ARM: tegra: Enable PLLP bypass during Tegra124 LP1

[sagit-ice-cold/kernel_xiaomi_msm8998.git] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 42cf8dd..1e7263b 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -38,6 +38,12 @@ unsigned int pipe_max_size = 1048576;
  */
 unsigned int pipe_min_size = PAGE_SIZE;
 
+/* Maximum allocatable pages per user. Hard limit is unset by default, soft
+ * matches default values.
+ */
+unsigned long pipe_user_pages_hard;
+unsigned long pipe_user_pages_soft = PIPE_DEF_BUFFERS * INR_OPEN_CUR;
+
 /*
  * We use a start+len construction, which provides full use of the 
  * allocated memory.
@@ -583,20 +589,52 @@ pipe_fasync(int fd, struct file *filp, int on)
        return retval;
 }
 
+static void account_pipe_buffers(struct pipe_inode_info *pipe,
+                                 unsigned long old, unsigned long new)
+{
+       atomic_long_add(new - old, &pipe->user->pipe_bufs);
+}
+
+static bool too_many_pipe_buffers_soft(struct user_struct *user)
+{
+       return pipe_user_pages_soft &&
+              atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_soft;
+}
+
+static bool too_many_pipe_buffers_hard(struct user_struct *user)
+{
+       return pipe_user_pages_hard &&
+              atomic_long_read(&user->pipe_bufs) >= pipe_user_pages_hard;
+}
+
 struct pipe_inode_info *alloc_pipe_info(void)
 {
        struct pipe_inode_info *pipe;
 
        pipe = kzalloc(sizeof(struct pipe_inode_info), GFP_KERNEL);
        if (pipe) {
-               pipe->bufs = kzalloc(sizeof(struct pipe_buffer) * PIPE_DEF_BUFFERS, GFP_KERNEL);
+               unsigned long pipe_bufs = PIPE_DEF_BUFFERS;
+               struct user_struct *user = get_current_user();
+
+               if (pipe_bufs * PAGE_SIZE > pipe_max_size && !capable(CAP_SYS_RESOURCE))
+                       pipe_bufs = pipe_max_size >> PAGE_SHIFT;
+
+               if (!too_many_pipe_buffers_hard(user)) {
+                       if (too_many_pipe_buffers_soft(user))
+                               pipe_bufs = 1;
+                       pipe->bufs = kzalloc(sizeof(struct pipe_buffer) * pipe_bufs, GFP_KERNEL);
+               }
+
                if (pipe->bufs) {
                        init_waitqueue_head(&pipe->wait);
                        pipe->r_counter = pipe->w_counter = 1;
-                       pipe->buffers = PIPE_DEF_BUFFERS;
+                       pipe->buffers = pipe_bufs;
+                       pipe->user = user;
+                       account_pipe_buffers(pipe, 0, pipe_bufs);
                        mutex_init(&pipe->mutex);
                        return pipe;
                }
+               free_uid(user);
                kfree(pipe);
        }
 
@@ -607,6 +645,8 @@ void free_pipe_info(struct pipe_inode_info *pipe)
 {
        int i;
 
+       account_pipe_buffers(pipe, pipe->buffers, 0);
+       free_uid(pipe->user);
        for (i = 0; i < pipe->buffers; i++) {
                struct pipe_buffer *buf = pipe->bufs + i;
                if (buf->ops)
@@ -964,6 +1004,9 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
 {
        struct pipe_buffer *bufs;
 
+       if (!nr_pages)
+               return -EINVAL;
+
        /*
         * We can shrink the pipe, if arg >= pipe->nrbufs. Since we don't
         * expect a lot of shrink+grow operations, just free and allocate
@@ -998,6 +1041,7 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
                        memcpy(bufs + head, pipe->bufs, tail * sizeof(struct pipe_buffer));
        }
 
+       account_pipe_buffers(pipe, pipe->buffers, nr_pages);
        pipe->curbuf = 0;
        kfree(pipe->bufs);
        pipe->bufs = bufs;
@@ -1007,13 +1051,19 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned long nr_pages)
 
 /*
  * Currently we rely on the pipe array holding a power-of-2 number
- * of pages.
+ * of pages. Returns 0 on error.
  */
 static inline unsigned int round_pipe_size(unsigned int size)
 {
        unsigned long nr_pages;
 
+       if (size < pipe_min_size)
+               size = pipe_min_size;
+
        nr_pages = (size + PAGE_SIZE - 1) >> PAGE_SHIFT;
+       if (nr_pages == 0)
+               return 0;
+
        return roundup_pow_of_two(nr_pages) << PAGE_SHIFT;
 }
 
@@ -1024,13 +1074,18 @@ static inline unsigned int round_pipe_size(unsigned int size)
 int pipe_proc_fn(struct ctl_table *table, int write, void __user *buf,
                 size_t *lenp, loff_t *ppos)
 {
+       unsigned int rounded_pipe_max_size;
        int ret;
 
        ret = proc_dointvec_minmax(table, write, buf, lenp, ppos);
        if (ret < 0 || !write)
                return ret;
 
-       pipe_max_size = round_pipe_size(pipe_max_size);
+       rounded_pipe_max_size = round_pipe_size(pipe_max_size);
+       if (rounded_pipe_max_size == 0)
+               return -EINVAL;
+
+       pipe_max_size = rounded_pipe_max_size;
        return ret;
 }
 
@@ -1069,6 +1124,11 @@ long pipe_fcntl(struct file *file, unsigned int cmd, unsigned long arg)
                if (!capable(CAP_SYS_RESOURCE) && size > pipe_max_size) {
                        ret = -EPERM;
                        goto out;
+               } else if ((too_many_pipe_buffers_hard(pipe->user) ||
+                           too_many_pipe_buffers_soft(pipe->user)) &&
+                          !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN)) {
+                       ret = -EPERM;
+                       goto out;
                }
                ret = pipe_set_size(pipe, nr_pages);
                break;