diff options
| -rw-r--r-- | fs/sysfs/bin.c | 42 |
1 files changed, 31 insertions, 11 deletions
diff --git a/fs/sysfs/bin.c b/fs/sysfs/bin.c index 006fc64..66f6e58 100644 --- a/fs/sysfs/bin.c +++ b/fs/sysfs/bin.c @@ -61,6 +61,7 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) int size = dentry->d_inode->i_size; loff_t offs = *off; int count = min_t(size_t, bytes, PAGE_SIZE); + char *temp; if (size) { if (offs > size) @@ -69,23 +70,33 @@ read(struct file *file, char __user *userbuf, size_t bytes, loff_t *off) count = size - offs; } + temp = kmalloc(count, GFP_KERNEL); + if (!temp) + return -ENOMEM; + mutex_lock(&bb->mutex); count = fill_read(dentry, bb->buffer, offs, count); - if (count < 0) - goto out_unlock; + if (count < 0) { + mutex_unlock(&bb->mutex); + goto out_free; + } - if (copy_to_user(userbuf, bb->buffer, count)) { + memcpy(temp, bb->buffer, count); + + mutex_unlock(&bb->mutex); + + if (copy_to_user(userbuf, temp, count)) { count = -EFAULT; - goto out_unlock; + goto out_free; } pr_debug("offs = %lld, *off = %lld, count = %d\n", offs, *off, count); *off = offs + count; - out_unlock: - mutex_unlock(&bb->mutex); + out_free: + kfree(temp); return count; } @@ -118,6 +129,7 @@ static ssize_t write(struct file *file, const char __user *userbuf, int size = dentry->d_inode->i_size; loff_t offs = *off; int count = min_t(size_t, bytes, PAGE_SIZE); + char *temp; if (size) { if (offs > size) @@ -126,19 +138,27 @@ static ssize_t write(struct file *file, const char __user *userbuf, count = size - offs; } - mutex_lock(&bb->mutex); + temp = kmalloc(count, GFP_KERNEL); + if (!temp) + return -ENOMEM; - if (copy_from_user(bb->buffer, userbuf, count)) { + if (copy_from_user(temp, userbuf, count)) { count = -EFAULT; - goto out_unlock; + goto out_free; } + mutex_lock(&bb->mutex); + + memcpy(bb->buffer, temp, count); + count = flush_write(dentry, bb->buffer, offs, count); + mutex_unlock(&bb->mutex); + if (count > 0) *off = offs + count; - out_unlock: - mutex_unlock(&bb->mutex); +out_free: + kfree(temp); return count; } |