proc: Update get proc_pid_cmdline() to use mm.h helpers

Re-factor proc_pid_cmdline() to use get_cmdline() helper
from mm.h.

Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Richard Guy Briggs <rgb@redhat.com>

Signed-off-by: William Roberts <wroberts@tresys.com>
Acked-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 2 insertions, 34 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 03c8d747be48..cfd178dc76b2 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -200,41 +200,9 @@ static int proc_root_link(struct dentry *dentry, struct path *path)
         return result;
 }
 
-static int proc_pid_cmdline(struct task_struct *task, char * buffer)
+static int proc_pid_cmdline(struct task_struct *task, char *buffer)
 {
-        int res = 0;
-        unsigned int len;
-        struct mm_struct *mm = get_task_mm(task);
-        if (!mm)
-                goto out;
-        if (!mm->arg_end)
-                goto out_mm;    /* Shh! No looking before we're done */
-
-        len = mm->arg_end - mm->arg_start;
- 
-        if (len > PAGE_SIZE)
-                len = PAGE_SIZE;
- 
-        res = access_process_vm(task, mm->arg_start, buffer, len, 0);
-
-        // If the nul at the end of args has been overwritten, then
-        // assume application is using setproctitle(3).
-        if (res > 0 && buffer[res-1] != '\0' && len < PAGE_SIZE) {
-                len = strnlen(buffer, res);
-                if (len < res) {
-                    res = len;
-                } else {
-                        len = mm->env_end - mm->env_start;
-                        if (len > PAGE_SIZE - res)
-                                len = PAGE_SIZE - res;
-                        res += access_process_vm(task, mm->env_start, buffer+res, len, 0);
-                        res = strnlen(buffer, res);
-                }
-        }
-out_mm:
-        mmput(mm);
-out:
-        return res;
+        return get_cmdline(task, buffer, PAGE_SIZE);
 }
 
 static int proc_pid_auxv(struct task_struct *task, char *buffer)