From 10ffebbed5503b1830c7920ef528075785351be6 Mon Sep 17 00:00:00 2001 From: Mauro Carvalho Chehab Date: Wed, 12 Jun 2019 14:52:44 -0300 Subject: docs: fault-injection: convert docs to ReST and rename to *.rst The conversion is actually: - add blank lines and identation in order to identify paragraphs; - fix tables markups; - add some lists markups; - mark literal blocks; - adjust title markups. At its new index.rst, let's add a :orphan: while this is not linked to the main index.rst file, in order to avoid build warnings. Signed-off-by: Mauro Carvalho Chehab Acked-by: Federico Vaga Signed-off-by: Jonathan Corbet --- Documentation/fault-injection/fault-injection.rst | 446 +++++++++++++++++++++ Documentation/fault-injection/fault-injection.txt | 435 -------------------- Documentation/fault-injection/index.rst | 20 + .../fault-injection/notifier-error-inject.rst | 98 +++++ .../fault-injection/notifier-error-inject.txt | 94 ----- .../fault-injection/nvme-fault-injection.rst | 120 ++++++ .../fault-injection/nvme-fault-injection.txt | 116 ------ Documentation/fault-injection/provoke-crashes.rst | 48 +++ Documentation/fault-injection/provoke-crashes.txt | 38 -- 9 files changed, 732 insertions(+), 683 deletions(-) create mode 100644 Documentation/fault-injection/fault-injection.rst delete mode 100644 Documentation/fault-injection/fault-injection.txt create mode 100644 Documentation/fault-injection/index.rst create mode 100644 Documentation/fault-injection/notifier-error-inject.rst delete mode 100644 Documentation/fault-injection/notifier-error-inject.txt create mode 100644 Documentation/fault-injection/nvme-fault-injection.rst delete mode 100644 Documentation/fault-injection/nvme-fault-injection.txt create mode 100644 Documentation/fault-injection/provoke-crashes.rst delete mode 100644 Documentation/fault-injection/provoke-crashes.txt (limited to 'Documentation/fault-injection') diff --git a/Documentation/fault-injection/fault-injection.rst b/Documentation/fault-injection/fault-injection.rst new file mode 100644 index 000000000000..f51bb21d20e4 --- /dev/null +++ b/Documentation/fault-injection/fault-injection.rst @@ -0,0 +1,446 @@ +=========================================== +Fault injection capabilities infrastructure +=========================================== + +See also drivers/md/md-faulty.c and "every_nth" module option for scsi_debug. + + +Available fault injection capabilities +-------------------------------------- + +- failslab + + injects slab allocation failures. (kmalloc(), kmem_cache_alloc(), ...) + +- fail_page_alloc + + injects page allocation failures. (alloc_pages(), get_free_pages(), ...) + +- fail_futex + + injects futex deadlock and uaddr fault errors. + +- fail_make_request + + injects disk IO errors on devices permitted by setting + /sys/block//make-it-fail or + /sys/block///make-it-fail. (generic_make_request()) + +- fail_mmc_request + + injects MMC data errors on devices permitted by setting + debugfs entries under /sys/kernel/debug/mmc0/fail_mmc_request + +- 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. + +- 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 + status code is NVME_SC_INVALID_OPCODE with no retry. The status code and + retry flag can be set via the debugfs. + + +Configure fault-injection capabilities behavior +----------------------------------------------- + +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: + + Note that one-failure-per-hundred is a very high error rate + for some testcases. Consider setting probability=100 and configure + /sys/kernel/debug/fail*/interval for such testcases. + +- /sys/kernel/debug/fail*/interval: + + specifies the interval between failures, for calls to + should_fail() that pass all the other tests. + + Note that if you enable this, by setting interval>1, you will + probably want to set probability=100. + +- /sys/kernel/debug/fail*/times: + + specifies how many times failures may happen at most. + A value of -1 means "no limit". + +- /sys/kernel/debug/fail*/space: + + specifies an initial resource "budget", decremented by "size" + on each call to should_fail(,size). Failure injection is + suppressed until "space" reaches zero. + +- /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 + to debug the problems revealed by fault injection. + +- /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//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: + + specifies the range of virtual addresses tested during + stacktrace walking. Failure is injected only if some caller + in the walked stacktrace lies within the required range, and + none lies within the rejected range. + Default required range is [0,ULONG_MAX) (whole of virtual address space). + Default rejected range is [0,0). + +- /sys/kernel/debug/fail*/stacktrace-depth: + + specifies the maximum stacktrace depth walked during search + for a caller within [require-start,require-end) OR + [reject-start,reject-end). + +- /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/failslab/ignore-gfp-wait: +- /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_page_alloc/min-order: + + specifies the minimum page allocation order to be injected + failures. + +- /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 ('') + injection list is cleared. + +- /sys/kernel/debug/fail_function/injectable: + + (read only) shows error injectable functions and what type of + error values can be specified. The error type will be one of + below; + - NULL: retval must be 0. + - ERRNO: retval must be -1 to -MAX_ERRNO (-4096). + - ERR_NULL: retval must be 0 or -1 to -MAX_ERRNO (-4096). + +- /sys/kernel/debug/fail_function//retval: + + specifies the "error" return value to inject to the given + function for given function. This will be created when + user specifies new injection entry. + +Boot option +^^^^^^^^^^^ + +In order to inject faults while debugfs is not available (early boot time), +use the boot option:: + + failslab= + fail_page_alloc= + fail_make_request= + fail_futex= + mmc_core.fail_request=,,, + +proc entries +^^^^^^^^^^^^ + +- /proc//fail-nth, + /proc/self/task//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 + that the fault setup with a previous write to this file was injected. + A positive integer N indicates that the fault wasn't yet injected. + Note that this file enables all types of faults (slab, futex, etc). + This setting takes precedence over all other generic debugfs settings + like probability, interval, times, etc. But per-capability settings + (e.g. fail_futex/ignore-private) take precedence over it. + + This feature is intended for systematic testing of faults in a single + system call. See an example below. + +How to add new fault injection capability +----------------------------------------- + +- #include + +- define the fault attributes + + DECLARE_FAULT_ATTR(name); + + Please see the definition of struct fault_attr in fault-inject.h + for details. + +- provide a way to configure fault attributes + +- boot option + + If you need to enable the fault injection capability from boot time, you can + provide boot option to configure it. There is a helper function for it: + + setup_fault_attr(attr, str); + +- debugfs entries + + failslab, fail_page_alloc, and fail_make_request use this way. + Helper functions: + + fault_create_debugfs_attr(name, parent, attr); + +- module parameters + + If the scope of the fault injection capability is limited to a + single kernel module, it is better to provide module parameters to + configure the fault attributes. + +- add a hook to insert failures + + Upon should_fail() returning true, client code should inject a failure: + + should_fail(attr, size); + +Application Examples +-------------------- + +- Inject slab allocation failures into module init/exit code:: + + #!/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 + + faulty_system() + { + bash -c "echo 1 > /proc/self/make-it-fail && exec $*" + } + + if [ $# -eq 0 ] + then + echo "Usage: $0 modulename [ modulename ... ]" + exit 1 + fi + + for m in $* + do + echo inserting $m... + faulty_system modprobe $m + + echo removing $m... + faulty_system modprobe -r $m + done + +------------------------------------------------------------------------------ + +- Inject page allocation failures only for a specific module:: + + #!/bin/bash + + FAILTYPE=fail_page_alloc + module=$1 + + if [ -z $module ] + then + echo "Usage: $0 " + exit 1 + fi + + modprobe $module + + if [ ! -d /sys/module/$module/sections ] + then + echo Module $module is not loaded + exit 1 + fi + + cat /sys/module/$module/sections/.text > /sys/kernel/debug/$FAILTYPE/require-start + cat /sys/module/$module/sections/.data > /sys/kernel/debug/$FAILTYPE/require-end + + echo N > /sys/kernel/debug/$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 + + echo "Injecting errors into the module $module... (interrupt to stop)" + sleep 1000000 + +------------------------------------------------------------------------------ + +- Inject open_ctree error while btrfs mount:: + + #!/bin/bash + + rm -f testfile.img + dd if=/dev/zero of=testfile.img bs=1M seek=1000 count=1 + DEVICE=$(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 [ $? -ne 0 ] + then + echo "SUCCESS!" + else + echo "FAILED!" + umount tmpmnt + fi + + echo > /sys/kernel/debug/$FAILTYPE/inject + + rmdir tmpmnt + losetup -d $DEVICE + rm testfile.img + + +Tool to run command with failslab or fail_page_alloc +---------------------------------------------------- +In order to make it easier to accomplish the tasks mentioned above, we can use +tools/testing/fault-injection/failcmd.sh. Please run a command +"./tools/testing/fault-injection/failcmd.sh --help" for more information and +see the following examples. + +Examples: + +Run a command "make -C tools/testing/selftests/ run_tests" with injecting slab +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:: + + # ./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:: + + # env FAILCMD_TYPE=fail_page_alloc \ + ./tools/testing/fault-injection/failcmd.sh --times=100 \ + -- 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 + #include + #include + #include + #include + #include + #include + #include + #include + #include + + int main() + { + int i, err, res, fail_nth, fds[2]; + char buf[128]; + + system("echo N > /sys/kernel/debug/failslab/ignore-gfp-wait"); + sprintf(buf, "/proc/self/task/%ld/fail-nth", syscall(SYS_gettid)); + fail_nth = open(buf, O_RDWR); + for (i = 1;; i++) { + sprintf(buf, "%d", i); + write(fail_nth, buf, strlen(buf)); + res = socketpair(AF_LOCAL, SOCK_STREAM, 0, fds); + err = errno; + pread(fail_nth, buf, sizeof(buf), 0); + if (res == 0) { + close(fds[0]); + close(fds[1]); + } + printf("%d-th fault %c: res=%d/%d\n", i, atoi(buf) ? 'N' : 'Y', + res, err); + if (atoi(buf)) + 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 diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt deleted file mode 100644 index a17517a083c3..000000000000 --- a/Documentation/fault-injection/fault-injection.txt +++ /dev/null @@ -1,435 +0,0 @@ -Fault injection capabilities infrastructure -=========================================== - -See also drivers/md/md-faulty.c and "every_nth" module option for scsi_debug. - - -Available fault injection capabilities --------------------------------------- - -o failslab - - injects slab allocation failures. (kmalloc(), kmem_cache_alloc(), ...) - -o fail_page_alloc - - injects page allocation failures. (alloc_pages(), get_free_pages(), ...) - -o fail_futex - - injects futex deadlock and uaddr fault errors. - -o fail_make_request - - injects disk IO errors on devices permitted by setting - /sys/block//make-it-fail or - /sys/block///make-it-fail. (generic_make_request()) - -o 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 - - 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 - - inject NVMe status code and retry flag on devices permitted by setting - debugfs entries under /sys/kernel/debug/nvme*/fault_inject. The default - status code is NVME_SC_INVALID_OPCODE with no retry. The status code and - retry flag can be set via the debugfs. - - -Configure fault-injection capabilities behavior ------------------------------------------------ - -o 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: - - Note that one-failure-per-hundred is a very high error rate - for some testcases. Consider setting probability=100 and configure - /sys/kernel/debug/fail*/interval for such testcases. - -- /sys/kernel/debug/fail*/interval: - - specifies the interval between failures, for calls to - should_fail() that pass all the other tests. - - Note that if you enable this, by setting interval>1, you will - probably want to set probability=100. - -- /sys/kernel/debug/fail*/times: - - specifies how many times failures may happen at most. - A value of -1 means "no limit". - -- /sys/kernel/debug/fail*/space: - - specifies an initial resource "budget", decremented by "size" - on each call to should_fail(,size). Failure injection is - suppressed until "space" reaches zero. - -- /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 - to debug the problems revealed by fault injection. - -- /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//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: - - specifies the range of virtual addresses tested during - stacktrace walking. Failure is injected only if some caller - in the walked stacktrace lies within the required range, and - none lies within the rejected range. - Default required range is [0,ULONG_MAX) (whole of virtual address space). - Default rejected range is [0,0). - -- /sys/kernel/debug/fail*/stacktrace-depth: - - specifies the maximum stacktrace depth walked during search - for a caller within [require-start,require-end) OR - [reject-start,reject-end). - -- /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/failslab/ignore-gfp-wait: -- /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_page_alloc/min-order: - - specifies the minimum page allocation order to be injected - failures. - -- /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 ('') - injection list is cleared. - -- /sys/kernel/debug/fail_function/injectable: - - (read only) shows error injectable functions and what type of - error values can be specified. The error type will be one of - below; - - NULL: retval must be 0. - - ERRNO: retval must be -1 to -MAX_ERRNO (-4096). - - ERR_NULL: retval must be 0 or -1 to -MAX_ERRNO (-4096). - -- /sys/kernel/debug/fail_function//retval: - - specifies the "error" return value to inject to the given - function for given function. This will be created when - user specifies new injection entry. - -o Boot option - -In order to inject faults while debugfs is not available (early boot time), -use the boot option: - - failslab= - fail_page_alloc= - fail_make_request= - fail_futex= - mmc_core.fail_request=,,, - -o proc entries - -- /proc//fail-nth: -- /proc/self/task//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 - that the fault setup with a previous write to this file was injected. - A positive integer N indicates that the fault wasn't yet injected. - Note that this file enables all types of faults (slab, futex, etc). - This setting takes precedence over all other generic debugfs settings - like probability, interval, times, etc. But per-capability settings - (e.g. fail_futex/ignore-private) take precedence over it. - - This feature is intended for systematic testing of faults in a single - system call. See an example below. - -How to add new fault injection capability ------------------------------------------ - -o #include - -o 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 - -- boot option - - If you need to enable the fault injection capability from boot time, you can - provide boot option to configure it. There is a helper function for it: - - setup_fault_attr(attr, str); - -- debugfs entries - - failslab, fail_page_alloc, and fail_make_request use this way. - Helper functions: - - fault_create_debugfs_attr(name, parent, attr); - -- module parameters - - If the scope of the fault injection capability is limited to a - single kernel module, it is better to provide module parameters to - configure the fault attributes. - -o add a hook to insert failures - - 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 - -#!/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 - -faulty_system() -{ - bash -c "echo 1 > /proc/self/make-it-fail && exec $*" -} - -if [ $# -eq 0 ] -then - echo "Usage: $0 modulename [ modulename ... ]" - exit 1 -fi - -for m in $* -do - echo inserting $m... - faulty_system modprobe $m - - echo removing $m... - faulty_system modprobe -r $m -done - ------------------------------------------------------------------------------- - -o Inject page allocation failures only for a specific module - -#!/bin/bash - -FAILTYPE=fail_page_alloc -module=$1 - -if [ -z $module ] -then - echo "Usage: $0 " - exit 1 -fi - -modprobe $module - -if [ ! -d /sys/module/$module/sections ] -then - echo Module $module is not loaded - exit 1 -fi - -cat /sys/module/$module/sections/.text > /sys/kernel/debug/$FAILTYPE/require-start -cat /sys/module/$module/sections/.data > /sys/kernel/debug/$FAILTYPE/require-end - -echo N > /sys/kernel/debug/$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 - -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 [ $? -ne 0 ] -then - echo "SUCCESS!" -else - echo "FAILED!" - umount tmpmnt -fi - -echo > /sys/kernel/debug/$FAILTYPE/inject - -rmdir tmpmnt -losetup -d $DEVICE -rm testfile.img - - -Tool to run command with failslab or fail_page_alloc ----------------------------------------------------- -In order to make it easier to accomplish the tasks mentioned above, we can use -tools/testing/fault-injection/failcmd.sh. Please run a command -"./tools/testing/fault-injection/failcmd.sh --help" for more information and -see the following examples. - -Examples: - -Run a command "make -C tools/testing/selftests/ run_tests" with injecting slab -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. - - # ./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. - - # env FAILCMD_TYPE=fail_page_alloc \ - ./tools/testing/fault-injection/failcmd.sh --times=100 \ - -- 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 -#include -#include -#include -#include -#include -#include -#include -#include -#include - -int main() -{ - int i, err, res, fail_nth, fds[2]; - char buf[128]; - - system("echo N > /sys/kernel/debug/failslab/ignore-gfp-wait"); - sprintf(buf, "/proc/self/task/%ld/fail-nth", syscall(SYS_gettid)); - fail_nth = open(buf, O_RDWR); - for (i = 1;; i++) { - sprintf(buf, "%d", i); - write(fail_nth, buf, strlen(buf)); - res = socketpair(AF_LOCAL, SOCK_STREAM, 0, fds); - err = errno; - pread(fail_nth, buf, sizeof(buf), 0); - if (res == 0) { - close(fds[0]); - close(fds[1]); - } - printf("%d-th fault %c: res=%d/%d\n", i, atoi(buf) ? 'N' : 'Y', - res, err); - if (atoi(buf)) - 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 diff --git a/Documentation/fault-injection/index.rst b/Documentation/fault-injection/index.rst new file mode 100644 index 000000000000..92b5639ed07a --- /dev/null +++ b/Documentation/fault-injection/index.rst @@ -0,0 +1,20 @@ +:orphan: + +=============== +fault-injection +=============== + +.. toctree:: + :maxdepth: 1 + + fault-injection + notifier-error-inject + nvme-fault-injection + provoke-crashes + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/fault-injection/notifier-error-inject.rst b/Documentation/fault-injection/notifier-error-inject.rst new file mode 100644 index 000000000000..1668b6e48d3a --- /dev/null +++ b/Documentation/fault-injection/notifier-error-inject.rst @@ -0,0 +1,98 @@ +Notifier error injection +======================== + +Notifier error injection 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 which is rarely executed. There are kernel +modules that can be used to test the following notifiers. + + * PM notifier + * Memory hotplug notifier + * powerpc pSeries reconfig notifier + * Netdevice notifier + +PM notifier error injection module +---------------------------------- +This feature is controlled through debugfs interface + + /sys/kernel/debug/notifier-error-inject/pm/actions//error + +Possible PM notifier events to be failed are: + + * PM_HIBERNATION_PREPARE + * PM_SUSPEND_PREPARE + * PM_RESTORE_PREPARE + +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 + +Memory hotplug notifier error injection module +---------------------------------------------- +This feature is controlled through debugfs interface + + /sys/kernel/debug/notifier-error-inject/memory/actions//error + +Possible memory notifier events to be failed are: + + * MEM_GOING_ONLINE + * MEM_GOING_OFFLINE + +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 + +powerpc pSeries reconfig notifier error injection module +-------------------------------------------------------- +This feature is controlled through debugfs interface + + /sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions//error + +Possible pSeries reconfig notifier events to be failed are: + + * PSERIES_RECONFIG_ADD + * PSERIES_RECONFIG_REMOVE + * PSERIES_DRCONF_MEM_ADD + * PSERIES_DRCONF_MEM_REMOVE + +Netdevice notifier error injection module +---------------------------------------------- +This feature is controlled through debugfs interface + + /sys/kernel/debug/notifier-error-inject/netdev/actions//error + +Netdevice notifier events which can be failed are: + + * NETDEV_REGISTER + * NETDEV_CHANGEMTU + * NETDEV_CHANGENAME + * NETDEV_PRE_UP + * NETDEV_PRE_TYPE_CHANGE + * NETDEV_POST_INIT + * NETDEV_PRECHANGEMTU + * NETDEV_PRECHANGEUPPER + * NETDEV_CHANGEUPPER + +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 + +For more usage examples +----------------------- +There are tools/testing/selftests using the notifier error injection features +for CPU and memory notifiers. + + * tools/testing/selftests/cpu-hotplug/on-off-test.sh + * tools/testing/selftests/memory-hotplug/on-off-test.sh + +These scripts first do simple online and offline tests and then do fault +injection tests if notifier error injection module is available. diff --git a/Documentation/fault-injection/notifier-error-inject.txt b/Documentation/fault-injection/notifier-error-inject.txt deleted file mode 100644 index e861d761de24..000000000000 --- a/Documentation/fault-injection/notifier-error-inject.txt +++ /dev/null @@ -1,94 +0,0 @@ -Notifier error injection -======================== - -Notifier error injection 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 which is rarely executed. There are kernel -modules that can be used to test the following notifiers. - - * PM notifier - * Memory hotplug notifier - * powerpc pSeries reconfig notifier - * Netdevice notifier - -PM notifier error injection module ----------------------------------- -This feature is controlled through debugfs interface -/sys/kernel/debug/notifier-error-inject/pm/actions//error - -Possible PM notifier events to be failed are: - - * PM_HIBERNATION_PREPARE - * PM_SUSPEND_PREPARE - * PM_RESTORE_PREPARE - -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 - -Memory hotplug notifier error injection module ----------------------------------------------- -This feature is controlled through debugfs interface -/sys/kernel/debug/notifier-error-inject/memory/actions//error - -Possible memory notifier events to be failed are: - - * MEM_GOING_ONLINE - * MEM_GOING_OFFLINE - -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 - -powerpc pSeries reconfig notifier error injection module --------------------------------------------------------- -This feature is controlled through debugfs interface -/sys/kernel/debug/notifier-error-inject/pSeries-reconfig/actions//error - -Possible pSeries reconfig notifier events to be failed are: - - * PSERIES_RECONFIG_ADD - * PSERIES_RECONFIG_REMOVE - * PSERIES_DRCONF_MEM_ADD - * PSERIES_DRCONF_MEM_REMOVE - -Netdevice notifier error injection module ----------------------------------------------- -This feature is controlled through debugfs interface -/sys/kernel/debug/notifier-error-inject/netdev/actions//error - -Netdevice notifier events which can be failed are: - - * NETDEV_REGISTER - * NETDEV_CHANGEMTU - * NETDEV_CHANGENAME - * NETDEV_PRE_UP - * NETDEV_PRE_TYPE_CHANGE - * NETDEV_POST_INIT - * NETDEV_PRECHANGEMTU - * NETDEV_PRECHANGEUPPER - * NETDEV_CHANGEUPPER - -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 - -For more usage examples ------------------------ -There are tools/testing/selftests using the notifier error injection features -for CPU and memory notifiers. - - * tools/testing/selftests/cpu-hotplug/on-off-test.sh - * tools/testing/selftests/memory-hotplug/on-off-test.sh - -These scripts first do simple online and offline tests and then do fault -injection tests if notifier error injection module is available. diff --git a/Documentation/fault-injection/nvme-fault-injection.rst b/Documentation/fault-injection/nvme-fault-injection.rst new file mode 100644 index 000000000000..bbb1bf3e8650 --- /dev/null +++ b/Documentation/fault-injection/nvme-fault-injection.rst @@ -0,0 +1,120 @@ +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: + + 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 + + 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: + + 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 + + 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 diff --git a/Documentation/fault-injection/nvme-fault-injection.txt b/Documentation/fault-injection/nvme-fault-injection.txt deleted file mode 100644 index 8fbf3bf60b62..000000000000 --- a/Documentation/fault-injection/nvme-fault-injection.txt +++ /dev/null @@ -1,116 +0,0 @@ -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: - - 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 - -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: - - 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 - -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 diff --git a/Documentation/fault-injection/provoke-crashes.rst b/Documentation/fault-injection/provoke-crashes.rst new file mode 100644 index 000000000000..9279a3e12278 --- /dev/null +++ b/Documentation/fault-injection/provoke-crashes.rst @@ -0,0 +1,48 @@ +=============== +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 +/provoke-crash/. 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. diff --git a/Documentation/fault-injection/provoke-crashes.txt b/Documentation/fault-injection/provoke-crashes.txt deleted file mode 100644 index 7a9d3d81525b..000000000000 --- a/Documentation/fault-injection/provoke-crashes.txt +++ /dev/null @@ -1,38 +0,0 @@ -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 -/provoke-crash/. 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. -- cgit v1.2.3