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| author |   Akinobu Mita <akinobu.mita@gmail.com> | 2017-07-14 14:49:54 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2017-07-14 15:05:13 -0700 |
| commit | bfc740938d151001cb1158580796f8f3be3bf0c1 (patch) | |
| tree | 3a0f549da5213fca25afe2ea9a8d4c20b7cc9b99 /fs/proc/base.c | |
| parent | fault-inject: parse as natural 1-based value for fail-nth write interface (diff) | |
| download | wireguard-linux-bfc740938d151001cb1158580796f8f3be3bf0c1.tar.xz wireguard-linux-bfc740938d151001cb1158580796f8f3be3bf0c1.zip | |
fault-inject: make fail-nth read/write interface symmetric
The read interface for fail-nth looks a bit odd. Read from this file
returns "NYYYY..." or "YYYYY..." (this makes me surprise when cat this
file). Because there is no EOF condition. The first character
indicates current->fail_nth is zero or not, and then current->fail_nth
is reset to zero.
Just returning task->fail_nth value is more natural to understand.
Link: http://lkml.kernel.org/r/1491490561-10485-4-git-send-email-akinobu.mita@gmail.com
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
| -rw-r--r-- | fs/proc/base.c | 14 |
1 files changed, 6 insertions, 8 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index c1fdaecb8d23..7d795d28dd02 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1380,7 +1380,8 @@ static ssize_t proc_fail_nth_read(struct file *file, char __user *buf, size_t count, loff_t *ppos) { struct task_struct *task; - int err; + char numbuf[PROC_NUMBUF]; + ssize_t len; task = get_proc_task(file_inode(file)); if (!task) @@ -1388,13 +1389,10 @@ static ssize_t proc_fail_nth_read(struct file *file, char __user *buf, put_task_struct(task); if (task != current) return -EPERM; - if (count < 1) - return -EINVAL; - err = put_user((char)(current->fail_nth ? 'N' : 'Y'), buf); - if (err) - return err; - current->fail_nth = 0; - return 1; + len = snprintf(numbuf, sizeof(numbuf), "%u\n", task->fail_nth); + len = simple_read_from_buffer(buf, count, ppos, numbuf, len); + + return len; } static const struct file_operations proc_fail_nth_operations = { |