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/.
480 prompt "Debugfs default access"
482 default DEBUG_FS_ALLOW_ALL
484 This selects the default access restrictions for debugfs.
485 It can be overridden with kernel command line option
486 debugfs=[on,no-mount,off]. The restrictions apply for API access
487 and filesystem registration.
489 config DEBUG_FS_ALLOW_ALL
492 No restrictions apply. Both API and filesystem registration
493 is on. This is the normal default operation.
495 config DEBUG_FS_DISALLOW_MOUNT
496 bool "Do not register debugfs as filesystem"
498 The API is open but filesystem is not loaded. Clients can still do
499 their work and read with debug tools that do not need
502 config DEBUG_FS_ALLOW_NONE
505 Access is off. Clients get -PERM when trying to create nodes in
506 debugfs tree and debugfs is not registered as a filesystem.
507 Client can then back-off or continue without debugfs access.
511 source "lib/Kconfig.kgdb"
513 source "lib/Kconfig.ubsan"
518 bool "Kernel debugging"
520 Say Y here if you are developing drivers or trying to debug and
521 identify kernel problems.
524 bool "Miscellaneous debug code"
526 depends on DEBUG_KERNEL
528 Say Y here if you need to enable miscellaneous debug code that should
529 be under a more specific debug option but isn't.
532 menu "Memory Debugging"
534 source "mm/Kconfig.debug"
537 bool "Debug object operations"
538 depends on DEBUG_KERNEL
540 If you say Y here, additional code will be inserted into the
541 kernel to track the life time of various objects and validate
542 the operations on those objects.
544 config DEBUG_OBJECTS_SELFTEST
545 bool "Debug objects selftest"
546 depends on DEBUG_OBJECTS
548 This enables the selftest of the object debug code.
550 config DEBUG_OBJECTS_FREE
551 bool "Debug objects in freed memory"
552 depends on DEBUG_OBJECTS
554 This enables checks whether a k/v free operation frees an area
555 which contains an object which has not been deactivated
556 properly. This can make kmalloc/kfree-intensive workloads
559 config DEBUG_OBJECTS_TIMERS
560 bool "Debug timer objects"
561 depends on DEBUG_OBJECTS
563 If you say Y here, additional code will be inserted into the
564 timer routines to track the life time of timer objects and
565 validate the timer operations.
567 config DEBUG_OBJECTS_WORK
568 bool "Debug work objects"
569 depends on DEBUG_OBJECTS
571 If you say Y here, additional code will be inserted into the
572 work queue routines to track the life time of work objects and
573 validate the work operations.
575 config DEBUG_OBJECTS_RCU_HEAD
576 bool "Debug RCU callbacks objects"
577 depends on DEBUG_OBJECTS
579 Enable this to turn on debugging of RCU list heads (call_rcu() usage).
581 config DEBUG_OBJECTS_PERCPU_COUNTER
582 bool "Debug percpu counter objects"
583 depends on DEBUG_OBJECTS
585 If you say Y here, additional code will be inserted into the
586 percpu counter routines to track the life time of percpu counter
587 objects and validate the percpu counter operations.
589 config DEBUG_OBJECTS_ENABLE_DEFAULT
590 int "debug_objects bootup default value (0-1)"
593 depends on DEBUG_OBJECTS
595 Debug objects boot parameter default value
598 bool "Debug slab memory allocations"
599 depends on DEBUG_KERNEL && SLAB
601 Say Y here to have the kernel do limited verification on memory
602 allocation as well as poisoning memory on free to catch use of freed
603 memory. This can make kmalloc/kfree-intensive workloads much slower.
606 bool "SLUB debugging on by default"
607 depends on SLUB && SLUB_DEBUG
610 Boot with debugging on by default. SLUB boots by default with
611 the runtime debug capabilities switched off. Enabling this is
612 equivalent to specifying the "slub_debug" parameter on boot.
613 There is no support for more fine grained debug control like
614 possible with slub_debug=xxx. SLUB debugging may be switched
615 off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying
620 bool "Enable SLUB performance statistics"
621 depends on SLUB && SYSFS
623 SLUB statistics are useful to debug SLUBs allocation behavior in
624 order find ways to optimize the allocator. This should never be
625 enabled for production use since keeping statistics slows down
626 the allocator by a few percentage points. The slabinfo command
627 supports the determination of the most active slabs to figure
628 out which slabs are relevant to a particular load.
629 Try running: slabinfo -DA
631 config HAVE_DEBUG_KMEMLEAK
634 config DEBUG_KMEMLEAK
635 bool "Kernel memory leak detector"
636 depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK
638 select STACKTRACE if STACKTRACE_SUPPORT
642 Say Y here if you want to enable the memory leak
643 detector. The memory allocation/freeing is traced in a way
644 similar to the Boehm's conservative garbage collector, the
645 difference being that the orphan objects are not freed but
646 only shown in /sys/kernel/debug/kmemleak. Enabling this
647 feature will introduce an overhead to memory
648 allocations. See Documentation/dev-tools/kmemleak.rst for more
651 Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
652 of finding leaks due to the slab objects poisoning.
654 In order to access the kmemleak file, debugfs needs to be
655 mounted (usually at /sys/kernel/debug).
657 config DEBUG_KMEMLEAK_MEM_POOL_SIZE
658 int "Kmemleak memory pool size"
659 depends on DEBUG_KMEMLEAK
663 Kmemleak must track all the memory allocations to avoid
664 reporting false positives. Since memory may be allocated or
665 freed before kmemleak is fully initialised, use a static pool
666 of metadata objects to track such callbacks. After kmemleak is
667 fully initialised, this memory pool acts as an emergency one
668 if slab allocations fail.
670 config DEBUG_KMEMLEAK_TEST
671 tristate "Simple test for the kernel memory leak detector"
672 depends on DEBUG_KMEMLEAK && m
674 This option enables a module that explicitly leaks memory.
678 config DEBUG_KMEMLEAK_DEFAULT_OFF
679 bool "Default kmemleak to off"
680 depends on DEBUG_KMEMLEAK
682 Say Y here to disable kmemleak by default. It can then be enabled
683 on the command line via kmemleak=on.
685 config DEBUG_KMEMLEAK_AUTO_SCAN
686 bool "Enable kmemleak auto scan thread on boot up"
688 depends on DEBUG_KMEMLEAK
690 Depending on the cpu, kmemleak scan may be cpu intensive and can
691 stall user tasks at times. This option enables/disables automatic
692 kmemleak scan at boot up.
694 Say N here to disable kmemleak auto scan thread to stop automatic
695 scanning. Disabling this option disables automatic reporting of
700 config DEBUG_STACK_USAGE
701 bool "Stack utilization instrumentation"
702 depends on DEBUG_KERNEL && !IA64
704 Enables the display of the minimum amount of free stack which each
705 task has ever had available in the sysrq-T and sysrq-P debug output.
707 This option will slow down process creation somewhat.
709 config SCHED_STACK_END_CHECK
710 bool "Detect stack corruption on calls to schedule()"
711 depends on DEBUG_KERNEL
714 This option checks for a stack overrun on calls to schedule().
715 If the stack end location is found to be over written always panic as
716 the content of the corrupted region can no longer be trusted.
717 This is to ensure no erroneous behaviour occurs which could result in
718 data corruption or a sporadic crash at a later stage once the region
719 is examined. The runtime overhead introduced is minimal.
721 config ARCH_HAS_DEBUG_VM_PGTABLE
724 An architecture should select this when it can successfully
725 build and run DEBUG_VM_PGTABLE.
729 depends on DEBUG_KERNEL
731 Enable this to turn on extended checks in the virtual-memory system
732 that may impact performance.
736 config DEBUG_VM_VMACACHE
737 bool "Debug VMA caching"
740 Enable this to turn on VMA caching debug information. Doing so
741 can cause significant overhead, so only enable it in non-production
747 bool "Debug VM red-black trees"
750 Enable VM red-black tree debugging information and extra validations.
754 config DEBUG_VM_PGFLAGS
755 bool "Debug page-flags operations"
758 Enables extra validation on page flags operations.
762 config DEBUG_VM_PGTABLE
763 bool "Debug arch page table for semantics compliance"
765 depends on ARCH_HAS_DEBUG_VM_PGTABLE
766 default y if DEBUG_VM
768 This option provides a debug method which can be used to test
769 architecture page table helper functions on various platforms in
770 verifying if they comply with expected generic MM semantics. This
771 will help architecture code in making sure that any changes or
772 new additions of these helpers still conform to expected
773 semantics of the generic MM. Platforms will have to opt in for
774 this through ARCH_HAS_DEBUG_VM_PGTABLE.
778 config ARCH_HAS_DEBUG_VIRTUAL
782 bool "Debug VM translations"
783 depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
785 Enable some costly sanity checks in virtual to page code. This can
786 catch mistakes with virt_to_page() and friends.
790 config DEBUG_NOMMU_REGIONS
791 bool "Debug the global anon/private NOMMU mapping region tree"
792 depends on DEBUG_KERNEL && !MMU
794 This option causes the global tree of anonymous and private mapping
795 regions to be regularly checked for invalid topology.
797 config DEBUG_MEMORY_INIT
798 bool "Debug memory initialisation" if EXPERT
801 Enable this for additional checks during memory initialisation.
802 The sanity checks verify aspects of the VM such as the memory model
803 and other information provided by the architecture. Verbose
804 information will be printed at KERN_DEBUG loglevel depending
805 on the mminit_loglevel= command-line option.
809 config MEMORY_NOTIFIER_ERROR_INJECT
810 tristate "Memory hotplug notifier error injection module"
811 depends on MEMORY_HOTPLUG_SPARSE && NOTIFIER_ERROR_INJECTION
813 This option provides the ability to inject artificial errors to
814 memory hotplug notifier chain callbacks. It is controlled through
815 debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
817 If the notifier call chain should be failed with some events
818 notified, write the error code to "actions/<notifier event>/error".
820 Example: Inject memory hotplug offline error (-12 == -ENOMEM)
822 # cd /sys/kernel/debug/notifier-error-inject/memory
823 # echo -12 > actions/MEM_GOING_OFFLINE/error
824 # echo offline > /sys/devices/system/memory/memoryXXX/state
825 bash: echo: write error: Cannot allocate memory
827 To compile this code as a module, choose M here: the module will
828 be called memory-notifier-error-inject.
832 config DEBUG_PER_CPU_MAPS
833 bool "Debug access to per_cpu maps"
834 depends on DEBUG_KERNEL
837 Say Y to verify that the per_cpu map being accessed has
838 been set up. This adds a fair amount of code to kernel memory
839 and decreases performance.
844 bool "Highmem debugging"
845 depends on DEBUG_KERNEL && HIGHMEM
847 This option enables additional error checking for high memory
848 systems. Disable for production systems.
850 config HAVE_DEBUG_STACKOVERFLOW
853 config DEBUG_STACKOVERFLOW
854 bool "Check for stack overflows"
855 depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
857 Say Y here if you want to check for overflows of kernel, IRQ
858 and exception stacks (if your architecture uses them). This
859 option will show detailed messages if free stack space drops
860 below a certain limit.
862 These kinds of bugs usually occur when call-chains in the
863 kernel get too deep, especially when interrupts are
866 Use this in cases where you see apparently random memory
867 corruption, especially if it appears in 'struct thread_info'
869 If in doubt, say "N".
871 source "lib/Kconfig.kasan"
873 endmenu # "Memory Debugging"
876 bool "Debug shared IRQ handlers"
877 depends on DEBUG_KERNEL
879 Enable this to generate a spurious interrupt just before a shared
880 interrupt handler is deregistered (generating one when registering
881 is currently disabled). Drivers need to handle this correctly. Some
882 don't and need to be caught.
884 menu "Debug Oops, Lockups and Hangs"
889 Say Y here to enable the kernel to panic when it oopses. This
890 has the same effect as setting oops=panic on the kernel command
893 This feature is useful to ensure that the kernel does not do
894 anything erroneous after an oops which could result in data
895 corruption or other issues.
899 config PANIC_ON_OOPS_VALUE
902 default 0 if !PANIC_ON_OOPS
903 default 1 if PANIC_ON_OOPS
909 Set the timeout value (in seconds) until a reboot occurs when the
910 the kernel panics. If n = 0, then we wait forever. A timeout
911 value n > 0 will wait n seconds before rebooting, while a timeout
912 value n < 0 will reboot immediately.
914 config LOCKUP_DETECTOR
917 config SOFTLOCKUP_DETECTOR
918 bool "Detect Soft Lockups"
919 depends on DEBUG_KERNEL && !S390
920 select LOCKUP_DETECTOR
922 Say Y here to enable the kernel to act as a watchdog to detect
925 Softlockups are bugs that cause the kernel to loop in kernel
926 mode for more than 20 seconds, without giving other tasks a
927 chance to run. The current stack trace is displayed upon
928 detection and the system will stay locked up.
930 config BOOTPARAM_SOFTLOCKUP_PANIC
931 bool "Panic (Reboot) On Soft Lockups"
932 depends on SOFTLOCKUP_DETECTOR
934 Say Y here to enable the kernel to panic on "soft lockups",
935 which are bugs that cause the kernel to loop in kernel
936 mode for more than 20 seconds (configurable using the watchdog_thresh
937 sysctl), without giving other tasks a chance to run.
939 The panic can be used in combination with panic_timeout,
940 to cause the system to reboot automatically after a
941 lockup has been detected. This feature is useful for
942 high-availability systems that have uptime guarantees and
943 where a lockup must be resolved ASAP.
947 config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE
949 depends on SOFTLOCKUP_DETECTOR
951 default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
952 default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
954 config HARDLOCKUP_DETECTOR_PERF
956 select SOFTLOCKUP_DETECTOR
959 # Enables a timestamp based low pass filter to compensate for perf based
960 # hard lockup detection which runs too fast due to turbo modes.
962 config HARDLOCKUP_CHECK_TIMESTAMP
966 # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
967 # lockup detector rather than the perf based detector.
969 config HARDLOCKUP_DETECTOR
970 bool "Detect Hard Lockups"
971 depends on DEBUG_KERNEL && !S390
972 depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
973 select LOCKUP_DETECTOR
974 select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
975 select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
977 Say Y here to enable the kernel to act as a watchdog to detect
980 Hardlockups are bugs that cause the CPU to loop in kernel mode
981 for more than 10 seconds, without letting other interrupts have a
982 chance to run. The current stack trace is displayed upon detection
983 and the system will stay locked up.
985 config BOOTPARAM_HARDLOCKUP_PANIC
986 bool "Panic (Reboot) On Hard Lockups"
987 depends on HARDLOCKUP_DETECTOR
989 Say Y here to enable the kernel to panic on "hard lockups",
990 which are bugs that cause the kernel to loop in kernel
991 mode with interrupts disabled for more than 10 seconds (configurable
992 using the watchdog_thresh sysctl).
996 config BOOTPARAM_HARDLOCKUP_PANIC_VALUE
998 depends on HARDLOCKUP_DETECTOR
1000 default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
1001 default 1 if BOOTPARAM_HARDLOCKUP_PANIC
1003 config DETECT_HUNG_TASK
1004 bool "Detect Hung Tasks"
1005 depends on DEBUG_KERNEL
1006 default SOFTLOCKUP_DETECTOR
1008 Say Y here to enable the kernel to detect "hung tasks",
1009 which are bugs that cause the task to be stuck in
1010 uninterruptible "D" state indefinitely.
1012 When a hung task is detected, the kernel will print the
1013 current stack trace (which you should report), but the
1014 task will stay in uninterruptible state. If lockdep is
1015 enabled then all held locks will also be reported. This
1016 feature has negligible overhead.
1018 config DEFAULT_HUNG_TASK_TIMEOUT
1019 int "Default timeout for hung task detection (in seconds)"
1020 depends on DETECT_HUNG_TASK
1023 This option controls the default timeout (in seconds) used
1024 to determine when a task has become non-responsive and should
1027 It can be adjusted at runtime via the kernel.hung_task_timeout_secs
1028 sysctl or by writing a value to
1029 /proc/sys/kernel/hung_task_timeout_secs.
1031 A timeout of 0 disables the check. The default is two minutes.
1032 Keeping the default should be fine in most cases.
1034 config BOOTPARAM_HUNG_TASK_PANIC
1035 bool "Panic (Reboot) On Hung Tasks"
1036 depends on DETECT_HUNG_TASK
1038 Say Y here to enable the kernel to panic on "hung tasks",
1039 which are bugs that cause the kernel to leave a task stuck
1040 in uninterruptible "D" state.
1042 The panic can be used in combination with panic_timeout,
1043 to cause the system to reboot automatically after a
1044 hung task has been detected. This feature is useful for
1045 high-availability systems that have uptime guarantees and
1046 where a hung tasks must be resolved ASAP.
1050 config BOOTPARAM_HUNG_TASK_PANIC_VALUE
1052 depends on DETECT_HUNG_TASK
1054 default 0 if !BOOTPARAM_HUNG_TASK_PANIC
1055 default 1 if BOOTPARAM_HUNG_TASK_PANIC
1058 bool "Detect Workqueue Stalls"
1059 depends on DEBUG_KERNEL
1061 Say Y here to enable stall detection on workqueues. If a
1062 worker pool doesn't make forward progress on a pending work
1063 item for over a given amount of time, 30s by default, a
1064 warning message is printed along with dump of workqueue
1065 state. This can be configured through kernel parameter
1066 "workqueue.watchdog_thresh" and its sysfs counterpart.
1069 tristate "Test module to generate lockups"
1071 This builds the "test_lockup" module that helps to make sure
1072 that watchdogs and lockup detectors are working properly.
1074 Depending on module parameters it could emulate soft or hard
1075 lockup, "hung task", or locking arbitrary lock for a long time.
1076 Also it could generate series of lockups with cooling-down periods.
1080 endmenu # "Debug lockups and hangs"
1082 menu "Scheduler Debugging"
1085 bool "Collect scheduler debugging info"
1086 depends on DEBUG_KERNEL && PROC_FS
1089 If you say Y here, the /proc/sched_debug file will be provided
1090 that can help debug the scheduler. The runtime overhead of this
1098 bool "Collect scheduler statistics"
1099 depends on DEBUG_KERNEL && PROC_FS
1102 If you say Y here, additional code will be inserted into the
1103 scheduler and related routines to collect statistics about
1104 scheduler behavior and provide them in /proc/schedstat. These
1105 stats may be useful for both tuning and debugging the scheduler
1106 If you aren't debugging the scheduler or trying to tune a specific
1107 application, you can say N to avoid the very slight overhead
1112 config DEBUG_TIMEKEEPING
1113 bool "Enable extra timekeeping sanity checking"
1115 This option will enable additional timekeeping sanity checks
1116 which may be helpful when diagnosing issues where timekeeping
1117 problems are suspected.
1119 This may include checks in the timekeeping hotpaths, so this
1120 option may have a (very small) performance impact to some
1125 config DEBUG_PREEMPT
1126 bool "Debug preemptible kernel"
1127 depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
1130 If you say Y here then the kernel will use a debug variant of the
1131 commonly used smp_processor_id() function and will print warnings
1132 if kernel code uses it in a preemption-unsafe way. Also, the kernel
1133 will detect preemption count underflows.
1135 menu "Lock Debugging (spinlocks, mutexes, etc...)"
1137 config LOCK_DEBUGGING_SUPPORT
1139 depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
1142 config PROVE_LOCKING
1143 bool "Lock debugging: prove locking correctness"
1144 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1146 select DEBUG_SPINLOCK
1147 select DEBUG_MUTEXES
1148 select DEBUG_RT_MUTEXES if RT_MUTEXES
1150 select DEBUG_WW_MUTEX_SLOWPATH
1151 select DEBUG_LOCK_ALLOC
1152 select PREEMPT_COUNT if !ARCH_NO_PREEMPT
1153 select TRACE_IRQFLAGS
1156 This feature enables the kernel to prove that all locking
1157 that occurs in the kernel runtime is mathematically
1158 correct: that under no circumstance could an arbitrary (and
1159 not yet triggered) combination of observed locking
1160 sequences (on an arbitrary number of CPUs, running an
1161 arbitrary number of tasks and interrupt contexts) cause a
1164 In short, this feature enables the kernel to report locking
1165 related deadlocks before they actually occur.
1167 The proof does not depend on how hard and complex a
1168 deadlock scenario would be to trigger: how many
1169 participant CPUs, tasks and irq-contexts would be needed
1170 for it to trigger. The proof also does not depend on
1171 timing: if a race and a resulting deadlock is possible
1172 theoretically (no matter how unlikely the race scenario
1173 is), it will be proven so and will immediately be
1174 reported by the kernel (once the event is observed that
1175 makes the deadlock theoretically possible).
1177 If a deadlock is impossible (i.e. the locking rules, as
1178 observed by the kernel, are mathematically correct), the
1179 kernel reports nothing.
1181 NOTE: this feature can also be enabled for rwlocks, mutexes
1182 and rwsems - in which case all dependencies between these
1183 different locking variants are observed and mapped too, and
1184 the proof of observed correctness is also maintained for an
1185 arbitrary combination of these separate locking variants.
1187 For more details, see Documentation/locking/lockdep-design.rst.
1189 config PROVE_RAW_LOCK_NESTING
1190 bool "Enable raw_spinlock - spinlock nesting checks"
1191 depends on PROVE_LOCKING
1194 Enable the raw_spinlock vs. spinlock nesting checks which ensure
1195 that the lock nesting rules for PREEMPT_RT enabled kernels are
1198 NOTE: There are known nesting problems. So if you enable this
1199 option expect lockdep splats until these problems have been fully
1200 addressed which is work in progress. This config switch allows to
1201 identify and analyze these problems. It will be removed and the
1202 check permanentely enabled once the main issues have been fixed.
1204 If unsure, select N.
1207 bool "Lock usage statistics"
1208 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1210 select DEBUG_SPINLOCK
1211 select DEBUG_MUTEXES
1212 select DEBUG_RT_MUTEXES if RT_MUTEXES
1213 select DEBUG_LOCK_ALLOC
1216 This feature enables tracking lock contention points
1218 For more details, see Documentation/locking/lockstat.rst
1220 This also enables lock events required by "perf lock",
1222 If you want to use "perf lock", you also need to turn on
1223 CONFIG_EVENT_TRACING.
1225 CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
1226 (CONFIG_LOCKDEP defines "acquire" and "release" events.)
1228 config DEBUG_RT_MUTEXES
1229 bool "RT Mutex debugging, deadlock detection"
1230 depends on DEBUG_KERNEL && RT_MUTEXES
1232 This allows rt mutex semantics violations and rt mutex related
1233 deadlocks (lockups) to be detected and reported automatically.
1235 config DEBUG_SPINLOCK
1236 bool "Spinlock and rw-lock debugging: basic checks"
1237 depends on DEBUG_KERNEL
1238 select UNINLINE_SPIN_UNLOCK
1240 Say Y here and build SMP to catch missing spinlock initialization
1241 and certain other kinds of spinlock errors commonly made. This is
1242 best used in conjunction with the NMI watchdog so that spinlock
1243 deadlocks are also debuggable.
1245 config DEBUG_MUTEXES
1246 bool "Mutex debugging: basic checks"
1247 depends on DEBUG_KERNEL
1249 This feature allows mutex semantics violations to be detected and
1252 config DEBUG_WW_MUTEX_SLOWPATH
1253 bool "Wait/wound mutex debugging: Slowpath testing"
1254 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1255 select DEBUG_LOCK_ALLOC
1256 select DEBUG_SPINLOCK
1257 select DEBUG_MUTEXES
1259 This feature enables slowpath testing for w/w mutex users by
1260 injecting additional -EDEADLK wound/backoff cases. Together with
1261 the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
1262 will test all possible w/w mutex interface abuse with the
1263 exception of simply not acquiring all the required locks.
1264 Note that this feature can introduce significant overhead, so
1265 it really should not be enabled in a production or distro kernel,
1266 even a debug kernel. If you are a driver writer, enable it. If
1267 you are a distro, do not.
1270 bool "RW Semaphore debugging: basic checks"
1271 depends on DEBUG_KERNEL
1273 This debugging feature allows mismatched rw semaphore locks
1274 and unlocks to be detected and reported.
1276 config DEBUG_LOCK_ALLOC
1277 bool "Lock debugging: detect incorrect freeing of live locks"
1278 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1279 select DEBUG_SPINLOCK
1280 select DEBUG_MUTEXES
1281 select DEBUG_RT_MUTEXES if RT_MUTEXES
1284 This feature will check whether any held lock (spinlock, rwlock,
1285 mutex or rwsem) is incorrectly freed by the kernel, via any of the
1286 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1287 vfree(), etc.), whether a live lock is incorrectly reinitialized via
1288 spin_lock_init()/mutex_init()/etc., or whether there is any lock
1289 held during task exit.
1293 depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
1295 select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
1299 config LOCKDEP_SMALL
1302 config DEBUG_LOCKDEP
1303 bool "Lock dependency engine debugging"
1304 depends on DEBUG_KERNEL && LOCKDEP
1306 If you say Y here, the lock dependency engine will do
1307 additional runtime checks to debug itself, at the price
1308 of more runtime overhead.
1310 config DEBUG_ATOMIC_SLEEP
1311 bool "Sleep inside atomic section checking"
1312 select PREEMPT_COUNT
1313 depends on DEBUG_KERNEL
1314 depends on !ARCH_NO_PREEMPT
1316 If you say Y here, various routines which may sleep will become very
1317 noisy if they are called inside atomic sections: when a spinlock is
1318 held, inside an rcu read side critical section, inside preempt disabled
1319 sections, inside an interrupt, etc...
1321 config DEBUG_LOCKING_API_SELFTESTS
1322 bool "Locking API boot-time self-tests"
1323 depends on DEBUG_KERNEL
1325 Say Y here if you want the kernel to run a short self-test during
1326 bootup. The self-test checks whether common types of locking bugs
1327 are detected by debugging mechanisms or not. (if you disable
1328 lock debugging then those bugs wont be detected of course.)
1329 The following locking APIs are covered: spinlocks, rwlocks,
1332 config LOCK_TORTURE_TEST
1333 tristate "torture tests for locking"
1334 depends on DEBUG_KERNEL
1337 This option provides a kernel module that runs torture tests
1338 on kernel locking primitives. The kernel module may be built
1339 after the fact on the running kernel to be tested, if desired.
1341 Say Y here if you want kernel locking-primitive torture tests
1342 to be built into the kernel.
1343 Say M if you want these torture tests to build as a module.
1344 Say N if you are unsure.
1346 config WW_MUTEX_SELFTEST
1347 tristate "Wait/wound mutex selftests"
1349 This option provides a kernel module that runs tests on the
1350 on the struct ww_mutex locking API.
1352 It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
1353 with this test harness.
1355 Say M if you want these self tests to build as a module.
1356 Say N if you are unsure.
1358 endmenu # lock debugging
1360 config TRACE_IRQFLAGS
1361 depends on TRACE_IRQFLAGS_SUPPORT
1364 Enables hooks to interrupt enabling and disabling for
1365 either tracing or lock debugging.
1367 config TRACE_IRQFLAGS_NMI
1369 depends on TRACE_IRQFLAGS
1370 depends on TRACE_IRQFLAGS_NMI_SUPPORT
1373 bool "Stack backtrace support"
1374 depends on STACKTRACE_SUPPORT
1376 This option causes the kernel to create a /proc/pid/stack for
1377 every process, showing its current stack trace.
1378 It is also used by various kernel debugging features that require
1379 stack trace generation.
1381 config WARN_ALL_UNSEEDED_RANDOM
1382 bool "Warn for all uses of unseeded randomness"
1385 Some parts of the kernel contain bugs relating to their use of
1386 cryptographically secure random numbers before it's actually possible
1387 to generate those numbers securely. This setting ensures that these
1388 flaws don't go unnoticed, by enabling a message, should this ever
1389 occur. This will allow people with obscure setups to know when things
1390 are going wrong, so that they might contact developers about fixing
1393 Unfortunately, on some models of some architectures getting
1394 a fully seeded CRNG is extremely difficult, and so this can
1395 result in dmesg getting spammed for a surprisingly long
1396 time. This is really bad from a security perspective, and
1397 so architecture maintainers really need to do what they can
1398 to get the CRNG seeded sooner after the system is booted.
1399 However, since users cannot do anything actionable to
1400 address this, by default the kernel will issue only a single
1401 warning for the first use of unseeded randomness.
1403 Say Y here if you want to receive warnings for all uses of
1404 unseeded randomness. This will be of use primarily for
1405 those developers interested in improving the security of
1406 Linux kernels running on their architecture (or
1409 config DEBUG_KOBJECT
1410 bool "kobject debugging"
1411 depends on DEBUG_KERNEL
1413 If you say Y here, some extra kobject debugging messages will be sent
1416 config DEBUG_KOBJECT_RELEASE
1417 bool "kobject release debugging"
1418 depends on DEBUG_OBJECTS_TIMERS
1420 kobjects are reference counted objects. This means that their
1421 last reference count put is not predictable, and the kobject can
1422 live on past the point at which a driver decides to drop it's
1423 initial reference to the kobject gained on allocation. An
1424 example of this would be a struct device which has just been
1427 However, some buggy drivers assume that after such an operation,
1428 the memory backing the kobject can be immediately freed. This
1429 goes completely against the principles of a refcounted object.
1431 If you say Y here, the kernel will delay the release of kobjects
1432 on the last reference count to improve the visibility of this
1433 kind of kobject release bug.
1435 config HAVE_DEBUG_BUGVERBOSE
1438 menu "Debug kernel data structures"
1441 bool "Debug linked list manipulation"
1442 depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
1444 Enable this to turn on extended checks in the linked-list
1450 bool "Debug priority linked list manipulation"
1451 depends on DEBUG_KERNEL
1453 Enable this to turn on extended checks in the priority-ordered
1454 linked-list (plist) walking routines. This checks the entire
1455 list multiple times during each manipulation.
1460 bool "Debug SG table operations"
1461 depends on DEBUG_KERNEL
1463 Enable this to turn on checks on scatter-gather tables. This can
1464 help find problems with drivers that do not properly initialize
1469 config DEBUG_NOTIFIERS
1470 bool "Debug notifier call chains"
1471 depends on DEBUG_KERNEL
1473 Enable this to turn on sanity checking for notifier call chains.
1474 This is most useful for kernel developers to make sure that
1475 modules properly unregister themselves from notifier chains.
1476 This is a relatively cheap check but if you care about maximum
1479 config BUG_ON_DATA_CORRUPTION
1480 bool "Trigger a BUG when data corruption is detected"
1483 Select this option if the kernel should BUG when it encounters
1484 data corruption in kernel memory structures when they get checked
1491 config DEBUG_CREDENTIALS
1492 bool "Debug credential management"
1493 depends on DEBUG_KERNEL
1495 Enable this to turn on some debug checking for credential
1496 management. The additional code keeps track of the number of
1497 pointers from task_structs to any given cred struct, and checks to
1498 see that this number never exceeds the usage count of the cred
1501 Furthermore, if SELinux is enabled, this also checks that the
1502 security pointer in the cred struct is never seen to be invalid.
1506 source "kernel/rcu/Kconfig.debug"
1508 config DEBUG_WQ_FORCE_RR_CPU
1509 bool "Force round-robin CPU selection for unbound work items"
1510 depends on DEBUG_KERNEL
1513 Workqueue used to implicitly guarantee that work items queued
1514 without explicit CPU specified are put on the local CPU. This
1515 guarantee is no longer true and while local CPU is still
1516 preferred work items may be put on foreign CPUs. Kernel
1517 parameter "workqueue.debug_force_rr_cpu" is added to force
1518 round-robin CPU selection to flush out usages which depend on the
1519 now broken guarantee. This config option enables the debug
1520 feature by default. When enabled, memory and cache locality will
1523 config DEBUG_BLOCK_EXT_DEVT
1524 bool "Force extended block device numbers and spread them"
1525 depends on DEBUG_KERNEL
1529 BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
1530 SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
1531 YOU ARE DOING. Distros, please enable this and fix whatever
1534 Conventionally, block device numbers are allocated from
1535 predetermined contiguous area. However, extended block area
1536 may introduce non-contiguous block device numbers. This
1537 option forces most block device numbers to be allocated from
1538 the extended space and spreads them to discover kernel or
1539 userland code paths which assume predetermined contiguous
1540 device number allocation.
1542 Note that turning on this debug option shuffles all the
1543 device numbers for all IDE and SCSI devices including libata
1544 ones, so root partition specified using device number
1545 directly (via rdev or root=MAJ:MIN) won't work anymore.
1546 Textual device names (root=/dev/sdXn) will continue to work.
1548 Say N if you are unsure.
1550 config CPU_HOTPLUG_STATE_CONTROL
1551 bool "Enable CPU hotplug state control"
1552 depends on DEBUG_KERNEL
1553 depends on HOTPLUG_CPU
1556 Allows to write steps between "offline" and "online" to the CPUs
1557 sysfs target file so states can be stepped granular. This is a debug
1558 option for now as the hotplug machinery cannot be stopped and
1559 restarted at arbitrary points yet.
1561 Say N if your are unsure.
1564 bool "Latency measuring infrastructure"
1565 depends on DEBUG_KERNEL
1566 depends on STACKTRACE_SUPPORT
1568 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1575 Enable this option if you want to use the LatencyTOP tool
1576 to find out which userspace is blocking on what kernel operations.
1578 source "kernel/trace/Kconfig"
1580 config PROVIDE_OHCI1394_DMA_INIT
1581 bool "Remote debugging over FireWire early on boot"
1582 depends on PCI && X86
1584 If you want to debug problems which hang or crash the kernel early
1585 on boot and the crashing machine has a FireWire port, you can use
1586 this feature to remotely access the memory of the crashed machine
1587 over FireWire. This employs remote DMA as part of the OHCI1394
1588 specification which is now the standard for FireWire controllers.
1590 With remote DMA, you can monitor the printk buffer remotely using
1591 firescope and access all memory below 4GB using fireproxy from gdb.
1592 Even controlling a kernel debugger is possible using remote DMA.
1596 If ohci1394_dma=early is used as boot parameter, it will initialize
1597 all OHCI1394 controllers which are found in the PCI config space.
1599 As all changes to the FireWire bus such as enabling and disabling
1600 devices cause a bus reset and thereby disable remote DMA for all
1601 devices, be sure to have the cable plugged and FireWire enabled on
1602 the debugging host before booting the debug target for debugging.
1604 This code (~1k) is freed after boot. By then, the firewire stack
1605 in charge of the OHCI-1394 controllers should be used instead.
1607 See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1609 source "samples/Kconfig"
1611 source "lib/Kconfig.kcsan"
1613 config ARCH_HAS_DEVMEM_IS_ALLOWED
1616 config STRICT_DEVMEM
1617 bool "Filter access to /dev/mem"
1618 depends on MMU && DEVMEM
1619 depends on ARCH_HAS_DEVMEM_IS_ALLOWED
1620 default y if PPC || X86 || ARM64
1622 If this option is disabled, you allow userspace (root) access to all
1623 of memory, including kernel and userspace memory. Accidental
1624 access to this is obviously disastrous, but specific access can
1625 be used by people debugging the kernel. Note that with PAT support
1626 enabled, even in this case there are restrictions on /dev/mem
1627 use due to the cache aliasing requirements.
1629 If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
1630 file only allows userspace access to PCI space and the BIOS code and
1631 data regions. This is sufficient for dosemu and X and all common
1636 config IO_STRICT_DEVMEM
1637 bool "Filter I/O access to /dev/mem"
1638 depends on STRICT_DEVMEM
1640 If this option is disabled, you allow userspace (root) access to all
1641 io-memory regardless of whether a driver is actively using that
1642 range. Accidental access to this is obviously disastrous, but
1643 specific access can be used by people debugging kernel drivers.
1645 If this option is switched on, the /dev/mem file only allows
1646 userspace access to *idle* io-memory ranges (see /proc/iomem) This
1647 may break traditional users of /dev/mem (dosemu, legacy X, etc...)
1648 if the driver using a given range cannot be disabled.
1652 menu "$(SRCARCH) Debugging"
1654 source "arch/$(SRCARCH)/Kconfig.debug"
1658 menu "Kernel Testing and Coverage"
1660 source "lib/kunit/Kconfig"
1662 config NOTIFIER_ERROR_INJECTION
1663 tristate "Notifier error injection"
1664 depends on DEBUG_KERNEL
1667 This option provides the ability to inject artificial errors to
1668 specified notifier chain callbacks. It is useful to test the error
1669 handling of notifier call chain failures.
1673 config PM_NOTIFIER_ERROR_INJECT
1674 tristate "PM notifier error injection module"
1675 depends on PM && NOTIFIER_ERROR_INJECTION
1676 default m if PM_DEBUG
1678 This option provides the ability to inject artificial errors to
1679 PM notifier chain callbacks. It is controlled through debugfs
1680 interface /sys/kernel/debug/notifier-error-inject/pm
1682 If the notifier call chain should be failed with some events
1683 notified, write the error code to "actions/<notifier event>/error".
1685 Example: Inject PM suspend error (-12 = -ENOMEM)
1687 # cd /sys/kernel/debug/notifier-error-inject/pm/
1688 # echo -12 > actions/PM_SUSPEND_PREPARE/error
1689 # echo mem > /sys/power/state
1690 bash: echo: write error: Cannot allocate memory
1692 To compile this code as a module, choose M here: the module will
1693 be called pm-notifier-error-inject.
1697 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
1698 tristate "OF reconfig notifier error injection module"
1699 depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
1701 This option provides the ability to inject artificial errors to
1702 OF reconfig notifier chain callbacks. It is controlled
1703 through debugfs interface under
1704 /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1706 If the notifier call chain should be failed with some events
1707 notified, write the error code to "actions/<notifier event>/error".
1709 To compile this code as a module, choose M here: the module will
1710 be called of-reconfig-notifier-error-inject.
1714 config NETDEV_NOTIFIER_ERROR_INJECT
1715 tristate "Netdev notifier error injection module"
1716 depends on NET && NOTIFIER_ERROR_INJECTION
1718 This option provides the ability to inject artificial errors to
1719 netdevice notifier chain callbacks. It is controlled through debugfs
1720 interface /sys/kernel/debug/notifier-error-inject/netdev
1722 If the notifier call chain should be failed with some events
1723 notified, write the error code to "actions/<notifier event>/error".
1725 Example: Inject netdevice mtu change error (-22 = -EINVAL)
1727 # cd /sys/kernel/debug/notifier-error-inject/netdev
1728 # echo -22 > actions/NETDEV_CHANGEMTU/error
1729 # ip link set eth0 mtu 1024
1730 RTNETLINK answers: Invalid argument
1732 To compile this code as a module, choose M here: the module will
1733 be called netdev-notifier-error-inject.
1737 config FUNCTION_ERROR_INJECTION
1739 depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
1741 config FAULT_INJECTION
1742 bool "Fault-injection framework"
1743 depends on DEBUG_KERNEL
1745 Provide fault-injection framework.
1746 For more details, see Documentation/fault-injection/.
1749 bool "Fault-injection capability for kmalloc"
1750 depends on FAULT_INJECTION
1751 depends on SLAB || SLUB
1753 Provide fault-injection capability for kmalloc.
1755 config FAIL_PAGE_ALLOC
1756 bool "Fault-injection capability for alloc_pages()"
1757 depends on FAULT_INJECTION
1759 Provide fault-injection capability for alloc_pages().
1761 config FAIL_MAKE_REQUEST
1762 bool "Fault-injection capability for disk IO"
1763 depends on FAULT_INJECTION && BLOCK
1765 Provide fault-injection capability for disk IO.
1767 config FAIL_IO_TIMEOUT
1768 bool "Fault-injection capability for faking disk interrupts"
1769 depends on FAULT_INJECTION && BLOCK
1771 Provide fault-injection capability on end IO handling. This
1772 will make the block layer "forget" an interrupt as configured,
1773 thus exercising the error handling.
1775 Only works with drivers that use the generic timeout handling,
1776 for others it wont do anything.
1779 bool "Fault-injection capability for futexes"
1781 depends on FAULT_INJECTION && FUTEX
1783 Provide fault-injection capability for futexes.
1785 config FAULT_INJECTION_DEBUG_FS
1786 bool "Debugfs entries for fault-injection capabilities"
1787 depends on FAULT_INJECTION && SYSFS && DEBUG_FS
1789 Enable configuration of fault-injection capabilities via debugfs.
1791 config FAIL_FUNCTION
1792 bool "Fault-injection capability for functions"
1793 depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
1795 Provide function-based fault-injection capability.
1796 This will allow you to override a specific function with a return
1797 with given return value. As a result, function caller will see
1798 an error value and have to handle it. This is useful to test the
1799 error handling in various subsystems.
1801 config FAIL_MMC_REQUEST
1802 bool "Fault-injection capability for MMC IO"
1803 depends on FAULT_INJECTION_DEBUG_FS && MMC
1805 Provide fault-injection capability for MMC IO.
1806 This will make the mmc core return data errors. This is
1807 useful to test the error handling in the mmc block device
1808 and to test how the mmc host driver handles retries from
1811 config FAULT_INJECTION_STACKTRACE_FILTER
1812 bool "stacktrace filter for fault-injection capabilities"
1813 depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
1816 select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
1818 Provide stacktrace filter for fault-injection capabilities
1820 config ARCH_HAS_KCOV
1823 An architecture should select this when it can successfully
1824 build and run with CONFIG_KCOV. This typically requires
1825 disabling instrumentation for some early boot code.
1827 config CC_HAS_SANCOV_TRACE_PC
1828 def_bool $(cc-option,-fsanitize-coverage=trace-pc)
1832 bool "Code coverage for fuzzing"
1833 depends on ARCH_HAS_KCOV
1834 depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
1836 select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
1838 KCOV exposes kernel code coverage information in a form suitable
1839 for coverage-guided fuzzing (randomized testing).
1841 If RANDOMIZE_BASE is enabled, PC values will not be stable across
1842 different machines and across reboots. If you need stable PC values,
1843 disable RANDOMIZE_BASE.
1845 For more details, see Documentation/dev-tools/kcov.rst.
1847 config KCOV_ENABLE_COMPARISONS
1848 bool "Enable comparison operands collection by KCOV"
1850 depends on $(cc-option,-fsanitize-coverage=trace-cmp)
1852 KCOV also exposes operands of every comparison in the instrumented
1853 code along with operand sizes and PCs of the comparison instructions.
1854 These operands can be used by fuzzing engines to improve the quality
1855 of fuzzing coverage.
1857 config KCOV_INSTRUMENT_ALL
1858 bool "Instrument all code by default"
1862 If you are doing generic system call fuzzing (like e.g. syzkaller),
1863 then you will want to instrument the whole kernel and you should
1864 say y here. If you are doing more targeted fuzzing (like e.g.
1865 filesystem fuzzing with AFL) then you will want to enable coverage
1866 for more specific subsets of files, and should say n here.
1868 config KCOV_IRQ_AREA_SIZE
1869 hex "Size of interrupt coverage collection area in words"
1873 KCOV uses preallocated per-cpu areas to collect coverage from
1874 soft interrupts. This specifies the size of those areas in the
1875 number of unsigned long words.
1877 menuconfig RUNTIME_TESTING_MENU
1878 bool "Runtime Testing"
1881 if RUNTIME_TESTING_MENU
1884 tristate "Linux Kernel Dump Test Tool Module"
1887 This module enables testing of the different dumping mechanisms by
1888 inducing system failures at predefined crash points.
1889 If you don't need it: say N
1890 Choose M here to compile this code as a module. The module will be
1893 Documentation on how to use the module can be found in
1894 Documentation/fault-injection/provoke-crashes.rst
1896 config TEST_LIST_SORT
1897 tristate "Linked list sorting test"
1898 depends on DEBUG_KERNEL || m
1900 Enable this to turn on 'list_sort()' function test. This test is
1901 executed only once during system boot (so affects only boot time),
1902 or at module load time.
1906 config TEST_MIN_HEAP
1907 tristate "Min heap test"
1908 depends on DEBUG_KERNEL || m
1910 Enable this to turn on min heap function tests. This test is
1911 executed only once during system boot (so affects only boot time),
1912 or at module load time.
1917 tristate "Array-based sort test"
1918 depends on DEBUG_KERNEL || m
1920 This option enables the self-test function of 'sort()' at boot,
1921 or at module load time.
1925 config KPROBES_SANITY_TEST
1926 bool "Kprobes sanity tests"
1927 depends on DEBUG_KERNEL
1930 This option provides for testing basic kprobes functionality on
1931 boot. Samples of kprobe and kretprobe are inserted and
1932 verified for functionality.
1934 Say N if you are unsure.
1936 config BACKTRACE_SELF_TEST
1937 tristate "Self test for the backtrace code"
1938 depends on DEBUG_KERNEL
1940 This option provides a kernel module that can be used to test
1941 the kernel stack backtrace code. This option is not useful
1942 for distributions or general kernels, but only for kernel
1943 developers working on architecture code.
1945 Note that if you want to also test saved backtraces, you will
1946 have to enable STACKTRACE as well.
1948 Say N if you are unsure.
1951 tristate "Red-Black tree test"
1952 depends on DEBUG_KERNEL
1954 A benchmark measuring the performance of the rbtree library.
1955 Also includes rbtree invariant checks.
1957 config REED_SOLOMON_TEST
1958 tristate "Reed-Solomon library test"
1959 depends on DEBUG_KERNEL || m
1961 select REED_SOLOMON_ENC16
1962 select REED_SOLOMON_DEC16
1964 This option enables the self-test function of rslib at boot,
1965 or at module load time.
1969 config INTERVAL_TREE_TEST
1970 tristate "Interval tree test"
1971 depends on DEBUG_KERNEL
1972 select INTERVAL_TREE
1974 A benchmark measuring the performance of the interval tree library
1977 tristate "Per cpu operations test"
1978 depends on m && DEBUG_KERNEL
1980 Enable this option to build test module which validates per-cpu
1985 config ATOMIC64_SELFTEST
1986 tristate "Perform an atomic64_t self-test"
1988 Enable this option to test the atomic64_t functions at boot or
1989 at module load time.
1993 config ASYNC_RAID6_TEST
1994 tristate "Self test for hardware accelerated raid6 recovery"
1995 depends on ASYNC_RAID6_RECOV
1998 This is a one-shot self test that permutes through the
1999 recovery of all the possible two disk failure scenarios for a
2000 N-disk array. Recovery is performed with the asynchronous
2001 raid6 recovery routines, and will optionally use an offload
2002 engine if one is available.
2007 tristate "Test functions located in the hexdump module at runtime"
2009 config TEST_STRING_HELPERS
2010 tristate "Test functions located in the string_helpers module at runtime"
2013 tristate "Test strscpy*() family of functions at runtime"
2016 tristate "Test kstrto*() family of functions at runtime"
2019 tristate "Test printf() family of functions at runtime"
2022 tristate "Test bitmap_*() family of functions at runtime"
2024 Enable this option to test the bitmap functions at boot.
2028 config TEST_BITFIELD
2029 tristate "Test bitfield functions at runtime"
2031 Enable this option to test the bitfield functions at boot.
2036 tristate "Test functions located in the uuid module at runtime"
2039 tristate "Test the XArray code at runtime"
2041 config TEST_OVERFLOW
2042 tristate "Test check_*_overflow() functions at runtime"
2044 config TEST_RHASHTABLE
2045 tristate "Perform selftest on resizable hash table"
2047 Enable this option to test the rhashtable functions at boot.
2052 tristate "Perform selftest on hash functions"
2054 Enable this option to test the kernel's integer (<linux/hash.h>),
2055 string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
2056 hash functions on boot (or module load).
2058 This is intended to help people writing architecture-specific
2059 optimized versions. If unsure, say N.
2062 tristate "Perform selftest on IDA functions"
2065 tristate "Perform selftest on priority array manager"
2068 Enable this option to test priority array manager on boot
2073 config TEST_IRQ_TIMINGS
2074 bool "IRQ timings selftest"
2075 depends on IRQ_TIMINGS
2077 Enable this option to test the irq timings code on boot.
2082 tristate "Test module loading with 'hello world' module"
2085 This builds the "test_module" module that emits "Hello, world"
2086 on printk when loaded. It is designed to be used for basic
2087 evaluation of the module loading subsystem (for example when
2088 validating module verification). It lacks any extra dependencies,
2089 and will not normally be loaded by the system unless explicitly
2095 tristate "Test module for compilation of bitops operations"
2098 This builds the "test_bitops" module that is much like the
2099 TEST_LKM module except that it does a basic exercise of the
2100 set/clear_bit macros and get_count_order/long to make sure there are
2101 no compiler warnings from C=1 sparse checker or -Wextra
2102 compilations. It has no dependencies and doesn't run or load unless
2103 explicitly requested by name. for example: modprobe test_bitops.
2108 tristate "Test module for stress/performance analysis of vmalloc allocator"
2113 This builds the "test_vmalloc" module that should be used for
2114 stress and performance analysis. So, any new change for vmalloc
2115 subsystem can be evaluated from performance and stability point
2120 config TEST_USER_COPY
2121 tristate "Test user/kernel boundary protections"
2124 This builds the "test_user_copy" module that runs sanity checks
2125 on the copy_to/from_user infrastructure, making sure basic
2126 user/kernel boundary testing is working. If it fails to load,
2127 a regression has been detected in the user/kernel memory boundary
2133 tristate "Test BPF filter functionality"
2136 This builds the "test_bpf" module that runs various test vectors
2137 against the BPF interpreter or BPF JIT compiler depending on the
2138 current setting. This is in particular useful for BPF JIT compiler
2139 development, but also to run regression tests against changes in
2140 the interpreter code. It also enables test stubs for eBPF maps and
2141 verifier used by user space verifier testsuite.
2145 config TEST_BLACKHOLE_DEV
2146 tristate "Test blackhole netdev functionality"
2149 This builds the "test_blackhole_dev" module that validates the
2150 data path through this blackhole netdev.
2154 config FIND_BIT_BENCHMARK
2155 tristate "Test find_bit functions"
2157 This builds the "test_find_bit" module that measure find_*_bit()
2158 functions performance.
2162 config TEST_FIRMWARE
2163 tristate "Test firmware loading via userspace interface"
2164 depends on FW_LOADER
2166 This builds the "test_firmware" module that creates a userspace
2167 interface for testing firmware loading. This can be used to
2168 control the triggering of firmware loading without needing an
2169 actual firmware-using device. The contents can be rechecked by
2175 tristate "sysctl test driver"
2176 depends on PROC_SYSCTL
2178 This builds the "test_sysctl" module. This driver enables to test the
2179 proc sysctl interfaces available to drivers safely without affecting
2180 production knobs which might alter system functionality.
2184 config SYSCTL_KUNIT_TEST
2185 tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
2187 default KUNIT_ALL_TESTS
2189 This builds the proc sysctl unit test, which runs on boot.
2190 Tests the API contract and implementation correctness of sysctl.
2191 For more information on KUnit and unit tests in general please refer
2192 to the KUnit documentation in Documentation/dev-tools/kunit/.
2196 config LIST_KUNIT_TEST
2197 tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2199 default KUNIT_ALL_TESTS
2201 This builds the linked list KUnit test suite.
2202 It tests that the API and basic functionality of the list_head type
2203 and associated macros.
2205 KUnit tests run during boot and output the results to the debug log
2206 in TAP format (http://testanything.org/). Only useful for kernel devs
2207 running the KUnit test harness, and not intended for inclusion into a
2210 For more information on KUnit and unit tests in general please refer
2211 to the KUnit documentation in Documentation/dev-tools/kunit/.
2215 config LINEAR_RANGES_TEST
2216 tristate "KUnit test for linear_ranges"
2218 select LINEAR_RANGES
2220 This builds the linear_ranges unit test, which runs on boot.
2221 Tests the linear_ranges logic correctness.
2222 For more information on KUnit and unit tests in general please refer
2223 to the KUnit documentation in Documentation/dev-tools/kunit/.
2228 tristate "udelay test driver"
2230 This builds the "udelay_test" module that helps to make sure
2231 that udelay() is working properly.
2235 config TEST_STATIC_KEYS
2236 tristate "Test static keys"
2239 Test the static key interfaces.
2244 tristate "kmod stress tester"
2246 depends on NETDEVICES && NET_CORE && INET # for TUN
2253 Test the kernel's module loading mechanism: kmod. kmod implements
2254 support to load modules using the Linux kernel's usermode helper.
2255 This test provides a series of tests against kmod.
2257 Although technically you can either build test_kmod as a module or
2258 into the kernel we disallow building it into the kernel since
2259 it stress tests request_module() and this will very likely cause
2260 some issues by taking over precious threads available from other
2261 module load requests, ultimately this could be fatal.
2265 tools/testing/selftests/kmod/kmod.sh --help
2269 config TEST_DEBUG_VIRTUAL
2270 tristate "Test CONFIG_DEBUG_VIRTUAL feature"
2271 depends on DEBUG_VIRTUAL
2273 Test the kernel's ability to detect incorrect calls to
2274 virt_to_phys() done against the non-linear part of the
2275 kernel's virtual address map.
2279 config TEST_MEMCAT_P
2280 tristate "Test memcat_p() helper function"
2282 Test the memcat_p() helper for correctly merging two
2283 pointer arrays together.
2287 config TEST_LIVEPATCH
2288 tristate "Test livepatching"
2290 depends on DYNAMIC_DEBUG
2291 depends on LIVEPATCH
2294 Test kernel livepatching features for correctness. The tests will
2295 load test modules that will be livepatched in various scenarios.
2297 To run all the livepatching tests:
2299 make -C tools/testing/selftests TARGETS=livepatch run_tests
2301 Alternatively, individual tests may be invoked:
2303 tools/testing/selftests/livepatch/test-callbacks.sh
2304 tools/testing/selftests/livepatch/test-livepatch.sh
2305 tools/testing/selftests/livepatch/test-shadow-vars.sh
2310 tristate "Perform selftest on object aggreration manager"
2314 Enable this option to test object aggregation manager on boot
2318 config TEST_STACKINIT
2319 tristate "Test level of stack variable initialization"
2321 Test if the kernel is zero-initializing stack variables and
2322 padding. Coverage is controlled by compiler flags,
2323 CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
2324 or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
2329 tristate "Test heap/page initialization"
2331 Test if the kernel is zero-initializing heap and page allocations.
2332 This can be useful to test init_on_alloc and init_on_free features.
2337 tristate "Test HMM (Heterogeneous Memory Management)"
2338 depends on TRANSPARENT_HUGEPAGE
2339 depends on DEVICE_PRIVATE
2343 This is a pseudo device driver solely for testing HMM.
2344 Say M here if you want to build the HMM test module.
2345 Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2350 tristate "Test floating point operations in kernel space"
2351 depends on X86 && !KCOV_INSTRUMENT_ALL
2353 Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
2354 which will trigger a sequence of floating point operations. This is used
2355 for self-testing floating point control register setting in
2360 endif # RUNTIME_TESTING_MENU
2365 This option adds a kernel parameter 'memtest', which allows memtest
2367 memtest=0, mean disabled; -- default
2368 memtest=1, mean do 1 test pattern;
2370 memtest=17, mean do 17 test patterns.
2371 If you are unsure how to answer this question, answer N.
2375 config HYPERV_TESTING
2376 bool "Microsoft Hyper-V driver testing"
2378 depends on HYPERV && DEBUG_FS
2380 Select this option to enable Hyper-V vmbus testing.
2382 endmenu # "Kernel Testing and Coverage"
2384 endmenu # Kernel hacking