diff options
Diffstat (limited to 'lib/Kconfig.debug')
| -rw-r--r-- | lib/Kconfig.debug | 455 |
1 files changed, 239 insertions, 216 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index d03e2b1570ca..6859f523517b 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -128,8 +128,8 @@ config DYNAMIC_DEBUG 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 + flags : '=p' means the line is turned 'on' for printing + format : the format used for the debug statement From a live system: @@ -173,6 +173,15 @@ config SYMBOLIC_ERRNAME of the number 28. It makes the kernel image slightly larger (about 3KB), but can make the kernel logs easier to read. +config DEBUG_BUGVERBOSE + bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT + depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE) + default y + help + Say Y here to make BUG() panics output the file name and line number + of the BUG call as well as the EIP and oops trace. This aids + debugging but costs about 70-100K of memory. + endmenu # "printk and dmesg options" menu "Compile-time checks and compiler options" @@ -181,7 +190,7 @@ config DEBUG_INFO bool "Compile the kernel with debug info" depends on DEBUG_KERNEL && !COMPILE_TEST help - If you say Y here the resulting kernel image will include + 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 @@ -278,25 +287,13 @@ config STRIP_ASM_SYMS get_wchan() and suchlike. config READABLE_ASM - bool "Generate readable assembler code" - depends on DEBUG_KERNEL - help - Disable some compiler optimizations that tend to generate human unreadable - assembler output. This may make the kernel slightly slower, but it helps - to keep kernel developers who have to stare a lot at assembler listings - sane. - -config DEBUG_FS - bool "Debug Filesystem" + bool "Generate readable assembler code" + depends on DEBUG_KERNEL help - debugfs is a virtual file system that kernel developers use to put - debugging files into. Enable this option to be able to read and - write to these files. - - For detailed documentation on the debugfs API, see - Documentation/filesystems/. - - If unsure, say N. + Disable some compiler optimizations that tend to generate human unreadable + assembler output. This may make the kernel slightly slower, but it helps + to keep kernel developers who have to stare a lot at assembler listings + sane. config HEADERS_INSTALL bool "Install uapi headers to usr/include" @@ -399,6 +396,8 @@ config DEBUG_FORCE_WEAK_PER_CPU endmenu # "Compiler options" +menu "Generic Kernel Debugging Instruments" + config MAGIC_SYSRQ bool "Magic SysRq key" depends on !UML @@ -432,6 +431,24 @@ config MAGIC_SYSRQ_SERIAL This option allows you to decide whether you want to enable the magic SysRq key. +config DEBUG_FS + bool "Debug Filesystem" + help + debugfs is a virtual file system that kernel developers use to put + debugging files into. Enable this option to be able to read and + write to these files. + + For detailed documentation on the debugfs API, see + Documentation/filesystems/. + + If unsure, say N. + +source "lib/Kconfig.kgdb" + +source "lib/Kconfig.ubsan" + +endmenu + config DEBUG_KERNEL bool "Kernel debugging" help @@ -506,11 +523,11 @@ config DEBUG_OBJECTS_PERCPU_COUNTER 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 + range 0 1 + default "1" + depends on DEBUG_OBJECTS + help + Debug objects boot parameter default value config DEBUG_SLAB bool "Debug slab memory allocations" @@ -624,12 +641,24 @@ config DEBUG_STACK_USAGE This option will slow down process creation somewhat. +config SCHED_STACK_END_CHECK + bool "Detect stack corruption on calls to schedule()" + depends on DEBUG_KERNEL + default n + help + This option checks for a stack overrun on calls to schedule(). + If the stack end location is found to be over written always panic as + the content of the corrupted region can no longer be trusted. + This is to ensure no erroneous behaviour occurs which could result in + data corruption or a sporadic crash at a later stage once the region + is examined. The runtime overhead introduced is minimal. + config DEBUG_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. + that may impact performance. If unsure, say N. @@ -756,53 +785,6 @@ source "lib/Kconfig.kasan" endmenu # "Memory Debugging" -config ARCH_HAS_KCOV - bool - help - An architecture should select this when it can successfully - build and run with CONFIG_KCOV. This typically requires - disabling instrumentation for some early boot code. - -config CC_HAS_SANCOV_TRACE_PC - def_bool $(cc-option,-fsanitize-coverage=trace-pc) - -config KCOV - bool "Code coverage for fuzzing" - depends on ARCH_HAS_KCOV - depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS - select DEBUG_FS - select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC - help - KCOV exposes kernel code coverage information in a form suitable - for coverage-guided fuzzing (randomized testing). - - If RANDOMIZE_BASE is enabled, PC values will not be stable across - different machines and across reboots. If you need stable PC values, - disable RANDOMIZE_BASE. - - For more details, see Documentation/dev-tools/kcov.rst. - -config KCOV_ENABLE_COMPARISONS - bool "Enable comparison operands collection by KCOV" - depends on KCOV - depends on $(cc-option,-fsanitize-coverage=trace-cmp) - help - KCOV also exposes operands of every comparison in the instrumented - code along with operand sizes and PCs of the comparison instructions. - These operands can be used by fuzzing engines to improve the quality - of fuzzing coverage. - -config KCOV_INSTRUMENT_ALL - bool "Instrument all code by default" - depends on KCOV - default y - help - If you are doing generic system call fuzzing (like e.g. syzkaller), - then you will want to instrument the whole kernel and you should - say y here. If you are doing more targeted fuzzing (like e.g. - filesystem fuzzing with AFL) then you will want to enable coverage - for more specific subsets of files, and should say n here. - config DEBUG_SHIRQ bool "Debug shared IRQ handlers" depends on DEBUG_KERNEL @@ -812,7 +794,35 @@ 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" +menu "Debug Oops, Lockups and Hangs" + +config PANIC_ON_OOPS + bool "Panic on Oops" + help + Say Y here to enable the kernel to panic when it oopses. This + has the same effect as setting oops=panic on the kernel command + line. + + This feature is useful to ensure that the kernel does not do + anything erroneous after an oops which could result in data + corruption or other issues. + + Say N if unsure. + +config PANIC_ON_OOPS_VALUE + int + range 0 1 + default 0 if !PANIC_ON_OOPS + default 1 if PANIC_ON_OOPS + +config PANIC_TIMEOUT + int "panic timeout" + default 0 + help + Set the timeout value (in seconds) until a reboot occurs when the + the kernel panics. If n = 0, then we wait forever. A timeout + value n > 0 will wait n seconds before rebooting, while a timeout + value n < 0 will reboot immediately. config LOCKUP_DETECTOR bool @@ -970,33 +980,7 @@ config WQ_WATCHDOG endmenu # "Debug lockups and hangs" -config PANIC_ON_OOPS - bool "Panic on Oops" - help - Say Y here to enable the kernel to panic when it oopses. This - has the same effect as setting oops=panic on the kernel command - line. - - This feature is useful to ensure that the kernel does not do - anything erroneous after an oops which could result in data - corruption or other issues. - - Say N if unsure. - -config PANIC_ON_OOPS_VALUE - int - range 0 1 - default 0 if !PANIC_ON_OOPS - default 1 if PANIC_ON_OOPS - -config PANIC_TIMEOUT - int "panic timeout" - default 0 - help - Set the timeout value (in seconds) until a reboot occurs when the - the kernel panics. If n = 0, then we wait forever. A timeout - value n > 0 will wait n seconds before rebooting, while a timeout - value n < 0 will reboot immediately. +menu "Scheduler Debugging" config SCHED_DEBUG bool "Collect scheduler debugging info" @@ -1024,17 +1008,7 @@ config SCHEDSTATS application, you can say N to avoid the very slight overhead this adds. -config SCHED_STACK_END_CHECK - bool "Detect stack corruption on calls to schedule()" - depends on DEBUG_KERNEL - default n - help - This option checks for a stack overrun on calls to schedule(). - If the stack end location is found to be over written always panic as - the content of the corrupted region can no longer be trusted. - This is to ensure no erroneous behaviour occurs which could result in - data corruption or a sporadic crash at a later stage once the region - is examined. The runtime overhead introduced is minimal. +endmenu config DEBUG_TIMEKEEPING bool "Enable extra timekeeping sanity checking" @@ -1338,14 +1312,7 @@ config DEBUG_KOBJECT_RELEASE config HAVE_DEBUG_BUGVERBOSE bool -config DEBUG_BUGVERBOSE - bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT - depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE) - default y - help - Say Y here to make BUG() panics output the file name and line number - of the BUG call as well as the EIP and oops trace. This aids - debugging but costs about 70-100K of memory. +menu "Debug kernel data structures" config DEBUG_LIST bool "Debug linked list manipulation" @@ -1386,6 +1353,18 @@ config DEBUG_NOTIFIERS This is a relatively cheap check but if you care about maximum performance, say N. +config BUG_ON_DATA_CORRUPTION + bool "Trigger a BUG when data corruption is detected" + select DEBUG_LIST + help + Select this option if the kernel should BUG when it encounters + data corruption in kernel memory structures when they get checked + for validity. + + If unsure, say N. + +endmenu + config DEBUG_CREDENTIALS bool "Debug credential management" depends on DEBUG_KERNEL @@ -1419,7 +1398,7 @@ config DEBUG_WQ_FORCE_RR_CPU be impacted. 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 BLOCK default n @@ -1458,6 +1437,103 @@ config CPU_HOTPLUG_STATE_CONTROL Say N if your are unsure. +config LATENCYTOP + bool "Latency measuring infrastructure" + depends on DEBUG_KERNEL + depends on STACKTRACE_SUPPORT + depends on PROC_FS + select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 + select KALLSYMS + select KALLSYMS_ALL + select STACKTRACE + select SCHEDSTATS + select SCHED_DEBUG + help + Enable this option if you want to use the LatencyTOP tool + to find out which userspace is blocking on what kernel operations. + +source "kernel/trace/Kconfig" + +config PROVIDE_OHCI1394_DMA_INIT + bool "Remote debugging over FireWire early on boot" + depends on PCI && X86 + help + If you want to debug problems which hang or crash the kernel early + on boot and the crashing machine has a FireWire port, you can use + this feature to remotely access the memory of the crashed machine + over FireWire. This employs remote DMA as part of the OHCI1394 + specification which is now the standard for FireWire controllers. + + With remote DMA, you can monitor the printk buffer remotely using + firescope and access all memory below 4GB using fireproxy from gdb. + Even controlling a kernel debugger is possible using remote DMA. + + Usage: + + If ohci1394_dma=early is used as boot parameter, it will initialize + all OHCI1394 controllers which are found in the PCI config space. + + As all changes to the FireWire bus such as enabling and disabling + devices cause a bus reset and thereby disable remote DMA for all + devices, be sure to have the cable plugged and FireWire enabled on + the debugging host before booting the debug target for debugging. + + This code (~1k) is freed after boot. By then, the firewire stack + in charge of the OHCI-1394 controllers should be used instead. + + See Documentation/debugging-via-ohci1394.txt for more information. + +source "samples/Kconfig" + +config ARCH_HAS_DEVMEM_IS_ALLOWED + bool + +config STRICT_DEVMEM + bool "Filter access to /dev/mem" + depends on MMU && DEVMEM + depends on ARCH_HAS_DEVMEM_IS_ALLOWED + default y if PPC || X86 || ARM64 + help + If this option is disabled, you allow userspace (root) access to all + of memory, including kernel and userspace memory. Accidental + access to this is obviously disastrous, but specific access can + be used by people debugging the kernel. Note that with PAT support + enabled, even in this case there are restrictions on /dev/mem + use due to the cache aliasing requirements. + + If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem + file only allows userspace access to PCI space and the BIOS code and + data regions. This is sufficient for dosemu and X and all common + users of /dev/mem. + + If in doubt, say Y. + +config IO_STRICT_DEVMEM + bool "Filter I/O access to /dev/mem" + depends on STRICT_DEVMEM + help + If this option is disabled, you allow userspace (root) access to all + io-memory regardless of whether a driver is actively using that + range. Accidental access to this is obviously disastrous, but + specific access can be used by people debugging kernel drivers. + + If this option is switched on, the /dev/mem file only allows + userspace access to *idle* io-memory ranges (see /proc/iomem) This + may break traditional users of /dev/mem (dosemu, legacy X, etc...) + if the driver using a given range cannot be disabled. + + If in doubt, say Y. + +menu "$(SRCARCH) Debugging" + +source "arch/$(SRCARCH)/Kconfig.debug" + +endmenu + +menu "Kernel Testing and Coverage" + +source "lib/kunit/Kconfig" + config NOTIFIER_ERROR_INJECTION tristate "Notifier error injection" depends on DEBUG_KERNEL @@ -1616,53 +1692,53 @@ config FAULT_INJECTION_STACKTRACE_FILTER help Provide stacktrace filter for fault-injection capabilities -config LATENCYTOP - bool "Latency measuring infrastructure" - depends on DEBUG_KERNEL - depends on STACKTRACE_SUPPORT - depends on PROC_FS - select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86 - select KALLSYMS - select KALLSYMS_ALL - select STACKTRACE - select SCHEDSTATS - select SCHED_DEBUG - help - Enable this option if you want to use the LatencyTOP tool - to find out which userspace is blocking on what kernel operations. - -source "kernel/trace/Kconfig" - -config PROVIDE_OHCI1394_DMA_INIT - bool "Remote debugging over FireWire early on boot" - depends on PCI && X86 +config ARCH_HAS_KCOV + bool help - If you want to debug problems which hang or crash the kernel early - on boot and the crashing machine has a FireWire port, you can use - this feature to remotely access the memory of the crashed machine - over FireWire. This employs remote DMA as part of the OHCI1394 - specification which is now the standard for FireWire controllers. + An architecture should select this when it can successfully + build and run with CONFIG_KCOV. This typically requires + disabling instrumentation for some early boot code. - With remote DMA, you can monitor the printk buffer remotely using - firescope and access all memory below 4GB using fireproxy from gdb. - Even controlling a kernel debugger is possible using remote DMA. +config CC_HAS_SANCOV_TRACE_PC + def_bool $(cc-option,-fsanitize-coverage=trace-pc) - Usage: - If ohci1394_dma=early is used as boot parameter, it will initialize - all OHCI1394 controllers which are found in the PCI config space. +config KCOV + bool "Code coverage for fuzzing" + depends on ARCH_HAS_KCOV + depends on CC_HAS_SANCOV_TRACE_PC || GCC_PLUGINS + select DEBUG_FS + select GCC_PLUGIN_SANCOV if !CC_HAS_SANCOV_TRACE_PC + help + KCOV exposes kernel code coverage information in a form suitable + for coverage-guided fuzzing (randomized testing). - As all changes to the FireWire bus such as enabling and disabling - devices cause a bus reset and thereby disable remote DMA for all - devices, be sure to have the cable plugged and FireWire enabled on - the debugging host before booting the debug target for debugging. + If RANDOMIZE_BASE is enabled, PC values will not be stable across + different machines and across reboots. If you need stable PC values, + disable RANDOMIZE_BASE. - This code (~1k) is freed after boot. By then, the firewire stack - in charge of the OHCI-1394 controllers should be used instead. + For more details, see Documentation/dev-tools/kcov.rst. - See Documentation/debugging-via-ohci1394.txt for more information. +config KCOV_ENABLE_COMPARISONS + bool "Enable comparison operands collection by KCOV" + depends on KCOV + depends on $(cc-option,-fsanitize-coverage=trace-cmp) + help + KCOV also exposes operands of every comparison in the instrumented + code along with operand sizes and PCs of the comparison instructions. + These operands can be used by fuzzing engines to improve the quality + of fuzzing coverage. -source "lib/kunit/Kconfig" +config KCOV_INSTRUMENT_ALL + bool "Instrument all code by default" + depends on KCOV + default y + help + If you are doing generic system call fuzzing (like e.g. syzkaller), + then you will want to instrument the whole kernel and you should + say y here. If you are doing more targeted fuzzing (like e.g. + filesystem fuzzing with AFL) then you will want to enable coverage + for more specific subsets of files, and should say n here. menuconfig RUNTIME_TESTING_MENU bool "Runtime Testing" @@ -2099,62 +2175,7 @@ config MEMTEST memtest=17, mean do 17 test patterns. If you are unsure how to answer this question, answer N. -config BUG_ON_DATA_CORRUPTION - bool "Trigger a BUG when data corruption is detected" - select DEBUG_LIST - help - Select this option if the kernel should BUG when it encounters - data corruption in kernel memory structures when they get checked - for validity. - - If unsure, say N. - -source "samples/Kconfig" - -source "lib/Kconfig.kgdb" - -source "lib/Kconfig.ubsan" - -config ARCH_HAS_DEVMEM_IS_ALLOWED - bool -config STRICT_DEVMEM - bool "Filter access to /dev/mem" - depends on MMU && DEVMEM - depends on ARCH_HAS_DEVMEM_IS_ALLOWED - default y if PPC || X86 || ARM64 - ---help--- - If this option is disabled, you allow userspace (root) access to all - of memory, including kernel and userspace memory. Accidental - access to this is obviously disastrous, but specific access can - be used by people debugging the kernel. Note that with PAT support - enabled, even in this case there are restrictions on /dev/mem - use due to the cache aliasing requirements. - - If this option is switched on, and IO_STRICT_DEVMEM=n, the /dev/mem - file only allows userspace access to PCI space and the BIOS code and - data regions. This is sufficient for dosemu and X and all common - users of /dev/mem. - - If in doubt, say Y. - -config IO_STRICT_DEVMEM - bool "Filter I/O access to /dev/mem" - depends on STRICT_DEVMEM - ---help--- - If this option is disabled, you allow userspace (root) access to all - io-memory regardless of whether a driver is actively using that - range. Accidental access to this is obviously disastrous, but - specific access can be used by people debugging kernel drivers. - - If this option is switched on, the /dev/mem file only allows - userspace access to *idle* io-memory ranges (see /proc/iomem) This - may break traditional users of /dev/mem (dosemu, legacy X, etc...) - if the driver using a given range cannot be disabled. - - If in doubt, say Y. - -source "arch/$(SRCARCH)/Kconfig.debug" config HYPERV_TESTING bool "Microsoft Hyper-V driver testing" @@ -2163,4 +2184,6 @@ config HYPERV_TESTING help Select this option to enable Hyper-V vmbus testing. +endmenu # "Kernel Testing and Coverage" + endmenu # Kernel hacking |