[PATCH] fault injection: process filtering for fault-injection capabilities

[linux-2.6-block.git] / fs / proc / base.c

diff --git a/fs/proc/base.c b/fs/proc/base.c
index a3b5074118a751d4e7993d83106f993c9f926500..fd959d5b5a802c0897d586114a0c1fb2878ceec0 100644 (file)
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -853,6 +853,65 @@ static struct file_operations proc_seccomp_operations = {
 };
 #endif /* CONFIG_SECCOMP */
 
+#ifdef CONFIG_FAULT_INJECTION
+static ssize_t proc_fault_inject_read(struct file * file, char __user * buf,
+                                     size_t count, loff_t *ppos)
+{
+       struct task_struct *task = get_proc_task(file->f_dentry->d_inode);
+       char buffer[PROC_NUMBUF];
+       size_t len;
+       int make_it_fail;
+       loff_t __ppos = *ppos;
+
+       if (!task)
+               return -ESRCH;
+       make_it_fail = task->make_it_fail;
+       put_task_struct(task);
+
+       len = snprintf(buffer, sizeof(buffer), "%i\n", make_it_fail);
+       if (__ppos >= len)
+               return 0;
+       if (count > len-__ppos)
+               count = len-__ppos;
+       if (copy_to_user(buf, buffer + __ppos, count))
+               return -EFAULT;
+       *ppos = __ppos + count;
+       return count;
+}
+
+static ssize_t proc_fault_inject_write(struct file * file,
+                       const char __user * buf, size_t count, loff_t *ppos)
+{
+       struct task_struct *task;
+       char buffer[PROC_NUMBUF], *end;
+       int make_it_fail;
+
+       if (!capable(CAP_SYS_RESOURCE))
+               return -EPERM;
+       memset(buffer, 0, sizeof(buffer));
+       if (count > sizeof(buffer) - 1)
+               count = sizeof(buffer) - 1;
+       if (copy_from_user(buffer, buf, count))
+               return -EFAULT;
+       make_it_fail = simple_strtol(buffer, &end, 0);
+       if (*end == '\n')
+               end++;
+       task = get_proc_task(file->f_dentry->d_inode);
+       if (!task)
+               return -ESRCH;
+       task->make_it_fail = make_it_fail;
+       put_task_struct(task);
+       if (end - buffer == 0)
+               return -EIO;
+       return end - buffer;
+}
+
+static struct file_operations proc_fault_inject_operations = {
+       .read           = proc_fault_inject_read,
+       .write          = proc_fault_inject_write,
+};
+#endif
+
 static void *proc_pid_follow_link(struct dentry *dentry, struct nameidata *nd)
 {
        struct inode *inode = dentry->d_inode;
@@ -1793,6 +1852,9 @@ static struct pid_entry tgid_base_stuff[] = {
 #ifdef CONFIG_AUDITSYSCALL
        REG("loginuid",   S_IWUSR|S_IRUGO, loginuid),
 #endif
+#ifdef CONFIG_FAULT_INJECTION
+       REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
+#endif
 };
 
 static int proc_tgid_base_readdir(struct file * filp,
@@ -2068,6 +2130,9 @@ static struct pid_entry tid_base_stuff[] = {
 #ifdef CONFIG_AUDITSYSCALL
        REG("loginuid",  S_IWUSR|S_IRUGO, loginuid),
 #endif
+#ifdef CONFIG_FAULT_INJECTION
+       REG("make-it-fail", S_IRUGO|S_IWUSR, fault_inject),
+#endif
 };
 
 static int proc_tid_base_readdir(struct file * filp,