Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 911916c5 authored by Liam Mark's avatar Liam Mark
Browse files

Revert "ashmem: switch to ->read_iter" 



This reverts commit 8a2af064 ("ashmem: switch to ->read_iter")

This change resulted in ashmem file descriptors now getting labeled as
system_server_tmpfs instead of ashmem_device.

SELinux is rejecting access to file descriptors labeled as
system_server_tmpfs and this is causing the battery settings app to crash.

It does not look feasible to get SELinux to accept system_server_tmpfs
labeled file descriptors as it is used too broadly.
So for now revert this change until we can find a clean way to fix this.

Change-Id: I5710c37f1204a296736b0e22bdaf12fe292d9c62
Signed-off-by: default avatarLiam Mark <lmark@codeaurora.org>
parent 3fd2e0f2

drivers/staging/android/ashmem.c

+21 −8
Original line number Diff line number Diff line
@@ -294,9 +294,19 @@ static int ashmem_release(struct inode *ignored, struct file *file) 
	return 0;

}



static ssize_t ashmem_read_iter(struct kiocb *iocb, struct iov_iter *iter)

/**

 * ashmem_read() - Reads a set of bytes from an Ashmem-enabled file

 * @file:	   The associated backing file.

 * @buf:	   The buffer of data being written to

 * @len:	   The number of bytes being read

 * @pos:	   The position of the first byte to read.

 *

 * Return: 0 if successful, or another return code if not.

 */

static ssize_t ashmem_read(struct file *file, char __user *buf,

			   size_t len, loff_t *pos)

{

	struct ashmem_area *asma = iocb->ki_filp->private_data;

	struct ashmem_area *asma = file->private_data;

	int ret = 0;



	mutex_lock(&ashmem_mutex);
@@ -310,17 +320,20 @@ static ssize_t ashmem_read_iter(struct kiocb *iocb, struct iov_iter *iter) 
		goto out_unlock;

	}



	mutex_unlock(&ashmem_mutex);



	/*

	 * asma and asma->file are used outside the lock here.  We assume

	 * once asma->file is set it will never be changed, and will not

	 * be destroyed until all references to the file are dropped and

	 * ashmem_release is called.

	 */

	mutex_unlock(&ashmem_mutex);

	ret = vfs_iter_read(asma->file, iter, &iocb->ki_pos, 0);

	mutex_lock(&ashmem_mutex);

	if (ret > 0)

		asma->file->f_pos = iocb->ki_pos;

	ret = __vfs_read(asma->file, buf, len, pos);

	if (ret >= 0)

		/** Update backing file pos, since f_ops->read() doesn't */

		asma->file->f_pos = *pos;

	return ret;



out_unlock:

	mutex_unlock(&ashmem_mutex);

	return ret;
@@ -815,7 +828,7 @@ static const struct file_operations ashmem_fops = { 
	.owner = THIS_MODULE,

	.open = ashmem_open,

	.release = ashmem_release,

	.read_iter = ashmem_read_iter,

	.read = ashmem_read,

	.llseek = ashmem_llseek,

	.mmap = ashmem_mmap,

	.unlocked_ioctl = ashmem_ioctl,