From 6809f0087c72d4b3eab3563c4b36bab52a9d8e7c Mon Sep 17 00:00:00 2001 From: Bjorn Bringert Date: Thu, 15 Apr 2010 10:04:01 +0100 Subject: [PATCH 177/696] Implement read(2) in ashmem driver Bug: 2595601 Change-Id: I47c0016f594f9354fb8658ccb26e3d395bcb137b Signed-off-by: Bjorn Bringert --- mm/ashmem.c | 26 ++++++++++++++++++++++++++ 1 files changed, 26 insertions(+), 0 deletions(-) diff --git a/mm/ashmem.c b/mm/ashmem.c index 230810f..04e886e 100644 --- a/mm/ashmem.c +++ b/mm/ashmem.c @@ -211,6 +211,31 @@ static int ashmem_release(struct inode *ignored, struct file *file) return 0; } +static ssize_t ashmem_read(struct file *file, char __user *buf, + size_t len, loff_t *pos) +{ + struct ashmem_area *asma = file->private_data; + int ret = 0; + + mutex_lock(&ashmem_mutex); + + /* If size is not set, or set to 0, always return EOF. */ + if (asma->size == 0) { + goto out; + } + + if (!asma->file) { + ret = -EBADF; + goto out; + } + + ret = asma->file->f_op->read(asma->file, buf, len, pos); + +out: + mutex_unlock(&ashmem_mutex); + return ret; +} + static int ashmem_mmap(struct file *file, struct vm_area_struct *vma) { struct ashmem_area *asma = file->private_data; @@ -604,6 +629,7 @@ static struct file_operations ashmem_fops = { .owner = THIS_MODULE, .open = ashmem_open, .release = ashmem_release, + .read = ashmem_read, .mmap = ashmem_mmap, .unlocked_ioctl = ashmem_ioctl, .compat_ioctl = ashmem_ioctl, -- 1.7.1