TOMOYO Linux Cross Reference
Linux/lib/Kconfig.debug

   # SPDX-License-Identifier: GPL-2.0-only
   menu "Kernel hacking"
   
   menu "printk and dmesg options"
   
   config PRINTK_TIME
           bool "Show timing information on printks"
           depends on PRINTK
           help
            Selecting this option causes time stamps of the printk()
            messages to be added to the output of the syslog() system
            call and at the console.
  
            The timestamp is always recorded internally, and exported
            to /dev/kmsg. This flag just specifies if the timestamp should
            be included, not that the timestamp is recorded.
  
            The behavior is also controlled by the kernel command line
            parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
  
  config PRINTK_CALLER
          bool "Show caller information on printks"
          depends on PRINTK
          help
            Selecting this option causes printk() to add a caller "thread id" (if
            in task context) or a caller "processor id" (if not in task context)
            to every message.
  
            This option is intended for environments where multiple threads
            concurrently call printk() for many times, for it is difficult to
            interpret without knowing where these lines (or sometimes individual
            line which was divided into multiple lines due to race) came from.
  
            Since toggling after boot makes the code racy, currently there is
            no option to enable/disable at the kernel command line parameter or
            sysfs interface.
  
  config STACKTRACE_BUILD_ID
          bool "Show build ID information in stacktraces"
          depends on PRINTK
          help
            Selecting this option adds build ID information for symbols in
            stacktraces printed with the printk format '%p[SR]b'.
  
            This option is intended for distros where debuginfo is not easily
            accessible but can be downloaded given the build ID of the vmlinux or
            kernel module where the function is located.
  
  config CONSOLE_LOGLEVEL_DEFAULT
          int "Default console loglevel (1-15)"
          range 1 15
          default "7"
          help
            Default loglevel to determine what will be printed on the console.
  
            Setting a default here is equivalent to passing in loglevel=<x> in
            the kernel bootargs. loglevel=<x> continues to override whatever
            value is specified here as well.
  
            Note: This does not affect the log level of un-prefixed printk()
            usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
            option.
  
  config CONSOLE_LOGLEVEL_QUIET
          int "quiet console loglevel (1-15)"
          range 1 15
          default "4"
          help
            loglevel to use when "quiet" is passed on the kernel commandline.
  
            When "quiet" is passed on the kernel commandline this loglevel
            will be used as the loglevel. IOW passing "quiet" will be the
            equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
  
  config MESSAGE_LOGLEVEL_DEFAULT
          int "Default message log level (1-7)"
          range 1 7
          default "4"
          help
            Default log level for printk statements with no specified priority.
  
            This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
            that are auditing their logs closely may want to set it to a lower
            priority.
  
            Note: This does not affect what message level gets printed on the console
            by default. To change that, use loglevel=<x> in the kernel bootargs,
            or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
  
  config BOOT_PRINTK_DELAY
          bool "Delay each boot printk message by N milliseconds"
          depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
          help
            This build option allows you to read kernel boot messages
            by inserting a short delay after each one.  The delay is
            specified in milliseconds on the kernel command line,
            using "boot_delay=N".
  
            It is likely that you would also need to use "lpj=M" to preset
           the "loops per jiffie" value.
           See a previous boot log for the "lpj" value to use for your
           system, and then set "lpj=M" before setting "boot_delay=N".
           NOTE:  Using this option may adversely affect SMP systems.
           I.e., processors other than the first one may not boot up.
           BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
           what it believes to be lockup conditions.
 
 config DYNAMIC_DEBUG
         bool "Enable dynamic printk() support"
         default n
         depends on PRINTK
         depends on (DEBUG_FS || PROC_FS)
         select DYNAMIC_DEBUG_CORE
         help
 
           Compiles debug level messages into the kernel, which would not
           otherwise be available at runtime. These messages can then be
           enabled/disabled based on various levels of scope - per source file,
           function, module, format string, and line number. This mechanism
           implicitly compiles in all pr_debug() and dev_dbg() calls, which
           enlarges the kernel text size by about 2%.
 
           If a source file is compiled with DEBUG flag set, any
           pr_debug() calls in it are enabled by default, but can be
           disabled at runtime as below.  Note that DEBUG flag is
           turned on by many CONFIG_*DEBUG* options.
 
           Usage:
 
           Dynamic debugging is controlled via the 'dynamic_debug/control' file,
           which is contained in the 'debugfs' filesystem or procfs.
           Thus, the debugfs or procfs filesystem must first be mounted before
           making use of this feature.
           We refer the control file as: <debugfs>/dynamic_debug/control. This
           file contains a list of the debug statements that can be enabled. The
           format for each line of the file is:
 
                 filename:lineno [module]function flags format
 
           filename : source file of the debug statement
           lineno : line number of the debug statement
           module : module that contains the debug statement
           function : function that contains the debug statement
           flags : '=p' means the line is turned 'on' for printing
           format : the format used for the debug statement
 
           From a live system:
 
                 nullarbor:~ # cat <debugfs>/dynamic_debug/control
                 # filename:lineno [module]function flags format
                 fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
                 fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
                 fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
 
           Example usage:
 
                 // enable the message at line 1603 of file svcsock.c
                 nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
                                                 <debugfs>/dynamic_debug/control
 
                 // enable all the messages in file svcsock.c
                 nullarbor:~ # echo -n 'file svcsock.c +p' >
                                                 <debugfs>/dynamic_debug/control
 
                 // enable all the messages in the NFS server module
                 nullarbor:~ # echo -n 'module nfsd +p' >
                                                 <debugfs>/dynamic_debug/control
 
                 // enable all 12 messages in the function svc_process()
                 nullarbor:~ # echo -n 'func svc_process +p' >
                                                 <debugfs>/dynamic_debug/control
 
                 // disable all 12 messages in the function svc_process()
                 nullarbor:~ # echo -n 'func svc_process -p' >
                                                 <debugfs>/dynamic_debug/control
 
           See Documentation/admin-guide/dynamic-debug-howto.rst for additional
           information.
 
 config DYNAMIC_DEBUG_CORE
         bool "Enable core function of dynamic debug support"
         depends on PRINTK
         depends on (DEBUG_FS || PROC_FS)
         help
           Enable core functional support of dynamic debug. It is useful
           when you want to tie dynamic debug to your kernel modules with
           DYNAMIC_DEBUG_MODULE defined for each of them, especially for
           the case of embedded system where the kernel image size is
           sensitive for people.
 
 config SYMBOLIC_ERRNAME
         bool "Support symbolic error names in printf"
         default y if PRINTK
         help
           If you say Y here, the kernel's printf implementation will
           be able to print symbolic error names such as ENOSPC instead
           of the number 28. It makes the kernel image slightly larger
           (about 3KB), but can make the kernel logs easier to read.
 
 config DEBUG_BUGVERBOSE
         bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
         depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
         default y
         help
           Say Y here to make BUG() panics output the file name and line number
           of the BUG call as well as the EIP and oops trace.  This aids
           debugging but costs about 70-100K of memory.
 
 endmenu # "printk and dmesg options"
 
 config DEBUG_KERNEL
         bool "Kernel debugging"
         help
           Say Y here if you are developing drivers or trying to debug and
           identify kernel problems.
 
 config DEBUG_MISC
         bool "Miscellaneous debug code"
         default DEBUG_KERNEL
         depends on DEBUG_KERNEL
         help
           Say Y here if you need to enable miscellaneous debug code that should
           be under a more specific debug option but isn't.
 
 menu "Compile-time checks and compiler options"
 
 config DEBUG_INFO
         bool
         help
           A kernel debug info option other than "None" has been selected
           in the "Debug information" choice below, indicating that debug
           information will be generated for build targets.
 
 # Clang generates .uleb128 with label differences for DWARF v5, a feature that
 # older binutils ports do not support when utilizing RISC-V style linker
 # relaxation: https://sourceware.org/bugzilla/show_bug.cgi?id=27215
 config AS_HAS_NON_CONST_ULEB128
         def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
 
 choice
         prompt "Debug information"
         depends on DEBUG_KERNEL
         help
           Selecting something other than "None" results in a kernel image
           that will include debugging info resulting in a larger kernel image.
           This adds debug symbols to the kernel and modules (gcc -g), and
           is needed if you intend to use kernel crashdump or binary object
           tools like crash, kgdb, LKCD, gdb, etc on the kernel.
 
           Choose which version of DWARF debug info to emit. If unsure,
           select "Toolchain default".
 
 config DEBUG_INFO_NONE
         bool "Disable debug information"
         help
           Do not build the kernel with debugging information, which will
           result in a faster and smaller build.
 
 config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
         bool "Rely on the toolchain's implicit default DWARF version"
         select DEBUG_INFO
         depends on !CC_IS_CLANG || AS_IS_LLVM || CLANG_VERSION < 140000 || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
         help
           The implicit default version of DWARF debug info produced by a
           toolchain changes over time.
 
           This can break consumers of the debug info that haven't upgraded to
           support newer revisions, and prevent testing newer versions, but
           those should be less common scenarios.
 
 config DEBUG_INFO_DWARF4
         bool "Generate DWARF Version 4 debuginfo"
         select DEBUG_INFO
         depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502)
         help
           Generate DWARF v4 debug info. This requires gcc 4.5+, binutils 2.35.2
           if using clang without clang's integrated assembler, and gdb 7.0+.
 
           If you have consumers of DWARF debug info that are not ready for
           newer revisions of DWARF, you may wish to choose this or have your
           config select this.
 
 config DEBUG_INFO_DWARF5
         bool "Generate DWARF Version 5 debuginfo"
         select DEBUG_INFO
         depends on !ARCH_HAS_BROKEN_DWARF5
         depends on !CC_IS_CLANG || AS_IS_LLVM || (AS_IS_GNU && AS_VERSION >= 23502 && AS_HAS_NON_CONST_ULEB128)
         help
           Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
           5.0+ accepts the -gdwarf-5 flag but only had partial support for some
           draft features until 7.0), and gdb 8.0+.
 
           Changes to the structure of debug info in Version 5 allow for around
           15-18% savings in resulting image and debug info section sizes as
           compared to DWARF Version 4. DWARF Version 5 standardizes previous
           extensions such as accelerators for symbol indexing and the format
           for fission (.dwo/.dwp) files. Users may not want to select this
           config if they rely on tooling that has not yet been updated to
           support DWARF Version 5.
 
 endchoice # "Debug information"
 
 if DEBUG_INFO
 
 config DEBUG_INFO_REDUCED
         bool "Reduce debugging information"
         help
           If you say Y here gcc is instructed to generate less debugging
           information for structure types. This means that tools that
           need full debugging information (like kgdb or systemtap) won't
           be happy. But if you merely need debugging information to
           resolve line numbers there is no loss. Advantage is that
           build directory object sizes shrink dramatically over a full
           DEBUG_INFO build and compile times are reduced too.
           Only works with newer gcc versions.
 
 choice
         prompt "Compressed Debug information"
         help
           Compress the resulting debug info. Results in smaller debug info sections,
           but requires that consumers are able to decompress the results.
 
           If unsure, choose DEBUG_INFO_COMPRESSED_NONE.
 
 config DEBUG_INFO_COMPRESSED_NONE
         bool "Don't compress debug information"
         help
           Don't compress debug info sections.
 
 config DEBUG_INFO_COMPRESSED_ZLIB
         bool "Compress debugging information with zlib"
         depends on $(cc-option,-gz=zlib)
         depends on $(ld-option,--compress-debug-sections=zlib)
         help
           Compress the debug information using zlib.  Requires GCC 5.0+ or Clang
           5.0+, binutils 2.26+, and zlib.
 
           Users of dpkg-deb via scripts/package/builddeb may find an increase in
           size of their debug .deb packages with this config set, due to the
           debug info being compressed with zlib, then the object files being
           recompressed with a different compression scheme. But this is still
           preferable to setting $KDEB_COMPRESS to "none" which would be even
           larger.
 
 config DEBUG_INFO_COMPRESSED_ZSTD
         bool "Compress debugging information with zstd"
         depends on $(cc-option,-gz=zstd)
         depends on $(ld-option,--compress-debug-sections=zstd)
         help
           Compress the debug information using zstd.  This may provide better
           compression than zlib, for about the same time costs, but requires newer
           toolchain support.  Requires GCC 13.0+ or Clang 16.0+, binutils 2.40+, and
           zstd.
 
 endchoice # "Compressed Debug information"
 
 config DEBUG_INFO_SPLIT
         bool "Produce split debuginfo in .dwo files"
         depends on $(cc-option,-gsplit-dwarf)
         # RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
         # prior to 12.x:
         # https://github.com/llvm/llvm-project/issues/56642
         # https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99090
         depends on !RISCV || GCC_VERSION >= 120000
         help
           Generate debug info into separate .dwo files. This significantly
           reduces the build directory size for builds with DEBUG_INFO,
           because it stores the information only once on disk in .dwo
           files instead of multiple times in object files and executables.
           In addition the debug information is also compressed.
 
           Requires recent gcc (4.7+) and recent gdb/binutils.
           Any tool that packages or reads debug information would need
           to know about the .dwo files and include them.
           Incompatible with older versions of ccache.
 
 config DEBUG_INFO_BTF
         bool "Generate BTF type information"
         depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
         depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
         depends on BPF_SYSCALL
         depends on !DEBUG_INFO_DWARF5 || PAHOLE_VERSION >= 121
         # pahole uses elfutils, which does not have support for Hexagon relocations
         depends on !HEXAGON
         help
           Generate deduplicated BTF type information from DWARF debug info.
           Turning this on expects presence of pahole tool, which will convert
           DWARF type info into equivalent deduplicated BTF type info.
 
 config PAHOLE_HAS_SPLIT_BTF
         def_bool PAHOLE_VERSION >= 119
 
 config PAHOLE_HAS_BTF_TAG
         def_bool PAHOLE_VERSION >= 123
         depends on CC_IS_CLANG
         help
           Decide whether pahole emits btf_tag attributes (btf_type_tag and
           btf_decl_tag) or not. Currently only clang compiler implements
           these attributes, so make the config depend on CC_IS_CLANG.
 
 config PAHOLE_HAS_LANG_EXCLUDE
         def_bool PAHOLE_VERSION >= 124
         help
           Support for the --lang_exclude flag which makes pahole exclude
           compilation units from the supplied language. Used in Kbuild to
           omit Rust CUs which are not supported in version 1.24 of pahole,
           otherwise it would emit malformed kernel and module binaries when
           using DEBUG_INFO_BTF_MODULES.
 
 config DEBUG_INFO_BTF_MODULES
         bool "Generate BTF type information for kernel modules"
         default y
         depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
         help
           Generate compact split BTF type information for kernel modules.
 
 config MODULE_ALLOW_BTF_MISMATCH
         bool "Allow loading modules with non-matching BTF type info"
         depends on DEBUG_INFO_BTF_MODULES
         help
           For modules whose split BTF does not match vmlinux, load without
           BTF rather than refusing to load. The default behavior with
           module BTF enabled is to reject modules with such mismatches;
           this option will still load module BTF where possible but ignore
           it when a mismatch is found.
 
 config GDB_SCRIPTS
         bool "Provide GDB scripts for kernel debugging"
         help
           This creates the required links to GDB helper scripts in the
           build directory. If you load vmlinux into gdb, the helper
           scripts will be automatically imported by gdb as well, and
           additional functions are available to analyze a Linux kernel
           instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
           for further details.
 
 endif # DEBUG_INFO
 
 config FRAME_WARN
         int "Warn for stack frames larger than"
         range 0 8192
         default 0 if KMSAN
         default 2048 if GCC_PLUGIN_LATENT_ENTROPY
         default 2048 if PARISC
         default 1536 if (!64BIT && XTENSA)
         default 1280 if KASAN && !64BIT
         default 1024 if !64BIT
         default 2048 if 64BIT
         help
           Tell the compiler to warn at build time for stack frames larger than this.
           Setting this too low will cause a lot of warnings.
           Setting it to 0 disables the warning.
 
 config STRIP_ASM_SYMS
         bool "Strip assembler-generated symbols during link"
         default n
         help
           Strip internal assembler-generated symbols during a link (symbols
           that look like '.Lxxx') so they don't pollute the output of
           get_wchan() and suchlike.
 
 config READABLE_ASM
         bool "Generate readable assembler code"
         depends on DEBUG_KERNEL
         depends on CC_IS_GCC
         help
           Disable some compiler optimizations that tend to generate human unreadable
           assembler output. This may make the kernel slightly slower, but it helps
           to keep kernel developers who have to stare a lot at assembler listings
           sane.
 
 config HEADERS_INSTALL
         bool "Install uapi headers to usr/include"
         depends on !UML
         help
           This option will install uapi headers (headers exported to user-space)
           into the usr/include directory for use during the kernel build.
           This is unneeded for building the kernel itself, but needed for some
           user-space program samples. It is also needed by some features such
           as uapi header sanity checks.
 
 config DEBUG_SECTION_MISMATCH
         bool "Enable full Section mismatch analysis"
         depends on CC_IS_GCC
         help
           The section mismatch analysis checks if there are illegal
           references from one section to another section.
           During linktime or runtime, some sections are dropped;
           any use of code/data previously in these sections would
           most likely result in an oops.
           In the code, functions and variables are annotated with
           __init,, etc. (see the full list in include/linux/init.h),
           which results in the code/data being placed in specific sections.
           The section mismatch analysis is always performed after a full
           kernel build, and enabling this option causes the following
           additional step to occur:
           - Add the option -fno-inline-functions-called-once to gcc commands.
             When inlining a function annotated with __init in a non-init
             function, we would lose the section information and thus
             the analysis would not catch the illegal reference.
             This option tells gcc to inline less (but it does result in
             a larger kernel).
 
 config SECTION_MISMATCH_WARN_ONLY
         bool "Make section mismatch errors non-fatal"
         default y
         help
           If you say N here, the build process will fail if there are any
           section mismatch, instead of just throwing warnings.
 
           If unsure, say Y.
 
 config DEBUG_FORCE_FUNCTION_ALIGN_64B
         bool "Force all function address 64B aligned"
         depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || RISCV || S390)
         select FUNCTION_ALIGNMENT_64B
         help
           There are cases that a commit from one domain changes the function
           address alignment of other domains, and cause magic performance
           bump (regression or improvement). Enable this option will help to
           verify if the bump is caused by function alignment changes, while
           it will slightly increase the kernel size and affect icache usage.
 
           It is mainly for debug and performance tuning use.
 
 #
 # Select this config option from the architecture Kconfig, if it
 # is preferred to always offer frame pointers as a config
 # option on the architecture (regardless of KERNEL_DEBUG):
 #
 config ARCH_WANT_FRAME_POINTERS
         bool
 
 config FRAME_POINTER
         bool "Compile the kernel with frame pointers"
         depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || ARCH_WANT_FRAME_POINTERS
         default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
         help
           If you say Y here the resulting kernel image will be slightly
           larger and slower, but it gives very useful debugging information
           in case of kernel bugs. (precise oopses/stacktraces/warnings)
 
 config OBJTOOL
         bool
 
 config STACK_VALIDATION
         bool "Compile-time stack metadata validation"
         depends on HAVE_STACK_VALIDATION && UNWINDER_FRAME_POINTER
         select OBJTOOL
         default n
         help
           Validate frame pointer rules at compile-time.  This helps ensure that
           runtime stack traces are more reliable.
 
           For more information, see
           tools/objtool/Documentation/objtool.txt.
 
 config NOINSTR_VALIDATION
         bool
         depends on HAVE_NOINSTR_VALIDATION && DEBUG_ENTRY
         select OBJTOOL
         default y
 
 config VMLINUX_MAP
         bool "Generate vmlinux.map file when linking"
         depends on EXPERT
         help
           Selecting this option will pass "-Map=vmlinux.map" to ld
           when linking vmlinux. That file can be useful for verifying
           and debugging magic section games, and for seeing which
           pieces of code get eliminated with
           CONFIG_LD_DEAD_CODE_DATA_ELIMINATION.
 
 config DEBUG_FORCE_WEAK_PER_CPU
         bool "Force weak per-cpu definitions"
         depends on DEBUG_KERNEL
         help
           s390 and alpha require percpu variables in modules to be
           defined weak to work around addressing range issue which
           puts the following two restrictions on percpu variable
           definitions.
 
           1. percpu symbols must be unique whether static or not
           2. percpu variables can't be defined inside a function
 
           To ensure that generic code follows the above rules, this
           option forces all percpu variables to be defined as weak.
 
 endmenu # "Compiler options"
 
 menu "Generic Kernel Debugging Instruments"
 
 config MAGIC_SYSRQ
         bool "Magic SysRq key"
         depends on !UML
         help
           If you say Y here, you will have some control over the system even
           if the system crashes for example during kernel debugging (e.g., you
           will be able to flush the buffer cache to disk, reboot the system
           immediately or dump some status information). This is accomplished
           by pressing various keys while holding SysRq (Alt+PrintScreen). It
           also works on a serial console (on PC hardware at least), if you
           send a BREAK and then within 5 seconds a command keypress. The
           keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
           Don't say Y unless you really know what this hack does.
 
 config MAGIC_SYSRQ_DEFAULT_ENABLE
         hex "Enable magic SysRq key functions by default"
         depends on MAGIC_SYSRQ
         default 0x1
         help
           Specifies which SysRq key functions are enabled by default.
           This may be set to 1 or 0 to enable or disable them all, or
           to a bitmask as described in Documentation/admin-guide/sysrq.rst.
 
 config MAGIC_SYSRQ_SERIAL
         bool "Enable magic SysRq key over serial"
         depends on MAGIC_SYSRQ
         default y
         help
           Many embedded boards have a disconnected TTL level serial which can
           generate some garbage that can lead to spurious false sysrq detects.
           This option allows you to decide whether you want to enable the
           magic SysRq key.
 
 config MAGIC_SYSRQ_SERIAL_SEQUENCE
         string "Char sequence that enables magic SysRq over serial"
         depends on MAGIC_SYSRQ_SERIAL
         default ""
         help
           Specifies a sequence of characters that can follow BREAK to enable
           SysRq on a serial console.
 
           If unsure, leave an empty string and the option will not be enabled.
 
 config DEBUG_FS
         bool "Debug Filesystem"
         help
           debugfs is a virtual file system that kernel developers use to put
           debugging files into.  Enable this option to be able to read and
           write to these files.
 
           For detailed documentation on the debugfs API, see
           Documentation/filesystems/.
 
           If unsure, say N.
 
 choice
         prompt "Debugfs default access"
         depends on DEBUG_FS
         default DEBUG_FS_ALLOW_ALL
         help
           This selects the default access restrictions for debugfs.
           It can be overridden with kernel command line option
           debugfs=[on,no-mount,off]. The restrictions apply for API access
           and filesystem registration.
 
 config DEBUG_FS_ALLOW_ALL
         bool "Access normal"
         help
           No restrictions apply. Both API and filesystem registration
           is on. This is the normal default operation.
 
 config DEBUG_FS_DISALLOW_MOUNT
         bool "Do not register debugfs as filesystem"
         help
           The API is open but filesystem is not loaded. Clients can still do
           their work and read with debug tools that do not need
           debugfs filesystem.
 
 config DEBUG_FS_ALLOW_NONE
         bool "No access"
         help
           Access is off. Clients get -PERM when trying to create nodes in
           debugfs tree and debugfs is not registered as a filesystem.
           Client can then back-off or continue without debugfs access.
 
 endchoice
 
 source "lib/Kconfig.kgdb"
 source "lib/Kconfig.ubsan"
 source "lib/Kconfig.kcsan"
 
 endmenu
 
 menu "Networking Debugging"
 
 source "net/Kconfig.debug"
 
 endmenu # "Networking Debugging"
 
 menu "Memory Debugging"
 
 source "mm/Kconfig.debug"
 
 config DEBUG_OBJECTS
         bool "Debug object operations"
         depends on DEBUG_KERNEL
         help
           If you say Y here, additional code will be inserted into the
           kernel to track the life time of various objects and validate
           the operations on those objects.
 
 config DEBUG_OBJECTS_SELFTEST
         bool "Debug objects selftest"
         depends on DEBUG_OBJECTS
         help
           This enables the selftest of the object debug code.
 
 config DEBUG_OBJECTS_FREE
         bool "Debug objects in freed memory"
         depends on DEBUG_OBJECTS
         help
           This enables checks whether a k/v free operation frees an area
           which contains an object which has not been deactivated
           properly. This can make kmalloc/kfree-intensive workloads
           much slower.
 
 config DEBUG_OBJECTS_TIMERS
         bool "Debug timer objects"
         depends on DEBUG_OBJECTS
         help
           If you say Y here, additional code will be inserted into the
           timer routines to track the life time of timer objects and
           validate the timer operations.
 
 config DEBUG_OBJECTS_WORK
         bool "Debug work objects"
         depends on DEBUG_OBJECTS
         help
           If you say Y here, additional code will be inserted into the
           work queue routines to track the life time of work objects and
           validate the work operations.
 
 config DEBUG_OBJECTS_RCU_HEAD
         bool "Debug RCU callbacks objects"
         depends on DEBUG_OBJECTS
         help
           Enable this to turn on debugging of RCU list heads (call_rcu() usage).
 
 config DEBUG_OBJECTS_PERCPU_COUNTER
         bool "Debug percpu counter objects"
         depends on DEBUG_OBJECTS
         help
           If you say Y here, additional code will be inserted into the
           percpu counter routines to track the life time of percpu counter
           objects and validate the percpu counter operations.
 
 config DEBUG_OBJECTS_ENABLE_DEFAULT
         int "debug_objects bootup default value (0-1)"
         range 0 1
         default "1"
         depends on DEBUG_OBJECTS
         help
           Debug objects boot parameter default value
 
 config SHRINKER_DEBUG
         bool "Enable shrinker debugging support"
         depends on DEBUG_FS
         help
           Say Y to enable the shrinker debugfs interface which provides
           visibility into the kernel memory shrinkers subsystem.
           Disable it to avoid an extra memory footprint.
 
 config DEBUG_STACK_USAGE
         bool "Stack utilization instrumentation"
         depends on DEBUG_KERNEL
         help
           Enables the display of the minimum amount of free stack which each
           task has ever had available in the sysrq-T and sysrq-P debug output.
           Also emits a message to dmesg when a process exits if that process
           used more stack space than previously exiting processes.
 
           This option will slow down process creation somewhat.
 
 config SCHED_STACK_END_CHECK
         bool "Detect stack corruption on calls to schedule()"
         depends on DEBUG_KERNEL
         default n
         help
           This option checks for a stack overrun on calls to schedule().
           If the stack end location is found to be over written always panic as
           the content of the corrupted region can no longer be trusted.
           This is to ensure no erroneous behaviour occurs which could result in
           data corruption or a sporadic crash at a later stage once the region
           is examined. The runtime overhead introduced is minimal.
 
 config ARCH_HAS_DEBUG_VM_PGTABLE
         bool
         help
           An architecture should select this when it can successfully
           build and run DEBUG_VM_PGTABLE.
 
 config DEBUG_VM_IRQSOFF
         def_bool DEBUG_VM && !PREEMPT_RT
 
 config DEBUG_VM
         bool "Debug VM"
         depends on DEBUG_KERNEL
         help
           Enable this to turn on extended checks in the virtual-memory system
           that may impact performance.
 
           If unsure, say N.
 
 config DEBUG_VM_SHOOT_LAZIES
         bool "Debug MMU_LAZY_TLB_SHOOTDOWN implementation"
         depends on DEBUG_VM
         depends on MMU_LAZY_TLB_SHOOTDOWN
         help
           Enable additional IPIs that ensure lazy tlb mm references are removed
           before the mm is freed.
 
           If unsure, say N.
 
 config DEBUG_VM_MAPLE_TREE
         bool "Debug VM maple trees"
         depends on DEBUG_VM
         select DEBUG_MAPLE_TREE
         help
           Enable VM maple tree debugging information and extra validations.
 
           If unsure, say N.
 
 config DEBUG_VM_RB
         bool "Debug VM red-black trees"
         depends on DEBUG_VM
         help
           Enable VM red-black tree debugging information and extra validations.
 
           If unsure, say N.
 
 config DEBUG_VM_PGFLAGS
         bool "Debug page-flags operations"
         depends on DEBUG_VM
         help
           Enables extra validation on page flags operations.
 
           If unsure, say N.
 
 config DEBUG_VM_PGTABLE
         bool "Debug arch page table for semantics compliance"
         depends on MMU
         depends on ARCH_HAS_DEBUG_VM_PGTABLE
         default y if DEBUG_VM
         help
           This option provides a debug method which can be used to test
           architecture page table helper functions on various platforms in
           verifying if they comply with expected generic MM semantics. This
           will help architecture code in making sure that any changes or
           new additions of these helpers still conform to expected
           semantics of the generic MM. Platforms will have to opt in for
           this through ARCH_HAS_DEBUG_VM_PGTABLE.
 
           If unsure, say N.
 
 config ARCH_HAS_DEBUG_VIRTUAL
         bool
 
 config DEBUG_VIRTUAL
         bool "Debug VM translations"
         depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
         help
           Enable some costly sanity checks in virtual to page code. This can
           catch mistakes with virt_to_page() and friends.
 
           If unsure, say N.
 
 config DEBUG_NOMMU_REGIONS
         bool "Debug the global anon/private NOMMU mapping region tree"
         depends on DEBUG_KERNEL && !MMU
         help
           This option causes the global tree of anonymous and private mapping
           regions to be regularly checked for invalid topology.
 
 config DEBUG_MEMORY_INIT
         bool "Debug memory initialisation" if EXPERT
         default !EXPERT
         help
           Enable this for additional checks during memory initialisation.
           The sanity checks verify aspects of the VM such as the memory model
           and other information provided by the architecture. Verbose
           information will be printed at KERN_DEBUG loglevel depending
           on the mminit_loglevel= command-line option.
 
           If unsure, say Y
 
 config MEMORY_NOTIFIER_ERROR_INJECT
         tristate "Memory hotplug notifier error injection module"
         depends on MEMORY_HOTPLUG && NOTIFIER_ERROR_INJECTION
         help
           This option provides the ability to inject artificial errors to
           memory hotplug notifier chain callbacks.  It is controlled through
           debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
 
           If the notifier call chain should be failed with some events
           notified, write the error code to "actions/<notifier event>/error".
 
           Example: Inject memory hotplug offline error (-12 == -ENOMEM)
 
           # cd /sys/kernel/debug/notifier-error-inject/memory
           # echo -12 > actions/MEM_GOING_OFFLINE/error
           # echo offline > /sys/devices/system/memory/memoryXXX/state
           bash: echo: write error: Cannot allocate memory
 
           To compile this code as a module, choose M here: the module will
           be called memory-notifier-error-inject.
 
           If unsure, say N.
 
 config DEBUG_PER_CPU_MAPS
         bool "Debug access to per_cpu maps"
         depends on DEBUG_KERNEL
         depends on SMP
         help
           Say Y to verify that the per_cpu map being accessed has
           been set up. This adds a fair amount of code to kernel memory
           and decreases performance.
 
           Say N if unsure.
 
 config DEBUG_KMAP_LOCAL
         bool "Debug kmap_local temporary mappings"
         depends on DEBUG_KERNEL && KMAP_LOCAL
         help
           This option enables additional error checking for the kmap_local
           infrastructure.  Disable for production use.
 
 config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
         bool
 
 config DEBUG_KMAP_LOCAL_FORCE_MAP
         bool "Enforce kmap_local temporary mappings"
         depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
         select KMAP_LOCAL
         select DEBUG_KMAP_LOCAL
         help
           This option enforces temporary mappings through the kmap_local
           mechanism for non-highmem pages and on non-highmem systems.
           Disable this for production systems!
 
 config DEBUG_HIGHMEM
         bool "Highmem debugging"
         depends on DEBUG_KERNEL && HIGHMEM
         select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
         select DEBUG_KMAP_LOCAL
         help
           This option enables additional error checking for high memory
           systems.  Disable for production systems.
 
 config HAVE_DEBUG_STACKOVERFLOW
         bool
 
 config DEBUG_STACKOVERFLOW
         bool "Check for stack overflows"
         depends on DEBUG_KERNEL && HAVE_DEBUG_STACKOVERFLOW
         help
           Say Y here if you want to check for overflows of kernel, IRQ
           and exception stacks (if your architecture uses them). This
           option will show detailed messages if free stack space drops
           below a certain limit.
 
           These kinds of bugs usually occur when call-chains in the
           kernel get too deep, especially when interrupts are
           involved.
 
           Use this in cases where you see apparently random memory
           corruption, especially if it appears in 'struct thread_info'
 
           If in doubt, say "N".
 
 config CODE_TAGGING
         bool
         select KALLSYMS
 
 config MEM_ALLOC_PROFILING
         bool "Enable memory allocation profiling"
         default n
         depends on PROC_FS
         depends on !DEBUG_FORCE_WEAK_PER_CPU
         select CODE_TAGGING
         select PAGE_EXTENSION
         select SLAB_OBJ_EXT
         help
           Track allocation source code and record total allocation size
           initiated at that code location. The mechanism can be used to track
           memory leaks with a low performance and memory impact.
 
 config MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
         bool "Enable memory allocation profiling by default"
         default y
         depends on MEM_ALLOC_PROFILING
 
 config MEM_ALLOC_PROFILING_DEBUG
         bool "Memory allocation profiler debugging"
         default n
         depends on MEM_ALLOC_PROFILING
         select MEM_ALLOC_PROFILING_ENABLED_BY_DEFAULT
         help
           Adds warnings with helpful error messages for memory allocation
           profiling.
 
 source "lib/Kconfig.kasan"
 source "lib/Kconfig.kfence"
 source "lib/Kconfig.kmsan"
 
 endmenu # "Memory Debugging"
 
 config DEBUG_SHIRQ
         bool "Debug shared IRQ handlers"
         depends on DEBUG_KERNEL
         help
           Enable this to generate a spurious interrupt just before a shared
           interrupt handler is deregistered (generating one when registering
           is currently disabled). Drivers need to handle this correctly. Some
           don't and need to be caught.
 
 menu "Debug Oops, Lockups and Hangs"
 
 config PANIC_ON_OOPS
         bool "Panic on Oops"
         help
           Say Y here to enable the kernel to panic when it oopses. This
           has the same effect as setting oops=panic on the kernel command
           line.
 
           This feature is useful to ensure that the kernel does not do
           anything erroneous after an oops which could result in data
           corruption or other issues.
 
           Say N if unsure.
 
 config PANIC_ON_OOPS_VALUE
         int
         range 0 1
         default 0 if !PANIC_ON_OOPS
         default 1 if PANIC_ON_OOPS
 
 config PANIC_TIMEOUT
         int "panic timeout"
         default 0
         help
           Set the timeout value (in seconds) until a reboot occurs when
           the kernel panics. If n = 0, then we wait forever. A timeout
           value n > 0 will wait n seconds before rebooting, while a timeout
           value n < 0 will reboot immediately. This setting can be overridden
           with the kernel command line option panic=, and from userspace via
           /proc/sys/kernel/panic.
 
 config LOCKUP_DETECTOR
         bool
 
 config SOFTLOCKUP_DETECTOR
         bool "Detect Soft Lockups"
         depends on DEBUG_KERNEL && !S390
         select LOCKUP_DETECTOR
         help
           Say Y here to enable the kernel to act as a watchdog to detect
           soft lockups.
 
           Softlockups are bugs that cause the kernel to loop in kernel
           mode for more than 20 seconds, without giving other tasks a
           chance to run.  The current stack trace is displayed upon
           detection and the system will stay locked up.
 
 config SOFTLOCKUP_DETECTOR_INTR_STORM
         bool "Detect Interrupt Storm in Soft Lockups"
         depends on SOFTLOCKUP_DETECTOR && IRQ_TIME_ACCOUNTING
         select GENERIC_IRQ_STAT_SNAPSHOT
         default y if NR_CPUS <= 128
         help
           Say Y here to enable the kernel to detect interrupt storm
           during "soft lockups".
 
           "soft lockups" can be caused by a variety of reasons. If one is
           caused by an interrupt storm, then the storming interrupts will not
           be on the callstack. To detect this case, it is necessary to report
           the CPU stats and the interrupt counts during the "soft lockups".
 
 config BOOTPARAM_SOFTLOCKUP_PANIC
         bool "Panic (Reboot) On Soft Lockups"
         depends on SOFTLOCKUP_DETECTOR
         help
           Say Y here to enable the kernel to panic on "soft lockups",
           which are bugs that cause the kernel to loop in kernel
           mode for more than 20 seconds (configurable using the watchdog_thresh
           sysctl), without giving other tasks a chance to run.
 
           The panic can be used in combination with panic_timeout,
           to cause the system to reboot automatically after a
           lockup has been detected. This feature is useful for
           high-availability systems that have uptime guarantees and
           where a lockup must be resolved ASAP.
 
           Say N if unsure.
 
 config HAVE_HARDLOCKUP_DETECTOR_BUDDY
         bool
         depends on SMP
         default y
 
 #
 # Global switch whether to build a hardlockup detector at all. It is available
 # only when the architecture supports at least one implementation. There are
 # two exceptions. The hardlockup detector is never enabled on:
 #
 #       s390: it reported many false positives there
 #
 #       sparc64: has a custom implementation which is not using the common
 #               hardlockup command line options and sysctl interface.
 #
 config HARDLOCKUP_DETECTOR
         bool "Detect Hard Lockups"
         depends on DEBUG_KERNEL && !S390 && !HARDLOCKUP_DETECTOR_SPARC64
         depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_BUDDY || HAVE_HARDLOCKUP_DETECTOR_ARCH
         imply HARDLOCKUP_DETECTOR_PERF
         imply HARDLOCKUP_DETECTOR_BUDDY
         imply HARDLOCKUP_DETECTOR_ARCH
         select LOCKUP_DETECTOR
 
         help
           Say Y here to enable the kernel to act as a watchdog to detect
           hard lockups.
 
           Hardlockups are bugs that cause the CPU to loop in kernel mode
           for more than 10 seconds, without letting other interrupts have a
           chance to run.  The current stack trace is displayed upon detection
           and the system will stay locked up.
 
 #
 # Note that arch-specific variants are always preferred.
 #
 config HARDLOCKUP_DETECTOR_PREFER_BUDDY
         bool "Prefer the buddy CPU hardlockup detector"
         depends on HARDLOCKUP_DETECTOR
         depends on HAVE_HARDLOCKUP_DETECTOR_PERF && HAVE_HARDLOCKUP_DETECTOR_BUDDY
         depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
         help
           Say Y here to prefer the buddy hardlockup detector over the perf one.
 
           With the buddy detector, each CPU uses its softlockup hrtimer
           to check that the next CPU is processing hrtimer interrupts by
           verifying that a counter is increasing.
 
           This hardlockup detector is useful on systems that don't have
           an arch-specific hardlockup detector or if resources needed
           for the hardlockup detector are better used for other things.
 
 config HARDLOCKUP_DETECTOR_PERF
         bool
         depends on HARDLOCKUP_DETECTOR
         depends on HAVE_HARDLOCKUP_DETECTOR_PERF && !HARDLOCKUP_DETECTOR_PREFER_BUDDY
         depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
         select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
 
 config HARDLOCKUP_DETECTOR_BUDDY
         bool
         depends on HARDLOCKUP_DETECTOR
         depends on HAVE_HARDLOCKUP_DETECTOR_BUDDY
         depends on !HAVE_HARDLOCKUP_DETECTOR_PERF || HARDLOCKUP_DETECTOR_PREFER_BUDDY
         depends on !HAVE_HARDLOCKUP_DETECTOR_ARCH
         select HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
 
 config HARDLOCKUP_DETECTOR_ARCH
         bool
         depends on HARDLOCKUP_DETECTOR
         depends on HAVE_HARDLOCKUP_DETECTOR_ARCH
         help
           The arch-specific implementation of the hardlockup detector will
           be used.
 
 #
 # Both the "perf" and "buddy" hardlockup detectors count hrtimer
 # interrupts. This config enables functions managing this common code.
 #
 config HARDLOCKUP_DETECTOR_COUNTS_HRTIMER
         bool
         select SOFTLOCKUP_DETECTOR
 
 #
 # Enables a timestamp based low pass filter to compensate for perf based
 # hard lockup detection which runs too fast due to turbo modes.
 #
 config HARDLOCKUP_CHECK_TIMESTAMP
         bool
 
 config BOOTPARAM_HARDLOCKUP_PANIC
         bool "Panic (Reboot) On Hard Lockups"
         depends on HARDLOCKUP_DETECTOR
         help
           Say Y here to enable the kernel to panic on "hard lockups",
           which are bugs that cause the kernel to loop in kernel
           mode with interrupts disabled for more than 10 seconds (configurable
           using the watchdog_thresh sysctl).
 
           Say N if unsure.
 
 config DETECT_HUNG_TASK
         bool "Detect Hung Tasks"
         depends on DEBUG_KERNEL
         default SOFTLOCKUP_DETECTOR
         help
           Say Y here to enable the kernel to detect "hung tasks",
           which are bugs that cause the task to be stuck in
           uninterruptible "D" state indefinitely.
 
           When a hung task is detected, the kernel will print the
           current stack trace (which you should report), but the
           task will stay in uninterruptible state. If lockdep is
           enabled then all held locks will also be reported. This
           feature has negligible overhead.
 
 config DEFAULT_HUNG_TASK_TIMEOUT
         int "Default timeout for hung task detection (in seconds)"
         depends on DETECT_HUNG_TASK
         default 120
         help
           This option controls the default timeout (in seconds) used
           to determine when a task has become non-responsive and should
           be considered hung.
 
           It can be adjusted at runtime via the kernel.hung_task_timeout_secs
           sysctl or by writing a value to
           /proc/sys/kernel/hung_task_timeout_secs.
 
           A timeout of 0 disables the check.  The default is two minutes.
           Keeping the default should be fine in most cases.
 
 config BOOTPARAM_HUNG_TASK_PANIC
         bool "Panic (Reboot) On Hung Tasks"
         depends on DETECT_HUNG_TASK
         help
           Say Y here to enable the kernel to panic on "hung tasks",
           which are bugs that cause the kernel to leave a task stuck
           in uninterruptible "D" state.
 
           The panic can be used in combination with panic_timeout,
           to cause the system to reboot automatically after a
           hung task has been detected. This feature is useful for
           high-availability systems that have uptime guarantees and
           where a hung tasks must be resolved ASAP.
 
           Say N if unsure.
 
 config WQ_WATCHDOG
         bool "Detect Workqueue Stalls"
         depends on DEBUG_KERNEL
         help
           Say Y here to enable stall detection on workqueues.  If a
           worker pool doesn't make forward progress on a pending work
           item for over a given amount of time, 30s by default, a
           warning message is printed along with dump of workqueue
           state.  This can be configured through kernel parameter
           "workqueue.watchdog_thresh" and its sysfs counterpart.
 
 config WQ_CPU_INTENSIVE_REPORT
         bool "Report per-cpu work items which hog CPU for too long"
         depends on DEBUG_KERNEL
         help
           Say Y here to enable reporting of concurrency-managed per-cpu work
           items that hog CPUs for longer than
           workqueue.cpu_intensive_thresh_us. Workqueue automatically
           detects and excludes them from concurrency management to prevent
           them from stalling other per-cpu work items. Occassional
           triggering may not necessarily indicate a problem. Repeated
           triggering likely indicates that the work item should be switched
           to use an unbound workqueue.
 
 config TEST_LOCKUP
         tristate "Test module to generate lockups"
         depends on m
         help
           This builds the "test_lockup" module that helps to make sure
           that watchdogs and lockup detectors are working properly.
 
           Depending on module parameters it could emulate soft or hard
           lockup, "hung task", or locking arbitrary lock for a long time.
           Also it could generate series of lockups with cooling-down periods.
 
           If unsure, say N.
 
 endmenu # "Debug lockups and hangs"
 
 menu "Scheduler Debugging"
 
 config SCHED_DEBUG
         bool "Collect scheduler debugging info"
         depends on DEBUG_KERNEL && DEBUG_FS
         default y
         help
           If you say Y here, the /sys/kernel/debug/sched file will be provided
           that can help debug the scheduler. The runtime overhead of this
           option is minimal.
 
 config SCHED_INFO
         bool
         default n
 
 config SCHEDSTATS
         bool "Collect scheduler statistics"
         depends on PROC_FS
         select SCHED_INFO
         help
           If you say Y here, additional code will be inserted into the
           scheduler and related routines to collect statistics about
           scheduler behavior and provide them in /proc/schedstat.  These
           stats may be useful for both tuning and debugging the scheduler
           If you aren't debugging the scheduler or trying to tune a specific
           application, you can say N to avoid the very slight overhead
           this adds.
 
 endmenu
 
 config DEBUG_TIMEKEEPING
         bool "Enable extra timekeeping sanity checking"
         help
           This option will enable additional timekeeping sanity checks
           which may be helpful when diagnosing issues where timekeeping
           problems are suspected.
 
           This may include checks in the timekeeping hotpaths, so this
           option may have a (very small) performance impact to some
           workloads.
 
           If unsure, say N.
 
 config DEBUG_PREEMPT
         bool "Debug preemptible kernel"
         depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
         help
           If you say Y here then the kernel will use a debug variant of the
           commonly used smp_processor_id() function and will print warnings
           if kernel code uses it in a preemption-unsafe way. Also, the kernel
           will detect preemption count underflows.
 
           This option has potential to introduce high runtime overhead,
           depending on workload as it triggers debugging routines for each
           this_cpu operation. It should only be used for debugging purposes.
 
 menu "Lock Debugging (spinlocks, mutexes, etc...)"
 
 config LOCK_DEBUGGING_SUPPORT
         bool
         depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
         default y
 
 config PROVE_LOCKING
         bool "Lock debugging: prove locking correctness"
         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
         select LOCKDEP
         select DEBUG_SPINLOCK
         select DEBUG_MUTEXES if !PREEMPT_RT
         select DEBUG_RT_MUTEXES if RT_MUTEXES
         select DEBUG_RWSEMS if !PREEMPT_RT
         select DEBUG_WW_MUTEX_SLOWPATH
         select DEBUG_LOCK_ALLOC
         select PREEMPT_COUNT if !ARCH_NO_PREEMPT
         select TRACE_IRQFLAGS
         default n
         help
          This feature enables the kernel to prove that all locking
          that occurs in the kernel runtime is mathematically
          correct: that under no circumstance could an arbitrary (and
          not yet triggered) combination of observed locking
          sequences (on an arbitrary number of CPUs, running an
          arbitrary number of tasks and interrupt contexts) cause a
          deadlock.
 
          In short, this feature enables the kernel to report locking
          related deadlocks before they actually occur.
 
          The proof does not depend on how hard and complex a
          deadlock scenario would be to trigger: how many
          participant CPUs, tasks and irq-contexts would be needed
          for it to trigger. The proof also does not depend on
          timing: if a race and a resulting deadlock is possible
          theoretically (no matter how unlikely the race scenario
          is), it will be proven so and will immediately be
          reported by the kernel (once the event is observed that
          makes the deadlock theoretically possible).
 
          If a deadlock is impossible (i.e. the locking rules, as
          observed by the kernel, are mathematically correct), the
          kernel reports nothing.
 
          NOTE: this feature can also be enabled for rwlocks, mutexes
          and rwsems - in which case all dependencies between these
          different locking variants are observed and mapped too, and
          the proof of observed correctness is also maintained for an
          arbitrary combination of these separate locking variants.
 
          For more details, see Documentation/locking/lockdep-design.rst.
 
 config PROVE_RAW_LOCK_NESTING
         bool "Enable raw_spinlock - spinlock nesting checks"
         depends on PROVE_LOCKING
         default n
         help
          Enable the raw_spinlock vs. spinlock nesting checks which ensure
          that the lock nesting rules for PREEMPT_RT enabled kernels are
          not violated.
 
          NOTE: There are known nesting problems. So if you enable this
          option expect lockdep splats until these problems have been fully
          addressed which is work in progress. This config switch allows to
          identify and analyze these problems. It will be removed and the
          check permanently enabled once the main issues have been fixed.
 
          If unsure, select N.
 
 config LOCK_STAT
         bool "Lock usage statistics"
         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
         select LOCKDEP
         select DEBUG_SPINLOCK
         select DEBUG_MUTEXES if !PREEMPT_RT
         select DEBUG_RT_MUTEXES if RT_MUTEXES
         select DEBUG_LOCK_ALLOC
         default n
         help
          This feature enables tracking lock contention points
 
          For more details, see Documentation/locking/lockstat.rst
 
          This also enables lock events required by "perf lock",
          subcommand of perf.
          If you want to use "perf lock", you also need to turn on
          CONFIG_EVENT_TRACING.
 
          CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
          (CONFIG_LOCKDEP defines "acquire" and "release" events.)
 
 config DEBUG_RT_MUTEXES
         bool "RT Mutex debugging, deadlock detection"
         depends on DEBUG_KERNEL && RT_MUTEXES
         help
          This allows rt mutex semantics violations and rt mutex related
          deadlocks (lockups) to be detected and reported automatically.
 
 config DEBUG_SPINLOCK
         bool "Spinlock and rw-lock debugging: basic checks"
         depends on DEBUG_KERNEL
         select UNINLINE_SPIN_UNLOCK
         help
           Say Y here and build SMP to catch missing spinlock initialization
           and certain other kinds of spinlock errors commonly made.  This is
           best used in conjunction with the NMI watchdog so that spinlock
           deadlocks are also debuggable.
 
 config DEBUG_MUTEXES
         bool "Mutex debugging: basic checks"
         depends on DEBUG_KERNEL && !PREEMPT_RT
         help
          This feature allows mutex semantics violations to be detected and
          reported.
 
 config DEBUG_WW_MUTEX_SLOWPATH
         bool "Wait/wound mutex debugging: Slowpath testing"
         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
         select DEBUG_LOCK_ALLOC
         select DEBUG_SPINLOCK
         select DEBUG_MUTEXES if !PREEMPT_RT
         select DEBUG_RT_MUTEXES if PREEMPT_RT
         help
          This feature enables slowpath testing for w/w mutex users by
          injecting additional -EDEADLK wound/backoff cases. Together with
          the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
          will test all possible w/w mutex interface abuse with the
          exception of simply not acquiring all the required locks.
          Note that this feature can introduce significant overhead, so
          it really should not be enabled in a production or distro kernel,
          even a debug kernel.  If you are a driver writer, enable it.  If
          you are a distro, do not.
 
 config DEBUG_RWSEMS
         bool "RW Semaphore debugging: basic checks"
         depends on DEBUG_KERNEL && !PREEMPT_RT
         help
           This debugging feature allows mismatched rw semaphore locks
           and unlocks to be detected and reported.
 
 config DEBUG_LOCK_ALLOC
         bool "Lock debugging: detect incorrect freeing of live locks"
         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
         select DEBUG_SPINLOCK
         select DEBUG_MUTEXES if !PREEMPT_RT
         select DEBUG_RT_MUTEXES if RT_MUTEXES
         select LOCKDEP
         help
          This feature will check whether any held lock (spinlock, rwlock,
          mutex or rwsem) is incorrectly freed by the kernel, via any of the
          memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
          vfree(), etc.), whether a live lock is incorrectly reinitialized via
          spin_lock_init()/mutex_init()/etc., or whether there is any lock
          held during task exit.
 
 config LOCKDEP
         bool
         depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
         select STACKTRACE
         select KALLSYMS
         select KALLSYMS_ALL
 
 config LOCKDEP_SMALL
         bool
 
 config LOCKDEP_BITS
         int "Bitsize for MAX_LOCKDEP_ENTRIES"
         depends on LOCKDEP && !LOCKDEP_SMALL
         range 10 30
         default 15
         help
           Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message.
 
 config LOCKDEP_CHAINS_BITS
         int "Bitsize for MAX_LOCKDEP_CHAINS"
         depends on LOCKDEP && !LOCKDEP_SMALL
         range 10 30
         default 16
         help
           Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message.
 
 config LOCKDEP_STACK_TRACE_BITS
         int "Bitsize for MAX_STACK_TRACE_ENTRIES"
         depends on LOCKDEP && !LOCKDEP_SMALL
         range 10 30
         default 19
         help
           Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message.
 
 config LOCKDEP_STACK_TRACE_HASH_BITS
         int "Bitsize for STACK_TRACE_HASH_SIZE"
         depends on LOCKDEP && !LOCKDEP_SMALL
         range 10 30
         default 14
         help
           Try increasing this value if you need large STACK_TRACE_HASH_SIZE.
 
 config LOCKDEP_CIRCULAR_QUEUE_BITS
         int "Bitsize for elements in circular_queue struct"
         depends on LOCKDEP
         range 10 30
         default 12
         help
           Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
 
 config DEBUG_LOCKDEP
         bool "Lock dependency engine debugging"
         depends on DEBUG_KERNEL && LOCKDEP
         select DEBUG_IRQFLAGS
         help
           If you say Y here, the lock dependency engine will do
           additional runtime checks to debug itself, at the price
           of more runtime overhead.
 
 config DEBUG_ATOMIC_SLEEP
         bool "Sleep inside atomic section checking"
         select PREEMPT_COUNT
         depends on DEBUG_KERNEL
         depends on !ARCH_NO_PREEMPT
         help
           If you say Y here, various routines which may sleep will become very
           noisy if they are called inside atomic sections: when a spinlock is
           held, inside an rcu read side critical section, inside preempt disabled
           sections, inside an interrupt, etc...
 
 config DEBUG_LOCKING_API_SELFTESTS
         bool "Locking API boot-time self-tests"
         depends on DEBUG_KERNEL
         help
           Say Y here if you want the kernel to run a short self-test during
           bootup. The self-test checks whether common types of locking bugs
           are detected by debugging mechanisms or not. (if you disable
           lock debugging then those bugs won't be detected of course.)
           The following locking APIs are covered: spinlocks, rwlocks,
           mutexes and rwsems.
 
 config LOCK_TORTURE_TEST
         tristate "torture tests for locking"
         depends on DEBUG_KERNEL
         select TORTURE_TEST
         help
           This option provides a kernel module that runs torture tests
           on kernel locking primitives.  The kernel module may be built
           after the fact on the running kernel to be tested, if desired.
 
           Say Y here if you want kernel locking-primitive torture tests
           to be built into the kernel.
           Say M if you want these torture tests to build as a module.
           Say N if you are unsure.
 
 config WW_MUTEX_SELFTEST
         tristate "Wait/wound mutex selftests"
         help
           This option provides a kernel module that runs tests on the
           on the struct ww_mutex locking API.
 
           It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
           with this test harness.
 
           Say M if you want these self tests to build as a module.
           Say N if you are unsure.
 
 config SCF_TORTURE_TEST
         tristate "torture tests for smp_call_function*()"
         depends on DEBUG_KERNEL
         select TORTURE_TEST
         help
           This option provides a kernel module that runs torture tests
           on the smp_call_function() family of primitives.  The kernel
           module may be built after the fact on the running kernel to
           be tested, if desired.
 
 config CSD_LOCK_WAIT_DEBUG
         bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
         depends on DEBUG_KERNEL
         depends on 64BIT
         default n
         help
           This option enables debug prints when CPUs are slow to respond
           to the smp_call_function*() IPI wrappers.  These debug prints
           include the IPI handler function currently executing (if any)
           and relevant stack traces.
 
 config CSD_LOCK_WAIT_DEBUG_DEFAULT
         bool "Default csd_lock_wait() debugging on at boot time"
         depends on CSD_LOCK_WAIT_DEBUG
         depends on 64BIT
         default n
         help
           This option causes the csdlock_debug= kernel boot parameter to
           default to 1 (basic debugging) instead of 0 (no debugging).
 
 endmenu # lock debugging
 
 config TRACE_IRQFLAGS
         depends on TRACE_IRQFLAGS_SUPPORT
         bool
         help
           Enables hooks to interrupt enabling and disabling for
           either tracing or lock debugging.
 
 config TRACE_IRQFLAGS_NMI
         def_bool y
         depends on TRACE_IRQFLAGS
         depends on TRACE_IRQFLAGS_NMI_SUPPORT
 
 config NMI_CHECK_CPU
         bool "Debugging for CPUs failing to respond to backtrace requests"
         depends on DEBUG_KERNEL
         depends on X86
         default n
         help
           Enables debug prints when a CPU fails to respond to a given
           backtrace NMI.  These prints provide some reasons why a CPU
           might legitimately be failing to respond, for example, if it
           is offline of if ignore_nmis is set.
 
 config DEBUG_IRQFLAGS
         bool "Debug IRQ flag manipulation"
         help
           Enables checks for potentially unsafe enabling or disabling of
           interrupts, such as calling raw_local_irq_restore() when interrupts
           are enabled.
 
 config STACKTRACE
         bool "Stack backtrace support"
         depends on STACKTRACE_SUPPORT
         help
           This option causes the kernel to create a /proc/pid/stack for
           every process, showing its current stack trace.
           It is also used by various kernel debugging features that require
           stack trace generation.
 
 config WARN_ALL_UNSEEDED_RANDOM
         bool "Warn for all uses of unseeded randomness"
         default n
         help
           Some parts of the kernel contain bugs relating to their use of
           cryptographically secure random numbers before it's actually possible
           to generate those numbers securely. This setting ensures that these
           flaws don't go unnoticed, by enabling a message, should this ever
           occur. This will allow people with obscure setups to know when things
           are going wrong, so that they might contact developers about fixing
           it.
 
           Unfortunately, on some models of some architectures getting
           a fully seeded CRNG is extremely difficult, and so this can
           result in dmesg getting spammed for a surprisingly long
           time.  This is really bad from a security perspective, and
           so architecture maintainers really need to do what they can
           to get the CRNG seeded sooner after the system is booted.
           However, since users cannot do anything actionable to
           address this, by default this option is disabled.
 
           Say Y here if you want to receive warnings for all uses of
           unseeded randomness.  This will be of use primarily for
           those developers interested in improving the security of
           Linux kernels running on their architecture (or
           subarchitecture).
 
 config DEBUG_KOBJECT
         bool "kobject debugging"
         depends on DEBUG_KERNEL
         help
           If you say Y here, some extra kobject debugging messages will be sent
           to the syslog.
 
 config DEBUG_KOBJECT_RELEASE
         bool "kobject release debugging"
         depends on DEBUG_OBJECTS_TIMERS
         help
           kobjects are reference counted objects.  This means that their
           last reference count put is not predictable, and the kobject can
           live on past the point at which a driver decides to drop its
           initial reference to the kobject gained on allocation.  An
           example of this would be a struct device which has just been
           unregistered.
 
           However, some buggy drivers assume that after such an operation,
           the memory backing the kobject can be immediately freed.  This
           goes completely against the principles of a refcounted object.
 
           If you say Y here, the kernel will delay the release of kobjects
           on the last reference count to improve the visibility of this
           kind of kobject release bug.
 
 config HAVE_DEBUG_BUGVERBOSE
         bool
 
 menu "Debug kernel data structures"
 
 config DEBUG_LIST
         bool "Debug linked list manipulation"
         depends on DEBUG_KERNEL
         select LIST_HARDENED
         help
           Enable this to turn on extended checks in the linked-list walking
           routines.
 
           This option trades better quality error reports for performance, and
           is more suitable for kernel debugging. If you care about performance,
           you should only enable CONFIG_LIST_HARDENED instead.
 
           If unsure, say N.
 
 config DEBUG_PLIST
         bool "Debug priority linked list manipulation"
         depends on DEBUG_KERNEL
         help
           Enable this to turn on extended checks in the priority-ordered
           linked-list (plist) walking routines.  This checks the entire
           list multiple times during each manipulation.
 
           If unsure, say N.
 
 config DEBUG_SG
         bool "Debug SG table operations"
         depends on DEBUG_KERNEL
         help
           Enable this to turn on checks on scatter-gather tables. This can
           help find problems with drivers that do not properly initialize
           their sg tables.
 
           If unsure, say N.
 
 config DEBUG_NOTIFIERS
         bool "Debug notifier call chains"
         depends on DEBUG_KERNEL
         help
           Enable this to turn on sanity checking for notifier call chains.
           This is most useful for kernel developers to make sure that
           modules properly unregister themselves from notifier chains.
           This is a relatively cheap check but if you care about maximum
           performance, say N.
 
 config DEBUG_CLOSURES
         bool "Debug closures (bcache async widgits)"
         depends on CLOSURES
         select DEBUG_FS
         help
           Keeps all active closures in a linked list and provides a debugfs
           interface to list them, which makes it possible to see asynchronous
           operations that get stuck.
 
 config DEBUG_MAPLE_TREE
         bool "Debug maple trees"
         depends on DEBUG_KERNEL
         help
           Enable maple tree debugging information and extra validations.
 
           If unsure, say N.
 
 endmenu
 
 source "kernel/rcu/Kconfig.debug"
 
 config DEBUG_WQ_FORCE_RR_CPU
         bool "Force round-robin CPU selection for unbound work items"
         depends on DEBUG_KERNEL
         default n
         help
           Workqueue used to implicitly guarantee that work items queued
           without explicit CPU specified are put on the local CPU.  This
           guarantee is no longer true and while local CPU is still
           preferred work items may be put on foreign CPUs.  Kernel
           parameter "workqueue.debug_force_rr_cpu" is added to force
           round-robin CPU selection to flush out usages which depend on the
           now broken guarantee.  This config option enables the debug
           feature by default.  When enabled, memory and cache locality will
           be impacted.
 
 config CPU_HOTPLUG_STATE_CONTROL
         bool "Enable CPU hotplug state control"
         depends on DEBUG_KERNEL
         depends on HOTPLUG_CPU
         default n
         help
           Allows to write steps between "offline" and "online" to the CPUs
           sysfs target file so states can be stepped granular. This is a debug
           option for now as the hotplug machinery cannot be stopped and
           restarted at arbitrary points yet.
 
           Say N if your are unsure.
 
 config LATENCYTOP
         bool "Latency measuring infrastructure"
         depends on DEBUG_KERNEL
         depends on STACKTRACE_SUPPORT
         depends on PROC_FS
         depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
         select KALLSYMS
         select KALLSYMS_ALL
         select STACKTRACE
         select SCHEDSTATS
         help
           Enable this option if you want to use the LatencyTOP tool
           to find out which userspace is blocking on what kernel operations.
 
 config DEBUG_CGROUP_REF
         bool "Disable inlining of cgroup css reference count functions"
         depends on DEBUG_KERNEL
         depends on CGROUPS
         depends on KPROBES
         default n
         help
           Force cgroup css reference count functions to not be inlined so
           that they can be kprobed for debugging.
 
 source "kernel/trace/Kconfig"
 
 config PROVIDE_OHCI1394_DMA_INIT
         bool "Remote debugging over FireWire early on boot"
         depends on PCI && X86
         help
           If you want to debug problems which hang or crash the kernel early
           on boot and the crashing machine has a FireWire port, you can use
           this feature to remotely access the memory of the crashed machine
           over FireWire. This employs remote DMA as part of the OHCI1394
           specification which is now the standard for FireWire controllers.
 
           With remote DMA, you can monitor the printk buffer remotely using
           firescope and access all memory below 4GB using fireproxy from gdb.
           Even controlling a kernel debugger is possible using remote DMA.
 
           Usage:
 
           If ohci1394_dma=early is used as boot parameter, it will initialize
           all OHCI1394 controllers which are found in the PCI config space.
 
           As all changes to the FireWire bus such as enabling and disabling
           devices cause a bus reset and thereby disable remote DMA for all
           devices, be sure to have the cable plugged and FireWire enabled on
           the debugging host before booting the debug target for debugging.
 
           This code (~1k) is freed after boot. By then, the firewire stack
           in charge of the OHCI-1394 controllers should be used instead.
 
           See Documentation/core-api/debugging-via-ohci1394.rst for more information.
 
 source "samples/Kconfig"
 
 config ARCH_HAS_DEVMEM_IS_ALLOWED
         bool
 
 config STRICT_DEVMEM
         bool "Filter access to /dev/mem"
         depends on MMU && DEVMEM
         depends on ARCH_HAS_DEVMEM_IS_ALLOWED || GENERIC_LIB_DEVMEM_IS_ALLOWED
         default y if PPC || X86 || ARM64
         help
           If this option is disabled, you allow userspace (root) access to all
           of memory, including kernel and userspace memory. Accidental
           access to this is obviously disastrous, but specific access can
           be used by people debugging the kernel. Note that with PAT support
           enabled, even in this case there are restrictions on /dev/mem
           use due to the cache aliasing requirements.
 
           If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem
           file only allows userspace access to PCI space and the BIOS code and
           data regions.  This is sufficient for dosemu and X and all common
           users of /dev/mem.
 
           If in doubt, say Y.
 
 config IO_STRICT_DEVMEM
         bool "Filter I/O access to /dev/mem"
         depends on STRICT_DEVMEM
         help
           If this option is disabled, you allow userspace (root) access to all
           io-memory regardless of whether a driver is actively using that
           range.  Accidental access to this is obviously disastrous, but
           specific access can be used by people debugging kernel drivers.
 
           If this option is switched on, the /dev/mem file only allows
           userspace access to *idle* io-memory ranges (see /proc/iomem) This
           may break traditional users of /dev/mem (dosemu, legacy X, etc...)
           if the driver using a given range cannot be disabled.
 
           If in doubt, say Y.
 
 menu "$(SRCARCH) Debugging"
 
 source "arch/$(SRCARCH)/Kconfig.debug"
 
 endmenu
 
 menu "Kernel Testing and Coverage"
 
 source "lib/kunit/Kconfig"
 
 config NOTIFIER_ERROR_INJECTION
         tristate "Notifier error injection"
         depends on DEBUG_KERNEL
         select DEBUG_FS
         help
           This option provides the ability to inject artificial errors to
           specified notifier chain callbacks. It is useful to test the error
           handling of notifier call chain failures.
 
           Say N if unsure.
 
 config PM_NOTIFIER_ERROR_INJECT
         tristate "PM notifier error injection module"
         depends on PM && NOTIFIER_ERROR_INJECTION
         default m if PM_DEBUG
         help
           This option provides the ability to inject artificial errors to
           PM notifier chain callbacks.  It is controlled through debugfs
           interface /sys/kernel/debug/notifier-error-inject/pm
 
           If the notifier call chain should be failed with some events
           notified, write the error code to "actions/<notifier event>/error".
 
           Example: Inject PM suspend error (-12 = -ENOMEM)
 
           # cd /sys/kernel/debug/notifier-error-inject/pm/
           # echo -12 > actions/PM_SUSPEND_PREPARE/error
           # echo mem > /sys/power/state
           bash: echo: write error: Cannot allocate memory
 
           To compile this code as a module, choose M here: the module will
           be called pm-notifier-error-inject.
 
           If unsure, say N.
 
 config OF_RECONFIG_NOTIFIER_ERROR_INJECT
         tristate "OF reconfig notifier error injection module"
         depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
         help
           This option provides the ability to inject artificial errors to
           OF reconfig notifier chain callbacks.  It is controlled
           through debugfs interface under
           /sys/kernel/debug/notifier-error-inject/OF-reconfig/
 
           If the notifier call chain should be failed with some events
           notified, write the error code to "actions/<notifier event>/error".
 
           To compile this code as a module, choose M here: the module will
           be called of-reconfig-notifier-error-inject.
 
           If unsure, say N.
 
 config NETDEV_NOTIFIER_ERROR_INJECT
         tristate "Netdev notifier error injection module"
         depends on NET && NOTIFIER_ERROR_INJECTION
         help
           This option provides the ability to inject artificial errors to
           netdevice notifier chain callbacks.  It is controlled through debugfs
           interface /sys/kernel/debug/notifier-error-inject/netdev
 
           If the notifier call chain should be failed with some events
           notified, write the error code to "actions/<notifier event>/error".
 
           Example: Inject netdevice mtu change error (-22 = -EINVAL)
 
           # cd /sys/kernel/debug/notifier-error-inject/netdev
           # echo -22 > actions/NETDEV_CHANGEMTU/error
           # ip link set eth0 mtu 1024
           RTNETLINK answers: Invalid argument
 
           To compile this code as a module, choose M here: the module will
           be called netdev-notifier-error-inject.
 
           If unsure, say N.
 
 config FUNCTION_ERROR_INJECTION
         bool "Fault-injections of functions"
         depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
         help
           Add fault injections into various functions that are annotated with
           ALLOW_ERROR_INJECTION() in the kernel. BPF may also modify the return
           value of these functions. This is useful to test error paths of code.
 
           If unsure, say N
 
 config FAULT_INJECTION
         bool "Fault-injection framework"
         depends on DEBUG_KERNEL
         help
           Provide fault-injection framework.
           For more details, see Documentation/fault-injection/.
 
 config FAILSLAB
         bool "Fault-injection capability for kmalloc"
         depends on FAULT_INJECTION
         help
           Provide fault-injection capability for kmalloc.
 
 config FAIL_PAGE_ALLOC
         bool "Fault-injection capability for alloc_pages()"
         depends on FAULT_INJECTION
         help
           Provide fault-injection capability for alloc_pages().
 
 config FAULT_INJECTION_USERCOPY
         bool "Fault injection capability for usercopy functions"
         depends on FAULT_INJECTION
         help
           Provides fault-injection capability to inject failures
           in usercopy functions (copy_from_user(), get_user(), ...).
 
 config FAIL_MAKE_REQUEST
         bool "Fault-injection capability for disk IO"
         depends on FAULT_INJECTION && BLOCK
         help
           Provide fault-injection capability for disk IO.
 
 config FAIL_IO_TIMEOUT
         bool "Fault-injection capability for faking disk interrupts"
         depends on FAULT_INJECTION && BLOCK
         help
           Provide fault-injection capability on end IO handling. This
           will make the block layer "forget" an interrupt as configured,
           thus exercising the error handling.
 
           Only works with drivers that use the generic timeout handling,
           for others it won't do anything.
 
 config FAIL_FUTEX
         bool "Fault-injection capability for futexes"
         select DEBUG_FS
         depends on FAULT_INJECTION && FUTEX
         help
           Provide fault-injection capability for futexes.
 
 config FAULT_INJECTION_DEBUG_FS
         bool "Debugfs entries for fault-injection capabilities"
         depends on FAULT_INJECTION && SYSFS && DEBUG_FS
         help
           Enable configuration of fault-injection capabilities via debugfs.
 
 config FAIL_FUNCTION
         bool "Fault-injection capability for functions"
         depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
         help
           Provide function-based fault-injection capability.
           This will allow you to override a specific function with a return
           with given return value. As a result, function caller will see
           an error value and have to handle it. This is useful to test the
           error handling in various subsystems.
 
 config FAIL_MMC_REQUEST
         bool "Fault-injection capability for MMC IO"
         depends on FAULT_INJECTION_DEBUG_FS && MMC
         help
           Provide fault-injection capability for MMC IO.
           This will make the mmc core return data errors. This is
           useful to test the error handling in the mmc block device
           and to test how the mmc host driver handles retries from
           the block device.
 
 config FAIL_SUNRPC
         bool "Fault-injection capability for SunRPC"
         depends on FAULT_INJECTION_DEBUG_FS && SUNRPC_DEBUG
         help
           Provide fault-injection capability for SunRPC and
           its consumers.
 
 config FAULT_INJECTION_CONFIGFS
         bool "Configfs interface for fault-injection capabilities"
         depends on FAULT_INJECTION
         select CONFIGFS_FS
         help
           This option allows configfs-based drivers to dynamically configure
           fault-injection via configfs.  Each parameter for driver-specific
           fault-injection can be made visible as a configfs attribute in a
           configfs group.
 
 
 config FAULT_INJECTION_STACKTRACE_FILTER
         bool "stacktrace filter for fault-injection capabilities"
         depends on FAULT_INJECTION
         depends on (FAULT_INJECTION_DEBUG_FS || FAULT_INJECTION_CONFIGFS) && STACKTRACE_SUPPORT
         select STACKTRACE
         depends on FRAME_POINTER || MIPS || PPC || S390 || MICROBLAZE || ARM || ARC || X86
         help
           Provide stacktrace filter for fault-injection capabilities
 
 config ARCH_HAS_KCOV
         bool
         help
           An architecture should select this when it can successfully
           build and run with CONFIG_KCOV. This typically requires
           disabling instrumentation for some early boot code.
 
 config CC_HAS_SANCOV_TRACE_PC
         def_bool $(cc-option,-fsanitize-coverage=trace-pc)
 
 
 config KCOV
         bool "Code coverage for fuzzing"
         depends on ARCH_HAS_KCOV
         depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS
         depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \
                    GCC_VERSION >= 120000 || CC_IS_CLANG
         select DEBUG_FS
         select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC
         select OBJTOOL if HAVE_NOINSTR_HACK
         help
           KCOV exposes kernel code coverage information in a form suitable
           for coverage-guided fuzzing (randomized testing).
 
           For more details, see Documentation/dev-tools/kcov.rst.
 
 config KCOV_ENABLE_COMPARISONS
         bool "Enable comparison operands collection by KCOV"
         depends on KCOV
         depends on $(cc-option,-fsanitize-coverage=trace-cmp)
         help
           KCOV also exposes operands of every comparison in the instrumented
           code along with operand sizes and PCs of the comparison instructions.
           These operands can be used by fuzzing engines to improve the quality
           of fuzzing coverage.
 
 config KCOV_INSTRUMENT_ALL
         bool "Instrument all code by default"
         depends on KCOV
         default y
         help
           If you are doing generic system call fuzzing (like e.g. syzkaller),
           then you will want to instrument the whole kernel and you should
           say y here. If you are doing more targeted fuzzing (like e.g.
           filesystem fuzzing with AFL) then you will want to enable coverage
           for more specific subsets of files, and should say n here.
 
 config KCOV_IRQ_AREA_SIZE
         hex "Size of interrupt coverage collection area in words"
         depends on KCOV
         default 0x40000
         help
           KCOV uses preallocated per-cpu areas to collect coverage from
           soft interrupts. This specifies the size of those areas in the
           number of unsigned long words.
 
 menuconfig RUNTIME_TESTING_MENU
         bool "Runtime Testing"
         default y
 
 if RUNTIME_TESTING_MENU
 
 config TEST_DHRY
         tristate "Dhrystone benchmark test"
         help
           Enable this to include the Dhrystone 2.1 benchmark.  This test
           calculates the number of Dhrystones per second, and the number of
           DMIPS (Dhrystone MIPS) obtained when the Dhrystone score is divided
           by 1757 (the number of Dhrystones per second obtained on the VAX
           11/780, nominally a 1 MIPS machine).
 
           To run the benchmark, it needs to be enabled explicitly, either from
           the kernel command line (when built-in), or from userspace (when
           built-in or modular).
 
           Run once during kernel boot:
 
               test_dhry.run
 
           Set number of iterations from kernel command line:
 
               test_dhry.iterations=<n>
 
           Set number of iterations from userspace:
 
               echo <n> > /sys/module/test_dhry/parameters/iterations
 
           Trigger manual run from userspace:
 
               echo y > /sys/module/test_dhry/parameters/run
 
           If the number of iterations is <= 0, the test will devise a suitable
           number of iterations (test runs for at least 2s) automatically.
           This process takes ca. 4s.
 
           If unsure, say N.
 
 config LKDTM
         tristate "Linux Kernel Dump Test Tool Module"
         depends on DEBUG_FS
         help
         This module enables testing of the different dumping mechanisms by
         inducing system failures at predefined crash points.
         If you don't need it: say N
         Choose M here to compile this code as a module. The module will be
         called lkdtm.
 
         Documentation on how to use the module can be found in
         Documentation/fault-injection/provoke-crashes.rst
 
 config CPUMASK_KUNIT_TEST
         tristate "KUnit test for cpumask" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Enable to turn on cpumask tests, running at boot or module load time.
 
           For more information on KUnit and unit tests in general, please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config TEST_LIST_SORT
         tristate "Linked list sorting test" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Enable this to turn on 'list_sort()' function test. This test is
           executed only once during system boot (so affects only boot time),
           or at module load time.
 
           If unsure, say N.
 
 config TEST_MIN_HEAP
         tristate "Min heap test"
         depends on DEBUG_KERNEL || m
         help
           Enable this to turn on min heap function tests. This test is
           executed only once during system boot (so affects only boot time),
           or at module load time.
 
           If unsure, say N.
 
 config TEST_SORT
         tristate "Array-based sort test" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This option enables the self-test function of 'sort()' at boot,
           or at module load time.
 
           If unsure, say N.
 
 config TEST_DIV64
         tristate "64bit/32bit division and modulo test"
         depends on DEBUG_KERNEL || m
         help
           Enable this to turn on 'do_div()' function test. This test is
           executed only once during system boot (so affects only boot time),
           or at module load time.
 
           If unsure, say N.
 
 config TEST_IOV_ITER
         tristate "Test iov_iter operation" if !KUNIT_ALL_TESTS
         depends on KUNIT
         depends on MMU
         default KUNIT_ALL_TESTS
         help
           Enable this to turn on testing of the operation of the I/O iterator
           (iov_iter). This test is executed only once during system boot (so
           affects only boot time), or at module load time.
 
           If unsure, say N.
 
 config KPROBES_SANITY_TEST
         tristate "Kprobes sanity tests" if !KUNIT_ALL_TESTS
         depends on DEBUG_KERNEL
         depends on KPROBES
         depends on KUNIT
         select STACKTRACE if ARCH_CORRECT_STACKTRACE_ON_KRETPROBE
         default KUNIT_ALL_TESTS
         help
           This option provides for testing basic kprobes functionality on
           boot. Samples of kprobe and kretprobe are inserted and
           verified for functionality.
 
           Say N if you are unsure.
 
 config FPROBE_SANITY_TEST
         bool "Self test for fprobe"
         depends on DEBUG_KERNEL
         depends on FPROBE
         depends on KUNIT=y
         help
           This option will enable testing the fprobe when the system boot.
           A series of tests are made to verify that the fprobe is functioning
           properly.
 
           Say N if you are unsure.
 
 config BACKTRACE_SELF_TEST
         tristate "Self test for the backtrace code"
         depends on DEBUG_KERNEL
         help
           This option provides a kernel module that can be used to test
           the kernel stack backtrace code. This option is not useful
           for distributions or general kernels, but only for kernel
           developers working on architecture code.
 
           Note that if you want to also test saved backtraces, you will
           have to enable STACKTRACE as well.
 
           Say N if you are unsure.
 
 config TEST_REF_TRACKER
         tristate "Self test for reference tracker"
         depends on DEBUG_KERNEL && STACKTRACE_SUPPORT
         select REF_TRACKER
         help
           This option provides a kernel module performing tests
           using reference tracker infrastructure.
 
           Say N if you are unsure.
 
 config RBTREE_TEST
         tristate "Red-Black tree test"
         depends on DEBUG_KERNEL
         help
           A benchmark measuring the performance of the rbtree library.
           Also includes rbtree invariant checks.
 
 config REED_SOLOMON_TEST
         tristate "Reed-Solomon library test"
         depends on DEBUG_KERNEL || m
         select REED_SOLOMON
         select REED_SOLOMON_ENC16
         select REED_SOLOMON_DEC16
         help
           This option enables the self-test function of rslib at boot,
           or at module load time.
 
           If unsure, say N.
 
 config INTERVAL_TREE_TEST
         tristate "Interval tree test"
         depends on DEBUG_KERNEL
         select INTERVAL_TREE
         help
           A benchmark measuring the performance of the interval tree library
 
 config PERCPU_TEST
         tristate "Per cpu operations test"
         depends on m && DEBUG_KERNEL
         help
           Enable this option to build test module which validates per-cpu
           operations.
 
           If unsure, say N.
 
 config ATOMIC64_SELFTEST
         tristate "Perform an atomic64_t self-test"
         help
           Enable this option to test the atomic64_t functions at boot or
           at module load time.
 
           If unsure, say N.
 
 config ASYNC_RAID6_TEST
         tristate "Self test for hardware accelerated raid6 recovery"
         depends on ASYNC_RAID6_RECOV
         select ASYNC_MEMCPY
         help
           This is a one-shot self test that permutes through the
           recovery of all the possible two disk failure scenarios for a
           N-disk array.  Recovery is performed with the asynchronous
           raid6 recovery routines, and will optionally use an offload
           engine if one is available.
 
           If unsure, say N.
 
 config TEST_HEXDUMP
         tristate "Test functions located in the hexdump module at runtime"
 
 config STRING_KUNIT_TEST
         tristate "KUnit test string functions at runtime" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
 
 config STRING_HELPERS_KUNIT_TEST
         tristate "KUnit test string helpers at runtime" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
 
 config TEST_KSTRTOX
         tristate "Test kstrto*() family of functions at runtime"
 
 config TEST_PRINTF
         tristate "Test printf() family of functions at runtime"
 
 config TEST_SCANF
         tristate "Test scanf() family of functions at runtime"
 
 config TEST_BITMAP
         tristate "Test bitmap_*() family of functions at runtime"
         help
           Enable this option to test the bitmap functions at boot.
 
           If unsure, say N.
 
 config TEST_UUID
         tristate "Test functions located in the uuid module at runtime"
 
 config TEST_XARRAY
         tristate "Test the XArray code at runtime"
 
 config TEST_MAPLE_TREE
         tristate "Test the Maple Tree code at runtime or module load"
         help
           Enable this option to test the maple tree code functions at boot, or
           when the module is loaded. Enable "Debug Maple Trees" will enable
           more verbose output on failures.
 
           If unsure, say N.
 
 config TEST_RHASHTABLE
         tristate "Perform selftest on resizable hash table"
         help
           Enable this option to test the rhashtable functions at boot.
 
           If unsure, say N.
 
 config TEST_IDA
         tristate "Perform selftest on IDA functions"
 
 config TEST_PARMAN
         tristate "Perform selftest on priority array manager"
         depends on PARMAN
         help
           Enable this option to test priority array manager on boot
           (or module load).
 
           If unsure, say N.
 
 config TEST_IRQ_TIMINGS
         bool "IRQ timings selftest"
         depends on IRQ_TIMINGS
         help
           Enable this option to test the irq timings code on boot.
 
           If unsure, say N.
 
 config TEST_LKM
         tristate "Test module loading with 'hello world' module"
         depends on m
         help
           This builds the "test_module" module that emits "Hello, world"
           on printk when loaded. It is designed to be used for basic
           evaluation of the module loading subsystem (for example when
           validating module verification). It lacks any extra dependencies,
           and will not normally be loaded by the system unless explicitly
           requested by name.
 
           If unsure, say N.
 
 config TEST_BITOPS
         tristate "Test module for compilation of bitops operations"
         help
           This builds the "test_bitops" module that is much like the
           TEST_LKM module except that it does a basic exercise of the
           set/clear_bit macros and get_count_order/long to make sure there are
           no compiler warnings from C=1 sparse checker or -Wextra
           compilations. It has no dependencies and doesn't run or load unless
           explicitly requested by name.  for example: modprobe test_bitops.
 
           If unsure, say N.
 
 config TEST_VMALLOC
         tristate "Test module for stress/performance analysis of vmalloc allocator"
         default n
        depends on MMU
         depends on m
         help
           This builds the "test_vmalloc" module that should be used for
           stress and performance analysis. So, any new change for vmalloc
           subsystem can be evaluated from performance and stability point
           of view.
 
           If unsure, say N.
 
 config TEST_BPF
         tristate "Test BPF filter functionality"
         depends on m && NET
         help
           This builds the "test_bpf" module that runs various test vectors
           against the BPF interpreter or BPF JIT compiler depending on the
           current setting. This is in particular useful for BPF JIT compiler
           development, but also to run regression tests against changes in
           the interpreter code. It also enables test stubs for eBPF maps and
           verifier used by user space verifier testsuite.
 
           If unsure, say N.
 
 config TEST_BLACKHOLE_DEV
         tristate "Test blackhole netdev functionality"
         depends on m && NET
         help
           This builds the "test_blackhole_dev" module that validates the
           data path through this blackhole netdev.
 
           If unsure, say N.
 
 config FIND_BIT_BENCHMARK
         tristate "Test find_bit functions"
         help
           This builds the "test_find_bit" module that measure find_*_bit()
           functions performance.
 
           If unsure, say N.
 
 config TEST_FIRMWARE
         tristate "Test firmware loading via userspace interface"
         depends on FW_LOADER
         help
           This builds the "test_firmware" module that creates a userspace
           interface for testing firmware loading. This can be used to
           control the triggering of firmware loading without needing an
           actual firmware-using device. The contents can be rechecked by
           userspace.
 
           If unsure, say N.
 
 config TEST_SYSCTL
         tristate "sysctl test driver"
         depends on PROC_SYSCTL
         help
           This builds the "test_sysctl" module. This driver enables to test the
           proc sysctl interfaces available to drivers safely without affecting
           production knobs which might alter system functionality.
 
           If unsure, say N.
 
 config BITFIELD_KUNIT
         tristate "KUnit test bitfield functions at runtime" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Enable this option to test the bitfield functions at boot.
 
           KUnit tests run during boot and output the results to the debug log
           in TAP format (http://testanything.org/). Only useful for kernel devs
           running the KUnit test harness, and not intended for inclusion into a
           production build.
 
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config CHECKSUM_KUNIT
         tristate "KUnit test checksum functions at runtime" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Enable this option to test the checksum functions at boot.
 
           KUnit tests run during boot and output the results to the debug log
           in TAP format (http://testanything.org/). Only useful for kernel devs
           running the KUnit test harness, and not intended for inclusion into a
           production build.
 
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config HASH_KUNIT_TEST
         tristate "KUnit Test for integer hash functions" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Enable this option to test the kernel's string (<linux/stringhash.h>), and
           integer (<linux/hash.h>) hash functions on boot.
 
           KUnit tests run during boot and output the results to the debug log
           in TAP format (https://testanything.org/). Only useful for kernel devs
           running the KUnit test harness, and not intended for inclusion into a
           production build.
 
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           This is intended to help people writing architecture-specific
           optimized versions. If unsure, say N.
 
 config RESOURCE_KUNIT_TEST
         tristate "KUnit test for resource API" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds the resource API unit test.
           Tests the logic of API provided by resource.c and ioport.h.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config SYSCTL_KUNIT_TEST
         tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds the proc sysctl unit test, which runs on boot.
           Tests the API contract and implementation correctness of sysctl.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config LIST_KUNIT_TEST
         tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds the linked list KUnit test suite.
           It tests that the API and basic functionality of the list_head type
           and associated macros.
 
           KUnit tests run during boot and output the results to the debug log
           in TAP format (https://testanything.org/). Only useful for kernel devs
           running the KUnit test harness, and not intended for inclusion into a
           production build.
 
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config HASHTABLE_KUNIT_TEST
         tristate "KUnit Test for Kernel Hashtable structures" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds the hashtable KUnit test suite.
           It tests the basic functionality of the API defined in
           include/linux/hashtable.h. For more information on KUnit and
           unit tests in general please refer to the KUnit documentation
           in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config LINEAR_RANGES_TEST
         tristate "KUnit test for linear_ranges"
         depends on KUNIT
         select LINEAR_RANGES
         help
           This builds the linear_ranges unit test, which runs on boot.
           Tests the linear_ranges logic correctness.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config CMDLINE_KUNIT_TEST
         tristate "KUnit test for cmdline API" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds the cmdline API unit test.
           Tests the logic of API provided by cmdline.c.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config BITS_TEST
         tristate "KUnit test for bits.h" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds the bits unit test.
           Tests the logic of macros defined in bits.h.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config SLUB_KUNIT_TEST
         tristate "KUnit test for SLUB cache error detection" if !KUNIT_ALL_TESTS
         depends on SLUB_DEBUG && KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds SLUB allocator unit test.
           Tests SLUB cache debugging functionality.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config RATIONAL_KUNIT_TEST
         tristate "KUnit test for rational.c" if !KUNIT_ALL_TESTS
         depends on KUNIT && RATIONAL
         default KUNIT_ALL_TESTS
         help
           This builds the rational math unit test.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config MEMCPY_KUNIT_TEST
         tristate "Test memcpy(), memmove(), and memset() functions at runtime" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Builds unit tests for memcpy(), memmove(), and memset() functions.
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config IS_SIGNED_TYPE_KUNIT_TEST
         tristate "Test is_signed_type() macro" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Builds unit tests for the is_signed_type() macro.
 
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config OVERFLOW_KUNIT_TEST
         tristate "Test check_*_overflow() functions at runtime" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Builds unit tests for the check_*_overflow(), size_*(), allocation, and
           related functions.
 
           For more information on KUnit and unit tests in general please refer
           to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 config STACKINIT_KUNIT_TEST
         tristate "Test level of stack variable initialization" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Test if the kernel is zero-initializing stack variables and
           padding. Coverage is controlled by compiler flags,
           CONFIG_INIT_STACK_ALL_PATTERN, CONFIG_INIT_STACK_ALL_ZERO,
           CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
           or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
 
 config FORTIFY_KUNIT_TEST
         tristate "Test fortified str*() and mem*() function internals at runtime" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Builds unit tests for checking internals of FORTIFY_SOURCE as used
           by the str*() and mem*() family of functions. For testing runtime
           traps of FORTIFY_SOURCE, see LKDTM's "FORTIFY_*" tests.
 
 config HW_BREAKPOINT_KUNIT_TEST
         bool "Test hw_breakpoint constraints accounting" if !KUNIT_ALL_TESTS
         depends on HAVE_HW_BREAKPOINT
         depends on KUNIT=y
         default KUNIT_ALL_TESTS
         help
           Tests for hw_breakpoint constraints accounting.
 
           If unsure, say N.
 
 config SIPHASH_KUNIT_TEST
         tristate "Perform selftest on siphash functions" if !KUNIT_ALL_TESTS
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           Enable this option to test the kernel's siphash (<linux/siphash.h>) hash
           functions on boot (or module load).
 
           This is intended to help people writing architecture-specific
           optimized versions.  If unsure, say N.
 
 config USERCOPY_KUNIT_TEST
         tristate "KUnit Test for user/kernel boundary protections"
         depends on KUNIT
         default KUNIT_ALL_TESTS
         help
           This builds the "usercopy_kunit" module that runs sanity checks
           on the copy_to/from_user infrastructure, making sure basic
           user/kernel boundary testing is working.
 
 config TEST_UDELAY
         tristate "udelay test driver"
         help
           This builds the "udelay_test" module that helps to make sure
           that udelay() is working properly.
 
           If unsure, say N.
 
 config TEST_STATIC_KEYS
         tristate "Test static keys"
         depends on m
         help
           Test the static key interfaces.
 
           If unsure, say N.
 
 config TEST_DYNAMIC_DEBUG
         tristate "Test DYNAMIC_DEBUG"
         depends on DYNAMIC_DEBUG
         help
           This module registers a tracer callback to count enabled
           pr_debugs in a 'do_debugging' function, then alters their
           enablements, calls the function, and compares counts.
 
           If unsure, say N.
 
 config TEST_KMOD
         tristate "kmod stress tester"
         depends on m
         depends on NETDEVICES && NET_CORE && INET # for TUN
         depends on BLOCK
         depends on PAGE_SIZE_LESS_THAN_256KB # for BTRFS
         select TEST_LKM
         select XFS_FS
         select TUN
         select BTRFS_FS
         help
           Test the kernel's module loading mechanism: kmod. kmod implements
           support to load modules using the Linux kernel's usermode helper.
           This test provides a series of tests against kmod.
 
           Although technically you can either build test_kmod as a module or
           into the kernel we disallow building it into the kernel since
           it stress tests request_module() and this will very likely cause
           some issues by taking over precious threads available from other
           module load requests, ultimately this could be fatal.
 
           To run tests run:
 
           tools/testing/selftests/kmod/kmod.sh --help
 
           If unsure, say N.
 
 config TEST_DEBUG_VIRTUAL
         tristate "Test CONFIG_DEBUG_VIRTUAL feature"
         depends on DEBUG_VIRTUAL
         help
           Test the kernel's ability to detect incorrect calls to
           virt_to_phys() done against the non-linear part of the
           kernel's virtual address map.
 
           If unsure, say N.
 
 config TEST_MEMCAT_P
         tristate "Test memcat_p() helper function"
         help
           Test the memcat_p() helper for correctly merging two
           pointer arrays together.
 
           If unsure, say N.
 
 config TEST_OBJAGG
         tristate "Perform selftest on object aggreration manager"
         default n
         depends on OBJAGG
         help
           Enable this option to test object aggregation manager on boot
           (or module load).
 
 config TEST_MEMINIT
         tristate "Test heap/page initialization"
         help
           Test if the kernel is zero-initializing heap and page allocations.
           This can be useful to test init_on_alloc and init_on_free features.
 
           If unsure, say N.
 
 config TEST_HMM
         tristate "Test HMM (Heterogeneous Memory Management)"
         depends on TRANSPARENT_HUGEPAGE
         depends on DEVICE_PRIVATE
         select HMM_MIRROR
         select MMU_NOTIFIER
         help
           This is a pseudo device driver solely for testing HMM.
           Say M here if you want to build the HMM test module.
           Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
 
           If unsure, say N.
 
 config TEST_FREE_PAGES
         tristate "Test freeing pages"
         help
           Test that a memory leak does not occur due to a race between
           freeing a block of pages and a speculative page reference.
           Loading this module is safe if your kernel has the bug fixed.
           If the bug is not fixed, it will leak gigabytes of memory and
           probably OOM your system.
 
 config TEST_FPU
         tristate "Test floating point operations in kernel space"
         depends on ARCH_HAS_KERNEL_FPU_SUPPORT && !KCOV_INSTRUMENT_ALL
         help
           Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
           which will trigger a sequence of floating point operations. This is used
           for self-testing floating point control register setting in
           kernel_fpu_begin().
 
           If unsure, say N.
 
 config TEST_CLOCKSOURCE_WATCHDOG
         tristate "Test clocksource watchdog in kernel space"
         depends on CLOCKSOURCE_WATCHDOG
         help
           Enable this option to create a kernel module that will trigger
           a test of the clocksource watchdog.  This module may be loaded
           via modprobe or insmod in which case it will run upon being
           loaded, or it may be built in, in which case it will run
           shortly after boot.
 
           If unsure, say N.
 
 config TEST_OBJPOOL
         tristate "Test module for correctness and stress of objpool"
         default n
         depends on m && DEBUG_KERNEL
         help
           This builds the "test_objpool" module that should be used for
           correctness verification and concurrent testings of objects
           allocation and reclamation.
 
           If unsure, say N.
 
 endif # RUNTIME_TESTING_MENU
 
 config ARCH_USE_MEMTEST
         bool
         help
           An architecture should select this when it uses early_memtest()
           during boot process.
 
 config MEMTEST
         bool "Memtest"
         depends on ARCH_USE_MEMTEST
         help
           This option adds a kernel parameter 'memtest', which allows memtest
           to be set and executed.
                 memtest=0, mean disabled; -- default
                 memtest=1, mean do 1 test pattern;
                 ...
                 memtest=17, mean do 17 test patterns.
           If you are unsure how to answer this question, answer N.
 
 
 
 config HYPERV_TESTING
         bool "Microsoft Hyper-V driver testing"
         default n
         depends on HYPERV && DEBUG_FS
         help
           Select this option to enable Hyper-V vmbus testing.
 
 endmenu # "Kernel Testing and Coverage"
 
 menu "Rust hacking"
 
 config RUST_DEBUG_ASSERTIONS
         bool "Debug assertions"
         depends on RUST
         help
           Enables rustc's `-Cdebug-assertions` codegen option.
 
           This flag lets you turn `cfg(debug_assertions)` conditional
           compilation on or off. This can be used to enable extra debugging
           code in development but not in production. For example, it controls
           the behavior of the standard library's `debug_assert!` macro.
 
           Note that this will apply to all Rust code, including `core`.
 
           If unsure, say N.
 
 config RUST_OVERFLOW_CHECKS
         bool "Overflow checks"
         default y
         depends on RUST
         help
           Enables rustc's `-Coverflow-checks` codegen option.
 
           This flag allows you to control the behavior of runtime integer
           overflow. When overflow-checks are enabled, a Rust panic will occur
           on overflow.
 
           Note that this will apply to all Rust code, including `core`.
 
           If unsure, say Y.
 
 config RUST_BUILD_ASSERT_ALLOW
         bool "Allow unoptimized build-time assertions"
         depends on RUST
         help
           Controls how are `build_error!` and `build_assert!` handled during build.
 
           If calls to them exist in the binary, it may indicate a violated invariant
           or that the optimizer failed to verify the invariant during compilation.
 
           This should not happen, thus by default the build is aborted. However,
           as an escape hatch, you can choose Y here to ignore them during build
           and let the check be carried at runtime (with `panic!` being called if
           the check fails).
 
           If unsure, say N.
 
 config RUST_KERNEL_DOCTESTS
         bool "Doctests for the `kernel` crate" if !KUNIT_ALL_TESTS
         depends on RUST && KUNIT=y
         default KUNIT_ALL_TESTS
         help
           This builds the documentation tests of the `kernel` crate
           as KUnit tests.
 
           For more information on KUnit and unit tests in general,
           please refer to the KUnit documentation in Documentation/dev-tools/kunit/.
 
           If unsure, say N.
 
 endmenu # "Rust"
 
 endmenu # Kernel hacking

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