+===========================================
Fault injection capabilities infrastructure
===========================================
Available fault injection capabilities
--------------------------------------
-o failslab
+- failslab
injects slab allocation failures. (kmalloc(), kmem_cache_alloc(), ...)
-o fail_page_alloc
+- fail_page_alloc
injects page allocation failures. (alloc_pages(), get_free_pages(), ...)
-o fail_futex
+- fail_futex
injects futex deadlock and uaddr fault errors.
-o fail_make_request
+- fail_make_request
injects disk IO errors on devices permitted by setting
/sys/block/<device>/make-it-fail or
/sys/block/<device>/<partition>/make-it-fail. (generic_make_request())
-o fail_mmc_request
+- fail_mmc_request
injects MMC data errors on devices permitted by setting
debugfs entries under /sys/kernel/debug/mmc0/fail_mmc_request
-o fail_function
+- fail_function
injects error return on specific functions, which are marked by
ALLOW_ERROR_INJECTION() macro, by setting debugfs entries
under /sys/kernel/debug/fail_function. No boot option supported.
-o NVMe fault injection
+- NVMe fault injection
inject NVMe status code and retry flag on devices permitted by setting
debugfs entries under /sys/kernel/debug/nvme*/fault_inject. The default
Configure fault-injection capabilities behavior
-----------------------------------------------
-o debugfs entries
+debugfs entries
+^^^^^^^^^^^^^^^
fault-inject-debugfs kernel module provides some debugfs entries for runtime
configuration of fault-injection capabilities.
- /sys/kernel/debug/fail*/probability:
likelihood of failure injection, in percent.
+
Format: <percent>
Note that one-failure-per-hundred is a very high error rate
- /sys/kernel/debug/fail*/verbose
Format: { 0 | 1 | 2 }
+
specifies the verbosity of the messages when failure is
injected. '0' means no messages; '1' will print only a single
log line per failure; '2' will print a call trace too -- useful
- /sys/kernel/debug/fail*/task-filter:
Format: { 'Y' | 'N' }
+
A value of 'N' disables filtering by process (default).
Any positive value limits failures to only processes indicated by
/proc/<pid>/make-it-fail==1.
-- /sys/kernel/debug/fail*/require-start:
-- /sys/kernel/debug/fail*/require-end:
-- /sys/kernel/debug/fail*/reject-start:
-- /sys/kernel/debug/fail*/reject-end:
+- /sys/kernel/debug/fail*/require-start,
+ /sys/kernel/debug/fail*/require-end,
+ /sys/kernel/debug/fail*/reject-start,
+ /sys/kernel/debug/fail*/reject-end:
specifies the range of virtual addresses tested during
stacktrace walking. Failure is injected only if some caller
- /sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem:
Format: { 'Y' | 'N' }
+
default is 'N', setting it to 'Y' won't inject failures into
highmem/user allocations.
- /sys/kernel/debug/fail_page_alloc/ignore-gfp-wait:
Format: { 'Y' | 'N' }
+
default is 'N', setting it to 'Y' will inject failures
only into non-sleep allocations (GFP_ATOMIC allocations).
- /sys/kernel/debug/fail_futex/ignore-private:
Format: { 'Y' | 'N' }
+
default is 'N', setting it to 'Y' will disable failure injections
when dealing with private (address space) futexes.
- /sys/kernel/debug/fail_function/inject:
Format: { 'function-name' | '!function-name' | '' }
+
specifies the target function of error injection by name.
If the function name leads '!' prefix, given function is
removed from injection list. If nothing specified ('')
function for given function. This will be created when
user specifies new injection entry.
-o Boot option
+Boot option
+^^^^^^^^^^^
In order to inject faults while debugfs is not available (early boot time),
-use the boot option:
+use the boot option::
failslab=
fail_page_alloc=
fail_futex=
mmc_core.fail_request=<interval>,<probability>,<space>,<times>
-o proc entries
+proc entries
+^^^^^^^^^^^^
-- /proc/<pid>/fail-nth:
-- /proc/self/task/<tid>/fail-nth:
+- /proc/<pid>/fail-nth,
+ /proc/self/task/<tid>/fail-nth:
Write to this file of integer N makes N-th call in the task fail.
Read from this file returns a integer value. A value of '0' indicates
How to add new fault injection capability
-----------------------------------------
-o #include <linux/fault-inject.h>
+- #include <linux/fault-inject.h>
-o define the fault attributes
+- define the fault attributes
DECLARE_FAULT_ATTR(name);
Please see the definition of struct fault_attr in fault-inject.h
for details.
-o provide a way to configure fault attributes
+- provide a way to configure fault attributes
- boot option
single kernel module, it is better to provide module parameters to
configure the fault attributes.
-o add a hook to insert failures
+- add a hook to insert failures
- Upon should_fail() returning true, client code should inject a failure.
+ Upon should_fail() returning true, client code should inject a failure:
should_fail(attr, size);
Application Examples
--------------------
-o Inject slab allocation failures into module init/exit code
+- Inject slab allocation failures into module init/exit code::
-#!/bin/bash
+ #!/bin/bash
-FAILTYPE=failslab
-echo Y > /sys/kernel/debug/$FAILTYPE/task-filter
-echo 10 > /sys/kernel/debug/$FAILTYPE/probability
-echo 100 > /sys/kernel/debug/$FAILTYPE/interval
-echo -1 > /sys/kernel/debug/$FAILTYPE/times
-echo 0 > /sys/kernel/debug/$FAILTYPE/space
-echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
-echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
+ FAILTYPE=failslab
+ echo Y > /sys/kernel/debug/$FAILTYPE/task-filter
+ echo 10 > /sys/kernel/debug/$FAILTYPE/probability
+ echo 100 > /sys/kernel/debug/$FAILTYPE/interval
+ echo -1 > /sys/kernel/debug/$FAILTYPE/times
+ echo 0 > /sys/kernel/debug/$FAILTYPE/space
+ echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
+ echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
-faulty_system()
-{
+ faulty_system()
+ {
bash -c "echo 1 > /proc/self/make-it-fail && exec $*"
-}
+ }
-if [ $# -eq 0 ]
-then
+ if [ $# -eq 0 ]
+ then
echo "Usage: $0 modulename [ modulename ... ]"
exit 1
-fi
+ fi
-for m in $*
-do
+ for m in $*
+ do
echo inserting $m...
faulty_system modprobe $m
echo removing $m...
faulty_system modprobe -r $m
-done
+ done
------------------------------------------------------------------------------
-o Inject page allocation failures only for a specific module
+- Inject page allocation failures only for a specific module::
-#!/bin/bash
+ #!/bin/bash
-FAILTYPE=fail_page_alloc
-module=$1
+ FAILTYPE=fail_page_alloc
+ module=$1
-if [ -z $module ]
-then
+ if [ -z $module ]
+ then
echo "Usage: $0 <modulename>"
exit 1
-fi
+ fi
-modprobe $module
+ modprobe $module
-if [ ! -d /sys/module/$module/sections ]
-then
+ if [ ! -d /sys/module/$module/sections ]
+ then
echo Module $module is not loaded
exit 1
-fi
+ fi
-cat /sys/module/$module/sections/.text > /sys/kernel/debug/$FAILTYPE/require-start
-cat /sys/module/$module/sections/.data > /sys/kernel/debug/$FAILTYPE/require-end
+ cat /sys/module/$module/sections/.text > /sys/kernel/debug/$FAILTYPE/require-start
+ cat /sys/module/$module/sections/.data > /sys/kernel/debug/$FAILTYPE/require-end
-echo N > /sys/kernel/debug/$FAILTYPE/task-filter
-echo 10 > /sys/kernel/debug/$FAILTYPE/probability
-echo 100 > /sys/kernel/debug/$FAILTYPE/interval
-echo -1 > /sys/kernel/debug/$FAILTYPE/times
-echo 0 > /sys/kernel/debug/$FAILTYPE/space
-echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
-echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
-echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-highmem
-echo 10 > /sys/kernel/debug/$FAILTYPE/stacktrace-depth
+ echo N > /sys/kernel/debug/$FAILTYPE/task-filter
+ echo 10 > /sys/kernel/debug/$FAILTYPE/probability
+ echo 100 > /sys/kernel/debug/$FAILTYPE/interval
+ echo -1 > /sys/kernel/debug/$FAILTYPE/times
+ echo 0 > /sys/kernel/debug/$FAILTYPE/space
+ echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
+ echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
+ echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-highmem
+ echo 10 > /sys/kernel/debug/$FAILTYPE/stacktrace-depth
-trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
+ trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
-echo "Injecting errors into the module $module... (interrupt to stop)"
-sleep 1000000
+ echo "Injecting errors into the module $module... (interrupt to stop)"
+ sleep 1000000
------------------------------------------------------------------------------
-o Inject open_ctree error while btrfs mount
-
-#!/bin/bash
-
-rm -f testfile.img
-dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
-DEVICE=$(losetup --show -f testfile.img)
-mkfs.btrfs -f $DEVICE
-mkdir -p tmpmnt
-
-FAILTYPE=fail_function
-FAILFUNC=open_ctree
-echo $FAILFUNC > /sys/kernel/debug/$FAILTYPE/inject
-echo -12 > /sys/kernel/debug/$FAILTYPE/$FAILFUNC/retval
-echo N > /sys/kernel/debug/$FAILTYPE/task-filter
-echo 100 > /sys/kernel/debug/$FAILTYPE/probability
-echo 0 > /sys/kernel/debug/$FAILTYPE/interval
-echo -1 > /sys/kernel/debug/$FAILTYPE/times
-echo 0 > /sys/kernel/debug/$FAILTYPE/space
-echo 1 > /sys/kernel/debug/$FAILTYPE/verbose
-
-mount -t btrfs $DEVICE tmpmnt
-if [ $? -ne 0 ]
-then
+- Inject open_ctree error while btrfs mount::
+
+ #!/bin/bash
+
+ rm -f testfile.img
+ dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1
+ DEVICE=$(losetup --show -f testfile.img)
+ mkfs.btrfs -f $DEVICE
+ mkdir -p tmpmnt
+
+ FAILTYPE=fail_function
+ FAILFUNC=open_ctree
+ echo $FAILFUNC > /sys/kernel/debug/$FAILTYPE/inject
+ echo -12 > /sys/kernel/debug/$FAILTYPE/$FAILFUNC/retval
+ echo N > /sys/kernel/debug/$FAILTYPE/task-filter
+ echo 100 > /sys/kernel/debug/$FAILTYPE/probability
+ echo 0 > /sys/kernel/debug/$FAILTYPE/interval
+ echo -1 > /sys/kernel/debug/$FAILTYPE/times
+ echo 0 > /sys/kernel/debug/$FAILTYPE/space
+ echo 1 > /sys/kernel/debug/$FAILTYPE/verbose
+
+ mount -t btrfs $DEVICE tmpmnt
+ if [ $? -ne 0 ]
+ then
echo "SUCCESS!"
-else
+ else
echo "FAILED!"
umount tmpmnt
-fi
+ fi
-echo > /sys/kernel/debug/$FAILTYPE/inject
+ echo > /sys/kernel/debug/$FAILTYPE/inject
-rmdir tmpmnt
-losetup -d $DEVICE
-rm testfile.img
+ rmdir tmpmnt
+ losetup -d $DEVICE
+ rm testfile.img
Tool to run command with failslab or fail_page_alloc
Examples:
Run a command "make -C tools/testing/selftests/ run_tests" with injecting slab
-allocation failure.
+allocation failure::
# ./tools/testing/fault-injection/failcmd.sh \
-- make -C tools/testing/selftests/ run_tests
Same as above except to specify 100 times failures at most instead of one time
-at most by default.
+at most by default::
# ./tools/testing/fault-injection/failcmd.sh --times=100 \
-- make -C tools/testing/selftests/ run_tests
Same as above except to inject page allocation failure instead of slab
-allocation failure.
+allocation failure::
# env FAILCMD_TYPE=fail_page_alloc \
./tools/testing/fault-injection/failcmd.sh --times=100 \
- -- make -C tools/testing/selftests/ run_tests
+ -- make -C tools/testing/selftests/ run_tests
Systematic faults using fail-nth
---------------------------------
The following code systematically faults 0-th, 1-st, 2-nd and so on
-capabilities in the socketpair() system call.
-
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/socket.h>
-#include <sys/syscall.h>
-#include <fcntl.h>
-#include <unistd.h>
-#include <string.h>
-#include <stdlib.h>
-#include <stdio.h>
-#include <errno.h>
-
-int main()
-{
+capabilities in the socketpair() system call::
+
+ #include <sys/types.h>
+ #include <sys/stat.h>
+ #include <sys/socket.h>
+ #include <sys/syscall.h>
+ #include <fcntl.h>
+ #include <unistd.h>
+ #include <string.h>
+ #include <stdlib.h>
+ #include <stdio.h>
+ #include <errno.h>
+
+ int main()
+ {
int i, err, res, fail_nth, fds[2];
char buf[128];
break;
}
return 0;
-}
-
-An example output:
-
-1-th fault Y: res=-1/23
-2-th fault Y: res=-1/23
-3-th fault Y: res=-1/12
-4-th fault Y: res=-1/12
-5-th fault Y: res=-1/23
-6-th fault Y: res=-1/23
-7-th fault Y: res=-1/23
-8-th fault Y: res=-1/12
-9-th fault Y: res=-1/12
-10-th fault Y: res=-1/12
-11-th fault Y: res=-1/12
-12-th fault Y: res=-1/12
-13-th fault Y: res=-1/12
-14-th fault Y: res=-1/12
-15-th fault Y: res=-1/12
-16-th fault N: res=0/12
+ }
+
+An example output::
+
+ 1-th fault Y: res=-1/23
+ 2-th fault Y: res=-1/23
+ 3-th fault Y: res=-1/12
+ 4-th fault Y: res=-1/12
+ 5-th fault Y: res=-1/23
+ 6-th fault Y: res=-1/23
+ 7-th fault Y: res=-1/23
+ 8-th fault Y: res=-1/12
+ 9-th fault Y: res=-1/12
+ 10-th fault Y: res=-1/12
+ 11-th fault Y: res=-1/12
+ 12-th fault Y: res=-1/12
+ 13-th fault Y: res=-1/12
+ 14-th fault Y: res=-1/12
+ 15-th fault Y: res=-1/12
+ 16-th fault N: res=0/12
--- /dev/null
+:orphan:
+
+===============
+fault-injection
+===============
+
+.. toctree::
+ :maxdepth: 1
+
+ fault-injection
+ notifier-error-inject
+ nvme-fault-injection
+ provoke-crashes
+
+.. only:: subproject and html
+
+ Indices
+ =======
+
+ * :ref:`genindex`
PM notifier error injection module
----------------------------------
This feature is controlled through debugfs interface
-/sys/kernel/debug/notifier-error-inject/pm/actions/<notifier event>/error
+
+ /sys/kernel/debug/notifier-error-inject/pm/actions/<notifier event>/error
Possible PM notifier events to be failed are:
* PM_SUSPEND_PREPARE
* PM_RESTORE_PREPARE
-Example: Inject PM suspend error (-12 = -ENOMEM)
+Example: Inject PM suspend error (-12 = -ENOMEM)::
# cd /sys/kernel/debug/notifier-error-inject/pm/
# echo -12 > actions/PM_SUSPEND_PREPARE/error
Memory hotplug notifier error injection module
----------------------------------------------
This feature is controlled through debugfs interface
-/sys/kernel/debug/notifier-error-inject/memory/actions/<notifier event>/error
+
+ /sys/kernel/debug/notifier-error-inject/memory/actions/<notifier event>/error
Possible memory notifier events to be failed are:
* MEM_GOING_ONLINE
* MEM_GOING_OFFLINE
-Example: Inject memory hotplug offline error (-12 == -ENOMEM)
+Example: Inject memory hotplug offline error (-12 == -ENOMEM)::
# cd /sys/kernel/debug/notifier-error-inject/memory
# echo -12 > actions/MEM_GOING_OFFLINE/error
powerpc pSeries reconfig notifier error injection module
--------------------------------------------------------
This feature is controlled through debugfs interface
-/sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions/<notifier event>/error
+
+ /sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions/<notifier event>/error
Possible pSeries reconfig notifier events to be failed are:
Netdevice notifier error injection module
----------------------------------------------
This feature is controlled through debugfs interface
-/sys/kernel/debug/notifier-error-inject/netdev/actions/<notifier event>/error
+
+ /sys/kernel/debug/notifier-error-inject/netdev/actions/<notifier event>/error
Netdevice notifier events which can be failed are:
* NETDEV_PRECHANGEUPPER
* NETDEV_CHANGEUPPER
-Example: Inject netdevice mtu change error (-22 == -EINVAL)
+Example: Inject netdevice mtu change error (-22 == -EINVAL)::
# cd /sys/kernel/debug/notifier-error-inject/netdev
# echo -22 > actions/NETDEV_CHANGEMTU/error
--- /dev/null
+NVMe Fault Injection
+====================
+Linux's fault injection framework provides a systematic way to support
+error injection via debugfs in the /sys/kernel/debug directory. When
+enabled, the default NVME_SC_INVALID_OPCODE with no retry will be
+injected into the nvme_end_request. Users can change the default status
+code and no retry flag via the debugfs. The list of Generic Command
+Status can be found in include/linux/nvme.h
+
+Following examples show how to inject an error into the nvme.
+
+First, enable CONFIG_FAULT_INJECTION_DEBUG_FS kernel config,
+recompile the kernel. After booting up the kernel, do the
+following.
+
+Example 1: Inject default status code with no retry
+---------------------------------------------------
+
+::
+
+ mount /dev/nvme0n1 /mnt
+ echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/times
+ echo 100 > /sys/kernel/debug/nvme0n1/fault_inject/probability
+ cp a.file /mnt
+
+Expected Result::
+
+ cp: cannot stat ‘/mnt/a.file’: Input/output error
+
+Message from dmesg::
+
+ FAULT_INJECTION: forcing a failure.
+ name fault_inject, interval 1, probability 100, space 0, times 1
+ CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc8+ #2
+ Hardware name: innotek GmbH VirtualBox/VirtualBox,
+ BIOS VirtualBox 12/01/2006
+ Call Trace:
+ <IRQ>
+ dump_stack+0x5c/0x7d
+ should_fail+0x148/0x170
+ nvme_should_fail+0x2f/0x50 [nvme_core]
+ nvme_process_cq+0xe7/0x1d0 [nvme]
+ nvme_irq+0x1e/0x40 [nvme]
+ __handle_irq_event_percpu+0x3a/0x190
+ handle_irq_event_percpu+0x30/0x70
+ handle_irq_event+0x36/0x60
+ handle_fasteoi_irq+0x78/0x120
+ handle_irq+0xa7/0x130
+ ? tick_irq_enter+0xa8/0xc0
+ do_IRQ+0x43/0xc0
+ common_interrupt+0xa2/0xa2
+ </IRQ>
+ RIP: 0010:native_safe_halt+0x2/0x10
+ RSP: 0018:ffffffff82003e90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd
+ RAX: ffffffff817a10c0 RBX: ffffffff82012480 RCX: 0000000000000000
+ RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
+ RBP: 0000000000000000 R08: 000000008e38ce64 R09: 0000000000000000
+ R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82012480
+ R13: ffffffff82012480 R14: 0000000000000000 R15: 0000000000000000
+ ? __sched_text_end+0x4/0x4
+ default_idle+0x18/0xf0
+ do_idle+0x150/0x1d0
+ cpu_startup_entry+0x6f/0x80
+ start_kernel+0x4c4/0x4e4
+ ? set_init_arg+0x55/0x55
+ secondary_startup_64+0xa5/0xb0
+ print_req_error: I/O error, dev nvme0n1, sector 9240
+ EXT4-fs error (device nvme0n1): ext4_find_entry:1436:
+ inode #2: comm cp: reading directory lblock 0
+
+Example 2: Inject default status code with retry
+------------------------------------------------
+
+::
+
+ mount /dev/nvme0n1 /mnt
+ echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/times
+ echo 100 > /sys/kernel/debug/nvme0n1/fault_inject/probability
+ echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/status
+ echo 0 > /sys/kernel/debug/nvme0n1/fault_inject/dont_retry
+
+ cp a.file /mnt
+
+Expected Result::
+
+ command success without error
+
+Message from dmesg::
+
+ FAULT_INJECTION: forcing a failure.
+ name fault_inject, interval 1, probability 100, space 0, times 1
+ CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.15.0-rc8+ #4
+ Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
+ Call Trace:
+ <IRQ>
+ dump_stack+0x5c/0x7d
+ should_fail+0x148/0x170
+ nvme_should_fail+0x30/0x60 [nvme_core]
+ nvme_loop_queue_response+0x84/0x110 [nvme_loop]
+ nvmet_req_complete+0x11/0x40 [nvmet]
+ nvmet_bio_done+0x28/0x40 [nvmet]
+ blk_update_request+0xb0/0x310
+ blk_mq_end_request+0x18/0x60
+ flush_smp_call_function_queue+0x3d/0xf0
+ smp_call_function_single_interrupt+0x2c/0xc0
+ call_function_single_interrupt+0xa2/0xb0
+ </IRQ>
+ RIP: 0010:native_safe_halt+0x2/0x10
+ RSP: 0018:ffffc9000068bec0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff04
+ RAX: ffffffff817a10c0 RBX: ffff88011a3c9680 RCX: 0000000000000000
+ RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
+ RBP: 0000000000000001 R08: 000000008e38c131 R09: 0000000000000000
+ R10: 0000000000000000 R11: 0000000000000000 R12: ffff88011a3c9680
+ R13: ffff88011a3c9680 R14: 0000000000000000 R15: 0000000000000000
+ ? __sched_text_end+0x4/0x4
+ default_idle+0x18/0xf0
+ do_idle+0x150/0x1d0
+ cpu_startup_entry+0x6f/0x80
+ start_secondary+0x187/0x1e0
+ secondary_startup_64+0xa5/0xb0
+++ /dev/null
-NVMe Fault Injection
-====================
-Linux's fault injection framework provides a systematic way to support
-error injection via debugfs in the /sys/kernel/debug directory. When
-enabled, the default NVME_SC_INVALID_OPCODE with no retry will be
-injected into the nvme_end_request. Users can change the default status
-code and no retry flag via the debugfs. The list of Generic Command
-Status can be found in include/linux/nvme.h
-
-Following examples show how to inject an error into the nvme.
-
-First, enable CONFIG_FAULT_INJECTION_DEBUG_FS kernel config,
-recompile the kernel. After booting up the kernel, do the
-following.
-
-Example 1: Inject default status code with no retry
----------------------------------------------------
-
-mount /dev/nvme0n1 /mnt
-echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/times
-echo 100 > /sys/kernel/debug/nvme0n1/fault_inject/probability
-cp a.file /mnt
-
-Expected Result:
-
-cp: cannot stat ‘/mnt/a.file’: Input/output error
-
-Message from dmesg:
-
-FAULT_INJECTION: forcing a failure.
-name fault_inject, interval 1, probability 100, space 0, times 1
-CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.15.0-rc8+ #2
-Hardware name: innotek GmbH VirtualBox/VirtualBox,
-BIOS VirtualBox 12/01/2006
-Call Trace:
- <IRQ>
- dump_stack+0x5c/0x7d
- should_fail+0x148/0x170
- nvme_should_fail+0x2f/0x50 [nvme_core]
- nvme_process_cq+0xe7/0x1d0 [nvme]
- nvme_irq+0x1e/0x40 [nvme]
- __handle_irq_event_percpu+0x3a/0x190
- handle_irq_event_percpu+0x30/0x70
- handle_irq_event+0x36/0x60
- handle_fasteoi_irq+0x78/0x120
- handle_irq+0xa7/0x130
- ? tick_irq_enter+0xa8/0xc0
- do_IRQ+0x43/0xc0
- common_interrupt+0xa2/0xa2
- </IRQ>
-RIP: 0010:native_safe_halt+0x2/0x10
-RSP: 0018:ffffffff82003e90 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffdd
-RAX: ffffffff817a10c0 RBX: ffffffff82012480 RCX: 0000000000000000
-RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
-RBP: 0000000000000000 R08: 000000008e38ce64 R09: 0000000000000000
-R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff82012480
-R13: ffffffff82012480 R14: 0000000000000000 R15: 0000000000000000
- ? __sched_text_end+0x4/0x4
- default_idle+0x18/0xf0
- do_idle+0x150/0x1d0
- cpu_startup_entry+0x6f/0x80
- start_kernel+0x4c4/0x4e4
- ? set_init_arg+0x55/0x55
- secondary_startup_64+0xa5/0xb0
- print_req_error: I/O error, dev nvme0n1, sector 9240
-EXT4-fs error (device nvme0n1): ext4_find_entry:1436:
-inode #2: comm cp: reading directory lblock 0
-
-Example 2: Inject default status code with retry
-------------------------------------------------
-
-mount /dev/nvme0n1 /mnt
-echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/times
-echo 100 > /sys/kernel/debug/nvme0n1/fault_inject/probability
-echo 1 > /sys/kernel/debug/nvme0n1/fault_inject/status
-echo 0 > /sys/kernel/debug/nvme0n1/fault_inject/dont_retry
-
-cp a.file /mnt
-
-Expected Result:
-
-command success without error
-
-Message from dmesg:
-
-FAULT_INJECTION: forcing a failure.
-name fault_inject, interval 1, probability 100, space 0, times 1
-CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.15.0-rc8+ #4
-Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006
-Call Trace:
- <IRQ>
- dump_stack+0x5c/0x7d
- should_fail+0x148/0x170
- nvme_should_fail+0x30/0x60 [nvme_core]
- nvme_loop_queue_response+0x84/0x110 [nvme_loop]
- nvmet_req_complete+0x11/0x40 [nvmet]
- nvmet_bio_done+0x28/0x40 [nvmet]
- blk_update_request+0xb0/0x310
- blk_mq_end_request+0x18/0x60
- flush_smp_call_function_queue+0x3d/0xf0
- smp_call_function_single_interrupt+0x2c/0xc0
- call_function_single_interrupt+0xa2/0xb0
- </IRQ>
-RIP: 0010:native_safe_halt+0x2/0x10
-RSP: 0018:ffffc9000068bec0 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff04
-RAX: ffffffff817a10c0 RBX: ffff88011a3c9680 RCX: 0000000000000000
-RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
-RBP: 0000000000000001 R08: 000000008e38c131 R09: 0000000000000000
-R10: 0000000000000000 R11: 0000000000000000 R12: ffff88011a3c9680
-R13: ffff88011a3c9680 R14: 0000000000000000 R15: 0000000000000000
- ? __sched_text_end+0x4/0x4
- default_idle+0x18/0xf0
- do_idle+0x150/0x1d0
- cpu_startup_entry+0x6f/0x80
- start_secondary+0x187/0x1e0
- secondary_startup_64+0xa5/0xb0
--- /dev/null
+===============
+Provoke crashes
+===============
+
+The lkdtm module provides an interface to crash or injure the kernel at
+predefined crashpoints to evaluate the reliability of crash dumps obtained
+using different dumping solutions. The module uses KPROBEs to instrument
+crashing points, but can also crash the kernel directly without KRPOBE
+support.
+
+
+You can provide the way either through module arguments when inserting
+the module, or through a debugfs interface.
+
+Usage::
+
+ insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<>
+ [cpoint_count={>0}]
+
+recur_count
+ Recursion level for the stack overflow test. Default is 10.
+
+cpoint_name
+ Crash point where the kernel is to be crashed. It can be
+ one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY,
+ FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD,
+ IDE_CORE_CP, DIRECT
+
+cpoint_type
+ Indicates the action to be taken on hitting the crash point.
+ It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW,
+ CORRUPT_STACK, UNALIGNED_LOAD_STORE_WRITE, OVERWRITE_ALLOCATION,
+ WRITE_AFTER_FREE,
+
+cpoint_count
+ Indicates the number of times the crash point is to be hit
+ to trigger an action. The default is 10.
+
+You can also induce failures by mounting debugfs and writing the type to
+<mountpoint>/provoke-crash/<crashpoint>. E.g.::
+
+ mount -t debugfs debugfs /mnt
+ echo EXCEPTION > /mnt/provoke-crash/INT_HARDWARE_ENTRY
+
+
+A special file is `DIRECT` which will induce the crash directly without
+KPROBE instrumentation. This mode is the only one available when the module
+is built on a kernel without KPROBEs support.
+++ /dev/null
-The lkdtm module provides an interface to crash or injure the kernel at
-predefined crashpoints to evaluate the reliability of crash dumps obtained
-using different dumping solutions. The module uses KPROBEs to instrument
-crashing points, but can also crash the kernel directly without KRPOBE
-support.
-
-
-You can provide the way either through module arguments when inserting
-the module, or through a debugfs interface.
-
-Usage: insmod lkdtm.ko [recur_count={>0}] cpoint_name=<> cpoint_type=<>
- [cpoint_count={>0}]
-
- recur_count : Recursion level for the stack overflow test. Default is 10.
-
- cpoint_name : Crash point where the kernel is to be crashed. It can be
- one of INT_HARDWARE_ENTRY, INT_HW_IRQ_EN, INT_TASKLET_ENTRY,
- FS_DEVRW, MEM_SWAPOUT, TIMERADD, SCSI_DISPATCH_CMD,
- IDE_CORE_CP, DIRECT
-
- cpoint_type : Indicates the action to be taken on hitting the crash point.
- It can be one of PANIC, BUG, EXCEPTION, LOOP, OVERFLOW,
- CORRUPT_STACK, UNALIGNED_LOAD_STORE_WRITE, OVERWRITE_ALLOCATION,
- WRITE_AFTER_FREE,
-
- cpoint_count : Indicates the number of times the crash point is to be hit
- to trigger an action. The default is 10.
-
-You can also induce failures by mounting debugfs and writing the type to
-<mountpoint>/provoke-crash/<crashpoint>. E.g.,
-
- mount -t debugfs debugfs /mnt
- echo EXCEPTION > /mnt/provoke-crash/INT_HARDWARE_ENTRY
-
-
-A special file is `DIRECT' which will induce the crash directly without
-KPROBE instrumentation. This mode is the only one available when the module
-is built on a kernel without KPROBEs support.
fail; these failures can be restricted to a specific range of code.
Running with fault injection enabled allows the programmer to see how the
code responds when things go badly. See
-Documentation/fault-injection/fault-injection.txt for more information on
+Documentation/fault-injection/fault-injection.rst for more information on
how to use this facility.
Other kinds of errors can be found with the "sparse" static analysis tool.
possono essere ridotti ad uno specifico pezzo di codice. Procedere con
l'inserimento dei fallimenti attivo permette al programmatore di verificare
come il codice risponde quando le cose vanno male. Consultate:
-Documentation/fault-injection/fault-injection.txt per avere maggiori
+Documentation/fault-injection/fault-injection.rst per avere maggiori
informazioni su come utilizzare questo strumento.
Altre tipologie di errori possono essere riscontrati con lo strumento di
启用故障注入后，内存分配的可配置百分比将失败；这些失败可以限制在特定的代码
范围内。在启用了故障注入的情况下运行，程序员可以看到当情况恶化时代码如何响
应。有关如何使用此工具的详细信息，请参阅
-Documentation/fault-injection/fault-injection.txt。
+Documentation/fault-injection/fault-injection.rst。
使用“sparse”静态分析工具可以发现其他类型的错误。对于sparse，可以警告程序员
用户空间和内核空间地址之间的混淆、big endian和small endian数量的混合、在需
*
* Debugfs support added by Simon Kagstrom <simon.kagstrom@netinsight.net>
*
- * See Documentation/fault-injection/provoke-crashes.txt for instructions
+ * See Documentation/fault-injection/provoke-crashes.rst for instructions
*/
#include "lkdtm.h"
#include <linux/fs.h>
/*
* For explanation of the elements of this struct, see
- * Documentation/fault-injection/fault-injection.txt
+ * Documentation/fault-injection/fault-injection.rst
*/
struct fault_attr {
unsigned long probability;
called lkdtm.
Documentation on how to use the module can be found in
- Documentation/fault-injection/provoke-crashes.txt
+ Documentation/fault-injection/provoke-crashes.rst
config TEST_LIST_SORT
tristate "Linked list sorting test"
--interval=value, --space=value, --verbose=value, --task-filter=value,
--stacktrace-depth=value, --require-start=value, --require-end=value,
--reject-start=value, --reject-end=value, --ignore-gfp-wait=value
- See Documentation/fault-injection/fault-injection.txt for more
+ See Documentation/fault-injection/fault-injection.rst for more
information
failslab options:
projects / platform / kernel / linux-rpi.git / commitdiff