debug info into separate .dwo files. This significantly
250 reduces the build directory size for builds with DEBUG_INFO,
251 because it stores the information only once on disk in .dwo
252 files instead of multiple times in object files and executables.
253 In addition the debug information is also compressed.
255 Requires recent gcc (4.7+) and recent gdb/binutils.
256 Any tool that packages or reads debug information would need
257 to know about the .dwo files and include them.
258 Incompatible with older versions of ccache.
260 config DEBUG_INFO_DWARF4
261 bool "Generate dwarf4 debuginfo"
262 depends on DEBUG_INFO
263 depends on $(cc-option,-gdwarf-4)
265 Generate dwarf4 debug info. This requires recent versions
266 of gcc and gdb. It makes the debug information larger.
267 But it significantly improves the success of resolving
268 variables in gdb on optimized code.
270 config DEBUG_INFO_BTF
271 bool "Generate BTF typeinfo"
272 depends on DEBUG_INFO
273 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
274 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
276 Generate deduplicated BTF type information from DWARF debug info.
277 Turning this on expects presence of pahole tool, which will convert
278 DWARF type info into equivalent deduplicated BTF type info.
281 bool "Provide GDB scripts for kernel debugging"
282 depends on DEBUG_INFO
284 This creates the required links to GDB helper scripts in the
285 build directory. If you load vmlinux into gdb, the helper
286 scripts will be automatically imported by gdb as well, and
287 additional functions are available to analyze a Linux kernel
288 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
291 config ENABLE_MUST_CHECK
292 bool "Enable __must_check logic"
295 Enable the __must_check logic in the kernel build. Disable this to
296 suppress the "warning: ignoring return value of 'foo', declared with
297 attribute warn_unused_result" messages.
300 int "Warn for stack frames larger than"
302 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
303 default 1280 if (!64BIT && PARISC)
304 default 1024 if (!64BIT && !PARISC)
305 default 2048 if 64BIT
307 Tell gcc to warn at build time for stack frames larger than this.
308 Setting this too low will cause a lot of warnings.
309 Setting it to 0 disables the warning.
311 config STRIP_ASM_SYMS
312 bool "Strip assembler-generated symbols during link"
315 Strip internal assembler-generated symbols during a link (symbols
316 that look like '.Lxxx') so they don't pollute the output of
317 get_wchan() and suchlike.
320 bool "Generate readable assembler code"
321 depends on DEBUG_KERNEL
323 Disable some compiler optimizations that tend to generate human unreadable
324 assembler output. This may make the kernel slightly slower, but it helps
325 to keep kernel developers who have to stare a lot at assembler listings
328 config HEADERS_INSTALL
329 bool "Install uapi headers to usr/include"
332 This option will install uapi headers (headers exported to user-space)
333 into the usr/include directory for use during the kernel build.
334 This is unneeded for building the kernel itself, but needed for some
335 user-space program samples. It is also needed by some features such
336 as uapi header sanity checks.
338 config DEBUG_SECTION_MISMATCH
339 bool "Enable full Section mismatch analysis"
341 The section mismatch analysis checks if there are illegal
342 references from one section to another section.
343 During linktime or runtime, some sections are dropped;
344 any use of code/data previously in these sections would
345 most likely result in an oops.
346 In the code, functions and variables are annotated with
347 __init,, etc. (see the full list in include/linux/init.h),
348 which results in the code/data being placed in specific sections.
349 The section mismatch analysis is always performed after a full
350 kernel build, and enabling this option causes the following
351 additional step to occur:
352 - Add the option -fno-inline-functions-called-once to gcc commands.
353 When inlining a function annotated with __init in a non-init
354 function, we would lose the section information and thus
355 the analysis would not catch the illegal reference.
356 This option tells gcc to inline less (but it does result in
359 config SECTION_MISMATCH_WARN_ONLY
360 bool "Make section mismatch errors non-fatal"
363 If you say N here, the build process will fail if there are any
364 section mismatch, instead of just throwing warnings.
369 # Select this config option from the architecture Kconfig, if it
370 # is preferred to always offer frame pointers as a config
371 # option on the architecture (regardless of KERNEL_DEBUG):
373 config ARCH_WANT_FRAME_POINTERS
377 bool "Compile the kernel with frame pointers"
378 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
379 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
381 If you say Y here the resulting kernel image will be slightly
382 larger and slower, but it gives very useful debugging information
383 in case of kernel bugs. (precise oopses/stacktraces/warnings)
385 config STACK_VALIDATION
386 bool "Compile-time stack metadata validation"
387 depends on HAVE_STACK_VALIDATION
390 Add compile-time checks to validate stack metadata, including frame
391 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
392 that runtime stack traces are more reliable.
394 This is also a prerequisite for generation of ORC unwind data, which
395 is needed for CONFIG_UNWINDER_ORC.
397 For more information, see
398 tools/objtool/Documentation/stack-validation.txt.
400 config VMLINUX_VALIDATION
402 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
405 config DEBUG_FORCE_WEAK_PER_CPU
406 bool "Force weak per-cpu definitions"
407 depends on DEBUG_KERNEL
409 s390 and alpha require percpu variables in modules to be
410 defined weak to work around addressing range issue which
411 puts the following two restrictions on percpu variable
414 1. percpu symbols must be unique whether static or not
415 2. percpu variables can't be defined inside a function
417 To ensure that generic code follows the above rules, this
418 option forces all percpu variables to be defined as weak.
420 endmenu # "Compiler options"
422 menu "Generic Kernel Debugging Instruments"
425 bool "Magic SysRq key"
428 If you say Y here, you will have some control over the system even
429 if the system crashes for example during kernel debugging (e.g., you
430 will be able to flush the buffer cache to disk, reboot the system
431 immediately or dump some status information). This is accomplished
432 by pressing various keys while holding SysRq (Alt+PrintScreen). It
433 also works on a serial console (on PC hardware at least), if you
434 send a BREAK and then within 5 seconds a command keypress. The
435 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
436 Don't say Y unless you really know what this hack does.
438 config MAGIC_SYSRQ_DEFAULT_ENABLE
439 hex "Enable magic SysRq key functions by default"
440 depends on MAGIC_SYSRQ
443 Specifies which SysRq key functions are enabled by default.
444 This may be set to 1 or 0 to enable or disable them all, or
445 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
447 config MAGIC_SYSRQ_SERIAL
448 bool "Enable magic SysRq key over serial"
449 depends on MAGIC_SYSRQ
452 Many embedded boards have a disconnected TTL level serial which can
453 generate some garbage that can lead to spurious false sysrq detects.
454 This option allows you to decide whether you want to enable the
457 config MAGIC_SYSRQ_SERIAL_SEQUENCE
458 string "Char sequence that enables magic SysRq over serial"
459 depends on MAGIC_SYSRQ_SERIAL
462 Specifies a sequence of characters that can follow BREAK to enable
463 SysRq on a serial console.
465 If unsure, leave an empty string and the option will not be enabled.
468 bool "Debug Filesystem"
470 debugfs is a virtual file system that kernel developers use to put
471 debugging files into. Enable this option to be able to read and
472 write to these files.
474 For detailed documentation on the debugfs API, see
475 Documentation/filesystems/.
479 source "lib/Kconfig.kgdb"
481 source "lib/Kconfig.ubsan"
486 bool "Kernel debugging"
488 Say Y here if you are developing drivers or trying to debug and
489 identify kernel problems.
492 bool "Miscellaneous debug code"
494 depends on DEBUG_KERNEL
496 Say Y here if you need to enable miscellaneous debug code that should
497 be under a more specific debug option but isn't.
500 menu "Memory Debugging"
502 source "mm/Kconfig.debug"
505 bool "Debug object operations"
506 depends on DEBUG_KERNEL
508 If you say Y here, additional code will be inserted into the
509 kernel to track the life time of various objects and validate
510 the operations on those objects.
512 config DEBUG_OBJECTS_SELFTEST
513 bool "Debug objects selftest"
514 depends on DEBUG_OBJECTS
516 This enables the selftest of the object debug code.
518 config DEBUG_OBJECTS_FREE
519 bool "Debug objects in freed memory"
520 depends on DEBUG_OBJECTS
522 This enables checks whether a k/v free operation frees an area
523 which contains an object which has not been deactivated
524 properly. This can make kmalloc/kfree-intensive workloads
527 config DEBUG_OBJECTS_TIMERS
528 bool "Debug timer objects"
529 depends on DEBUG_OBJECTS
531 If you say Y here, additional code will be inserted into the
532 timer routines to track the life time of timer objects and
533 validate the timer operations.
535 config DEBUG_OBJECTS_WORK
536 bool "Debug work objects"
537 depends on DEBUG_OBJECTS
539 If you say Y here, additional code will be inserted into the
540 work queue routines to track the life time of work objects and
541 validate the work operations.
543 config DEBUG_OBJECTS_RCU_HEAD
544 bool "Debug RCU callbacks objects"
545 depends on DEBUG_OBJECTS
547 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
549 config DEBUG_OBJECTS_PERCPU_COUNTER
550 bool "Debug percpu counter objects"
551 depends on DEBUG_OBJECTS
553 If you say Y here, additional code will be inserted into the
554 percpu counter routines to track the life time of percpu counter
555 objects and validate the percpu counter operations.
557 config DEBUG_OBJECTS_ENABLE_DEFAULT
558 int "debug_objects bootup default value (0-1)"
561 depends on DEBUG_OBJECTS
563 Debug objects boot parameter default value
566 bool "Debug slab memory allocations"
567 depends on DEBUG_KERNEL && SLAB
569 Say Y here to have the kernel do limited verification on memory
570 allocation as well as poisoning memory on free to catch use of freed
571 memory. This can make kmalloc/kfree-intensive workloads much slower.
574 bool "SLUB debugging on by default"
575 depends on SLUB && SLUB_DEBUG
578 Boot with debugging on by default. SLUB boots by default with
579 the runtime debug capabilities switched off. Enabling this is
580 equivalent to specifying the "slub_debug" parameter on boot.
581 There is no support for more fine grained debug control like
582 possible with slub_debug=xxx. SLUB debugging may be switched
583 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
588 bool "Enable SLUB performance statistics"
589 depends on SLUB && SYSFS
591 SLUB statistics are useful to debug SLUBs allocation behavior in
592 order find ways to optimize the allocator. This should never be
593 enabled for production use since keeping statistics slows down
594 the allocator by a few percentage points. The slabinfo command
595 supports the determination of the most active slabs to figure
596 out which slabs are relevant to a particular load.
597 Try running: slabinfo -DA
599 config HAVE_DEBUG_KMEMLEAK
602 config DEBUG_KMEMLEAK
603 bool "Kernel memory leak detector"
604 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
606 select STACKTRACE if STACKTRACE_SUPPORT
610 Say Y here if you want to enable the memory leak
611 detector. The memory allocation/freeing is traced in a way
612 similar to the Boehm's conservative garbage collector, the
613 difference being that the orphan objects are not freed but
614 only shown in /sys/kernel/debug/kmemleak. Enabling this
615 feature will introduce an overhead to memory
616 allocations. See Documentation/dev-tools/kmemleak.rst for more
619 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
620 of finding leaks due to the slab objects poisoning.
622 In order to access the kmemleak file, debugfs needs to be
623 mounted (usually at /sys/kernel/debug).
625 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
626 int "Kmemleak memory pool size"
627 depends on DEBUG_KMEMLEAK
631 Kmemleak must track all the memory allocations to avoid
632 reporting false positives. Since memory may be allocated or
633 freed before kmemleak is fully initialised, use a static pool
634 of metadata objects to track such callbacks. After kmemleak is
635 fully initialised, this memory pool acts as an emergency one
636 if slab allocations fail.
638 config DEBUG_KMEMLEAK_TEST
639 tristate "Simple test for the kernel memory leak detector"
640 depends on DEBUG_KMEMLEAK && m
642 This option enables a module that explicitly leaks memory.
646 config DEBUG_KMEMLEAK_DEFAULT_OFF
647 bool "Default kmemleak to off"
648 depends on DEBUG_KMEMLEAK
650 Say Y here to disable kmemleak by default. It can then be enabled
651 on the command line via kmemleak=on.
653 config DEBUG_KMEMLEAK_AUTO_SCAN
654 bool "Enable kmemleak auto scan thread on boot up"
656 depends on DEBUG_KMEMLEAK
658 Depending on the cpu, kmemleak scan may be cpu intensive and can
659 stall user tasks at times. This option enables/disables automatic
660 kmemleak scan at boot up.
662 Say N here to disable kmemleak auto scan thread to stop automatic
663 scanning. Disabling this option disables automatic reporting of
668 config DEBUG_STACK_USAGE
669 bool "Stack utilization instrumentation"
670 depends on DEBUG_KERNEL && !IA64
672 Enables the display of the minimum amount of free stack which each
673 task has ever had available in the sysrq-T and sysrq-P debug output.
675 This option will slow down process creation somewhat.
677 config SCHED_STACK_END_CHECK
678 bool "Detect stack corruption on calls to schedule()"
679 depends on DEBUG_KERNEL
682 This option checks for a stack overrun on calls to schedule().
683 If the stack end location is found to be over written always panic as
684 the content of the corrupted region can no longer be trusted.
685 This is to ensure no erroneous behaviour occurs which could result in
686 data corruption or a sporadic crash at a later stage once the region
687 is examined. The runtime overhead introduced is minimal.
689 config ARCH_HAS_DEBUG_VM_PGTABLE
692 An architecture should select this when it can successfully
693 build and run DEBUG_VM_PGTABLE.
697 depends on DEBUG_KERNEL
699 Enable this to turn on extended checks in the virtual-memory system
700 that may impact performance.
704 config DEBUG_VM_VMACACHE
705 bool "Debug VMA caching"
708 Enable this to turn on VMA caching debug information. Doing so
709 can cause significant overhead, so only enable it in non-production
715 bool "Debug VM red-black trees"
718 Enable VM red-black tree debugging information and extra validations.
722 config DEBUG_VM_PGFLAGS
723 bool "Debug page-flags operations"
726 Enables extra validation on page flags operations.
730 config DEBUG_VM_PGTABLE
731 bool "Debug arch page table for semantics compliance"
733 depends on ARCH_HAS_DEBUG_VM_PGTABLE
734 default y if DEBUG_VM
736 This option provides a debug method which can be used to test
737 architecture page table helper functions on various platforms in
738 verifying if they comply with expected generic MM semantics. This
739 will help architecture code in making sure that any changes or
740 new additions of these helpers still conform to expected
741 semantics of the generic MM. Platforms will have to opt in for
742 this through ARCH_HAS_DEBUG_VM_PGTABLE.
746 config ARCH_HAS_DEBUG_VIRTUAL
750 bool "Debug VM translations"
751 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
753 Enable some costly sanity checks in virtual to page code. This can
754 catch mistakes with virt_to_page() and friends.
758 config DEBUG_NOMMU_REGIONS
759 bool "Debug the global anon/private NOMMU mapping region tree"
760 depends on DEBUG_KERNEL && !MMU
762 This option causes the global tree of anonymous and private mapping
763 regions to be regularly checked for invalid topology.
765 config DEBUG_MEMORY_INIT
766 bool "Debug memory initialisation" if EXPERT
769 Enable this for additional checks during memory initialisation.
770 The sanity checks verify aspects of the VM such as the memory model
771 and other information provided by the architecture. Verbose
772 information will be printed at KERN_DEBUG loglevel depending
773 on the mminit_loglevel= command-line option.
777 config MEMORY_NOTIFIER_ERROR_INJECT
778 tristate "Memory hotplug notifier error injection module"
779 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
781 This option provides the ability to inject artificial errors to
782 memory hotplug notifier chain callbacks. It is controlled through
783 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
785 If the notifier call chain should be failed with some events
786 notified, write the error code to "actions/<notifier event>/error".
788 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
790 # cd /sys/kernel/debug/notifier-error-inject/memory
791 # echo -12 > actions/MEM_GOING_OFFLINE/error
792 # echo offline > /sys/devices/system/memory/memoryXXX/state
793 bash: echo: write error: Cannot allocate memory
795 To compile this code as a module, choose M here: the module will
796 be called memory-notifier-error-inject.
800 config DEBUG_PER_CPU_MAPS
801 bool "Debug access to per_cpu maps"
802 depends on DEBUG_KERNEL
805 Say Y to verify that the per_cpu map being accessed has
806 been set up. This adds a fair amount of code to kernel memory
807 and decreases performance.
812 bool "Highmem debugging"
813 depends on DEBUG_KERNEL && HIGHMEM
815 This option enables additional error checking for high memory
816 systems. Disable for production systems.
818 config HAVE_DEBUG_STACKOVERFLOW
821 config DEBUG_STACKOVERFLOW
822 bool "Check for stack overflows"
823 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
825 Say Y here if you want to check for overflows of kernel, IRQ
826 and exception stacks (if your architecture uses them). This
827 option will show detailed messages if free stack space drops
828 below a certain limit.
830 These kinds of bugs usually occur when call-chains in the
831 kernel get too deep, especially when interrupts are
834 Use this in cases where you see apparently random memory
835 corruption, especially if it appears in 'struct thread_info'
837 If in doubt, say "N".
839 source "lib/Kconfig.kasan"
841 endmenu # "Memory Debugging"
844 bool "Debug shared IRQ handlers"
845 depends on DEBUG_KERNEL
847 Enable this to generate a spurious interrupt as soon as a shared
848 interrupt handler is registered, and just before one is deregistered.
849 Drivers ought to be able to handle interrupts coming in at those
850 points; some don't and need to be caught.
852 menu "Debug Oops, Lockups and Hangs"
857 Say Y here to enable the kernel to panic when it oopses. This
858 has the same effect as setting oops=panic on the kernel command
861 This feature is useful to ensure that the kernel does not do
862 anything erroneous after an oops which could result in data
863 corruption or other issues.
867 config PANIC_ON_OOPS_VALUE
870 default 0 if !PANIC_ON_OOPS
871 default 1 if PANIC_ON_OOPS
877 Set the timeout value (in seconds) until a reboot occurs when the
878 the kernel panics. If n = 0, then we wait forever. A timeout
879 value n > 0 will wait n seconds before rebooting, while a timeout
880 value n < 0 will reboot immediately.
882 config LOCKUP_DETECTOR
885 config SOFTLOCKUP_DETECTOR
886 bool "Detect Soft Lockups"
887 depends on DEBUG_KERNEL && !S390
888 select LOCKUP_DETECTOR
890 Say Y here to enable the kernel to act as a watchdog to detect
893 Softlockups are bugs that cause the kernel to loop in kernel
894 mode for more than 20 seconds, without giving other tasks a
895 chance to run. The current stack trace is displayed upon
896 detection and the system will stay locked up.
898 config BOOTPARAM_SOFTLOCKUP_PANIC
899 bool "Panic (Reboot) On Soft Lockups"
900 depends on SOFTLOCKUP_DETECTOR
902 Say Y here to enable the kernel to panic on "soft lockups",
903 which are bugs that cause the kernel to loop in kernel
904 mode for more than 20 seconds (configurable using the watchdog_thresh
905 sysctl), without giving other tasks a chance to run.
907 The panic can be used in combination with panic_timeout,
908 to cause the system to reboot automatically after a
909 lockup has been detected. This feature is useful for
910 high-availability systems that have uptime guarantees and
911 where a lockup must be resolved ASAP.
915 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
917 depends on SOFTLOCKUP_DETECTOR
919 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
920 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
922 config HARDLOCKUP_DETECTOR_PERF
924 select SOFTLOCKUP_DETECTOR
927 # Enables a timestamp based low pass filter to compensate for perf based
928 # hard lockup detection which runs too fast due to turbo modes.
930 config HARDLOCKUP_CHECK_TIMESTAMP
934 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
935 # lockup detector rather than the perf based detector.
937 config HARDLOCKUP_DETECTOR
938 bool "Detect Hard Lockups"
939 depends on DEBUG_KERNEL && !S390
940 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
941 select LOCKUP_DETECTOR
942 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
943 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
945 Say Y here to enable the kernel to act as a watchdog to detect
948 Hardlockups are bugs that cause the CPU to loop in kernel mode
949 for more than 10 seconds, without letting other interrupts have a
950 chance to run. The current stack trace is displayed upon detection
951 and the system will stay locked up.
953 config BOOTPARAM_HARDLOCKUP_PANIC
954 bool "Panic (Reboot) On Hard Lockups"
955 depends on HARDLOCKUP_DETECTOR
957 Say Y here to enable the kernel to panic on "hard lockups",
958 which are bugs that cause the kernel to loop in kernel
959 mode with interrupts disabled for more than 10 seconds (configurable
960 using the watchdog_thresh sysctl).
964 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
966 depends on HARDLOCKUP_DETECTOR
968 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
969 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
971 config DETECT_HUNG_TASK
972 bool "Detect Hung Tasks"
973 depends on DEBUG_KERNEL
974 default SOFTLOCKUP_DETECTOR
976 Say Y here to enable the kernel to detect "hung tasks",
977 which are bugs that cause the task to be stuck in
978 uninterruptible "D" state indefinitely.
980 When a hung task is detected, the kernel will print the
981 current stack trace (which you should report), but the
982 task will stay in uninterruptible state. If lockdep is
983 enabled then all held locks will also be reported. This
984 feature has negligible overhead.
986 config DEFAULT_HUNG_TASK_TIMEOUT
987 int "Default timeout for hung task detection (in seconds)"
988 depends on DETECT_HUNG_TASK
991 This option controls the default timeout (in seconds) used
992 to determine when a task has become non-responsive and should
995 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
996 sysctl or by writing a value to
997 /proc/sys/kernel/hung_task_timeout_secs.
999 A timeout of 0 disables the check. The default is two minutes.
1000 Keeping the default should be fine in most cases.
1002 config BOOTPARAM_HUNG_TASK_PANIC
1003 bool "Panic (Reboot) On Hung Tasks"
1004 depends on DETECT_HUNG_TASK
1006 Say Y here to enable the kernel to panic on "hung tasks",
1007 which are bugs that cause the kernel to leave a task stuck
1008 in uninterruptible "D" state.
1010 The panic can be used in combination with panic_timeout,
1011 to cause the system to reboot automatically after a
1012 hung task has been detected. This feature is useful for
1013 high-availability systems that have uptime guarantees and
1014 where a hung tasks must be resolved ASAP.
1018 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1020 depends on DETECT_HUNG_TASK
1022 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1023 default 1 if BOOTPARAM_HUNG_TASK_PANIC
1026 bool "Detect Workqueue Stalls"
1027 depends on DEBUG_KERNEL
1029 Say Y here to enable stall detection on workqueues. If a
1030 worker pool doesn't make forward progress on a pending work
1031 item for over a given amount of time, 30s by default, a
1032 warning message is printed along with dump of workqueue
1033 state. This can be configured through kernel parameter
1034 "workqueue.watchdog_thresh" and its sysfs counterpart.
1037 tristate "Test module to generate lockups"
1039 This builds the "test_lockup" module that helps to make sure
1040 that watchdogs and lockup detectors are working properly.
1042 Depending on module parameters it could emulate soft or hard
1043 lockup, "hung task", or locking arbitrary lock for a long time.
1044 Also it could generate series of lockups with cooling-down periods.
1048 endmenu # "Debug lockups and hangs"
1050 menu "Scheduler Debugging"
1053 bool "Collect scheduler debugging info"
1054 depends on DEBUG_KERNEL && PROC_FS
1057 If you say Y here, the /proc/sched_debug file will be provided
1058 that can help debug the scheduler. The runtime overhead of this
1066 bool "Collect scheduler statistics"
1067 depends on DEBUG_KERNEL && PROC_FS
1070 If you say Y here, additional code will be inserted into the
1071 scheduler and related routines to collect statistics about
1072 scheduler behavior and provide them in /proc/schedstat. These
1073 stats may be useful for both tuning and debugging the scheduler
1074 If you aren't debugging the scheduler or trying to tune a specific
1075 application, you can say N to avoid the very slight overhead
1080 config DEBUG_TIMEKEEPING
1081 bool "Enable extra timekeeping sanity checking"
1083 This option will enable additional timekeeping sanity checks
1084 which may be helpful when diagnosing issues where timekeeping
1085 problems are suspected.
1087 This may include checks in the timekeeping hotpaths, so this
1088 option may have a (very small) performance impact to some
1093 config DEBUG_PREEMPT
1094 bool "Debug preemptible kernel"
1095 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1098 If you say Y here then the kernel will use a debug variant of the
1099 commonly used smp_processor_id() function and will print warnings
1100 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1101 will detect preemption count underflows.
1103 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1105 config LOCK_DEBUGGING_SUPPORT
1107 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1110 config PROVE_LOCKING
1111 bool "Lock debugging: prove locking correctness"
1112 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1114 select DEBUG_SPINLOCK
1115 select DEBUG_MUTEXES
1116 select DEBUG_RT_MUTEXES if RT_MUTEXES
1118 select DEBUG_WW_MUTEX_SLOWPATH
1119 select DEBUG_LOCK_ALLOC
1120 select TRACE_IRQFLAGS
1123 This feature enables the kernel to prove that all locking
1124 that occurs in the kernel runtime is mathematically
1125 correct: that under no circumstance could an arbitrary (and
1126 not yet triggered) combination of observed locking
1127 sequences (on an arbitrary number of CPUs, running an
1128 arbitrary number of tasks and interrupt contexts) cause a
1131 In short, this feature enables the kernel to report locking
1132 related deadlocks before they actually occur.
1134 The proof does not depend on how hard and complex a
1135 deadlock scenario would be to trigger: how many
1136 participant CPUs, tasks and irq-contexts would be needed
1137 for it to trigger. The proof also does not depend on
1138 timing: if a race and a resulting deadlock is possible
1139 theoretically (no matter how unlikely the race scenario
1140 is), it will be proven so and will immediately be
1141 reported by the kernel (once the event is observed that
1142 makes the deadlock theoretically possible).
1144 If a deadlock is impossible (i.e. the locking rules, as
1145 observed by the kernel, are mathematically correct), the
1146 kernel reports nothing.
1148 NOTE: this feature can also be enabled for rwlocks, mutexes
1149 and rwsems - in which case all dependencies between these
1150 different locking variants are observed and mapped too, and
1151 the proof of observed correctness is also maintained for an
1152 arbitrary combination of these separate locking variants.
1154 For more details, see Documentation/locking/lockdep-design.rst.
1156 config PROVE_RAW_LOCK_NESTING
1157 bool "Enable raw_spinlock - spinlock nesting checks"
1158 depends on PROVE_LOCKING
1161 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1162 that the lock nesting rules for PREEMPT_RT enabled kernels are
1165 NOTE: There are known nesting problems. So if you enable this
1166 option expect lockdep splats until these problems have been fully
1167 addressed which is work in progress. This config switch allows to
1168 identify and analyze these problems. It will be removed and the
1169 check permanentely enabled once the main issues have been fixed.
1171 If unsure, select N.
1174 bool "Lock usage statistics"
1175 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1177 select DEBUG_SPINLOCK
1178 select DEBUG_MUTEXES
1179 select DEBUG_RT_MUTEXES if RT_MUTEXES
1180 select DEBUG_LOCK_ALLOC
1183 This feature enables tracking lock contention points
1185 For more details, see Documentation/locking/lockstat.rst
1187 This also enables lock events required by "perf lock",
1189 If you want to use "perf lock", you also need to turn on
1190 CONFIG_EVENT_TRACING.
1192 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1193 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1195 config DEBUG_RT_MUTEXES
1196 bool "RT Mutex debugging, deadlock detection"
1197 depends on DEBUG_KERNEL && RT_MUTEXES
1199 This allows rt mutex semantics violations and rt mutex related
1200 deadlocks (lockups) to be detected and reported automatically.
1202 config DEBUG_SPINLOCK
1203 bool "Spinlock and rw-lock debugging: basic checks"
1204 depends on DEBUG_KERNEL
1205 select UNINLINE_SPIN_UNLOCK
1207 Say Y here and build SMP to catch missing spinlock initialization
1208 and certain other kinds of spinlock errors commonly made. This is
1209 best used in conjunction with the NMI watchdog so that spinlock
1210 deadlocks are also debuggable.
1212 config DEBUG_MUTEXES
1213 bool "Mutex debugging: basic checks"
1214 depends on DEBUG_KERNEL
1216 This feature allows mutex semantics violations to be detected and
1219 config DEBUG_WW_MUTEX_SLOWPATH
1220 bool "Wait/wound mutex debugging: Slowpath testing"
1221 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1222 select DEBUG_LOCK_ALLOC
1223 select DEBUG_SPINLOCK
1224 select DEBUG_MUTEXES
1226 This feature enables slowpath testing for w/w mutex users by
1227 injecting additional -EDEADLK wound/backoff cases. Together with
1228 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1229 will test all possible w/w mutex interface abuse with the
1230 exception of simply not acquiring all the required locks.
1231 Note that this feature can introduce significant overhead, so
1232 it really should not be enabled in a production or distro kernel,
1233 even a debug kernel. If you are a driver writer, enable it. If
1234 you are a distro, do not.
1237 bool "RW Semaphore debugging: basic checks"
1238 depends on DEBUG_KERNEL
1240 This debugging feature allows mismatched rw semaphore locks
1241 and unlocks to be detected and reported.
1243 config DEBUG_LOCK_ALLOC
1244 bool "Lock debugging: detect incorrect freeing of live locks"
1245 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1246 select DEBUG_SPINLOCK
1247 select DEBUG_MUTEXES
1248 select DEBUG_RT_MUTEXES if RT_MUTEXES
1251 This feature will check whether any held lock (spinlock, rwlock,
1252 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1253 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1254 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1255 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1256 held during task exit.
1260 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1262 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1266 config LOCKDEP_SMALL
1269 config DEBUG_LOCKDEP
1270 bool "Lock dependency engine debugging"
1271 depends on DEBUG_KERNEL && LOCKDEP
1273 If you say Y here, the lock dependency engine will do
1274 additional runtime checks to debug itself, at the price
1275 of more runtime overhead.
1277 config DEBUG_ATOMIC_SLEEP
1278 bool "Sleep inside atomic section checking"
1279 select PREEMPT_COUNT
1280 depends on DEBUG_KERNEL
1281 depends on !ARCH_NO_PREEMPT
1283 If you say Y here, various routines which may sleep will become very
1284 noisy if they are called inside atomic sections: when a spinlock is
1285 held, inside an rcu read side critical section, inside preempt disabled
1286 sections, inside an interrupt, etc...
1288 config DEBUG_LOCKING_API_SELFTESTS
1289 bool "Locking API boot-time self-tests"
1290 depends on DEBUG_KERNEL
1292 Say Y here if you want the kernel to run a short self-test during
1293 bootup. The self-test checks whether common types of locking bugs
1294 are detected by debugging mechanisms or not. (if you disable
1295 lock debugging then those bugs wont be detected of course.)
1296 The following locking APIs are covered: spinlocks, rwlocks,
1299 config LOCK_TORTURE_TEST
1300 tristate "torture tests for locking"
1301 depends on DEBUG_KERNEL
1304 This option provides a kernel module that runs torture tests
1305 on kernel locking primitives. The kernel module may be built
1306 after the fact on the running kernel to be tested, if desired.
1308 Say Y here if you want kernel locking-primitive torture tests
1309 to be built into the kernel.
1310 Say M if you want these torture tests to build as a module.
1311 Say N if you are unsure.
1313 config WW_MUTEX_SELFTEST
1314 tristate "Wait/wound mutex selftests"
1316 This option provides a kernel module that runs tests on the
1317 on the struct ww_mutex locking API.
1319 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1320 with this test harness.
1322 Say M if you want these self tests to build as a module.
1323 Say N if you are unsure.
1325 endmenu # lock debugging
1327 config TRACE_IRQFLAGS
1330 Enables hooks to interrupt enabling and disabling for
1331 either tracing or lock debugging.
1334 bool "Stack backtrace support"
1335 depends on STACKTRACE_SUPPORT
1337 This option causes the kernel to create a /proc/pid/stack for
1338 every process, showing its current stack trace.
1339 It is also used by various kernel debugging features that require
1340 stack trace generation.
1342 config WARN_ALL_UNSEEDED_RANDOM
1343 bool "Warn for all uses of unseeded randomness"
1346 Some parts of the kernel contain bugs relating to their use of
1347 cryptographically secure random numbers before it's actually possible
1348 to generate those numbers securely. This setting ensures that these
1349 flaws don't go unnoticed, by enabling a message, should this ever
1350 occur. This will allow people with obscure setups to know when things
1351 are going wrong, so that they might contact developers about fixing
1354 Unfortunately, on some models of some architectures getting
1355 a fully seeded CRNG is extremely difficult, and so this can
1356 result in dmesg getting spammed for a surprisingly long
1357 time. This is really bad from a security perspective, and
1358 so architecture maintainers really need to do what they can
1359 to get the CRNG seeded sooner after the system is booted.
1360 However, since users cannot do anything actionable to
1361 address this, by default the kernel will issue only a single
1362 warning for the first use of unseeded randomness.
1364 Say Y here if you want to receive warnings for all uses of
1365 unseeded randomness. This will be of use primarily for
1366 those developers interested in improving the security of
1367 Linux kernels running on their architecture (or
1370 config DEBUG_KOBJECT
1371 bool "kobject debugging"
1372 depends on DEBUG_KERNEL
1374 If you say Y here, some extra kobject debugging messages will be sent
1377 config DEBUG_KOBJECT_RELEASE
1378 bool "kobject release debugging"
1379 depends on DEBUG_OBJECTS_TIMERS
1381 kobjects are reference counted objects. This means that their
1382 last reference count put is not predictable, and the kobject can
1383 live on past the point at which a driver decides to drop it's
1384 initial reference to the kobject gained on allocation. An
1385 example of this would be a struct device which has just been
1388 However, some buggy drivers assume that after such an operation,
1389 the memory backing the kobject can be immediately freed. This
1390 goes completely against the principles of a refcounted object.
1392 If you say Y here, the kernel will delay the release of kobjects
1393 on the last reference count to improve the visibility of this
1394 kind of kobject release bug.
1396 config HAVE_DEBUG_BUGVERBOSE
1399 menu "Debug kernel data structures"
1402 bool "Debug linked list manipulation"
1403 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1405 Enable this to turn on extended checks in the linked-list
1411 bool "Debug priority linked list manipulation"
1412 depends on DEBUG_KERNEL
1414 Enable this to turn on extended checks in the priority-ordered
1415 linked-list (plist) walking routines. This checks the entire
1416 list multiple times during each manipulation.
1421 bool "Debug SG table operations"
1422 depends on DEBUG_KERNEL
1424 Enable this to turn on checks on scatter-gather tables. This can
1425 help find problems with drivers that do not properly initialize
1430 config DEBUG_NOTIFIERS
1431 bool "Debug notifier call chains"
1432 depends on DEBUG_KERNEL
1434 Enable this to turn on sanity checking for notifier call chains.
1435 This is most useful for kernel developers to make sure that
1436 modules properly unregister themselves from notifier chains.
1437 This is a relatively cheap check but if you care about maximum
1440 config BUG_ON_DATA_CORRUPTION
1441 bool "Trigger a BUG when data corruption is detected"
1444 Select this option if the kernel should BUG when it encounters
1445 data corruption in kernel memory structures when they get checked
1452 config DEBUG_CREDENTIALS
1453 bool "Debug credential management"
1454 depends on DEBUG_KERNEL
1456 Enable this to turn on some debug checking for credential
1457 management. The additional code keeps track of the number of
1458 pointers from task_structs to any given cred struct, and checks to
1459 see that this number never exceeds the usage count of the cred
1462 Furthermore, if SELinux is enabled, this also checks that the
1463 security pointer in the cred struct is never seen to be invalid.
1467 source "kernel/rcu/Kconfig.debug"
1469 config DEBUG_WQ_FORCE_RR_CPU
1470 bool "Force round-robin CPU selection for unbound work items"
1471 depends on DEBUG_KERNEL
1474 Workqueue used to implicitly guarantee that work items queued
1475 without explicit CPU specified are put on the local CPU. This
1476 guarantee is no longer true and while local CPU is still
1477 preferred work items may be put on foreign CPUs. Kernel
1478 parameter "workqueue.debug_force_rr_cpu" is added to force
1479 round-robin CPU selection to flush out usages which depend on the
1480 now broken guarantee. This config option enables the debug
1481 feature by default. When enabled, memory and cache locality will
1484 config DEBUG_BLOCK_EXT_DEVT
1485 bool "Force extended block device numbers and spread them"
1486 depends on DEBUG_KERNEL
1490 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1491 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1492 YOU ARE DOING. Distros, please enable this and fix whatever
1495 Conventionally, block device numbers are allocated from
1496 predetermined contiguous area. However, extended block area
1497 may introduce non-contiguous block device numbers. This
1498 option forces most block device numbers to be allocated from
1499 the extended space and spreads them to discover kernel or
1500 userland code paths which assume predetermined contiguous
1501 device number allocation.
1503 Note that turning on this debug option shuffles all the
1504 device numbers for all IDE and SCSI devices including libata
1505 ones, so root partition specified using device number
1506 directly (via rdev or root=MAJ:MIN) won't work anymore.
1507 Textual device names (root=/dev/sdXn) will continue to work.
1509 Say N if you are unsure.
1511 config CPU_HOTPLUG_STATE_CONTROL
1512 bool "Enable CPU hotplug state control"
1513 depends on DEBUG_KERNEL
1514 depends on HOTPLUG_CPU
1517 Allows to write steps between "offline" and "online" to the CPUs
1518 sysfs target file so states can be stepped granular. This is a debug
1519 option for now as the hotplug machinery cannot be stopped and
1520 restarted at arbitrary points yet.
1522 Say N if your are unsure.
1525 bool "Latency measuring infrastructure"
1526 depends on DEBUG_KERNEL
1527 depends on STACKTRACE_SUPPORT
1529 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1536 Enable this option if you want to use the LatencyTOP tool
1537 to find out which userspace is blocking on what kernel operations.
1539 source "kernel/trace/Kconfig"
1541 config PROVIDE_OHCI1394_DMA_INIT
1542 bool "Remote debugging over FireWire early on boot"
1543 depends on PCI && X86
1545 If you want to debug problems which hang or crash the kernel early
1546 on boot and the crashing machine has a FireWire port, you can use
1547 this feature to remotely access the memory of the crashed machine
1548 over FireWire. This employs remote DMA as part of the OHCI1394
1549 specification which is now the standard for FireWire controllers.
1551 With remote DMA, you can monitor the printk buffer remotely using
1552 firescope and access all memory below 4GB using fireproxy from gdb.
1553 Even controlling a kernel debugger is possible using remote DMA.
1557 If ohci1394_dma=early is used as boot parameter, it will initialize
1558 all OHCI1394 controllers which are found in the PCI config space.
1560 As all changes to the FireWire bus such as enabling and disabling
1561 devices cause a bus reset and thereby disable remote DMA for all
1562 devices, be sure to have the cable plugged and FireWire enabled on
1563 the debugging host before booting the debug target for debugging.
1565 This code (~1k) is freed after boot. By then, the firewire stack
1566 in charge of the OHCI-1394 controllers should be used instead.
1568 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1570 source "samples/Kconfig"
1572 source "lib/Kconfig.kcsan"
1574 config ARCH_HAS_DEVMEM_IS_ALLOWED
1577 config STRICT_DEVMEM
1578 bool "Filter access to /dev/mem"
1579 depends on MMU && DEVMEM
1580 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1581 default y if PPC || X86 || ARM64
1583 If this option is disabled, you allow userspace (root) access to all
1584 of memory, including kernel and userspace memory. Accidental
1585 access to this is obviously disastrous, but specific access can
1586 be used by people debugging the kernel. Note that with PAT support
1587 enabled, even in this case there are restrictions on /dev/mem
1588 use due to the cache aliasing requirements.
1590 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1591 file only allows userspace access to PCI space and the BIOS code and
1592 data regions. This is sufficient for dosemu and X and all common
1597 config IO_STRICT_DEVMEM
1598 bool "Filter I/O access to /dev/mem"
1599 depends on STRICT_DEVMEM
1601 If this option is disabled, you allow userspace (root) access to all
1602 io-memory regardless of whether a driver is actively using that
1603 range. Accidental access to this is obviously disastrous, but
1604 specific access can be used by people debugging kernel drivers.
1606 If this option is switched on, the /dev/mem file only allows
1607 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1608 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1609 if the driver using a given range cannot be disabled.
1613 menu "$(SRCARCH) Debugging"
1615 source "arch/$(SRCARCH)/Kconfig.debug"
1619 menu "Kernel Testing and Coverage"
1621 source "lib/kunit/Kconfig"
1623 config NOTIFIER_ERROR_INJECTION
1624 tristate "Notifier error injection"
1625 depends on DEBUG_KERNEL
1628 This option provides the ability to inject artificial errors to
1629 specified notifier chain callbacks. It is useful to test the error
1630 handling of notifier call chain failures.
1634 config PM_NOTIFIER_ERROR_INJECT
1635 tristate "PM notifier error injection module"
1636 depends on PM && NOTIFIER_ERROR_INJECTION
1637 default m if PM_DEBUG
1639 This option provides the ability to inject artificial errors to
1640 PM notifier chain callbacks. It is controlled through debugfs
1641 interface /sys/kernel/debug/notifier-error-inject/pm
1643 If the notifier call chain should be failed with some events
1644 notified, write the error code to "actions/<notifier event>/error".
1646 Example: Inject PM suspend error (-12 = -ENOMEM)
1648 # cd /sys/kernel/debug/notifier-error-inject/pm/
1649 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1650 # echo mem > /sys/power/state
1651 bash: echo: write error: Cannot allocate memory
1653 To compile this code as a module, choose M here: the module will
1654 be called pm-notifier-error-inject.
1658 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1659 tristate "OF reconfig notifier error injection module"
1660 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1662 This option provides the ability to inject artificial errors to
1663 OF reconfig notifier chain callbacks. It is controlled
1664 through debugfs interface under
1665 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1667 If the notifier call chain should be failed with some events
1668 notified, write the error code to "actions/<notifier event>/error".
1670 To compile this code as a module, choose M here: the module will
1671 be called of-reconfig-notifier-error-inject.
1675 config NETDEV_NOTIFIER_ERROR_INJECT
1676 tristate "Netdev notifier error injection module"
1677 depends on NET && NOTIFIER_ERROR_INJECTION
1679 This option provides the ability to inject artificial errors to
1680 netdevice notifier chain callbacks. It is controlled through debugfs
1681 interface /sys/kernel/debug/notifier-error-inject/netdev
1683 If the notifier call chain should be failed with some events
1684 notified, write the error code to "actions/<notifier event>/error".
1686 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1688 # cd /sys/kernel/debug/notifier-error-inject/netdev
1689 # echo -22 > actions/NETDEV_CHANGEMTU/error
1690 # ip link set eth0 mtu 1024
1691 RTNETLINK answers: Invalid argument
1693 To compile this code as a module, choose M here: the module will
1694 be called netdev-notifier-error-inject.
1698 config FUNCTION_ERROR_INJECTION
1700 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1702 config FAULT_INJECTION
1703 bool "Fault-injection framework"
1704 depends on DEBUG_KERNEL
1706 Provide fault-injection framework.
1707 For more details, see Documentation/fault-injection/.
1710 bool "Fault-injection capability for kmalloc"
1711 depends on FAULT_INJECTION
1712 depends on SLAB || SLUB
1714 Provide fault-injection capability for kmalloc.
1716 config FAIL_PAGE_ALLOC
1717 bool "Fault-injection capability for alloc_pages()"
1718 depends on FAULT_INJECTION
1720 Provide fault-injection capability for alloc_pages().
1722 config FAIL_MAKE_REQUEST
1723 bool "Fault-injection capability for disk IO"
1724 depends on FAULT_INJECTION && BLOCK
1726 Provide fault-injection capability for disk IO.
1728 config FAIL_IO_TIMEOUT
1729 bool "Fault-injection capability for faking disk interrupts"
1730 depends on FAULT_INJECTION && BLOCK
1732 Provide fault-injection capability on end IO handling. This
1733 will make the block layer "forget" an interrupt as configured,
1734 thus exercising the error handling.
1736 Only works with drivers that use the generic timeout handling,
1737 for others it wont do anything.
1740 bool "Fault-injection capability for futexes"
1742 depends on FAULT_INJECTION && FUTEX
1744 Provide fault-injection capability for futexes.
1746 config FAULT_INJECTION_DEBUG_FS
1747 bool "Debugfs entries for fault-injection capabilities"
1748 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1750 Enable configuration of fault-injection capabilities via debugfs.
1752 config FAIL_FUNCTION
1753 bool "Fault-injection capability for functions"
1754 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1756 Provide function-based fault-injection capability.
1757 This will allow you to override a specific function with a return
1758 with given return value. As a result, function caller will see
1759 an error value and have to handle it. This is useful to test the
1760 error handling in various subsystems.
1762 config FAIL_MMC_REQUEST
1763 bool "Fault-injection capability for MMC IO"
1764 depends on FAULT_INJECTION_DEBUG_FS && MMC
1766 Provide fault-injection capability for MMC IO.
1767 This will make the mmc core return data errors. This is
1768 useful to test the error handling in the mmc block device
1769 and to test how the mmc host driver handles retries from
1772 config FAULT_INJECTION_STACKTRACE_FILTER
1773 bool "stacktrace filter for fault-injection capabilities"
1774 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1777 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1779 Provide stacktrace filter for fault-injection capabilities
1781 config ARCH_HAS_KCOV
1784 An architecture should select this when it can successfully
1785 build and run with CONFIG_KCOV. This typically requires
1786 disabling instrumentation for some early boot code.
1788 config CC_HAS_SANCOV_TRACE_PC
1789 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1793 bool "Code coverage for fuzzing"
1794 depends on ARCH_HAS_KCOV
1795 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1797 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1799 KCOV exposes kernel code coverage information in a form suitable
1800 for coverage-guided fuzzing (randomized testing).
1802 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1803 different machines and across reboots. If you need stable PC values,
1804 disable RANDOMIZE_BASE.
1806 For more details, see Documentation/dev-tools/kcov.rst.
1808 config KCOV_ENABLE_COMPARISONS
1809 bool "Enable comparison operands collection by KCOV"
1811 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1813 KCOV also exposes operands of every comparison in the instrumented
1814 code along with operand sizes and PCs of the comparison instructions.
1815 These operands can be used by fuzzing engines to improve the quality
1816 of fuzzing coverage.
1818 config KCOV_INSTRUMENT_ALL
1819 bool "Instrument all code by default"
1823 If you are doing generic system call fuzzing (like e.g. syzkaller),
1824 then you will want to instrument the whole kernel and you should
1825 say y here. If you are doing more targeted fuzzing (like e.g.
1826 filesystem fuzzing with AFL) then you will want to enable coverage
1827 for more specific subsets of files, and should say n here.
1829 config KCOV_IRQ_AREA_SIZE
1830 hex "Size of interrupt coverage collection area in words"
1834 KCOV uses preallocated per-cpu areas to collect coverage from
1835 soft interrupts. This specifies the size of those areas in the
1836 number of unsigned long words.
1838 menuconfig RUNTIME_TESTING_MENU
1839 bool "Runtime Testing"
1842 if RUNTIME_TESTING_MENU
1845 tristate "Linux Kernel Dump Test Tool Module"
1848 This module enables testing of the different dumping mechanisms by
1849 inducing system failures at predefined crash points.
1850 If you don't need it: say N
1851 Choose M here to compile this code as a module. The module will be
1854 Documentation on how to use the module can be found in
1855 Documentation/fault-injection/provoke-crashes.rst
1857 config TEST_LIST_SORT
1858 tristate "Linked list sorting test"
1859 depends on DEBUG_KERNEL || m
1861 Enable this to turn on 'list_sort()' function test. This test is
1862 executed only once during system boot (so affects only boot time),
1863 or at module load time.
1867 config TEST_MIN_HEAP
1868 tristate "Min heap test"
1869 depends on DEBUG_KERNEL || m
1871 Enable this to turn on min heap function tests. This test is
1872 executed only once during system boot (so affects only boot time),
1873 or at module load time.
1878 tristate "Array-based sort test"
1879 depends on DEBUG_KERNEL || m
1881 This option enables the self-test function of 'sort()' at boot,
1882 or at module load time.
1886 config KPROBES_SANITY_TEST
1887 bool "Kprobes sanity tests"
1888 depends on DEBUG_KERNEL
1891 This option provides for testing basic kprobes functionality on
1892 boot. Samples of kprobe and kretprobe are inserted and
1893 verified for functionality.
1895 Say N if you are unsure.
1897 config BACKTRACE_SELF_TEST
1898 tristate "Self test for the backtrace code"
1899 depends on DEBUG_KERNEL
1901 This option provides a kernel module that can be used to test
1902 the kernel stack backtrace code. This option is not useful
1903 for distributions or general kernels, but only for kernel
1904 developers working on architecture code.
1906 Note that if you want to also test saved backtraces, you will
1907 have to enable STACKTRACE as well.
1909 Say N if you are unsure.
1912 tristate "Red-Black tree test"
1913 depends on DEBUG_KERNEL
1915 A benchmark measuring the performance of the rbtree library.
1916 Also includes rbtree invariant checks.
1918 config REED_SOLOMON_TEST
1919 tristate "Reed-Solomon library test"
1920 depends on DEBUG_KERNEL || m
1922 select REED_SOLOMON_ENC16
1923 select REED_SOLOMON_DEC16
1925 This option enables the self-test function of rslib at boot,
1926 or at module load time.
1930 config INTERVAL_TREE_TEST
1931 tristate "Interval tree test"
1932 depends on DEBUG_KERNEL
1933 select INTERVAL_TREE
1935 A benchmark measuring the performance of the interval tree library
1938 tristate "Per cpu operations test"
1939 depends on m && DEBUG_KERNEL
1941 Enable this option to build test module which validates per-cpu
1946 config ATOMIC64_SELFTEST
1947 tristate "Perform an atomic64_t self-test"
1949 Enable this option to test the atomic64_t functions at boot or
1950 at module load time.
1954 config ASYNC_RAID6_TEST
1955 tristate "Self test for hardware accelerated raid6 recovery"
1956 depends on ASYNC_RAID6_RECOV
1959 This is a one-shot self test that permutes through the
1960 recovery of all the possible two disk failure scenarios for a
1961 N-disk array. Recovery is performed with the asynchronous
1962 raid6 recovery routines, and will optionally use an offload
1963 engine if one is available.
1968 tristate "Test functions located in the hexdump module at runtime"
1970 config TEST_STRING_HELPERS
1971 tristate "Test functions located in the string_helpers module at runtime"
1974 tristate "Test strscpy*() family of functions at runtime"
1977 tristate "Test kstrto*() family of functions at runtime"
1980 tristate "Test printf() family of functions at runtime"
1983 tristate "Test bitmap_*() family of functions at runtime"
1985 Enable this option to test the bitmap functions at boot.
1989 config TEST_BITFIELD
1990 tristate "Test bitfield functions at runtime"
1992 Enable this option to test the bitfield functions at boot.
1997 tristate "Test functions located in the uuid module at runtime"
2000 tristate "Test the XArray code at runtime"
2002 config TEST_OVERFLOW
2003 tristate "Test check_*_overflow() functions at runtime"
2005 config TEST_RHASHTABLE
2006 tristate "Perform selftest on resizable hash table"
2008 Enable this option to test the rhashtable functions at boot.
2013 tristate "Perform selftest on hash functions"
2015 Enable this option to test the kernel's integer (<linux/hash.h>),
2016 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2017 hash functions on boot (or module load).
2019 This is intended to help people writing architecture-specific
2020 optimized versions. If unsure, say N.
2023 tristate "Perform selftest on IDA functions"
2026 tristate "Perform selftest on priority array manager"
2029 Enable this option to test priority array manager on boot
2034 config TEST_IRQ_TIMINGS
2035 bool "IRQ timings selftest"
2036 depends on IRQ_TIMINGS
2038 Enable this option to test the irq timings code on boot.
2043 tristate "Test module loading with 'hello world' module"
2046 This builds the "test_module" module that emits "Hello, world"
2047 on printk when loaded. It is designed to be used for basic
2048 evaluation of the module loading subsystem (for example when
2049 validating module verification). It lacks any extra dependencies,
2050 and will not normally be loaded by the system unless explicitly
2056 tristate "Test module for compilation of bitops operations"
2059 This builds the "test_bitops" module that is much like the
2060 TEST_LKM module except that it does a basic exercise of the
2061 set/clear_bit macros and get_count_order/long to make sure there are
2062 no compiler warnings from C=1 sparse checker or -Wextra
2063 compilations. It has no dependencies and doesn't run or load unless
2064 explicitly requested by name. for example: modprobe test_bitops.
2069 tristate "Test module for stress/performance analysis of vmalloc allocator"
2074 This builds the "test_vmalloc" module that should be used for
2075 stress and performance analysis. So, any new change for vmalloc
2076 subsystem can be evaluated from performance and stability point
2081 config TEST_USER_COPY
2082 tristate "Test user/kernel boundary protections"
2085 This builds the "test_user_copy" module that runs sanity checks
2086 on the copy_to/from_user infrastructure, making sure basic
2087 user/kernel boundary testing is working. If it fails to load,
2088 a regression has been detected in the user/kernel memory boundary
2094 tristate "Test BPF filter functionality"
2097 This builds the "test_bpf" module that runs various test vectors
2098 against the BPF interpreter or BPF JIT compiler depending on the
2099 current setting. This is in particular useful for BPF JIT compiler
2100 development, but also to run regression tests against changes in
2101 the interpreter code. It also enables test stubs for eBPF maps and
2102 verifier used by user space verifier testsuite.
2106 config TEST_BLACKHOLE_DEV
2107 tristate "Test blackhole netdev functionality"
2110 This builds the "test_blackhole_dev" module that validates the
2111 data path through this blackhole netdev.
2115 config FIND_BIT_BENCHMARK
2116 tristate "Test find_bit functions"
2118 This builds the "test_find_bit" module that measure find_*_bit()
2119 functions performance.
2123 config TEST_FIRMWARE
2124 tristate "Test firmware loading via userspace interface"
2125 depends on FW_LOADER
2127 This builds the "test_firmware" module that creates a userspace
2128 interface for testing firmware loading. This can be used to
2129 control the triggering of firmware loading without needing an
2130 actual firmware-using device. The contents can be rechecked by
2136 tristate "sysctl test driver"
2137 depends on PROC_SYSCTL
2139 This builds the "test_sysctl" module. This driver enables to test the
2140 proc sysctl interfaces available to drivers safely without affecting
2141 production knobs which might alter system functionality.
2145 config SYSCTL_KUNIT_TEST
2146 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2148 default KUNIT_ALL_TESTS
2150 This builds the proc sysctl unit test, which runs on boot.
2151 Tests the API contract and implementation correctness of sysctl.
2152 For more information on KUnit and unit tests in general please refer
2153 to the KUnit documentation in Documentation/dev-tools/kunit/.
2157 config LIST_KUNIT_TEST
2158 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2160 default KUNIT_ALL_TESTS
2162 This builds the linked list KUnit test suite.
2163 It tests that the API and basic functionality of the list_head type
2164 and associated macros.
2166 KUnit tests run during boot and output the results to the debug log
2167 in TAP format (http://testanything.org/). Only useful for kernel devs
2168 running the KUnit test harness, and not intended for inclusion into a
2171 For more information on KUnit and unit tests in general please refer
2172 to the KUnit documentation in Documentation/dev-tools/kunit/.
2176 config LINEAR_RANGES_TEST
2177 tristate "KUnit test for linear_ranges"
2179 select LINEAR_RANGES
2181 This builds the linear_ranges unit test, which runs on boot.
2182 Tests the linear_ranges logic correctness.
2183 For more information on KUnit and unit tests in general please refer
2184 to the KUnit documentation in Documentation/dev-tools/kunit/.
2189 tristate "udelay test driver"
2191 This builds the "udelay_test" module that helps to make sure
2192 that udelay() is working properly.
2196 config TEST_STATIC_KEYS
2197 tristate "Test static keys"
2200 Test the static key interfaces.
2205 tristate "kmod stress tester"
2207 depends on NETDEVICES && NET_CORE && INET # for TUN
2214 Test the kernel's module loading mechanism: kmod. kmod implements
2215 support to load modules using the Linux kernel's usermode helper.
2216 This test provides a series of tests against kmod.
2218 Although technically you can either build test_kmod as a module or
2219 into the kernel we disallow building it into the kernel since
2220 it stress tests request_module() and this will very likely cause
2221 some issues by taking over precious threads available from other
2222 module load requests, ultimately this could be fatal.
2226 tools/testing/selftests/kmod/kmod.sh --help
2230 config TEST_DEBUG_VIRTUAL
2231 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2232 depends on DEBUG_VIRTUAL
2234 Test the kernel's ability to detect incorrect calls to
2235 virt_to_phys() done against the non-linear part of the
2236 kernel's virtual address map.
2240 config TEST_MEMCAT_P
2241 tristate "Test memcat_p() helper function"
2243 Test the memcat_p() helper for correctly merging two
2244 pointer arrays together.
2248 config TEST_LIVEPATCH
2249 tristate "Test livepatching"
2251 depends on DYNAMIC_DEBUG
2252 depends on LIVEPATCH
2255 Test kernel livepatching features for correctness. The tests will
2256 load test modules that will be livepatched in various scenarios.
2258 To run all the livepatching tests:
2260 make -C tools/testing/selftests TARGETS=livepatch run_tests
2262 Alternatively, individual tests may be invoked:
2264 tools/testing/selftests/livepatch/test-callbacks.sh
2265 tools/testing/selftests/livepatch/test-livepatch.sh
2266 tools/testing/selftests/livepatch/test-shadow-vars.sh
2271 tristate "Perform selftest on object aggreration manager"
2275 Enable this option to test object aggregation manager on boot
2279 config TEST_STACKINIT
2280 tristate "Test level of stack variable initialization"
2282 Test if the kernel is zero-initializing stack variables and
2283 padding. Coverage is controlled by compiler flags,
2284 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2285 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2290 tristate "Test heap/page initialization"
2292 Test if the kernel is zero-initializing heap and page allocations.
2293 This can be useful to test init_on_alloc and init_on_free features.
2298 tristate "Test HMM (Heterogeneous Memory Management)"
2299 depends on TRANSPARENT_HUGEPAGE
2300 depends on DEVICE_PRIVATE
2304 This is a pseudo device driver solely for testing HMM.
2305 Say M here if you want to build the HMM test module.
2306 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2310 endif # RUNTIME_TESTING_MENU
2315 This option adds a kernel parameter 'memtest', which allows memtest
2317 memtest=0, mean disabled; -- default
2318 memtest=1, mean do 1 test pattern;
2320 memtest=17, mean do 17 test patterns.
2321 If you are unsure how to answer this question, answer N.
2325 config HYPERV_TESTING
2326 bool "Microsoft Hyper-V driver testing"
2328 depends on HYPERV && DEBUG_FS
2330 Select this option to enable Hyper-V vmbus testing.
2332 endmenu # "Kernel Testing and Coverage"
2334 endmenu # Kernel hacking