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-rw-r--r--drivers/char/mem.c27
1 files changed, 16 insertions, 11 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index dcf6e31..964ff3b 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -109,24 +109,26 @@ static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
#endif
#ifdef CONFIG_NONPROMISC_DEVMEM
-static inline int range_is_allowed(unsigned long from, unsigned long to)
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
- unsigned long cursor;
+ u64 from = ((u64)pfn) << PAGE_SHIFT;
+ u64 to = from + size;
+ u64 cursor = from;
- cursor = from >> PAGE_SHIFT;
- while ((cursor << PAGE_SHIFT) < to) {
- if (!devmem_is_allowed(cursor)) {
- printk(KERN_INFO "Program %s tried to read /dev/mem "
- "between %lx->%lx.\n",
+ while (cursor < to) {
+ if (!devmem_is_allowed(pfn)) {
+ printk(KERN_INFO
+ "Program %s tried to access /dev/mem between %Lx->%Lx.\n",
current->comm, from, to);
return 0;
}
- cursor++;
+ cursor += PAGE_SIZE;
+ pfn++;
}
return 1;
}
#else
-static inline int range_is_allowed(unsigned long from, unsigned long to)
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
return 1;
}
@@ -181,7 +183,7 @@ static ssize_t read_mem(struct file * file, char __user * buf,
*/
ptr = xlate_dev_mem_ptr(p);
- if (!range_is_allowed(p, p+count))
+ if (!range_is_allowed(p >> PAGE_SHIFT, count))
return -EPERM;
if (copy_to_user(buf, ptr, sz))
return -EFAULT;
@@ -240,7 +242,7 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
*/
ptr = xlate_dev_mem_ptr(p);
- if (!range_is_allowed(p, p+sz))
+ if (!range_is_allowed(p >> PAGE_SHIFT, sz))
return -EPERM;
copied = copy_from_user(ptr, buf, sz);
if (copied) {
@@ -309,6 +311,9 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma)
if (!private_mapping_ok(vma))
return -ENOSYS;
+ if (!range_is_allowed(vma->vm_pgoff, size))
+ return -EPERM;
+
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
size,
vma->vm_page_prot);
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