| # 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 | |
| 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. Thus, the debugfs | |
| 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. | |
| 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. | |
| config DEBUG_INFO_REDUCED | |
| bool "Reduce debugging information" | |
| depends on DEBUG_INFO | |
| 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_SPLIT | |
| bool "Produce split debuginfo in .dwo files" | |
| depends on DEBUG_INFO | |
| 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 DEBUG_INFO | |
| 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 | |
| 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" | |
| depends on DEBUG_INFO | |
| 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. | |
| 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 (needs gcc 4.4)" | |
| 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. | |
| Requires gcc 4.4 | |
| 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 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. | |
| 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 OPTIMIZE_INLINING | |
| def_bool y | |
| help | |
| This option determines if the kernel forces gcc to inline the functions | |
| developers have marked 'inline'. Doing so takes away freedom from gcc to | |
| do what it thinks is best, which is desirable for the gcc 3.x series of | |
| compilers. The gcc 4.x series have a rewritten inlining algorithm and | |
| enabling this option will generate a smaller kernel there. Hopefully | |
| this algorithm is so good that allowing gcc 4.x and above to make the | |
| decision will become the default in the future. Until then this option | |
| is there to test gcc for this. | |
| 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. | |
| # | |
| # 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 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" | |
| 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 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 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 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 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 DEBUG_SHIRQ | |
| bool "Debug shared IRQ handlers" | |
| depends on DEBUG_KERNEL | |
| help | |
| Enable this to generate a spurious interrupt as soon as a shared | |
| interrupt handler is registered, and just before one is deregistered. | |
| Drivers ought to be able to handle interrupts coming in at those | |
| points; some don't and need to be caught. | |
| menu "Debug Lockups and Hangs" | |
| 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. | |
| endmenu # "Debug 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 | |
| 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 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. | |
| 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 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 && PREEMPT && 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 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 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. | |
| endmenu # lock debugging | |
| config TRACE_IRQFLAGS | |
| bool | |
| help | |
| Enables hooks to interrupt enabling and disabling for | |
| either tracing or lock debugging. | |
| 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 | |
| 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_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 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 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 capabilitiy for alloc_pages()" | |
| depends on FAULT_INJECTION | |
| help | |
| Provide fault-injection capability for alloc_pages(). | |
| 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 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/debugging-via-ohci1394.txt for more information. | |
| 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_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_BITFIELD | |
| tristate "Test bitfield functions at runtime" | |
| help | |
| Enable this option to test the bitfield 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_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 SYSCTL_KUNIT_TEST | |
| bool "KUnit test for sysctl" | |
| depends on KUNIT | |
| 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 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. | |
| 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 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. | |
| source "samples/Kconfig" | |
| source "lib/Kconfig.kgdb" | |
| source "lib/Kconfig.ubsan" | |
| 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. | |
| source "arch/$(SRCARCH)/Kconfig.debug" | |
| endmenu # Kernel hacking |