*/
static inline int uncached_access(struct file *file, unsigned long addr)
{
-#if defined(__i386__)
- /*
- * On the PPro and successors, the MTRRs are used to set
- * memory types for physical addresses outside main memory,
- * so blindly setting PCD or PWT on those pages is wrong.
- * For Pentiums and earlier, the surround logic should disable
- * caching for the high addresses through the KEN pin, but
- * we maintain the tradition of paranoia in this code.
- */
- if (file->f_flags & O_SYNC)
- return 1;
- return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
- test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) )
- && addr >= __pa(high_memory);
-#elif defined(__x86_64__)
- /*
- * This is broken because it can generate memory type aliases,
- * which can cause cache corruptions
- * But it is only available for root and we have to be bug-to-bug
- * compatible with i386.
- */
- if (file->f_flags & O_SYNC)
- return 1;
- /* same behaviour as i386. PAT always set to cached and MTRRs control the
- caching behaviour.
- Hopefully a full PAT implementation will fix that soon. */
- return 0;
-#elif defined(CONFIG_IA64)
+#if defined(CONFIG_IA64)
/*
* On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
*/
}
#endif
+#ifdef CONFIG_NONPROMISC_DEVMEM
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+ u64 from = ((u64)pfn) << PAGE_SHIFT;
+ u64 to = from + size;
+ u64 cursor = from;
+
+ 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 += PAGE_SIZE;
+ pfn++;
+ }
+ return 1;
+}
+#else
+static inline int range_is_allowed(unsigned long pfn, unsigned long size)
+{
+ return 1;
+}
+#endif
+
+void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr)
+{
+}
+
/*
* This funcion reads the *physical* memory. The f_pos points directly to the
* memory location.
sz = min_t(unsigned long, sz, count);
+ if (!range_is_allowed(p >> PAGE_SHIFT, count))
+ return -EPERM;
+
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
+ if (!ptr)
+ return -EFAULT;
- if (copy_to_user(buf, ptr, sz))
+ if (copy_to_user(buf, ptr, sz)) {
+ unxlate_dev_mem_ptr(p, ptr);
return -EFAULT;
+ }
+
+ unxlate_dev_mem_ptr(p, ptr);
+
buf += sz;
p += sz;
count -= sz;
sz = min_t(unsigned long, sz, count);
+ if (!range_is_allowed(p >> PAGE_SHIFT, sz))
+ return -EPERM;
+
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
+ if (!ptr) {
+ if (written)
+ break;
+ return -EFAULT;
+ }
copied = copy_from_user(ptr, buf, sz);
if (copied) {
written += sz - copied;
+ unxlate_dev_mem_ptr(p, ptr);
if (written)
break;
return -EFAULT;
}
+
+ unxlate_dev_mem_ptr(p, ptr);
+
buf += sz;
p += sz;
count -= sz;
return written;
}
+int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
+ unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
+{
+ return 1;
+}
+
#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
}
#endif
+void __attribute__((weak))
+map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
+{
+ /* nothing. architectures can override. */
+}
+
+void __attribute__((weak))
+unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
+{
+ /* nothing. architectures can override. */
+}
+
+static void mmap_mem_open(struct vm_area_struct *vma)
+{
+ map_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static void mmap_mem_close(struct vm_area_struct *vma)
+{
+ unmap_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
+static struct vm_operations_struct mmap_mem_ops = {
+ .open = mmap_mem_open,
+ .close = mmap_mem_close
+};
+
static int mmap_mem(struct file * file, struct vm_area_struct * vma)
{
size_t size = vma->vm_end - vma->vm_start;
if (!private_mapping_ok(vma))
return -ENOSYS;
+ if (!range_is_allowed(vma->vm_pgoff, size))
+ return -EPERM;
+
+ if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
+ &vma->vm_page_prot))
+ return -EINVAL;
+
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
size,
vma->vm_page_prot);
+ vma->vm_ops = &mmap_mem_ops;
+
/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
if (remap_pfn_range(vma,
vma->vm_start,
vma->vm_pgoff,
size,
- vma->vm_page_prot))
+ vma->vm_page_prot)) {
+ unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
return -EAGAIN;
+ }
return 0;
}
return splice_from_pipe(pipe, out, ppos, len, flags, pipe_to_null);
}
-#ifdef CONFIG_MMU
-/*
- * For fun, we are using the MMU for this.
- */
-static inline size_t read_zero_pagealigned(char __user * buf, size_t size)
-{
- struct mm_struct *mm;
- struct vm_area_struct * vma;
- unsigned long addr=(unsigned long)buf;
-
- mm = current->mm;
- /* Oops, this was forgotten before. -ben */
- down_read(&mm->mmap_sem);
-
- /* For private mappings, just map in zero pages. */
- for (vma = find_vma(mm, addr); vma; vma = vma->vm_next) {
- unsigned long count;
-
- if (vma->vm_start > addr || (vma->vm_flags & VM_WRITE) == 0)
- goto out_up;
- if (vma->vm_flags & (VM_SHARED | VM_HUGETLB))
- break;
- count = vma->vm_end - addr;
- if (count > size)
- count = size;
-
- zap_page_range(vma, addr, count, NULL);
- if (zeromap_page_range(vma, addr, count, PAGE_COPY))
- break;
-
- size -= count;
- buf += count;
- addr += count;
- if (size == 0)
- goto out_up;
- }
-
- up_read(&mm->mmap_sem);
-
- /* The shared case is hard. Let's do the conventional zeroing. */
- do {
- unsigned long unwritten = clear_user(buf, PAGE_SIZE);
- if (unwritten)
- return size + unwritten - PAGE_SIZE;
- cond_resched();
- buf += PAGE_SIZE;
- size -= PAGE_SIZE;
- } while (size);
-
- return size;
-out_up:
- up_read(&mm->mmap_sem);
- return size;
-}
-
static ssize_t read_zero(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
- unsigned long left, unwritten, written = 0;
+ size_t written;
if (!count)
return 0;
if (!access_ok(VERIFY_WRITE, buf, count))
return -EFAULT;
- left = count;
-
- /* do we want to be clever? Arbitrary cut-off */
- if (count >= PAGE_SIZE*4) {
- unsigned long partial;
+ written = 0;
+ while (count) {
+ unsigned long unwritten;
+ size_t chunk = count;
- /* How much left of the page? */
- partial = (PAGE_SIZE-1) & -(unsigned long) buf;
- unwritten = clear_user(buf, partial);
- written = partial - unwritten;
- if (unwritten)
- goto out;
- left -= partial;
- buf += partial;
- unwritten = read_zero_pagealigned(buf, left & PAGE_MASK);
- written += (left & PAGE_MASK) - unwritten;
+ if (chunk > PAGE_SIZE)
+ chunk = PAGE_SIZE; /* Just for latency reasons */
+ unwritten = clear_user(buf, chunk);
+ written += chunk - unwritten;
if (unwritten)
- goto out;
- buf += left & PAGE_MASK;
- left &= ~PAGE_MASK;
- }
- unwritten = clear_user(buf, left);
- written += left - unwritten;
-out:
- return written ? written : -EFAULT;
-}
-
-static int mmap_zero(struct file * file, struct vm_area_struct * vma)
-{
- int err;
-
- if (vma->vm_flags & VM_SHARED)
- return shmem_zero_setup(vma);
- err = zeromap_page_range(vma, vma->vm_start,
- vma->vm_end - vma->vm_start, vma->vm_page_prot);
- BUG_ON(err == -EEXIST);
- return err;
-}
-#else /* CONFIG_MMU */
-static ssize_t read_zero(struct file * file, char * buf,
- size_t count, loff_t *ppos)
-{
- size_t todo = count;
-
- while (todo) {
- size_t chunk = todo;
-
- if (chunk > 4096)
- chunk = 4096; /* Just for latency reasons */
- if (clear_user(buf, chunk))
- return -EFAULT;
+ break;
buf += chunk;
- todo -= chunk;
+ count -= chunk;
cond_resched();
}
- return count;
+ return written ? written : -EFAULT;
}
static int mmap_zero(struct file * file, struct vm_area_struct * vma)
{
+#ifndef CONFIG_MMU
return -ENOSYS;
+#endif
+ if (vma->vm_flags & VM_SHARED)
+ return shmem_zero_setup(vma);
+ return 0;
}
-#endif /* CONFIG_MMU */
static ssize_t write_full(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
static int __init chr_dev_init(void)
{
int i;
+ int err;
+
+ err = bdi_init(&zero_bdi);
+ if (err)
+ return err;
if (register_chrdev(MEM_MAJOR,"mem",&memory_fops))
printk("unable to get major %d for memory devs\n", MEM_MAJOR);