diff options
Diffstat (limited to 'fs/proc/base.c')
| -rw-r--r-- | fs/proc/base.c | 41 |
1 files changed, 17 insertions, 24 deletions
diff --git a/fs/proc/base.c b/fs/proc/base.c index 88b773f318cd..719c2e943ea1 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -1360,20 +1360,19 @@ static ssize_t proc_fail_nth_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) { struct task_struct *task; - int err, n; + int err; + unsigned int n; + + err = kstrtouint_from_user(buf, count, 0, &n); + if (err) + return err; task = get_proc_task(file_inode(file)); if (!task) return -ESRCH; + WRITE_ONCE(task->fail_nth, n); put_task_struct(task); - if (task != current) - return -EPERM; - err = kstrtoint_from_user(buf, count, 10, &n); - if (err) - return err; - if (n < 0 || n == INT_MAX) - return -EINVAL; - current->fail_nth = n + 1; + return count; } @@ -1381,21 +1380,18 @@ 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) return -ESRCH; + len = snprintf(numbuf, sizeof(numbuf), "%u\n", + READ_ONCE(task->fail_nth)); + len = simple_read_from_buffer(buf, count, ppos, numbuf, len); 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; + + return len; } static const struct file_operations proc_fail_nth_operations = { @@ -2966,6 +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), @@ -3358,11 +3355,7 @@ static const struct pid_entry tid_base_stuff[] = { #endif #ifdef CONFIG_FAULT_INJECTION REG("make-it-fail", S_IRUGO|S_IWUSR, proc_fault_inject_operations), - /* - * Operations on the file check that the task is current, - * so we create it with 0666 to support testing under unprivileged user. - */ - REG("fail-nth", 0666, proc_fail_nth_operations), + REG("fail-nth", 0644, proc_fail_nth_operations), #endif #ifdef CONFIG_TASK_IO_ACCOUNTING ONE("io", S_IRUSR, proc_tid_io_accounting), |