Commit e61aca51 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'kconfig-diet' from Dave Hansen

Merge Kconfig menu diet patches from Dave Hansen:
 "I think the "Kernel Hacking" menu has gotten a bit out of hand.  It is
  over 120 lines long on my system with everything enabled and options
  are scattered around it haphazardly.

        http://sr71.net/~dave/linux/kconfig-horror.png

  Let's try to introduce some sanity.  This set takes that 120 lines
  down to 55 and makes it vastly easier to find some things.  It's a
  start.

  This set stands on its own, but there is plenty of room for follow-up
  patches.  The arch-specific debug options still end up getting stuck
  in the top-level "kernel hacking" menu.  OPTIMIZE_INLINING, for
  instance, could obviously go in to the "compiler options" menu, but
  the fact that it is defined in arch/ in a separate Kconfig file keeps
  it on its own for the moment.

  The Signed-off-by's in here look funky.  I changed employers while
  working on this set, so I have signoffs from both email addresses"

* emailed patches from Dave Hansen <dave@sr71.net>:
  hang and lockup detection menu
  kconfig: consolidate printk options
  group locking debugging options
  consolidate compilation option configs
  consolidate runtime testing configs
  order memory debugging Kconfig options
  consolidate per-arch stack overflow debugging options
parents da67db4e 92aef8fb
...@@ -34,6 +34,7 @@ config ARC ...@@ -34,6 +34,7 @@ config ARC
select OF select OF
select OF_EARLY_FLATTREE select OF_EARLY_FLATTREE
select PERF_USE_VMALLOC select PERF_USE_VMALLOC
select HAVE_DEBUG_STACKOVERFLOW
config SCHED_OMIT_FRAME_POINTER config SCHED_OMIT_FRAME_POINTER
def_bool y def_bool y
......
...@@ -15,13 +15,6 @@ config EARLY_PRINTK ...@@ -15,13 +15,6 @@ config EARLY_PRINTK
with klogd/syslogd or the X server. You should normally N here, with klogd/syslogd or the X server. You should normally N here,
unless you want to debug such a crash. unless you want to debug such a crash.
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
help
This option will cause messages to be printed if free stack space
drops below a certain limit.
config 16KSTACKS config 16KSTACKS
bool "Use 16Kb for kernel stacks instead of 8Kb" bool "Use 16Kb for kernel stacks instead of 8Kb"
help help
......
...@@ -41,6 +41,7 @@ config BLACKFIN ...@@ -41,6 +41,7 @@ config BLACKFIN
select ARCH_USES_GETTIMEOFFSET if !GENERIC_CLOCKEVENTS select ARCH_USES_GETTIMEOFFSET if !GENERIC_CLOCKEVENTS
select HAVE_MOD_ARCH_SPECIFIC select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_RELA select MODULES_USE_ELF_RELA
select HAVE_DEBUG_STACKOVERFLOW
config GENERIC_CSUM config GENERIC_CSUM
def_bool y def_bool y
......
...@@ -2,13 +2,6 @@ menu "Kernel hacking" ...@@ -2,13 +2,6 @@ menu "Kernel hacking"
source "lib/Kconfig.debug" source "lib/Kconfig.debug"
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
help
This option will cause messages to be printed if free stack space
drops below a certain limit.
config DEBUG_VERBOSE config DEBUG_VERBOSE
bool "Verbose fault messages" bool "Verbose fault messages"
default y default y
......
...@@ -14,6 +14,7 @@ config FRV ...@@ -14,6 +14,7 @@ config FRV
select ARCH_WANT_IPC_PARSE_VERSION select ARCH_WANT_IPC_PARSE_VERSION
select OLD_SIGSUSPEND3 select OLD_SIGSUSPEND3
select OLD_SIGACTION select OLD_SIGACTION
select HAVE_DEBUG_STACKOVERFLOW
config ZONE_DMA config ZONE_DMA
bool bool
......
...@@ -2,10 +2,6 @@ menu "Kernel hacking" ...@@ -2,10 +2,6 @@ menu "Kernel hacking"
source "lib/Kconfig.debug" source "lib/Kconfig.debug"
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
config GDBSTUB config GDBSTUB
bool "Remote GDB kernel debugging" bool "Remote GDB kernel debugging"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
......
...@@ -16,6 +16,7 @@ config M32R ...@@ -16,6 +16,7 @@ config M32R
select GENERIC_ATOMIC64 select GENERIC_ATOMIC64
select ARCH_USES_GETTIMEOFFSET select ARCH_USES_GETTIMEOFFSET
select MODULES_USE_ELF_RELA select MODULES_USE_ELF_RELA
select HAVE_DEBUG_STACKOVERFLOW
config SBUS config SBUS
bool bool
......
...@@ -2,13 +2,6 @@ menu "Kernel hacking" ...@@ -2,13 +2,6 @@ menu "Kernel hacking"
source "lib/Kconfig.debug" source "lib/Kconfig.debug"
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
help
This option will cause messages to be printed if free stack space
drops below a certain limit.
config DEBUG_PAGEALLOC config DEBUG_PAGEALLOC
bool "Debug page memory allocations" bool "Debug page memory allocations"
depends on DEBUG_KERNEL && BROKEN depends on DEBUG_KERNEL && BROKEN
......
...@@ -30,6 +30,7 @@ config METAG ...@@ -30,6 +30,7 @@ config METAG
select OF select OF
select OF_EARLY_FLATTREE select OF_EARLY_FLATTREE
select SPARSE_IRQ select SPARSE_IRQ
select HAVE_DEBUG_STACKOVERFLOW
config STACKTRACE_SUPPORT config STACKTRACE_SUPPORT
def_bool y def_bool y
......
...@@ -6,13 +6,6 @@ config TRACE_IRQFLAGS_SUPPORT ...@@ -6,13 +6,6 @@ config TRACE_IRQFLAGS_SUPPORT
source "lib/Kconfig.debug" source "lib/Kconfig.debug"
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
help
This option will cause messages to be printed if free stack space
drops below a certain limit.
config 4KSTACKS config 4KSTACKS
bool "Use 4Kb for kernel stacks instead of 8Kb" bool "Use 4Kb for kernel stacks instead of 8Kb"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
......
...@@ -42,6 +42,7 @@ config MIPS ...@@ -42,6 +42,7 @@ config MIPS
select MODULES_USE_ELF_REL if MODULES select MODULES_USE_ELF_REL if MODULES
select MODULES_USE_ELF_RELA if MODULES && 64BIT select MODULES_USE_ELF_RELA if MODULES && 64BIT
select CLONE_BACKWARDS select CLONE_BACKWARDS
select HAVE_DEBUG_STACKOVERFLOW
menu "Machine selection" menu "Machine selection"
......
...@@ -67,15 +67,6 @@ config CMDLINE_OVERRIDE ...@@ -67,15 +67,6 @@ config CMDLINE_OVERRIDE
Normally, you will choose 'N' here. Normally, you will choose 'N' here.
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
help
This option will cause messages to be printed if free stack space
drops below a certain limit(2GB on MIPS). The debugging option
provides another way to check stack overflow happened on kernel mode
stack usually caused by nested interruption.
config SMTC_IDLE_HOOK_DEBUG config SMTC_IDLE_HOOK_DEBUG
bool "Enable additional debug checks before going into CPU idle loop" bool "Enable additional debug checks before going into CPU idle loop"
depends on DEBUG_KERNEL && MIPS_MT_SMTC depends on DEBUG_KERNEL && MIPS_MT_SMTC
......
...@@ -13,6 +13,7 @@ config MN10300 ...@@ -13,6 +13,7 @@ config MN10300
select MODULES_USE_ELF_RELA select MODULES_USE_ELF_RELA
select OLD_SIGSUSPEND3 select OLD_SIGSUSPEND3
select OLD_SIGACTION select OLD_SIGACTION
select HAVE_DEBUG_STACKOVERFLOW
config AM33_2 config AM33_2
def_bool n def_bool n
......
...@@ -2,10 +2,6 @@ menu "Kernel hacking" ...@@ -2,10 +2,6 @@ menu "Kernel hacking"
source "lib/Kconfig.debug" source "lib/Kconfig.debug"
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
config DEBUG_DECOMPRESS_KERNEL config DEBUG_DECOMPRESS_KERNEL
bool "Using serial port during decompressing kernel" bool "Using serial port during decompressing kernel"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
......
...@@ -22,6 +22,7 @@ config OPENRISC ...@@ -22,6 +22,7 @@ config OPENRISC
select GENERIC_STRNCPY_FROM_USER select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER select GENERIC_STRNLEN_USER
select MODULES_USE_ELF_RELA select MODULES_USE_ELF_RELA
select HAVE_DEBUG_STACKOVERFLOW
config MMU config MMU
def_bool y def_bool y
...@@ -128,16 +129,6 @@ config CMDLINE ...@@ -128,16 +129,6 @@ config CMDLINE
menu "Debugging options" menu "Debugging options"
config DEBUG_STACKOVERFLOW
bool "Check for kernel stack overflow"
default y
help
Make extra checks for space available on stack in some
critical functions. This will cause kernel to run a bit slower,
but will catch most of kernel stack overruns and exit gracefully.
Say Y if you are unsure.
config JUMP_UPON_UNHANDLED_EXCEPTION config JUMP_UPON_UNHANDLED_EXCEPTION
bool "Try to die gracefully" bool "Try to die gracefully"
default y default y
......
...@@ -27,6 +27,7 @@ config PARISC ...@@ -27,6 +27,7 @@ config PARISC
select MODULES_USE_ELF_RELA select MODULES_USE_ELF_RELA
select CLONE_BACKWARDS select CLONE_BACKWARDS
select TTY # Needed for pdc_cons.c select TTY # Needed for pdc_cons.c
select HAVE_DEBUG_STACKOVERFLOW
help help
The PA-RISC microprocessor is designed by Hewlett-Packard and used The PA-RISC microprocessor is designed by Hewlett-Packard and used
......
...@@ -13,14 +13,3 @@ config DEBUG_RODATA ...@@ -13,14 +13,3 @@ config DEBUG_RODATA
If in doubt, say "N". If in doubt, say "N".
endmenu endmenu
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
default y
depends on DEBUG_KERNEL
---help---
Say Y here if you want to check the overflows of kernel, IRQ
and exception stacks. This option will cause messages of the
stacks in detail when free stack space drops below a certain
limit.
If in doubt, say "N".
...@@ -138,6 +138,7 @@ config PPC ...@@ -138,6 +138,7 @@ config PPC
select ARCH_USE_BUILTIN_BSWAP select ARCH_USE_BUILTIN_BSWAP
select OLD_SIGSUSPEND select OLD_SIGSUSPEND
select OLD_SIGACTION if PPC32 select OLD_SIGACTION if PPC32
select HAVE_DEBUG_STACKOVERFLOW
config EARLY_PRINTK config EARLY_PRINTK
bool bool
......
...@@ -28,13 +28,6 @@ config PRINT_STACK_DEPTH ...@@ -28,13 +28,6 @@ config PRINT_STACK_DEPTH
too small and stack traces cause important information to too small and stack traces cause important information to
scroll off the screen. scroll off the screen.
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
help
This option will cause messages to be printed if free stack space
drops below a certain limit.
config HCALL_STATS config HCALL_STATS
bool "Hypervisor call instrumentation" bool "Hypervisor call instrumentation"
depends on PPC_PSERIES && DEBUG_FS && TRACEPOINTS depends on PPC_PSERIES && DEBUG_FS && TRACEPOINTS
......
...@@ -25,6 +25,7 @@ config TILE ...@@ -25,6 +25,7 @@ config TILE
select HAVE_ARCH_TRACEHOOK select HAVE_ARCH_TRACEHOOK
select HAVE_SYSCALL_TRACEPOINTS select HAVE_SYSCALL_TRACEPOINTS
select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
select HAVE_DEBUG_STACKOVERFLOW
# FIXME: investigate whether we need/want these options. # FIXME: investigate whether we need/want these options.
# select HAVE_IOREMAP_PROT # select HAVE_IOREMAP_PROT
......
...@@ -14,13 +14,6 @@ config EARLY_PRINTK ...@@ -14,13 +14,6 @@ config EARLY_PRINTK
with klogd/syslogd. You should normally N here, with klogd/syslogd. You should normally N here,
unless you want to debug such a crash. unless you want to debug such a crash.
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
help
This option will cause messages to be printed if free stack space
drops below a certain limit.
config DEBUG_EXTRA_FLAGS config DEBUG_EXTRA_FLAGS
string "Additional compiler arguments when building with '-g'" string "Additional compiler arguments when building with '-g'"
depends on DEBUG_INFO depends on DEBUG_INFO
......
...@@ -122,6 +122,7 @@ config X86 ...@@ -122,6 +122,7 @@ config X86
select OLD_SIGACTION if X86_32 select OLD_SIGACTION if X86_32
select COMPAT_OLD_SIGACTION if IA32_EMULATION select COMPAT_OLD_SIGACTION if IA32_EMULATION
select RTC_LIB select RTC_LIB
select HAVE_DEBUG_STACKOVERFLOW
config INSTRUCTION_DECODER config INSTRUCTION_DECODER
def_bool y def_bool y
......
...@@ -59,16 +59,6 @@ config EARLY_PRINTK_DBGP ...@@ -59,16 +59,6 @@ config EARLY_PRINTK_DBGP
with klogd/syslogd or the X server. You should normally N here, with klogd/syslogd or the X server. You should normally N here,
unless you want to debug such a crash. You need usb debug device. unless you want to debug such a crash. You need usb debug device.
config DEBUG_STACKOVERFLOW
bool "Check for stack overflows"
depends on DEBUG_KERNEL
---help---
Say Y here if you want to check the overflows of kernel, IRQ
and exception stacks. This option will cause messages of the
stacks in detail when free stack space drops below a certain
limit.
If in doubt, say "N".
config X86_PTDUMP config X86_PTDUMP
bool "Export kernel pagetable layout to userspace via debugfs" bool "Export kernel pagetable layout to userspace via debugfs"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
......
menu "printk and dmesg options"
config PRINTK_TIME config PRINTK_TIME
bool "Show timing information on printks" bool "Show timing information on printks"
...@@ -25,6 +26,123 @@ config DEFAULT_MESSAGE_LOGLEVEL ...@@ -25,6 +26,123 @@ config DEFAULT_MESSAGE_LOGLEVEL
that are auditing their logs closely may want to set it to a lower that are auditing their logs closely may want to set it to a lower
priority. priority.
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/dynamic-debug-howto.txt 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
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 ENABLE_WARN_DEPRECATED config ENABLE_WARN_DEPRECATED
bool "Enable __deprecated logic" bool "Enable __deprecated logic"
default y default y
...@@ -52,20 +170,6 @@ config FRAME_WARN ...@@ -52,20 +170,6 @@ config FRAME_WARN
Setting it to 0 disables the warning. Setting it to 0 disables the warning.
Requires gcc 4.4 Requires gcc 4.4
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/sysrq.txt>. Don't say Y
unless you really know what this hack does.
config STRIP_ASM_SYMS config STRIP_ASM_SYMS
bool "Strip assembler-generated symbols during link" bool "Strip assembler-generated symbols during link"
default n default n
...@@ -156,222 +260,90 @@ config DEBUG_SECTION_MISMATCH ...@@ -156,222 +260,90 @@ config DEBUG_SECTION_MISMATCH
- Enable verbose reporting from modpost in order to help resolve - Enable verbose reporting from modpost in order to help resolve
the section mismatches that are reported. the section mismatches that are reported.
config DEBUG_KERNEL #
bool "Kernel debugging" # 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
help help
Say Y here if you are developing drivers or trying to debug and
identify kernel problems.
config DEBUG_SHIRQ config FRAME_POINTER
bool "Debug shared IRQ handlers" bool "Compile the kernel with frame pointers"
depends on DEBUG_KERNEL && GENERIC_HARDIRQS depends on DEBUG_KERNEL && \
(CRIS || M68K || FRV || UML || \
AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || \
ARCH_WANT_FRAME_POINTERS
default y if (DEBUG_INFO && UML) || ARCH_WANT_FRAME_POINTERS
help help
Enable this to generate a spurious interrupt as soon as a shared If you say Y here the resulting kernel image will be slightly
interrupt handler is registered, and just before one is deregistered. larger and slower, but it gives very useful debugging information
Drivers ought to be able to handle interrupts coming in at those in case of kernel bugs. (precise oopses/stacktraces/warnings)
points; some don't and need to be caught.
config LOCKUP_DETECTOR config DEBUG_FORCE_WEAK_PER_CPU
bool "Detect Hard and Soft Lockups" bool "Force weak per-cpu definitions"
depends on DEBUG_KERNEL && !S390 depends on DEBUG_KERNEL
help help
Say Y here to enable the kernel to act as a watchdog to detect s390 and alpha require percpu variables in modules to be
hard and soft lockups. defined weak to work around addressing range issue which
puts the following two restrictions on percpu variable
Softlockups are bugs that cause the kernel to loop in kernel definitions.
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.
Hardlockups are bugs that cause the CPU to loop in kernel mode 1. percpu symbols must be unique whether static or not
for more than 10 seconds, without letting other interrupts have a 2. percpu variables can't be defined inside a function
chance to run. The current stack trace is displayed upon detection
and the system will stay locked up.
The overhead should be minimal. A periodic hrtimer runs to To ensure that generic code follows the above rules, this
generate interrupts and kick the watchdog task every 4 seconds. option forces all percpu variables to be defined as weak.
An NMI is generated every 10 seconds or so to check for hardlockups.
The frequency of hrtimer and NMI events and the soft and hard lockup endmenu # "Compiler options"
thresholds can be controlled through the sysctl watchdog_thresh.
config HARDLOCKUP_DETECTOR config MAGIC_SYSRQ
def_bool y bool "Magic SysRq key"
depends on LOCKUP_DETECTOR && !HAVE_NMI_WATCHDOG depends on !UML
depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI 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/sysrq.txt>. Don't say Y
unless you really know what this hack does.
config BOOTPARAM_HARDLOCKUP_PANIC config DEBUG_KERNEL
bool "Panic (Reboot) On Hard Lockups" bool "Kernel debugging"
depends on HARDLOCKUP_DETECTOR
help help
Say Y here to enable the kernel to panic on "hard lockups", Say Y here if you are developing drivers or trying to debug and
which are bugs that cause the kernel to loop in kernel identify kernel problems.
mode with interrupts disabled for more than 10 seconds (configurable
using the watchdog_thresh sysctl).
Say N if unsure. menu "Memory Debugging"
config BOOTPARAM_HARDLOCKUP_PANIC_VALUE source mm/Kconfig.debug
int
depends on HARDLOCKUP_DETECTOR
range 0 1
default 0 if !BOOTPARAM_HARDLOCKUP_PANIC
default 1 if BOOTPARAM_HARDLOCKUP_PANIC
config BOOTPARAM_SOFTLOCKUP_PANIC config DEBUG_OBJECTS
bool "Panic (Reboot) On Soft Lockups" bool "Debug object operations"
depends on LOCKUP_DETECTOR depends on DEBUG_KERNEL
help help
Say Y here to enable the kernel to panic on "soft lockups", If you say Y here, additional code will be inserted into the
which are bugs that cause the kernel to loop in kernel kernel to track the life time of various objects and validate
mode for more than 20 seconds (configurable using the watchdog_thresh the operations on those objects.
sysctl), without giving other tasks a chance to run.
The panic can be used in combination with panic_timeout, config DEBUG_OBJECTS_SELFTEST
to cause the system to reboot automatically after a bool "Debug objects selftest"
lockup has been detected. This feature is useful for depends on DEBUG_OBJECTS
high-availability systems that have uptime guarantees and help
where a lockup must be resolved ASAP. This enables the selftest of the object debug code.
Say N if unsure. config DEBUG_OBJECTS_FREE
bool "Debug objects in freed memory"
config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE depends on DEBUG_OBJECTS
int help
depends on LOCKUP_DETECTOR This enables checks whether a k/v free operation frees an area
range 0 1 which contains an object which has not been deactivated
default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC properly. This can make kmalloc/kfree-intensive workloads
default 1 if BOOTPARAM_SOFTLOCKUP_PANIC much slower.
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 DETECT_HUNG_TASK
bool "Detect Hung Tasks"
depends on DEBUG_KERNEL
default LOCKUP_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 indefinitiley.
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 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 SCHEDSTATS
bool "Collect scheduler statistics"
depends on DEBUG_KERNEL && PROC_FS
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 TIMER_STATS
bool "Collect kernel timers statistics"
depends on DEBUG_KERNEL && PROC_FS
help
If you say Y here, additional code will be inserted into the
timer routines to collect statistics about kernel timers being
reprogrammed. The statistics can be read from /proc/timer_stats.
The statistics collection is started by writing 1 to /proc/timer_stats,
writing 0 stops it. This feature is useful to collect information
about timer usage patterns in kernel and userspace. This feature
is lightweight if enabled in the kernel config but not activated
(it defaults to deactivated on bootup and will only be activated
if some application like powertop activates it explicitly).
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 config DEBUG_OBJECTS_TIMERS
bool "Debug timer objects" bool "Debug timer objects"
...@@ -469,38 +441,351 @@ config DEBUG_KMEMLEAK ...@@ -469,38 +441,351 @@ config DEBUG_KMEMLEAK
allocations. See Documentation/kmemleak.txt for more allocations. See Documentation/kmemleak.txt for more
details. details.
Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances
of finding leaks due to the slab objects poisoning. 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_EARLY_LOG_SIZE
int "Maximum kmemleak early log entries"
depends on DEBUG_KMEMLEAK
range 200 40000
default 400
help
Kmemleak must track all the memory allocations to avoid
reporting false positives. Since memory may be allocated or
freed before kmemleak is initialised, an early log buffer is
used to store these actions. If kmemleak reports "early log
buffer exceeded", please increase this value.
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_STACK_USAGE
bool "Stack utilization instrumentation"
depends on DEBUG_KERNEL && !IA64 && !PARISC && !METAG
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_RB
bool "Debug VM red-black trees"
depends on DEBUG_VM
help
Enable this to turn on more extended checks in the virtual-memory
system that may impact performance.
If unsure, say N.
config DEBUG_VIRTUAL
bool "Debug VM translations"
depends on DEBUG_KERNEL && X86
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 options enables addition 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 archicture 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.kmemcheck"
endmenu # "Memory Debugging"
config DEBUG_SHIRQ
bool "Debug shared IRQ handlers"
depends on DEBUG_KERNEL && GENERIC_HARDIRQS
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 "Detect Hard and Soft Lockups"
depends on DEBUG_KERNEL && !S390
help
Say Y here to enable the kernel to act as a watchdog to detect
hard and 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.
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.
The overhead should be minimal. A periodic hrtimer runs to
generate interrupts and kick the watchdog task every 4 seconds.
An NMI is generated every 10 seconds or so to check for hardlockups.
The frequency of hrtimer and NMI events and the soft and hard lockup
thresholds can be controlled through the sysctl watchdog_thresh.
config HARDLOCKUP_DETECTOR
def_bool y
depends on LOCKUP_DETECTOR && !HAVE_NMI_WATCHDOG
depends on PERF_EVENTS && HAVE_PERF_EVENTS_NMI
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 BOOTPARAM_SOFTLOCKUP_PANIC
bool "Panic (Reboot) On Soft Lockups"
depends on LOCKUP_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 LOCKUP_DETECTOR
range 0 1
default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
config DETECT_HUNG_TASK
bool "Detect Hung Tasks"
depends on DEBUG_KERNEL
default LOCKUP_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 indefinitiley.
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.
In order to access the kmemleak file, debugfs needs to be config BOOTPARAM_HUNG_TASK_PANIC_VALUE
mounted (usually at /sys/kernel/debug). int
depends on DETECT_HUNG_TASK
range 0 1
default 0 if !BOOTPARAM_HUNG_TASK_PANIC
default 1 if BOOTPARAM_HUNG_TASK_PANIC
config DEBUG_KMEMLEAK_EARLY_LOG_SIZE endmenu # "Debug lockups and hangs"
int "Maximum kmemleak early log entries"
depends on DEBUG_KMEMLEAK config PANIC_ON_OOPS
range 200 40000 bool "Panic on Oops"
default 400
help help
Kmemleak must track all the memory allocations to avoid Say Y here to enable the kernel to panic when it oopses. This
reporting false positives. Since memory may be allocated or has the same effect as setting oops=panic on the kernel command
freed before kmemleak is initialised, an early log buffer is line.
used to store these actions. If kmemleak reports "early log
buffer exceeded", please increase this value.
config DEBUG_KMEMLEAK_TEST This feature is useful to ensure that the kernel does not do
tristate "Simple test for the kernel memory leak detector" anything erroneous after an oops which could result in data
depends on DEBUG_KMEMLEAK && m 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 SCHED_DEBUG
bool "Collect scheduler debugging info"
depends on DEBUG_KERNEL && PROC_FS
default y
help help
This option enables a module that explicitly leaks memory. 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.
If unsure, say N. config SCHEDSTATS
bool "Collect scheduler statistics"
depends on DEBUG_KERNEL && PROC_FS
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 DEBUG_KMEMLEAK_DEFAULT_OFF config TIMER_STATS
bool "Default kmemleak to off" bool "Collect kernel timers statistics"
depends on DEBUG_KMEMLEAK depends on DEBUG_KERNEL && PROC_FS
help help
Say Y here to disable kmemleak by default. It can then be enabled If you say Y here, additional code will be inserted into the
on the command line via kmemleak=on. timer routines to collect statistics about kernel timers being
reprogrammed. The statistics can be read from /proc/timer_stats.
The statistics collection is started by writing 1 to /proc/timer_stats,
writing 0 stops it. This feature is useful to collect information
about timer usage patterns in kernel and userspace. This feature
is lightweight if enabled in the kernel config but not activated
(it defaults to deactivated on bootup and will only be activated
if some application like powertop activates it explicitly).
config DEBUG_PREEMPT config DEBUG_PREEMPT
bool "Debug preemptible kernel" bool "Debug preemptible kernel"
...@@ -512,6 +797,8 @@ config DEBUG_PREEMPT ...@@ -512,6 +797,8 @@ config DEBUG_PREEMPT
if kernel code uses it in a preemption-unsafe way. Also, the kernel if kernel code uses it in a preemption-unsafe way. Also, the kernel
will detect preemption count underflows. will detect preemption count underflows.
menu "Lock Debugging (spinlocks, mutexes, etc...)"
config DEBUG_RT_MUTEXES config DEBUG_RT_MUTEXES
bool "RT Mutex debugging, deadlock detection" bool "RT Mutex debugging, deadlock detection"
depends on DEBUG_KERNEL && RT_MUTEXES depends on DEBUG_KERNEL && RT_MUTEXES
...@@ -654,12 +941,6 @@ config DEBUG_LOCKDEP ...@@ -654,12 +941,6 @@ config DEBUG_LOCKDEP
additional runtime checks to debug itself, at the price additional runtime checks to debug itself, at the price
of more runtime overhead. of more runtime overhead.
config TRACE_IRQFLAGS
bool
help
Enables hooks to interrupt enabling and disabling for
either tracing or lock debugging.
config DEBUG_ATOMIC_SLEEP config DEBUG_ATOMIC_SLEEP
bool "Sleep inside atomic section checking" bool "Sleep inside atomic section checking"
select PREEMPT_COUNT select PREEMPT_COUNT
...@@ -681,18 +962,17 @@ config DEBUG_LOCKING_API_SELFTESTS ...@@ -681,18 +962,17 @@ config DEBUG_LOCKING_API_SELFTESTS
The following locking APIs are covered: spinlocks, rwlocks, The following locking APIs are covered: spinlocks, rwlocks,
mutexes and rwsems. mutexes and rwsems.
config STACKTRACE endmenu # lock debugging
bool
depends on STACKTRACE_SUPPORT
config DEBUG_STACK_USAGE config TRACE_IRQFLAGS
bool "Stack utilization instrumentation" bool
depends on DEBUG_KERNEL && !IA64 && !PARISC && !METAG
help help
Enables the display of the minimum amount of free stack which each Enables hooks to interrupt enabling and disabling for
task has ever had available in the sysrq-T and sysrq-P debug output. either tracing or lock debugging.
This option will slow down process creation somewhat. config STACKTRACE
bool
depends on STACKTRACE_SUPPORT
config DEBUG_KOBJECT config DEBUG_KOBJECT
bool "kobject debugging" bool "kobject debugging"
...@@ -701,13 +981,6 @@ config DEBUG_KOBJECT ...@@ -701,13 +981,6 @@ config DEBUG_KOBJECT
If you say Y here, some extra kobject debugging messages will be sent If you say Y here, some extra kobject debugging messages will be sent
to the syslog. to the syslog.
config DEBUG_HIGHMEM
bool "Highmem debugging"
depends on DEBUG_KERNEL && HIGHMEM
help
This options enables addition error checking for high memory systems.
Disable for production systems.
config HAVE_DEBUG_BUGVERBOSE config HAVE_DEBUG_BUGVERBOSE
bool bool
...@@ -720,66 +993,6 @@ config DEBUG_BUGVERBOSE ...@@ -720,66 +993,6 @@ config DEBUG_BUGVERBOSE
of the BUG call as well as the EIP and oops trace. This aids of the BUG call as well as the EIP and oops trace. This aids
debugging but costs about 70-100K of memory. debugging but costs about 70-100K of memory.
config DEBUG_INFO
bool "Compile the kernel with debug info"
depends on DEBUG_KERNEL
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_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_RB
bool "Debug VM red-black trees"
depends on DEBUG_VM
help
Enable this to turn on more extended checks in the virtual-memory
system that may impact performance.
If unsure, say N.
config DEBUG_VIRTUAL
bool "Debug VM translations"
depends on DEBUG_KERNEL && X86
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_WRITECOUNT config DEBUG_WRITECOUNT
bool "Debug filesystem writers count" bool "Debug filesystem writers count"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
...@@ -790,18 +1003,6 @@ config DEBUG_WRITECOUNT ...@@ -790,18 +1003,6 @@ config DEBUG_WRITECOUNT
If unsure, say N. If unsure, say N.
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 DEBUG_LIST config DEBUG_LIST
bool "Debug linked list manipulation" bool "Debug linked list manipulation"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
...@@ -811,15 +1012,6 @@ config DEBUG_LIST ...@@ -811,15 +1012,6 @@ config DEBUG_LIST
If unsure, say N. If unsure, say N.
config TEST_LIST_SORT
bool "Linked list sorting test"
depends on DEBUG_KERNEL
help
Enable this to turn on 'list_sort()' function test. This test is
executed only once during system boot, so affects only boot time.
If unsure, say N.
config DEBUG_SG config DEBUG_SG
bool "Debug SG table operations" bool "Debug SG table operations"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
...@@ -855,45 +1047,6 @@ config DEBUG_CREDENTIALS ...@@ -855,45 +1047,6 @@ config DEBUG_CREDENTIALS
If unsure, say N. If unsure, say N.
#
# 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
help
config FRAME_POINTER
bool "Compile the kernel with frame pointers"
depends on DEBUG_KERNEL && \
(CRIS || M68K || FRV || UML || \
AVR32 || SUPERH || BLACKFIN || MN10300 || METAG) || \
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 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.
menu "RCU Debugging" menu "RCU Debugging"
config PROVE_RCU config PROVE_RCU
...@@ -1019,46 +1172,19 @@ config RCU_CPU_STALL_INFO ...@@ -1019,46 +1172,19 @@ config RCU_CPU_STALL_INFO
Say Y if you want to enable such diagnostics. Say Y if you want to enable such diagnostics.
config RCU_TRACE config RCU_TRACE
bool "Enable tracing for RCU" bool "Enable tracing for RCU"
depends on DEBUG_KERNEL
select TRACE_CLOCK
help
This option provides tracing in RCU which presents stats
in debugfs for debugging RCU implementation.
Say Y here if you want to enable RCU tracing
Say N if you are unsure.
endmenu # "RCU Debugging"
config KPROBES_SANITY_TEST
bool "Kprobes sanity tests"
depends on DEBUG_KERNEL
depends on KPROBES
default n
help
This option provides for testing basic kprobes functionality on
boot. A sample kprobe, jprobe 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 depends on DEBUG_KERNEL
default n select TRACE_CLOCK
help help
This option provides a kernel module that can be used to test This option provides tracing in RCU which presents stats
the kernel stack backtrace code. This option is not useful in debugfs for debugging RCU implementation.
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 Y here if you want to enable RCU tracing
Say N if you are unsure. Say N if you are unsure.
endmenu # "RCU Debugging"
config DEBUG_BLOCK_EXT_DEVT config DEBUG_BLOCK_EXT_DEVT
bool "Force extended block device numbers and spread them" bool "Force extended block device numbers and spread them"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
...@@ -1086,47 +1212,6 @@ config DEBUG_BLOCK_EXT_DEVT ...@@ -1086,47 +1212,6 @@ config DEBUG_BLOCK_EXT_DEVT
Say N if you are unsure. Say N if you are unsure.
config DEBUG_FORCE_WEAK_PER_CPU
bool "Force weak per-cpu definitions"
depends on DEBUG_KERNEL
help
s390 and alpha require percpu variables in modules to be
defined weak to work around addressing range issue which
puts the following two restrictions on percpu variable
definitions.
1. percpu symbols must be unique whether static or not
2. percpu variables can't be defined inside a function
To ensure that generic code follows the above rules, this
option forces all percpu variables to be defined as weak.
config 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 LKDTM
tristate "Linux Kernel Dump Test Tool Module"
depends on DEBUG_FS
depends on BLOCK
default n
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.txt
config NOTIFIER_ERROR_INJECTION config NOTIFIER_ERROR_INJECTION
tristate "Notifier error injection" tristate "Notifier error injection"
depends on DEBUG_KERNEL depends on DEBUG_KERNEL
...@@ -1186,29 +1271,6 @@ config PM_NOTIFIER_ERROR_INJECT ...@@ -1186,29 +1271,6 @@ config PM_NOTIFIER_ERROR_INJECT
If unsure, say N. If unsure, say N.
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 OF_RECONFIG_NOTIFIER_ERROR_INJECT config OF_RECONFIG_NOTIFIER_ERROR_INJECT
tristate "OF reconfig notifier error injection module" tristate "OF reconfig notifier error injection module"
depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION
...@@ -1323,9 +1385,61 @@ config DEBUG_STRICT_USER_COPY_CHECKS ...@@ -1323,9 +1385,61 @@ config DEBUG_STRICT_USER_COPY_CHECKS
If unsure, say N. If unsure, say N.
source mm/Kconfig.debug
source kernel/trace/Kconfig source kernel/trace/Kconfig
menu "Runtime Testing"
config LKDTM
tristate "Linux Kernel Dump Test Tool Module"
depends on DEBUG_FS
depends on BLOCK
default n
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.txt
config TEST_LIST_SORT
bool "Linked list sorting test"
depends on DEBUG_KERNEL
help
Enable this to turn on 'list_sort()' function test. This test is
executed only once during system boot, so affects only boot time.
If unsure, say N.
config KPROBES_SANITY_TEST
bool "Kprobes sanity tests"
depends on DEBUG_KERNEL
depends on KPROBES
default n
help
This option provides for testing basic kprobes functionality on
boot. A sample kprobe, jprobe 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
default n
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 config RBTREE_TEST
tristate "Red-Black tree test" tristate "Red-Black tree test"
depends on m && DEBUG_KERNEL depends on m && DEBUG_KERNEL
...@@ -1339,6 +1453,34 @@ config INTERVAL_TREE_TEST ...@@ -1339,6 +1453,34 @@ config INTERVAL_TREE_TEST
help help
A benchmark measuring the performance of the interval tree library A benchmark measuring the performance of the interval tree library
config ATOMIC64_SELFTEST
bool "Perform an atomic64_t self-test at boot"
help
Enable this option to test the atomic64_t functions at boot.
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_STRING_HELPERS
tristate "Test functions located in the string_helpers module at runtime"
config TEST_KSTRTOX
tristate "Test kstrto*() family of functions at runtime"
endmenu # runtime tests
config PROVIDE_OHCI1394_DMA_INIT config PROVIDE_OHCI1394_DMA_INIT
bool "Remote debugging over FireWire early on boot" bool "Remote debugging over FireWire early on boot"
depends on PCI && X86 depends on PCI && X86
...@@ -1388,75 +1530,6 @@ config BUILD_DOCSRC ...@@ -1388,75 +1530,6 @@ config BUILD_DOCSRC
Say N if you are unsure. Say N if you are unsure.
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/dynamic-debug-howto.txt for additional information.
config DMA_API_DEBUG config DMA_API_DEBUG
bool "Enable debugging of DMA-API usage" bool "Enable debugging of DMA-API usage"
depends on HAVE_DMA_API_DEBUG depends on HAVE_DMA_API_DEBUG
...@@ -1468,34 +1541,7 @@ config DMA_API_DEBUG ...@@ -1468,34 +1541,7 @@ config DMA_API_DEBUG
This option causes a performance degredation. Use only if you want This option causes a performance degredation. Use only if you want
to debug device drivers. If unsure, say N. to debug device drivers. If unsure, say N.
config ATOMIC64_SELFTEST
bool "Perform an atomic64_t self-test at boot"
help
Enable this option to test the atomic64_t functions at boot.
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.
source "samples/Kconfig" source "samples/Kconfig"
source "lib/Kconfig.kgdb" source "lib/Kconfig.kgdb"
source "lib/Kconfig.kmemcheck"
config TEST_STRING_HELPERS
tristate "Test functions located in the string_helpers module at runtime"
config TEST_KSTRTOX
tristate "Test kstrto*() family of functions at runtime"
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