From 3ca5db072c770c950a816c46ef2330d9e0ced8a7 Mon Sep 17 00:00:00 2001 From: Suman Anna Date: Wed, 22 Oct 2014 17:22:29 -0500 Subject: [PATCH] iommu/omap: Make pagetable debugfs entry read-only Remove the writeability on the 'pagetable' debugfs entry, so that the mapping/unmapping into an OMAP IOMMU is only limited to actual client devices/drivers at kernel-level. Signed-off-by: Suman Anna Acked-by: Laurent Pinchart Signed-off-by: Joerg Roedel --- drivers/iommu/omap-iommu-debug.c | 48 ++------------------------------ 1 file changed, 2 insertions(+), 46 deletions(-) diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c index a520438182db..28de657e38c0 100644 --- a/drivers/iommu/omap-iommu-debug.c +++ b/drivers/iommu/omap-iommu-debug.c @@ -24,8 +24,6 @@ #include "omap-iopgtable.h" #include "omap-iommu.h" -#define MAXCOLUMN 100 /* for short messages */ - static DEFINE_MUTEX(iommu_debug_lock); static struct dentry *iommu_debug_root; @@ -82,39 +80,6 @@ static ssize_t debug_read_tlb(struct file *file, char __user *userbuf, return bytes; } -static ssize_t debug_write_pagetable(struct file *file, - const char __user *userbuf, size_t count, loff_t *ppos) -{ - struct iotlb_entry e; - struct cr_regs cr; - int err; - struct device *dev = file->private_data; - struct omap_iommu *obj = dev_to_omap_iommu(dev); - char buf[MAXCOLUMN], *p = buf; - - count = min(count, sizeof(buf)); - - mutex_lock(&iommu_debug_lock); - if (copy_from_user(p, userbuf, count)) { - mutex_unlock(&iommu_debug_lock); - return -EFAULT; - } - - sscanf(p, "%x %x", &cr.cam, &cr.ram); - if (!cr.cam || !cr.ram) { - mutex_unlock(&iommu_debug_lock); - return -EINVAL; - } - - omap_iotlb_cr_to_e(&cr, &e); - err = omap_iopgtable_store_entry(obj, &e); - if (err) - dev_err(obj->dev, "%s: fail to store cr\n", __func__); - - mutex_unlock(&iommu_debug_lock); - return count; -} - #define dump_ioptable_entry_one(lv, da, val) \ ({ \ int __err = 0; \ @@ -202,14 +167,6 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf, return bytes; } -#define DEBUG_FOPS(name) \ - static const struct file_operations debug_##name##_fops = { \ - .open = simple_open, \ - .read = debug_read_##name, \ - .write = debug_write_##name, \ - .llseek = generic_file_llseek, \ - }; - #define DEBUG_FOPS_RO(name) \ static const struct file_operations debug_##name##_fops = { \ .open = simple_open, \ @@ -219,7 +176,7 @@ static ssize_t debug_read_pagetable(struct file *file, char __user *userbuf, DEBUG_FOPS_RO(regs); DEBUG_FOPS_RO(tlb); -DEBUG_FOPS(pagetable); +DEBUG_FOPS_RO(pagetable); #define __DEBUG_ADD_FILE(attr, mode) \ { \ @@ -230,7 +187,6 @@ DEBUG_FOPS(pagetable); return -ENOMEM; \ } -#define DEBUG_ADD_FILE(name) __DEBUG_ADD_FILE(name, 0600) #define DEBUG_ADD_FILE_RO(name) __DEBUG_ADD_FILE(name, 0400) static int iommu_debug_register(struct device *dev, void *data) @@ -263,7 +219,7 @@ static int iommu_debug_register(struct device *dev, void *data) DEBUG_ADD_FILE_RO(regs); DEBUG_ADD_FILE_RO(tlb); - DEBUG_ADD_FILE(pagetable); + DEBUG_ADD_FILE_RO(pagetable); return 0; -- 2.34.1