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 $(as-option,-Wa$(comma)--compress-debug-sections=zlib)
233 depends on $(ld-option,--compress-debug-sections=zlib)
235 Compress the debug information using zlib. Requires GCC 5.0+ or Clang
236 5.0+, binutils 2.26+, and zlib.
238 Users of dpkg-deb via scripts/package/builddeb may find an increase in
239 size of their debug .deb packages with this config set, due to the
240 debug info being compressed with zlib, then the object files being
241 recompressed with a different compression scheme. But this is still
242 preferable to setting $KDEB_COMPRESS to "none" which would be even
245 config DEBUG_INFO_SPLIT
246 bool "Produce split debuginfo in .dwo files"
247 depends on DEBUG_INFO
248 depends on $(cc-option,-gsplit-dwarf)
250 Generate debug info into separate .dwo files. This significantly
251 reduces the build directory size for builds with DEBUG_INFO,
252 because it stores the information only once on disk in .dwo
253 files instead of multiple times in object files and executables.
254 In addition the debug information is also compressed.
256 Requires recent gcc (4.7+) and recent gdb/binutils.
257 Any tool that packages or reads debug information would need
258 to know about the .dwo files and include them.
259 Incompatible with older versions of ccache.
261 config DEBUG_INFO_DWARF4
262 bool "Generate dwarf4 debuginfo"
263 depends on DEBUG_INFO
264 depends on $(cc-option,-gdwarf-4)
266 Generate dwarf4 debug info. This requires recent versions
267 of gcc and gdb. It makes the debug information larger.
268 But it significantly improves the success of resolving
269 variables in gdb on optimized code.
271 config DEBUG_INFO_BTF
272 bool "Generate BTF typeinfo"
273 depends on DEBUG_INFO
274 depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
275 depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
277 Generate deduplicated BTF type information from DWARF debug info.
278 Turning this on expects presence of pahole tool, which will convert
279 DWARF type info into equivalent deduplicated BTF type info.
282 bool "Provide GDB scripts for kernel debugging"
283 depends on DEBUG_INFO
285 This creates the required links to GDB helper scripts in the
286 build directory. If you load vmlinux into gdb, the helper
287 scripts will be automatically imported by gdb as well, and
288 additional functions are available to analyze a Linux kernel
289 instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
292 config ENABLE_MUST_CHECK
293 bool "Enable __must_check logic"
296 Enable the __must_check logic in the kernel build. Disable this to
297 suppress the "warning: ignoring return value of 'foo', declared with
298 attribute warn_unused_result" messages.
301 int "Warn for stack frames larger than"
303 default 2048 if GCC_PLUGIN_LATENT_ENTROPY
304 default 1280 if (!64BIT && PARISC)
305 default 1024 if (!64BIT && !PARISC)
306 default 2048 if 64BIT
308 Tell gcc to warn at build time for stack frames larger than this.
309 Setting this too low will cause a lot of warnings.
310 Setting it to 0 disables the warning.
312 config STRIP_ASM_SYMS
313 bool "Strip assembler-generated symbols during link"
316 Strip internal assembler-generated symbols during a link (symbols
317 that look like '.Lxxx') so they don't pollute the output of
318 get_wchan() and suchlike.
321 bool "Generate readable assembler code"
322 depends on DEBUG_KERNEL
324 Disable some compiler optimizations that tend to generate human unreadable
325 assembler output. This may make the kernel slightly slower, but it helps
326 to keep kernel developers who have to stare a lot at assembler listings
329 config HEADERS_INSTALL
330 bool "Install uapi headers to usr/include"
333 This option will install uapi headers (headers exported to user-space)
334 into the usr/include directory for use during the kernel build.
335 This is unneeded for building the kernel itself, but needed for some
336 user-space program samples. It is also needed by some features such
337 as uapi header sanity checks.
339 config DEBUG_SECTION_MISMATCH
340 bool "Enable full Section mismatch analysis"
342 The section mismatch analysis checks if there are illegal
343 references from one section to another section.
344 During linktime or runtime, some sections are dropped;
345 any use of code/data previously in these sections would
346 most likely result in an oops.
347 In the code, functions and variables are annotated with
348 __init,, etc. (see the full list in include/linux/init.h),
349 which results in the code/data being placed in specific sections.
350 The section mismatch analysis is always performed after a full
351 kernel build, and enabling this option causes the following
352 additional step to occur:
353 - Add the option -fno-inline-functions-called-once to gcc commands.
354 When inlining a function annotated with __init in a non-init
355 function, we would lose the section information and thus
356 the analysis would not catch the illegal reference.
357 This option tells gcc to inline less (but it does result in
360 config SECTION_MISMATCH_WARN_ONLY
361 bool "Make section mismatch errors non-fatal"
364 If you say N here, the build process will fail if there are any
365 section mismatch, instead of just throwing warnings.
370 # Select this config option from the architecture Kconfig, if it
371 # is preferred to always offer frame pointers as a config
372 # option on the architecture (regardless of KERNEL_DEBUG):
374 config ARCH_WANT_FRAME_POINTERS
378 bool "Compile the kernel with frame pointers"
379 depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
380 default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
382 If you say Y here the resulting kernel image will be slightly
383 larger and slower, but it gives very useful debugging information
384 in case of kernel bugs. (precise oopses/stacktraces/warnings)
386 config STACK_VALIDATION
387 bool "Compile-time stack metadata validation"
388 depends on HAVE_STACK_VALIDATION
391 Add compile-time checks to validate stack metadata, including frame
392 pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
393 that runtime stack traces are more reliable.
395 This is also a prerequisite for generation of ORC unwind data, which
396 is needed for CONFIG_UNWINDER_ORC.
398 For more information, see
399 tools/objtool/Documentation/stack-validation.txt.
401 config VMLINUX_VALIDATION
403 depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
406 config DEBUG_FORCE_WEAK_PER_CPU
407 bool "Force weak per-cpu definitions"
408 depends on DEBUG_KERNEL
410 s390 and alpha require percpu variables in modules to be
411 defined weak to work around addressing range issue which
412 puts the following two restrictions on percpu variable
415 1. percpu symbols must be unique whether static or not
416 2. percpu variables can't be defined inside a function
418 To ensure that generic code follows the above rules, this
419 option forces all percpu variables to be defined as weak.
421 endmenu # "Compiler options"
423 menu "Generic Kernel Debugging Instruments"
426 bool "Magic SysRq key"
429 If you say Y here, you will have some control over the system even
430 if the system crashes for example during kernel debugging (e.g., you
431 will be able to flush the buffer cache to disk, reboot the system
432 immediately or dump some status information). This is accomplished
433 by pressing various keys while holding SysRq (Alt+PrintScreen). It
434 also works on a serial console (on PC hardware at least), if you
435 send a BREAK and then within 5 seconds a command keypress. The
436 keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
437 Don't say Y unless you really know what this hack does.
439 config MAGIC_SYSRQ_DEFAULT_ENABLE
440 hex "Enable magic SysRq key functions by default"
441 depends on MAGIC_SYSRQ
444 Specifies which SysRq key functions are enabled by default.
445 This may be set to 1 or 0 to enable or disable them all, or
446 to a bitmask as described in Documentation/admin-guide/sysrq.rst.
448 config MAGIC_SYSRQ_SERIAL
449 bool "Enable magic SysRq key over serial"
450 depends on MAGIC_SYSRQ
453 Many embedded boards have a disconnected TTL level serial which can
454 generate some garbage that can lead to spurious false sysrq detects.
455 This option allows you to decide whether you want to enable the
458 config MAGIC_SYSRQ_SERIAL_SEQUENCE
459 string "Char sequence that enables magic SysRq over serial"
460 depends on MAGIC_SYSRQ_SERIAL
463 Specifies a sequence of characters that can follow BREAK to enable
464 SysRq on a serial console.
466 If unsure, leave an empty string and the option will not be enabled.
469 bool "Debug Filesystem"
471 debugfs is a virtual file system that kernel developers use to put
472 debugging files into. Enable this option to be able to read and
473 write to these files.
475 For detailed documentation on the debugfs API, see
476 Documentation/filesystems/.
480 source "lib/Kconfig.kgdb"
482 source "lib/Kconfig.ubsan"
487 bool "Kernel debugging"
489 Say Y here if you are developing drivers or trying to debug and
490 identify kernel problems.
493 bool "Miscellaneous debug code"
495 depends on DEBUG_KERNEL
497 Say Y here if you need to enable miscellaneous debug code that should
498 be under a more specific debug option but isn't.
501 menu "Memory Debugging"
503 source "mm/Kconfig.debug"
506 bool "Debug object operations"
507 depends on DEBUG_KERNEL
509 If you say Y here, additional code will be inserted into the
510 kernel to track the life time of various objects and validate
511 the operations on those objects.
513 config DEBUG_OBJECTS_SELFTEST
514 bool "Debug objects selftest"
515 depends on DEBUG_OBJECTS
517 This enables the selftest of the object debug code.
519 config DEBUG_OBJECTS_FREE
520 bool "Debug objects in freed memory"
521 depends on DEBUG_OBJECTS
523 This enables checks whether a k/v free operation frees an area
524 which contains an object which has not been deactivated
525 properly. This can make kmalloc/kfree-intensive workloads
528 config DEBUG_OBJECTS_TIMERS
529 bool "Debug timer objects"
530 depends on DEBUG_OBJECTS
532 If you say Y here, additional code will be inserted into the
533 timer routines to track the life time of timer objects and
534 validate the timer operations.
536 config DEBUG_OBJECTS_WORK
537 bool "Debug work objects"
538 depends on DEBUG_OBJECTS
540 If you say Y here, additional code will be inserted into the
541 work queue routines to track the life time of work objects and
542 validate the work operations.
544 config DEBUG_OBJECTS_RCU_HEAD
545 bool "Debug RCU callbacks objects"
546 depends on DEBUG_OBJECTS
548 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
550 config DEBUG_OBJECTS_PERCPU_COUNTER
551 bool "Debug percpu counter objects"
552 depends on DEBUG_OBJECTS
554 If you say Y here, additional code will be inserted into the
555 percpu counter routines to track the life time of percpu counter
556 objects and validate the percpu counter operations.
558 config DEBUG_OBJECTS_ENABLE_DEFAULT
559 int "debug_objects bootup default value (0-1)"
562 depends on DEBUG_OBJECTS
564 Debug objects boot parameter default value
567 bool "Debug slab memory allocations"
568 depends on DEBUG_KERNEL && SLAB
570 Say Y here to have the kernel do limited verification on memory
571 allocation as well as poisoning memory on free to catch use of freed
572 memory. This can make kmalloc/kfree-intensive workloads much slower.
575 bool "SLUB debugging on by default"
576 depends on SLUB && SLUB_DEBUG
579 Boot with debugging on by default. SLUB boots by default with
580 the runtime debug capabilities switched off. Enabling this is
581 equivalent to specifying the "slub_debug" parameter on boot.
582 There is no support for more fine grained debug control like
583 possible with slub_debug=xxx. SLUB debugging may be switched
584 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
589 bool "Enable SLUB performance statistics"
590 depends on SLUB && SYSFS
592 SLUB statistics are useful to debug SLUBs allocation behavior in
593 order find ways to optimize the allocator. This should never be
594 enabled for production use since keeping statistics slows down
595 the allocator by a few percentage points. The slabinfo command
596 supports the determination of the most active slabs to figure
597 out which slabs are relevant to a particular load.
598 Try running: slabinfo -DA
600 config HAVE_DEBUG_KMEMLEAK
603 config DEBUG_KMEMLEAK
604 bool "Kernel memory leak detector"
605 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
607 select STACKTRACE if STACKTRACE_SUPPORT
611 Say Y here if you want to enable the memory leak
612 detector. The memory allocation/freeing is traced in a way
613 similar to the Boehm's conservative garbage collector, the
614 difference being that the orphan objects are not freed but
615 only shown in /sys/kernel/debug/kmemleak. Enabling this
616 feature will introduce an overhead to memory
617 allocations. See Documentation/dev-tools/kmemleak.rst for more
620 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
621 of finding leaks due to the slab objects poisoning.
623 In order to access the kmemleak file, debugfs needs to be
624 mounted (usually at /sys/kernel/debug).
626 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
627 int "Kmemleak memory pool size"
628 depends on DEBUG_KMEMLEAK
632 Kmemleak must track all the memory allocations to avoid
633 reporting false positives. Since memory may be allocated or
634 freed before kmemleak is fully initialised, use a static pool
635 of metadata objects to track such callbacks. After kmemleak is
636 fully initialised, this memory pool acts as an emergency one
637 if slab allocations fail.
639 config DEBUG_KMEMLEAK_TEST
640 tristate "Simple test for the kernel memory leak detector"
641 depends on DEBUG_KMEMLEAK && m
643 This option enables a module that explicitly leaks memory.
647 config DEBUG_KMEMLEAK_DEFAULT_OFF
648 bool "Default kmemleak to off"
649 depends on DEBUG_KMEMLEAK
651 Say Y here to disable kmemleak by default. It can then be enabled
652 on the command line via kmemleak=on.
654 config DEBUG_KMEMLEAK_AUTO_SCAN
655 bool "Enable kmemleak auto scan thread on boot up"
657 depends on DEBUG_KMEMLEAK
659 Depending on the cpu, kmemleak scan may be cpu intensive and can
660 stall user tasks at times. This option enables/disables automatic
661 kmemleak scan at boot up.
663 Say N here to disable kmemleak auto scan thread to stop automatic
664 scanning. Disabling this option disables automatic reporting of
669 config DEBUG_STACK_USAGE
670 bool "Stack utilization instrumentation"
671 depends on DEBUG_KERNEL && !IA64
673 Enables the display of the minimum amount of free stack which each
674 task has ever had available in the sysrq-T and sysrq-P debug output.
676 This option will slow down process creation somewhat.
678 config SCHED_STACK_END_CHECK
679 bool "Detect stack corruption on calls to schedule()"
680 depends on DEBUG_KERNEL
683 This option checks for a stack overrun on calls to schedule().
684 If the stack end location is found to be over written always panic as
685 the content of the corrupted region can no longer be trusted.
686 This is to ensure no erroneous behaviour occurs which could result in
687 data corruption or a sporadic crash at a later stage once the region
688 is examined. The runtime overhead introduced is minimal.
690 config ARCH_HAS_DEBUG_VM_PGTABLE
693 An architecture should select this when it can successfully
694 build and run DEBUG_VM_PGTABLE.
698 depends on DEBUG_KERNEL
700 Enable this to turn on extended checks in the virtual-memory system
701 that may impact performance.
705 config DEBUG_VM_VMACACHE
706 bool "Debug VMA caching"
709 Enable this to turn on VMA caching debug information. Doing so
710 can cause significant overhead, so only enable it in non-production
716 bool "Debug VM red-black trees"
719 Enable VM red-black tree debugging information and extra validations.
723 config DEBUG_VM_PGFLAGS
724 bool "Debug page-flags operations"
727 Enables extra validation on page flags operations.
731 config DEBUG_VM_PGTABLE
732 bool "Debug arch page table for semantics compliance"
734 depends on ARCH_HAS_DEBUG_VM_PGTABLE
735 default y if DEBUG_VM
737 This option provides a debug method which can be used to test
738 architecture page table helper functions on various platforms in
739 verifying if they comply with expected generic MM semantics. This
740 will help architecture code in making sure that any changes or
741 new additions of these helpers still conform to expected
742 semantics of the generic MM. Platforms will have to opt in for
743 this through ARCH_HAS_DEBUG_VM_PGTABLE.
747 config ARCH_HAS_DEBUG_VIRTUAL
751 bool "Debug VM translations"
752 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
754 Enable some costly sanity checks in virtual to page code. This can
755 catch mistakes with virt_to_page() and friends.
759 config DEBUG_NOMMU_REGIONS
760 bool "Debug the global anon/private NOMMU mapping region tree"
761 depends on DEBUG_KERNEL && !MMU
763 This option causes the global tree of anonymous and private mapping
764 regions to be regularly checked for invalid topology.
766 config DEBUG_MEMORY_INIT
767 bool "Debug memory initialisation" if EXPERT
770 Enable this for additional checks during memory initialisation.
771 The sanity checks verify aspects of the VM such as the memory model
772 and other information provided by the architecture. Verbose
773 information will be printed at KERN_DEBUG loglevel depending
774 on the mminit_loglevel= command-line option.
778 config MEMORY_NOTIFIER_ERROR_INJECT
779 tristate "Memory hotplug notifier error injection module"
780 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
782 This option provides the ability to inject artificial errors to
783 memory hotplug notifier chain callbacks. It is controlled through
784 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
786 If the notifier call chain should be failed with some events
787 notified, write the error code to "actions/<notifier event>/error".
789 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
791 # cd /sys/kernel/debug/notifier-error-inject/memory
792 # echo -12 > actions/MEM_GOING_OFFLINE/error
793 # echo offline > /sys/devices/system/memory/memoryXXX/state
794 bash: echo: write error: Cannot allocate memory
796 To compile this code as a module, choose M here: the module will
797 be called memory-notifier-error-inject.
801 config DEBUG_PER_CPU_MAPS
802 bool "Debug access to per_cpu maps"
803 depends on DEBUG_KERNEL
806 Say Y to verify that the per_cpu map being accessed has
807 been set up. This adds a fair amount of code to kernel memory
808 and decreases performance.
813 bool "Highmem debugging"
814 depends on DEBUG_KERNEL && HIGHMEM
816 This option enables additional error checking for high memory
817 systems. Disable for production systems.
819 config HAVE_DEBUG_STACKOVERFLOW
822 config DEBUG_STACKOVERFLOW
823 bool "Check for stack overflows"
824 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
826 Say Y here if you want to check for overflows of kernel, IRQ
827 and exception stacks (if your architecture uses them). This
828 option will show detailed messages if free stack space drops
829 below a certain limit.
831 These kinds of bugs usually occur when call-chains in the
832 kernel get too deep, especially when interrupts are
835 Use this in cases where you see apparently random memory
836 corruption, especially if it appears in 'struct thread_info'
838 If in doubt, say "N".
840 source "lib/Kconfig.kasan"
842 endmenu # "Memory Debugging"
845 bool "Debug shared IRQ handlers"
846 depends on DEBUG_KERNEL
848 Enable this to generate a spurious interrupt as soon as a shared
849 interrupt handler is registered, and just before one is deregistered.
850 Drivers ought to be able to handle interrupts coming in at those
851 points; some don't and need to be caught.
853 menu "Debug Oops, Lockups and Hangs"
858 Say Y here to enable the kernel to panic when it oopses. This
859 has the same effect as setting oops=panic on the kernel command
862 This feature is useful to ensure that the kernel does not do
863 anything erroneous after an oops which could result in data
864 corruption or other issues.
868 config PANIC_ON_OOPS_VALUE
871 default 0 if !PANIC_ON_OOPS
872 default 1 if PANIC_ON_OOPS
878 Set the timeout value (in seconds) until a reboot occurs when the
879 the kernel panics. If n = 0, then we wait forever. A timeout
880 value n > 0 will wait n seconds before rebooting, while a timeout
881 value n < 0 will reboot immediately.
883 config LOCKUP_DETECTOR
886 config SOFTLOCKUP_DETECTOR
887 bool "Detect Soft Lockups"
888 depends on DEBUG_KERNEL && !S390
889 select LOCKUP_DETECTOR
891 Say Y here to enable the kernel to act as a watchdog to detect
894 Softlockups are bugs that cause the kernel to loop in kernel
895 mode for more than 20 seconds, without giving other tasks a
896 chance to run. The current stack trace is displayed upon
897 detection and the system will stay locked up.
899 config BOOTPARAM_SOFTLOCKUP_PANIC
900 bool "Panic (Reboot) On Soft Lockups"
901 depends on SOFTLOCKUP_DETECTOR
903 Say Y here to enable the kernel to panic on "soft lockups",
904 which are bugs that cause the kernel to loop in kernel
905 mode for more than 20 seconds (configurable using the watchdog_thresh
906 sysctl), without giving other tasks a chance to run.
908 The panic can be used in combination with panic_timeout,
909 to cause the system to reboot automatically after a
910 lockup has been detected. This feature is useful for
911 high-availability systems that have uptime guarantees and
912 where a lockup must be resolved ASAP.
916 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
918 depends on SOFTLOCKUP_DETECTOR
920 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
921 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
923 config HARDLOCKUP_DETECTOR_PERF
925 select SOFTLOCKUP_DETECTOR
928 # Enables a timestamp based low pass filter to compensate for perf based
929 # hard lockup detection which runs too fast due to turbo modes.
931 config HARDLOCKUP_CHECK_TIMESTAMP
935 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
936 # lockup detector rather than the perf based detector.
938 config HARDLOCKUP_DETECTOR
939 bool "Detect Hard Lockups"
940 depends on DEBUG_KERNEL && !S390
941 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
942 select LOCKUP_DETECTOR
943 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
944 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
946 Say Y here to enable the kernel to act as a watchdog to detect
949 Hardlockups are bugs that cause the CPU to loop in kernel mode
950 for more than 10 seconds, without letting other interrupts have a
951 chance to run. The current stack trace is displayed upon detection
952 and the system will stay locked up.
954 config BOOTPARAM_HARDLOCKUP_PANIC
955 bool "Panic (Reboot) On Hard Lockups"
956 depends on HARDLOCKUP_DETECTOR
958 Say Y here to enable the kernel to panic on "hard lockups",
959 which are bugs that cause the kernel to loop in kernel
960 mode with interrupts disabled for more than 10 seconds (configurable
961 using the watchdog_thresh sysctl).
965 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
967 depends on HARDLOCKUP_DETECTOR
969 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
970 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
972 config DETECT_HUNG_TASK
973 bool "Detect Hung Tasks"
974 depends on DEBUG_KERNEL
975 default SOFTLOCKUP_DETECTOR
977 Say Y here to enable the kernel to detect "hung tasks",
978 which are bugs that cause the task to be stuck in
979 uninterruptible "D" state indefinitely.
981 When a hung task is detected, the kernel will print the
982 current stack trace (which you should report), but the
983 task will stay in uninterruptible state. If lockdep is
984 enabled then all held locks will also be reported. This
985 feature has negligible overhead.
987 config DEFAULT_HUNG_TASK_TIMEOUT
988 int "Default timeout for hung task detection (in seconds)"
989 depends on DETECT_HUNG_TASK
992 This option controls the default timeout (in seconds) used
993 to determine when a task has become non-responsive and should
996 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
997 sysctl or by writing a value to
998 /proc/sys/kernel/hung_task_timeout_secs.
1000 A timeout of 0 disables the check. The default is two minutes.
1001 Keeping the default should be fine in most cases.
1003 config BOOTPARAM_HUNG_TASK_PANIC
1004 bool "Panic (Reboot) On Hung Tasks"
1005 depends on DETECT_HUNG_TASK
1007 Say Y here to enable the kernel to panic on "hung tasks",
1008 which are bugs that cause the kernel to leave a task stuck
1009 in uninterruptible "D" state.
1011 The panic can be used in combination with panic_timeout,
1012 to cause the system to reboot automatically after a
1013 hung task has been detected. This feature is useful for
1014 high-availability systems that have uptime guarantees and
1015 where a hung tasks must be resolved ASAP.
1019 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1021 depends on DETECT_HUNG_TASK
1023 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1024 default 1 if BOOTPARAM_HUNG_TASK_PANIC
1027 bool "Detect Workqueue Stalls"
1028 depends on DEBUG_KERNEL
1030 Say Y here to enable stall detection on workqueues. If a
1031 worker pool doesn't make forward progress on a pending work
1032 item for over a given amount of time, 30s by default, a
1033 warning message is printed along with dump of workqueue
1034 state. This can be configured through kernel parameter
1035 "workqueue.watchdog_thresh" and its sysfs counterpart.
1038 tristate "Test module to generate lockups"
1040 This builds the "test_lockup" module that helps to make sure
1041 that watchdogs and lockup detectors are working properly.
1043 Depending on module parameters it could emulate soft or hard
1044 lockup, "hung task", or locking arbitrary lock for a long time.
1045 Also it could generate series of lockups with cooling-down periods.
1049 endmenu # "Debug lockups and hangs"
1051 menu "Scheduler Debugging"
1054 bool "Collect scheduler debugging info"
1055 depends on DEBUG_KERNEL && PROC_FS
1058 If you say Y here, the /proc/sched_debug file will be provided
1059 that can help debug the scheduler. The runtime overhead of this
1067 bool "Collect scheduler statistics"
1068 depends on DEBUG_KERNEL && PROC_FS
1071 If you say Y here, additional code will be inserted into the
1072 scheduler and related routines to collect statistics about
1073 scheduler behavior and provide them in /proc/schedstat. These
1074 stats may be useful for both tuning and debugging the scheduler
1075 If you aren't debugging the scheduler or trying to tune a specific
1076 application, you can say N to avoid the very slight overhead
1081 config DEBUG_TIMEKEEPING
1082 bool "Enable extra timekeeping sanity checking"
1084 This option will enable additional timekeeping sanity checks
1085 which may be helpful when diagnosing issues where timekeeping
1086 problems are suspected.
1088 This may include checks in the timekeeping hotpaths, so this
1089 option may have a (very small) performance impact to some
1094 config DEBUG_PREEMPT
1095 bool "Debug preemptible kernel"
1096 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1099 If you say Y here then the kernel will use a debug variant of the
1100 commonly used smp_processor_id() function and will print warnings
1101 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1102 will detect preemption count underflows.
1104 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1106 config LOCK_DEBUGGING_SUPPORT
1108 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1111 config PROVE_LOCKING
1112 bool "Lock debugging: prove locking correctness"
1113 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1115 select DEBUG_SPINLOCK
1116 select DEBUG_MUTEXES
1117 select DEBUG_RT_MUTEXES if RT_MUTEXES
1119 select DEBUG_WW_MUTEX_SLOWPATH
1120 select DEBUG_LOCK_ALLOC
1121 select TRACE_IRQFLAGS
1124 This feature enables the kernel to prove that all locking
1125 that occurs in the kernel runtime is mathematically
1126 correct: that under no circumstance could an arbitrary (and
1127 not yet triggered) combination of observed locking
1128 sequences (on an arbitrary number of CPUs, running an
1129 arbitrary number of tasks and interrupt contexts) cause a
1132 In short, this feature enables the kernel to report locking
1133 related deadlocks before they actually occur.
1135 The proof does not depend on how hard and complex a
1136 deadlock scenario would be to trigger: how many
1137 participant CPUs, tasks and irq-contexts would be needed
1138 for it to trigger. The proof also does not depend on
1139 timing: if a race and a resulting deadlock is possible
1140 theoretically (no matter how unlikely the race scenario
1141 is), it will be proven so and will immediately be
1142 reported by the kernel (once the event is observed that
1143 makes the deadlock theoretically possible).
1145 If a deadlock is impossible (i.e. the locking rules, as
1146 observed by the kernel, are mathematically correct), the
1147 kernel reports nothing.
1149 NOTE: this feature can also be enabled for rwlocks, mutexes
1150 and rwsems - in which case all dependencies between these
1151 different locking variants are observed and mapped too, and
1152 the proof of observed correctness is also maintained for an
1153 arbitrary combination of these separate locking variants.
1155 For more details, see Documentation/locking/lockdep-design.rst.
1157 config PROVE_RAW_LOCK_NESTING
1158 bool "Enable raw_spinlock - spinlock nesting checks"
1159 depends on PROVE_LOCKING
1162 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1163 that the lock nesting rules for PREEMPT_RT enabled kernels are
1166 NOTE: There are known nesting problems. So if you enable this
1167 option expect lockdep splats until these problems have been fully
1168 addressed which is work in progress. This config switch allows to
1169 identify and analyze these problems. It will be removed and the
1170 check permanentely enabled once the main issues have been fixed.
1172 If unsure, select N.
1175 bool "Lock usage statistics"
1176 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1178 select DEBUG_SPINLOCK
1179 select DEBUG_MUTEXES
1180 select DEBUG_RT_MUTEXES if RT_MUTEXES
1181 select DEBUG_LOCK_ALLOC
1184 This feature enables tracking lock contention points
1186 For more details, see Documentation/locking/lockstat.rst
1188 This also enables lock events required by "perf lock",
1190 If you want to use "perf lock", you also need to turn on
1191 CONFIG_EVENT_TRACING.
1193 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1194 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1196 config DEBUG_RT_MUTEXES
1197 bool "RT Mutex debugging, deadlock detection"
1198 depends on DEBUG_KERNEL && RT_MUTEXES
1200 This allows rt mutex semantics violations and rt mutex related
1201 deadlocks (lockups) to be detected and reported automatically.
1203 config DEBUG_SPINLOCK
1204 bool "Spinlock and rw-lock debugging: basic checks"
1205 depends on DEBUG_KERNEL
1206 select UNINLINE_SPIN_UNLOCK
1208 Say Y here and build SMP to catch missing spinlock initialization
1209 and certain other kinds of spinlock errors commonly made. This is
1210 best used in conjunction with the NMI watchdog so that spinlock
1211 deadlocks are also debuggable.
1213 config DEBUG_MUTEXES
1214 bool "Mutex debugging: basic checks"
1215 depends on DEBUG_KERNEL
1217 This feature allows mutex semantics violations to be detected and
1220 config DEBUG_WW_MUTEX_SLOWPATH
1221 bool "Wait/wound mutex debugging: Slowpath testing"
1222 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1223 select DEBUG_LOCK_ALLOC
1224 select DEBUG_SPINLOCK
1225 select DEBUG_MUTEXES
1227 This feature enables slowpath testing for w/w mutex users by
1228 injecting additional -EDEADLK wound/backoff cases. Together with
1229 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1230 will test all possible w/w mutex interface abuse with the
1231 exception of simply not acquiring all the required locks.
1232 Note that this feature can introduce significant overhead, so
1233 it really should not be enabled in a production or distro kernel,
1234 even a debug kernel. If you are a driver writer, enable it. If
1235 you are a distro, do not.
1238 bool "RW Semaphore debugging: basic checks"
1239 depends on DEBUG_KERNEL
1241 This debugging feature allows mismatched rw semaphore locks
1242 and unlocks to be detected and reported.
1244 config DEBUG_LOCK_ALLOC
1245 bool "Lock debugging: detect incorrect freeing of live locks"
1246 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1247 select DEBUG_SPINLOCK
1248 select DEBUG_MUTEXES
1249 select DEBUG_RT_MUTEXES if RT_MUTEXES
1252 This feature will check whether any held lock (spinlock, rwlock,
1253 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1254 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1255 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1256 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1257 held during task exit.
1261 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1263 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1267 config LOCKDEP_SMALL
1270 config DEBUG_LOCKDEP
1271 bool "Lock dependency engine debugging"
1272 depends on DEBUG_KERNEL && LOCKDEP
1274 If you say Y here, the lock dependency engine will do
1275 additional runtime checks to debug itself, at the price
1276 of more runtime overhead.
1278 config DEBUG_ATOMIC_SLEEP
1279 bool "Sleep inside atomic section checking"
1280 select PREEMPT_COUNT
1281 depends on DEBUG_KERNEL
1282 depends on !ARCH_NO_PREEMPT
1284 If you say Y here, various routines which may sleep will become very
1285 noisy if they are called inside atomic sections: when a spinlock is
1286 held, inside an rcu read side critical section, inside preempt disabled
1287 sections, inside an interrupt, etc...
1289 config DEBUG_LOCKING_API_SELFTESTS
1290 bool "Locking API boot-time self-tests"
1291 depends on DEBUG_KERNEL
1293 Say Y here if you want the kernel to run a short self-test during
1294 bootup. The self-test checks whether common types of locking bugs
1295 are detected by debugging mechanisms or not. (if you disable
1296 lock debugging then those bugs wont be detected of course.)
1297 The following locking APIs are covered: spinlocks, rwlocks,
1300 config LOCK_TORTURE_TEST
1301 tristate "torture tests for locking"
1302 depends on DEBUG_KERNEL
1305 This option provides a kernel module that runs torture tests
1306 on kernel locking primitives. The kernel module may be built
1307 after the fact on the running kernel to be tested, if desired.
1309 Say Y here if you want kernel locking-primitive torture tests
1310 to be built into the kernel.
1311 Say M if you want these torture tests to build as a module.
1312 Say N if you are unsure.
1314 config WW_MUTEX_SELFTEST
1315 tristate "Wait/wound mutex selftests"
1317 This option provides a kernel module that runs tests on the
1318 on the struct ww_mutex locking API.
1320 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1321 with this test harness.
1323 Say M if you want these self tests to build as a module.
1324 Say N if you are unsure.
1326 endmenu # lock debugging
1328 config TRACE_IRQFLAGS
1331 Enables hooks to interrupt enabling and disabling for
1332 either tracing or lock debugging.
1335 bool "Stack backtrace support"
1336 depends on STACKTRACE_SUPPORT
1338 This option causes the kernel to create a /proc/pid/stack for
1339 every process, showing its current stack trace.
1340 It is also used by various kernel debugging features that require
1341 stack trace generation.
1343 config WARN_ALL_UNSEEDED_RANDOM
1344 bool "Warn for all uses of unseeded randomness"
1347 Some parts of the kernel contain bugs relating to their use of
1348 cryptographically secure random numbers before it's actually possible
1349 to generate those numbers securely. This setting ensures that these
1350 flaws don't go unnoticed, by enabling a message, should this ever
1351 occur. This will allow people with obscure setups to know when things
1352 are going wrong, so that they might contact developers about fixing
1355 Unfortunately, on some models of some architectures getting
1356 a fully seeded CRNG is extremely difficult, and so this can
1357 result in dmesg getting spammed for a surprisingly long
1358 time. This is really bad from a security perspective, and
1359 so architecture maintainers really need to do what they can
1360 to get the CRNG seeded sooner after the system is booted.
1361 However, since users cannot do anything actionable to
1362 address this, by default the kernel will issue only a single
1363 warning for the first use of unseeded randomness.
1365 Say Y here if you want to receive warnings for all uses of
1366 unseeded randomness. This will be of use primarily for
1367 those developers interested in improving the security of
1368 Linux kernels running on their architecture (or
1371 config DEBUG_KOBJECT
1372 bool "kobject debugging"
1373 depends on DEBUG_KERNEL
1375 If you say Y here, some extra kobject debugging messages will be sent
1378 config DEBUG_KOBJECT_RELEASE
1379 bool "kobject release debugging"
1380 depends on DEBUG_OBJECTS_TIMERS
1382 kobjects are reference counted objects. This means that their
1383 last reference count put is not predictable, and the kobject can
1384 live on past the point at which a driver decides to drop it's
1385 initial reference to the kobject gained on allocation. An
1386 example of this would be a struct device which has just been
1389 However, some buggy drivers assume that after such an operation,
1390 the memory backing the kobject can be immediately freed. This
1391 goes completely against the principles of a refcounted object.
1393 If you say Y here, the kernel will delay the release of kobjects
1394 on the last reference count to improve the visibility of this
1395 kind of kobject release bug.
1397 config HAVE_DEBUG_BUGVERBOSE
1400 menu "Debug kernel data structures"
1403 bool "Debug linked list manipulation"
1404 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1406 Enable this to turn on extended checks in the linked-list
1412 bool "Debug priority linked list manipulation"
1413 depends on DEBUG_KERNEL
1415 Enable this to turn on extended checks in the priority-ordered
1416 linked-list (plist) walking routines. This checks the entire
1417 list multiple times during each manipulation.
1422 bool "Debug SG table operations"
1423 depends on DEBUG_KERNEL
1425 Enable this to turn on checks on scatter-gather tables. This can
1426 help find problems with drivers that do not properly initialize
1431 config DEBUG_NOTIFIERS
1432 bool "Debug notifier call chains"
1433 depends on DEBUG_KERNEL
1435 Enable this to turn on sanity checking for notifier call chains.
1436 This is most useful for kernel developers to make sure that
1437 modules properly unregister themselves from notifier chains.
1438 This is a relatively cheap check but if you care about maximum
1441 config BUG_ON_DATA_CORRUPTION
1442 bool "Trigger a BUG when data corruption is detected"
1445 Select this option if the kernel should BUG when it encounters
1446 data corruption in kernel memory structures when they get checked
1453 config DEBUG_CREDENTIALS
1454 bool "Debug credential management"
1455 depends on DEBUG_KERNEL
1457 Enable this to turn on some debug checking for credential
1458 management. The additional code keeps track of the number of
1459 pointers from task_structs to any given cred struct, and checks to
1460 see that this number never exceeds the usage count of the cred
1463 Furthermore, if SELinux is enabled, this also checks that the
1464 security pointer in the cred struct is never seen to be invalid.
1468 source "kernel/rcu/Kconfig.debug"
1470 config DEBUG_WQ_FORCE_RR_CPU
1471 bool "Force round-robin CPU selection for unbound work items"
1472 depends on DEBUG_KERNEL
1475 Workqueue used to implicitly guarantee that work items queued
1476 without explicit CPU specified are put on the local CPU. This
1477 guarantee is no longer true and while local CPU is still
1478 preferred work items may be put on foreign CPUs. Kernel
1479 parameter "workqueue.debug_force_rr_cpu" is added to force
1480 round-robin CPU selection to flush out usages which depend on the
1481 now broken guarantee. This config option enables the debug
1482 feature by default. When enabled, memory and cache locality will
1485 config DEBUG_BLOCK_EXT_DEVT
1486 bool "Force extended block device numbers and spread them"
1487 depends on DEBUG_KERNEL
1491 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1492 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1493 YOU ARE DOING. Distros, please enable this and fix whatever
1496 Conventionally, block device numbers are allocated from
1497 predetermined contiguous area. However, extended block area
1498 may introduce non-contiguous block device numbers. This
1499 option forces most block device numbers to be allocated from
1500 the extended space and spreads them to discover kernel or
1501 userland code paths which assume predetermined contiguous
1502 device number allocation.
1504 Note that turning on this debug option shuffles all the
1505 device numbers for all IDE and SCSI devices including libata
1506 ones, so root partition specified using device number
1507 directly (via rdev or root=MAJ:MIN) won't work anymore.
1508 Textual device names (root=/dev/sdXn) will continue to work.
1510 Say N if you are unsure.
1512 config CPU_HOTPLUG_STATE_CONTROL
1513 bool "Enable CPU hotplug state control"
1514 depends on DEBUG_KERNEL
1515 depends on HOTPLUG_CPU
1518 Allows to write steps between "offline" and "online" to the CPUs
1519 sysfs target file so states can be stepped granular. This is a debug
1520 option for now as the hotplug machinery cannot be stopped and
1521 restarted at arbitrary points yet.
1523 Say N if your are unsure.
1526 bool "Latency measuring infrastructure"
1527 depends on DEBUG_KERNEL
1528 depends on STACKTRACE_SUPPORT
1530 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1537 Enable this option if you want to use the LatencyTOP tool
1538 to find out which userspace is blocking on what kernel operations.
1540 source "kernel/trace/Kconfig"
1542 config PROVIDE_OHCI1394_DMA_INIT
1543 bool "Remote debugging over FireWire early on boot"
1544 depends on PCI && X86
1546 If you want to debug problems which hang or crash the kernel early
1547 on boot and the crashing machine has a FireWire port, you can use
1548 this feature to remotely access the memory of the crashed machine
1549 over FireWire. This employs remote DMA as part of the OHCI1394
1550 specification which is now the standard for FireWire controllers.
1552 With remote DMA, you can monitor the printk buffer remotely using
1553 firescope and access all memory below 4GB using fireproxy from gdb.
1554 Even controlling a kernel debugger is possible using remote DMA.
1558 If ohci1394_dma=early is used as boot parameter, it will initialize
1559 all OHCI1394 controllers which are found in the PCI config space.
1561 As all changes to the FireWire bus such as enabling and disabling
1562 devices cause a bus reset and thereby disable remote DMA for all
1563 devices, be sure to have the cable plugged and FireWire enabled on
1564 the debugging host before booting the debug target for debugging.
1566 This code (~1k) is freed after boot. By then, the firewire stack
1567 in charge of the OHCI-1394 controllers should be used instead.
1569 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1571 source "samples/Kconfig"
1573 source "lib/Kconfig.kcsan"
1575 config ARCH_HAS_DEVMEM_IS_ALLOWED
1578 config STRICT_DEVMEM
1579 bool "Filter access to /dev/mem"
1580 depends on MMU && DEVMEM
1581 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1582 default y if PPC || X86 || ARM64
1584 If this option is disabled, you allow userspace (root) access to all
1585 of memory, including kernel and userspace memory. Accidental
1586 access to this is obviously disastrous, but specific access can
1587 be used by people debugging the kernel. Note that with PAT support
1588 enabled, even in this case there are restrictions on /dev/mem
1589 use due to the cache aliasing requirements.
1591 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1592 file only allows userspace access to PCI space and the BIOS code and
1593 data regions. This is sufficient for dosemu and X and all common
1598 config IO_STRICT_DEVMEM
1599 bool "Filter I/O access to /dev/mem"
1600 depends on STRICT_DEVMEM
1602 If this option is disabled, you allow userspace (root) access to all
1603 io-memory regardless of whether a driver is actively using that
1604 range. Accidental access to this is obviously disastrous, but
1605 specific access can be used by people debugging kernel drivers.
1607 If this option is switched on, the /dev/mem file only allows
1608 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1609 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1610 if the driver using a given range cannot be disabled.
1614 menu "$(SRCARCH) Debugging"
1616 source "arch/$(SRCARCH)/Kconfig.debug"
1620 menu "Kernel Testing and Coverage"
1622 source "lib/kunit/Kconfig"
1624 config NOTIFIER_ERROR_INJECTION
1625 tristate "Notifier error injection"
1626 depends on DEBUG_KERNEL
1629 This option provides the ability to inject artificial errors to
1630 specified notifier chain callbacks. It is useful to test the error
1631 handling of notifier call chain failures.
1635 config PM_NOTIFIER_ERROR_INJECT
1636 tristate "PM notifier error injection module"
1637 depends on PM && NOTIFIER_ERROR_INJECTION
1638 default m if PM_DEBUG
1640 This option provides the ability to inject artificial errors to
1641 PM notifier chain callbacks. It is controlled through debugfs
1642 interface /sys/kernel/debug/notifier-error-inject/pm
1644 If the notifier call chain should be failed with some events
1645 notified, write the error code to "actions/<notifier event>/error".
1647 Example: Inject PM suspend error (-12 = -ENOMEM)
1649 # cd /sys/kernel/debug/notifier-error-inject/pm/
1650 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1651 # echo mem > /sys/power/state
1652 bash: echo: write error: Cannot allocate memory
1654 To compile this code as a module, choose M here: the module will
1655 be called pm-notifier-error-inject.
1659 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1660 tristate "OF reconfig notifier error injection module"
1661 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1663 This option provides the ability to inject artificial errors to
1664 OF reconfig notifier chain callbacks. It is controlled
1665 through debugfs interface under
1666 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1668 If the notifier call chain should be failed with some events
1669 notified, write the error code to "actions/<notifier event>/error".
1671 To compile this code as a module, choose M here: the module will
1672 be called of-reconfig-notifier-error-inject.
1676 config NETDEV_NOTIFIER_ERROR_INJECT
1677 tristate "Netdev notifier error injection module"
1678 depends on NET && NOTIFIER_ERROR_INJECTION
1680 This option provides the ability to inject artificial errors to
1681 netdevice notifier chain callbacks. It is controlled through debugfs
1682 interface /sys/kernel/debug/notifier-error-inject/netdev
1684 If the notifier call chain should be failed with some events
1685 notified, write the error code to "actions/<notifier event>/error".
1687 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1689 # cd /sys/kernel/debug/notifier-error-inject/netdev
1690 # echo -22 > actions/NETDEV_CHANGEMTU/error
1691 # ip link set eth0 mtu 1024
1692 RTNETLINK answers: Invalid argument
1694 To compile this code as a module, choose M here: the module will
1695 be called netdev-notifier-error-inject.
1699 config FUNCTION_ERROR_INJECTION
1701 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1703 config FAULT_INJECTION
1704 bool "Fault-injection framework"
1705 depends on DEBUG_KERNEL
1707 Provide fault-injection framework.
1708 For more details, see Documentation/fault-injection/.
1711 bool "Fault-injection capability for kmalloc"
1712 depends on FAULT_INJECTION
1713 depends on SLAB || SLUB
1715 Provide fault-injection capability for kmalloc.
1717 config FAIL_PAGE_ALLOC
1718 bool "Fault-injection capability for alloc_pages()"
1719 depends on FAULT_INJECTION
1721 Provide fault-injection capability for alloc_pages().
1723 config FAIL_MAKE_REQUEST
1724 bool "Fault-injection capability for disk IO"
1725 depends on FAULT_INJECTION && BLOCK
1727 Provide fault-injection capability for disk IO.
1729 config FAIL_IO_TIMEOUT
1730 bool "Fault-injection capability for faking disk interrupts"
1731 depends on FAULT_INJECTION && BLOCK
1733 Provide fault-injection capability on end IO handling. This
1734 will make the block layer "forget" an interrupt as configured,
1735 thus exercising the error handling.
1737 Only works with drivers that use the generic timeout handling,
1738 for others it wont do anything.
1741 bool "Fault-injection capability for futexes"
1743 depends on FAULT_INJECTION && FUTEX
1745 Provide fault-injection capability for futexes.
1747 config FAULT_INJECTION_DEBUG_FS
1748 bool "Debugfs entries for fault-injection capabilities"
1749 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1751 Enable configuration of fault-injection capabilities via debugfs.
1753 config FAIL_FUNCTION
1754 bool "Fault-injection capability for functions"
1755 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1757 Provide function-based fault-injection capability.
1758 This will allow you to override a specific function with a return
1759 with given return value. As a result, function caller will see
1760 an error value and have to handle it. This is useful to test the
1761 error handling in various subsystems.
1763 config FAIL_MMC_REQUEST
1764 bool "Fault-injection capability for MMC IO"
1765 depends on FAULT_INJECTION_DEBUG_FS && MMC
1767 Provide fault-injection capability for MMC IO.
1768 This will make the mmc core return data errors. This is
1769 useful to test the error handling in the mmc block device
1770 and to test how the mmc host driver handles retries from
1773 config FAULT_INJECTION_STACKTRACE_FILTER
1774 bool "stacktrace filter for fault-injection capabilities"
1775 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1778 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1780 Provide stacktrace filter for fault-injection capabilities
1782 config ARCH_HAS_KCOV
1785 An architecture should select this when it can successfully
1786 build and run with CONFIG_KCOV. This typically requires
1787 disabling instrumentation for some early boot code.
1789 config CC_HAS_SANCOV_TRACE_PC
1790 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1794 bool "Code coverage for fuzzing"
1795 depends on ARCH_HAS_KCOV
1796 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1798 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1800 KCOV exposes kernel code coverage information in a form suitable
1801 for coverage-guided fuzzing (randomized testing).
1803 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1804 different machines and across reboots. If you need stable PC values,
1805 disable RANDOMIZE_BASE.
1807 For more details, see Documentation/dev-tools/kcov.rst.
1809 config KCOV_ENABLE_COMPARISONS
1810 bool "Enable comparison operands collection by KCOV"
1812 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1814 KCOV also exposes operands of every comparison in the instrumented
1815 code along with operand sizes and PCs of the comparison instructions.
1816 These operands can be used by fuzzing engines to improve the quality
1817 of fuzzing coverage.
1819 config KCOV_INSTRUMENT_ALL
1820 bool "Instrument all code by default"
1824 If you are doing generic system call fuzzing (like e.g. syzkaller),
1825 then you will want to instrument the whole kernel and you should
1826 say y here. If you are doing more targeted fuzzing (like e.g.
1827 filesystem fuzzing with AFL) then you will want to enable coverage
1828 for more specific subsets of files, and should say n here.
1830 config KCOV_IRQ_AREA_SIZE
1831 hex "Size of interrupt coverage collection area in words"
1835 KCOV uses preallocated per-cpu areas to collect coverage from
1836 soft interrupts. This specifies the size of those areas in the
1837 number of unsigned long words.
1839 menuconfig RUNTIME_TESTING_MENU
1840 bool "Runtime Testing"
1843 if RUNTIME_TESTING_MENU
1846 tristate "Linux Kernel Dump Test Tool Module"
1849 This module enables testing of the different dumping mechanisms by
1850 inducing system failures at predefined crash points.
1851 If you don't need it: say N
1852 Choose M here to compile this code as a module. The module will be
1855 Documentation on how to use the module can be found in
1856 Documentation/fault-injection/provoke-crashes.rst
1858 config TEST_LIST_SORT
1859 tristate "Linked list sorting test"
1860 depends on DEBUG_KERNEL || m
1862 Enable this to turn on 'list_sort()' function test. This test is
1863 executed only once during system boot (so affects only boot time),
1864 or at module load time.
1868 config TEST_MIN_HEAP
1869 tristate "Min heap test"
1870 depends on DEBUG_KERNEL || m
1872 Enable this to turn on min heap function tests. This test is
1873 executed only once during system boot (so affects only boot time),
1874 or at module load time.
1879 tristate "Array-based sort test"
1880 depends on DEBUG_KERNEL || m
1882 This option enables the self-test function of 'sort()' at boot,
1883 or at module load time.
1887 config KPROBES_SANITY_TEST
1888 bool "Kprobes sanity tests"
1889 depends on DEBUG_KERNEL
1892 This option provides for testing basic kprobes functionality on
1893 boot. Samples of kprobe and kretprobe are inserted and
1894 verified for functionality.
1896 Say N if you are unsure.
1898 config BACKTRACE_SELF_TEST
1899 tristate "Self test for the backtrace code"
1900 depends on DEBUG_KERNEL
1902 This option provides a kernel module that can be used to test
1903 the kernel stack backtrace code. This option is not useful
1904 for distributions or general kernels, but only for kernel
1905 developers working on architecture code.
1907 Note that if you want to also test saved backtraces, you will
1908 have to enable STACKTRACE as well.
1910 Say N if you are unsure.
1913 tristate "Red-Black tree test"
1914 depends on DEBUG_KERNEL
1916 A benchmark measuring the performance of the rbtree library.
1917 Also includes rbtree invariant checks.
1919 config REED_SOLOMON_TEST
1920 tristate "Reed-Solomon library test"
1921 depends on DEBUG_KERNEL || m
1923 select REED_SOLOMON_ENC16
1924 select REED_SOLOMON_DEC16
1926 This option enables the self-test function of rslib at boot,
1927 or at module load time.
1931 config INTERVAL_TREE_TEST
1932 tristate "Interval tree test"
1933 depends on DEBUG_KERNEL
1934 select INTERVAL_TREE
1936 A benchmark measuring the performance of the interval tree library
1939 tristate "Per cpu operations test"
1940 depends on m && DEBUG_KERNEL
1942 Enable this option to build test module which validates per-cpu
1947 config ATOMIC64_SELFTEST
1948 tristate "Perform an atomic64_t self-test"
1950 Enable this option to test the atomic64_t functions at boot or
1951 at module load time.
1955 config ASYNC_RAID6_TEST
1956 tristate "Self test for hardware accelerated raid6 recovery"
1957 depends on ASYNC_RAID6_RECOV
1960 This is a one-shot self test that permutes through the
1961 recovery of all the possible two disk failure scenarios for a
1962 N-disk array. Recovery is performed with the asynchronous
1963 raid6 recovery routines, and will optionally use an offload
1964 engine if one is available.
1969 tristate "Test functions located in the hexdump module at runtime"
1971 config TEST_STRING_HELPERS
1972 tristate "Test functions located in the string_helpers module at runtime"
1975 tristate "Test strscpy*() family of functions at runtime"
1978 tristate "Test kstrto*() family of functions at runtime"
1981 tristate "Test printf() family of functions at runtime"
1984 tristate "Test bitmap_*() family of functions at runtime"
1986 Enable this option to test the bitmap functions at boot.
1990 config TEST_BITFIELD
1991 tristate "Test bitfield functions at runtime"
1993 Enable this option to test the bitfield functions at boot.
1998 tristate "Test functions located in the uuid module at runtime"
2001 tristate "Test the XArray code at runtime"
2003 config TEST_OVERFLOW
2004 tristate "Test check_*_overflow() functions at runtime"
2006 config TEST_RHASHTABLE
2007 tristate "Perform selftest on resizable hash table"
2009 Enable this option to test the rhashtable functions at boot.
2014 tristate "Perform selftest on hash functions"
2016 Enable this option to test the kernel's integer (<linux/hash.h>),
2017 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2018 hash functions on boot (or module load).
2020 This is intended to help people writing architecture-specific
2021 optimized versions. If unsure, say N.
2024 tristate "Perform selftest on IDA functions"
2027 tristate "Perform selftest on priority array manager"
2030 Enable this option to test priority array manager on boot
2035 config TEST_IRQ_TIMINGS
2036 bool "IRQ timings selftest"
2037 depends on IRQ_TIMINGS
2039 Enable this option to test the irq timings code on boot.
2044 tristate "Test module loading with 'hello world' module"
2047 This builds the "test_module" module that emits "Hello, world"
2048 on printk when loaded. It is designed to be used for basic
2049 evaluation of the module loading subsystem (for example when
2050 validating module verification). It lacks any extra dependencies,
2051 and will not normally be loaded by the system unless explicitly
2057 tristate "Test module for compilation of bitops operations"
2060 This builds the "test_bitops" module that is much like the
2061 TEST_LKM module except that it does a basic exercise of the
2062 set/clear_bit macros and get_count_order/long to make sure there are
2063 no compiler warnings from C=1 sparse checker or -Wextra
2064 compilations. It has no dependencies and doesn't run or load unless
2065 explicitly requested by name. for example: modprobe test_bitops.
2070 tristate "Test module for stress/performance analysis of vmalloc allocator"
2075 This builds the "test_vmalloc" module that should be used for
2076 stress and performance analysis. So, any new change for vmalloc
2077 subsystem can be evaluated from performance and stability point
2082 config TEST_USER_COPY
2083 tristate "Test user/kernel boundary protections"
2086 This builds the "test_user_copy" module that runs sanity checks
2087 on the copy_to/from_user infrastructure, making sure basic
2088 user/kernel boundary testing is working. If it fails to load,
2089 a regression has been detected in the user/kernel memory boundary
2095 tristate "Test BPF filter functionality"
2098 This builds the "test_bpf" module that runs various test vectors
2099 against the BPF interpreter or BPF JIT compiler depending on the
2100 current setting. This is in particular useful for BPF JIT compiler
2101 development, but also to run regression tests against changes in
2102 the interpreter code. It also enables test stubs for eBPF maps and
2103 verifier used by user space verifier testsuite.
2107 config TEST_BLACKHOLE_DEV
2108 tristate "Test blackhole netdev functionality"
2111 This builds the "test_blackhole_dev" module that validates the
2112 data path through this blackhole netdev.
2116 config FIND_BIT_BENCHMARK
2117 tristate "Test find_bit functions"
2119 This builds the "test_find_bit" module that measure find_*_bit()
2120 functions performance.
2124 config TEST_FIRMWARE
2125 tristate "Test firmware loading via userspace interface"
2126 depends on FW_LOADER
2128 This builds the "test_firmware" module that creates a userspace
2129 interface for testing firmware loading. This can be used to
2130 control the triggering of firmware loading without needing an
2131 actual firmware-using device. The contents can be rechecked by
2137 tristate "sysctl test driver"
2138 depends on PROC_SYSCTL
2140 This builds the "test_sysctl" module. This driver enables to test the
2141 proc sysctl interfaces available to drivers safely without affecting
2142 production knobs which might alter system functionality.
2146 config SYSCTL_KUNIT_TEST
2147 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2149 default KUNIT_ALL_TESTS
2151 This builds the proc sysctl unit test, which runs on boot.
2152 Tests the API contract and implementation correctness of sysctl.
2153 For more information on KUnit and unit tests in general please refer
2154 to the KUnit documentation in Documentation/dev-tools/kunit/.
2158 config LIST_KUNIT_TEST
2159 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2161 default KUNIT_ALL_TESTS
2163 This builds the linked list KUnit test suite.
2164 It tests that the API and basic functionality of the list_head type
2165 and associated macros.
2167 KUnit tests run during boot and output the results to the debug log
2168 in TAP format (http://testanything.org/). Only useful for kernel devs
2169 running the KUnit test harness, and not intended for inclusion into a
2172 For more information on KUnit and unit tests in general please refer
2173 to the KUnit documentation in Documentation/dev-tools/kunit/.
2177 config LINEAR_RANGES_TEST
2178 tristate "KUnit test for linear_ranges"
2180 select LINEAR_RANGES
2182 This builds the linear_ranges unit test, which runs on boot.
2183 Tests the linear_ranges logic correctness.
2184 For more information on KUnit and unit tests in general please refer
2185 to the KUnit documentation in Documentation/dev-tools/kunit/.
2190 tristate "udelay test driver"
2192 This builds the "udelay_test" module that helps to make sure
2193 that udelay() is working properly.
2197 config TEST_STATIC_KEYS
2198 tristate "Test static keys"
2201 Test the static key interfaces.
2206 tristate "kmod stress tester"
2208 depends on NETDEVICES && NET_CORE && INET # for TUN
2215 Test the kernel's module loading mechanism: kmod. kmod implements
2216 support to load modules using the Linux kernel's usermode helper.
2217 This test provides a series of tests against kmod.
2219 Although technically you can either build test_kmod as a module or
2220 into the kernel we disallow building it into the kernel since
2221 it stress tests request_module() and this will very likely cause
2222 some issues by taking over precious threads available from other
2223 module load requests, ultimately this could be fatal.
2227 tools/testing/selftests/kmod/kmod.sh --help
2231 config TEST_DEBUG_VIRTUAL
2232 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2233 depends on DEBUG_VIRTUAL
2235 Test the kernel's ability to detect incorrect calls to
2236 virt_to_phys() done against the non-linear part of the
2237 kernel's virtual address map.
2241 config TEST_MEMCAT_P
2242 tristate "Test memcat_p() helper function"
2244 Test the memcat_p() helper for correctly merging two
2245 pointer arrays together.
2249 config TEST_LIVEPATCH
2250 tristate "Test livepatching"
2252 depends on DYNAMIC_DEBUG
2253 depends on LIVEPATCH
2256 Test kernel livepatching features for correctness. The tests will
2257 load test modules that will be livepatched in various scenarios.
2259 To run all the livepatching tests:
2261 make -C tools/testing/selftests TARGETS=livepatch run_tests
2263 Alternatively, individual tests may be invoked:
2265 tools/testing/selftests/livepatch/test-callbacks.sh
2266 tools/testing/selftests/livepatch/test-livepatch.sh
2267 tools/testing/selftests/livepatch/test-shadow-vars.sh
2272 tristate "Perform selftest on object aggreration manager"
2276 Enable this option to test object aggregation manager on boot
2280 config TEST_STACKINIT
2281 tristate "Test level of stack variable initialization"
2283 Test if the kernel is zero-initializing stack variables and
2284 padding. Coverage is controlled by compiler flags,
2285 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2286 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2291 tristate "Test heap/page initialization"
2293 Test if the kernel is zero-initializing heap and page allocations.
2294 This can be useful to test init_on_alloc and init_on_free features.
2299 tristate "Test HMM (Heterogeneous Memory Management)"
2300 depends on TRANSPARENT_HUGEPAGE
2301 depends on DEVICE_PRIVATE
2305 This is a pseudo device driver solely for testing HMM.
2306 Say M here if you want to build the HMM test module.
2307 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2311 endif # RUNTIME_TESTING_MENU
2316 This option adds a kernel parameter 'memtest', which allows memtest
2318 memtest=0, mean disabled; -- default
2319 memtest=1, mean do 1 test pattern;
2321 memtest=17, mean do 17 test patterns.
2322 If you are unsure how to answer this question, answer N.
2326 config HYPERV_TESTING
2327 bool "Microsoft Hyper-V driver testing"
2329 depends on HYPERV && DEBUG_FS
2331 Select this option to enable Hyper-V vmbus testing.
2333 endmenu # "Kernel Testing and Coverage"
2335 endmenu # Kernel hacking