diff options
| -rw-r--r-- | drivers/char/mem.c | 27 |
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); |
