linux/lib/Kconfig.debug

1 # SPDX-License-Identifier: GPL-2.0-only
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()
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,
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"
237 	def_bool $(as-instr,.uleb128 .Lexpr_end4 - .Lexpr_start3\n.Lexpr_start3:\n.Lexpr_end4:)
245 	  This adds debug symbols to the kernel and modules (gcc -g), and
288 	  5.0+ accepts the -gdwarf-5 flag but only had partial support for some
292 	  15-18% savings in resulting image and debug info section sizes as
330 	depends on $(cc-option,-gz=zlib)
331 	depends on $(ld-option,--compress-debug-sections=zlib)
336 	  Users of dpkg-deb via scripts/package/builddeb may find an increase in
345 	depends on $(cc-option,-gz=zstd)
346 	depends on $(ld-option,--compress-debug-sections=zstd)
357 	depends on $(cc-option,-gsplit-dwarf)
358 	# RISC-V linker relaxation + -gsplit-dwarf has issues with LLVM and GCC
360 	# https://github.com/llvm/llvm-project/issues/56642
400 	  Support for the --lang_exclude flag which makes pahole exclude
414 	bool "Allow loading modules with non-matching BTF type info"
430 	  instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
451 	bool "Strip assembler-generated symbols during link"
454 	  Strip internal assembler-generated symbols during a link (symbols
472 	  This option will install uapi headers (headers exported to user-space)
475 	  user-space program samples. It is also needed by some features such
493 	  - Add the option -fno-inline-functions-called-once to gcc commands.
494 	    When inlining a function annotated with __init in a non-init
501 	bool "Make section mismatch errors non-fatal"
543 	bool "Compile-time stack metadata validation"
548 	  Validate frame pointer rules at compile-time.  This helps ensure that
564 	  Selecting this option will pass "-Map=vmlinux.map" to ld
571 	bool "Force weak per-cpu definitions"
600 	  keys are documented in <file:Documentation/admin-guide/sysrq.rst>.
610 	  to a bitmask as described in Documentation/admin-guide/sysrq.rst.
651 	  debugfs=[on,no-mount,off]. The restrictions apply for API access
670 	  Access is off. Clients get -PERM when trying to create nodes in
672 	  Client can then back-off or continue without debugfs access.
712 	  properly. This can make kmalloc/kfree-intensive workloads
746 	int "debug_objects bootup default value (0-1)"
766 	  task has ever had available in the sysrq-T and sysrq-P debug output.
795 	  Enable this to turn on extended checks in the virtual-memory system
820 	bool "Debug VM red-black trees"
823 	  Enable VM red-black tree debugging information and extra validations.
828 	bool "Debug page-flags operations"
878 	  on the mminit_loglevel= command-line option.
886 	  This option provides the ability to inject artificial errors to
888 	  debugfs interface under /sys/kernel/debug/notifier-error-inject/memory
893 	  Example: Inject memory hotplug offline error (-12 == -ENOMEM)
895 	  # cd /sys/kernel/debug/notifier-error-inject/memory
896 	  # echo -12 > actions/MEM_GOING_OFFLINE/error
901 	  be called memory-notifier-error-inject.
933 	  mechanism for non-highmem pages and on non-highmem systems.
957 	  These kinds of bugs usually occur when call-chains in the
1039 	  high-availability systems that have uptime guarantees and
1078 # Note that arch-specific variants are always preferred.
1093 	  an arch-specific hardlockup detector or if resources needed
1116 	  The arch-specific implementation of the hardlockup detector will
1166 	  to determine when a task has become non-responsive and should
1187 	  high-availability systems that have uptime guarantees and
1204 	bool "Report per-cpu work items which hog CPU for too long"
1207 	  Say Y here to enable reporting of concurrency-managed per-cpu work
1211 	  them from stalling other per-cpu work items. Occassional
1225 	  Also it could generate series of lockups with cooling-down periods.
1280 	  if kernel code uses it in a preemption-unsafe way. Also, the kernel
1321 	 participant CPUs, tasks and irq-contexts would be needed
1334 	 and rwsems - in which case all dependencies between these
1339 	 For more details, see Documentation/locking/lockdep-design.rst.
1342 	bool "Enable raw_spinlock - spinlock nesting checks"
1388 	bool "Spinlock and rw-lock debugging: basic checks"
1413 	 injecting additional -EDEADLK wound/backoff cases. Together with
1439 	 memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
1492 … Try increasing this value if you hit "lockdep bfs error:-1" warning due to __cq_enqueue() failure.
1515 	bool "Locking API boot-time self-tests"
1518 	  Say Y here if you want the kernel to run a short self-test during
1519 	  bootup. The self-test checks whether common types of locking bugs
1534 	  Say Y here if you want kernel locking-primitive torture tests
1685 	  Enable this to turn on extended checks in the linked-list walking
1698 	  Enable this to turn on extended checks in the priority-ordered
1699 	  linked-list (plist) walking routines.  This checks the entire
1708 	  Enable this to turn on checks on scatter-gather tables. This can
1737 	bool "Force round-robin CPU selection for unbound work items"
1746 	  round-robin CPU selection to flush out usages which depend on the
1815 	  in charge of the OHCI-1394 controllers should be used instead.
1817 	  See Documentation/core-api/debugging-via-ohci1394.rst for more information.
1849 	  io-memory regardless of whether a driver is actively using that
1854 	  userspace access to *idle* io-memory ranges (see /proc/iomem) This
1875 	  This option provides the ability to inject artificial errors to
1886 	  This option provides the ability to inject artificial errors to
1888 	  interface /sys/kernel/debug/notifier-error-inject/pm
1893 	  Example: Inject PM suspend error (-12 = -ENOMEM)
1895 	  # cd /sys/kernel/debug/notifier-error-inject/pm/
1896 	  # echo -12 > actions/PM_SUSPEND_PREPARE/error
1901 	  be called pm-notifier-error-inject.
1909 	  This option provides the ability to inject artificial errors to
1912 	  /sys/kernel/debug/notifier-error-inject/OF-reconfig/
1918 	  be called of-reconfig-notifier-error-inject.
1926 	  This option provides the ability to inject artificial errors to
1928 	  interface /sys/kernel/debug/notifier-error-inject/netdev
1933 	  Example: Inject netdevice mtu change error (-22 = -EINVAL)
1935 	  # cd /sys/kernel/debug/notifier-error-inject/netdev
1936 	  # echo -22 > actions/NETDEV_CHANGEMTU/error
1941 	  be called netdev-notifier-error-inject.
1946 	bool "Fault-injections of functions"
1949 	  Add fault injections into various functions that are annotated with
1956 	bool "Fault-injection framework"
1959 	  Provide fault-injection framework.
1960 	  For more details, see Documentation/fault-injection/.
1963 	bool "Fault-injection capability for kmalloc"
1967 	  Provide fault-injection capability for kmalloc.
1970 	bool "Fault-injection capability for alloc_pages()"
1973 	  Provide fault-injection capability for alloc_pages().
1976 	bool "Fault injection capability for usercopy functions"
1979 	  Provides fault-injection capability to inject failures
1983 	bool "Fault-injection capability for disk IO"
1986 	  Provide fault-injection capability for disk IO.
1989 	bool "Fault-injection capability for faking disk interrupts"
1992 	  Provide fault-injection capability on end IO handling. This
2000 	bool "Fault-injection capability for futexes"
2004 	  Provide fault-injection capability for futexes.
2007 	bool "Debugfs entries for fault-injection capabilities"
2010 	  Enable configuration of fault-injection capabilities via debugfs.
2013 	bool "Fault-injection capability for functions"
2016 	  Provide function-based fault-injection capability.
2023 	bool "Fault-injection capability for MMC IO"
2026 	  Provide fault-injection capability for MMC IO.
2033 	bool "Fault-injection capability for SunRPC"
2036 	  Provide fault-injection capability for SunRPC and
2040 	bool "Configfs interface for fault-injection capabilities"
2044 	  This option allows configfs-based drivers to dynamically configure
2045 	  fault-injection via configfs.  Each parameter for driver-specific
2046 	  fault-injection can be made visible as a configfs attribute in a
2051 	bool "stacktrace filter for fault-injection capabilities"
2057 	  Provide stacktrace filter for fault-injection capabilities
2067 	def_bool $(cc-option,-fsanitize-coverage=trace-pc)
2081 	  for coverage-guided fuzzing (randomized testing).
2087 	  For more details, see Documentation/dev-tools/kcov.rst.
2092 	depends on $(cc-option,-fsanitize-coverage=trace-cmp)
2115 	  KCOV uses preallocated per-cpu areas to collect coverage from
2135 	  the kernel command line (when built-in), or from userspace (when
2136 	  built-in or modular.
2171 	Documentation/fault-injection/provoke-crashes.rst
2181 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2207 	tristate "Array-based sort test" if !KUNIT_ALL_TESTS
2211 	  This option enables the self-test function of 'sort()' at boot,
2289 	tristate "Red-Black tree test"
2296 	tristate "Reed-Solomon library test"
2302 	  This option enables the self-test function of rslib at boot,
2318 	  Enable this option to build test module which validates per-cpu
2324 	tristate "Perform an atomic64_t self-test"
2336 	  This is a one-shot self test that permutes through the
2338 	  N-disk array.  Recovery is performed with the asynchronous
2431 	  no compiler warnings from C=1 sparse checker or -Wextra
2499 	  actual firmware-using device. The contents can be rechecked by
2527 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2544 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2562 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2564 	  This is intended to help people writing architecture-specific
2575 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2587 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2592 	tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
2606 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2619 	  in Documentation/dev-tools/kunit/.
2631 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2643 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2655 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2667 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2678 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2689 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2713 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2726 	  to the KUnit documentation in Documentation/dev-tools/kunit/.
2735 	  Test if the kernel is zero-initializing stack variables and
2778 	  This is intended to help people writing architecture-specific
2830 	  tools/testing/selftests/kmod/kmod.sh --help
2839 	  virt_to_phys() done against the non-linear part of the
2864 	  make -C tools/testing/selftests TARGETS=livepatch run_tests
2868 	  tools/testing/selftests/livepatch/test-callbacks.sh
2869 	  tools/testing/selftests/livepatch/test-livepatch.sh
2870 	  tools/testing/selftests/livepatch/test-shadow-vars.sh
2885 	  Test if the kernel is zero-initializing heap and page allocations.
2899 	  Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
2918 	  for self-testing floating point control register setting in
2949 	        memtest=0, mean disabled; -- default
2958 	bool "Microsoft Hyper-V driver testing"
2962 	  Select this option to enable Hyper-V vmbus testing.
2972 	  Enables rustc's `-Cdebug-assertions` codegen option.
2988 	  Enables rustc's `-Coverflow-checks` codegen option.
2991 	  overflow. When overflow-checks are enabled, a Rust panic will occur
2999 	bool "Allow unoptimized build-time assertions"
3023 	  please refer to the KUnit documentation in Documentation/dev-tools/kunit/.