net: show cmdline in /proc/net/{tcp udp tcp6 udp6}

Get process's cmdline from a sock's corresponding inode pointer,
 so that cmdline can't be used by Android active-standby app
to find the corresponding package name.

Bug 1185001

Change-Id: Idc8651e4bb85b8a152dfade9689a719f7d72687d
Signed-off-by: Chun Xu <chunx@nvidia.com>
Reviewed-on: http://git-master/r/253458
(cherry picked from commit 5dcfe4f561bd8d1767e0938dfd7565b2b7718478)
Reviewed-on: http://git-master/r/260013
Reviewed-by: Simone Willett <swillett@nvidia.com>
Tested-by: Simone Willett <swillett@nvidia.com>

3 files changed, 46 insertions, 3 deletions

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 0cff4434880d..e92a15091d80 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -9,6 +9,8 @@
  *
  *  Davide Libenzi <davidel@xmailserver.org>
  *
+ * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
+ *
  */
 
 #include <linux/init.h>
@@ -967,7 +969,7 @@ static struct epitem *ep_find(struct eventpoll *ep, struct file *file, int fd)
  * mechanism. It is called by the stored file descriptors when they
  * have events to report.
  */
-static int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *key)
+int ep_poll_callback(wait_queue_t *wait, unsigned mode, int sync, void *key)
 {
 	int pwake = 0;
 	unsigned long flags;
@@ -1064,6 +1066,7 @@ static void ep_ptable_queue_proc(struct file *file, wait_queue_head_t *whead,
 
 	if (epi->nwait >= 0 && (pwq = kmem_cache_alloc(pwq_cache, GFP_KERNEL))) {
 		init_waitqueue_func_entry(&pwq->wait, ep_poll_callback);
+		pwq->wait.private = get_thread_process(current);
 		pwq->whead = whead;
 		pwq->base = epi;
 		add_wait_queue(whead, &pwq->wait);
@@ -1287,6 +1290,7 @@ static int ep_insert(struct eventpoll *ep, struct epoll_event *event,
 	spin_lock(&tfile->f_lock);
 	list_add_tail(&epi->fllink, &tfile->f_ep_links);
 	spin_unlock(&tfile->f_lock);
+	tfile->f_path.dentry->d_inode->i_private = get_thread_process(current);
 
 	/*
 	 * Add the current item to the RB tree. All RB tree operations are
@@ -1728,6 +1732,35 @@ static void clear_tfile_check_list(void)
 	INIT_LIST_HEAD(&tfile_check_list);
 }
 
+struct task_struct *get_epoll_file_task(struct file *file)
+{
+	struct list_head *lh;
+	struct epitem *epi = NULL;
+	struct eppoll_entry *pwq = NULL;
+	struct task_struct *task = NULL;
+	wait_queue_head_t *whead = NULL;
+	wait_queue_t *wq = NULL;
+
+	lh = &file->f_ep_links;
+	if (!list_empty(lh)) {
+		lh = lh->next;
+		epi = list_entry(lh, struct epitem, fllink);
+		lh = &epi->pwqlist;
+		if (!list_empty(lh)) {
+			lh = lh->next;
+			pwq = list_entry(lh, struct eppoll_entry, llink);
+			lh = &pwq->whead->task_list;
+			if (!list_empty(lh)) {
+				lh = lh->next;
+				wq = list_entry(lh, wait_queue_t, task_list);
+				task = wq->private;
+			}
+		}
+	}
+
+	return task;
+}
+
 /*
  * Open an eventpoll file descriptor.
  */
diff --git a/fs/proc/base.c b/fs/proc/base.c
index 2d00fdde9345..77377014887c 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -45,6 +45,8 @@
  *
  *  Paul Mundt <paul.mundt@nokia.com>:
  *  Overall revision about smaps.
+ *
+ * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
  */
 
 #include <asm/uaccess.h>
@@ -206,7 +208,12 @@ static int proc_root_link(struct dentry *dentry, struct path *path)
 	return result;
 }
 
-static int proc_pid_cmdline(struct task_struct *task, char * buffer)
+struct mm_struct *mm_for_maps(struct task_struct *task)
+{
+	return mm_access(task, PTRACE_MODE_READ);
+}
+
+static int proc_pid_cmdline(struct task_struct *task, char *buffer)
 {
 	int res = 0;
 	unsigned int len;
diff --git a/fs/select.c b/fs/select.c
index 6b14dc7df3a4..0595305eeb0a 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -12,6 +12,8 @@
  *  24 January 2000
  *     Changed sys_poll()/do_poll() to use PAGE_SIZE chunk-based allocation 
  *     of fds to overcome nfds < 16390 descriptors limit (Tigran Aivazian).
+  *
+  * Copyright (c) 2013, NVIDIA CORPORATION.  All rights reserved.
  */
 
 #include <linux/kernel.h>
@@ -204,7 +206,7 @@ static int __pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
 	return default_wake_function(&dummy_wait, mode, sync, key);
 }
 
-static int pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
+int pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
 {
 	struct poll_table_entry *entry;
 
@@ -213,6 +215,7 @@ static int pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
 		return 0;
 	return __pollwake(wait, mode, sync, key);
 }
+EXPORT_SYMBOL(pollwake);
 
 /* Add a new entry */
 static void __pollwait(struct file *filp, wait_queue_head_t *wait_address,