fault-inject: add /proc/<pid>/fail-nth

fail-nth interface is only created in /proc/self/task/<current-tid>/. This change also adds it in /proc/<pid>/. This makes shell based tool a bit simpler. $ bash -c "builtin echo 100 > /proc/self/fail-nth && exec ls /" Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Akinobu Mita <[email protected]> Cc: Dmitry Vyukov <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
chewitt · Jul 14, 2017 · 168c42b · 168c42b
1 parent 1203c8e
commit 168c42b
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diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
@@ -136,7 +136,8 @@ use the boot option:
 
 o proc entries
 
-- /proc/self/task/<current-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

diff --git a/fs/proc/base.c b/fs/proc/base.c
@@ -2962,6 +2962,7 @@ static const struct pid_entry tgid_base_stuff[] = {
 #endif
 #ifdef CONFIG_FAULT_INJECTION
 	REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations),
+	REG("fail-nth", 0644, proc_fail_nth_operations),
 #endif
 #ifdef CONFIG_ELF_CORE
 	REG("coredump_filter", S_IRUGO|S_IWUSR, proc_coredump_filter_operations),