| # 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 CONSOLE_LOGLEVEL_DEFAULT |
| int "Default console loglevel (1-15)" |
| range 1 15 |
| default "7" |
| help |
| Default loglevel to determine what will be printed on the console. |
| |
| Setting a default here is equivalent to passing in loglevel=<x> in |
| the kernel bootargs. loglevel=<x> continues to override whatever |
| value is specified here as well. |
| |
| Note: This does not affect the log level of un-prefixed printk() |
| usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT |
| option. |
| |
| config CONSOLE_LOGLEVEL_QUIET |
| int "quiet console loglevel (1-15)" |
| range 1 15 |
| default "4" |
| help |
| loglevel to use when "quiet" is passed on the kernel commandline. |
| |
| When "quiet" is passed on the kernel commandline this loglevel |
| will be used as the loglevel. IOW passing "quiet" will be the |
| equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>" |
| |
| config MESSAGE_LOGLEVEL_DEFAULT |
| int "Default message log level (1-7)" |
| range 1 7 |
| default "4" |
| help |
| Default log level for printk statements with no specified priority. |
| |
| This was hard-coded to KERN_WARNING since at least 2.6.10 but folks |
| that are auditing their logs closely may want to set it to a lower |
| priority. |
| |
| Note: This does not affect what message level gets printed on the console |
| by default. To change that, use loglevel=<x> in the kernel bootargs, |
| or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value. |
| |
| config BOOT_PRINTK_DELAY |
| bool "Delay each boot printk message by N milliseconds" |
| depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY |
| help |
| This build option allows you to read kernel boot messages |
| by inserting a short delay after each one. The delay is |
| specified in milliseconds on the kernel command line, |
| using "boot_delay=N". |
| |
| It is likely that you would also need to use "lpj=M" to preset |
| the "loops per jiffie" value. |
| See a previous boot log for the "lpj" value to use for your |
| system, and then set "lpj=M" before setting "boot_delay=N". |
| NOTE: Using this option may adversely affect SMP systems. |
| I.e., processors other than the first one may not boot up. |
| BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect |
| what it believes to be lockup conditions. |
| |
| config DYNAMIC_DEBUG |
| bool "Enable dynamic printk() support" |
| default n |
| depends on PRINTK |
| depends on (DEBUG_FS || PROC_FS) |
| select DYNAMIC_DEBUG_CORE |
| help |
| |
| Compiles debug level messages into the kernel, which would not |
| otherwise be available at runtime. These messages can then be |
| enabled/disabled based on various levels of scope - per source file, |
| function, module, format string, and line number. This mechanism |
| implicitly compiles in all pr_debug() and dev_dbg() calls, which |
| enlarges the kernel text size by about 2%. |
| |
| If a source file is compiled with DEBUG flag set, any |
| pr_debug() calls in it are enabled by default, but can be |
| disabled at runtime as below. Note that DEBUG flag is |
| turned on by many CONFIG_*DEBUG* options. |
| |
| Usage: |
| |
| Dynamic debugging is controlled via the 'dynamic_debug/control' file, |
| which is contained in the 'debugfs' filesystem or procfs. |
| Thus, the debugfs or procfs filesystem must first be mounted before |
| making use of this feature. |
| We refer the control file as: <debugfs>/dynamic_debug/control. This |
| file contains a list of the debug statements that can be enabled. The |
| format for each line of the file is: |
| |
| filename:lineno [module]function flags format |
| |
| filename : source file of the debug statement |
| lineno : line number of the debug statement |
| module : module that contains the debug statement |
| function : function that contains the debug statement |
| flags : '=p' means the line is turned 'on' for printing |
| format : the format used for the debug statement |
| |
| From a live system: |
| |
| nullarbor:~ # cat <debugfs>/dynamic_debug/control |
| # filename:lineno [module]function flags format |
| fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012" |
| fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012" |
| fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012" |
| |
| Example usage: |
| |
| // enable the message at line 1603 of file svcsock.c |
| nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > |
| <debugfs>/dynamic_debug/control |
| |
| // enable all the messages in file svcsock.c |
| nullarbor:~ # echo -n 'file svcsock.c +p' > |
| <debugfs>/dynamic_debug/control |
| |
| // enable all the messages in the NFS server module |
| nullarbor:~ # echo -n 'module nfsd +p' > |
| <debugfs>/dynamic_debug/control |
| |
| // enable all 12 messages in the function svc_process() |
| nullarbor:~ # echo -n 'func svc_process +p' > |
| <debugfs>/dynamic_debug/control |
| |
| // disable all 12 messages in the function svc_process() |
| nullarbor:~ # echo -n 'func svc_process -p' > |
| <debugfs>/dynamic_debug/control |
| |
| See Documentation/admin-guide/dynamic-debug-howto.rst for additional |
| information. |
| |
| config DYNAMIC_DEBUG_CORE |
| bool "Enable core function of dynamic debug support" |
| depends on PRINTK |
| depends on (DEBUG_FS || PROC_FS) |
| help |
| Enable core functional support of dynamic debug. It is useful |
| when you want to tie dynamic debug to your kernel modules with |
| DYNAMIC_DEBUG_MODULE defined for each of them, especially for |
| the case of embedded system where the kernel image size is |
| sensitive for people. |
| |
| config SYMBOLIC_ERRNAME |
| bool "Support symbolic error names in printf" |
| default y if PRINTK |
| help |
| If you say Y here, the kernel's printf implementation will |
| be able to print symbolic error names such as ENOSPC instead |
| of the number 28. It makes the kernel image slightly larger |
| (about 3KB), but can make the kernel logs easier to read. |
| |
| config DEBUG_BUGVERBOSE |
| bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT |
| depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE) |
| default y |
| help |
| Say Y here to make BUG() panics output the file name and line number |
| of the BUG call as well as the EIP and oops trace. This aids |
| debugging but costs about 70-100K of memory. |
| |
| endmenu # "printk and dmesg options" |
| |
| menu "Compile-time checks and compiler options" |
| |
| config DEBUG_INFO |
| bool "Compile the kernel with debug info" |
| depends on DEBUG_KERNEL && !COMPILE_TEST |
| help |
| If you say Y here the resulting kernel image 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. |
| Say Y here only if you plan to debug the kernel. |
| |
| If unsure, say N. |
| |
| 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. |
| |
| config DEBUG_INFO_COMPRESSED |
| bool "Compressed debugging information" |
| depends on $(cc-option,-gz=zlib) |
| depends on $(ld-option,--compress-debug-sections=zlib) |
| help |
| Compress the debug information using zlib. Requires GCC 5.0+ or Clang |
| 5.0+, binutils 2.26+, and zlib. |
| |
| Users of dpkg-deb via scripts/package/builddeb may find an increase in |
| size of their debug .deb packages with this config set, due to the |
| debug info being compressed with zlib, then the object files being |
| recompressed with a different compression scheme. But this is still |
| preferable to setting $KDEB_COMPRESS to "none" which would be even |
| larger. |
| |
| config DEBUG_INFO_SPLIT |
| bool "Produce split debuginfo in .dwo files" |
| depends on $(cc-option,-gsplit-dwarf) |
| 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_DWARF4 |
| bool "Generate dwarf4 debuginfo" |
| depends on $(cc-option,-gdwarf-4) |
| help |
| Generate dwarf4 debug info. This requires recent versions |
| of gcc and gdb. It makes the debug information larger. |
| But it significantly improves the success of resolving |
| variables in gdb on optimized code. |
| |
| config DEBUG_INFO_BTF |
| bool "Generate BTF typeinfo" |
| depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED |
| depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST |
| help |
| Generate deduplicated BTF type information from DWARF debug info. |
| Turning this on expects presence of pahole tool, which will convert |
| DWARF type info into equivalent deduplicated BTF type info. |
| |
| config GDB_SCRIPTS |
| bool "Provide GDB scripts for kernel debugging" |
| help |
| This creates the required links to GDB helper scripts in the |
| build directory. If you load vmlinux into gdb, the helper |
| scripts will be automatically imported by gdb as well, and |
| additional functions are available to analyze a Linux kernel |
| instance. See Documentation/dev-tools/gdb-kernel-debugging.rst |
| for further details. |
| |
| endif # DEBUG_INFO |
| |
| config ENABLE_MUST_CHECK |
| bool "Enable __must_check logic" |
| default y |
| help |
| Enable the __must_check logic in the kernel build. Disable this to |
| suppress the "warning: ignoring return value of 'foo', declared with |
| attribute warn_unused_result" messages. |
| |
| config FRAME_WARN |
| int "Warn for stack frames larger than" |
| range 0 8192 |
| default 2048 if GCC_PLUGIN_LATENT_ENTROPY |
| default 1280 if (!64BIT && PARISC) |
| default 1024 if (!64BIT && !PARISC) |
| default 2048 if 64BIT |
| help |
| Tell gcc 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 |
| help |
| Disable some compiler optimizations that tend to generate human unreadable |
| assembler output. This may make the kernel slightly slower, but it helps |
| to keep kernel developers who have to stare a lot at assembler listings |
| sane. |
| |
| config HEADERS_INSTALL |
| bool "Install uapi headers to usr/include" |
| depends on !UML |
| help |
| This option will install uapi headers (headers exported to user-space) |
| into the usr/include directory for use during the kernel build. |
| This is unneeded for building the kernel itself, but needed for some |
| user-space program samples. It is also needed by some features such |
| as uapi header sanity checks. |
| |
| config DEBUG_SECTION_MISMATCH |
| bool "Enable full Section mismatch analysis" |
| help |
| The section mismatch analysis checks if there are illegal |
| references from one section to another section. |
| During linktime or runtime, some sections are dropped; |
| any use of code/data previously in these sections would |
| most likely result in an oops. |
| In the code, functions and variables are annotated with |
| __init,, etc. (see the full list in include/linux/init.h), |
| which results in the code/data being placed in specific sections. |
| The section mismatch analysis is always performed after a full |
| kernel build, and enabling this option causes the following |
| additional step to occur: |
| - Add the option -fno-inline-functions-called-once to gcc commands. |
| When inlining a function annotated with __init in a non-init |
| function, we would lose the section information and thus |
| the analysis would not catch the illegal reference. |
| This option tells gcc to inline less (but it does result in |
| a larger kernel). |
| |
| config SECTION_MISMATCH_WARN_ONLY |
| bool "Make section mismatch errors non-fatal" |
| default y |
| help |
| If you say N here, the build process will fail if there are any |
| section mismatch, instead of just throwing warnings. |
| |
| If unsure, say Y. |
| |
| config DEBUG_FORCE_FUNCTION_ALIGN_32B |
| bool "Force all function address 32B aligned" if EXPERT |
| 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 STACK_VALIDATION |
| bool "Compile-time stack metadata validation" |
| depends on HAVE_STACK_VALIDATION |
| default n |
| help |
| Add compile-time checks to validate stack metadata, including frame |
| pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure |
| that runtime stack traces are more reliable. |
| |
| This is also a prerequisite for generation of ORC unwind data, which |
| is needed for CONFIG_UNWINDER_ORC. |
| |
| For more information, see |
| tools/objtool/Documentation/stack-validation.txt. |
| |
| config VMLINUX_VALIDATION |
| bool |
| depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT |
| default y |
| |
| config DEBUG_FORCE_WEAK_PER_CPU |
| bool "Force weak per-cpu definitions" |
| depends on DEBUG_KERNEL |
| help |
| s390 and alpha require percpu variables in modules to be |
| defined weak to work around addressing range issue which |
| puts the following two restrictions on percpu variable |
| definitions. |
| |
| 1. percpu symbols must be unique whether static or not |
| 2. percpu variables can't be defined inside a function |
| |
| To ensure that generic code follows the above rules, this |
| option forces all percpu variables to be defined as weak. |
| |
| endmenu # "Compiler options" |
| |
| menu "Generic Kernel Debugging Instruments" |
| |
| config MAGIC_SYSRQ |
| bool "Magic SysRq key" |
| depends on !UML |
| help |
| If you say Y here, you will have some control over the system even |
| if the system crashes for example during kernel debugging (e.g., you |
| will be able to flush the buffer cache to disk, reboot the system |
| immediately or dump some status information). This is accomplished |
| by pressing various keys while holding SysRq (Alt+PrintScreen). It |
| also works on a serial console (on PC hardware at least), if you |
| send a BREAK and then within 5 seconds a command keypress. The |
| keys are documented in <file:Documentation/admin-guide/sysrq.rst>. |
| Don't say Y unless you really know what this hack does. |
| |
| config MAGIC_SYSRQ_DEFAULT_ENABLE |
| hex "Enable magic SysRq key functions by default" |
| depends on MAGIC_SYSRQ |
| default 0x1 |
| help |
| Specifies which SysRq key functions are enabled by default. |
| This may be set to 1 or 0 to enable or disable them all, or |
| to a bitmask as described in Documentation/admin-guide/sysrq.rst. |
| |
| config MAGIC_SYSRQ_SERIAL |
| bool "Enable magic SysRq key over serial" |
| depends on MAGIC_SYSRQ |
| default y |
| help |
| Many embedded boards have a disconnected TTL level serial which can |
| generate some garbage that can lead to spurious false sysrq detects. |
| This option allows you to decide whether you want to enable the |
| magic SysRq key. |
| |
| config MAGIC_SYSRQ_SERIAL_SEQUENCE |
| string "Char sequence that enables magic SysRq over serial" |
| depends on MAGIC_SYSRQ_SERIAL |
| default "" |
| help |
| Specifies a sequence of characters that can follow BREAK to enable |
| SysRq on a serial console. |
| |
| If unsure, leave an empty string and the option will not be enabled. |
| |
| config DEBUG_FS |
| bool "Debug Filesystem" |
| help |
| debugfs is a virtual file system that kernel developers use to put |
| debugging files into. Enable this option to be able to read and |
| write to these files. |
| |
| For detailed documentation on the debugfs API, see |
| Documentation/filesystems/. |
| |
| If unsure, say N. |
| |
| choice |
| prompt "Debugfs default access" |
| depends on DEBUG_FS |
| default DEBUG_FS_ALLOW_ALL |
| help |
| This selects the default access restrictions for debugfs. |
| It can be overridden with kernel command line option |
| debugfs=[on,no-mount,off]. The restrictions apply for API access |
| and filesystem registration. |
| |
| config DEBUG_FS_ALLOW_ALL |
| bool "Access normal" |
| help |
| No restrictions apply. Both API and filesystem registration |
| is on. This is the normal default operation. |
| |
| config DEBUG_FS_DISALLOW_MOUNT |
| bool "Do not register debugfs as filesystem" |
| help |
| The API is open but filesystem is not loaded. Clients can still do |
| their work and read with debug tools that do not need |
| debugfs filesystem. |
| |
| config DEBUG_FS_ALLOW_NONE |
| bool "No access" |
| help |
| Access is off. Clients get -PERM when trying to create nodes in |
| debugfs tree and debugfs is not registered as a filesystem. |
| Client can then back-off or continue without debugfs access. |
| |
| endchoice |
| |
| source "lib/Kconfig.kgdb" |
| source "lib/Kconfig.ubsan" |
| source "lib/Kconfig.kcsan" |
| |
| endmenu |
| |
| 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 "Memory Debugging" |
| |
| source "mm/Kconfig.debug" |
| |
| config DEBUG_OBJECTS |
| bool "Debug object operations" |
| depends on DEBUG_KERNEL |
| help |
| If you say Y here, additional code will be inserted into the |
| kernel to track the life time of various objects and validate |
| the operations on those objects. |
| |
| config DEBUG_OBJECTS_SELFTEST |
| bool "Debug objects selftest" |
| depends on DEBUG_OBJECTS |
| help |
| This enables the selftest of the object debug code. |
| |
| config DEBUG_OBJECTS_FREE |
| bool "Debug objects in freed memory" |
| depends on DEBUG_OBJECTS |
| help |
| This enables checks whether a k/v free operation frees an area |
| which contains an object which has not been deactivated |
| properly. This can make kmalloc/kfree-intensive workloads |
| much slower. |
| |
| config DEBUG_OBJECTS_TIMERS |
| bool "Debug timer objects" |
| depends on DEBUG_OBJECTS |
| help |
| If you say Y here, additional code will be inserted into the |
| timer routines to track the life time of timer objects and |
| validate the timer operations. |
| |
| config DEBUG_OBJECTS_WORK |
| bool "Debug work objects" |
| depends on DEBUG_OBJECTS |
| help |
| If you say Y here, additional code will be inserted into the |
| work queue routines to track the life time of work objects and |
| validate the work operations. |
| |
| config DEBUG_OBJECTS_RCU_HEAD |
| bool "Debug RCU callbacks objects" |
| depends on DEBUG_OBJECTS |
| help |
| Enable this to turn on debugging of RCU list heads (call_rcu() usage). |
| |
| config DEBUG_OBJECTS_PERCPU_COUNTER |
| bool "Debug percpu counter objects" |
| depends on DEBUG_OBJECTS |
| help |
| If you say Y here, additional code will be inserted into the |
| percpu counter routines to track the life time of percpu counter |
| objects and validate the percpu counter operations. |
| |
| config DEBUG_OBJECTS_ENABLE_DEFAULT |
| int "debug_objects bootup default value (0-1)" |
| range 0 1 |
| default "1" |
| depends on DEBUG_OBJECTS |
| help |
| Debug objects boot parameter default value |
| |
| config DEBUG_SLAB |
| bool "Debug slab memory allocations" |
| depends on DEBUG_KERNEL && SLAB |
| help |
| Say Y here to have the kernel do limited verification on memory |
| allocation as well as poisoning memory on free to catch use of freed |
| memory. This can make kmalloc/kfree-intensive workloads much slower. |
| |
| config SLUB_DEBUG_ON |
| bool "SLUB debugging on by default" |
| depends on SLUB && SLUB_DEBUG |
| default n |
| help |
| Boot with debugging on by default. SLUB boots by default with |
| the runtime debug capabilities switched off. Enabling this is |
| equivalent to specifying the "slub_debug" parameter on boot. |
| There is no support for more fine grained debug control like |
| possible with slub_debug=xxx. SLUB debugging may be switched |
| off in a kernel built with CONFIG_SLUB_DEBUG_ON by specifying |
| "slub_debug=-". |
| |
| config SLUB_STATS |
| default n |
| bool "Enable SLUB performance statistics" |
| depends on SLUB && SYSFS |
| help |
| SLUB statistics are useful to debug SLUBs allocation behavior in |
| order find ways to optimize the allocator. This should never be |
| enabled for production use since keeping statistics slows down |
| the allocator by a few percentage points. The slabinfo command |
| supports the determination of the most active slabs to figure |
| out which slabs are relevant to a particular load. |
| Try running: slabinfo -DA |
| |
| config HAVE_DEBUG_KMEMLEAK |
| bool |
| |
| config DEBUG_KMEMLEAK |
| bool "Kernel memory leak detector" |
| depends on DEBUG_KERNEL && HAVE_DEBUG_KMEMLEAK |
| select DEBUG_FS |
| select STACKTRACE if STACKTRACE_SUPPORT |
| select KALLSYMS |
| select CRC32 |
| help |
| Say Y here if you want to enable the memory leak |
| detector. The memory allocation/freeing is traced in a way |
| similar to the Boehm's conservative garbage collector, the |
| difference being that the orphan objects are not freed but |
| only shown in /sys/kernel/debug/kmemleak. Enabling this |
| feature will introduce an overhead to memory |
| allocations. See Documentation/dev-tools/kmemleak.rst for more |
| details. |
| |
| Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances |
| of finding leaks due to the slab objects poisoning. |
| |
| In order to access the kmemleak file, debugfs needs to be |
| mounted (usually at /sys/kernel/debug). |
| |
| config DEBUG_KMEMLEAK_MEM_POOL_SIZE |
| int "Kmemleak memory pool size" |
| depends on DEBUG_KMEMLEAK |
| range 200 1000000 |
| default 16000 |
| help |
| Kmemleak must track all the memory allocations to avoid |
| reporting false positives. Since memory may be allocated or |
| freed before kmemleak is fully initialised, use a static pool |
| of metadata objects to track such callbacks. After kmemleak is |
| fully initialised, this memory pool acts as an emergency one |
| if slab allocations fail. |
| |
| config DEBUG_KMEMLEAK_TEST |
| tristate "Simple test for the kernel memory leak detector" |
| depends on DEBUG_KMEMLEAK && m |
| help |
| This option enables a module that explicitly leaks memory. |
| |
| If unsure, say N. |
| |
| config DEBUG_KMEMLEAK_DEFAULT_OFF |
| bool "Default kmemleak to off" |
| depends on DEBUG_KMEMLEAK |
| help |
| Say Y here to disable kmemleak by default. It can then be enabled |
| on the command line via kmemleak=on. |
| |
| config DEBUG_KMEMLEAK_AUTO_SCAN |
| bool "Enable kmemleak auto scan thread on boot up" |
| default y |
| depends on DEBUG_KMEMLEAK |
| help |
| Depending on the cpu, kmemleak scan may be cpu intensive and can |
| stall user tasks at times. This option enables/disables automatic |
| kmemleak scan at boot up. |
| |
| Say N here to disable kmemleak auto scan thread to stop automatic |
| scanning. Disabling this option disables automatic reporting of |
| memory leaks. |
| |
| If unsure, say Y. |
| |
| config DEBUG_STACK_USAGE |
| bool "Stack utilization instrumentation" |
| depends on DEBUG_KERNEL && !IA64 |
| 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. |
| |
| This option will slow down process creation somewhat. |
| |
| config SCHED_STACK_END_CHECK |
| bool "Detect stack corruption on calls to schedule()" |
| depends on DEBUG_KERNEL |
| default n |
| help |
| This option checks for a stack overrun on calls to schedule(). |
| If the stack end location is found to be over written always panic as |
| the content of the corrupted region can no longer be trusted. |
| This is to ensure no erroneous behaviour occurs which could result in |
| data corruption or a sporadic crash at a later stage once the region |
| is examined. The runtime overhead introduced is minimal. |
| |
| config ARCH_HAS_DEBUG_VM_PGTABLE |
| bool |
| help |
| An architecture should select this when it can successfully |
| build and run DEBUG_VM_PGTABLE. |
| |
| config DEBUG_VM |
| 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_VMACACHE |
| bool "Debug VMA caching" |
| depends on DEBUG_VM |
| help |
| Enable this to turn on VMA caching debug information. Doing so |
| can cause significant overhead, so only enable it in non-production |
| environments. |
| |
| 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_SPARSE && 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_HIGHMEM |
| bool "Highmem debugging" |
| depends on DEBUG_KERNEL && HIGHMEM |
| 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". |
| |
| source "lib/Kconfig.kasan" |
| |
| endmenu # "Memory Debugging" |
| |
| config DEBUG_SHIRQ |
| bool "Debug shared IRQ handlers" |
| depends on DEBUG_KERNEL |
| help |
| Enable this to generate a spurious interrupt just before a shared |
| interrupt handler is deregistered (generating one when registering |
| is currently disabled). Drivers need to handle this correctly. Some |
| don't and need to be caught. |
| |
| menu "Debug Oops, Lockups and Hangs" |
| |
| config PANIC_ON_OOPS |
| bool "Panic on Oops" |
| help |
| Say Y here to enable the kernel to panic when it oopses. This |
| has the same effect as setting oops=panic on the kernel command |
| line. |
| |
| This feature is useful to ensure that the kernel does not do |
| anything erroneous after an oops which could result in data |
| corruption or other issues. |
| |
| Say N if unsure. |
| |
| config PANIC_ON_OOPS_VALUE |
| int |
| range 0 1 |
| default 0 if !PANIC_ON_OOPS |
| default 1 if PANIC_ON_OOPS |
| |
| config PANIC_TIMEOUT |
| int "panic timeout" |
| default 0 |
| help |
| Set the timeout value (in seconds) until a reboot occurs when |
| the kernel panics. If n = 0, then we wait forever. A timeout |
| value n > 0 will wait n seconds before rebooting, while a timeout |
| value n < 0 will reboot immediately. |
| |
| 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 BOOTPARAM_SOFTLOCKUP_PANIC |
| bool "Panic (Reboot) On Soft Lockups" |
| depends on SOFTLOCKUP_DETECTOR |
| help |
| Say Y here to enable the kernel to panic on "soft lockups", |
| which are bugs that cause the kernel to loop in kernel |
| mode for more than 20 seconds (configurable using the watchdog_thresh |
| sysctl), without giving other tasks a chance to run. |
| |
| The panic can be used in combination with panic_timeout, |
| to cause the system to reboot automatically after a |
| lockup has been detected. This feature is useful for |
| high-availability systems that have uptime guarantees and |
| where a lockup must be resolved ASAP. |
| |
| Say N if unsure. |
| |
| config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE |
| int |
| depends on SOFTLOCKUP_DETECTOR |
| range 0 1 |
| default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC |
| default 1 if BOOTPARAM_SOFTLOCKUP_PANIC |
| |
| config HARDLOCKUP_DETECTOR_PERF |
| 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 |
| |
| # |
| # arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard |
| # lockup detector rather than the perf based detector. |
| # |
| config HARDLOCKUP_DETECTOR |
| bool "Detect Hard Lockups" |
| depends on DEBUG_KERNEL && !S390 |
| depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH |
| select LOCKUP_DETECTOR |
| select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF |
| select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH |
| 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. |
| |
| 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 BOOTPARAM_HARDLOCKUP_PANIC_VALUE |
| int |
| depends on HARDLOCKUP_DETECTOR |
| range 0 1 |
| default 0 if !BOOTPARAM_HARDLOCKUP_PANIC |
| default 1 if BOOTPARAM_HARDLOCKUP_PANIC |
| |
| config DETECT_HUNG_TASK |
| bool "Detect Hung Tasks" |
| depends on DEBUG_KERNEL |
| default SOFTLOCKUP_DETECTOR |
| help |
| Say Y here to enable the kernel to detect "hung tasks", |
| which are bugs that cause the task to be stuck in |
| uninterruptible "D" state indefinitely. |
| |
| When a hung task is detected, the kernel will print the |
| current stack trace (which you should report), but the |
| task will stay in uninterruptible state. If lockdep is |
| enabled then all held locks will also be reported. This |
| feature has negligible overhead. |
| |
| config DEFAULT_HUNG_TASK_TIMEOUT |
| int "Default timeout for hung task detection (in seconds)" |
| depends on DETECT_HUNG_TASK |
| default 120 |
| help |
| This option controls the default timeout (in seconds) used |
| to determine when a task has become non-responsive and should |
| be considered hung. |
| |
| It can be adjusted at runtime via the kernel.hung_task_timeout_secs |
| sysctl or by writing a value to |
| /proc/sys/kernel/hung_task_timeout_secs. |
| |
| A timeout of 0 disables the check. The default is two minutes. |
| Keeping the default should be fine in most cases. |
| |
| config BOOTPARAM_HUNG_TASK_PANIC |
| bool "Panic (Reboot) On Hung Tasks" |
| depends on DETECT_HUNG_TASK |
| help |
| Say Y here to enable the kernel to panic on "hung tasks", |
| which are bugs that cause the kernel to leave a task stuck |
| in uninterruptible "D" state. |
| |
| The panic can be used in combination with panic_timeout, |
| to cause the system to reboot automatically after a |
| hung task has been detected. This feature is useful for |
| high-availability systems that have uptime guarantees and |
| where a hung tasks must be resolved ASAP. |
| |
| Say N if unsure. |
| |
| config BOOTPARAM_HUNG_TASK_PANIC_VALUE |
| int |
| depends on DETECT_HUNG_TASK |
| range 0 1 |
| default 0 if !BOOTPARAM_HUNG_TASK_PANIC |
| default 1 if BOOTPARAM_HUNG_TASK_PANIC |
| |
| 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 TEST_LOCKUP |
| tristate "Test module to generate lockups" |
| depends on m |
| help |
| This builds the "test_lockup" module that helps to make sure |
| that watchdogs and lockup detectors are working properly. |
| |
| Depending on module parameters it could emulate soft or hard |
| lockup, "hung task", or locking arbitrary lock for a long time. |
| Also it could generate series of lockups with cooling-down periods. |
| |
| If unsure, say N. |
| |
| endmenu # "Debug lockups and hangs" |
| |
| menu "Scheduler Debugging" |
| |
| config SCHED_DEBUG |
| bool "Collect scheduler debugging info" |
| depends on DEBUG_KERNEL && PROC_FS |
| default y |
| help |
| If you say Y here, the /proc/sched_debug file will be provided |
| that can help debug the scheduler. The runtime overhead of this |
| option is minimal. |
| |
| config SCHED_INFO |
| bool |
| default n |
| |
| config SCHEDSTATS |
| bool "Collect scheduler statistics" |
| depends on DEBUG_KERNEL && PROC_FS |
| select SCHED_INFO |
| help |
| If you say Y here, additional code will be inserted into the |
| scheduler and related routines to collect statistics about |
| scheduler behavior and provide them in /proc/schedstat. These |
| stats may be useful for both tuning and debugging the scheduler |
| If you aren't debugging the scheduler or trying to tune a specific |
| application, you can say N to avoid the very slight overhead |
| this adds. |
| |
| endmenu |
| |
| config DEBUG_TIMEKEEPING |
| bool "Enable extra timekeeping sanity checking" |
| help |
| This option will enable additional timekeeping sanity checks |
| which may be helpful when diagnosing issues where timekeeping |
| problems are suspected. |
| |
| This may include checks in the timekeeping hotpaths, so this |
| option may have a (very small) performance impact to some |
| workloads. |
| |
| If unsure, say N. |
| |
| config DEBUG_PREEMPT |
| bool "Debug preemptible kernel" |
| depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT |
| default y |
| 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. |
| |
| 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 |
| select DEBUG_RT_MUTEXES if RT_MUTEXES |
| select DEBUG_RWSEMS |
| select DEBUG_WW_MUTEX_SLOWPATH |
| select DEBUG_LOCK_ALLOC |
| select PREEMPT_COUNT if !ARCH_NO_PREEMPT |
| select TRACE_IRQFLAGS |
| default n |
| help |
| This feature enables the kernel to prove that all locking |
| that occurs in the kernel runtime is mathematically |
| correct: that under no circumstance could an arbitrary (and |
| not yet triggered) combination of observed locking |
| sequences (on an arbitrary number of CPUs, running an |
| arbitrary number of tasks and interrupt contexts) cause a |
| deadlock. |
| |
| In short, this feature enables the kernel to report locking |
| related deadlocks before they actually occur. |
| |
| The proof does not depend on how hard and complex a |
| deadlock scenario would be to trigger: how many |
| participant CPUs, tasks and irq-contexts would be needed |
| for it to trigger. The proof also does not depend on |
| timing: if a race and a resulting deadlock is possible |
| theoretically (no matter how unlikely the race scenario |
| is), it will be proven so and will immediately be |
| reported by the kernel (once the event is observed that |
| makes the deadlock theoretically possible). |
| |
| If a deadlock is impossible (i.e. the locking rules, as |
| observed by the kernel, are mathematically correct), the |
| kernel reports nothing. |
| |
| NOTE: this feature can also be enabled for rwlocks, mutexes |
| and rwsems - in which case all dependencies between these |
| different locking variants are observed and mapped too, and |
| the proof of observed correctness is also maintained for an |
| arbitrary combination of these separate locking variants. |
| |
| For more details, see Documentation/locking/lockdep-design.rst. |
| |
| config PROVE_RAW_LOCK_NESTING |
| bool "Enable raw_spinlock - spinlock nesting checks" |
| depends on PROVE_LOCKING |
| default n |
| help |
| Enable the raw_spinlock vs. spinlock nesting checks which ensure |
| that the lock nesting rules for PREEMPT_RT enabled kernels are |
| not violated. |
| |
| NOTE: There are known nesting problems. So if you enable this |
| option expect lockdep splats until these problems have been fully |
| addressed which is work in progress. This config switch allows to |
| identify and analyze these problems. It will be removed and the |
| check permanentely enabled once the main issues have been fixed. |
| |
| If unsure, select N. |
| |
| config LOCK_STAT |
| bool "Lock usage statistics" |
| depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT |
| select LOCKDEP |
| select DEBUG_SPINLOCK |
| select DEBUG_MUTEXES |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86 |
| select KALLSYMS |
| select KALLSYMS_ALL |
| |
| config LOCKDEP_SMALL |
| bool |
| |
| config DEBUG_LOCKDEP |
| bool "Lock dependency engine debugging" |
| depends on DEBUG_KERNEL && LOCKDEP |
| 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 wont be detected of course.) |
| The following locking APIs are covered: spinlocks, rwlocks, |
| mutexes and rwsems. |
| |
| config LOCK_TORTURE_TEST |
| tristate "torture tests for locking" |
| depends on DEBUG_KERNEL |
| select TORTURE_TEST |
| help |
| This option provides a kernel module that runs torture tests |
| on kernel locking primitives. The kernel module may be built |
| after the fact on the running kernel to be tested, if desired. |
| |
| Say Y here if you want kernel locking-primitive torture tests |
| to be built into the kernel. |
| Say M if you want these torture tests to build as a module. |
| Say N if you are unsure. |
| |
| config WW_MUTEX_SELFTEST |
| tristate "Wait/wound mutex selftests" |
| help |
| This option provides a kernel module that runs tests on the |
| on the struct ww_mutex locking API. |
| |
| It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction |
| with this test harness. |
| |
| Say M if you want these self tests to build as a module. |
| Say N if you are unsure. |
| |
| config SCF_TORTURE_TEST |
| tristate "torture tests for smp_call_function*()" |
| depends on DEBUG_KERNEL |
| select TORTURE_TEST |
| help |
| This option provides a kernel module that runs torture tests |
| on the smp_call_function() family of primitives. The kernel |
| module may be built after the fact on the running kernel to |
| be tested, if desired. |
| |
| config CSD_LOCK_WAIT_DEBUG |
| bool "Debugging for csd_lock_wait(), called from smp_call_function*()" |
| depends on DEBUG_KERNEL |
| depends on 64BIT |
| default n |
| help |
| This option enables debug prints when CPUs are slow to respond |
| to the smp_call_function*() IPI wrappers. These debug prints |
| include the IPI handler function currently executing (if any) |
| and relevant stack traces. |
| |
| 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 STACKTRACE |
| bool "Stack backtrace support" |
| depends on STACKTRACE_SUPPORT |
| help |
| This option causes the kernel to create a /proc/pid/stack for |
| every process, showing its current stack trace. |
| It is also used by various kernel debugging features that require |
| stack trace generation. |
| |
| config WARN_ALL_UNSEEDED_RANDOM |
| bool "Warn for all uses of unseeded randomness" |
| default n |
| help |
| Some parts of the kernel contain bugs relating to their use of |
| cryptographically secure random numbers before it's actually possible |
| to generate those numbers securely. This setting ensures that these |
| flaws don't go unnoticed, by enabling a message, should this ever |
| occur. This will allow people with obscure setups to know when things |
| are going wrong, so that they might contact developers about fixing |
| it. |
| |
| Unfortunately, on some models of some architectures getting |
| a fully seeded CRNG is extremely difficult, and so this can |
| result in dmesg getting spammed for a surprisingly long |
| time. This is really bad from a security perspective, and |
| so architecture maintainers really need to do what they can |
| to get the CRNG seeded sooner after the system is booted. |
| However, since users cannot do anything actionable to |
| address this, by default the kernel will issue only a single |
| warning for the first use of unseeded randomness. |
| |
| Say Y here if you want to receive warnings for all uses of |
| unseeded randomness. This will be of use primarily for |
| those developers interested in improving the security of |
| Linux kernels running on their architecture (or |
| subarchitecture). |
| |
| config DEBUG_KOBJECT |
| bool "kobject debugging" |
| depends on DEBUG_KERNEL |
| help |
| If you say Y here, some extra kobject debugging messages will be sent |
| to the syslog. |
| |
| config DEBUG_KOBJECT_RELEASE |
| bool "kobject release debugging" |
| depends on DEBUG_OBJECTS_TIMERS |
| help |
| kobjects are reference counted objects. This means that their |
| last reference count put is not predictable, and the kobject can |
| live on past the point at which a driver decides to drop it's |
| 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 || BUG_ON_DATA_CORRUPTION |
| help |
| Enable this to turn on extended checks in the linked-list |
| walking routines. |
| |
| 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 BUG_ON_DATA_CORRUPTION |
| bool "Trigger a BUG when data corruption is detected" |
| select DEBUG_LIST |
| help |
| Select this option if the kernel should BUG when it encounters |
| data corruption in kernel memory structures when they get checked |
| for validity. |
| |
| If unsure, say N. |
| |
| endmenu |
| |
| config DEBUG_CREDENTIALS |
| bool "Debug credential management" |
| depends on DEBUG_KERNEL |
| help |
| Enable this to turn on some debug checking for credential |
| management. The additional code keeps track of the number of |
| pointers from task_structs to any given cred struct, and checks to |
| see that this number never exceeds the usage count of the cred |
| struct. |
| |
| Furthermore, if SELinux is enabled, this also checks that the |
| security pointer in the cred struct is never seen to be invalid. |
| |
| If unsure, say N. |
| |
| 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 DEBUG_BLOCK_EXT_DEVT |
| bool "Force extended block device numbers and spread them" |
| depends on DEBUG_KERNEL |
| depends on BLOCK |
| default n |
| help |
| BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON |
| SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT |
| YOU ARE DOING. Distros, please enable this and fix whatever |
| is broken. |
| |
| Conventionally, block device numbers are allocated from |
| predetermined contiguous area. However, extended block area |
| may introduce non-contiguous block device numbers. This |
| option forces most block device numbers to be allocated from |
| the extended space and spreads them to discover kernel or |
| userland code paths which assume predetermined contiguous |
| device number allocation. |
| |
| Note that turning on this debug option shuffles all the |
| device numbers for all IDE and SCSI devices including libata |
| ones, so root partition specified using device number |
| directly (via rdev or root=MAJ:MIN) won't work anymore. |
| Textual device names (root=/dev/sdXn) will continue to work. |
| |
| Say N if you are unsure. |
| |
| 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 |
| select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 |
| select KALLSYMS |
| select KALLSYMS_ALL |
| select STACKTRACE |
| select SCHEDSTATS |
| select SCHED_DEBUG |
| help |
| Enable this option if you want to use the LatencyTOP tool |
| to find out which userspace is blocking on what kernel operations. |
| |
| 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 |
| default y if PPC || X86 || ARM64 |
| help |
| If this option is disabled, you allow userspace (root) access to all |
| of memory, including kernel and userspace memory. Accidental |
| access to this is obviously disastrous, but specific access can |
| be used by people debugging the kernel. Note that with PAT support |
| enabled, even in this case there are restrictions on /dev/mem |
| use due to the cache aliasing requirements. |
| |
| If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem |
| file only allows userspace access to PCI space and the BIOS code and |
| data regions. This is sufficient for dosemu and X and all common |
| users of /dev/mem. |
| |
| If in doubt, say Y. |
| |
| config IO_STRICT_DEVMEM |
| bool "Filter I/O access to /dev/mem" |
| depends on STRICT_DEVMEM |
| help |
| If this option is disabled, you allow userspace (root) access to all |
| io-memory regardless of whether a driver is actively using that |
| range. Accidental access to this is obviously disastrous, but |
| specific access can be used by people debugging kernel drivers. |
| |
| If this option is switched on, the /dev/mem file only allows |
| userspace access to *idle* io-memory ranges (see /proc/iomem) This |
| may break traditional users of /dev/mem (dosemu, legacy X, etc...) |
| if the driver using a given range cannot be disabled. |
| |
| If in doubt, say Y. |
| |
| menu "$(SRCARCH) Debugging" |
| |
| source "arch/$(SRCARCH)/Kconfig.debug" |
| |
| endmenu |
| |
| menu "Kernel Testing and Coverage" |
| |
| source "lib/kunit/Kconfig" |
| |
| config NOTIFIER_ERROR_INJECTION |
| tristate "Notifier error injection" |
| depends on DEBUG_KERNEL |
| select DEBUG_FS |
| help |
| This option provides the ability to inject artificial errors to |
| specified notifier chain callbacks. It is useful to test the error |
| handling of notifier call chain failures. |
| |
| Say N if unsure. |
| |
| config PM_NOTIFIER_ERROR_INJECT |
| tristate "PM notifier error injection module" |
| depends on PM && NOTIFIER_ERROR_INJECTION |
| default m if PM_DEBUG |
| help |
| This option provides the ability to inject artificial errors to |
| PM notifier chain callbacks. It is controlled through debugfs |
| interface /sys/kernel/debug/notifier-error-inject/pm |
| |
| If the notifier call chain should be failed with some events |
| notified, write the error code to "actions/<notifier event>/error". |
| |
| Example: Inject PM suspend error (-12 = -ENOMEM) |
| |
| # cd /sys/kernel/debug/notifier-error-inject/pm/ |
| # echo -12 > actions/PM_SUSPEND_PREPARE/error |
| # echo mem > /sys/power/state |
| bash: echo: write error: Cannot allocate memory |
| |
| To compile this code as a module, choose M here: the module will |
| be called pm-notifier-error-inject. |
| |
| If unsure, say N. |
| |
| config OF_RECONFIG_NOTIFIER_ERROR_INJECT |
| tristate "OF reconfig notifier error injection module" |
| depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION |
| help |
| This option provides the ability to inject artificial errors to |
| OF reconfig notifier chain callbacks. It is controlled |
| through debugfs interface under |
| /sys/kernel/debug/notifier-error-inject/OF-reconfig/ |
| |
| If the notifier call chain should be failed with some events |
| notified, write the error code to "actions/<notifier event>/error". |
| |
| To compile this code as a module, choose M here: the module will |
| be called of-reconfig-notifier-error-inject. |
| |
| If unsure, say N. |
| |
| config NETDEV_NOTIFIER_ERROR_INJECT |
| tristate "Netdev notifier error injection module" |
| depends on NET && NOTIFIER_ERROR_INJECTION |
| help |
| This option provides the ability to inject artificial errors to |
| netdevice notifier chain callbacks. It is controlled through debugfs |
| interface /sys/kernel/debug/notifier-error-inject/netdev |
| |
| If the notifier call chain should be failed with some events |
| notified, write the error code to "actions/<notifier event>/error". |
| |
| Example: Inject netdevice mtu change error (-22 = -EINVAL) |
| |
| # cd /sys/kernel/debug/notifier-error-inject/netdev |
| # echo -22 > actions/NETDEV_CHANGEMTU/error |
| # ip link set eth0 mtu 1024 |
| RTNETLINK answers: Invalid argument |
| |
| To compile this code as a module, choose M here: the module will |
| be called netdev-notifier-error-inject. |
| |
| If unsure, say N. |
| |
| config FUNCTION_ERROR_INJECTION |
| def_bool y |
| depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES |
| |
| 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 |
| depends on SLAB || SLUB |
| 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 wont 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 FAULT_INJECTION_STACKTRACE_FILTER |
| bool "stacktrace filter for fault-injection capabilities" |
| depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT |
| depends on !X86_64 |
| select STACKTRACE |
| select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 |
| help |
| Provide stacktrace filter for fault-injection capabilities |
| |
| config ARCH_HAS_KCOV |
| bool |
| help |
| An architecture should select this when it can successfully |
| build and run with CONFIG_KCOV. This typically requires |
| disabling instrumentation for some early boot code. |
| |
| config CC_HAS_SANCOV_TRACE_PC |
| def_bool $(cc-option,-fsanitize-coverage=trace-pc) |
| |
| |
| config KCOV |
| bool "Code coverage for fuzzing" |
| depends on ARCH_HAS_KCOV |
| depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS |
| select DEBUG_FS |
| select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC |
| help |
| KCOV exposes kernel code coverage information in a form suitable |
| for coverage-guided fuzzing (randomized testing). |
| |
| If RANDOMIZE_BASE is enabled, PC values will not be stable across |
| different machines and across reboots. If you need stable PC values, |
| disable RANDOMIZE_BASE. |
| |
| For more details, see Documentation/dev-tools/kcov.rst. |
| |
| config KCOV_ENABLE_COMPARISONS |
| bool "Enable comparison operands collection by KCOV" |
| depends on KCOV |
| depends on $(cc-option,-fsanitize-coverage=trace-cmp) |
| help |
| KCOV also exposes operands of every comparison in the instrumented |
| code along with operand sizes and PCs of the comparison instructions. |
| These operands can be used by fuzzing engines to improve the quality |
| of fuzzing coverage. |
| |
| config KCOV_INSTRUMENT_ALL |
| bool "Instrument all code by default" |
| depends on KCOV |
| default y |
| help |
| If you are doing generic system call fuzzing (like e.g. syzkaller), |
| then you will want to instrument the whole kernel and you should |
| say y here. If you are doing more targeted fuzzing (like e.g. |
| filesystem fuzzing with AFL) then you will want to enable coverage |
| for more specific subsets of files, and should say n here. |
| |
| config KCOV_IRQ_AREA_SIZE |
| hex "Size of interrupt coverage collection area in words" |
| depends on KCOV |
| default 0x40000 |
| help |
| KCOV uses preallocated per-cpu areas to collect coverage from |
| soft interrupts. This specifies the size of those areas in the |
| number of unsigned long words. |
| |
| menuconfig RUNTIME_TESTING_MENU |
| bool "Runtime Testing" |
| def_bool y |
| |
| if RUNTIME_TESTING_MENU |
| |
| 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 TEST_LIST_SORT |
| tristate "Linked list sorting test" |
| depends on DEBUG_KERNEL || m |
| help |
| Enable this to turn on 'list_sort()' function test. This test is |
| executed only once during system boot (so affects only boot time), |
| or at module load time. |
| |
| If unsure, say N. |
| |
| config TEST_MIN_HEAP |
| tristate "Min heap test" |
| depends on DEBUG_KERNEL || m |
| help |
| Enable this to turn on min heap function tests. This test is |
| executed only once during system boot (so affects only boot time), |
| or at module load time. |
| |
| If unsure, say N. |
| |
| config TEST_SORT |
| tristate "Array-based sort test" |
| depends on DEBUG_KERNEL || m |
| help |
| This option enables the self-test function of 'sort()' at boot, |
| or at module load time. |
| |
| If unsure, say N. |
| |
| config KPROBES_SANITY_TEST |
| bool "Kprobes sanity tests" |
| depends on DEBUG_KERNEL |
| depends on KPROBES |
| 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 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 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 TEST_STRING_HELPERS |
| tristate "Test functions located in the string_helpers module at runtime" |
| |
| config TEST_STRSCPY |
| tristate "Test strscpy*() family of functions at runtime" |
| |
| config TEST_KSTRTOX |
| tristate "Test kstrto*() family of functions at runtime" |
| |
| config TEST_PRINTF |
| tristate "Test printf() family of functions at runtime" |
| |
| config TEST_BITMAP |
| tristate "Test bitmap_*() family of functions at runtime" |
| help |
| Enable this option to test the bitmap functions at boot. |
| |
| If unsure, say N. |
| |
| config TEST_UUID |
| tristate "Test functions located in the uuid module at runtime" |
| |
| config TEST_XARRAY |
| tristate "Test the XArray code at runtime" |
| |
| config TEST_OVERFLOW |
| tristate "Test check_*_overflow() functions at runtime" |
| |
| 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_HASH |
| tristate "Perform selftest on hash functions" |
| help |
| Enable this option to test the kernel's integer (<linux/hash.h>), |
| string (<linux/stringhash.h>), and 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 TEST_IDA |
| tristate "Perform selftest on IDA functions" |
| |
| config TEST_PARMAN |
| tristate "Perform selftest on priority array manager" |
| depends on PARMAN |
| help |
| Enable this option to test priority array manager on boot |
| (or module load). |
| |
| If unsure, say N. |
| |
| config TEST_IRQ_TIMINGS |
| bool "IRQ timings selftest" |
| depends on IRQ_TIMINGS |
| help |
| Enable this option to test the irq timings code on boot. |
| |
| If unsure, say N. |
| |
| config TEST_LKM |
| tristate "Test module loading with 'hello world' module" |
| depends on m |
| help |
| This builds the "test_module" module that emits "Hello, world" |
| on printk when loaded. It is designed to be used for basic |
| evaluation of the module loading subsystem (for example when |
| validating module verification). It lacks any extra dependencies, |
| and will not normally be loaded by the system unless explicitly |
| requested by name. |
| |
| If unsure, say N. |
| |
| config TEST_BITOPS |
| tristate "Test module for compilation of bitops operations" |
| depends on m |
| help |
| This builds the "test_bitops" module that is much like the |
| TEST_LKM module except that it does a basic exercise of the |
| set/clear_bit macros and get_count_order/long to make sure there are |
| no compiler warnings from C=1 sparse checker or -Wextra |
| compilations. It has no dependencies and doesn't run or load unless |
| explicitly requested by name. for example: modprobe test_bitops. |
| |
| If unsure, say N. |
| |
| config TEST_VMALLOC |
| tristate "Test module for stress/performance analysis of vmalloc allocator" |
| default n |
| depends on MMU |
| depends on m |
| help |
| This builds the "test_vmalloc" module that should be used for |
| stress and performance analysis. So, any new change for vmalloc |
| subsystem can be evaluated from performance and stability point |
| of view. |
| |
| If unsure, say N. |
| |
| config TEST_USER_COPY |
| tristate "Test user/kernel boundary protections" |
| depends on m |
| help |
| This builds the "test_user_copy" module that runs sanity checks |
| on the copy_to/from_user infrastructure, making sure basic |
| user/kernel boundary testing is working. If it fails to load, |
| a regression has been detected in the user/kernel memory boundary |
| protections. |
| |
| If unsure, say N. |
| |
| config TEST_BPF |
| tristate "Test BPF filter functionality" |
| depends on m && NET |
| help |
| This builds the "test_bpf" module that runs various test vectors |
| against the BPF interpreter or BPF JIT compiler depending on the |
| current setting. This is in particular useful for BPF JIT compiler |
| development, but also to run regression tests against changes in |
| the interpreter code. It also enables test stubs for eBPF maps and |
| verifier used by user space verifier testsuite. |
| |
| If unsure, say N. |
| |
| config TEST_BLACKHOLE_DEV |
| tristate "Test blackhole netdev functionality" |
| depends on m && NET |
| help |
| This builds the "test_blackhole_dev" module that validates the |
| data path through this blackhole netdev. |
| |
| If unsure, say N. |
| |
| config FIND_BIT_BENCHMARK |
| tristate "Test find_bit functions" |
| help |
| This builds the "test_find_bit" module that measure find_*_bit() |
| functions performance. |
| |
| If unsure, say N. |
| |
| config TEST_FIRMWARE |
| tristate "Test firmware loading via userspace interface" |
| depends on FW_LOADER |
| help |
| This builds the "test_firmware" module that creates a userspace |
| interface for testing firmware loading. This can be used to |
| control the triggering of firmware loading without needing an |
| actual firmware-using device. The contents can be rechecked by |
| userspace. |
| |
| If unsure, say N. |
| |
| config TEST_SYSCTL |
| tristate "sysctl test driver" |
| depends on PROC_SYSCTL |
| help |
| This builds the "test_sysctl" module. This driver enables to test the |
| proc sysctl interfaces available to drivers safely without affecting |
| production knobs which might alter system functionality. |
| |
| If unsure, say N. |
| |
| config BITFIELD_KUNIT |
| tristate "KUnit test bitfield functions at runtime" |
| depends on KUNIT |
| 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 SYSCTL_KUNIT_TEST |
| tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS |
| depends on KUNIT |
| default KUNIT_ALL_TESTS |
| help |
| This builds the proc sysctl unit test, which runs on boot. |
| Tests the API contract and implementation correctness of sysctl. |
| For more information on KUnit and unit tests in general please refer |
| to the KUnit documentation in Documentation/dev-tools/kunit/. |
| |
| If unsure, say N. |
| |
| config LIST_KUNIT_TEST |
| tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS |
| depends on KUNIT |
| default KUNIT_ALL_TESTS |
| help |
| This builds the linked list KUnit test suite. |
| It tests that the API and basic functionality of the list_head type |
| and associated macros. |
| |
| KUnit tests run during boot and output the results to the debug log |
| in TAP format (https://testanything.org/). Only useful for kernel devs |
| running the KUnit test harness, and not intended for inclusion into a |
| production build. |
| |
| For more information on KUnit and unit tests in general please refer |
| to the KUnit documentation in Documentation/dev-tools/kunit/. |
| |
| If unsure, say N. |
| |
| config 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 BITS_TEST |
| tristate "KUnit test for bits.h" |
| depends on KUNIT |
| 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 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_KMOD |
| tristate "kmod stress tester" |
| depends on m |
| depends on NETDEVICES && NET_CORE && INET # for TUN |
| depends on BLOCK |
| select TEST_LKM |
| select XFS_FS |
| select TUN |
| select BTRFS_FS |
| help |
| Test the kernel's module loading mechanism: kmod. kmod implements |
| support to load modules using the Linux kernel's usermode helper. |
| This test provides a series of tests against kmod. |
| |
| Although technically you can either build test_kmod as a module or |
| into the kernel we disallow building it into the kernel since |
| it stress tests request_module() and this will very likely cause |
| some issues by taking over precious threads available from other |
| module load requests, ultimately this could be fatal. |
| |
| To run tests run: |
| |
| tools/testing/selftests/kmod/kmod.sh --help |
| |
| If unsure, say N. |
| |
| config TEST_DEBUG_VIRTUAL |
| tristate "Test CONFIG_DEBUG_VIRTUAL feature" |
| depends on DEBUG_VIRTUAL |
| help |
| Test the kernel's ability to detect incorrect calls to |
| virt_to_phys() done against the non-linear part of the |
| kernel's virtual address map. |
| |
| If unsure, say N. |
| |
| config TEST_MEMCAT_P |
| tristate "Test memcat_p() helper function" |
| help |
| Test the memcat_p() helper for correctly merging two |
| pointer arrays together. |
| |
| If unsure, say N. |
| |
| config TEST_LIVEPATCH |
| tristate "Test livepatching" |
| default n |
| depends on DYNAMIC_DEBUG |
| depends on LIVEPATCH |
| depends on m |
| help |
| Test kernel livepatching features for correctness. The tests will |
| load test modules that will be livepatched in various scenarios. |
| |
| To run all the livepatching tests: |
| |
| make -C tools/testing/selftests TARGETS=livepatch run_tests |
| |
| Alternatively, individual tests may be invoked: |
| |
| tools/testing/selftests/livepatch/test-callbacks.sh |
| tools/testing/selftests/livepatch/test-livepatch.sh |
| tools/testing/selftests/livepatch/test-shadow-vars.sh |
| |
| 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_STACKINIT |
| tristate "Test level of stack variable initialization" |
| help |
| Test if the kernel is zero-initializing stack variables and |
| padding. Coverage is controlled by compiler flags, |
| CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF, |
| or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL. |
| |
| If unsure, say N. |
| |
| 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 X86 && !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. |
| |
| endif # RUNTIME_TESTING_MENU |
| |
| config MEMTEST |
| bool "Memtest" |
| help |
| This option adds a kernel parameter 'memtest', which allows memtest |
| to be set. |
| 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" |
| |
| source "Documentation/Kconfig" |
| |
| endmenu # Kernel hacking |
