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-rw-r--r--Documentation/fault-injection/fault-injection.txt70
1 files changed, 35 insertions, 35 deletions
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index 4bc374a14345..079305640790 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -29,16 +29,16 @@ o debugfs entries
29fault-inject-debugfs kernel module provides some debugfs entries for runtime 29fault-inject-debugfs kernel module provides some debugfs entries for runtime
30configuration of fault-injection capabilities. 30configuration of fault-injection capabilities.
31 31
32- /debug/fail*/probability: 32- /sys/kernel/debug/fail*/probability:
33 33
34 likelihood of failure injection, in percent. 34 likelihood of failure injection, in percent.
35 Format: <percent> 35 Format: <percent>
36 36
37 Note that one-failure-per-hundred is a very high error rate 37 Note that one-failure-per-hundred is a very high error rate
38 for some testcases. Consider setting probability=100 and configure 38 for some testcases. Consider setting probability=100 and configure
39 /debug/fail*/interval for such testcases. 39 /sys/kernel/debug/fail*/interval for such testcases.
40 40
41- /debug/fail*/interval: 41- /sys/kernel/debug/fail*/interval:
42 42
43 specifies the interval between failures, for calls to 43 specifies the interval between failures, for calls to
44 should_fail() that pass all the other tests. 44 should_fail() that pass all the other tests.
@@ -46,18 +46,18 @@ configuration of fault-injection capabilities.
46 Note that if you enable this, by setting interval>1, you will 46 Note that if you enable this, by setting interval>1, you will
47 probably want to set probability=100. 47 probably want to set probability=100.
48 48
49- /debug/fail*/times: 49- /sys/kernel/debug/fail*/times:
50 50
51 specifies how many times failures may happen at most. 51 specifies how many times failures may happen at most.
52 A value of -1 means "no limit". 52 A value of -1 means "no limit".
53 53
54- /debug/fail*/space: 54- /sys/kernel/debug/fail*/space:
55 55
56 specifies an initial resource "budget", decremented by "size" 56 specifies an initial resource "budget", decremented by "size"
57 on each call to should_fail(,size). Failure injection is 57 on each call to should_fail(,size). Failure injection is
58 suppressed until "space" reaches zero. 58 suppressed until "space" reaches zero.
59 59
60- /debug/fail*/verbose 60- /sys/kernel/debug/fail*/verbose
61 61
62 Format: { 0 | 1 | 2 } 62 Format: { 0 | 1 | 2 }
63 specifies the verbosity of the messages when failure is 63 specifies the verbosity of the messages when failure is
@@ -65,17 +65,17 @@ configuration of fault-injection capabilities.
65 log line per failure; '2' will print a call trace too -- useful 65 log line per failure; '2' will print a call trace too -- useful
66 to debug the problems revealed by fault injection. 66 to debug the problems revealed by fault injection.
67 67
68- /debug/fail*/task-filter: 68- /sys/kernel/debug/fail*/task-filter:
69 69
70 Format: { 'Y' | 'N' } 70 Format: { 'Y' | 'N' }
71 A value of 'N' disables filtering by process (default). 71 A value of 'N' disables filtering by process (default).
72 Any positive value limits failures to only processes indicated by 72 Any positive value limits failures to only processes indicated by
73 /proc/<pid>/make-it-fail==1. 73 /proc/<pid>/make-it-fail==1.
74 74
75- /debug/fail*/require-start: 75- /sys/kernel/debug/fail*/require-start:
76- /debug/fail*/require-end: 76- /sys/kernel/debug/fail*/require-end:
77- /debug/fail*/reject-start: 77- /sys/kernel/debug/fail*/reject-start:
78- /debug/fail*/reject-end: 78- /sys/kernel/debug/fail*/reject-end:
79 79
80 specifies the range of virtual addresses tested during 80 specifies the range of virtual addresses tested during
81 stacktrace walking. Failure is injected only if some caller 81 stacktrace walking. Failure is injected only if some caller
@@ -84,26 +84,26 @@ configuration of fault-injection capabilities.
84 Default required range is [0,ULONG_MAX) (whole of virtual address space). 84 Default required range is [0,ULONG_MAX) (whole of virtual address space).
85 Default rejected range is [0,0). 85 Default rejected range is [0,0).
86 86
87- /debug/fail*/stacktrace-depth: 87- /sys/kernel/debug/fail*/stacktrace-depth:
88 88
89 specifies the maximum stacktrace depth walked during search 89 specifies the maximum stacktrace depth walked during search
90 for a caller within [require-start,require-end) OR 90 for a caller within [require-start,require-end) OR
91 [reject-start,reject-end). 91 [reject-start,reject-end).
92 92
93- /debug/fail_page_alloc/ignore-gfp-highmem: 93- /sys/kernel/debug/fail_page_alloc/ignore-gfp-highmem:
94 94
95 Format: { 'Y' | 'N' } 95 Format: { 'Y' | 'N' }
96 default is 'N', setting it to 'Y' won't inject failures into 96 default is 'N', setting it to 'Y' won't inject failures into
97 highmem/user allocations. 97 highmem/user allocations.
98 98
99- /debug/failslab/ignore-gfp-wait: 99- /sys/kernel/debug/failslab/ignore-gfp-wait:
100- /debug/fail_page_alloc/ignore-gfp-wait: 100- /sys/kernel/debug/fail_page_alloc/ignore-gfp-wait:
101 101
102 Format: { 'Y' | 'N' } 102 Format: { 'Y' | 'N' }
103 default is 'N', setting it to 'Y' will inject failures 103 default is 'N', setting it to 'Y' will inject failures
104 only into non-sleep allocations (GFP_ATOMIC allocations). 104 only into non-sleep allocations (GFP_ATOMIC allocations).
105 105
106- /debug/fail_page_alloc/min-order: 106- /sys/kernel/debug/fail_page_alloc/min-order:
107 107
108 specifies the minimum page allocation order to be injected 108 specifies the minimum page allocation order to be injected
109 failures. 109 failures.
@@ -166,13 +166,13 @@ o Inject slab allocation failures into module init/exit code
166#!/bin/bash 166#!/bin/bash
167 167
168FAILTYPE=failslab 168FAILTYPE=failslab
169echo Y > /debug/$FAILTYPE/task-filter 169echo Y > /sys/kernel/debug/$FAILTYPE/task-filter
170echo 10 > /debug/$FAILTYPE/probability 170echo 10 > /sys/kernel/debug/$FAILTYPE/probability
171echo 100 > /debug/$FAILTYPE/interval 171echo 100 > /sys/kernel/debug/$FAILTYPE/interval
172echo -1 > /debug/$FAILTYPE/times 172echo -1 > /sys/kernel/debug/$FAILTYPE/times
173echo 0 > /debug/$FAILTYPE/space 173echo 0 > /sys/kernel/debug/$FAILTYPE/space
174echo 2 > /debug/$FAILTYPE/verbose 174echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
175echo 1 > /debug/$FAILTYPE/ignore-gfp-wait 175echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
176 176
177faulty_system() 177faulty_system()
178{ 178{
@@ -217,20 +217,20 @@ then
217 exit 1 217 exit 1
218fi 218fi
219 219
220cat /sys/module/$module/sections/.text > /debug/$FAILTYPE/require-start 220cat /sys/module/$module/sections/.text > /sys/kernel/debug/$FAILTYPE/require-start
221cat /sys/module/$module/sections/.data > /debug/$FAILTYPE/require-end 221cat /sys/module/$module/sections/.data > /sys/kernel/debug/$FAILTYPE/require-end
222 222
223echo N > /debug/$FAILTYPE/task-filter 223echo N > /sys/kernel/debug/$FAILTYPE/task-filter
224echo 10 > /debug/$FAILTYPE/probability 224echo 10 > /sys/kernel/debug/$FAILTYPE/probability
225echo 100 > /debug/$FAILTYPE/interval 225echo 100 > /sys/kernel/debug/$FAILTYPE/interval
226echo -1 > /debug/$FAILTYPE/times 226echo -1 > /sys/kernel/debug/$FAILTYPE/times
227echo 0 > /debug/$FAILTYPE/space 227echo 0 > /sys/kernel/debug/$FAILTYPE/space
228echo 2 > /debug/$FAILTYPE/verbose 228echo 2 > /sys/kernel/debug/$FAILTYPE/verbose
229echo 1 > /debug/$FAILTYPE/ignore-gfp-wait 229echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-wait
230echo 1 > /debug/$FAILTYPE/ignore-gfp-highmem 230echo 1 > /sys/kernel/debug/$FAILTYPE/ignore-gfp-highmem
231echo 10 > /debug/$FAILTYPE/stacktrace-depth 231echo 10 > /sys/kernel/debug/$FAILTYPE/stacktrace-depth
232 232
233trap "echo 0 > /debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT 233trap "echo 0 > /sys/kernel/debug/$FAILTYPE/probability" SIGINT SIGTERM EXIT
234 234
235echo "Injecting errors into the module $module... (interrupt to stop)" 235echo "Injecting errors into the module $module... (interrupt to stop)"
236sleep 1000000 236sleep 1000000