| # 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 PRINTK_EXECUTION_CTX | |
| bool | |
| depends on PRINTK | |
| help | |
| This option extends struct printk_info to include extra execution | |
| context in printk, such as task name and CPU number from where the | |
| message originated. This is useful for correlating printk messages | |
| with specific execution contexts. | |
| This is automatically enabled when a console driver that supports | |
| execution context is selected. | |
| 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 jiffy" 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. | |
| config DEBUG_BUGVERBOSE_DETAILED | |
| bool "Verbose WARN_ON_ONCE() reporting (adds 100K)" if DEBUG_BUGVERBOSE | |
| help | |
| Say Y here to make WARN_ON_ONCE() output the condition string of the | |
| warning, in addition to the file name and line number. | |
| This helps debugging, but costs about 100K of memory. | |
| Say N if unsure. | |
| 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 || (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. | |
| Users of dpkg-deb via debian/rules 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 or DPKG_DEB_COMPRESSOR_TYPE 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 PAHOLE_VERSION >= 122 | |
| # 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 requires pahole v1.22 or later, which will convert | |
| DWARF type info into equivalent deduplicated BTF type info. | |
| 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 | |
| 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/process/debugging/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 !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" | |
| 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. 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, | |
| __initdata, and so on (see the full list in include/linux/init.h). | |
| This directs the toolchain to place code/data in specific sections. | |
| The section mismatch analysis is always performed after a full | |
| kernel build, and enabling this option causes the option | |
| -fno-inline-functions-called-once to be added to gcc commands. | |
| However, 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 OBJTOOL_WERROR | |
| bool "Upgrade objtool warnings to errors" | |
| depends on OBJTOOL && !COMPILE_TEST | |
| help | |
| Fail the build on objtool warnings. | |
| Objtool warnings can indicate kernel instability, including boot | |
| failures. This option is highly recommended. | |
| If unsure, say Y. | |
| 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 BUILTIN_MODULE_RANGES | |
| bool "Generate address range information for builtin modules" | |
| depends on !LTO | |
| depends on VMLINUX_MAP | |
| help | |
| When modules are built into the kernel, there will be no module name | |
| associated with its symbols in /proc/kallsyms. Tracers may want to | |
| identify symbols by module name and symbol name regardless of whether | |
| the module is configured as loadable or not. | |
| This option generates modules.builtin.ranges in the build tree with | |
| offset ranges (per ELF section) for the module(s) they belong to. | |
| It also records an anchor symbol to determine the load address of the | |
| section. | |
| 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. | |
| config WARN_CONTEXT_ANALYSIS | |
| bool "Compiler context-analysis warnings" | |
| depends on CC_IS_CLANG && CLANG_VERSION >= 230000 | |
| # Branch profiling re-defines "if", which messes with the compiler's | |
| # ability to analyze __cond_acquires(..), resulting in false positives. | |
| depends on !TRACE_BRANCH_PROFILING | |
| default y | |
| help | |
| Context Analysis is a language extension, which enables statically | |
| checking that required contexts are active (or inactive) by acquiring | |
| and releasing user-definable "context locks". | |
| Clang's name of the feature is "Thread Safety Analysis". Requires | |
| Clang 23 or later. | |
| Produces warnings by default. Select CONFIG_WERROR if you wish to | |
| turn these warnings into errors. | |
| For more details, see Documentation/dev-tools/context-analysis.rst. | |
| config WARN_CONTEXT_ANALYSIS_ALL | |
| bool "Enable context analysis for all source files" | |
| depends on WARN_CONTEXT_ANALYSIS | |
| depends on EXPERT && !COMPILE_TEST | |
| help | |
| Enable tree-wide context analysis. This is likely to produce a | |
| large number of false positives - enable at your own risk. | |
| If unsure, say N. | |
| 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,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_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 PREEMPT_COUNT || !DEFERRED_STRUCT_PAGE_INIT | |
| 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_VFS | |
| bool "Debug VFS" | |
| depends on DEBUG_KERNEL | |
| help | |
| Enable this to turn on extended checks in the VFS layer that may impact | |
| performance. | |
| If unsure, say N. | |
| 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 MMU | |
| 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_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 | |
| int "Panic (Reboot) On Soft Lockups" | |
| depends on SOFTLOCKUP_DETECTOR | |
| default 0 | |
| help | |
| Set to a non-zero value N to enable the kernel to panic on "soft | |
| lockups", which are bugs that cause the kernel to loop in kernel | |
| mode for more than (N * 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 0 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 | |
| int "Number of hung tasks to trigger kernel panic" | |
| depends on DETECT_HUNG_TASK | |
| default 0 | |
| help | |
| When set to a non-zero value, a kernel panic will be triggered | |
| if the number of hung tasks found during a single scan reaches | |
| this value. | |
| 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 0 if unsure. | |
| config DETECT_HUNG_TASK_BLOCKER | |
| bool "Dump Hung Tasks Blocker" | |
| depends on DETECT_HUNG_TASK | |
| depends on !PREEMPT_RT | |
| default y | |
| help | |
| Say Y here to show the blocker task's stacktrace who acquires | |
| the mutex lock which "hung tasks" are waiting. | |
| This will add overhead a bit but shows suspicious tasks and | |
| call trace if it comes from waiting a mutex. | |
| 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 BOOTPARAM_WQ_STALL_PANIC | |
| int "Panic on Nth workqueue stall" | |
| default 0 | |
| range 0 100 | |
| depends on WQ_WATCHDOG | |
| help | |
| Set the number of workqueue stalls to trigger a kernel panic. | |
| A workqueue stall occurs when a worker pool doesn't make forward | |
| progress on a pending work item for over 30 seconds (configurable | |
| using the workqueue.watchdog_thresh parameter). | |
| If n = 0, the kernel will not panic on stall. If n > 0, the kernel | |
| will panic after n stall warnings. | |
| The panic can be used in combination with panic_timeout, | |
| to cause the system to reboot automatically after a | |
| stall has been detected. This feature is useful for | |
| high-availability systems that have uptime guarantees and | |
| where a stall must be resolved ASAP. | |
| This setting can be overridden at runtime via the | |
| workqueue.panic_on_stall kernel parameter. | |
| 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_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_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. | |
| config DEBUG_ATOMIC | |
| bool "Debug atomic variables" | |
| depends on DEBUG_KERNEL | |
| help | |
| If you say Y here then the kernel will add a runtime alignment check | |
| to atomic accesses. Useful for architectures that do not have trap on | |
| mis-aligned access. | |
| This option has potentially significant overhead. | |
| config DEBUG_ATOMIC_LARGEST_ALIGN | |
| bool "Check alignment only up to __aligned_largest" | |
| depends on DEBUG_ATOMIC | |
| help | |
| If you say Y here then the check for natural alignment of | |
| atomic accesses will be constrained to the compiler's largest | |
| alignment for scalar types. | |
| 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" if !ARCH_SUPPORTS_RT | |
| depends on PROVE_LOCKING | |
| default y if ARCH_SUPPORTS_RT | |
| help | |
| Enable the raw_spinlock vs. spinlock nesting checks which ensure | |
| that the lock nesting rules for PREEMPT_RT enabled kernels are | |
| not violated. | |
| 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 "Size for MAX_LOCKDEP_ENTRIES (as Nth power of 2)" | |
| depends on LOCKDEP && !LOCKDEP_SMALL | |
| range 10 24 | |
| default 15 | |
| help | |
| Try increasing this value if you hit "BUG: MAX_LOCKDEP_ENTRIES too low!" message. | |
| config LOCKDEP_CHAINS_BITS | |
| int "Size for MAX_LOCKDEP_CHAINS (as Nth power of 2)" | |
| depends on LOCKDEP && !LOCKDEP_SMALL | |
| range 10 21 | |
| default 16 | |
| help | |
| Try increasing this value if you hit "BUG: MAX_LOCKDEP_CHAINS too low!" message. | |
| config LOCKDEP_STACK_TRACE_BITS | |
| int "Size for MAX_STACK_TRACE_ENTRIES (as Nth power of 2)" | |
| depends on LOCKDEP && !LOCKDEP_SMALL | |
| range 10 26 | |
| default 21 if KASAN | |
| default 19 | |
| help | |
| Try increasing this value if you hit "BUG: MAX_STACK_TRACE_ENTRIES too low!" message. | |
| KASAN significantly increases stack trace consumption because its | |
| slab tracking interacts with lockdep's dependency validation under | |
| PREEMPT_FULL, creating a feedback loop. The higher default when | |
| KASAN is enabled costs ~12MB extra, which is negligible compared to | |
| KASAN's own shadow memory overhead. | |
| config LOCKDEP_STACK_TRACE_HASH_BITS | |
| int "Size for STACK_TRACE_HASH_SIZE (as Nth power of 2)" | |
| depends on LOCKDEP && !LOCKDEP_SMALL | |
| range 10 26 | |
| default 16 if KASAN | |
| default 14 | |
| help | |
| Try increasing this value if you need large STACK_TRACE_HASH_SIZE. | |
| config LOCKDEP_CIRCULAR_QUEUE_BITS | |
| int "Size for elements in circular_queue struct (as Nth power of 2)" | |
| depends on LOCKDEP | |
| range 10 26 | |
| 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 SMP | |
| 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 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 || S390 | |
| 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 FAIL_SKB_REALLOC | |
| bool "Fault-injection capability forcing skb to reallocate" | |
| depends on FAULT_INJECTION_DEBUG_FS | |
| help | |
| Provide fault-injection capability that forces the skb to be | |
| reallocated, catching possible invalid pointers to the skb. | |
| For more information, check | |
| Documentation/fault-injection/fault-injection.rst | |
| 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 KCOV | |
| bool "Code coverage for fuzzing" | |
| depends on ARCH_HAS_KCOV | |
| depends on !ARCH_WANTS_NO_INSTR || HAVE_NOINSTR_HACK || \ | |
| GCC_VERSION >= 120000 || CC_IS_CLANG | |
| select DEBUG_FS | |
| 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. | |
| config KCOV_SELFTEST | |
| bool "Perform short selftests on boot" | |
| depends on KCOV | |
| help | |
| Run short KCOV coverage collection selftests on boot. | |
| On test failure, causes the kernel to panic. Recommended to be | |
| enabled, ensuring critical functionality works as intended. | |
| 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_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_MULDIV64 | |
| tristate "mul_u64_u64_div_u64() test" | |
| depends on DEBUG_KERNEL || m | |
| help | |
| Enable this to turn on 'mul_u64_u64_div_u64()' 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 PRINTF_KUNIT_TEST | |
| tristate "KUnit test printf() family of functions at runtime" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| Enable this option to test the printf functions at runtime. | |
| If unsure, say N. | |
| config SCANF_KUNIT_TEST | |
| tristate "KUnit test scanf() family of functions at runtime" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| Enable this option to test the scanf functions at runtime. | |
| If unsure, say N. | |
| config SEQ_BUF_KUNIT_TEST | |
| tristate "KUnit test for seq_buf" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This builds unit tests for the seq_buf library. | |
| If unsure, say N. | |
| 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 STRING_KUNIT_BENCH | |
| bool "Benchmark string functions at runtime" | |
| depends on STRING_KUNIT_TEST | |
| help | |
| Enable performance measurement for string functions. | |
| This measures the execution efficiency of string functions | |
| during the KUnit test run. | |
| If unsure, say N. | |
| config FFS_KUNIT_TEST | |
| tristate "KUnit test ffs-family functions at runtime" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This builds KUnit tests for ffs-family bit manipulation functions | |
| including ffs(), __ffs(), fls(), __fls(), fls64(), and __ffs64(). | |
| These tests validate mathematical correctness, edge case handling, | |
| and cross-architecture consistency of bit scanning functions. | |
| For more information on KUnit and unit tests in general, | |
| please refer to Documentation/dev-tools/kunit/. | |
| config TEST_KSTRTOX | |
| tristate "Test kstrto*() 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_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_MISC_MINOR | |
| bool "miscdevice KUnit test" if !KUNIT_ALL_TESTS | |
| depends on KUNIT=y | |
| default KUNIT_ALL_TESTS | |
| help | |
| Kunit test for miscdevice API, specially its behavior in respect to | |
| static and dynamic minor numbers. | |
| 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 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_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 | |
| 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_WORKQUEUE | |
| tristate "Test module for stress/performance analysis of workqueue" | |
| depends on m | |
| default n | |
| help | |
| This builds the "test_workqueue" module for benchmarking | |
| workqueue throughput under contention. Useful for evaluating | |
| affinity scope changes (e.g., cache_shard vs cache). | |
| The test drives sysfs to switch affinity scopes, so it must be | |
| loaded after userspace has mounted sysfs; building it in (=y) | |
| would run module_init before /sys is available. | |
| 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 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 FIND_BIT_BENCHMARK_RUST | |
| tristate "Test find_bit functions in Rust" | |
| depends on RUST | |
| help | |
| This builds the "find_bit_benchmark_rust" module. It is a micro | |
| benchmark that measures the performance of Rust functions that | |
| correspond to the find_*_bit() operations in C. It follows the | |
| FIND_BIT_BENCHMARK closely but will in general not yield same | |
| numbers due to extra bounds checks and overhead of foreign | |
| function calls. | |
| 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 BITOPS_KUNIT | |
| tristate "KUnit test for bitops" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test for the bitops library | |
| which provides functions for bit operations. | |
| Note that this is derived from the original test_bitops module. | |
| For micro-benchmarks and compiler warning checks, enable TEST_BITOPS. | |
| 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 UTIL_MACROS_KUNIT | |
| tristate "KUnit test util_macros.h functions at runtime" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| Enable this option to test the util_macros.h function 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 | |
| select GET_FREE_REGION | |
| 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 KFIFO_KUNIT_TEST | |
| tristate "KUnit Test for the generic kernel FIFO implementation" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This builds the generic FIFO implementation KUnit test suite. | |
| It tests that the API and basic functionality of the kfifo type | |
| and associated macros. | |
| 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 LIST_PRIVATE_KUNIT_TEST | |
| tristate "KUnit Test for Kernel Private Linked-list structures" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This builds the KUnit test for the private linked-list primitives | |
| defined in include/linux/list_private.h. | |
| These primitives allow manipulation of list_head members that are | |
| marked as private and require special accessors (ACCESS_PRIVATE) | |
| to strip qualifiers or handle encapsulation. | |
| 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 CONTEXT_ANALYSIS_TEST | |
| bool "Compiler context-analysis warnings test" | |
| depends on EXPERT | |
| help | |
| This builds the test for compiler-based context analysis. The test | |
| does not add executable code to the kernel, but is meant to test that | |
| common patterns supported by the analysis do not result in false | |
| positive warnings. | |
| When adding support for new context locks, it is strongly recommended | |
| to add supported patterns to this test. | |
| If unsure, say N. | |
| config LIVEUPDATE_TEST | |
| bool "Live Update Kernel Test" | |
| default n | |
| depends on LIVEUPDATE | |
| help | |
| Enable a built-in kernel test module for the Live Update | |
| Orchestrator. | |
| This module validates the File-Lifecycle-Bound subsystem by | |
| registering a set of mock FLB objects with any real file handlers | |
| that support live update (such as the memfd handler). | |
| When live update operations are performed, this test module will | |
| output messages to the kernel log (dmesg), confirming that its | |
| registration and various callback functions (preserve, retrieve, | |
| finish, etc.) are being invoked correctly. | |
| This is a debugging and regression testing tool for developers | |
| working on the Live Update subsystem. It should not be enabled in | |
| production kernels. | |
| 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 BASE64_KUNIT | |
| tristate "KUnit test for base64 decoding and encoding" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This builds the base64 unit tests. | |
| The tests cover the encoding and decoding logic of Base64 functions | |
| in the kernel. | |
| In addition to correctness checks, simple performance benchmarks | |
| for both encoding and decoding are also included. | |
| 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 bit functions and macros" 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 SHDI3_KUNIT_TEST | |
| tristate "KUnit test for __ashldi3(), __ashrdi3(), and __lshrdi3()" | |
| depends on KUNIT | |
| depends on ARM || XTENSA || MICROBLAZE || ((RISCV || SPARC) && !64BIT) | |
| help | |
| This builds the unit test for __ashldi3(), __ashrdi3(), and | |
| __lshrdi3() helper functions used to implement 64-bit arithmetic | |
| shift left, arithmetic shift right and logical shift right, | |
| respectively, on a 32-bit CPUs. | |
| 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 MIN_HEAP_KUNIT_TEST | |
| tristate "Min heap test" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test suite for the min heap library | |
| which provides functions for creating and managing min heaps. | |
| The test suite checks the functionality of the min heap library. | |
| 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 RANDSTRUCT_KUNIT_TEST | |
| tristate "Test randstruct structure layout randomization at runtime" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| Builds unit tests for the checking CONFIG_RANDSTRUCT=y, which | |
| randomizes structure layouts. | |
| 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 or CONFIG_INIT_STACK_ALL_ZERO. | |
| 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 LONGEST_SYM_KUNIT_TEST | |
| tristate "Test the longest symbol possible" if !KUNIT_ALL_TESTS | |
| depends on KUNIT && KPROBES | |
| depends on !CALL_PADDING && !CFI && !GCOV_KERNEL | |
| default KUNIT_ALL_TESTS | |
| help | |
| Tests the longest symbol possible | |
| If unsure, say N. | |
| 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. | |
| source "lib/crypto/tests/Kconfig" | |
| 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 BLACKHOLE_DEV_KUNIT_TEST | |
| tristate "Test blackhole netdev functionality" if !KUNIT_ALL_TESTS | |
| depends on NET | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This builds the "blackhole_dev_kunit" module that validates the | |
| data path through this blackhole netdev. | |
| If unsure, say N. | |
| 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 | |
| select TEST_LKM | |
| 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_RUNTIME | |
| bool | |
| config TEST_RUNTIME_MODULE | |
| bool | |
| config TEST_KALLSYMS | |
| tristate "module kallsyms find_symbol() test" | |
| depends on m | |
| select TEST_RUNTIME | |
| select TEST_RUNTIME_MODULE | |
| select TEST_KALLSYMS_A | |
| select TEST_KALLSYMS_B | |
| select TEST_KALLSYMS_C | |
| select TEST_KALLSYMS_D | |
| help | |
| This allows us to stress test find_symbol() through the kallsyms | |
| used to place symbols on the kernel ELF kallsyms and modules kallsyms | |
| where we place kernel symbols such as exported symbols. | |
| We have four test modules: | |
| A: has KALLSYSMS_NUMSYMS exported symbols | |
| B: uses one of A's symbols | |
| C: adds KALLSYMS_SCALE_FACTOR * KALLSYSMS_NUMSYMS exported | |
| D: adds 2 * the symbols than C | |
| We stress test find_symbol() through two means: | |
| 1) Upon load of B it will trigger simplify_symbols() to look for the | |
| one symbol it uses from the module A with tons of symbols. This is an | |
| indirect way for us to have B call resolve_symbol_wait() upon module | |
| load. This will eventually call find_symbol() which will eventually | |
| try to find the symbols used with find_exported_symbol_in_section(). | |
| find_exported_symbol_in_section() uses bsearch() so a binary search | |
| for each symbol. Binary search will at worst be O(log(n)) so the | |
| larger TEST_MODULE_KALLSYSMS the worse the search. | |
| 2) The selftests should load C first, before B. Upon B's load towards | |
| the end right before we call module B's init routine we get | |
| complete_formation() called on the module. That will first check | |
| for duplicate symbols with the call to verify_exported_symbols(). | |
| That is when we'll force iteration on module C's insane symbol list. | |
| Since it has 10 * KALLSYMS_NUMSYMS it means we can first test | |
| just loading B without C. The amount of time it takes to load C Vs | |
| B can give us an idea of the impact growth of the symbol space and | |
| give us projection. Module A only uses one symbol from B so to allow | |
| this scaling in module C to be proportional, if it used more symbols | |
| then the first test would be doing more and increasing just the | |
| search space would be slightly different. The last module, module D | |
| will just increase the search space by twice the number of symbols in | |
| C so to allow for full projects. | |
| tools/testing/selftests/module/find_symbol.sh | |
| The current defaults will incur a build delay of about 7 minutes | |
| on an x86_64 with only 8 cores. Enable this only if you want to | |
| stress test find_symbol() with thousands of symbols. At the same | |
| time this is also useful to test building modules with thousands of | |
| symbols, and if BTF is enabled this also stress tests adding BTF | |
| information for each module. Currently enabling many more symbols | |
| will segfault the build system. | |
| If unsure, say N. | |
| if TEST_KALLSYMS | |
| config TEST_KALLSYMS_A | |
| tristate | |
| depends on m | |
| config TEST_KALLSYMS_B | |
| tristate | |
| depends on m | |
| config TEST_KALLSYMS_C | |
| tristate | |
| depends on m | |
| config TEST_KALLSYMS_D | |
| tristate | |
| depends on m | |
| choice | |
| prompt "Kallsym test range" | |
| default TEST_KALLSYMS_LARGE | |
| help | |
| Selecting something other than "Fast" will enable tests which slow | |
| down the build and may crash your build. | |
| config TEST_KALLSYMS_FAST | |
| bool "Fast builds" | |
| help | |
| You won't really be testing kallsysms, so this just helps fast builds | |
| when allmodconfig is used.. | |
| config TEST_KALLSYMS_LARGE | |
| bool "Enable testing kallsyms with large exports" | |
| help | |
| This will enable larger number of symbols. This will slow down | |
| your build considerably. | |
| config TEST_KALLSYMS_MAX | |
| bool "Known kallsysms limits" | |
| help | |
| This will enable exports to the point we know we'll start crashing | |
| builds. | |
| endchoice | |
| config TEST_KALLSYMS_NUMSYMS | |
| int "test kallsyms number of symbols" | |
| range 2 10000 | |
| default 2 if TEST_KALLSYMS_FAST | |
| default 100 if TEST_KALLSYMS_LARGE | |
| default 10000 if TEST_KALLSYMS_MAX | |
| help | |
| The number of symbols to create on TEST_KALLSYMS_A, only one of which | |
| module TEST_KALLSYMS_B will use. This also will be used | |
| for how many symbols TEST_KALLSYMS_C will have, scaled up by | |
| TEST_KALLSYMS_SCALE_FACTOR. Note that setting this to 10,000 will | |
| trigger a segfault today, don't use anything close to it unless | |
| you are aware that this should not be used for automated build tests. | |
| config TEST_KALLSYMS_SCALE_FACTOR | |
| int "test kallsyms scale factor" | |
| default 8 | |
| help | |
| How many more unusued symbols will TEST_KALLSYSMS_C have than | |
| TEST_KALLSYMS_A. If 8, then module C will have 8 * syms | |
| than module A. Then TEST_KALLSYMS_D will have double the amount | |
| of symbols than C so to allow projections. | |
| endif # TEST_KALLSYMS | |
| 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. | |
| config TEST_KEXEC_HANDOVER | |
| bool "Test for Kexec HandOver" | |
| default n | |
| depends on KEXEC_HANDOVER | |
| help | |
| This option enables test for Kexec HandOver (KHO). | |
| The test consists of two parts: saving kernel data before kexec and | |
| restoring the data after kexec and verifying that it was properly | |
| handed over. This test module creates and saves data on the boot of | |
| the first kernel and restores and verifies the data on the boot of | |
| kexec'ed kernel. | |
| For detailed documentation about KHO, see Documentation/core-api/kho. | |
| To run the test run: | |
| tools/testing/selftests/kho/vmtest.sh -h | |
| If unsure, say N. | |
| config RATELIMIT_KUNIT_TEST | |
| tristate "KUnit Test for correctness and stress of ratelimit" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This builds the "test_ratelimit" module that should be used | |
| for correctness verification and concurrent testings of rate | |
| limiting. | |
| If unsure, say N. | |
| config UUID_KUNIT_TEST | |
| tristate "KUnit test for UUID" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test suite for the uuid library, | |
| which provides functions for generating and parsing UUID and GUID. | |
| The test suite checks parsing of UUID and GUID strings. | |
| If unsure, say N. | |
| config INT_POW_KUNIT_TEST | |
| tristate "Integer exponentiation (int_pow) test" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test suite for the int_pow function, | |
| which performs integer exponentiation. The test suite is designed to | |
| verify that the implementation of int_pow correctly computes the power | |
| of a given base raised to a given exponent. | |
| Enabling this option will include tests that check various scenarios | |
| and edge cases to ensure the accuracy and reliability of the exponentiation | |
| function. | |
| If unsure, say N | |
| config INT_SQRT_KUNIT_TEST | |
| tristate "Integer square root test" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test suite for the int_sqrt() function, | |
| which performs square root calculation. The test suite checks | |
| various scenarios, including edge cases, to ensure correctness. | |
| Enabling this option will include tests that check various scenarios | |
| and edge cases to ensure the accuracy and reliability of the square root | |
| function. | |
| If unsure, say N | |
| config INT_LOG_KUNIT_TEST | |
| tristate "Integer log (int_log) test" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test suite for the int_log library, which | |
| provides two functions to compute the integer logarithm in base 2 and | |
| base 10, called respectively as intlog2 and intlog10. | |
| If unsure, say N | |
| config GCD_KUNIT_TEST | |
| tristate "Greatest common divisor test" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test suite for the gcd() function, | |
| which computes the greatest common divisor of two numbers. | |
| This test suite verifies the correctness of gcd() across various | |
| scenarios, including edge cases. | |
| If unsure, say N | |
| config PRIME_NUMBERS_KUNIT_TEST | |
| tristate "Prime number generator test" if !KUNIT_ALL_TESTS | |
| depends on KUNIT | |
| depends on PRIME_NUMBERS | |
| default KUNIT_ALL_TESTS | |
| help | |
| This option enables the KUnit test suite for the {is,next}_prime_number | |
| functions. | |
| Enabling this option will include tests that compare the prime number | |
| generator functions against a brute force implementation. | |
| If unsure, say N | |
| config GLOB_KUNIT_TEST | |
| tristate "Glob matching test" if !KUNIT_ALL_TESTS | |
| depends on GLOB | |
| depends on KUNIT | |
| default KUNIT_ALL_TESTS | |
| help | |
| Enable this option to test the glob functions at runtime. | |
| This test suite verifies the correctness of glob_match() across various | |
| scenarios, including edge cases. | |
| 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 `build_error!` and `build_assert!` are handled during the 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. | |
| config RUST_INLINE_HELPERS | |
| bool "Inline C helpers into Rust code (EXPERIMENTAL)" | |
| depends on RUST && RUSTC_CLANG_LLVM_COMPATIBLE | |
| depends on EXPERT | |
| depends on ARM64 || X86_64 | |
| depends on !UML | |
| help | |
| Inlines C helpers into Rust code using Link Time Optimization. | |
| If this option is enabled, C helper functions declared in | |
| rust/helpers/ are inlined into Rust code, which is helpful for | |
| performance of Rust code. This requires a matching LLVM version for | |
| Clang and rustc. | |
| If you are sure that you're using Clang and rustc with matching LLVM | |
| versions, say Y. Otherwise say N. | |
| endmenu # "Rust" | |
| endmenu # Kernel hacking |