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Commit 7991893d authored by Vikram Mulukutla's avatar Vikram Mulukutla
Browse files

drivers: soc: ramdump: Ensure aligned addresses are passed to copy_to_user 



ARMV8 architectures do not allow misaligned accesses
to device memory. Until an implementation of copy_to_user
that respects this requirement is available, ensure
that aligned addresses are passed in to copy_to_user.

Change-Id: Iea509094fe3f915310b50a471a467226a68460a2
Signed-off-by: default avatarVikram Mulukutla <markivx@codeaurora.org>
parent 1d63465e

drivers/soc/qcom/ramdump.c

+40 −8
Original line number Diff line number Diff line
@@ -99,10 +99,11 @@ static ssize_t ramdump_read(struct file *filep, char __user *buf, size_t count, 
{

	struct ramdump_device *rd_dev = container_of(filep->private_data,

				struct ramdump_device, device);

	void *device_mem = NULL;

	unsigned long data_left = 0;

	void *device_mem = NULL, *origdevice_mem = NULL;

	unsigned long data_left = 0, bytes_before, bytes_after;

	unsigned long addr = 0;

	size_t copy_size = 0;

	size_t copy_size = 0, alignsize;

	unsigned char *alignbuf = NULL, *finalbuf = NULL;

	int ret = 0;

	loff_t orig_pos = *pos;
@@ -143,6 +144,7 @@ static ssize_t ramdump_read(struct file *filep, char __user *buf, size_t count, 
	copy_size = min(count, (size_t)MAX_IOREMAP_SIZE);

	copy_size = min((unsigned long)copy_size, data_left);

	device_mem = ioremap_nocache(addr, copy_size);

	origdevice_mem = device_mem;



	if (device_mem == NULL) {

		pr_err("Ramdump(%s): Unable to ioremap: addr %lx, size %zd\n",
@@ -152,16 +154,44 @@ static ssize_t ramdump_read(struct file *filep, char __user *buf, size_t count, 
		goto ramdump_done;

	}



	if (copy_to_user(buf, device_mem, copy_size)) {

		pr_err("Ramdump(%s): Couldn't copy all data to user.",

	alignbuf = kzalloc(copy_size, GFP_KERNEL);

	if (!alignbuf) {

		pr_err("Ramdump(%s): Unable to alloc mem for aligned buf\n",

				rd_dev->name);

		iounmap(device_mem);

		rd_dev->ramdump_status = -1;

		ret = -ENOMEM;

		goto ramdump_done;

	}



	finalbuf = alignbuf;

	alignsize = copy_size;



	if ((unsigned long)device_mem & 0x7) {

		bytes_before = 8 - ((unsigned long)device_mem & 0x7);

		memcpy_fromio(alignbuf, device_mem, bytes_before);

		device_mem += bytes_before;

		alignbuf += bytes_before;

		alignsize -= bytes_before;

	}



	if (alignsize & 0x7) {

		bytes_after = alignsize & 0x7;

		memcpy(alignbuf, device_mem, alignsize - bytes_after);

		device_mem += alignsize - bytes_after;

		alignbuf += (alignsize - bytes_after);

		alignsize = bytes_after;

		memcpy_fromio(alignbuf, device_mem, alignsize);

	} else

		memcpy(alignbuf, device_mem, alignsize);



	if (copy_to_user(buf, finalbuf, copy_size)) {

		rd_dev->ramdump_status = -1;

		ret = -EFAULT;

		goto ramdump_done;

	}



	iounmap(device_mem);

	iounmap(origdevice_mem);

	kfree(finalbuf);

	*pos += copy_size;



	pr_debug("Ramdump(%s): Read %zd bytes from address %lx.",
@@ -170,6 +200,8 @@ static ssize_t ramdump_read(struct file *filep, char __user *buf, size_t count, 
	return *pos - orig_pos;



ramdump_done:

	iounmap(origdevice_mem);

	kfree(finalbuf);

	rd_dev->data_ready = 0;

	*pos = 0;

	complete(&rd_dev->ramdump_complete);