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Commit c5cf5c53 authored by Suman Anna's avatar Suman Anna Committed by Joerg Roedel
Browse files

iommu/omap: Fix bus error on debugfs access of unattached IOMMU 



Any debugfs access on an OMAP IOMMU that is not enabled (done during
attach) results in a bus error due to access of registers without
the clock or the reset enabled for the respective IOMMU. So, add a
check to make sure the IOMMU is enabled/attached by a client device.
This gracefully prints a "Operation not permitted" trace when the
corresponding IOMMU is not enabled.

Signed-off-by: default avatarSuman Anna <s-anna@ti.com>
Acked-by: default avatarLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent f24d9ad3

drivers/iommu/omap-iommu-debug.c

+14 −0
Original line number Diff line number Diff line
@@ -24,6 +24,11 @@ static DEFINE_MUTEX(iommu_debug_lock); 


static struct dentry *iommu_debug_root;



static inline bool is_omap_iommu_detached(struct omap_iommu *obj)

{

	return !obj->domain;

}



static ssize_t debug_read_regs(struct file *file, char __user *userbuf,

			       size_t count, loff_t *ppos)

{
@@ -31,6 +36,9 @@ static ssize_t debug_read_regs(struct file *file, char __user *userbuf, 
	char *p, *buf;

	ssize_t bytes;



	if (is_omap_iommu_detached(obj))

		return -EPERM;



	buf = kmalloc(count, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;
@@ -54,6 +62,9 @@ static ssize_t debug_read_tlb(struct file *file, char __user *userbuf, 
	char *p, *buf;

	ssize_t bytes, rest;



	if (is_omap_iommu_detached(obj))

		return -EPERM;



	buf = kmalloc(count, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;
@@ -139,6 +150,9 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf, 
	char *p, *buf;

	size_t bytes;



	if (is_omap_iommu_detached(obj))

		return -EPERM;



	buf = (char *)__get_free_page(GFP_KERNEL);

	if (!buf)

		return -ENOMEM;