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0ce20dd840
Patch series "KFENCE: A low-overhead sampling-based memory safety error detector", v7. This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a low-overhead sampling-based memory safety error detector of heap use-after-free, invalid-free, and out-of-bounds access errors. This series enables KFENCE for the x86 and arm64 architectures, and adds KFENCE hooks to the SLAB and SLUB allocators. KFENCE is designed to be enabled in production kernels, and has near zero performance overhead. Compared to KASAN, KFENCE trades performance for precision. The main motivation behind KFENCE's design, is that with enough total uptime KFENCE will detect bugs in code paths not typically exercised by non-production test workloads. One way to quickly achieve a large enough total uptime is when the tool is deployed across a large fleet of machines. KFENCE objects each reside on a dedicated page, at either the left or right page boundaries. The pages to the left and right of the object page are "guard pages", whose attributes are changed to a protected state, and cause page faults on any attempted access to them. Such page faults are then intercepted by KFENCE, which handles the fault gracefully by reporting a memory access error. Guarded allocations are set up based on a sample interval (can be set via kfence.sample_interval). After expiration of the sample interval, the next allocation through the main allocator (SLAB or SLUB) returns a guarded allocation from the KFENCE object pool. At this point, the timer is reset, and the next allocation is set up after the expiration of the interval. To enable/disable a KFENCE allocation through the main allocator's fast-path without overhead, KFENCE relies on static branches via the static keys infrastructure. The static branch is toggled to redirect the allocation to KFENCE. The KFENCE memory pool is of fixed size, and if the pool is exhausted no further KFENCE allocations occur. The default config is conservative with only 255 objects, resulting in a pool size of 2 MiB (with 4 KiB pages). We have verified by running synthetic benchmarks (sysbench I/O, hackbench) and production server-workload benchmarks that a kernel with KFENCE (using sample intervals 100-500ms) is performance-neutral compared to a non-KFENCE baseline kernel. KFENCE is inspired by GWP-ASan [1], a userspace tool with similar properties. The name "KFENCE" is a homage to the Electric Fence Malloc Debugger [2]. For more details, see Documentation/dev-tools/kfence.rst added in the series -- also viewable here: https://raw.githubusercontent.com/google/kasan/kfence/Documentation/dev-tools/kfence.rst [1] http://llvm.org/docs/GwpAsan.html [2] https://linux.die.net/man/3/efence This patch (of 9): This adds the Kernel Electric-Fence (KFENCE) infrastructure. KFENCE is a low-overhead sampling-based memory safety error detector of heap use-after-free, invalid-free, and out-of-bounds access errors. KFENCE is designed to be enabled in production kernels, and has near zero performance overhead. Compared to KASAN, KFENCE trades performance for precision. The main motivation behind KFENCE's design, is that with enough total uptime KFENCE will detect bugs in code paths not typically exercised by non-production test workloads. One way to quickly achieve a large enough total uptime is when the tool is deployed across a large fleet of machines. KFENCE objects each reside on a dedicated page, at either the left or right page boundaries. The pages to the left and right of the object page are "guard pages", whose attributes are changed to a protected state, and cause page faults on any attempted access to them. Such page faults are then intercepted by KFENCE, which handles the fault gracefully by reporting a memory access error. To detect out-of-bounds writes to memory within the object's page itself, KFENCE also uses pattern-based redzones. The following figure illustrates the page layout: ---+-----------+-----------+-----------+-----------+-----------+--- | xxxxxxxxx | O : | xxxxxxxxx | : O | xxxxxxxxx | | xxxxxxxxx | B : | xxxxxxxxx | : B | xxxxxxxxx | | x GUARD x | J : RED- | x GUARD x | RED- : J | x GUARD x | | xxxxxxxxx | E : ZONE | xxxxxxxxx | ZONE : E | xxxxxxxxx | | xxxxxxxxx | C : | xxxxxxxxx | : C | xxxxxxxxx | | xxxxxxxxx | T : | xxxxxxxxx | : T | xxxxxxxxx | ---+-----------+-----------+-----------+-----------+-----------+--- Guarded allocations are set up based on a sample interval (can be set via kfence.sample_interval). After expiration of the sample interval, a guarded allocation from the KFENCE object pool is returned to the main allocator (SLAB or SLUB). At this point, the timer is reset, and the next allocation is set up after the expiration of the interval. To enable/disable a KFENCE allocation through the main allocator's fast-path without overhead, KFENCE relies on static branches via the static keys infrastructure. The static branch is toggled to redirect the allocation to KFENCE. To date, we have verified by running synthetic benchmarks (sysbench I/O, hackbench) that a kernel compiled with KFENCE is performance-neutral compared to the non-KFENCE baseline. For more details, see Documentation/dev-tools/kfence.rst (added later in the series). [elver@google.com: fix parameter description for kfence_object_start()] Link: https://lkml.kernel.org/r/20201106092149.GA2851373@elver.google.com [elver@google.com: avoid stalling work queue task without allocations] Link: https://lkml.kernel.org/r/CADYN=9J0DQhizAGB0-jz4HOBBh+05kMBXb4c0cXMS7Qi5NAJiw@mail.gmail.com Link: https://lkml.kernel.org/r/20201110135320.3309507-1-elver@google.com [elver@google.com: fix potential deadlock due to wake_up()] Link: https://lkml.kernel.org/r/000000000000c0645805b7f982e4@google.com Link: https://lkml.kernel.org/r/20210104130749.1768991-1-elver@google.com [elver@google.com: add option to use KFENCE without static keys] Link: https://lkml.kernel.org/r/20210111091544.3287013-1-elver@google.com [elver@google.com: add missing copyright and description headers] Link: https://lkml.kernel.org/r/20210118092159.145934-1-elver@google.com Link: https://lkml.kernel.org/r/20201103175841.3495947-2-elver@google.com Signed-off-by: Marco Elver <elver@google.com> Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: SeongJae Park <sjpark@amazon.de> Co-developed-by: Marco Elver <elver@google.com> Reviewed-by: Jann Horn <jannh@google.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Paul E. McKenney <paulmck@kernel.org> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christopher Lameter <cl@linux.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Hillf Danton <hdanton@sina.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Joern Engel <joern@purestorage.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2543 lines
83 KiB
Plaintext
2543 lines
83 KiB
Plaintext
# SPDX-License-Identifier: GPL-2.0-only
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menu "Kernel hacking"
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menu "printk and dmesg options"
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config PRINTK_TIME
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bool "Show timing information on printks"
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depends on PRINTK
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help
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Selecting this option causes time stamps of the printk()
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messages to be added to the output of the syslog() system
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call and at the console.
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The timestamp is always recorded internally, and exported
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to /dev/kmsg. This flag just specifies if the timestamp should
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be included, not that the timestamp is recorded.
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The behavior is also controlled by the kernel command line
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parameter printk.time=1. See Documentation/admin-guide/kernel-parameters.rst
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config PRINTK_CALLER
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bool "Show caller information on printks"
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depends on PRINTK
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help
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Selecting this option causes printk() to add a caller "thread id" (if
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in task context) or a caller "processor id" (if not in task context)
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to every message.
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This option is intended for environments where multiple threads
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concurrently call printk() for many times, for it is difficult to
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interpret without knowing where these lines (or sometimes individual
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line which was divided into multiple lines due to race) came from.
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Since toggling after boot makes the code racy, currently there is
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no option to enable/disable at the kernel command line parameter or
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sysfs interface.
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config CONSOLE_LOGLEVEL_DEFAULT
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int "Default console loglevel (1-15)"
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range 1 15
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default "7"
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help
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Default loglevel to determine what will be printed on the console.
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Setting a default here is equivalent to passing in loglevel=<x> in
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the kernel bootargs. loglevel=<x> continues to override whatever
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value is specified here as well.
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Note: This does not affect the log level of un-prefixed printk()
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usage in the kernel. That is controlled by the MESSAGE_LOGLEVEL_DEFAULT
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option.
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config CONSOLE_LOGLEVEL_QUIET
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int "quiet console loglevel (1-15)"
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range 1 15
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default "4"
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help
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loglevel to use when "quiet" is passed on the kernel commandline.
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When "quiet" is passed on the kernel commandline this loglevel
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will be used as the loglevel. IOW passing "quiet" will be the
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equivalent of passing "loglevel=<CONSOLE_LOGLEVEL_QUIET>"
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config MESSAGE_LOGLEVEL_DEFAULT
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int "Default message log level (1-7)"
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range 1 7
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default "4"
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help
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Default log level for printk statements with no specified priority.
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This was hard-coded to KERN_WARNING since at least 2.6.10 but folks
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that are auditing their logs closely may want to set it to a lower
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priority.
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Note: This does not affect what message level gets printed on the console
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by default. To change that, use loglevel=<x> in the kernel bootargs,
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or pick a different CONSOLE_LOGLEVEL_DEFAULT configuration value.
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config BOOT_PRINTK_DELAY
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bool "Delay each boot printk message by N milliseconds"
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depends on DEBUG_KERNEL && PRINTK && GENERIC_CALIBRATE_DELAY
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help
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This build option allows you to read kernel boot messages
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by inserting a short delay after each one. The delay is
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specified in milliseconds on the kernel command line,
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using "boot_delay=N".
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It is likely that you would also need to use "lpj=M" to preset
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the "loops per jiffie" value.
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See a previous boot log for the "lpj" value to use for your
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system, and then set "lpj=M" before setting "boot_delay=N".
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NOTE: Using this option may adversely affect SMP systems.
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I.e., processors other than the first one may not boot up.
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BOOT_PRINTK_DELAY also may cause LOCKUP_DETECTOR to detect
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what it believes to be lockup conditions.
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config DYNAMIC_DEBUG
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bool "Enable dynamic printk() support"
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default n
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depends on PRINTK
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depends on (DEBUG_FS || PROC_FS)
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select DYNAMIC_DEBUG_CORE
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help
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Compiles debug level messages into the kernel, which would not
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otherwise be available at runtime. These messages can then be
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enabled/disabled based on various levels of scope - per source file,
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function, module, format string, and line number. This mechanism
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implicitly compiles in all pr_debug() and dev_dbg() calls, which
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enlarges the kernel text size by about 2%.
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If a source file is compiled with DEBUG flag set, any
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pr_debug() calls in it are enabled by default, but can be
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disabled at runtime as below. Note that DEBUG flag is
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turned on by many CONFIG_*DEBUG* options.
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Usage:
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Dynamic debugging is controlled via the 'dynamic_debug/control' file,
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which is contained in the 'debugfs' filesystem or procfs.
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Thus, the debugfs or procfs filesystem must first be mounted before
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making use of this feature.
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We refer the control file as: <debugfs>/dynamic_debug/control. This
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file contains a list of the debug statements that can be enabled. The
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format for each line of the file is:
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filename:lineno [module]function flags format
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filename : source file of the debug statement
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lineno : line number of the debug statement
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module : module that contains the debug statement
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function : function that contains the debug statement
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flags : '=p' means the line is turned 'on' for printing
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format : the format used for the debug statement
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From a live system:
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nullarbor:~ # cat <debugfs>/dynamic_debug/control
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# filename:lineno [module]function flags format
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fs/aio.c:222 [aio]__put_ioctx =_ "__put_ioctx:\040freeing\040%p\012"
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fs/aio.c:248 [aio]ioctx_alloc =_ "ENOMEM:\040nr_events\040too\040high\012"
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fs/aio.c:1770 [aio]sys_io_cancel =_ "calling\040cancel\012"
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Example usage:
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// enable the message at line 1603 of file svcsock.c
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nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' >
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<debugfs>/dynamic_debug/control
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// enable all the messages in file svcsock.c
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nullarbor:~ # echo -n 'file svcsock.c +p' >
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<debugfs>/dynamic_debug/control
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// enable all the messages in the NFS server module
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nullarbor:~ # echo -n 'module nfsd +p' >
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<debugfs>/dynamic_debug/control
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// enable all 12 messages in the function svc_process()
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nullarbor:~ # echo -n 'func svc_process +p' >
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<debugfs>/dynamic_debug/control
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// disable all 12 messages in the function svc_process()
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nullarbor:~ # echo -n 'func svc_process -p' >
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<debugfs>/dynamic_debug/control
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See Documentation/admin-guide/dynamic-debug-howto.rst for additional
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information.
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config DYNAMIC_DEBUG_CORE
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bool "Enable core function of dynamic debug support"
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depends on PRINTK
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depends on (DEBUG_FS || PROC_FS)
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help
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Enable core functional support of dynamic debug. It is useful
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when you want to tie dynamic debug to your kernel modules with
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DYNAMIC_DEBUG_MODULE defined for each of them, especially for
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the case of embedded system where the kernel image size is
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sensitive for people.
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config SYMBOLIC_ERRNAME
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bool "Support symbolic error names in printf"
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default y if PRINTK
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help
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If you say Y here, the kernel's printf implementation will
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be able to print symbolic error names such as ENOSPC instead
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of the number 28. It makes the kernel image slightly larger
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(about 3KB), but can make the kernel logs easier to read.
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config DEBUG_BUGVERBOSE
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bool "Verbose BUG() reporting (adds 70K)" if DEBUG_KERNEL && EXPERT
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depends on BUG && (GENERIC_BUG || HAVE_DEBUG_BUGVERBOSE)
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default y
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help
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Say Y here to make BUG() panics output the file name and line number
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of the BUG call as well as the EIP and oops trace. This aids
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debugging but costs about 70-100K of memory.
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endmenu # "printk and dmesg options"
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menu "Compile-time checks and compiler options"
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config DEBUG_INFO
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bool "Compile the kernel with debug info"
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depends on DEBUG_KERNEL && !COMPILE_TEST
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help
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If you say Y here the resulting kernel image will include
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debugging info resulting in a larger kernel image.
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This adds debug symbols to the kernel and modules (gcc -g), and
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is needed if you intend to use kernel crashdump or binary object
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tools like crash, kgdb, LKCD, gdb, etc on the kernel.
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Say Y here only if you plan to debug the kernel.
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If unsure, say N.
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if DEBUG_INFO
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config DEBUG_INFO_REDUCED
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bool "Reduce debugging information"
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help
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If you say Y here gcc is instructed to generate less debugging
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information for structure types. This means that tools that
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need full debugging information (like kgdb or systemtap) won't
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be happy. But if you merely need debugging information to
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resolve line numbers there is no loss. Advantage is that
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build directory object sizes shrink dramatically over a full
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DEBUG_INFO build and compile times are reduced too.
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Only works with newer gcc versions.
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config DEBUG_INFO_COMPRESSED
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bool "Compressed debugging information"
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depends on $(cc-option,-gz=zlib)
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depends on $(ld-option,--compress-debug-sections=zlib)
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help
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Compress the debug information using zlib. Requires GCC 5.0+ or Clang
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5.0+, binutils 2.26+, and zlib.
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Users of dpkg-deb via scripts/package/builddeb may find an increase in
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size of their debug .deb packages with this config set, due to the
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debug info being compressed with zlib, then the object files being
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recompressed with a different compression scheme. But this is still
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preferable to setting $KDEB_COMPRESS to "none" which would be even
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larger.
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config DEBUG_INFO_SPLIT
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bool "Produce split debuginfo in .dwo files"
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depends on $(cc-option,-gsplit-dwarf)
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help
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Generate debug info into separate .dwo files. This significantly
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reduces the build directory size for builds with DEBUG_INFO,
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because it stores the information only once on disk in .dwo
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files instead of multiple times in object files and executables.
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In addition the debug information is also compressed.
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Requires recent gcc (4.7+) and recent gdb/binutils.
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Any tool that packages or reads debug information would need
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to know about the .dwo files and include them.
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Incompatible with older versions of ccache.
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choice
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prompt "DWARF version"
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help
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Which version of DWARF debug info to emit.
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config DEBUG_INFO_DWARF_TOOLCHAIN_DEFAULT
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bool "Rely on the toolchain's implicit default DWARF version"
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help
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The implicit default version of DWARF debug info produced by a
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toolchain changes over time.
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This can break consumers of the debug info that haven't upgraded to
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support newer revisions, and prevent testing newer versions, but
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those should be less common scenarios.
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If unsure, say Y.
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config DEBUG_INFO_DWARF4
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bool "Generate DWARF Version 4 debuginfo"
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help
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Generate DWARF v4 debug info. This requires gcc 4.5+ and gdb 7.0+.
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If you have consumers of DWARF debug info that are not ready for
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newer revisions of DWARF, you may wish to choose this or have your
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config select this.
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config DEBUG_INFO_DWARF5
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bool "Generate DWARF Version 5 debuginfo"
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depends on GCC_VERSION >= 50000 || CC_IS_CLANG
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depends on CC_IS_GCC || $(success,$(srctree)/scripts/test_dwarf5_support.sh $(CC) $(CLANG_FLAGS))
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depends on !DEBUG_INFO_BTF
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help
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Generate DWARF v5 debug info. Requires binutils 2.35.2, gcc 5.0+ (gcc
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5.0+ accepts the -gdwarf-5 flag but only had partial support for some
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draft features until 7.0), and gdb 8.0+.
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Changes to the structure of debug info in Version 5 allow for around
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15-18% savings in resulting image and debug info section sizes as
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compared to DWARF Version 4. DWARF Version 5 standardizes previous
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extensions such as accelerators for symbol indexing and the format
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for fission (.dwo/.dwp) files. Users may not want to select this
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config if they rely on tooling that has not yet been updated to
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support DWARF Version 5.
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endchoice # "DWARF version"
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config DEBUG_INFO_BTF
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bool "Generate BTF typeinfo"
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depends on !DEBUG_INFO_SPLIT && !DEBUG_INFO_REDUCED
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depends on !GCC_PLUGIN_RANDSTRUCT || COMPILE_TEST
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help
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Generate deduplicated BTF type information from DWARF debug info.
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Turning this on expects presence of pahole tool, which will convert
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DWARF type info into equivalent deduplicated BTF type info.
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config PAHOLE_HAS_SPLIT_BTF
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def_bool $(success, test `$(PAHOLE) --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/'` -ge "119")
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config DEBUG_INFO_BTF_MODULES
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def_bool y
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depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
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help
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Generate compact split BTF type information for kernel modules.
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config GDB_SCRIPTS
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bool "Provide GDB scripts for kernel debugging"
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help
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This creates the required links to GDB helper scripts in the
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build directory. If you load vmlinux into gdb, the helper
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scripts will be automatically imported by gdb as well, and
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additional functions are available to analyze a Linux kernel
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instance. See Documentation/dev-tools/gdb-kernel-debugging.rst
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for further details.
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endif # DEBUG_INFO
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config FRAME_WARN
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int "Warn for stack frames larger than"
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range 0 8192
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default 2048 if GCC_PLUGIN_LATENT_ENTROPY
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default 1280 if (!64BIT && PARISC)
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default 1024 if (!64BIT && !PARISC)
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default 2048 if 64BIT
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help
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Tell gcc to warn at build time for stack frames larger than this.
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Setting this too low will cause a lot of warnings.
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Setting it to 0 disables the warning.
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config STRIP_ASM_SYMS
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bool "Strip assembler-generated symbols during link"
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default n
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help
|
|
Strip internal assembler-generated symbols during a link (symbols
|
|
that look like '.Lxxx') so they don't pollute the output of
|
|
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 HEADERS_INSTALL
|
|
bool "Install uapi headers to usr/include"
|
|
depends on !UML
|
|
help
|
|
This option will install uapi headers (headers exported to user-space)
|
|
into the usr/include directory for use during the kernel build.
|
|
This is unneeded for building the kernel itself, but needed for some
|
|
user-space program samples. It is also needed by some features such
|
|
as uapi header sanity checks.
|
|
|
|
config DEBUG_SECTION_MISMATCH
|
|
bool "Enable full Section mismatch analysis"
|
|
help
|
|
The section mismatch analysis checks if there are illegal
|
|
references from one section to another section.
|
|
During linktime or runtime, some sections are dropped;
|
|
any use of code/data previously in these sections would
|
|
most likely result in an oops.
|
|
In the code, functions and variables are annotated with
|
|
__init,, etc. (see the full list in include/linux/init.h),
|
|
which results in the code/data being placed in specific sections.
|
|
The section mismatch analysis is always performed after a full
|
|
kernel build, and enabling this option causes the following
|
|
additional step to occur:
|
|
- Add the option -fno-inline-functions-called-once to gcc commands.
|
|
When inlining a function annotated with __init in a non-init
|
|
function, we would lose the section information and thus
|
|
the analysis would not catch the illegal reference.
|
|
This option tells gcc to inline less (but it does result in
|
|
a larger kernel).
|
|
|
|
config SECTION_MISMATCH_WARN_ONLY
|
|
bool "Make section mismatch errors non-fatal"
|
|
default y
|
|
help
|
|
If you say N here, the build process will fail if there are any
|
|
section mismatch, instead of just throwing warnings.
|
|
|
|
If unsure, say Y.
|
|
|
|
config DEBUG_FORCE_FUNCTION_ALIGN_32B
|
|
bool "Force all function address 32B aligned" if EXPERT
|
|
help
|
|
There are cases that a commit from one domain changes the function
|
|
address alignment of other domains, and cause magic performance
|
|
bump (regression or improvement). Enable this option will help to
|
|
verify if the bump is caused by function alignment changes, while
|
|
it will slightly increase the kernel size and affect icache usage.
|
|
|
|
It is mainly for debug and performance tuning use.
|
|
|
|
#
|
|
# 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
|
|
|
|
config FRAME_POINTER
|
|
bool "Compile the kernel with frame pointers"
|
|
depends on DEBUG_KERNEL && (M68K || UML || SUPERH) || 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 STACK_VALIDATION
|
|
bool "Compile-time stack metadata validation"
|
|
depends on HAVE_STACK_VALIDATION
|
|
default n
|
|
help
|
|
Add compile-time checks to validate stack metadata, including frame
|
|
pointers (if CONFIG_FRAME_POINTER is enabled). This helps ensure
|
|
that runtime stack traces are more reliable.
|
|
|
|
This is also a prerequisite for generation of ORC unwind data, which
|
|
is needed for CONFIG_UNWINDER_ORC.
|
|
|
|
For more information, see
|
|
tools/objtool/Documentation/stack-validation.txt.
|
|
|
|
config VMLINUX_VALIDATION
|
|
bool
|
|
depends on STACK_VALIDATION && DEBUG_ENTRY && !PARAVIRT
|
|
default y
|
|
|
|
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"
|
|
|
|
menu "Generic Kernel Debugging Instruments"
|
|
|
|
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/admin-guide/sysrq.rst>.
|
|
Don't say Y unless you really know what this hack does.
|
|
|
|
config MAGIC_SYSRQ_DEFAULT_ENABLE
|
|
hex "Enable magic SysRq key functions by default"
|
|
depends on MAGIC_SYSRQ
|
|
default 0x1
|
|
help
|
|
Specifies which SysRq key functions are enabled by default.
|
|
This may be set to 1 or 0 to enable or disable them all, or
|
|
to a bitmask as described in Documentation/admin-guide/sysrq.rst.
|
|
|
|
config MAGIC_SYSRQ_SERIAL
|
|
bool "Enable magic SysRq key over serial"
|
|
depends on MAGIC_SYSRQ
|
|
default y
|
|
help
|
|
Many embedded boards have a disconnected TTL level serial which can
|
|
generate some garbage that can lead to spurious false sysrq detects.
|
|
This option allows you to decide whether you want to enable the
|
|
magic SysRq key.
|
|
|
|
config MAGIC_SYSRQ_SERIAL_SEQUENCE
|
|
string "Char sequence that enables magic SysRq over serial"
|
|
depends on MAGIC_SYSRQ_SERIAL
|
|
default ""
|
|
help
|
|
Specifies a sequence of characters that can follow BREAK to enable
|
|
SysRq on a serial console.
|
|
|
|
If unsure, leave an empty string and the option will not be enabled.
|
|
|
|
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.
|
|
|
|
choice
|
|
prompt "Debugfs default access"
|
|
depends on DEBUG_FS
|
|
default DEBUG_FS_ALLOW_ALL
|
|
help
|
|
This selects the default access restrictions for debugfs.
|
|
It can be overridden with kernel command line option
|
|
debugfs=[on,no-mount,off]. The restrictions apply for API access
|
|
and filesystem registration.
|
|
|
|
config DEBUG_FS_ALLOW_ALL
|
|
bool "Access normal"
|
|
help
|
|
No restrictions apply. Both API and filesystem registration
|
|
is on. This is the normal default operation.
|
|
|
|
config DEBUG_FS_DISALLOW_MOUNT
|
|
bool "Do not register debugfs as filesystem"
|
|
help
|
|
The API is open but filesystem is not loaded. Clients can still do
|
|
their work and read with debug tools that do not need
|
|
debugfs filesystem.
|
|
|
|
config DEBUG_FS_ALLOW_NONE
|
|
bool "No access"
|
|
help
|
|
Access is off. Clients get -PERM when trying to create nodes in
|
|
debugfs tree and debugfs is not registered as a filesystem.
|
|
Client can then back-off or continue without debugfs access.
|
|
|
|
endchoice
|
|
|
|
source "lib/Kconfig.kgdb"
|
|
source "lib/Kconfig.ubsan"
|
|
source "lib/Kconfig.kcsan"
|
|
|
|
endmenu
|
|
|
|
config DEBUG_KERNEL
|
|
bool "Kernel debugging"
|
|
help
|
|
Say Y here if you are developing drivers or trying to debug and
|
|
identify kernel problems.
|
|
|
|
config DEBUG_MISC
|
|
bool "Miscellaneous debug code"
|
|
default DEBUG_KERNEL
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Say Y here if you need to enable miscellaneous debug code that should
|
|
be under a more specific debug option but isn't.
|
|
|
|
|
|
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
|
|
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 SLUB_DEBUG_ON
|
|
bool "SLUB debugging on by default"
|
|
depends on SLUB && SLUB_DEBUG
|
|
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/dev-tools/kmemleak.rst 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_MEM_POOL_SIZE
|
|
int "Kmemleak memory pool size"
|
|
depends on DEBUG_KMEMLEAK
|
|
range 200 1000000
|
|
default 16000
|
|
help
|
|
Kmemleak must track all the memory allocations to avoid
|
|
reporting false positives. Since memory may be allocated or
|
|
freed before kmemleak is fully initialised, use a static pool
|
|
of metadata objects to track such callbacks. After kmemleak is
|
|
fully initialised, this memory pool acts as an emergency one
|
|
if slab allocations fail.
|
|
|
|
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_KMEMLEAK_AUTO_SCAN
|
|
bool "Enable kmemleak auto scan thread on boot up"
|
|
default y
|
|
depends on DEBUG_KMEMLEAK
|
|
help
|
|
Depending on the cpu, kmemleak scan may be cpu intensive and can
|
|
stall user tasks at times. This option enables/disables automatic
|
|
kmemleak scan at boot up.
|
|
|
|
Say N here to disable kmemleak auto scan thread to stop automatic
|
|
scanning. Disabling this option disables automatic reporting of
|
|
memory leaks.
|
|
|
|
If unsure, say Y.
|
|
|
|
config DEBUG_STACK_USAGE
|
|
bool "Stack utilization instrumentation"
|
|
depends on DEBUG_KERNEL && !IA64
|
|
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 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 ARCH_HAS_DEBUG_VM_PGTABLE
|
|
bool
|
|
help
|
|
An architecture should select this when it can successfully
|
|
build and run DEBUG_VM_PGTABLE.
|
|
|
|
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_VMACACHE
|
|
bool "Debug VMA caching"
|
|
depends on DEBUG_VM
|
|
help
|
|
Enable this to turn on VMA caching debug information. Doing so
|
|
can cause significant overhead, so only enable it in non-production
|
|
environments.
|
|
|
|
If unsure, say N.
|
|
|
|
config DEBUG_VM_RB
|
|
bool "Debug VM red-black trees"
|
|
depends on DEBUG_VM
|
|
help
|
|
Enable VM red-black tree debugging information and extra validations.
|
|
|
|
If unsure, say N.
|
|
|
|
config DEBUG_VM_PGFLAGS
|
|
bool "Debug page-flags operations"
|
|
depends on DEBUG_VM
|
|
help
|
|
Enables extra validation on page flags operations.
|
|
|
|
If unsure, say N.
|
|
|
|
config DEBUG_VM_PGTABLE
|
|
bool "Debug arch page table for semantics compliance"
|
|
depends on MMU
|
|
depends on ARCH_HAS_DEBUG_VM_PGTABLE
|
|
default y if DEBUG_VM
|
|
help
|
|
This option provides a debug method which can be used to test
|
|
architecture page table helper functions on various platforms in
|
|
verifying if they comply with expected generic MM semantics. This
|
|
will help architecture code in making sure that any changes or
|
|
new additions of these helpers still conform to expected
|
|
semantics of the generic MM. Platforms will have to opt in for
|
|
this through ARCH_HAS_DEBUG_VM_PGTABLE.
|
|
|
|
If unsure, say N.
|
|
|
|
config ARCH_HAS_DEBUG_VIRTUAL
|
|
bool
|
|
|
|
config DEBUG_VIRTUAL
|
|
bool "Debug VM translations"
|
|
depends on DEBUG_KERNEL && ARCH_HAS_DEBUG_VIRTUAL
|
|
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_KMAP_LOCAL
|
|
bool "Debug kmap_local temporary mappings"
|
|
depends on DEBUG_KERNEL && KMAP_LOCAL
|
|
help
|
|
This option enables additional error checking for the kmap_local
|
|
infrastructure. Disable for production use.
|
|
|
|
config ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
|
|
bool
|
|
|
|
config DEBUG_KMAP_LOCAL_FORCE_MAP
|
|
bool "Enforce kmap_local temporary mappings"
|
|
depends on DEBUG_KERNEL && ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
|
|
select KMAP_LOCAL
|
|
select DEBUG_KMAP_LOCAL
|
|
help
|
|
This option enforces temporary mappings through the kmap_local
|
|
mechanism for non-highmem pages and on non-highmem systems.
|
|
Disable this for production systems!
|
|
|
|
config DEBUG_HIGHMEM
|
|
bool "Highmem debugging"
|
|
depends on DEBUG_KERNEL && HIGHMEM
|
|
select DEBUG_KMAP_LOCAL_FORCE_MAP if ARCH_SUPPORTS_KMAP_LOCAL_FORCE_MAP
|
|
select DEBUG_KMAP_LOCAL
|
|
help
|
|
This option enables additional 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 architecture 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.kasan"
|
|
source "lib/Kconfig.kfence"
|
|
|
|
endmenu # "Memory Debugging"
|
|
|
|
config DEBUG_SHIRQ
|
|
bool "Debug shared IRQ handlers"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Enable this to generate a spurious interrupt just before a shared
|
|
interrupt handler is deregistered (generating one when registering
|
|
is currently disabled). Drivers need to handle this correctly. Some
|
|
don't and need to be caught.
|
|
|
|
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 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
|
|
|
|
config SOFTLOCKUP_DETECTOR
|
|
bool "Detect Soft Lockups"
|
|
depends on DEBUG_KERNEL && !S390
|
|
select LOCKUP_DETECTOR
|
|
help
|
|
Say Y here to enable the kernel to act as a watchdog to detect
|
|
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.
|
|
|
|
config BOOTPARAM_SOFTLOCKUP_PANIC
|
|
bool "Panic (Reboot) On Soft Lockups"
|
|
depends on SOFTLOCKUP_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 SOFTLOCKUP_DETECTOR
|
|
range 0 1
|
|
default 0 if !BOOTPARAM_SOFTLOCKUP_PANIC
|
|
default 1 if BOOTPARAM_SOFTLOCKUP_PANIC
|
|
|
|
config HARDLOCKUP_DETECTOR_PERF
|
|
bool
|
|
select SOFTLOCKUP_DETECTOR
|
|
|
|
#
|
|
# Enables a timestamp based low pass filter to compensate for perf based
|
|
# hard lockup detection which runs too fast due to turbo modes.
|
|
#
|
|
config HARDLOCKUP_CHECK_TIMESTAMP
|
|
bool
|
|
|
|
#
|
|
# arch/ can define HAVE_HARDLOCKUP_DETECTOR_ARCH to provide their own hard
|
|
# lockup detector rather than the perf based detector.
|
|
#
|
|
config HARDLOCKUP_DETECTOR
|
|
bool "Detect Hard Lockups"
|
|
depends on DEBUG_KERNEL && !S390
|
|
depends on HAVE_HARDLOCKUP_DETECTOR_PERF || HAVE_HARDLOCKUP_DETECTOR_ARCH
|
|
select LOCKUP_DETECTOR
|
|
select HARDLOCKUP_DETECTOR_PERF if HAVE_HARDLOCKUP_DETECTOR_PERF
|
|
select HARDLOCKUP_DETECTOR_ARCH if HAVE_HARDLOCKUP_DETECTOR_ARCH
|
|
help
|
|
Say Y here to enable the kernel to act as a watchdog to detect
|
|
hard lockups.
|
|
|
|
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.
|
|
|
|
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 DETECT_HUNG_TASK
|
|
bool "Detect Hung Tasks"
|
|
depends on DEBUG_KERNEL
|
|
default SOFTLOCKUP_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 indefinitely.
|
|
|
|
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 WQ_WATCHDOG
|
|
bool "Detect Workqueue Stalls"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Say Y here to enable stall detection on workqueues. If a
|
|
worker pool doesn't make forward progress on a pending work
|
|
item for over a given amount of time, 30s by default, a
|
|
warning message is printed along with dump of workqueue
|
|
state. This can be configured through kernel parameter
|
|
"workqueue.watchdog_thresh" and its sysfs counterpart.
|
|
|
|
config TEST_LOCKUP
|
|
tristate "Test module to generate lockups"
|
|
depends on m
|
|
help
|
|
This builds the "test_lockup" module that helps to make sure
|
|
that watchdogs and lockup detectors are working properly.
|
|
|
|
Depending on module parameters it could emulate soft or hard
|
|
lockup, "hung task", or locking arbitrary lock for a long time.
|
|
Also it could generate series of lockups with cooling-down periods.
|
|
|
|
If unsure, say N.
|
|
|
|
endmenu # "Debug lockups and hangs"
|
|
|
|
menu "Scheduler Debugging"
|
|
|
|
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 SCHED_INFO
|
|
bool
|
|
default n
|
|
|
|
config SCHEDSTATS
|
|
bool "Collect scheduler statistics"
|
|
depends on DEBUG_KERNEL && PROC_FS
|
|
select SCHED_INFO
|
|
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.
|
|
|
|
endmenu
|
|
|
|
config DEBUG_TIMEKEEPING
|
|
bool "Enable extra timekeeping sanity checking"
|
|
help
|
|
This option will enable additional timekeeping sanity checks
|
|
which may be helpful when diagnosing issues where timekeeping
|
|
problems are suspected.
|
|
|
|
This may include checks in the timekeeping hotpaths, so this
|
|
option may have a (very small) performance impact to some
|
|
workloads.
|
|
|
|
If unsure, say N.
|
|
|
|
config DEBUG_PREEMPT
|
|
bool "Debug preemptible kernel"
|
|
depends on DEBUG_KERNEL && PREEMPTION && TRACE_IRQFLAGS_SUPPORT
|
|
default y
|
|
help
|
|
If you say Y here then the kernel will use a debug variant of the
|
|
commonly used smp_processor_id() function and will print warnings
|
|
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 LOCK_DEBUGGING_SUPPORT
|
|
bool
|
|
depends on TRACE_IRQFLAGS_SUPPORT && STACKTRACE_SUPPORT && LOCKDEP_SUPPORT
|
|
default y
|
|
|
|
config PROVE_LOCKING
|
|
bool "Lock debugging: prove locking correctness"
|
|
depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
|
|
select LOCKDEP
|
|
select DEBUG_SPINLOCK
|
|
select DEBUG_MUTEXES
|
|
select DEBUG_RT_MUTEXES if RT_MUTEXES
|
|
select DEBUG_RWSEMS
|
|
select DEBUG_WW_MUTEX_SLOWPATH
|
|
select DEBUG_LOCK_ALLOC
|
|
select PREEMPT_COUNT if !ARCH_NO_PREEMPT
|
|
select TRACE_IRQFLAGS
|
|
default n
|
|
help
|
|
This feature enables the kernel to prove that all locking
|
|
that occurs in the kernel runtime is mathematically
|
|
correct: that under no circumstance could an arbitrary (and
|
|
not yet triggered) combination of observed locking
|
|
sequences (on an arbitrary number of CPUs, running an
|
|
arbitrary number of tasks and interrupt contexts) cause a
|
|
deadlock.
|
|
|
|
In short, this feature enables the kernel to report locking
|
|
related deadlocks before they actually occur.
|
|
|
|
The proof does not depend on how hard and complex a
|
|
deadlock scenario would be to trigger: how many
|
|
participant CPUs, tasks and irq-contexts would be needed
|
|
for it to trigger. The proof also does not depend on
|
|
timing: if a race and a resulting deadlock is possible
|
|
theoretically (no matter how unlikely the race scenario
|
|
is), it will be proven so and will immediately be
|
|
reported by the kernel (once the event is observed that
|
|
makes the deadlock theoretically possible).
|
|
|
|
If a deadlock is impossible (i.e. the locking rules, as
|
|
observed by the kernel, are mathematically correct), the
|
|
kernel reports nothing.
|
|
|
|
NOTE: this feature can also be enabled for rwlocks, mutexes
|
|
and rwsems - in which case all dependencies between these
|
|
different locking variants are observed and mapped too, and
|
|
the proof of observed correctness is also maintained for an
|
|
arbitrary combination of these separate locking variants.
|
|
|
|
For more details, see Documentation/locking/lockdep-design.rst.
|
|
|
|
config PROVE_RAW_LOCK_NESTING
|
|
bool "Enable raw_spinlock - spinlock nesting checks"
|
|
depends on PROVE_LOCKING
|
|
default n
|
|
help
|
|
Enable the raw_spinlock vs. spinlock nesting checks which ensure
|
|
that the lock nesting rules for PREEMPT_RT enabled kernels are
|
|
not violated.
|
|
|
|
NOTE: There are known nesting problems. So if you enable this
|
|
option expect lockdep splats until these problems have been fully
|
|
addressed which is work in progress. This config switch allows to
|
|
identify and analyze these problems. It will be removed and the
|
|
check permanentely enabled once the main issues have been fixed.
|
|
|
|
If unsure, select N.
|
|
|
|
config LOCK_STAT
|
|
bool "Lock usage statistics"
|
|
depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
|
|
select LOCKDEP
|
|
select DEBUG_SPINLOCK
|
|
select DEBUG_MUTEXES
|
|
select DEBUG_RT_MUTEXES if RT_MUTEXES
|
|
select DEBUG_LOCK_ALLOC
|
|
default n
|
|
help
|
|
This feature enables tracking lock contention points
|
|
|
|
For more details, see Documentation/locking/lockstat.rst
|
|
|
|
This also enables lock events required by "perf lock",
|
|
subcommand of perf.
|
|
If you want to use "perf lock", you also need to turn on
|
|
CONFIG_EVENT_TRACING.
|
|
|
|
CONFIG_LOCK_STAT defines "contended" and "acquired" lock events.
|
|
(CONFIG_LOCKDEP defines "acquire" and "release" events.)
|
|
|
|
config DEBUG_RT_MUTEXES
|
|
bool "RT Mutex debugging, deadlock detection"
|
|
depends on DEBUG_KERNEL && RT_MUTEXES
|
|
help
|
|
This allows rt mutex semantics violations and rt mutex related
|
|
deadlocks (lockups) to be detected and reported automatically.
|
|
|
|
config DEBUG_SPINLOCK
|
|
bool "Spinlock and rw-lock debugging: basic checks"
|
|
depends on DEBUG_KERNEL
|
|
select UNINLINE_SPIN_UNLOCK
|
|
help
|
|
Say Y here and build SMP to catch missing spinlock initialization
|
|
and certain other kinds of spinlock errors commonly made. This is
|
|
best used in conjunction with the NMI watchdog so that spinlock
|
|
deadlocks are also debuggable.
|
|
|
|
config DEBUG_MUTEXES
|
|
bool "Mutex debugging: basic checks"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
This feature allows mutex semantics violations to be detected and
|
|
reported.
|
|
|
|
config DEBUG_WW_MUTEX_SLOWPATH
|
|
bool "Wait/wound mutex debugging: Slowpath testing"
|
|
depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
|
|
select DEBUG_LOCK_ALLOC
|
|
select DEBUG_SPINLOCK
|
|
select DEBUG_MUTEXES
|
|
help
|
|
This feature enables slowpath testing for w/w mutex users by
|
|
injecting additional -EDEADLK wound/backoff cases. Together with
|
|
the full mutex checks enabled with (CONFIG_PROVE_LOCKING) this
|
|
will test all possible w/w mutex interface abuse with the
|
|
exception of simply not acquiring all the required locks.
|
|
Note that this feature can introduce significant overhead, so
|
|
it really should not be enabled in a production or distro kernel,
|
|
even a debug kernel. If you are a driver writer, enable it. If
|
|
you are a distro, do not.
|
|
|
|
config DEBUG_RWSEMS
|
|
bool "RW Semaphore debugging: basic checks"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
This debugging feature allows mismatched rw semaphore locks
|
|
and unlocks to be detected and reported.
|
|
|
|
config DEBUG_LOCK_ALLOC
|
|
bool "Lock debugging: detect incorrect freeing of live locks"
|
|
depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
|
|
select DEBUG_SPINLOCK
|
|
select DEBUG_MUTEXES
|
|
select DEBUG_RT_MUTEXES if RT_MUTEXES
|
|
select LOCKDEP
|
|
help
|
|
This feature will check whether any held lock (spinlock, rwlock,
|
|
mutex or rwsem) is incorrectly freed by the kernel, via any of the
|
|
memory-freeing routines (kfree(), kmem_cache_free(), free_pages(),
|
|
vfree(), etc.), whether a live lock is incorrectly reinitialized via
|
|
spin_lock_init()/mutex_init()/etc., or whether there is any lock
|
|
held during task exit.
|
|
|
|
config LOCKDEP
|
|
bool
|
|
depends on DEBUG_KERNEL && LOCK_DEBUGGING_SUPPORT
|
|
select STACKTRACE
|
|
select FRAME_POINTER if !MIPS && !PPC && !ARM && !S390 && !MICROBLAZE && !ARC && !X86
|
|
select KALLSYMS
|
|
select KALLSYMS_ALL
|
|
|
|
config LOCKDEP_SMALL
|
|
bool
|
|
|
|
config DEBUG_LOCKDEP
|
|
bool "Lock dependency engine debugging"
|
|
depends on DEBUG_KERNEL && LOCKDEP
|
|
select DEBUG_IRQFLAGS
|
|
help
|
|
If you say Y here, the lock dependency engine will do
|
|
additional runtime checks to debug itself, at the price
|
|
of more runtime overhead.
|
|
|
|
config DEBUG_ATOMIC_SLEEP
|
|
bool "Sleep inside atomic section checking"
|
|
select PREEMPT_COUNT
|
|
depends on DEBUG_KERNEL
|
|
depends on !ARCH_NO_PREEMPT
|
|
help
|
|
If you say Y here, various routines which may sleep will become very
|
|
noisy if they are called inside atomic sections: when a spinlock is
|
|
held, inside an rcu read side critical section, inside preempt disabled
|
|
sections, inside an interrupt, etc...
|
|
|
|
config DEBUG_LOCKING_API_SELFTESTS
|
|
bool "Locking API boot-time self-tests"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Say Y here if you want the kernel to run a short self-test during
|
|
bootup. The self-test checks whether common types of locking bugs
|
|
are detected by debugging mechanisms or not. (if you disable
|
|
lock debugging then those bugs wont be detected of course.)
|
|
The following locking APIs are covered: spinlocks, rwlocks,
|
|
mutexes and rwsems.
|
|
|
|
config LOCK_TORTURE_TEST
|
|
tristate "torture tests for locking"
|
|
depends on DEBUG_KERNEL
|
|
select TORTURE_TEST
|
|
help
|
|
This option provides a kernel module that runs torture tests
|
|
on kernel locking primitives. The kernel module may be built
|
|
after the fact on the running kernel to be tested, if desired.
|
|
|
|
Say Y here if you want kernel locking-primitive torture tests
|
|
to be built into the kernel.
|
|
Say M if you want these torture tests to build as a module.
|
|
Say N if you are unsure.
|
|
|
|
config WW_MUTEX_SELFTEST
|
|
tristate "Wait/wound mutex selftests"
|
|
help
|
|
This option provides a kernel module that runs tests on the
|
|
on the struct ww_mutex locking API.
|
|
|
|
It is recommended to enable DEBUG_WW_MUTEX_SLOWPATH in conjunction
|
|
with this test harness.
|
|
|
|
Say M if you want these self tests to build as a module.
|
|
Say N if you are unsure.
|
|
|
|
config SCF_TORTURE_TEST
|
|
tristate "torture tests for smp_call_function*()"
|
|
depends on DEBUG_KERNEL
|
|
select TORTURE_TEST
|
|
help
|
|
This option provides a kernel module that runs torture tests
|
|
on the smp_call_function() family of primitives. The kernel
|
|
module may be built after the fact on the running kernel to
|
|
be tested, if desired.
|
|
|
|
config CSD_LOCK_WAIT_DEBUG
|
|
bool "Debugging for csd_lock_wait(), called from smp_call_function*()"
|
|
depends on DEBUG_KERNEL
|
|
depends on 64BIT
|
|
default n
|
|
help
|
|
This option enables debug prints when CPUs are slow to respond
|
|
to the smp_call_function*() IPI wrappers. These debug prints
|
|
include the IPI handler function currently executing (if any)
|
|
and relevant stack traces.
|
|
|
|
endmenu # lock debugging
|
|
|
|
config TRACE_IRQFLAGS
|
|
depends on TRACE_IRQFLAGS_SUPPORT
|
|
bool
|
|
help
|
|
Enables hooks to interrupt enabling and disabling for
|
|
either tracing or lock debugging.
|
|
|
|
config TRACE_IRQFLAGS_NMI
|
|
def_bool y
|
|
depends on TRACE_IRQFLAGS
|
|
depends on TRACE_IRQFLAGS_NMI_SUPPORT
|
|
|
|
config DEBUG_IRQFLAGS
|
|
bool "Debug IRQ flag manipulation"
|
|
help
|
|
Enables checks for potentially unsafe enabling or disabling of
|
|
interrupts, such as calling raw_local_irq_restore() when interrupts
|
|
are enabled.
|
|
|
|
config STACKTRACE
|
|
bool "Stack backtrace support"
|
|
depends on STACKTRACE_SUPPORT
|
|
help
|
|
This option causes the kernel to create a /proc/pid/stack for
|
|
every process, showing its current stack trace.
|
|
It is also used by various kernel debugging features that require
|
|
stack trace generation.
|
|
|
|
config WARN_ALL_UNSEEDED_RANDOM
|
|
bool "Warn for all uses of unseeded randomness"
|
|
default n
|
|
help
|
|
Some parts of the kernel contain bugs relating to their use of
|
|
cryptographically secure random numbers before it's actually possible
|
|
to generate those numbers securely. This setting ensures that these
|
|
flaws don't go unnoticed, by enabling a message, should this ever
|
|
occur. This will allow people with obscure setups to know when things
|
|
are going wrong, so that they might contact developers about fixing
|
|
it.
|
|
|
|
Unfortunately, on some models of some architectures getting
|
|
a fully seeded CRNG is extremely difficult, and so this can
|
|
result in dmesg getting spammed for a surprisingly long
|
|
time. This is really bad from a security perspective, and
|
|
so architecture maintainers really need to do what they can
|
|
to get the CRNG seeded sooner after the system is booted.
|
|
However, since users cannot do anything actionable to
|
|
address this, by default the kernel will issue only a single
|
|
warning for the first use of unseeded randomness.
|
|
|
|
Say Y here if you want to receive warnings for all uses of
|
|
unseeded randomness. This will be of use primarily for
|
|
those developers interested in improving the security of
|
|
Linux kernels running on their architecture (or
|
|
subarchitecture).
|
|
|
|
config DEBUG_KOBJECT
|
|
bool "kobject debugging"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
If you say Y here, some extra kobject debugging messages will be sent
|
|
to the syslog.
|
|
|
|
config DEBUG_KOBJECT_RELEASE
|
|
bool "kobject release debugging"
|
|
depends on DEBUG_OBJECTS_TIMERS
|
|
help
|
|
kobjects are reference counted objects. This means that their
|
|
last reference count put is not predictable, and the kobject can
|
|
live on past the point at which a driver decides to drop it's
|
|
initial reference to the kobject gained on allocation. An
|
|
example of this would be a struct device which has just been
|
|
unregistered.
|
|
|
|
However, some buggy drivers assume that after such an operation,
|
|
the memory backing the kobject can be immediately freed. This
|
|
goes completely against the principles of a refcounted object.
|
|
|
|
If you say Y here, the kernel will delay the release of kobjects
|
|
on the last reference count to improve the visibility of this
|
|
kind of kobject release bug.
|
|
|
|
config HAVE_DEBUG_BUGVERBOSE
|
|
bool
|
|
|
|
menu "Debug kernel data structures"
|
|
|
|
config DEBUG_LIST
|
|
bool "Debug linked list manipulation"
|
|
depends on DEBUG_KERNEL || BUG_ON_DATA_CORRUPTION
|
|
help
|
|
Enable this to turn on extended checks in the linked-list
|
|
walking routines.
|
|
|
|
If unsure, say N.
|
|
|
|
config DEBUG_PLIST
|
|
bool "Debug priority linked list manipulation"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Enable this to turn on extended checks in the priority-ordered
|
|
linked-list (plist) walking routines. This checks the entire
|
|
list multiple times during each manipulation.
|
|
|
|
If unsure, say N.
|
|
|
|
config DEBUG_SG
|
|
bool "Debug SG table operations"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Enable this to turn on checks on scatter-gather tables. This can
|
|
help find problems with drivers that do not properly initialize
|
|
their sg tables.
|
|
|
|
If unsure, say N.
|
|
|
|
config DEBUG_NOTIFIERS
|
|
bool "Debug notifier call chains"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Enable this to turn on sanity checking for notifier call chains.
|
|
This is most useful for kernel developers to make sure that
|
|
modules properly unregister themselves from notifier chains.
|
|
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
|
|
help
|
|
Enable this to turn on some debug checking for credential
|
|
management. The additional code keeps track of the number of
|
|
pointers from task_structs to any given cred struct, and checks to
|
|
see that this number never exceeds the usage count of the cred
|
|
struct.
|
|
|
|
Furthermore, if SELinux is enabled, this also checks that the
|
|
security pointer in the cred struct is never seen to be invalid.
|
|
|
|
If unsure, say N.
|
|
|
|
source "kernel/rcu/Kconfig.debug"
|
|
|
|
config DEBUG_WQ_FORCE_RR_CPU
|
|
bool "Force round-robin CPU selection for unbound work items"
|
|
depends on DEBUG_KERNEL
|
|
default n
|
|
help
|
|
Workqueue used to implicitly guarantee that work items queued
|
|
without explicit CPU specified are put on the local CPU. This
|
|
guarantee is no longer true and while local CPU is still
|
|
preferred work items may be put on foreign CPUs. Kernel
|
|
parameter "workqueue.debug_force_rr_cpu" is added to force
|
|
round-robin CPU selection to flush out usages which depend on the
|
|
now broken guarantee. This config option enables the debug
|
|
feature by default. When enabled, memory and cache locality will
|
|
be impacted.
|
|
|
|
config DEBUG_BLOCK_EXT_DEVT
|
|
bool "Force extended block device numbers and spread them"
|
|
depends on DEBUG_KERNEL
|
|
depends on BLOCK
|
|
default n
|
|
help
|
|
BIG FAT WARNING: ENABLING THIS OPTION MIGHT BREAK BOOTING ON
|
|
SOME DISTRIBUTIONS. DO NOT ENABLE THIS UNLESS YOU KNOW WHAT
|
|
YOU ARE DOING. Distros, please enable this and fix whatever
|
|
is broken.
|
|
|
|
Conventionally, block device numbers are allocated from
|
|
predetermined contiguous area. However, extended block area
|
|
may introduce non-contiguous block device numbers. This
|
|
option forces most block device numbers to be allocated from
|
|
the extended space and spreads them to discover kernel or
|
|
userland code paths which assume predetermined contiguous
|
|
device number allocation.
|
|
|
|
Note that turning on this debug option shuffles all the
|
|
device numbers for all IDE and SCSI devices including libata
|
|
ones, so root partition specified using device number
|
|
directly (via rdev or root=MAJ:MIN) won't work anymore.
|
|
Textual device names (root=/dev/sdXn) will continue to work.
|
|
|
|
Say N if you are unsure.
|
|
|
|
config CPU_HOTPLUG_STATE_CONTROL
|
|
bool "Enable CPU hotplug state control"
|
|
depends on DEBUG_KERNEL
|
|
depends on HOTPLUG_CPU
|
|
default n
|
|
help
|
|
Allows to write steps between "offline" and "online" to the CPUs
|
|
sysfs target file so states can be stepped granular. This is a debug
|
|
option for now as the hotplug machinery cannot be stopped and
|
|
restarted at arbitrary points yet.
|
|
|
|
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/core-api/debugging-via-ohci1394.rst 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 || GENERIC_LIB_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
|
|
select DEBUG_FS
|
|
help
|
|
This option provides the ability to inject artificial errors to
|
|
specified notifier chain callbacks. It is useful to test the error
|
|
handling of notifier call chain failures.
|
|
|
|
Say N if unsure.
|
|
|
|
config PM_NOTIFIER_ERROR_INJECT
|
|
tristate "PM notifier error injection module"
|
|
depends on PM && NOTIFIER_ERROR_INJECTION
|
|
default m if PM_DEBUG
|
|
help
|
|
This option provides the ability to inject artificial errors to
|
|
PM notifier chain callbacks. It is controlled through debugfs
|
|
interface /sys/kernel/debug/notifier-error-inject/pm
|
|
|
|
If the notifier call chain should be failed with some events
|
|
notified, write the error code to "actions/<notifier event>/error".
|
|
|
|
Example: Inject PM suspend error (-12 = -ENOMEM)
|
|
|
|
# cd /sys/kernel/debug/notifier-error-inject/pm/
|
|
# echo -12 > actions/PM_SUSPEND_PREPARE/error
|
|
# echo mem > /sys/power/state
|
|
bash: echo: write error: Cannot allocate memory
|
|
|
|
To compile this code as a module, choose M here: the module will
|
|
be called pm-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
|
|
help
|
|
This option provides the ability to inject artificial errors to
|
|
OF reconfig notifier chain callbacks. It is controlled
|
|
through debugfs interface under
|
|
/sys/kernel/debug/notifier-error-inject/OF-reconfig/
|
|
|
|
If the notifier call chain should be failed with some events
|
|
notified, write the error code to "actions/<notifier event>/error".
|
|
|
|
To compile this code as a module, choose M here: the module will
|
|
be called of-reconfig-notifier-error-inject.
|
|
|
|
If unsure, say N.
|
|
|
|
config NETDEV_NOTIFIER_ERROR_INJECT
|
|
tristate "Netdev notifier error injection module"
|
|
depends on NET && NOTIFIER_ERROR_INJECTION
|
|
help
|
|
This option provides the ability to inject artificial errors to
|
|
netdevice notifier chain callbacks. It is controlled through debugfs
|
|
interface /sys/kernel/debug/notifier-error-inject/netdev
|
|
|
|
If the notifier call chain should be failed with some events
|
|
notified, write the error code to "actions/<notifier event>/error".
|
|
|
|
Example: Inject netdevice mtu change error (-22 = -EINVAL)
|
|
|
|
# cd /sys/kernel/debug/notifier-error-inject/netdev
|
|
# echo -22 > actions/NETDEV_CHANGEMTU/error
|
|
# ip link set eth0 mtu 1024
|
|
RTNETLINK answers: Invalid argument
|
|
|
|
To compile this code as a module, choose M here: the module will
|
|
be called netdev-notifier-error-inject.
|
|
|
|
If unsure, say N.
|
|
|
|
config FUNCTION_ERROR_INJECTION
|
|
def_bool y
|
|
depends on HAVE_FUNCTION_ERROR_INJECTION && KPROBES
|
|
|
|
config FAULT_INJECTION
|
|
bool "Fault-injection framework"
|
|
depends on DEBUG_KERNEL
|
|
help
|
|
Provide fault-injection framework.
|
|
For more details, see Documentation/fault-injection/.
|
|
|
|
config FAILSLAB
|
|
bool "Fault-injection capability for kmalloc"
|
|
depends on FAULT_INJECTION
|
|
depends on SLAB || SLUB
|
|
help
|
|
Provide fault-injection capability for kmalloc.
|
|
|
|
config FAIL_PAGE_ALLOC
|
|
bool "Fault-injection capability for alloc_pages()"
|
|
depends on FAULT_INJECTION
|
|
help
|
|
Provide fault-injection capability for alloc_pages().
|
|
|
|
config FAULT_INJECTION_USERCOPY
|
|
bool "Fault injection capability for usercopy functions"
|
|
depends on FAULT_INJECTION
|
|
help
|
|
Provides fault-injection capability to inject failures
|
|
in usercopy functions (copy_from_user(), get_user(), ...).
|
|
|
|
config FAIL_MAKE_REQUEST
|
|
bool "Fault-injection capability for disk IO"
|
|
depends on FAULT_INJECTION && BLOCK
|
|
help
|
|
Provide fault-injection capability for disk IO.
|
|
|
|
config FAIL_IO_TIMEOUT
|
|
bool "Fault-injection capability for faking disk interrupts"
|
|
depends on FAULT_INJECTION && BLOCK
|
|
help
|
|
Provide fault-injection capability on end IO handling. This
|
|
will make the block layer "forget" an interrupt as configured,
|
|
thus exercising the error handling.
|
|
|
|
Only works with drivers that use the generic timeout handling,
|
|
for others it wont do anything.
|
|
|
|
config FAIL_FUTEX
|
|
bool "Fault-injection capability for futexes"
|
|
select DEBUG_FS
|
|
depends on FAULT_INJECTION && FUTEX
|
|
help
|
|
Provide fault-injection capability for futexes.
|
|
|
|
config FAULT_INJECTION_DEBUG_FS
|
|
bool "Debugfs entries for fault-injection capabilities"
|
|
depends on FAULT_INJECTION && SYSFS && DEBUG_FS
|
|
help
|
|
Enable configuration of fault-injection capabilities via debugfs.
|
|
|
|
config FAIL_FUNCTION
|
|
bool "Fault-injection capability for functions"
|
|
depends on FAULT_INJECTION_DEBUG_FS && FUNCTION_ERROR_INJECTION
|
|
help
|
|
Provide function-based fault-injection capability.
|
|
This will allow you to override a specific function with a return
|
|
with given return value. As a result, function caller will see
|
|
an error value and have to handle it. This is useful to test the
|
|
error handling in various subsystems.
|
|
|
|
config FAIL_MMC_REQUEST
|
|
bool "Fault-injection capability for MMC IO"
|
|
depends on FAULT_INJECTION_DEBUG_FS && MMC
|
|
help
|
|
Provide fault-injection capability for MMC IO.
|
|
This will make the mmc core return data errors. This is
|
|
useful to test the error handling in the mmc block device
|
|
and to test how the mmc host driver handles retries from
|
|
the block device.
|
|
|
|
config FAULT_INJECTION_STACKTRACE_FILTER
|
|
bool "stacktrace filter for fault-injection capabilities"
|
|
depends on FAULT_INJECTION_DEBUG_FS && STACKTRACE_SUPPORT
|
|
depends on !X86_64
|
|
select STACKTRACE
|
|
select FRAME_POINTER if !MIPS && !PPC && !S390 && !MICROBLAZE && !ARM && !ARC && !X86
|
|
help
|
|
Provide stacktrace filter for fault-injection capabilities
|
|
|
|
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 KCOV_IRQ_AREA_SIZE
|
|
hex "Size of interrupt coverage collection area in words"
|
|
depends on KCOV
|
|
default 0x40000
|
|
help
|
|
KCOV uses preallocated per-cpu areas to collect coverage from
|
|
soft interrupts. This specifies the size of those areas in the
|
|
number of unsigned long words.
|
|
|
|
menuconfig RUNTIME_TESTING_MENU
|
|
bool "Runtime Testing"
|
|
def_bool y
|
|
|
|
if RUNTIME_TESTING_MENU
|
|
|
|
config LKDTM
|
|
tristate "Linux Kernel Dump Test Tool Module"
|
|
depends on DEBUG_FS
|
|
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.rst
|
|
|
|
config TEST_LIST_SORT
|
|
tristate "Linked list sorting test"
|
|
depends on DEBUG_KERNEL || m
|
|
help
|
|
Enable this to turn on 'list_sort()' function test. This test is
|
|
executed only once during system boot (so affects only boot time),
|
|
or at module load time.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_MIN_HEAP
|
|
tristate "Min heap test"
|
|
depends on DEBUG_KERNEL || m
|
|
help
|
|
Enable this to turn on min heap function tests. This test is
|
|
executed only once during system boot (so affects only boot time),
|
|
or at module load time.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_SORT
|
|
tristate "Array-based sort test"
|
|
depends on DEBUG_KERNEL || m
|
|
help
|
|
This option enables the self-test function of 'sort()' at boot,
|
|
or at module load time.
|
|
|
|
If unsure, say N.
|
|
|
|
config KPROBES_SANITY_TEST
|
|
bool "Kprobes sanity tests"
|
|
depends on DEBUG_KERNEL
|
|
depends on KPROBES
|
|
help
|
|
This option provides for testing basic kprobes functionality on
|
|
boot. Samples of kprobe 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
|
|
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 DEBUG_KERNEL
|
|
help
|
|
A benchmark measuring the performance of the rbtree library.
|
|
Also includes rbtree invariant checks.
|
|
|
|
config REED_SOLOMON_TEST
|
|
tristate "Reed-Solomon library test"
|
|
depends on DEBUG_KERNEL || m
|
|
select REED_SOLOMON
|
|
select REED_SOLOMON_ENC16
|
|
select REED_SOLOMON_DEC16
|
|
help
|
|
This option enables the self-test function of rslib at boot,
|
|
or at module load time.
|
|
|
|
If unsure, say N.
|
|
|
|
config INTERVAL_TREE_TEST
|
|
tristate "Interval tree test"
|
|
depends on DEBUG_KERNEL
|
|
select INTERVAL_TREE
|
|
help
|
|
A benchmark measuring the performance of the interval tree library
|
|
|
|
config PERCPU_TEST
|
|
tristate "Per cpu operations test"
|
|
depends on m && DEBUG_KERNEL
|
|
help
|
|
Enable this option to build test module which validates per-cpu
|
|
operations.
|
|
|
|
If unsure, say N.
|
|
|
|
config ATOMIC64_SELFTEST
|
|
tristate "Perform an atomic64_t self-test"
|
|
help
|
|
Enable this option to test the atomic64_t functions at boot or
|
|
at module load time.
|
|
|
|
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_HEXDUMP
|
|
tristate "Test functions located in the hexdump module at runtime"
|
|
|
|
config TEST_STRING_HELPERS
|
|
tristate "Test functions located in the string_helpers module at runtime"
|
|
|
|
config TEST_STRSCPY
|
|
tristate "Test strscpy*() family of functions at runtime"
|
|
|
|
config TEST_KSTRTOX
|
|
tristate "Test kstrto*() family of functions at runtime"
|
|
|
|
config TEST_PRINTF
|
|
tristate "Test printf() family of functions at runtime"
|
|
|
|
config TEST_BITMAP
|
|
tristate "Test bitmap_*() family of functions at runtime"
|
|
help
|
|
Enable this option to test the bitmap functions at boot.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_UUID
|
|
tristate "Test functions located in the uuid module at runtime"
|
|
|
|
config TEST_XARRAY
|
|
tristate "Test the XArray code at runtime"
|
|
|
|
config TEST_OVERFLOW
|
|
tristate "Test check_*_overflow() functions at runtime"
|
|
|
|
config TEST_RHASHTABLE
|
|
tristate "Perform selftest on resizable hash table"
|
|
help
|
|
Enable this option to test the rhashtable functions at boot.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_HASH
|
|
tristate "Perform selftest on hash functions"
|
|
help
|
|
Enable this option to test the kernel's integer (<linux/hash.h>),
|
|
string (<linux/stringhash.h>), and siphash (<linux/siphash.h>)
|
|
hash functions on boot (or module load).
|
|
|
|
This is intended to help people writing architecture-specific
|
|
optimized versions. If unsure, say N.
|
|
|
|
config TEST_IDA
|
|
tristate "Perform selftest on IDA functions"
|
|
|
|
config TEST_PARMAN
|
|
tristate "Perform selftest on priority array manager"
|
|
depends on PARMAN
|
|
help
|
|
Enable this option to test priority array manager on boot
|
|
(or module load).
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_IRQ_TIMINGS
|
|
bool "IRQ timings selftest"
|
|
depends on IRQ_TIMINGS
|
|
help
|
|
Enable this option to test the irq timings code on boot.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_LKM
|
|
tristate "Test module loading with 'hello world' module"
|
|
depends on m
|
|
help
|
|
This builds the "test_module" module that emits "Hello, world"
|
|
on printk when loaded. It is designed to be used for basic
|
|
evaluation of the module loading subsystem (for example when
|
|
validating module verification). It lacks any extra dependencies,
|
|
and will not normally be loaded by the system unless explicitly
|
|
requested by name.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_BITOPS
|
|
tristate "Test module for compilation of bitops operations"
|
|
depends on m
|
|
help
|
|
This builds the "test_bitops" module that is much like the
|
|
TEST_LKM module except that it does a basic exercise of the
|
|
set/clear_bit macros and get_count_order/long to make sure there are
|
|
no compiler warnings from C=1 sparse checker or -Wextra
|
|
compilations. It has no dependencies and doesn't run or load unless
|
|
explicitly requested by name. for example: modprobe test_bitops.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_VMALLOC
|
|
tristate "Test module for stress/performance analysis of vmalloc allocator"
|
|
default n
|
|
depends on MMU
|
|
depends on m
|
|
help
|
|
This builds the "test_vmalloc" module that should be used for
|
|
stress and performance analysis. So, any new change for vmalloc
|
|
subsystem can be evaluated from performance and stability point
|
|
of view.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_USER_COPY
|
|
tristate "Test user/kernel boundary protections"
|
|
depends on m
|
|
help
|
|
This builds the "test_user_copy" module that runs sanity checks
|
|
on the copy_to/from_user infrastructure, making sure basic
|
|
user/kernel boundary testing is working. If it fails to load,
|
|
a regression has been detected in the user/kernel memory boundary
|
|
protections.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_BPF
|
|
tristate "Test BPF filter functionality"
|
|
depends on m && NET
|
|
help
|
|
This builds the "test_bpf" module that runs various test vectors
|
|
against the BPF interpreter or BPF JIT compiler depending on the
|
|
current setting. This is in particular useful for BPF JIT compiler
|
|
development, but also to run regression tests against changes in
|
|
the interpreter code. It also enables test stubs for eBPF maps and
|
|
verifier used by user space verifier testsuite.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_BLACKHOLE_DEV
|
|
tristate "Test blackhole netdev functionality"
|
|
depends on m && NET
|
|
help
|
|
This builds the "test_blackhole_dev" module that validates the
|
|
data path through this blackhole netdev.
|
|
|
|
If unsure, say N.
|
|
|
|
config FIND_BIT_BENCHMARK
|
|
tristate "Test find_bit functions"
|
|
help
|
|
This builds the "test_find_bit" module that measure find_*_bit()
|
|
functions performance.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_FIRMWARE
|
|
tristate "Test firmware loading via userspace interface"
|
|
depends on FW_LOADER
|
|
help
|
|
This builds the "test_firmware" module that creates a userspace
|
|
interface for testing firmware loading. This can be used to
|
|
control the triggering of firmware loading without needing an
|
|
actual firmware-using device. The contents can be rechecked by
|
|
userspace.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_SYSCTL
|
|
tristate "sysctl test driver"
|
|
depends on PROC_SYSCTL
|
|
help
|
|
This builds the "test_sysctl" module. This driver enables to test the
|
|
proc sysctl interfaces available to drivers safely without affecting
|
|
production knobs which might alter system functionality.
|
|
|
|
If unsure, say N.
|
|
|
|
config BITFIELD_KUNIT
|
|
tristate "KUnit test bitfield functions at runtime"
|
|
depends on KUNIT
|
|
help
|
|
Enable this option to test the bitfield functions at boot.
|
|
|
|
KUnit tests run during boot and output the results to the debug log
|
|
in TAP format (http://testanything.org/). Only useful for kernel devs
|
|
running the KUnit test harness, and not intended for inclusion into a
|
|
production build.
|
|
|
|
For more information on KUnit and unit tests in general please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
If unsure, say N.
|
|
|
|
config RESOURCE_KUNIT_TEST
|
|
tristate "KUnit test for resource API"
|
|
depends on KUNIT
|
|
help
|
|
This builds the resource API unit test.
|
|
Tests the logic of API provided by resource.c and ioport.h.
|
|
For more information on KUnit and unit tests in general please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
If unsure, say N.
|
|
|
|
config SYSCTL_KUNIT_TEST
|
|
tristate "KUnit test for sysctl" if !KUNIT_ALL_TESTS
|
|
depends on KUNIT
|
|
default KUNIT_ALL_TESTS
|
|
help
|
|
This builds the proc sysctl unit test, which runs on boot.
|
|
Tests the API contract and implementation correctness of sysctl.
|
|
For more information on KUnit and unit tests in general please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
If unsure, say N.
|
|
|
|
config LIST_KUNIT_TEST
|
|
tristate "KUnit Test for Kernel Linked-list structures" if !KUNIT_ALL_TESTS
|
|
depends on KUNIT
|
|
default KUNIT_ALL_TESTS
|
|
help
|
|
This builds the linked list KUnit test suite.
|
|
It tests that the API and basic functionality of the list_head type
|
|
and associated macros.
|
|
|
|
KUnit tests run during boot and output the results to the debug log
|
|
in TAP format (https://testanything.org/). Only useful for kernel devs
|
|
running the KUnit test harness, and not intended for inclusion into a
|
|
production build.
|
|
|
|
For more information on KUnit and unit tests in general please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
If unsure, say N.
|
|
|
|
config LINEAR_RANGES_TEST
|
|
tristate "KUnit test for linear_ranges"
|
|
depends on KUNIT
|
|
select LINEAR_RANGES
|
|
help
|
|
This builds the linear_ranges unit test, which runs on boot.
|
|
Tests the linear_ranges logic correctness.
|
|
For more information on KUnit and unit tests in general please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
If unsure, say N.
|
|
|
|
config CMDLINE_KUNIT_TEST
|
|
tristate "KUnit test for cmdline API"
|
|
depends on KUNIT
|
|
help
|
|
This builds the cmdline API unit test.
|
|
Tests the logic of API provided by cmdline.c.
|
|
For more information on KUnit and unit tests in general please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
If unsure, say N.
|
|
|
|
config BITS_TEST
|
|
tristate "KUnit test for bits.h"
|
|
depends on KUNIT
|
|
help
|
|
This builds the bits unit test.
|
|
Tests the logic of macros defined in bits.h.
|
|
For more information on KUnit and unit tests in general please refer
|
|
to the KUnit documentation in Documentation/dev-tools/kunit/.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_UDELAY
|
|
tristate "udelay test driver"
|
|
help
|
|
This builds the "udelay_test" module that helps to make sure
|
|
that udelay() is working properly.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_STATIC_KEYS
|
|
tristate "Test static keys"
|
|
depends on m
|
|
help
|
|
Test the static key interfaces.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_KMOD
|
|
tristate "kmod stress tester"
|
|
depends on m
|
|
depends on NETDEVICES && NET_CORE && INET # for TUN
|
|
depends on BLOCK
|
|
select TEST_LKM
|
|
select XFS_FS
|
|
select TUN
|
|
select BTRFS_FS
|
|
help
|
|
Test the kernel's module loading mechanism: kmod. kmod implements
|
|
support to load modules using the Linux kernel's usermode helper.
|
|
This test provides a series of tests against kmod.
|
|
|
|
Although technically you can either build test_kmod as a module or
|
|
into the kernel we disallow building it into the kernel since
|
|
it stress tests request_module() and this will very likely cause
|
|
some issues by taking over precious threads available from other
|
|
module load requests, ultimately this could be fatal.
|
|
|
|
To run tests run:
|
|
|
|
tools/testing/selftests/kmod/kmod.sh --help
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_DEBUG_VIRTUAL
|
|
tristate "Test CONFIG_DEBUG_VIRTUAL feature"
|
|
depends on DEBUG_VIRTUAL
|
|
help
|
|
Test the kernel's ability to detect incorrect calls to
|
|
virt_to_phys() done against the non-linear part of the
|
|
kernel's virtual address map.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_MEMCAT_P
|
|
tristate "Test memcat_p() helper function"
|
|
help
|
|
Test the memcat_p() helper for correctly merging two
|
|
pointer arrays together.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_LIVEPATCH
|
|
tristate "Test livepatching"
|
|
default n
|
|
depends on DYNAMIC_DEBUG
|
|
depends on LIVEPATCH
|
|
depends on m
|
|
help
|
|
Test kernel livepatching features for correctness. The tests will
|
|
load test modules that will be livepatched in various scenarios.
|
|
|
|
To run all the livepatching tests:
|
|
|
|
make -C tools/testing/selftests TARGETS=livepatch run_tests
|
|
|
|
Alternatively, individual tests may be invoked:
|
|
|
|
tools/testing/selftests/livepatch/test-callbacks.sh
|
|
tools/testing/selftests/livepatch/test-livepatch.sh
|
|
tools/testing/selftests/livepatch/test-shadow-vars.sh
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_OBJAGG
|
|
tristate "Perform selftest on object aggreration manager"
|
|
default n
|
|
depends on OBJAGG
|
|
help
|
|
Enable this option to test object aggregation manager on boot
|
|
(or module load).
|
|
|
|
|
|
config TEST_STACKINIT
|
|
tristate "Test level of stack variable initialization"
|
|
help
|
|
Test if the kernel is zero-initializing stack variables and
|
|
padding. Coverage is controlled by compiler flags,
|
|
CONFIG_GCC_PLUGIN_STRUCTLEAK, CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF,
|
|
or CONFIG_GCC_PLUGIN_STRUCTLEAK_BYREF_ALL.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_MEMINIT
|
|
tristate "Test heap/page initialization"
|
|
help
|
|
Test if the kernel is zero-initializing heap and page allocations.
|
|
This can be useful to test init_on_alloc and init_on_free features.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_HMM
|
|
tristate "Test HMM (Heterogeneous Memory Management)"
|
|
depends on TRANSPARENT_HUGEPAGE
|
|
depends on DEVICE_PRIVATE
|
|
select HMM_MIRROR
|
|
select MMU_NOTIFIER
|
|
help
|
|
This is a pseudo device driver solely for testing HMM.
|
|
Say M here if you want to build the HMM test module.
|
|
Doing so will allow you to run tools/testing/selftest/vm/hmm-tests.
|
|
|
|
If unsure, say N.
|
|
|
|
config TEST_FREE_PAGES
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tristate "Test freeing pages"
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|
help
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|
Test that a memory leak does not occur due to a race between
|
|
freeing a block of pages and a speculative page reference.
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|
Loading this module is safe if your kernel has the bug fixed.
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|
If the bug is not fixed, it will leak gigabytes of memory and
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|
probably OOM your system.
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|
|
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config TEST_FPU
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|
tristate "Test floating point operations in kernel space"
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|
depends on X86 && !KCOV_INSTRUMENT_ALL
|
|
help
|
|
Enable this option to add /sys/kernel/debug/selftest_helpers/test_fpu
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|
which will trigger a sequence of floating point operations. This is used
|
|
for self-testing floating point control register setting in
|
|
kernel_fpu_begin().
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|
|
|
If unsure, say N.
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|
|
|
endif # RUNTIME_TESTING_MENU
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|
|
|
config MEMTEST
|
|
bool "Memtest"
|
|
help
|
|
This option adds a kernel parameter 'memtest', which allows memtest
|
|
to be set.
|
|
memtest=0, mean disabled; -- default
|
|
memtest=1, mean do 1 test pattern;
|
|
...
|
|
memtest=17, mean do 17 test patterns.
|
|
If you are unsure how to answer this question, answer N.
|
|
|
|
|
|
|
|
config HYPERV_TESTING
|
|
bool "Microsoft Hyper-V driver testing"
|
|
default n
|
|
depends on HYPERV && DEBUG_FS
|
|
help
|
|
Select this option to enable Hyper-V vmbus testing.
|
|
|
|
endmenu # "Kernel Testing and Coverage"
|
|
|
|
source "Documentation/Kconfig"
|
|
|
|
endmenu # Kernel hacking
|