linux-6.15/lib/Kconfig.debug

1 # SPDX-License-Identifier: GPL-2.0-only
18 	  The behavior is also controlled by the kernel command line
19 	  parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
50 	int "Default console loglevel (1-15)"
60 	  Note: This does not affect the log level of un-prefixed printk()
61 	  usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
65 	int "quiet console loglevel (1-15)"
76 	int "Default message log level (1-7)"
82 	  This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
118 	  enabled/disabled based on various levels of scope - per source file,
130 	  Dynamic debugging is controlled via the 'dynamic_debug/control' file,
158 		nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
162 		nullarbor:~ # echo -n 'file svcsock.c +p' >
166 		nullarbor:~ # echo -n 'module nfsd +p' >
170 		nullarbor:~ # echo -n 'func svc_process +p' >
174 		nullarbor:~ # echo -n 'func svc_process -p' >
177 	  See Documentation/admin-guide/dynamic-debug-howto.rst for additional
207 	  debugging but costs about 70-100K of memory.
225 menu "Compile-time checks and compiler options"
235 # older binutils ports do not support when utilizing RISC-V style linker
238 	def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
246 	  This adds debug symbols to the kernel and modules (gcc -g), and
290 	  5.0+ accepts the -gdwarf-5 flag but only had partial support for some
294 	  15-18% savings in resulting image and debug info section sizes as
332 	depends on $(cc-option,-gz=zlib)
333 	depends on $(ld-option,--compress-debug-sections=zlib)
338 	  Users of dpkg-deb via debian/rules may find an increase in
347 	depends on $(cc-option,-gz=zstd)
348 	depends on $(ld-option,--compress-debug-sections=zstd)
359 	depends on $(cc-option,-gsplit-dwarf)
360 	# RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
362 	# https://github.com/llvm/llvm-project/issues/56642
406 	  Support for the --lang_exclude flag which makes pahole exclude
420 	bool "Allow loading modules with non-matching BTF type info"
436 	  instance. See Documentation/process/debugging/gdb-kernel-debugging.rst
457 	bool "Strip assembler-generated symbols during link"
460 	  Strip internal assembler-generated symbols during a link (symbols
477 	  This option will install uapi headers (headers exported to user-space)
480 	  user-space program samples. It is also needed by some features such
498 	  - Add the option -fno-inline-functions-called-once to gcc commands.
499 	    When inlining a function annotated with __init in a non-init
506 	bool "Make section mismatch errors non-fatal"
559 	bool "Compile-time stack metadata validation"
564 	  Validate frame pointer rules at compile-time.  This helps ensure that
580 	  Selecting this option will pass "-Map=vmlinux.map" to ld
602 	bool "Force weak per-cpu definitions"
631 	  keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
641 	  to a bitmask as described in Documentation/admin-guide/sysrq.rst.
682 	  debugfs=[on,no-mount,off]. The restrictions apply for API access
701 	  Access is off. Clients get -PERM when trying to create nodes in
703 	  Client can then back-off or continue without debugfs access.
743 	  properly. This can make kmalloc/kfree-intensive workloads
777 	int "debug_objects bootup default value (0-1)"
797 	  task has ever had available in the sysrq-T and sysrq-P debug output.
837 	  Enable this to turn on extended checks in the virtual-memory system
862 	bool "Debug VM red-black trees"
865 	  Enable VM red-black tree debugging information and extra validations.
870 	bool "Debug page-flags operations"
920 	  on the mminit_loglevel= command-line option.
929 	  memory hotplug notifier chain callbacks.  It is controlled through
930 	  debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
935 	  Example: Inject memory hotplug offline error (-12 == -ENOMEM)
937 	  # cd /sys/kernel/debug/notifier-error-inject/memory
938 	  # echo -12 > actions/MEM_GOING_OFFLINE/error
943 	  be called memory-notifier-error-inject.
975 	  mechanism for non-highmem pages and on non-highmem systems.
999 	  These kinds of bugs usually occur when call-chains in the
1129 	  high-availability systems that have uptime guarantees and
1168 # Note that arch-specific variants are always preferred.
1183 	  an arch-specific hardlockup detector or if resources needed
1206 	  The arch-specific implementation of the hardlockup detector will
1256 	  to determine when a task has become non-responsive and should
1277 	  high-availability systems that have uptime guarantees and
1305 	bool "Report per-cpu work items which hog CPU for too long"
1308 	  Say Y here to enable reporting of concurrency-managed per-cpu work
1312 	  them from stalling other per-cpu work items. Occassional
1326 	  Also it could generate series of lockups with cooling-down periods.
1359 	  if kernel code uses it in a preemption-unsafe way. Also, the kernel
1400 	 participant CPUs, tasks and irq-contexts would be needed
1413 	 and rwsems - in which case all dependencies between these
1418 	 For more details, see Documentation/locking/lockdep-design.rst.
1421 	bool "Enable raw_spinlock - spinlock nesting checks" if !ARCH_SUPPORTS_RT
1459 	bool "Spinlock and rw-lock debugging: basic checks"
1484 	 injecting additional -EDEADLK wound/backoff cases. Together with
1510 	 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1563 … Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1586 	bool "Locking API boot-time self-tests"
1589 	  Say Y here if you want the kernel to run a short self-test during
1590 	  bootup. The self-test checks whether common types of locking bugs
1605 	  Say Y here if you want kernel locking-primitive torture tests
1757 	  Enable this to turn on extended checks in the linked-list walking
1770 	  Enable this to turn on extended checks in the priority-ordered
1771 	  linked-list (plist) walking routines.  This checks the entire
1780 	  Enable this to turn on checks on scatter-gather tables. This can
1818 	bool "Force round-robin CPU selection for unbound work items"
1827 	  round-robin CPU selection to flush out usages which depend on the
1877 	  this feature to remotely access the memory of the crashed machine
1881 	  With remote DMA, you can monitor the printk buffer remotely using
1896 	  in charge of the OHCI-1394 controllers should be used instead.
1898 	  See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1930 	  io-memory regardless of whether a driver is actively using that
1935 	  userspace access to *idle* io-memory ranges (see /proc/iomem) This
1968 	  PM notifier chain callbacks.  It is controlled through debugfs
1969 	  interface /sys/kernel/debug/notifier-error-inject/pm
1974 	  Example: Inject PM suspend error (-12 = -ENOMEM)
1976 	  # cd /sys/kernel/debug/notifier-error-inject/pm/
1977 	  # echo -12 > actions/PM_SUSPEND_PREPARE/error
1982 	  be called pm-notifier-error-inject.
1991 	  OF reconfig notifier chain callbacks.  It is controlled
1993 	  /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1999 	  be called of-reconfig-notifier-error-inject.
2008 	  netdevice notifier chain callbacks.  It is controlled through debugfs
2009 	  interface /sys/kernel/debug/notifier-error-inject/netdev
2014 	  Example: Inject netdevice mtu change error (-22 = -EINVAL)
2016 	  # cd /sys/kernel/debug/notifier-error-inject/netdev
2017 	  # echo -22 > actions/NETDEV_CHANGEMTU/error
2022 	  be called netdev-notifier-error-inject.
2027 	bool "Fault-injections of functions"
2037 	bool "Fault-injection framework"
2040 	  Provide fault-injection framework.
2041 	  For more details, see Documentation/fault-injection/.
2044 	bool "Fault-injection capability for kmalloc"
2047 	  Provide fault-injection capability for kmalloc.
2050 	bool "Fault-injection capability for alloc_pages()"
2053 	  Provide fault-injection capability for alloc_pages().
2059 	  Provides fault-injection capability to inject failures
2063 	bool "Fault-injection capability for disk IO"
2066 	  Provide fault-injection capability for disk IO.
2069 	bool "Fault-injection capability for faking disk interrupts"
2072 	  Provide fault-injection capability on end IO handling. This
2080 	bool "Fault-injection capability for futexes"
2084 	  Provide fault-injection capability for futexes.
2087 	bool "Debugfs entries for fault-injection capabilities"
2090 	  Enable configuration of fault-injection capabilities via debugfs.
2093 	bool "Fault-injection capability for functions"
2096 	  Provide function-based fault-injection capability.
2103 	bool "Fault-injection capability for MMC IO"
2106 	  Provide fault-injection capability for MMC IO.
2113 	bool "Fault-injection capability for SunRPC"
2116 	  Provide fault-injection capability for SunRPC and
2120 	bool "Fault-injection capability forcing skb to reallocate"
2123 	  Provide fault-injection capability that forces the skb to be
2127 	  Documentation/fault-injection/fault-injection.rst
2130 	bool "Configfs interface for fault-injection capabilities"
2134 	  This option allows configfs-based drivers to dynamically configure
2135 	  fault-injection via configfs.  Each parameter for driver-specific
2136 	  fault-injection can be made visible as a configfs attribute in a
2141 	bool "stacktrace filter for fault-injection capabilities"
2147 	  Provide stacktrace filter for fault-injection capabilities
2157 	def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2171 	  for coverage-guided fuzzing (randomized testing).
2173 	  For more details, see Documentation/dev-tools/kcov.rst.
2178 	depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2201 	  KCOV uses preallocated per-cpu areas to collect coverage from
2229 	  the kernel command line (when built-in), or from userspace (when
2230 	  built-in or modular).
2265 	Documentation/fault-injection/provoke-crashes.rst
2275 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2301 	tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2305 	  This option enables the self-test function of 'sort()' at boot,
2393 	tristate "Red-Black tree test"
2400 	tristate "Reed-Solomon library test"
2406 	  This option enables the self-test function of rslib at boot,
2422 	  Enable this option to build test module which validates per-cpu
2428 	tristate "Perform an atomic64_t self-test"
2440 	  This is a one-shot self test that permutes through the
2442 	  N-disk array.  Recovery is performed with the asynchronous
2528 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2568 	  no compiler warnings from C=1 sparse checker or -Wextra
2615 	  actual firmware-using device. The contents can be rechecked by
2643 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2660 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2677 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2695 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2697 	  This is intended to help people writing architecture-specific
2709 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2721 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2735 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2740 	tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2754 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2767 	  in Documentation/dev-tools/kunit/.
2779 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2791 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2803 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2815 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2826 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2837 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2849 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2862 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2871 	  Test if the kernel is zero-initializing stack variables and
2872 	  padding. Coverage is controlled by compiler flags,
2917 	  This is intended to help people writing architecture-specific
2934 	  This is intended to help people writing architecture-specific
3006 	  tools/testing/selftests/kmod/kmod.sh --help
3150 	  virt_to_phys() done against the non-linear part of the
3174 	  Test if the kernel is zero-initializing heap and page allocations.
3188 	  Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
3207 	  for self-testing floating point control register setting in
3318 	        memtest=0, mean disabled; -- default
3327 	bool "Microsoft Hyper-V driver testing"
3331 	  Select this option to enable Hyper-V vmbus testing.
3341 	  Enables rustc's `-Cdebug-assertions` codegen option.
3357 	  Enables rustc's `-Coverflow-checks` codegen option.
3360 	  overflow. When overflow-checks are enabled, a Rust panic will occur
3368 	bool "Allow unoptimized build-time assertions"
3392 	  please refer to the KUnit documentation in Documentation/dev-tools/kunit/.