From d1a1dc0be866219f7a613c6368c6a036b8eefe03 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 1 Jul 2013 13:04:42 -0700 Subject: consolidate per-arch stack overflow debugging options Original posting: http://lkml.kernel.org/r/20121214184202.F54094D9@kernel.stglabs.ibm.com Several architectures have similar stack debugging config options. They all pretty much do the same thing, some with slightly differing help text. This patch changes the architectures to instead enable a Kconfig boolean, and then use that boolean in the generic Kconfig.debug to present the actual menu option. This removes a bunch of duplication and adds consistency across arches. Signed-off-by: Dave Hansen Reviewed-by: H. Peter Anvin Reviewed-by: James Hogan Acked-by: Chris Metcalf [for tile] Signed-off-by: Dave Hansen Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 566cf2bc08ea..cc443bc6edfc 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1475,6 +1475,27 @@ config ASYNC_RAID6_TEST If unsure, say N. +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 "samples/Kconfig" source "lib/Kconfig.kgdb" -- cgit v1.2.3-58-ga151 From 0610c8a8a258e869a542e5fdb964c6816336559e Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 1 Jul 2013 13:04:43 -0700 Subject: order memory debugging Kconfig options Original posting: http://lkml.kernel.org/r/20121214184203.37E6C724@kernel.stglabs.ibm.com There are a *LOT* of memory debugging options. They are just scattered all over the "Kernel Hacking" menu. Sure, "memory debugging" is a very vague term and it's going to be hard to make absolute rules about what goes in here, but this has to be better than what we had before. This does, however, leave out the architecture-specific memory debugging options (like x86's DEBUG_SET_MODULE_RONX). There would need to be some substantial changes to move those in here. Kconfig can not easily mix arch-specific and generic options together: it really requires a file per-architecture, and I think having an arch/foo/Kconfig.debug-memory might be taking things a bit too far Signed-off-by: Dave Hansen Signed-off-by: Dave Hansen Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 685 +++++++++++++++++++++++++++--------------------------- 1 file changed, 345 insertions(+), 340 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index cc443bc6edfc..57e18ac6ca3c 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -162,6 +162,283 @@ config DEBUG_KERNEL Say Y here if you are developing drivers or trying to debug and identify kernel problems. +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 && !KMEMCHECK + 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 DEBUG_SLAB_LEAK + bool "Memory leak debugging" + depends on DEBUG_SLAB + +config SLUB_DEBUG_ON + bool "SLUB debugging on by default" + depends on SLUB && SLUB_DEBUG && !KMEMCHECK + 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/kmemleak.txt 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_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//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 @@ -266,241 +543,89 @@ config DETECT_HUNG_TASK 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 - 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 && !KMEMCHECK - 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. + 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. -config DEBUG_SLAB_LEAK - bool "Memory leak debugging" - depends on DEBUG_SLAB + 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 SLUB_DEBUG_ON - bool "SLUB debugging on by default" - depends on SLUB && SLUB_DEBUG && !KMEMCHECK - default n +config DEFAULT_HUNG_TASK_TIMEOUT + int "Default timeout for hung task detection (in seconds)" + depends on DETECT_HUNG_TASK + default 120 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=-". + This option controls the default timeout (in seconds) used + to determine when a task has become non-responsive and should + be considered hung. -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 + 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. -config HAVE_DEBUG_KMEMLEAK - bool + A timeout of 0 disables the check. The default is two minutes. + Keeping the default should be fine in most cases. -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 +config BOOTPARAM_HUNG_TASK_PANIC + bool "Panic (Reboot) On Hung Tasks" + depends on DETECT_HUNG_TASK 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/kmemleak.txt for more - details. + 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. - Enabling DEBUG_SLAB or SLUB_DEBUG may increase the chances - of finding leaks due to the slab objects poisoning. + 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. - In order to access the kmemleak file, debugfs needs to be - mounted (usually at /sys/kernel/debug). + Say N if unsure. -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 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 DEBUG_KMEMLEAK_TEST - tristate "Simple test for the kernel memory leak detector" - depends on DEBUG_KMEMLEAK && m +config SCHED_DEBUG + bool "Collect scheduler debugging info" + depends on DEBUG_KERNEL && PROC_FS + default y 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 - bool "Default kmemleak to off" - depends on DEBUG_KMEMLEAK +config TIMER_STATS + bool "Collect kernel timers statistics" + depends on DEBUG_KERNEL && PROC_FS help - Say Y here to disable kmemleak by default. It can then be enabled - on the command line via kmemleak=on. + 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_PREEMPT bool "Debug preemptible kernel" @@ -672,15 +797,6 @@ config STACKTRACE bool depends on STACKTRACE_SUPPORT -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_KOBJECT bool "kobject debugging" depends on DEBUG_KERNEL @@ -688,13 +804,6 @@ config DEBUG_KOBJECT If you say Y here, some extra kobject debugging messages will be sent 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 bool @@ -733,40 +842,6 @@ config DEBUG_INFO_REDUCED 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 bool "Debug filesystem writers count" depends on DEBUG_KERNEL @@ -777,18 +852,6 @@ config DEBUG_WRITECOUNT 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 bool "Debug linked list manipulation" depends on DEBUG_KERNEL @@ -1088,17 +1151,6 @@ config DEBUG_FORCE_WEAK_PER_CPU 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 @@ -1173,29 +1225,6 @@ config PM_NOTIFIER_ERROR_INJECT 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//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 tristate "OF reconfig notifier error injection module" depends on OF_DYNAMIC && NOTIFIER_ERROR_INJECTION @@ -1310,7 +1339,6 @@ config DEBUG_STRICT_USER_COPY_CHECKS If unsure, say N. -source mm/Kconfig.debug source kernel/trace/Kconfig config RBTREE_TEST @@ -1475,33 +1503,10 @@ config ASYNC_RAID6_TEST If unsure, say N. -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 "samples/Kconfig" source "lib/Kconfig.kgdb" -source "lib/Kconfig.kmemcheck" - config TEST_STRING_HELPERS tristate "Test functions located in the string_helpers module at runtime" -- cgit v1.2.3-58-ga151 From 881c5149543a3a391ab6ce2ebe70235924f15d9c Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 1 Jul 2013 13:04:44 -0700 Subject: consolidate runtime testing configs Original posting: http://lkml.kernel.org/r/20121214184206.FC11422F@kernel.stglabs.ibm.com These runtime tests are great, except that there are a lot of them, and they are very rarely needed. Give them their own menu so that only the folks who need them will have to go looking for them. Note that there are some other runtime tests that are not in here, like for RCU or locking. This menu should only be used for tests that do not have a more appropriate home. Signed-off-by: Dave Hansen Signed-off-by: Dave Hansen Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 157 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 81 insertions(+), 76 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 57e18ac6ca3c..6fdead79ee15 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -861,15 +861,6 @@ config DEBUG_LIST 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 bool "Debug SG table operations" depends on DEBUG_KERNEL @@ -1082,33 +1073,6 @@ config RCU_TRACE 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 - 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 DEBUG_BLOCK_EXT_DEVT bool "Force extended block device numbers and spread them" depends on DEBUG_KERNEL @@ -1151,21 +1115,6 @@ config DEBUG_FORCE_WEAK_PER_CPU To ensure that generic code follows the above rules, this option forces all percpu variables to be defined as weak. -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 tristate "Notifier error injection" depends on DEBUG_KERNEL @@ -1341,6 +1290,59 @@ config DEBUG_STRICT_USER_COPY_CHECKS 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 tristate "Red-Black tree test" depends on m && DEBUG_KERNEL @@ -1354,6 +1356,34 @@ config INTERVAL_TREE_TEST help 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 bool "Remote debugging over FireWire early on boot" depends on PCI && X86 @@ -1483,32 +1513,7 @@ config DMA_API_DEBUG This option causes a performance degredation. Use only if you want 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 "lib/Kconfig.kgdb" -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" -- cgit v1.2.3-58-ga151 From 6dfc06651b3d29aa07ed99b8075e5d324f7a953a Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 1 Jul 2013 13:04:46 -0700 Subject: consolidate compilation option configs Original Post: http://lkml.kernel.org/r/20121214184207.6E00DDEC@kernel.stglabs.ibm.com Again, trying to come up with some common themes of the stuff in the kernel hacking menu... There are quite a few options to tweak compilation in some way, or perform extra compile-time checks. Give them their own menu. The diff here looks a bit funny... makes it look like I'm moving debugfs even though I'm actually moving the options on either side of it. Signed-off-by: Dave Hansen Signed-off-by: Dave Hansen Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 156 ++++++++++++++++++++++++++++-------------------------- 1 file changed, 80 insertions(+), 76 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 6fdead79ee15..70dfda31c8aa 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -25,6 +25,34 @@ config DEFAULT_MESSAGE_LOGLEVEL that are auditing their logs closely may want to set it to a lower priority. +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 bool "Enable __deprecated logic" default y @@ -52,20 +80,6 @@ config FRAME_WARN Setting it to 0 disables the warning. 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 . Don't say Y - unless you really know what this hack does. - config STRIP_ASM_SYMS bool "Strip assembler-generated symbols during link" default n @@ -156,6 +170,58 @@ config DEBUG_SECTION_MISMATCH - Enable verbose reporting from modpost in order to help resolve the section mismatches that are reported. +# +# 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 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 . Don't say Y + unless you really know what this hack does. + config DEBUG_KERNEL bool "Kernel debugging" help @@ -816,32 +882,6 @@ config DEBUG_BUGVERBOSE of the BUG call as well as the EIP and oops trace. This aids 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_WRITECOUNT bool "Debug filesystem writers count" depends on DEBUG_KERNEL @@ -896,27 +936,6 @@ config DEBUG_CREDENTIALS 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 @@ -1100,21 +1119,6 @@ config DEBUG_BLOCK_EXT_DEVT 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 NOTIFIER_ERROR_INJECTION tristate "Notifier error injection" depends on DEBUG_KERNEL -- cgit v1.2.3-58-ga151 From 9eade16b4151ec35a9e03bbc7cc890e640a536c1 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 1 Jul 2013 13:04:47 -0700 Subject: group locking debugging options Original posting: http://lkml.kernel.org/r/20121214184208.D9E5804D@kernel.stglabs.ibm.com There are quite a few of these, and we want to make sure that there is one-stop-shopping for lock debugging. Signed-off-by: Dave Hansen Signed-off-by: Dave Hansen Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index 70dfda31c8aa..c0d41dfadc2d 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -703,6 +703,8 @@ config DEBUG_PREEMPT 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 DEBUG_RT_MUTEXES bool "RT Mutex debugging, deadlock detection" depends on DEBUG_KERNEL && RT_MUTEXES @@ -832,12 +834,6 @@ config DEBUG_LOCKDEP additional runtime checks to debug itself, at the price 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 bool "Sleep inside atomic section checking" select PREEMPT_COUNT @@ -859,6 +855,14 @@ config DEBUG_LOCKING_API_SELFTESTS The following locking APIs are covered: spinlocks, rwlocks, mutexes and rwsems. +endmenu # lock debugging + +config TRACE_IRQFLAGS + bool + help + Enables hooks to interrupt enabling and disabling for + either tracing or lock debugging. + config STACKTRACE bool depends on STACKTRACE_SUPPORT -- cgit v1.2.3-58-ga151 From 604ff0dceb2aca049a25a181c68f8db5c0798f7f Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 1 Jul 2013 13:04:49 -0700 Subject: kconfig: consolidate printk options Same deal, take the printk-related things and hide them in a menu. This takes another 4 items out of the top-level menu. Signed-off-by: Dave Hansen Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 177 +++++++++++++++++++++++++++--------------------------- 1 file changed, 90 insertions(+), 87 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index c0d41dfadc2d..a6c2c5c1a5f8 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -1,3 +1,4 @@ +menu "printk and dmesg options" config PRINTK_TIME bool "Show timing information on printks" @@ -25,6 +26,95 @@ config DEFAULT_MESSAGE_LOGLEVEL that are auditing their logs closely may want to set it to a lower 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: /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 /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' > + /dynamic_debug/control + + // enable all the messages in file svcsock.c + nullarbor:~ # echo -n 'file svcsock.c +p' > + /dynamic_debug/control + + // enable all the messages in the NFS server module + nullarbor:~ # echo -n 'module nfsd +p' > + /dynamic_debug/control + + // enable all 12 messages in the function svc_process() + nullarbor:~ # echo -n 'func svc_process +p' > + /dynamic_debug/control + + // disable all 12 messages in the function svc_process() + nullarbor:~ # echo -n 'func svc_process -p' > + /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 @@ -940,24 +1030,6 @@ config DEBUG_CREDENTIALS If unsure, say N. -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" config PROVE_RCU @@ -1441,75 +1513,6 @@ config BUILD_DOCSRC 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: /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 /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' > - /dynamic_debug/control - - // enable all the messages in file svcsock.c - nullarbor:~ # echo -n 'file svcsock.c +p' > - /dynamic_debug/control - - // enable all the messages in the NFS server module - nullarbor:~ # echo -n 'module nfsd +p' > - /dynamic_debug/control - - // enable all 12 messages in the function svc_process() - nullarbor:~ # echo -n 'func svc_process +p' > - /dynamic_debug/control - - // disable all 12 messages in the function svc_process() - nullarbor:~ # echo -n 'func svc_process -p' > - /dynamic_debug/control - - See Documentation/dynamic-debug-howto.txt for additional information. - config DMA_API_DEBUG bool "Enable debugging of DMA-API usage" depends on HAVE_DMA_API_DEBUG -- cgit v1.2.3-58-ga151 From 92aef8fbabb4cc8616777ab27d6499a3719c3e4c Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Mon, 1 Jul 2013 13:04:50 -0700 Subject: hang and lockup detection menu The hard/softlockup and hung-task entries take up 6 lines of screen real-estate when enabled. I bet folks don't mess with these _that_ often, so move them in a group down a level. Signed-off-by: Dave Hansen Signed-off-by: Linus Torvalds --- lib/Kconfig.debug | 42 +++++++++++++++++++++++------------------- 1 file changed, 23 insertions(+), 19 deletions(-) (limited to 'lib') diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index a6c2c5c1a5f8..65c8e4daee4a 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -604,6 +604,8 @@ config DEBUG_SHIRQ 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 @@ -675,25 +677,6 @@ config BOOTPARAM_SOFTLOCKUP_PANIC_VALUE default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC default 1 if BOOTPARAM_SOFTLOCKUP_PANIC -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 @@ -748,6 +731,27 @@ config BOOTPARAM_HUNG_TASK_PANIC_VALUE default 0 if !BOOTPARAM_HUNG_TASK_PANIC default 1 if BOOTPARAM_HUNG_TASK_PANIC +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 SCHED_DEBUG bool "Collect scheduler debugging info" depends on DEBUG_KERNEL && PROC_FS -- cgit v1.2.3-58-ga151