procfs: fix unintended truncation of returned mapped address
authorHATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Wed, 16 Oct 2013 20:47:04 +0000 (13:47 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Thu, 17 Oct 2013 04:35:53 +0000 (21:35 -0700)
Currently, proc_reg_get_unmapped_area truncates upper 32-bit of the
mapped virtual address returned from get_unmapped_area method in
pde->proc_fops due to the variable rv of signed integer on x86_64.  This
is too small to have vitual address of unsigned long on x86_64 since on
x86_64, signed integer is of 4 bytes while unsigned long is of 8 bytes.
To fix this issue, use unsigned long instead.

Fixes a regression added in commit c4fe24485729 ("sparc: fix PCI device
proc file mmap(2)").

Signed-off-by: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Tested-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/proc/inode.c

index 9f8ef9b..6c501c4 100644 (file)
@@ -288,7 +288,7 @@ static int proc_reg_mmap(struct file *file, struct vm_area_struct *vma)
 static unsigned long proc_reg_get_unmapped_area(struct file *file, unsigned long orig_addr, unsigned long len, unsigned long pgoff, unsigned long flags)
 {
        struct proc_dir_entry *pde = PDE(file_inode(file));
-       int rv = -EIO;
+       unsigned long rv = -EIO;
        unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
        if (use_pde(pde)) {
                get_unmapped_area = pde->proc_fops->get_unmapped_area;